bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Device for Studying in Vivo Magnesium Degradation under Controllable Cyclic Load in the Rabbit Model
Authors: Zhang Xuanbin , Hao Zhixiu
Published: April 2023

Magnesium is an important material for medical implants due to its special properties including biocompatibility, low density, high mechanical property, and biodegradability. The in vivo implantation experiment of magnesium is an important experimental method to obtain its degradation characteristics. In recent years, although in vitro studies have found that the degradation of magnesium under cyclic loading is different from static loading, there is the lack of in vivo experiment to verify the above in vitro results, while the degradation characteristic of magnesium under load is an important factor to be considered when magnesium is used as orthopedic implant. We designed a novel device to apply controllable cyclic load onto the magnesium material implanted in the rabbit tibia, containing loading chamber, motor and gear reduction mechanism, and Singlechip Computer, etc. The conducted experiments have shown that the devices were able to apply load onto the implanted magnesium in rabbits in vivo during unrestricted cage activity for at least 16 days. Likewise, no distortion or infections were observed. Results demonstrated that the novel device was able to produce alteration of the mechanical environment in vivo rabbit tibia, which showed that the load device is suitable for in vivo loading degradation characteristics testing of magnesium or magnesium alloys.
Adapt to the Development of Aero-engine Materials and Improve the Level of Trace Sulfur Detection
Authors: Wei Jianhuan , Xu Hui
Published: April 2023

With the development of aero-engine industry, the main materials of aero-engine, such as superalloys and steels, have higher needs for the detection of trace sulfur. We start from four aspects: ultra-pure composite flux, two-stage calibration at both ends, handling of blank influence and application of Carbon and Sulfur determinator to improve the detection level of trace sulfur. The detection of trace sulfur near 1 ppm has achieved ideal result, and the detection technology has reached the world advanced level.
Research on Settlement Control of Rectangular Pipe Jacking Crossing Weak Watery Stratum with Variable Slopes
Authors: Yang Jinchao , Wang Ruijue , Zhang Yuan , Bian Anqi
Published: April 2023

In order to study the influence of construction parameters on settlement when a pipe jacking machine with a rectangular section passes through weak watery stratum with variable slopes, based on the pipe jacking construction project of utility tunnel on Yangtze River Avenue, this paper analyzes the technical data of the pipe jacking machine, which includes changes of jacking force, frontal earth pressure and correction of elevation at different jacking distances, then tries to illustrate the correlation between these operational parameters and soil settlement. The on-site monitoring data of surface settlement on different dates is also be analyzed to evaluate the effect of the controlling countermeasures. Finally, some effective measures and key points are put forward to provide a reference for similar jacking projects in the future.
Study on Interlaminar Fracture Toughness of the CNTs-CF/epoxy Resin Composites
Authors: Zhang Haiyun , Xu Jingli , Zhang Jianqin , An Jing
Published: April 2023

Carbon nanotubes(CNTs) show the characteristics of high modulus and high strength in mechanical properties, and also have good deformation properties. Therefore, when carbon nanotubes are added to the composites, they can bear large stress and greatly absorb energy, so as to increase the durability of the composites. This paper preparaed the CNTs- Carbon fibers(CF)/epoxy resin composite prepreg and the interlaminar fracture toughness of the composites was investigated. The analysis shows that after introducing a samll amount of carbon nanotubes into carbon fiber/ epoxy resin composites, carbon nanotubes can hinder the dislocation movement and crack propagation in the resin matrix(i.e. the area between carbon fibers) to improve the fracture initiation of materials.
Enhanced Cr(VI) Adsorption from Water by Reactivation Treatment of Apricot Shell Activated Carbon
Authors: Lu Chunlan , Zhang Xiaolin
Published: April 2023

The pore structure of apricot shell activated carbon was changed by reactivation treatment. The influence of reactivation treatment of activated carbon on the adsorption of hexavalent chromium [Cr(VI)] from water was investigated under different conditions. The results show that the reactivation treatment enriches the pore structure of activated carbon and increases the pore size. When pH is under 4, the reactivation treatment of activated carbon does not cause a significant difference in the adsorption amount of Cr(VI) compared with untreated activated carbon. However, it is obviously contribute to Cr(VI) adsorption solution when pH is more than 4. In the same adsorption temperature, adsorption time, solution pH, and ratio of activated carbon to Cr(VI), reactivated activated carbon shows higher Cr(VI) adsorption capacity in aqueous solution than the untreated activated carbon, and maximum Cr(VI) removal rate of the reactivated activated carbon reaches 99.83%.
Experimental Study of Bearing Capacity of Steel Frame with Portal Steel Plate Shear Wall Member
Authors: Chen Yuhui , Zheng Xiaoyao , Wang Xintang , Wang Zhanliang
Published: April 2023

