The purpose of this study is to analyze the application of ultrasonic non-destructive testing technology in bridge engineering.During the research phase,based on literature collection and reading,as well as the analys...The purpose of this study is to analyze the application of ultrasonic non-destructive testing technology in bridge engineering.During the research phase,based on literature collection and reading,as well as the analysis of bridge inspection materials,the principle of ultrasonic non-destructive testing technology and its adaptability to bridge engineering are elaborated.Subsequently,starting from the preparation work before inspection until damage assessment,the entire process of ultrasonic non-destructive testing is studied,and finally,a technical system of ultrasonic non-destructive testing for bridge engineering that runs through the entire process is formed.It is hoped that this article can provide technical reference value for relevant units in China,and promote the high-quality development of China’s bridge engineering from a macro perspective.展开更多
In the current social environment,the importance of energy conservation and emission reduction is increasing day by day for both the country and its people.Electronic and electrical products,as important items for peo...In the current social environment,the importance of energy conservation and emission reduction is increasing day by day for both the country and its people.Electronic and electrical products,as important items for people’s production and life,require high attention from industry insiders in terms of their energy efficiency testing.Relying on energy efficiency testing can achieve the goal of energy conservation and emission reduction,and related quality control technologies will also inject new momentum into the green development of the industry.This article will discuss the practical strategies of quality control technology for energy efficiency testing of electronic and electrical products based on the significance of such testing,hoping to provide some help.展开更多
Current sway test platforms for marine nuclear equipment face challenges in meeting the GJB 150.23A requirements.This is primarily because of the performance limitations of conventional actuators under extreme marine ...Current sway test platforms for marine nuclear equipment face challenges in meeting the GJB 150.23A requirements.This is primarily because of the performance limitations of conventional actuators under extreme marine conditions.This study aimed to overcome these constraints using an innovative parallel mechanism design.We developed a novel 6-PUS parallel platform featuring six kinematic chains with hybrid series-parallel actuators.Each chain combines(1)force-speed adaptive transmission,(2)redundant motor-driven dual-screw actuation,and(3)passive load-balancing mechanisms.Comprehensive kinematic/dynamic modeling and experimental validation were conducted.Tests demonstrated the capability of the platform to achieve cyclic speeds of±45°/7 s and±30°/3 s while supporting 10-ton loads.Successful sway tests on nuclear components(reactor pressurizer and control rod drive mechanism)confirmed the operational reliability.This work presented three key innovations:(1)a new parallel-platform architecture that overcomes the limitations of conventional actuators;(2)integrated hybrid actuation with adaptive transmission;and(3)high-speed,heavy-load performance that meets stringent marine testing standards.This solution significantly advances nuclear equipment qualification testing technology.展开更多
Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving...Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously.Here,by regulating the surface charge characteristics of halloysite nanotube(HNT),we propose a concept of lithium-ion dynamic interface(Li^(+)-DI)engineering in nano-charged CPE(NCCPE).Results show that the surface charge characteristics of HNTs fundamentally change the Li^(+)-DI,and thereof the mechanical and ion-conduction behaviors of the NCCPEs.Particularly,the HNTs with positively charged surface(HNTs+)lead to a higher Li^(+)transference number(0.86)than that of HNTs-(0.73),but a lower toughness(102.13 MJ m^(-3)for HNTs+and 159.69 MJ m^(-3)for HNTs-).Meanwhile,a strong interface compatibilization effect by Li^(+)is observed for especially the HNTs+-involved Li^(+)-DI,which improves the toughness by 2000%compared with the control.Moreover,HNTs+are more effective to weaken the Li^(+)-solvation strength and facilitate the formation of Li F-rich solid-electrolyte interphase of Li metal compared to HNTs-.The resultant Li|NCCPE|LiFePO4cell delivers a capacity of 144.9 m Ah g^(-1)after 400 cycles at 0.5 C and a capacity retention of 78.6%.This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.展开更多
A new equivalent center of mass model of FPBs (friction pendulum bearings) is introduced, and based on this model, coefficient j of the equivalent center of mass separating from the sliding surface is defined. It is t...A new equivalent center of mass model of FPBs (friction pendulum bearings) is introduced, and based on this model, coefficient j of the equivalent center of mass separating from the sliding surface is defined. It is thought in theory that j has a significant impact on the isolation parameter of FPBs, since the equivalent post-yielding stiffness and friction coefficients are not simply determined by sliding radius and sliding friction pairs. The results of numerical simulation analysis using ABAQUS conducted on two groups of FPBs support this viewpoint. For FPBs with the same sliding radius and sliding friction pairs, the FPB modules of structural analysis software such as ETABS could only distinguish the equivalent transformation using j one by one. The seismic response data obtained in a base isolation calculation example of FPBs are very different, which reveals that j’s impact on the isolation effectiveness of FPBs cannot be ignored. The introduction of j will help improve the classical structural theory of FPBs and the weak points of structural analysis software based on this theory, which is important in achieving more accurate analyses in structural design.展开更多
