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      Volume 39,2022 Issue 4
        Research and Development
      • WEI Yongbin, JIN Jie, LIU Junfeng, GENG Guofeng

        2022,39(4):261-267, DOI: 10.7535/hbgykj.2022yx04001

        Abstract:

        In order to further optimize the spray spheroidization process and improve the availability of Mg,the application effect of ductile iron pile and the relationship between molten iron temperature,spheroidization depth and the availability of Mg spheroidizing agent were studied.The results show that the residual S content after spheroidization can be steadily reduced to less than 0.01%(mass fraction),and spheroidization degeneration doesn′t occur when the residual Mg content is greater than 0.05%(mass fraction).During spheroidization,the lower the temperature of molten iron and the greater the spheroidization depth are,the greater the availability of Mg by molten iron is.When the molten iron temperature is 1 460 ℃ and spheroidization depth is 1.32 m,the Mg availability can be over 50%.The spray spheroidization process takes into account the characteristics of simple and reliable equipment,easy maintenance and flexible adjustment of spheroidization dose.It is applied to the production field of fast-paced and large-scale ductile iron pipes to reduce the cost of spray spheroidization process,which provides a certain reference for the popularization and application of spray spheroidization process in the ductile iron industry.

      • ZHANG Yongdi, CHANG Weichun, GUO Xu, CHEN Hongmin, CHEN Haipeng

        2022,39(4):268-273, DOI: 10.7535/hbgykj.2022yx04002

        Abstract:

        In order to seek a new repair method to adapt to the girth weld defects of high-steel grade oil and gas pipelines and overcome the limitations of traditional repair technology,the feasibility of arc additive manufaturing technology for girth weld repair of oil and gas pipeline was poposed.Firstly,after comparing and analyzing the three new repair technologies of laser cladding,cold spraying and arc additive manufacturing,the arc additive manufacturing technology was used for experimental research.Secondly,the 22 mm thick specimens were intercepted along the axis at the X80 pipe girth weld,the defects with 60° groove angle and 11 mm groove depth at the girth weld were made,and then arc additive manufacturing cold metal transition process and ER50-6 weld wire were used for repair experiments.Finally,the mechanical test of the repair specimens was carried out,and the experimental data and fracture morphology were analyzed.The test results show that the tensile strength of the specimen after arc additive manufacturing repair is up to 639 MPa,and the strength matches the pipe substrate.The research results show that the feasibility for repairing of girth weld defects of X80 oil and gas pipelines by arc additive manufacturing technology,it has the characteristics of high deposition efficiency,low cost and mechanical properties can meet the repair requirements.It has important practical significance in the feasibility and economy of repair of girth weld defects in high-steel oil and gas pipelines.

      • WEI Ziqiu, LIN Yanmin, LI Mingfang, BAI Shiyu

        2022,39(4):274-281, DOI: 10.7535/hbgykj.2022yx04003

        Abstract:

        In order to reduce the cost of cold chain logistics distribution and ensure customer satisfaction and carbon emission costs to meet the requirements of enterprises,taking full account of customer soft time window constraints,distance,fresh deterioration and other multiple influencing factors,a low-carbon cold chain logistics path optimization model considering customer ssatisfaction was constructed.Combined with fixed cost,carbon emission cost,damage cost,cold storage cost,transportation cost and time window cost,genetic algorithm was used to solve it,and practical examples were used to verify it.The experimental results show that compared with the route optimization without considering satisfaction,the cold chain logistics route optimization with the total cost as the goal can reduce the transportation distance by 23 km and the total distribution cost by 2.72% on average.At the same time,the result is better than the solution with low carbon as the goal.This model not only improves customer satisfaction,but also finally achieves the overall goal of reducing the total cost of distribution and carbon emissions in logistics activities.This study provides inspiration for the service-oriented and low-carbon transformation development of the cold chain logistics industry,plays a theoretical guiding role in the study of the sustainable development of the logistics industry,and provides an effective technical route for logistics and transportation enterprises to obtain a higher level of service quality and economic benefits.

      • ZHAO Xiaolei, XIAO Weizhou

        2022,39(4):282-289, DOI: 10.7535/hbgykj.2022yx04004

        Abstract:

        In order to help station operators conduct a comprehensive evaluation of the station service level,so as to reflect the effect of different passenger flow organization measures,and then make a plan choice,a comprehensive service level indicator system was established from the three aspects of basic pedestrian travel experience,walking experience and equipment and facilities experience,and a comprehensive evaluation method for the service level of the transfer station was proposed based on the extension theory.Four passenger flow organization scenarios were given for the passenger flow problem,and the Suzhou Rail Transit Shihu East Road Station is simulated by using Anylogic software to obtain various indicators under different organizational scenarios.Then the comprehensive evaluation and analysis of each scenario is carried out based on the extension matter element method.Combined with the correlation degree matrix,indicators and simulation effects,the best passenger flow organization method is determined as scenario 1,which can improve the comprehensive service level from the "general" to "good".The comprehensive evaluation model established by the extension matter element method can provide reference for the station managers to take organizational measures,and can easily provide technical support for the station operation organization.

      • Summary and Review
      • YANG Sha, LIU Mingsong, YANG Ying, LIU Wenqing

        2022,39(4):290-299, DOI: 10.7535/hbgykj.2022yx04005

        Abstract:

        The research progress of TEMPO system in the construction of uronic acid by catalytic oxidation in recent years was introduced in this paper,the basic principles of TEMPO/hypochlorite,TEMPO/BAIB system,other TEMPO/co-oxidant systems and TEMPO/transition metal/aerobic system were briefly described,and their application scope was analyzed.Then,the reaction mechanism,application scope of substrates and advantages and disadvantages of the four TEMPO oxidation systems of primary hydroxyl to uronic acid were further compared.The analysis shows that TEMPO catalytic oxidation can solve the problems of environmental pollution faced by heavy metal oxidants in traditional processes.Based on this,the development outlook is prospected,and it is pointed out that TEMPO oxidation can be further studied in the following aspects in the future.1) It is essential to carry out the TEMPO/hypochlorite oxidation process research in the aim of avoiding or reducing the introduction of inorganic salts,reducing the adverse effect on product purity and industrial waste salt pollution to the environment;2) Further studies to optimize the solvent system in TEMPO/BAIB combination should be performed so as to provide basis for the realization of green and clean production;3) Systematical and intensive research of the emerging TEMPO aerobic oxidation system should be investigated in order to realize its application and promotion in the uronic acid oxidation.

      • 人工智能专栏
      • XIE Yanhong, ZHANG Haoran, ZHANG Cheng, LI Yuan

        2022,39(4):300-309, DOI: 10.7535/hbgykj.2022yx04006

        Abstract:

        Aiming at the problem of low fault detection rate of multi-modal dynamic process by support vector data description (SVDD) method,a fault detection method based on dynamic SVDD based on double local neighborhood standardization (DLNS-DSVDD) was proposed.Firstly,the DLNS method was used to standardize samples to generate a standard data set.Secondly,the dynamic method was used to construct the standard data set into a dynamic matrix.Finally,the SVDD method was used to establish statistics based on spatial distance for fault detection,and the DLNS-DSVDD method was used to simulate a numerical example and the Tennessee-Eastman (TE) process,which was compared with the traditional method.The results show that the DLNS-DSVDD method has a higher fault detection rate on the premise of lower false alarm rate.The average false alarm rate is 2.2%,which is 2.1% lower than that of the SVDD method,and the average fault detection rate is 88.2%,which is 38.5% higher than the SVDD method.It is proved that the method proposed in this paper can effectively monitor the chemical production process with multi-modal dynamic characteristics.The DLNS-DSVDD method can effectively eliminate the multi-modal structure of the data and accurately capture the dynamic information in the sample,which provides a reference for improving the fault detection performance of the SVDD method in the multi-modal dynamic process.