The steel frame with portal steel plate shear wall unit presented here is a new steel structure by assembling the portal steel plate shear wall into the steel frame through bolt connection. For study of shear resistance and bearing capacity of the structure, it is necessary to conduct experimental research. Three frame specimens are made here, and two geometric shapes and the case of setting stiffeners and not setting stiffeners are considered respectively. The concentrated lateral load is applied in the test and displacements and strain were measured. The results show that the setting of the shear wall element has an obvious effect on improving the lateral stiffness of the steel frame, and the failure also shows obvious plastic deformation characteristics. It is also seen that the connection has no evident failure or deformation, which means the connection construction is effective.
Control Method for Connecting the Elevated Expressway with the Ground Intersection Based on Reflective Film Material Guidance
Authors: Li Yuqi , Zhan Xuejuan , Liang Zijun , Wang Ruihan , Xiao Yun , Peng Min
Published: April 2023

With the rapid development of elevated expressways, urban elevated expressways bear more and more traffic volume, and the adoption of environmental protection materials has become an inevitable trend in the development of elevated expressways. a control method for connecting the elevated expressway with the ground intersection based on reflective film material is presented. Firstly, the green reflective film material is used to guide the connecting section of the elevated expressway and the ground intersection. Then, the corresponding signal timing method is proposed to optimize the traffic flow time between the elevated expressway and the ground intersection.Finally, through the analysis of the VISSIM traffic simulation software to evaluate the results show that the method is based on the reflective film material can effectively guide the elevated expressway with the ground intersection connection section, under the premise by signal optimization technology to further improve the traffic efficiency, effectively reduces the overhead elevated expressway with the ground intersection connection number of the conflicts, It provides a basis for the research on the connection section between the elevated expressway and the ground intersection based on reflective film material guidance.
Preparation and Characterization of New Phase Change Materials Based on PTLA / PVAc Blends
Authors: Li Dian , Wang Hongyang , Chen Xiao , Wang Shu , Lu Li , Liu Qibin , Wang Pingjuan , Huang Zhonghui , Liu Jialei
Published: April 2023

The role of phase change materials in energy storage and heat regulation has attracted more and more attention in recent years. PTLA, as a new biodegradable polyester polymer material obtained by the copolymerization of lactic acid and propylene carbonate showed us an appropriate phase transition temperature around 10 °C and the large phase transition enthalpy of about 50 J/g. In this manuscript, PTLA and traditional polymer of polyvinyl acetate (PVAc) were used to prepare novel phase transition materials by physical blending. And the blending compounds showed us the phase transition temperature in the range from 0 °C to 30 °C and the phase transition enthalpy in the range from 50 J/g to 78 J/g. Else, the thermal stability and blending compatibility were also studied in details, by Thermogravimetric analysis and scanning electron microscopy respectively.
Identifying Void and Crack Defects in Type III Hydrogen Storage Vessels Based on Microwave Inspection
Authors: Pan Jinping , Zhu Chaoming , Hu Jian , Zhu Xinwei , Yang Jianhua , Guo Yanxing , Tan Lianjiang
Published: April 2023

Microwave technique has become a promising candidate for non-destructive testing. In this study, microwave-based method was used to inspect type III hydrogen storage vessels and to identify void and crack defects in the carbon fiber composite wound layer. Using a vector network analyzer, the reflection coefficient S11 of type III hydrogen storage vessel samples with no defects and with a void or a crack defect in the composite wound layer was measured. The defect-containing vessels had S11 values significantly different from those of vessels without defects, based on which the defects can be detected. Moreover, identification of the two defects can be achieved by comparing the values of S11, as the void results in more microwave reflection than the crack. During the inspection, only when the horn antenna is against the defect does the S11 show great changes, indicating the detection sensitivity of the method. This work provides new insights into inspection of defects in the of carbon fiber composite wound layer of type III hydrogen storage vessels.
Study on Small Fatigue Crack Growth Rate of SLM AlSi10Mg Alloy
Authors: Wang Zhen , Ye Xuan , Li Xide , Liu Xiaoming
Published: April 2023

In this paper, the fatigue small crack growth rate of selective laser melting (SLM) AlSi10Mg alloy is studied by in-situ SEM experiment. The experimental results show that the small crack growth rate of SLM AlSi10Mg alloy can be described by Paris law, and the crack growth rate increases significantly with the increase in temperature. In addition, the combination of finite element simulation and fracture analysis shows that the pore is one of the main factors affecting the dispersion of small crack growth rate.
Experimental Study on Ultrasonic Tomographic Method to Detect Compactness of Concrete filled Steel Tube
Authors: Lu Wanzhu , Shen Yang , Dai Shuang , Shao Zhiwei , Qu Ming , Chen Jianghua
Published: April 2023

When the concrete filled steel tube member is poured, due to the large volume, the internal concrete is difficult to vibrate, easy to produce defects, not easy to observe, and the internal defects will have a non-negligible impact on its mechanical properties, therefore, it is particularly important to detect the internal defects of the concrete filled steel tube column. In this paper, the internal defects of CFST are studied based on the principle that acoustic wave propagates along the shortest acoustic path in CFST. For square concrete-filled steel tubular column, when the measurement method is adopted, the theoretical sound time calculation and sound velocity distribution map imaging are carried out for different measurement point densities. It is found that the defect identification effect is better when the number of measurement points is 5.For circular concrete-filled steel tubular column, when the measurement point spacing is determined to be 30° arc length, the measurement point arrangement method in the specification cannot be combined with CT imaging method, so the measurement point arrangement method of one-point emission and five-point receiving is proposed, and it is found that it has good identification effect on internal defects.
Design and Development of Tissue Engineering Materials based on Imine Bonds
Authors: Tao Yangchun , Liu Siwei
Published: April 2023