This study addresses the changes in acceleration,pore water pressure and Fourier spectrums of different types of seismic waves with various amplitudes via large-scale shaking table tests from two sites:a sand-containi...This study addresses the changes in acceleration,pore water pressure and Fourier spectrums of different types of seismic waves with various amplitudes via large-scale shaking table tests from two sites:a sand-containing regional site and an all-clay site.Comparative analyses of the test results show that the pore water pressures in sand-soil layers of the regional site initially increase and then decrease as the amplitudes of the seismic accelerations increase.The actions of the vertical and vibrational seismic waves contribute to greater pore water pressures.The amplification coefficient of the sand-layer regional site becomes smaller as the seismic waves grow stronger,so that both sites are capable of filtering high frequencies and amplifying low frequencies of seismic waves.This is more apparent with the increase in the peak value of the acceleration,and the natural vibration frequencies of both sites decrease with the transmission of the seismic waves from the basement to the ground surface.The decreasing frequency value of the sand-containing regional site is smaller than that of the all-clay site.展开更多
Face-centered cubic (f.c.c.) high entropy alloys (HEAs) are attracting more and more attention owing to their excellent strength and ductility synergy, irradiation resistance, etc. However, the yield strength of f.c.c...Face-centered cubic (f.c.c.) high entropy alloys (HEAs) are attracting more and more attention owing to their excellent strength and ductility synergy, irradiation resistance, etc. However, the yield strength of f.c.c. HEAs is generally low, significantly limiting their practical applications. Recently, the alloying of W has been evidenced to be able to remarkably improve the mechanical properties of f.c.c. HEAs and is becoming a hot topic in the community of HEAs. To date, when W is introduced, multiple strengthening mechanisms, including solid-solution strengthening, precipitation strengthening (μphase,σphase, and b.c.c. phase), and grain-refinement strengthening, have been discovered to be activated or enhanced. Apart from mechanical properties, the addition of W improves corrosion resistance as W helps to form a dense WO_(3) film on the alloy surface. Until now, despite the extensive studies in the literature, there is no available review paper focusing on the W doping of the f.c.c. HEAs. In that context, the effects of W doping on f.c.c. HEAs were reviewed in this work from three aspects, i.e., microstructure,mechanical property, and corrosion resistance. We expect this work can advance the application of the W alloying strategy in the f.c.c. HEAs.展开更多
With increasing industrial activities,mercury has been largely discharged into environment and caused serious environmental problems.The growing level of mercury pollution has become a huge threat to human health due ...With increasing industrial activities,mercury has been largely discharged into environment and caused serious environmental problems.The growing level of mercury pollution has become a huge threat to human health due to its significant biotoxicity.Therefore,the simple and fast means for on-site monitoring discharged mercury pollution are highly necessary to protect human beings from its pernicious effects in time.Herein,a"turn off"fluorescent biosensor(mCherry L199 C)for sensing Hg2+was successfully designed based on direct modification of the chromophore environment of fluorescent protein mCherry.For rapid screening and characterization,the designed variant of mCherry(mCherry L199 C)was directly expressed on outer-membrane of Escherichia coli cells by cell surface display technique.The fluorescent biosensor was characterized to have favorable response to Hg2+at micromole level among other metal ions and over a broad pH range.Further,the cells of the fluorescent biosensor were encapsulated in alginate hydrogel to develop the cells-alginate hydrogel-based paper.The cells-alginate hydrogel-based paper could detect mercury pollution in 5 min with simple operation process and inexpensive equipment,and it could keep fluorescence and activity stable at 4℃ for 24 hr,which would be a high-throughput screening tool in preliminarily reporting the presence of mercury pollution in natural setting.展开更多
The electromagnetic environment of laneways in underground coal mines is an important area for the design of new electronic products,as well as a fundamental space for mine monitoring,surveillance,communications and c...The electromagnetic environment of laneways in underground coal mines is an important area for the design of new electronic products,as well as a fundamental space for mine monitoring,surveillance,communications and control systems.An investigation of electromagnetic interference in coal mines is essential for the enhancement of performances of these systems.In this study,a new field method is provided in which radiated emission tests in coal mine laneways have been carried out.We conclude that:1) the wiring motor vehicles can radiate interference with a bandwidth up to 1 GHz and with an amplitude 10 dBμV/m higher than the background noise;2) the PHS(Personal Handy phone System) mobile communication system can cause interference 40 dBμV/m higher than the background noise;3) an interference 25 dBμV/m higher than the background noise can be generated during the communication at a working bandwidth of 48.8 MHz;and 4) power cables,battery vehicles as well as mechanical and electrical dong rooms have little effect on the electromagnetic radiation environment in coal mine tunnels.展开更多