      • MA Derong, CAO Guozhong, YANG Wendan

        2022,39(4):310-319, DOI: 10.7535/hbgykj.2022yx04007

        Abstract:

        In order to help enterprises recognize the technology with the most potential before technology research and development and improve the success probability of product radical innovation,a quantitative method for recognizing radical innovation opportunities in the fuzzy front-end stage was proposed.Firstly,through literature research,the path characteristics of product radical innovation were determined,the relevant influencing factors of product radical innovation were extracted,and the characteristic system of product radical innovation opportunity recognition was extracted and constructed by establishing interpretive structure model (ISM).Then,the characteristics of radical innovation cases and non radical innovation cases were compared.Finally,taking the change trend of each characteristic factor as the independent variable,a neural network was established to fit the sample data,and a product radical innovation opportunity recognition model was constructed.The results show that the model can effectively recognize the radical innovation opportunities of products,and can be applied to the fuzzy front-end stage of product innovation design process to provide important guidance for enterprises to recognize opportunities more effectively in radical innovation projects.

      • 通信技术与智能服务专栏
      • DONG Yanlei, GUAN Junpeng, ZHANG Jianjun, ZHANG Yunzuo

        2022,39(4):320-327, DOI: 10.7535/hbgykj.2022yx04008

        Abstract:

        In order to solve the problems of incomplete and inaccurate operation situation when GEO broadband,GEO mobile,and LEO constellationsatellite communication systems are integratedly used,a situation analysis technology of multi-satellite communication system based on decision fusion was designed.Firstly,drawing on the theory of digital twins,the digital space model of board level,device level,node level,network level and application level was established.Secondly,data features were extracted to obtain high-quality data samples.Finally,through the decision fusion analysis method,the data samples were preliminarily analyzed by using a variety of algorithms,and then the analysis results of different algorithms were fused to get the final results.The results reveal that based on the decision fusion analysis,better analysis results are obtained for different index topics of real multi-satellite communication system.The analysis results obtained by decision fusion can help the operation and maintenance personnel of multi-satellite communication system better optimize the operation state of multi-satellite communication system.

      • CHANG Xin, LI Yanbin, ZHAO Yan, DU Yufeng, LIU Donghui

        2022,39(4):328-334, DOI: 10.7535/hbgykj.2022yx04009

        Abstract:

        In order to generate the intelligentized collaborative penetration strategy of heterogeneous multiple UAVs,a novel cooperative penetration method of heterogeneous multiple unmanned aerial vehicles based on multi-agent asynchronous imitative deep deterministic policy gradient algorithm (MA2IDDPG) was proposed.Firstly,asynchronous parallel framework was adopted based on the traditional DDPG method to improve the collection efficiency of experience data.Secondly,the attractant reward function based on expert experience knowledge and the descriptive reward function based on results were constructed respectively.Thirdly,through the phased training,the collaborative penetration strategy generated by the deep neural network could quickly reach the level of expert experience and knowledge,and the level of confrontation could be further improved.Finally,a heterogeneous multi-UAV cooperative penetration environment was constructed in simulation experiments,and the countermeasures performance of the improved method and the DDPG method was compared.The experiment results show that MA2IDDPG method can effectively generate the cooperative penetration strategy of multiple UAVs,and the performance of the proposed method is more stable and better than that of the traditional method in the training stage.The innovative MA2IDDPG method can be effectively applied in the field of UAV swarm control,especially for the study of intelligent control methods of heterogeneous UAV swarm.

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      Volume 39,2022 Issue 4
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      • Safety risk assessment of hazardous chemicals in highway Transportation based on fuzzy linkage degree

        韦相宇, 田世祥, 代张音, 范芮雯

        Abstract:

        In order to effectively reduce the risk of road transportation accidents of hazardous chemicals and improve the safety control ability of road transportation of hazardous chemicals, a safety risk assessment index system for road transportation of hazardous chemicals containing 23 dynamic and static indexes was constructed, and the combined weights were used to assign weights to the evaluation indexes. Based on the theory of set pair analysis, the expert scoring score and combination weight were deeply analyzed, the concept of comprehensive difference coefficient was introduced to determine the fuzzy connection degree, and a risk assessment method for highway transportation safety of hazardous chemicals was proposed. The results show that: except for the dangerous chemical factors, the risk of other level indicators all have a rising trend, and the risk of driver factor is especially obvious. The overall risk state of dangerous chemical highway transportation is at level 9 of slight negative potential, which is higher risk, which is consistent with the actual situation. It shows that the method can realize the dynamic and static risk assessment of dangerous chemical transportation by road, and provide some reference value for the risk study of dangerous chemical transportation by road.

        • 1
      • Students' classroom state detection based on expression recognition technology

        苏悦, 杨春金, 王建霞

        Abstract:

        Aiming at the problem that it is difficult to monitor the students' learning state under the online teaching mode, a method of detecting students' classroom state based on expression recognition technology is proposed. First, the camera is used to capture the classroom images of students at regular intervals, and the collected images are preprocessed to recognize and obtain face data; Secondly, combining the expression recognition method to analyze the students' class state; Finally, the data visualization is introduced to the teachers, who adjust the teaching plan according to the students' class status to improve the teaching quality. In order to reduce the computational power consumption and improve the accuracy of expression recognition, a lightweight model mini_Xception with channel attention mechanism is adopted as the expression recognition model. The model classifies facial expressions into seven types, and then divides them into three states: positive, negative and neutral to judge students' class participation and concentration. The accuracy of the model is trained and verified by using Fer2013 and CK + facial expression databases, and compared with the existing expression recognition methods. The experimental results show that the recognition rate of the training set and verification set of the model on Fer2013 and CK + is improved, which can be applied to online teaching and has practical application value for improving the learning efficiency of students.

        • 1
      • Beamforming based on Maximum Signal-to-Leakage-Noise ratio algorithm with improved power allocation

        赵子涛, 宋志群, 王荆宁, 李勇

        Abstract:

        In the traditional maximum signal-to-leakage-noise ratio algorithm, the transmitted power is distributed equally to all users without power distribution according to the channel conditions. However, in the actual transmission process , due to the differences between the transmission environments of each user , simply distributing power evenly does not guarantee the communication needs of users in poor transmission environment , and reduces the fairness of the system. Aiming at the lack of fairness consideration in the traditional algorithm, a maximum signal-to-leakage-noise ratio beamforming algorithm is proposed to improve the power distribution mode, which can increase the fairness of the system by setting the corresponding distribution standard and power threshold value. Finally, the simulation results show that fairness of the improved algorithm is significantly higher than that of the average power distribution.

        • 1
      • Feature Extraction Method Of Optical Cable Identification Based on HHT And PCA

        韩晓伟

        Abstract:

        By detecting the signal amplitude to identify the target cable is a common method of optical cable identification, which is prone to lead to false positives in a seriously disturbed environment. Considering the nonlinear and nonstationary time-domain characteristics of the target interference signal, a signal processing method combining Hilbert-Huang transform(HHT) and PCA(Principal Component Analysis) is proposed. The echo interference signal is decomposed by EMD to obtain the intrinsic mode components, which are designed as column vectors to construct the sample matrix. The principal component analysis algorithm is used to reduce the noise. The denoised signal is decomposed by HHT to obtain the characteristic signal to accomplish the optical cable identification. The results show that the method can effectively remove the noise and improve the signal-to-noise ratio.