Hyaluronic acid was oxidized to obtain hyaluronic acid containing aldehyde groups (ALD-HA). Then it was reacted with PETMP-AU, the photo-initiated reaction product of pentaerythritol tetra(3-mercaptopropionate) and allylurea, to synthesize a bioscaffold material with dual degradation behaviors, both to hyaluronidase and to weakly acidic environment. The material has a heterogeneous porous micromorphology with a pore size ranging from 10 to 100 μm. The growth of osteoblasts in the polymer was observed. The MC3T3-E1 osteoblasts encapsulated in the polymer could adhere to the inner wall of the pores and grow three-dimensionally. Moreover, the cells could continue to divide and proliferate and grow well. It shows that the material has good biocompatibility and can be used for biological tissue engineering materials.
Detection of Void and Crack Defects in Type IV Hydrogen Storage Vessels by Microwave Technique
Authors: Pan Jinping , Zhu Chaoming , Hu Jian , Zhu Xinwei , Yang Jianhua , Guo Yanxing , Tan Lianjiang
Published: April 2023

Non-destructive testing based on microwave technique has been developing rapidly. In the present study, microwave-based method was used to detect void and crack defects in the carbon fiber composite wound layer of type IV hydrogen storage vessels. Taking advantage of a vector network analyzer, the reflection coefficient S11 of type IV hydrogen storage vessel samples without defects and with a void or a crack defect in the composite wound layer was measured. The defect-containing vessels exhibited S11 values much different from those of vessels without defects, according to which the defects can be detected. Additionally, identification of the two defects can be realized by analyzing the S11 values, as the void gives rise to more reflection of microwave than the crack. During the inspection, only when the horn antenna is against the defect does the S11 show significant changes, suggesting the detection sensitivity of the method. This study lays a solid foundation for the development of microwave inspection of defects in the composite wound layer of type IV hydrogen storage vessels.
Research on the Analysis of Wear Mechanism and Improvement of the Two-way Limit Valve
Authors: Liu Zi , Chen Xu , Ren Yizhi
Published: April 2023

Aiming at the pollution fault of aircraft hydraulic system caused by the abnormal wear of the two-way limit valve, the method combining theoretical analysis and numerical simulation is used for fault location analysis based on the structural characteristics of the two-way limit valve, and the effect of the main affecting factors, such as the fitting size between parts and the position deviation of the filter holes, on the wear is studied. The results show that the wear of the two-way limit valve is mainly caused by axial assembly gap inside the product, and assembly gap greater than 0.019mm will cause abnormal wear. To solve the problem, it is suggested that no axial assembly gap will be controlled for subsequent product assembly. The two-way limit valve after 100 times of bidirectional alternating pressure supply test has normal performance and no wear phenomenon occurs.
Influence of Electrolytic Cell System on Graphite Electrode Interface Properties
Authors: Zhao Xing , Wang Peng , Chao Peipei , Liang Xinmiao , Dong Honglei
Published: April 2023

Cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS) tests are used to investigate the performance of different cell systems. For two electrode button type cell, as the lack of reference electrode and its large contact resistance, it does not have the conditions on study the electrode/electrolyte interface performance effectively. Although the three-electrode button type cell shows some improvement on potential detection of the system which can partially eliminate the adverse effects caused by electrode polarization and reduce the contact resistance, there are some limitation on the investigation of the resistance of solid electrolyte interphase (SEI) film and charge transfer process. However, it can show the variation of kinetic parameters well in the three-electrode glass type cell, which is the premise on studying the reaction mechanism, failure mechanism and electrode interface characteristics of electrode materials.
Experimental Research and Application of Lightning Protection for Radome
Authors: Li Qiuliang , Si Xiaoliang , Li Zhibao , Ding Ruihuan , Yan Wei , Sun Guoqing , Duan Zemin
Published: April 2023

In order to solve the problem of poor compatibility between lightning protection and electromagnetic wave transmittance, a new metal oxide diverter strip was selected in this paper. The breakdown characteristics of the diverter strip were studied by high voltage test, and the layout of the metal oxide diverter strip was designed and optimized by empirical formula. The lightning protection design test was carried out for a type of radome, and the feasibility of the method was verified. This method solves the problem of the radome perforation caused by the large inductive electric field of the antenna and is of great significance for the lightning protection design of the radome and its internal antenna equipment.
Development of Oxygen Concentration Control and Monitoring Device and Its Application in Mold Culture
Authors: Huang Yangyang , Cui Ming , Li Bangyu , Ma Siyu , He Lili , Liu Yangyang
Published: April 2023