This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview ...This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview of a certain bridge construction project studied and acoustic non-destructive testing technology and the application of acoustic non-destructive testing technology in actual testing.This analysis hopes to provide some guidelines for acoustic non-destructive testing of modern concrete bridge projects.展开更多
To measure projectile attitude in space flight, based on continuous wave （CW） radar, a new micro-Doppler effect testing technique is developed in this paper. It also establishes radar testing model for attitude of f...To measure projectile attitude in space flight, based on continuous wave （CW） radar, a new micro-Doppler effect testing technique is developed in this paper. It also establishes radar testing model for attitude of flying projectile and resolve micro-Doppler effect of projectile motion attitude. By distinguishing and geting attitude parameters such as micro-motion period, this technique can in- tuitively estimate the flight stability of projectile, and the validity of this technique is proved accord- ing to flight tests.展开更多
Assessment of railway wheel slide protection(WSP) systems involves the execution of complex experimental activities that are quite expensive and time-consuming, since they involve the physical reproduction of degraded...Assessment of railway wheel slide protection(WSP) systems involves the execution of complex experimental activities that are quite expensive and time-consuming, since they involve the physical reproduction of degraded adhesion conditions on a real railway line. WSP is devoted to regulating applied braking forces to avoid excessive wheel sliding in case of degraded adhesion conditions between wheel and rail. WSP must be also compliant to safety specifications related to assured braking performances and consumed air. Hardware in the loop(HIL) testing offers an affordable and sustainable way to accelerate these activities optimizing cost, duration and safety of experimental activities performed online. HIL test rigs are subjected to continuous updates, customization and natural ageing of their components. This work investigates the criteria that can be adopted to assure a continuous monitoring and validation of a real WSP test rig, the Italian test rig of Firenze Osmannoro.展开更多
This paper describes the use of steady-state solar simulator for CIGS thin-film photovoltaic module hot-spot endurance test. In the study, not only are test procedures of hot-spot endurance test in IEC 61646 discussed...This paper describes the use of steady-state solar simulator for CIGS thin-film photovoltaic module hot-spot endurance test. In the study, not only are test procedures of hot-spot endurance test in IEC 61646 discussed, but also how to evaluate the performance of steady-state solar simulator by IEC 60904-9 is presented. Three CIGS thin-film PV modules with the same types are used for hot-spot endurance test in case study. It is found that some of the cell damages and visual defects on tested PV modules are clearly observed.展开更多
Segregation of solute atoms in the center of thick plates of the tempered steel can cause an inhomogeneous structural transformation and generate micron-sized inclusions,which leads to lamellar tearing of thick plate ...Segregation of solute atoms in the center of thick plates of the tempered steel can cause an inhomogeneous structural transformation and generate micron-sized inclusions,which leads to lamellar tearing of thick plate and decreases the plasticity and toughness.The formation and fragmentation mechanisms of micron-sized inclusions,like MnS and(Nb,Ti)C,in the center of thick plates were investigated by using thermodynamic calculations,finite element simulations,and electron backscatter diffraction characterization techniques.The results show that micron-sized inclusions nucleate and grow in the liquid phase,and under tensile loading,they exhibit three fragmentation mechanisms.The local stress during the fragmentation of inclusions is lower than the critical fracture stress of adjacent grains,and phase boundaries can effectively impede crack propagation into the matrix.The existence of a low proportion of high-angle grain boundaries(58.1%)and high Kernel average misorientation value(0.534°)in the segregation band promotes inclusions fragmentation and crack propagation.The difference in crack initiation and propagation direction caused by the morphology of inclusions and physical properties,as well as different matrix arrest abilities,is the main reasons for the diversity of inclusion fragmentation.展开更多
In the process of food testing,human operation is an important variable affecting the experimental results.In order to reasonably avoid the influence of human subjective operation behavior on the accuracy of detection...In the process of food testing,human operation is an important variable affecting the experimental results.In order to reasonably avoid the influence of human subjective operation behavior on the accuracy of detection results,the laboratory information management system was used as the information platform to design a high-throughput laboratory automation pre-treatment system based on the deep integration of mechanical principles,visual analysis,high-speed conduction,intelligent storage and other technical systems.The experimental results showed that the system could shorten the sample circulation cycle,effectively improve the laboratory biosafety,and meet the requirements of high-throughput processing of samples.展开更多