        • 1
      • Study on snow-prevention effect prediction and design parameter optimization of snow retaining wall of highway in the form of cutting

        奚文彬, 李亚军, 常江芳, 刘亚男, 钱家珺, 李志达

        Abstract:

        Snow drifting disaster seriously affects the smoothness and safety of expressway, which is one of the difficult problems faced by expressway management and operation. Aiming at the snow damage problem of snow drifting in the cutting of Yanchong expressway, this paper studies the snow distribution law of cutting under protective measures of snow retaining wall, optimizes the setting scheme of cutting snow retaining wall at the entrance of Jinjiazhuang spiral tunnel, and evaluates the snow prevention effect of snow retaining wall. Results show that factors affecting the snow volume fraction caused by snow drifting disaster include the wind speed, the cutting depth, the cutting slope ratio, the snow retaining wall height and the snow retaining wall layout distance. Among them, the cutting slope ratio has the greatest impact, followed by the snow retaining wall height, the cutting depth, the wind speed, the combination of wind speed-snow retaining wall height, the snow retaining wall layout distance and the combination of snow retaining wall height-snow retaining wall layout distance, while the combination of wind speed-snow retaining wall layout distance has the least impact. The optimal height of snow drifting retaining wall at the entrance of Jinjiazhuang spiral tunnel is 6m, and the optimal distance between retaining wall and embankment is 90m. When the snow retaining wall is set, the snow retaining wall can block a certain amount of snow and change the distribution of snow volume fraction, resulting in a 12.36% reduction in the cutting section compared with that without snow retaining wall, which proves that optimizing the layout of snow retaining wall can play a better snow prevention effect. The research can provide a convenient and rapid method and scientific basis for the setting of snow drifting snow retaining wall.

        • 1
      • Research on new repair technology for girth welds of oil and gas pipelines

        张永弟, 常维纯, 郭旭, 陈洪民, 陈海鹏, 贾康, 孙宝钰

        Abstract:

        The purpose of the paper is to seek a new repair method to adapt to repair the ring weld defects of high-steel grade oil and gas pipelines and overcome the limitations of traditional repair technologies. Firstly, laser cladding, cold spraying and arc additive manufacturing which three new repair technologies are compared and analyzed, arc additive manufacturing technology has high feasibility for oil and gas pipeline ring weld repair. Secondly, the 22 mm thick specimens are intercepted along the axis at the X80 pipe girth weld, the defects with 60° groove angle and 11 mm groove depth at the girth weld are made, and then arc additive manufacturing cold metal transfer process and ER50-6 weld wire were used for repair experiments. Finally, the mechanical test of the repair specimens was carried out, and the test results showed that the tensile strength of the specimen after arc additive manufacturing repair was up to 639Mpa, and the strength matched the pipe substrate, which provides certain reference value for repairing girth weld of high-steel grade oil and gas pipelines.

        • 1
      • Cooperative Penetration Method of Heterogeneous Multiple Unmanned Aerial Vehicles based on Multi-agent Asynchronous Imitative Deep Deterministic Policy Gradient Algorithm

        畅 鑫, 李艳斌, 赵 研, 杜宇峰, 刘东辉

        Abstract:

        In order to generate the collaborative penetration strategy of heterogeneous multiple UAVs, a multi-agent asynchronous imitative deep deterministic policy gradient (MA2IDDPG) is proposed. Firstly, asynchronous parallel framework is adopted to improve DDPG algorithm to improve the collection efficiency of empirical data. Then, a shared experience pool is constructed to increase the diversity of experience data and improve the learning efficiency of agents. Secondly, the pulling reward based on expert experiential knowledge and the descriptive reward based on task result are constructed and utilized in stages to further improve the intelligence level after the multi-agent reaches the expert knowledge level quickly. Finally, in the collaborative penetration environment of heterogeneous UAVs, the improved algorithm is verified from the perspective of mission achievement. Experimental results show that the improved algorithm can effectively generate the cooperative penetration strategy of heterogeneous multiple UAVs.

        • 1
      • Situation analysis technology of multi-satellite communication system based on decision fusion

        董彦磊, 关俊鹏, 张建君, 张云佐

        Abstract:

        In order to solve the problems of incomplete and inaccurate operation situation when GEO broadband, GEO mobile, and LEO constellation satellite communication systems are integratedly used, a situation analysis technology of multi-satellite communication system based on decision fusion is proposed. Firstly, drawing on the theory of digital twins, the digital space model of board level, device level, node level, network level and application level is established. Secondly, data features are extracted to obtain high-quality data samples. Finally, through the decision fusion analysis method, the data samples are preliminarily analyzed by using a variety of algorithms, and then the analysis results of different algorithms are fused to get the final result. The results reveal that based on the decision fusion analysis, good analysis results are obtained for different index topics of real multi-satellite communication system. The analysis results obtained by decision fusion can help the operation and maintenance personnel of multi-satellite communication system better optimize the operation state of multi-satellite communication system.

        • 1
      • Service level evaluation of metro transfer stations based on extension and matter element method

        赵晓磊, 肖为周

        Abstract:

        In order to help station operators to conduct a comprehensive evaluation of the station service level, to reflect the effect of different passenger flow organization measures and then make a plan choice, starting from the three aspects of basic pedestrian travel experience, walking experience and equipment and facilities experience, a comprehensive service level index system is established, and a comprehensive evaluation method for the service level of the transfer station is proposed based on the extension theory. Anylogic software is used to simulate the Shihu East Road Station of Suzhou Rail Transit, and four passenger flow organization scenarios are given for the passenger flow problem, and then the comprehensive evaluation and analysis of each scenario is carried out based on the extendable material element method, the reliability of the method is verified, and the technical support is provided for the station operation organization.

        • 1
      • Research on opportunity recognition of product radical innovation based on neural networks

        马德荣, 曹国忠, 杨雯丹

        Abstract:

        In order to help enterprises recognize the technology with the most potential before technology research and development and improve the success probability of product radical innovation, a quantitative method for recognizing radical innovation opportunities in the fuzzy front-end stage is proposed. Firstly, through literature research, determine the path characteristics of product radical innovation, extract the relevant influencing factors of product radical innovation, and extract and construct the characteristic system of product radical innovation opportunity recognition by establishing interpretive structure model (ISM). Then, the characteristics of radical innovation cases and non radical innovation cases are compared. Taking the change trend of each characteristic factor as the independent variable, a neural network is established to fit the sample data, and a product radical innovation opportunity recognition model is constructed. The results show that the model can effectively recognize the radical innovation opportunities of products, and can be applied to the fuzzy front-end stage of product innovation design process to provide important guidance for enterprises to recognize opportunities more effectively in radical innovation projects.

        • 1
      • Research on the design of a new steel tile roof snow remover machine

        赵自更

        Abstract:

        Aiming at the northern winter snowstorm, in order to solve the steel tile roof collapse phenomenon caused by the snow, to design a new type of steel tile roof snow removal machine. Proposed the overall design of snow removal and thermal insulation , developed a process route of snow removal and thermal insulation, the mechanical structure of the snow removal machine has been design and motion analysis. UG was used for three-dimensional modeling of snow throwers structure and motion simulation analysis, ANSYS Workbench was used for part finite element analysis, reasonableness test design. The results show that the designed snow removal machine can automatically steel tile roof snow removal, snow removal efficiency was about 25 times than manual, no snow removal uneven problems. The design of the snow remover machine had changed the traditional manual snow removal ,structure is reliable, easy to operate, and highly efficient. It can provide a new solution for the automatic snow removal of other inclined roofs.

        • 1
      • Digital Design of Personalized Rehabilitation Brace for Anterior Cruciate Ligament

        张永弟, 贾康, 孙宝钰, 杨光, 董威, 冯岩

        Abstract:

        In order to help patients with knee anterior cruciate ligament injury or rupture recover quickly, a personalized rehabilitation brace was designed. Firstly, Using CT and MRI images of knee joint, the three-dimensional knee joint model under normal and broken anterior cruciate ligament was constructed by using software such as mimics and 3-matic. Secondly, ANSYS was used to analyze the stress changes of the internal and lateral collateral ligaments and posterior cruciate ligaments under fixed external loads when the knee flexion was 0°, 30°, 60° and 90°.Analysis showed that anterior cruciate ligament rupture significantly increased the stress of the medial, lateral and posterior cruciate ligaments of the knee and the displacement of the femur relative to the tibia. Finally, based on the latest evidence-based medical evidence and clinical experience, a knee rehabilitation brace for anterior cruciate ligament injury was designed by using forward and reverse modeling techniques. Through virtual wearable analysis, the designed brace can effectively reduce the excessive displacement of knee joint caused by anterior cruciate ligament rupture and the stress of other ligaments, and can actively promote the rehabilitation of patients.