An oxygen concentration control and monitoring device is developed, which can collect ambient temperature, humidity, and oxygen concentration, realize local display, local storage and network remote transmission functions, and use wireless power supply to run in the test chamber. Test chamber interface water seal. The growth verification test of aspergillus niger was carried out in the experimental device developed in this paper, and it was found that the growth of aspergillus niger on silk can be effectively inhibited under low oxygen conditions. When the oxygen concentration is lower than the threshold value of 0.7%, the growth of aspergillus niger is in a stagnant state.
Study on Mechanical Properties of Carbon Nanotube Reinforced Carbon Fiber/ Epoxy Resin Composites
Authors: Zhang Jianqin , Zhang Haiyun , Xu Jingli
Published: April 2023

Carbon nanotubes(CNTs) reinforced carbon fiber/epoxy resin composites with different amounts of carbon nanotubes were prepared by using carbon nanotubes as reinforcement. The effect of the amount of carbon nanotubes on the mechanical properties of the composites was studied. The results show that carbon nanotubes enhance the mechanical properties of carbon fiber resin composites to some extent. When the content of carbon nanotubes is 0.5%, the transverse tensile strength and modulus of the composites are increased by 32.7% and 9% respectively, and the flexural strength and modulus are increased by 12.8% and 16.4% respectively. When the content of carbon nanotubes is 0.3%, the compressive strength reaches the maximum and is increased by 28.7%.
Development of Neural Network Recognition Model for Optical Illusion Images
Authors: Wu Bo-Wen , Huang Chou-Chun , Lin Wen-Chieh
Published: April 2023

In the battlefield, tank armored vehicles have high mobility, strong defense and stable transportation capabilities, and play a role that cannot be ignored. However, its appearance and camouflage pattern design often have the camouflage effect of geometric optical illusion. The good recognition effect can ensure the safety of soldiers, and also avoid the loss of life and property of the people by accidentally hitting the surrounding houses. Therefore, how to quickly and effectively identify its appearance has become an urgent problem to be solved in the military. In this paper, the outline of the vehicle is disassembled into 12 most representative basic shapes for analysis, using image preprocessing technology, invariant moment feature extraction, and developing a BPNN(back propagation neural network) recognition model, which effectively improves the recognition rate of tank armored vehicles over above 95%.
Content and Spatial Distribution of Carbon in Shuangtaizi Estuary, China
Authors: Xia Lianqiu , Han Ruxia , Zhang Jin
Published: April 2023

Contents of total organic carbon (TOC), total inorganic carbon (TIC) and total carbon (TC) in water and sediment in Shuangtaizi estuary in China were studied. The results showed that the TIC and TC contents in water were high, and the TOC content was very low. In sediment, the TOC and TC contents were high, while the TIC was very low. TOC, TIC and TC had obvious spatial distribution characteristics in water and sediment in the area. The distribution of TOC and TC in sediment was similar, which was increase along with the distance to the mouth. The distribution of TIC and TC in water was similar. The TIC was mainly distributed at the outer mouth in surface water, while at the inner in deep water was little. The terrigenous input was the main source of carbon in the area. Carbon sequestration in the long range would convert the inorganic carbon to organic carbon.
Water Conservation Challenges and Solutions to Preserve National Food Security
Authors: Yuan Yong , Zhao Zhongnan , Tian Ying
Published: April 2023

Political security, economic security, social security, and national security have a close relationship to food security. Thus, we focus on water conservation to ensure and support national food security. Here, we also systematically summary the irrigation area and agricultural water use in our country, and analyze the challenges of food security in the view of the relationship between water resources and grain-production arrangement, agricultural water use efficiency, and farmland water conservancy investment. In light of that, we also propose some solutions and suggests, which may lay theoretic foundations for national food security.
Design of Mopping Robot
Authors: Meng Fanzhao , Li Mingwei , Yang Yonghai
Published: April 2023

With the development of Internet of Things and intelligence, cleaning mobile robots have gradually replaced the traditional manual cleaning work, and intelligence has become the main research direction of sweeping robots. As a new product in the field of service robot, mopping robot has made some achievements, but there are still many key technical problems to be solved or improved. In order to improve the safety of products in public places such as shopping malls, a robot with multiple cleaning functions such as vacuuming, mopping and drying is proposed. The mechanical mechanisms mainly include a frame, a three wheel walking mechanism, a sweeping mechanism, a mopping mechanism, a drying mechanism, etc. It can realize wifi control and mobile phone APP control, and solve the problems of the existing mopping robot such as single function, low cleaning efficiency, and the danger of slippery ground.
Design of a Bean Sprouts Device by Soilless Automatic Cultivation
Authors: Wei Yiyuan , Jiang Junxiang , Shi Yangtao , Li Zhaochang , Liang Mingyuan , Qin Likun
Published: April 2023