Based on the analysis of food testing standards (according to parameters, categories and methods), this paper puts forward an integrated reference method for food testing standards. At the same time, the innovation of...Based on the analysis of food testing standards (according to parameters, categories and methods), this paper puts forward an integrated reference method for food testing standards. At the same time, the innovation of food testing methods puts forward some "normal" requirements from aspects of coverage, recovery rate and consistency with determination standards.展开更多
This article presents a real-life project that aimed to evaluate the safety of traffic vehicles on old bridges without any prior data.The project involved various safety inspections,including conventional,static,and d...This article presents a real-life project that aimed to evaluate the safety of traffic vehicles on old bridges without any prior data.The project involved various safety inspections,including conventional,static,and dynamic load inspections and safety assessments.After conducting these tests,it was concluded that the structure of the old bridge is relatively safe,with only a few bumps.The bridge could function normally following appropriate treatment.The analysis provides valuable insights into the assessment of the quality and safety of such bridges to ensure the safe driving of heavy vehicles.展开更多
This article uses real engineering projects as examples to analyze how static load test technology is applied in testing the bridge-bearing capacity.The analysis covers aspects such as testing section layout,test load...This article uses real engineering projects as examples to analyze how static load test technology is applied in testing the bridge-bearing capacity.The analysis covers aspects such as testing section layout,test load and efficiency coefficient,loading plan,evaluation optimization,test result modification,and result evaluation.The aim is to support the accurate detection and evaluation of bridge-bearing capacity.展开更多
In order to ensure the healthy growth of agricultural products and provide food for more people, the use of pesticides is essential. If the pesticide residue on food is too much, it will cause certain potential food s...In order to ensure the healthy growth of agricultural products and provide food for more people, the use of pesticides is essential. If the pesticide residue on food is too much, it will cause certain potential food safety hazard. After eating the food contaminated by the residual agricultural products, the light condition is manifested as dizziness and vomiting, which may lead to poisoning and death. In order to strengthen the detection and identification of pesticide residues in agricultural products, it is necessary to strengthen the supervision and supervision of food safety testing. This article mainly analyzes and discusses the detection technology of pesticide residues in agricultural products and food safety detection for reference.展开更多
With the development of the times, people's technology in all walks of life has also improved with the development of the times. Food ranks first in people's needs. Therefore, it is very important whether the ...With the development of the times, people's technology in all walks of life has also improved with the development of the times. Food ranks first in people's needs. Therefore, it is very important whether the food imported meets the regulations and health standards. In order to ensure the production and the health of the crops, people will use pesticides according to the situation during the growth of agricultural products. This will result in pesticide residues that may exist on things. If there are more pesticide residues, there will be potential safety hazards. Generally, symptoms such as dizziness and vomiting will occur after ingesting the pesticide residues. In serious cases, people may be poisoned and killed. Therefore, to strengthen the detection of pesticides in agricultural products has become the focus of attention, and the main direction is to strengthen the supervision and supervision of food safety testing. This article is mainly based on the detection of pesticide residues in agricultural products and food safety testing techniques for analysis and exploration, hoping to provide more advice to the relevant units.展开更多
文摘The purpose of this study is to analyze the application of ultrasonic non-destructive testing technology in bridge engineering.During the research phase,based on literature collection and reading,as well as the analysis of bridge inspection materials,the principle of ultrasonic non-destructive testing technology and its adaptability to bridge engineering are elaborated.Subsequently,starting from the preparation work before inspection until damage assessment,the entire process of ultrasonic non-destructive testing is studied,and finally,a technical system of ultrasonic non-destructive testing for bridge engineering that runs through the entire process is formed.It is hoped that this article can provide technical reference value for relevant units in China,and promote the high-quality development of China’s bridge engineering from a macro perspective.