        • 1
      • Research and Application of Automatic Design System for Seismic Support and Hanger

        张学辉, 杨搏涛, 李鹏阳, 安军海

        Abstract:

        Large-scale projects include complex pipeline systems, seismic supports and hangers have the functions of bearing loads and restraining displacements on the pipelines. However, how to design it correctly and reasonably has many problems in actual engineering, It often becomes the bottleneck of engineering design. At present, the layout and force check of seismic supports and hangers are mainly done manually, which is low in automation and has serious impacts. project progress. To solve this problem, this article takes the actual engineering project as an example, through the establishment of a standard support and hanger family, using the .NET Framework as the framework, using C#, Redevelopment of Revit, through the analysis of the object structure of the API, Explored the interaction method with Revit, Realize the automatic generation of parameterized constraints and automatic force checking, And show the layout in three dimensions.The results show that the research determines the layout design plan of the seismic support and hanger for the engineer, It has brought great convenience in terms of improving work efficiency and timely revising the plan.

        • 1
      • Discussion on checking calculation method of basket type steel cantilever scaffold under special working conditions

        耿大将, 苗恩新, 柏志诚, 金学胜

        Abstract:

        The basket type steel cantilever scaffold has been used in practical engineering, but there is no recognized effective design method at present. There are various special working conditions in the field construction process, so it is necessary to design and check the special working conditions to ensure the construction safety. In order to better guide the engineering practice, the internal force expressions of the main beam and tie rod of the basket type steel cantilever scaffold under general working conditions are obtained by using the theoretical analysis method. On this basis, combined with the actual situation of the site, the checking calculation methods for various special working conditions are clarified. Finally, the calculation examples under various special working conditions are given by using the single factor variable method, and the actual design and construction suggestions are given in combination with the calculation results and field construction practice. The research results show that the node offset on the tie rod, the failure of the tie rod, the increase of the vertical force transmitted by the upright rod and the retraction of the building structure will have an adverse impact on the stress of the scaffold, which needs to be avoided by corresponding design measures or construction management measures.

        • 1
      • Influence analysis of excavation and dewatering of foundation pit with horizontal waterproof curtain on surrounding environment

        钱林根, 李鹏举, 谢致清, 侯长领, 陈 甦

        Abstract:

        In order to analyze the influence and law of the permeability of the horizontal waterproof curtain on groundwater level, settlement of ground surface and adjacent high-speed rail viaduct, use three-dimensional finite element software to first simulate the dewatering and excavation process of the foundation pit in a fully enclosed state, and compare the calculated and measured results; The results show that: (1) the settlement of surrounding ground surface and high-speed rail viaduct piers gradually increase with the process of the excavation and dewatering, and the stimulated results are in good agreement with the measured results; (2) the effectiveness of waterproof system has a great influence on the settlement of surrounding ground and adjacent high-speed rail viaduct piers caused by the dewatering and excavation of the foundation pit. When the permeability coefficient (k) of horizontal waterproof curtain is 1×10-7cm/s and 6×10-3cm/s, the maximum settlements of the surrounding ground surface and the viaduct pier are 63.21 mm, 178.66 mm and 1.04 mm, 31.88mm, respectively; (3) the fully enclosed waterproof system effectively controls the settlement of the adjacent high-speed rail viaduct caused by excavation and dewatering of the foundation pit within the required range.

        • 1
      • Analysis of Deformation Behavior Caused by Tunnel Shield Construction Side-crossing Adjacent Earth-Rock Dam of Reservoir

        余杰, 李怡玮, 程钰博, 俪纲, 孙阳

        Abstract:

        In order to study the safety of tunnel project side-crossing adjacent dam, a finite element model of Nanjing-Jurong intercity rail transit side-crossing Tangquan Reservoir is established. The deformation law of the soil around the tunnel and the rockfill dam during shield construction is analyzed by using finite element software, and the influence of different reservoir water level conditions on dam crest displacement caused by tunnel construction is studied. The results show that the vertical displacement of soil around the shield machine presents a "W" distribution during construction, and the surface uplift and subsidence meet the limit requirements of the engineering specification. According to the deformation of the earth-rock dam, the vertical displacement of the dam is much greater than the horizontal displacement, and mainly appears on the back water surface. As the distance between excavation location and the dam becoming closer, the largest vertical displacement is observed to continuously move upward to the dam crest and gradually has an impact on the deeper part of the dam. To ensure structural safety, the shield construction should be carried out under a relatively low and stable water level. The research results can provide reference for building structure safety assessment with high deformation control requirements and the engineering construction during tunneling.

        • 1
      • Fast Random Neighbor Discovery algorithm based on wireless Ad hoc network of directional antennas

        刘成朋, 杨健

        Abstract:

        Abstract: In order to reduce the time required for wireless Ad hoc network and improve the probability of random discovery algorithm for neighbor discovery, a fast random neighbor discovery algorithm based on directional antennas wireless Ad hoc network is proposed. The proposed algorithm is based on the characteristics of the phased array antenna to freely switch wide and narrow beams, gives full play to the advantages of strong wide beam search ability and narrow beam transmission ability, using wide beam and narrow beam for neighbor discovery, and combining the collision retransmission mechanism and neighbor node auxiliary discovery mechanism, the optimal competition window value of the collision retransmission is calculated, which reduces the time cost of the neighbor rediscovery, increases the discovery probability of the neighbors and meets the needs of fast networking and high-speed communication. Simulation experiments show that under different numbers of nodes, the number of time slots required for neighbor discovery of the proposed algorithm is less than that of the random discovery algorithm based on collision avoidance, and it has a faster neighbor discovery speed. The results can provide an efficient neighbor discovery scheme for wireless ad hoc network and improve the performance of wireless self-organized network.

        • 1
      • Research on hierarchical beamforming algorithm for large-scale area array

        刘潇, 刘宝蕊, 窦修全, 陈卫东

        Abstract:

        In order to solve the problem of complex implementation of large-scale array broadband digital beamforming system, combined with the phase insensitive characteristic of beamforming in subarrays, a hierarchical beamforming algorithm based on subarrays is designed. First, determine the size of the sub-array according to the information parameters such as the array synthesis bandwidth, frequency band, and array size. Use a phase shifter to perform phase shift processing in the sub-array to achieve narrow-band analog beam synthesis. Secondly, use FIR filters between the sub-arrays to perform the broadband signal The precise control of the time delay realizes broadband digital beam synthesis, thereby completing the adjustment of the beam synthesis error in the sub-array, and finally performs a simulation test on the large-scale area array hierarchical beamforming algorithm. The design results show that the sub-array-based hierarchical beamforming algorithm can achieve the required beam performance indicators, and at the same time can effectively reduce the implementation complexity of the large-scale area array broadband digital beamforming system. The designed sub-array-based hierarchical beamforming algorithm can be applied to large-scale phased array beamforming, which has certain reference value for engineering realization.

        • 1
      • Waveform gengeration technoloy of communication signal based on DRAGAN

        张君毅, 陈丽, 刘芳

        Abstract:

        In order to solve the problem that it is difficult to reconstruct complex signals with specific frame structure of non partners, a method of generating signals by Deep Regret Analytic Generative Adversarial Networks (Dragan) is designed. Dragan can learn the potential distribution of target data on the premise that the characteristics of target signal are unknown. Firstly, by inputting the sample signal and signal generated by the generator into the discriminator and using the loss function of Dragan for conditional constraints, the discriminator will distinguish whether the signal comes from the generated signal or the sample signal, and the generator will try to generate a signal similar to the characteristics of the target signal to deceive the discriminator. The simulation results show that when the signal-to-noise ratio is 9dB or above, the generated signal not only learns the modulation style, symbol rate and frequency bandwidth of the sample signal, but also accurately restores the symbol information of a specific frame. Compared with the traditional methods, the signal generated by Dragan has the characteristics of high correlation, simple reconstruction process and strong generalization ability. The designed network model has practical value in the construction of electromagnetic environment and other scenes.