In order to solve problems: the existing household bean sprouts cultivation device is relatively simple; bean sprouts are easy to be contaminated in the open cultivation tank which affects the quality of bean sprouts, and the automation is poor. The bean sprouts device by soilless automatic cultivation adopts cylindrical closed culture bin structure, and the temperature and humidity sensor is set in the culture bin, which can monitor the environment in real time. At the same time, the heating plate, fan and humidifier are set in the culture bin to heat up, cool down and humidify the environment, so as to realize automatic bean sprouts cultivation. The prototype test showed that: at the temperature 26°C-30°C, humidity 85%-95%, the diameter of mung bean sprouts can reach 2.5mm, and the height can reach 150mm. the diameter of yellow bean sprouts can reach 3mm, and the height can reach 160mm. The average yield of the two sprouts was 98%. The device has the advantages of soilless, intelligence, miniaturization and simple operation, which can meet the requirements of automatic bean sprouts cultivation. It is a necessary product for household in the future.
Application and Analysis of New Pro-Environment and Water-Saving Composite Water Cooling System in Natural Gas Long Distance Pipeline
Authors: Cui Pengfei , Zhang Enlong , Wang Zhenyu , Wu Anbing , Geng Man , Chen Jianye
Published: April 2023

The traditional water cooling system of electric drive compressor in natural gas long distance pipeline uses cooling water tower, which has many problems in practical engineering: spraying water for cooling consumes a large amount of water continuously, continuous dosing and sewage discharge is needed, and winter anti-freezing measures are complex and so on. In view of the above defects of cooling water tower, this paper introduces a new type of composite water cooling system, which is completely closed, cooling without spraying water, no water consumption and discharge, daily maintenance free, its comprehensive advantages are obvious. The first composite water cooling system has been put into operation for more than 5 years, with good functions and performance, and has been widely used in electric drive compressor engineering stations.
A Method for Estimating Water Level in Sedimentation Channel with Sluice Gate
Authors: Shi Ming , Luo Xin , Luo Wenguang
Published: April 2023

In this study, based on previous studies on sedimentation, and related mathematical methods, considering from the three aspects of the water and sediment condition, the banked-up water level condition, and the sediment characteristic condition, we proposed a method for estimating water level in sedimentation channel with sluice gates, and the calculated results of it are in good agreement with the assumed results. It has high expansibility, which can be used to calculate the change of water level under other channel with sluice gates factors. In general, it can provide scientific theory and decision basis for channel with sluice gates dispatch of sedimentation channel with sluice gates in practical engineering.
Designing of Pd1/TiO2-x Nanosheets for the Electrocatalyzed Reduction of CO2
Authors: Cheng Yujin , Liu Rui
Published: April 2023

The electrochemical reduction of carbon dioxide into valuable products has attracted increasing attention to meet the demand for sustainable fuel, as well as achieving the carbon neutralization strategy. Pd is art of the state CO2RR catalyst but prone to be poisoned by the primary product CO. For the modulating the electronic state of Pd sites and therefore affinity for CO, we herein synthesized TiO2-x nanosheets to support Pd atoms. The oxygen vacancies were introduced into the titanium oxide by calcination to increase the electric conductivity of the titanium oxide, and more importantly, as a means of modifying the energy diagram of Pd. The morphology of the as-synthesized Pd1/TiO2-x was observed on high-resolution transmission electron microscope and Cs-corrected high-angle annular dark-field (HAADF)-scanning transmission electron microscope. The structure of the atomically dispersed palladium was also characterized by FTIR spectra of chemisorbed CO. The impedance of the Pd1/TiO2-x was determined to prove the improvement of its electric conductivity. The Faradaic efficiency for liquid products, mainly HCOOH/CH3OH of the electrochemical reduction of CO2 using this catalyst is 14.74%.
High Voltage Cable Fault Location Technology Based on Traveling Wave
Authors: Wang Lei , Wang Zhe , Niu Lin , Guo Lijuan , Pei Ying , Li Hongbo , Ma Zhiguang , Zhang Zhenhai , Chen Lina
Published: April 2023

High voltage cable line is an important part of power grid; its stable operation is of great significance to urban power system. This paper proposed a high voltage cable insulation monitoring system using traveling wave. The travelling wave data are collected by high precision satellite timing signal and an on-line fault location system for high voltage cable is designed.
Research and Application Practice on Technical Supervision of Nuclear Island Mechanical Equipment in NPP
Authors: Yang Lifei , Wang Qinhu , Ma Yijin , Liu Xiaolei
Published: April 2023

The safe and reliable operation of nuclear island mechanical equipment in NPP is directly related to the stable power generation of units. Strengthening the supervision and management of nuclear island mechanical equipment is an important measure to improve its reliability. This paper presents a nuclear power plant nuclear equipment purpose and significance of electric power and technical supervision, technical supervision scope, equipment identification methods, technical supervision content build process, and the reactor coolant system main pump as an example, compiled the technical supervision guide, some CPR1000 nuclear power plant in the pilot application. The existing problems in the management of the main pump group were found, and suggestions for improvement, reliability improvement and economy improvement were put forward. The practice has proved that the technical supervision of nuclear island mechanical equipment in nuclear power plants is helpful to improve the power generation capacity and economy of nuclear power plants.
Structural Design of Hub Motor Based on Bidirectional Excitation
Authors: Yao Xueshi , Zhou Meijuan , Li Lin , Zhang Xinghua , Zhong Xiaohua , Zeng Lingchao , Guo Chunyang
Published: April 2023