        • 1
      • Research on space data distribution technology based on blockchain

        卢天, 徐小刚, 王士成, 李峰, 文义红

        Abstract:

        In order to distribute massive space data quickly, accurately, safely and reliably, the space data distribution technology based on blockchain is carried out. First, the deficiencies of traditional space data distribution services are summarized, and the advantages of applying blockchain technology to space data distribution and the key and difficult difficulties that may be encountered in the application process are analyzed. Second, the design scheme of space data distribution based on blockchain is proposed in general. Finally, through simulation experiments, the advantages of the application of the blockchain in the space data distribution system and the impact on the original distribution system after being connected to the blockchain are tested contrapuntally. The research results show that the connect of blockchain can contribute to the trusted sharing, traceability and immutability of space data, and has little impact on the synchronization time of the resource view of the original space data distribution system, which can provide a new idea for the current aerospace data distribution service field.

        • 1
      • A design method of frequency hopping communication interference detection threshold based on FCME algorithm

        潘申富

        Abstract:

        Frequency hopping satellite communication is an important part of military communication. It faces the threat of malicious interference in application. Therefore, it is necessary to detect the interference of the received signal. The threshold design method of detection is the key part of detection. The wideband energy detection model is used to model the received signal, and the probability distribution of detection statistics is analyzed. The method of directly setting the average threshold approaches 50% of the false alarm probability when there is no interference. Therefore, on the basis of FCME algorithm and CFAR threshold setting method, the relationship between some samples and the population under Gaussian distribution is analyzed by using probability statistical knowledge, and iterative correction is added to estimate the noise bottom to set the threshold that meets the requirements of CFAR probability. Theoretical and simulation analysis show that compared with the existing methods, the iterative modified threshold design method based on FCME can obtain the threshold that meets the requirements of false alarm probability under the condition of SNR = 0dB and no interference. When there is partial band interference, the performance of the algorithm decreases, but the obtained threshold can still meet the requirements of false alarm probability.

        • 1
      • Video saliency detection based on pixel-level estimation

        李春华, 郝娜娜, 刘玉坤, 白玉华

        Abstract:

        In order to accurately extract the saliency from videos with complex background, the mapping generated by the motion of objects in the video and the super-pixel level saliency estimation are combined to detect the saliency target in the video. Firstly, the video frame is segmented by super-pixel, and the motion saliency map is generated by combining the intra-frame color, boundary information and the optical flow gradient of inter-frame motion variation. This method has sufficient robustness to extract the foreground objects with various motion patterns and complex appearance scenes. Then, considering the details and regional features of the video frame, the pixel-level saliency map is formed by using the background and foreground saliency estimation of the super-pixel. These cues enhance the refinement of saliency. Finally, the motion saliency map and the pixel level saliency map are dynamically fused by spatiotemporal consistency. The experimental results on public datasets SegTrack-V2 and DAVIS show that the F-measure values in SegTrack-V2 and DAVIS databases are 0.631 and 0.679, respectively. The accuracy-recall rate curve of the algorithm is higher than that of the traditional classical algorithm in complex image databases, which effectively reduces the influence of camera motion, background motion and mutation on video saliency detection.

        • 1
      • Joint application of CFG pile + foam concrete to bridge bump at soft foundation

        卢兰萍, 张宇超, 李明勋

        Abstract:

        In view of the problem of bumping at the bridge head of soft foundation, it is proposed that CFG pile composite foundation should be set up in soft foundation of Luqiao transition section, and foam concrete will be replaced by backfill area in the back of the platform to alleviate differential settlement in the transition section of Luqiao. Based on the actual project case, the optimal CFG pile design is designed, and the finite element software Midas GTS/NX is used to establish the model to ensure the pile parameters unchanged, and simulate the settlement law of the ordinary roadbed backfill and foam concrete replacement. The numerical simulation results show that the CFG pile composite foundation and foam concrete treatment of soft foundation Luqiao transition section can effectively alleviate the problem of "bridgehead jumping", which is of great application value to similar engineering applications.

        • 1
      • Network delay prediction algorithm based on WOA-LSTM for narrowband communication networks

        苏鹏飞, 徐松毅, 于晓磊

        Abstract:

        Narrowband communication network network channel is mainly composed of tropospheric scatter and meteor trail, affected by meteorological factors change, the narrowband network show some time-varying characteristic of network time delay, according to the characteristics of narrowband communication network network time delay stochastic time-varying nonlinear, this paper proposes a optimization algorithm based on whales (WOA) and short - and long-term memory neural network (LSTM) prediction algorithm. The measured data samples are normalized, and the reciprocal of the root mean square error function of LSTM neural network algorithm is used as the fitness function. Whale optimization algorithm was used to optimize the number of neurons in hidden layer of learning rate and the maximum training times of LSTM neural network, and the output of the global optimal solution was used as the initial parameters of LSTM neural network to predict the training of samples. Simulation results show that the accuracy of the prediction algorithm is improved effectively.

        • 1
      • Establishment and application of holographic management system for the abnormal situation of oil and gas station

        刘 朋, 李柏林, 杨全疆, 黄春剑, 孙元疆

        Abstract:

        To fully guarantee the safety of personnel and equipment in the gas gathering processing station, and improve the intelligence level of the oil and gas station, this paper designs and implements a holographic control system for the abnormal situation of the oil and gas station based on informatization and Internet of Things technology. The system establishes a risk identification management and control mechanism based on process safety management and integrity management technology. Through the construction of multiple functional modules such as condition monitoring, fire and gas monitoring, corrosion monitoring, displacement monitoring, process monitoring, and video monitoring, the equipment status, abnormal alarm and early warning of personnel status, production process, and environmental status. The system combines three-dimensional holographic technology to establish a full-scene three-dimensional holographic digital field station, which can dynamically display the position of personnel in the field and the change of equipment status information, and realize the three-dimensional visual management of the station. The system is applied to a gas gathering treatment station, which improves the intelligence level and intrinsic safety of the gas gathering treatment station. The functional framework and key technologies of the system also provide an important reference for the establishment of anomaly management systems in the petrochemical industry.

        • 1
      • Fault pattern recognition of generator based on sparrow optimization-SVM for temperature analysis

        路建, 李 勇, 王宗收, 郝崇清

        Abstract:

        To improve the stability and reliability of the pumped storage power plant system operation, a method for constructing a fault diagnosis model of the generator based on the generator’s tile temperature information at the main station is proposed. This method uses temperature value as feature quantities to construct a support vector machine(SVM) fault diagnosis model. Taking advantage of the free switching between the global optimization and the local optimization of the Sparrow algorithm, the penalty factor and the kernel function parameter combination of the support vector machine are optimized to improve the accuracy of fault recognition. The feasibility and effectiveness of the method proposed in this paper are verified by the measured data under the failure of the smaller gap between the lower guide bearing segment, insufficient capacity of the cooler, the turbine oil ageing, and the mixing of impurities in the Zhanghewan Pumped Storage Power Station.

        • 1
      • Effect of AZ91D powder particle size distribution on the smoke and dust and mechanical properties in selective laser melting process

        王金业, 常志鹏, 岳彦芳, 常宏杰, 杨光

        Abstract:

        Aiming at the problem of generating smoke existed in selective laser melting (SLM) process of AZ91D magnesium alloy powder, different specifications powder were sieved and mixed together in definite proportion to carry out the SLM experiments, which were to study the influence law of the powder particle size distribution on the generation of the smoke in its SLM processing, and find out the optimal powder particle size distribution with less smoke under the condition of ensuring the AZ91D magnesium with higher tensile strength. The SLM experimental results showed that:AZ91D powder particle size distribution had evident effect on the generation of the smoke in SLM process; when forming the same magnesium alloy specimens, the fine powder particle size below 20μm had a obvious effect on the generation of the smoke, and increasing the proportion of large-size powder appropriately could effectively reduce the smoke. Meanwhile, the tensile strength of the magnesium alloy specimens were increased by 6% after removing the powder particle size below 20μm, and increasing the proportion of large-size powder could somewhat reduce the tensile strength of the AZ91D magnesium alloy specimens, but this effect was not obvious. The optimal distribution interval of the powder particle obtained in this study provided a basement for further research on reducing the smoke in SLM process and gaining the high-performance magnesium alloy parts.

        • 1
      • An analog pre-distortion linearizer for GaN power amplifier with temperature compensation

        李飞锐

        Abstract:

        In order to improve the nonlinear distortion of GaN solid-state power amplifier,a new linearizer is developed by using analog predistortion linearization technology . The nonlinear characteristics of diode are enhanced by using multi transistor cascade, and the diode socket circuit is improved and optimized to increase the adjustment range of predistortion curve;The linearizer is used to improve the linear drive module of GaN solid state power amplifier and add the temperature compensation scheme. The linearizer is simulated by electromagnetic simulation software, and the simulation results are good, and the compensation range of gain amplitude can be 0.9dB-7.6dB and the phase compensation range is 9 ° ~40 °. Compared with the relevant literature,it is improved by 1.2dB and 12°respectively.The linear drive module has been applied to the target GaN solid state power amplifier, the saturated power fallback is 7dB at 29GHz,and the third order intermodulation is improved by 7.07dB. The designed predistorter can improve the linear characteristics of power amplifier and improve the performance of satellite communication system, which is of great significance to satellite communication system.

        • 1
      • Research on Communication and Navigation Fusion System Based on Integrated Representation Formula

        彭欢, 何健, 尹继凯

        Abstract:

        In order to interpret the principles of communication and navigation fusion from the basic theoretical level, and provide guidance and theoretical support for the research of communication and navigation fusion, starting from the theoretical basis and representative formulas of radio propagation, comprehensively considering the two core elements of transmission and measurement, deriving the integration of communication and navigation The three unified representation formulas of integrated likelihood probability, channel capacity, and network capacity; based on this, the integrated waveform of communication and navigation is selected and the integrated receiver architecture is designed specifically; an integrated system architecture and resource management solution are provided The realization of the integrated system from two perspectives finally builds a three-level communication and navigation fusion system consisting of an integrated representation formula, an integrated link design, and an integrated system. The results show that the system realizes the integration of communication and navigation at three levels: mathematical mechanism, physical bearing, and application realization, depicts the development framework of communication and navigation integration, and covers the main areas of communication and navigation integration research. It can provide reference and support for the research of signal system, interactive protocol, hardware design and other aspects involved in the development of communication and navigation integration.

        • 1
      • Research on routing protocol of ad hoc network based on multiple transmission methods

        张晓东, 韩卫占, 张 平

        Abstract:

        In response to the comprehensive networking requirements of microwave, radio, satellite and other multi-means, this paper proposes an OLSR routing protocol based on node MPR (N-OLSR) to realize the global sharing and optimized use of multi-means communication resources. By shifting the OLSR"s mechanism of selecting MPR on the interface to the node-based MPR, it is possible to reduce the repeated election of MPR in the context of multiple communication means of nodes. Due to the existence of multiple communication means, different bandwidths will exist in heterogeneous subnets. Therefore, the interface index is used to replace the interface IP address. Different index numbers represent different bandwidths to further optimize the MPR election. Reduce routing protocol interaction overhead. The results of simulation experiments show that the improved routing protocol can reduce routing overhead and speed up network convergence, providing a reliable routing protocol scheme for ad hoc networks with multiple transmission methods.

        • 1
      • Research on simulation technology of control system based on peacekeeping training

        赵建, 李宝莲, 岳云鹤, 刘晶

        Abstract:

        The research on simulation technology of control system based on peacekeeping training was developed in order to solve the long-standing problems in the United Nations peacekeeping operations,such as the basic training environment in China is difficult to be realistic, the implementation of mission standards is not skilled, and the emergency response is not in place.This paper studies the use of virtual reality, modeling and simulation, immersive experience, artificial intelligence and other advanced technologies to build virtual battle filed environment,realize effective positioning and attitude acquisition of large space and support for confrontation simulation flexibly.The results show that it can help soldiers have realistic experiences in advance, standardize implementation standards, simulate red-blue against.In particular,the research of large space position technology can effectively extend the virtual battle field environment,significantly improve the effect of joint training,save training funds,avod training accidents and improve the training pertinence.

        • 1
      • Design of stroke treatment and remote monitoring system

        张雪芹, 叶志明, 孟凡利, 刘华波

        Abstract:

        In order to meet the needs of home-based rehabilitation treatment and recurrence Pre-warning monitoring of discharged stroke patients, the home-based stroke treatment and remote monitoring system integrating treatment, human physiological signal acquisition and data analysis, Pre-warning and other functions is designed. Firstly, the therapeutic instrument is designed based on transcranial direct current stimulation technology to output constant and accurate direct current. Secondly, the smart bracelet is developed as an auxiliary monitoring device to record the patient's heart rate and other data in real time and sends the data to the mobile APP through Bluetooth. Finally, the treatment records and vital signs data of patients are uploaded to the cloud database through mobile APP for further analysis, which is used to adjust the treatment plan or Pre-warning of stroke recurrence. The design results show that the system not only meets the needs of rehabilitation treatment of stroke patients, but also the stimulation current control accuracy index of the therapeutic instrument is better than that of foreign equipment. At the same time, the interconnection between cloud and equipment is realized, which has important practical significance in the home treatment of stroke patients.

        • 1
      • Store sales forecast based on stacking model fusion

        曹丽惠, 阮冬茹

        Abstract:

        Sales forecast in modern enterprises is the core link of goods supply. It is essential for reasonable control of production costs, arranging the production plan of goods, and adjusting the inventory of goods. It is an important reference for marketing, logistics, production and other links. In order to effectively use the historical sales data of enterprise stores and provide data support for enterprise decision-making, based on the Stacking model fusion algorithm, RF(Random Forest), SVR(Support Vector Regression), ARIMA(Autoregressive Integrated Moving Average), LGBM(Light Gradient Boosting Machine), GRU (Gated Recurrent Unit) five single models are primary learners, CART (Classification And Regression Tree) Is a fusion model of secondary learners, which predicts the product sales of enterprise stores. The experimental results show that the model fused with the Stacking model is compared with the LGBM model with the best effect in the single model. The RMSE (root mean square error) is smaller, the MAE (mean absolute error) is smaller, and the R2 (coefficient of determination) value is larger, indicating that the prediction accuracy of the Stacking fusion model is higher, and it has a certain practical reference value for corporate decision-making.

        • 1
      • NIR Phosphorescence Turn-on Aptasensor for Determination of 17 β - Estradiol

        史学丽, 高辉, 周永红, 张毅, 赵伟

        Abstract:

        The sensing was based on the inhibition of fluorescence resonance energy transfer (FRET) between an aptamer conjugated NIR persistent luminescence nanoparticle (PLNP) and molybdenum disulfide (MoS2) nanosheets by the target 17β-estradiol. The sensitivity, accuracy and linear range of the phosphorescent sensor were investigated by measuring Ph, incubation time and MOS2 concentration. Using this approach, 17β-estradiol concentrations from 0.5 ng·mL-1 to 1.2μg·mL-1 were quantified from 0.5 mL samples. Within-run and total imprecision ranged from 5.9% to 12.1%, respectively. Selectivity is comparable to a traditional (High-performance liquid chromatography or GC) benchmark in quantitative results. In addition, 20 minutes of UV extraction and 30 minutes of camera obscura preservation were saved by collecting near-infrared phosphorescent signal immediately after the reaction of Aptamer and target. Finally, the operating procedure and signal intensity were improved without the interference of fluorescence of milk matrix and its analogues, and the system showed a significant selectivity for 17β-estradiol analogues. Our system exhibited remarkable selectivity toward 17β-estradiol over several analogues and was applicable in complicated food samples such as diluted milk .