It is analyzed that the hub motor of new energy vehicles.Two kinds of hub motors,the inner rotor and outer rotor are designed. Their stators adopt the radial and axial bidirectional excitation.The rotor’s permanent magnets adopt Halbach distribution, and the magnetic circuit adopts composite magnetic conduction structure.The hub motor of the inner rotor is designed which includes its left stator,right stator and outer stator.The left and right stators are arranged on both sides of the axial direction of the rotor, the outer stator is arranged on the radial top side of the rotor,the three stators are fixedly sealed together,which are composed of composite iron core and coil.The rotor is composed of a yoke and permanent magnets.The permanent magnets of the rotor are pasted on the left and right side of the yoke and the outside of the top ring. The excitation magnetic flux of the three stators are distributed sinusoidally to form a three-way closed circuit.The outer rotor of the hub motor is designed,which T-shaped stator forms the radial and axial bidirectional excitation structure,which is fixedly sealed into an armature by excitation winding, composite material iron core and resin.The composite material iron core is composed of steel fiber reinforced epoxy resin.The rotor is arranged on the outside of the T-shaped stator to form an outer rotor.The T-shaped stator is fixed on the shaft, and the rotor is installed on the shaft by use of bearings. The above two hub motors have high output torque/power density, low heating effect, light weight and simple assembly.They are suitable for electric car series.
Probe into the Influence of Water Content upon the Safety and Stability of Loess Slope Based on the Garden Project of Hejin Cherry Valley
Authors: Liu Xiaoxuan
Published: April 2023

In order to consider the influence of soil moisture content change on the slope stability of Hejin Cherry Valley Garden Project, this paper firstly selects soil samples at typical locations to obtain the shear strength test results of loess under different moisture content; Then, based on rhinoceros and FLAC3D software, the strength reduction method is used to analyze the slope stability, and the impact of water content on the slope stability is comprehensively evaluated according to the safety factor, plastic zone and shear strain. The results show that when the soil is completely dry, the cohesion and internal friction angle are both maximum; When the water content is 11%, the internal friction angle and cohesion are at a low level; Under different water content conditions, there is a watershed for slope stability. The water content is higher than 11%, and the safety factor is lower than 1.3. With the rise of water content, the maximum shear strain of the slope spreads from the toe to the slope surface. It is found in the comprehensive plastic zone the slope surface near the top of the slope is prone to landslide. The research results of this paper can provide reference and guidance for the stability and safety of loess slope after the construction of landscape architecture in Central Plains.
Miniaturization of Biogas Upgrading Via High Pressure Water Scrubbing to Enhance Economic Competitiveness of Distributed Biomethane
Authors: Qian Wei , Kang Zezhong , Luo Laixing , Zheng Zongming , Xiao Xianbin , Qin Wu
Published: April 2023

Biogas is an important clean and low carbon energy for rural area, which is confronted with the low heat value, pollutant emission during combustion. The pollutant absorbing technology was employed to develop the small scale portable biogas upgrading equipment to remove CO2, H2S and other impurities in this work. The scheme based on the high pressure water scrubbing technology (HPWS) were proposed including adsorption, flashing, stripping and water recovery. Aspen Plus were used to investigate the effect of adsorption pressure, number of plates, and flash pressure on CH4 purification. The mole fraction of CH4 in final stream increased to 95.6% and levelled off around 97% with the increasing of flash pressure and absorber pressure. The water consumption will decrease with the increase of the number of plates. When the number of plates is above 7, the reduction of water consumption will not be obvious. The principle equipment was developed and tested, indicating the high separation efficiency.
Finite Element Simulation and Experiment of Temporary Active Transverse Brace of Inward-inclined Bridge Tower Construction
Authors: Chen H , Niu YW , Bai GY , Sai ZY
Published: April 2023

For the bridge tower with large inclination angle, the beam element in Midas finite element software is used to model and analyze the bridge tower structure, and its accuracy is difficult to guarantee. In this paper, taking the construction of a suspension bridge’s inward-inclined tower as the research background, the finite element simulation of the inward-inclined bridge tower is carried out by using the two modeling methods of the beam element and the solid element. The calculation accuracy of the beam element model, the specific position and the jacking force applied by the active transverse brace of the inward-inclined bridge tower are determined, and the field test of the tower bottom stress during the construction process is performed. The results show that: when the inclination angle of the bridge tower is small (5 °), the beam element element is used for modeling and analysis, which has fast calculation speed and high calculation accuracy; When the inclination angle is 15 °, the error of the beam element model exceeds 30%, and it is recommended to use the solid model for calculation; the active cross brace plays a key role in controlling the stress at the bottom of the tower column before the lower cross beam is applied. And after the construction of the cross beam, the active cross brace forms a closed frame structure with the lower tower column, and the subsequent cross brace has little impact on the stress at the bottom of the tower column; Compared with increasing the number of temporary cross braces, increasing the jacking force can improve the stress at the bottom of the tower. And by adjusting the position of the active cross brace and applying the appropriate active jacking force, the stress at the root of the tower column can be greatly improved.
Design and Static Analysis of Long-span Steel Truss Suspension Bridge
Authors: Geng WB , Yi Q , Yang YH , Li C , Kang YB , Cui PP
Published: April 2023