        • 1
      • Research on development Countermeasures of Clothing Live Broadcast Marketing based on consumer perception

        黎锋, 刘雅玲

        Abstract:

        With the rapid development of live broadcast marketing in recent years, live broadcast marketing has further become the new favorite of major clothing brands during the epidemic period. However, while the major clothing brands are conducting live broadcast marketing, various problems are gradually exposed, such as: unprofessional anchors, incorrect goods of clothing products, different goods of the same style, poor interactivity, single live broadcast form, low user stickiness, lack of after-sales service and other problems. This paper will make an in-depth analysis of the problems such as low user stickiness and poor experience in the operation process of clothing live broadcast marketing through questionnaire survey, based on consumer perception and combined with relevant literature. In this paper, the optimization strategy of clothing live broadcast marketing will be proposed from the three aspects of clothing merchants, live broadcast platform and consumers, aiming to provide consumers with a more professional, interesting and quality-assured clothing live broadcast marketing experience service, promote the further development of the clothing industry, and achieve a win-win situation for consumers and merchants.

        • 1
      • Automatic vehicle path tracking control based on model predictive contouring control

        潘公宇, 刘一

        Abstract:

        Based on model predictive contouring control, a curve path tracking control strategy is proposed for driverless car curve and obstacle avoidance scenarios. Firstly,Sthe two degree of freedom single vehicle model and the Pacejka tire model together to build the vehicle model, and then follow the contour control combines the vehicle model, path planning and tracking problem for a nonlinear optimization problem, linear time-varying model, are obtained by linearized at each sampling time in the form of a convex quadratic programming in establishing local approximation of nonlinear optimization problem. Meanwhile, In order to keep the vehicle stable while following the path, the stability constraint is applied in combination with the vehicle stability envelope. Moreover, by applying lane boundary constraint, the obstacle avoidance function of the autonomous driving vehicle is realized. Finally, MATLAB/ Simulink and CarSim are combined to carry out the co-simulation, which shows the effectiveness of the proposed path tracking strategy.

        • 1
      • The law of diffusion and migration of oil spilled from submarine pipelines under wave action

        王驰, 梁法春, 何振楠, 赵峰辉, 王梦琦

        Abstract:

        In order to solve the serious environmental pollution and economic losses caused by the oil spill accident of the underwater oil and gas pipeline and to better meet the actual needs of the project, in view of the large calculation error caused by the current model without considering the wave conditions, a two-dimensional windy model with waves was established using fluid mechanics software to predict the oil spill process. The simulation results were compared with Fan's experimental values to verify the reliability of the model. The model was based on the VOF(volume of fluid ) method , combined with the SST k-ω turbulence equation and PISO algorithm, to study the effects of density, wave length, and wind speed on oil spills. The research results show that densityl significantly affects the time to sea level and the lateral drift distance of oil spill. The wave length has a slight effect on the ascent speed of oil spill, mainly affecting the lateral spread. The wind speed has almost no effect on the process before the oil spill reaches sea level but accelerates the spreading process after arrival.The research results can provide a reliable basis for the formulation of oil spill accident treatment plans and oil spill recovery and utilization.

        • 1
      • Ownership structure and effectiveness of internal control——A case study of listed companies in the real estate industry

        曹慧, 张婧

        Abstract:

        As economic globalization brings huge economic opportunities to enterprises, it also brings unprecedented competitive pressure, and higher effectiveness of internal control can enhance the core competitiveness of enterprises. The case study can more truly describe the situation of the case, and effectively provide easy-to-understand explanations for other similar cases. Meanwhile, the conclusions obtained also provide reliable reference basis for other similar cases. Therefore, through the case study of five listed real estate companies, this paper discusses the influence of the equity structure and the nature of checks and balance shareholders on the effectiveness of internal control from the horizontal and vertical aspects, and draws a conclusion: the effectiveness of the company's internal control with equity checks and balance is better than that of a single dominant company; When there are state-owned checks and balance shareholders, compared with state-owned companies, non-state-owned companies have better internal control quality. When the checks and balance shareholders are non-state-owned, the company's internal control is more effective.

        • 1
      • Design of panel forming device for purification partition board

        张嘉钰

        Abstract:

        Aiming at the problems of semi-automatic production of panel forming in the production process of purification partition board, such as low efficiency, high dependence on production workers' skills, and difficulty in quality and loss control, a full-automatic panel forming device is designed, which realizes the automatic forming of panel by using the feeding mechanism, leveling mechanism, punching mechanism, forming mechanism and cutting bending mechanism. It greatly improves the forming efficiency, forming quality and reduces the labor intensity of workers. The design of the device conforms to the development trend of automatic and unmanned purification partition board production, and has high market value.

        • 1
      • Design of Robot for Automatic Oiling of Air Conditioning Connecting Rod

        朱金达, 刘庆磊, 邓飞, 牛虎利, 高思齐, 刘兆奂

        Abstract:

        In order to solve the problems of existing air conditioning connecting rod oiling, such as over coating, less coating, missing coating, uneven painting, low efficiency and high cost, an automatic oiling robot for air conditioning connecting rod is designed. Based on the idea of three-axis design and precise positioning, the overall design scheme of gantry type three-axis oiling structure and mold box auxiliary positioning is proposed. The control system adopts Siemens S7-200 smart, designs PLC hardware wiring diagram, uses EM253 position control module to control stepping motor, and combines sensor and touch screen human-computer interaction interface to realize automatic oiler control. The motion simulation analysis of air conditioning connecting rod automatic oiling process is carried out with UG. The results show that the robot greatly improves the efficiency of oiling and reduces the labor intensity of workers; the efficiency of automatic oiling is about 4.83 times of that of manual oiling; the equipment has the advantages of strong stability, simple structure and high degree of automation, which conforms to the development trend of automation, and provides a new solution for oiling other small parts.

        • 1
      • Analysis of axis offset of clamped rebar

        牛虎利, 郑祖威, 王渊, 张嘉钰

        Abstract:

        Rebar belongs to irregular workpieces, and the deviation of rebar axis in the clamping process will eventually lead to machining errors. This paper analyzes the causes of axis offset when two - jaw chuck and three - jaw chuck are clamped on the workpiece. The mathematical model of the deviation of the rebar axis when the rebar is clamped with two claw synchronous chucks and three claw chucks is established. The mathematical model was solved by MATLAB, and the variation range of the deviation value of the rebar axis when the v-block Angle was 60°, 90° and 120° respectively when the two-jaw synchronous chuck clamped the rebar and the deviation value of the rebar axis when the three-jaw chuck clamped the rebar was obtained. The results show that, compared with the other two kinds of two-jaw synchronous chucks with v-block Angle of 90°, the deviation range of the rebar axis during clamping is the smallest, ranging from 0 to 1.59mm. When the three-jaw chucks are clamping the rebar, the deviation range of the rebar axis is 0.14-1.34mm.

        • 1
      • An improved detecting algorithm of weak signals based on polarization-sensitive array

        徐少波, 张丹, 宋肖, 李新亮, 张明程

        Abstract:

        Aiming at the problem that the Global Navigation Satellite System (GNSS) is confronted with great challenges in terms of continuity, integrity and usability due to the complex electromagnetic environment, an improved signal detecting algorithm of weak interference based on polarization-sensitive array was proposed. Through the joint-processing in space, frequency and polarization domain of the real-time data received from antenna elements and the descending processing of the eigenvalues in each frequency bin, the distribution curve of eigenvalues in whole frequency domain can effectively separate and identify the weak signals. And even the realization power and computational complexity were reduced through the improved MDL criterion based on multistage wiener filter, as the step of eigen-decomposition was omitted. Simulation results demonstrate the efficiency and validity of the proposed method, and the detecting results still keep highly effective even with amplitude and phase errors, thereby it has high engineering practice value.

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      Display Method:: |
      Volume 39,2022 Issue 4
        Special Column on Pollution Prevention and Control
      • YANG Lili, FENG Yuan, ZHOU Jingbo, HE Linyan

        2015,32(1):85-89, DOI: 10.7535/hbgykj.2015yx01015 

        Abstract:

        In order to analyze haze change regularity and the origin of the haze weather and provide technical support for its prevention, the correlation between the haze and meteorological condition and pollutants concentration are discussed based on the surface meteorological observation data and the pollutants concentration monitoring data from the step station of Shijiazhuang environmental monitoring center. It is proved that the haze days during the 1960s is minimal; the haze days rises sharply during the initial stages for reform and opening-up and the 1990s; the haze days obviously decreases after the 2000s.The haze occurs more frequently in autumn (20.5%) and winter (53.5%), and less in spring(15.2%) and summer(10.8%). Quiet wind, lower humidity and continuous no-rain days are the important causes of the haze. The mass concentration change regularity of SO2, NO<i>x, PM2.5 and PM10 (the correlation coefficients are 78.4%,70.9%,77.3% and 73.8%, respectively) is coherence with the haze days of Shijiazhuang City. Their mass concentration is obviously higher in haze days than in the normal days. Their mass concentration is highest in winter, lower in autumn and lowest in summer.

      • DU Jia-ying, SHANG Hui-jian, XU Bao-yun, ZHENG Xue-ming

        2005,22(1):52-54, DOI: 10.7535/hbgykj.2005yx01016

        Abstract:

        Po lyv inyl Alcoho l ( PVA) is w ater??soluble polymer , and no n??t ox ic t o human body. It has go od bio??compat ibility, so PVA develops rapidly in medical t reatment . Develo pment in the study o f PVA, including adv ance of PVA hydro??gel in eye, wo und dr essing s and art ificial car tilag e, and application o f PVA member in medicine and so o n are intro duced in det ail in t he re?? v iew

      • 综述与述评
      • CHANG Hong-fei, YANG Zhen

        2008,25(4):262-269, DOI: 10.7535/hbgykj.2008yx04022

        Abstract:

        To provide a foundation for further study on Huanglianwendan decoction and its possible clinical applications,this paper reviewed the recent 10years'' literatures about its clinical studies, including those on treating psychosis, digestive system disease, decompensation disease, chronic renal failure disease, curdiovascular, and otorhinolaryngology disease.

      • YANG Li-yan, SHANG Hui-jian, WANG Liang, ZHENG Xue-ming

        2010,27(3):210-212, DOI: 10.7535/hbgykj.2010yx03017

        Abstract:

        This paper introduced the widespread use of acetonitrile as a good organic solvent and an important raw material in the field of chemical industry, medicine and so on, and gave a summary report about some direct and indirect synthesis methods in regard of the properties of acetonitrile. Then the potential application prospect and synthetic method of acetonitrile were put forward.

      • Research and Development
      • YIN Xin, ZHANG Jianrong, XU Guodong, WANG Haiwen

        2015,32(1):1-7, DOI: 10.7535/hbgykj.2015yx01001 

        Abstract:

        Antimony-doped tin dioxide is an excellent catalyst, which has good electrical conductivity and high temperature stability. The sol-gel method is used to prepare ATO nanopowders, and their structure characterization and performance analysis are also conducted. Stable tin and antimony citrate complexes solution is obtained from the starting materials metal tin and antimony trioxide. The solution undergoes sol-gel transformtion when acetonitrile is added dropwise. Antimony doped tin oxide nanoparticles are obtained with the washed gel heat-treated at different temperatures. The antimony doped tin oxide nanoparticles exhibit shrinking crystallite size, increasing specific surface area and tin oxide lattice parameters changing with the rise of antimony doping content. The crystalline size increases, while speciflc surface area decreases with the increase of annealing temperature. The particle crystallinity shows a decrease tendency for the high antimony doping level with increasing temperatures.

      • 综述与述评
      • BIAN Wei, WANG Lu-guang, LI Hong-bo

        2009,26(3):195-199, DOI: 10.7535/hbgykj.2009yx03018

        Abstract:

        This article summarized the physical chemistry and biological treatment technologies of high salinity organic wastewater and introduced combined processes of biological and other treatments. Halophilic bacteria and salt-tolerant microzyme have wide practicability in the treatment of highsalinity wastewater.

      • HU Shi-hai

        2009,26(1):58-60,64, DOI: 10.7535/hbgykj.2009yx01016

        Abstract:

        This paper introduced the production process and application of pentaerythritol and analyzed its market situation.Then the paper pointed out the problems unsettled and gave some advices.

      • SHANG Qing, ZHENG He-tang, YAN Li, SHI Yong-li

        2005,22(1):38-43, DOI: 10.7535/hbgykj.2005yx01013

        Abstract:

        Po lymer nano par ticles as drug car rier sy st ems is a new kind o f drug deliver y sy stem. It is easy to get to site- specific throug h bio film bar rier fo r the nanoparticles. Po lymer nanopart icles hav e new characterist ics fo r multifo rmity of polymeric mater ial, so po lymer nano par ticles em ployed as drug carr iers hav e att racted attention. In this r ev iew , the tw o prepa rativ e methods for dispersio n of the pr eformed po lymer s and polymerization o f mo nomers are ex pounded, t he measur ing metho d of particles d-i ameter , modality, moleculer w eight, Zeta po tent ial and thermic perfo rmance are investig ated, and the applicatio ns are discussed. At last are the sug g estions o n development t rend fo r polymer nanoparticles as drug car rier

      • YU Xue-yin, CAO Tuo-huang, CHEN Ben-sheng

        2009,26(5):428-430,433, DOI: 10.7535/hbgykj.2009yx05017

        Abstract:

        Face recognition is a technique used for identify identity by analyzing face images and distilling effective recognition information from face images. This article presented an arithmetic of face recognition based on eigenfaces, gave the explaination of eigenface,and made a simulation of DRL face database by using program baced on OpenCV. This method recognizes and classifies face images by computing the space distance between face image and eigenfaces,and it can recognize face image quickly and exactly.

      • 应用技术
      • DOU Hong, ZHANG Xiao-xin, GAO Chun-ping

        2009,26(2):90-94, DOI: 10.7535/hbgykj.2009yx02006

        Abstract:

        This paper investigated the feasibility of detecting Sudan Red in foods with thin layer chromatography, and compared the result of Sudan Red separation with high-effect silica gel G plates (HPSGG) and the result of it with polyamide plates. It is found that HPSGG has more advantages over polyamide plates in separating Sudan Red. HPSGG gives high detection sensitivity, up to 0.3mg/ kg, fast analysis and clear separation. Polyamide plates needs 40minutes while high-effect silica gel G plates needs only 5~10minutes. The Sudan pigments and other interference pigments such as pepper pigments,can be completely separated. The method can be applied to rapidly detect Sudan Red illegally added in foods such as chilli products and hamburgers.

      • LEI Li-gai, MA Xiao-zhen, WEI Fu-xiang, WANG Zhan-hui

        2011,28(1):72-76, DOI: 10.7535/hbgykj.2011yx01019

        Abstract:

        This paper summarized the methods of the measurement of total nitrogen, the measurement of total phosphorus and the combined measurement.It compared the merits and demerits of these methods and put forward the development trend of the measurement methods.

      • CHENG Zhong-hao

        2005,22(5):281-284,288, DOI: 10.7535/hbgykj.2005yx05011

        Abstract:

        A br ief intro ductio n to DNP3. 0 ( Distr ibuted Netwo rk Pr oto co l 3. 0) is presented at this paper to gether w ith an explanation o f t he architecture and functio nality pr ovided by this prot ocol. An appr oach to implement the pr oto co l that ado pts the OOP and the VCL component techniques in the Delphi prog r amm ing envir onment is discussed

      • 研究与开发
      • XU Bing-wen

        2011,28(5):302-305, DOI: 10.7535/hbgykj.2011yx05006

        Abstract:

        Based on sixsigma,the software process defects management model is established. The model combines the method of six sigma to provide effective solution for software process defects management. The model can get better quality and better customer satisfaction by optimizing the software development process, tracking adverse factors and eliminating defects.

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