In order to effectively improve the structural safety status of suspension bridges, this paper proposes a design and static analysis method of long span steel truss suspension bridge based on Midas civil finite element calculation software. Taking the Guojiatuo Yangtze River Bridge as a case, the paper studies the mechanical characteristics of the key parts of the bridge in the completion state and operation stage, and determines the structural safety state. The results show that the minimum safety factor of main cable is 2.64, and the minimum safety factor of the suspender is 3.90, and the maximum downward deflection of the main beam is 1.231m < L/400. The structural strength and stiffness can meet the design requirements.
Numerical Study on the Evolution Law of Explosion Response of Extra-wide Self-anchored Suspension Bridge under the Influence of Concrete Shrinkage and Creep
Authors: Zhou GP , Lin ZC , wang MY , Fan J , zhang YY
Published: April 2023

In order to deeply reveal the evolution law of explosion response of super wide self anchored suspension bridge under the influence of concrete shrinkage and creep, the evolution law of explosion response of extra-wide self-anchored suspension bridge under the influence of concrete shrinkage and creep is studied by simulation experiment. Based on a real bridge, the dynamic response of vertical displacement of the bottom plate of the bridge under explosion load at different ages is analyzed by numerical simulation. Firstly, the refined finite element model of the whole bridge is established by using SolidWorks software and Hypermesh software; Secondly, the explosion load is applied by ANSYS/LS-DYNA software and *LOAD_BLAST_ENHANCED (LBE) method, and the reliability of the calculation method is verified by combining the explosion test results of concrete members in the literature; Finally, the dynamic response of the bridge at different ages is analyzed by modifying the elastic modulus of the material to make the main girder reach the linearity predicted in the literature. The results show that under the action of explosion shock wave, the stress of the concrete element on the top plate of the main girder reaches the limit value and fails, forming an elliptical breach. With the increase of the age of the bridge, the vertical displacement of the bottom plate in the middle of the bridge span increases continuously, and the growth rate is “fast in front and slow in back”, which is consistent with the impact of concrete shrinkage and creep on the bridge. The results of this paper can provide an important basis for the anti-explosion protection and reinforcement of concrete extra-wide self-anchored suspension bridge.
Research on Seismic Reduction and Isolation Design of Prefabricated Viaduct in Areas of High Seismic Risk
Authors: Zhan YY , Deng XW , Dang XZ , Luo XH , Zhang CN
Published: April 2023

Seismic isolation design is an effective and economical method to protect precast viaducts from severe earthquake damage. Correct selection of bearings is one of the common methods to achieve this goal. In order to optimize the vibration isolation performance of prefabricated viaducts, this paper compares the vibration isolation performance of lead rubber bearings (LRB) and laminated bearings (LB). The lead rubber bearing (LRB) and laminated bearing are respectively applied to the same analysis model of prefabricated viaduct. The seismic responses of bearings and structural members are analyzed by dynamic analysis method, and the typical seismic responses, including internal force, displacement, hysteresis curve and residual deformation, are compared. The results show that LRB has higher isolation efficiency and better self centering ability.
Research on Optimization Design of the Mix Proportion of Xiamen Second East Passage Tunnel
Authors: Liu JH , Zhu YM , Chen XH , Liu S
Published: April 2023

Because of the poor hydration heat and shrinkage of the tunnel constructed in sections, structural cracks are easy to occur, and the concrete mix ratio is very important. In order to achieve accurate concrete mix proportion, the paper has optimized the concrete mix proportion of Xiamen East Second Passage. The early mechanical properties and impermeability of the concrete before and after the optimization of the mix ratio were tested. The results show that the cement content in the original design mix proportion is high, the early strength of concrete is excessive, and high hydration heat and shrinkage are easy to occur during construction. The early mechanical properties and impermeability of the optimized mix proportion concrete can meet the design and construction requirements. The conclusions can provide guidance for the construction of similar projects.he construction of similar projects.
Rapid Intelligent Risk Assessment of Bridges under Typhoon Disasters
Authors: Yuan JC , Liu XL , Ding Y , Wang XJ , Cao ZB , Zhou JH
Published: April 2023

In order to improve the risk early-warning performance of highway bridges caused by typhoon disasters, a fast and intelligent risk assessment model for highway bridges is proposed in this paper. A three-level accident possibility index system is established in which the top-level index is the possibility of bridge accident, the second-level indices comprise the accident causing factor, the surrounding environment factor, and the accident bearing body, and the third-level indices are selected from the disaster conditions and the bridge’s own technical conditions. With the rapid risk assessment model of highway bridges under typhoon disasters, the intelligent risk assessment software platform is developed. In the case analysis, the automatic and intelligent risk assessment of highway bridges in Ningbo under Typhoon “Lekima” on August 10, 2019, was realized.
Temperature Effects on Steel Truss Structure under Different Bearing Stiffness Conditions
Authors: Fan DL , Xiao F , Fan J
Published: April 2023

The temperature response of steel truss structure is affected by the boundary conditions. If the stress caused by temperature cannot be completely released, the structure may be damaged. In order to deeply reveal the laws of temperature and steel truss structure under different boundary conditions, this paper studied the influence of temperature on steel truss structure under different boundary conditions through experiments. First, the temperature effects on a sample member under different bearing stiffnesses were investigated using the stiffness method. Second, a truss structure finite element model was built to study the temperature response. The results indicated that the maximum axial stress of the member significantly decreased when the boundary condition of the structure was transferred from the fixed to a roller bearing.
Analysis of Damage Mechanism of Heihe Bridge during the Maduo Earthquake
Authors: Huang Y , Yin MC , He J , Cai LW
Published: April 2023

It is of great significance to discuss the earthquake damage mechanism of the bridge. In this paper, the seismic damage mechanism of Heihe Bridge is analyzed based on the post earthquake data. Firstly, the seismic response of Heihe Bridge is analyzed based on the finite element software Midas/Civil, and the model of Heihe Bridge (upward) is established using the data of Dawu strong earthquake records near the bridge site; Then, the influence of bridge connecting plates on the seismic response of small and medium span simply supported girder bridges is studied, and the models with and without connecting plates are established. Finally, through the experimental analysis of the ground motion response, the internal force relationship between the connecting plate and the substructure of the bridge is discussed. The results show that:1)Abutment plays an important role in restraining the displacement of main beam along the bridge. Bridge connecting plate is an important seismic measure. (2) Using the three-dimensional ground motion simulation method of random finite faults, the seismic response analysis of the given USGS ground motion can better simulate the failure mechanism of the bridge. (3)The seismic response of the structural system is determined by the different layout of the bridge deck.
Experimental Study on Load of Continuous Steel Truss Bridge Stiffened by Rigid Suspension Cable for Highway and Rail
Authors: Bai GL , Ke P , Liu X , Ran YC
Published: April 2023

In order to reveal the stress law of rigid suspension stiffened continuous steel truss bridge under highway and crowd loads, a highway rail bridge is taken as the supporting project, and the load test method is used to verify it. Firstly, the completed bridge state (the dead load of the lower track) is simulated by laying water bags on the lower deck, which solves the problem of asynchronous construction of highway and track. Then, the stress, deformation results and change rules of this kind of bridge under the test load are summarized by simulating the load action of highway and crowd through the loading vehicle, which can provide a reference for the load test of similar bridges.
Technical Architecture and Evolution Analysis of Measurement Data Sharing for Power IoTs
Authors: Liang J , Zhu S , Lin H
Published: April 2023

With the development of the Internet of Things (IoT), a large number of devices are connected to IoT. Traditional data sharing architecture is increasingly unable to meet business needs. In order to solve this problem, the paper integrates the measurement data of multiple systems, and proposes a new data sharing architecture with the Internet of Things Management Platform (ITMP) and the real-time measurement center as the core. The architecture realizes unified access and management of equipment through ITMP, avoiding problems such as data analysis difficulty, complex data collection process and big data delay when multiple systems access data. Then, the measurement center realizes fast real-time data processing and distributes the data to different applications to improve data utilization and productivity. The application results of this architecture in the actual environment show that the active maintenance and active maintenance of the distribution network under the new architecture reduce the time for fault diagnosis of the distribution network from 10 minutes to 1 minute, and support the transition from passive to active.
Ground Fault Identification in Distribution Network Based on MMC Injection Detection Signal Strategy
Authors: Liu WH , Liu YC , Wang JJ , Wang YX , Lun D
Published: April 2023

In order to improve the identification efficiency and accuracy of distribution network ground fault identification methods, this paper proposes a distribution network ground fault identification method based on MMC injection detection signal strategy. Extract the fault information of distribution network grounding line, calculate the current component of three-phase current, and obtain the grounding fault data of distribution network.The detection current of distribution network is obtained by injection signal detection strategy. The fault information matrix is formed by using the detection current information, and the time-frequency characteristics of MMC injection detection signal strategy are obtained according to the actual situation.The wavelet transform is used to remove the clutter in the fault feature vector, and the normalized processing is used to obtain and process the ground fault vector.According to the wavelet function, the characteristics of the distribution network ground fault signal are determined. Cassie model and Mayr model are used to obtain the final distribution network ground fault identification model to realize the distribution network ground fault identification.The experimental results show that the accuracy of the method can reach 96.1%, and the time of fault identification is only 25s. The above results show that the method can effectively improve the effectiveness of distribution network ground fault identification.