文摘In the current social environment,the importance of energy conservation and emission reduction is increasing day by day for both the country and its people.Electronic and electrical products,as important items for people’s production and life,require high attention from industry insiders in terms of their energy efficiency testing.Relying on energy efficiency testing can achieve the goal of energy conservation and emission reduction,and related quality control technologies will also inject new momentum into the green development of the industry.This article will discuss the practical strategies of quality control technology for energy efficiency testing of electronic and electrical products based on the significance of such testing,hoping to provide some help.
基金Supported by Shanghai Nuclear Engineering Research&Design Institute Co.,Ltd.
文摘Current sway test platforms for marine nuclear equipment face challenges in meeting the GJB 150.23A requirements.This is primarily because of the performance limitations of conventional actuators under extreme marine conditions.This study aimed to overcome these constraints using an innovative parallel mechanism design.We developed a novel 6-PUS parallel platform featuring six kinematic chains with hybrid series-parallel actuators.Each chain combines(1)force-speed adaptive transmission,(2)redundant motor-driven dual-screw actuation,and(3)passive load-balancing mechanisms.Comprehensive kinematic/dynamic modeling and experimental validation were conducted.Tests demonstrated the capability of the platform to achieve cyclic speeds of±45°/7 s and±30°/3 s while supporting 10-ton loads.Successful sway tests on nuclear components(reactor pressurizer and control rod drive mechanism)confirmed the operational reliability.This work presented three key innovations:(1)a new parallel-platform architecture that overcomes the limitations of conventional actuators;(2)integrated hybrid actuation with adaptive transmission;and(3)high-speed,heavy-load performance that meets stringent marine testing standards.This solution significantly advances nuclear equipment qualification testing technology.
基金the financial support from the National Natural Science Foundation of China(52203123 and 52473248)State Key Laboratory of Polymer Materials Engineering(sklpme2024-2-04)+1 种基金the Fundamental Research Funds for the Central Universitiessponsored by the Double First-Class Construction Funds of Sichuan University。
文摘Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously.Here,by regulating the surface charge characteristics of halloysite nanotube(HNT),we propose a concept of lithium-ion dynamic interface(Li^(+)-DI)engineering in nano-charged CPE(NCCPE).Results show that the surface charge characteristics of HNTs fundamentally change the Li^(+)-DI,and thereof the mechanical and ion-conduction behaviors of the NCCPEs.Particularly,the HNTs with positively charged surface(HNTs+)lead to a higher Li^(+)transference number(0.86)than that of HNTs-(0.73),but a lower toughness(102.13 MJ m^(-3)for HNTs+and 159.69 MJ m^(-3)for HNTs-).Meanwhile,a strong interface compatibilization effect by Li^(+)is observed for especially the HNTs+-involved Li^(+)-DI,which improves the toughness by 2000%compared with the control.Moreover,HNTs+are more effective to weaken the Li^(+)-solvation strength and facilitate the formation of Li F-rich solid-electrolyte interphase of Li metal compared to HNTs-.The resultant Li|NCCPE|LiFePO4cell delivers a capacity of 144.9 m Ah g^(-1)after 400 cycles at 0.5 C and a capacity retention of 78.6%.This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.
基金973 Program under Grant No.2012CB723304Program for Changjiang Scholars and Innovative Research Team in UniversityNational Science Foundation Program under Grant No.91315301-07
文摘A new equivalent center of mass model of FPBs (friction pendulum bearings) is introduced, and based on this model, coefficient j of the equivalent center of mass separating from the sliding surface is defined. It is thought in theory that j has a significant impact on the isolation parameter of FPBs, since the equivalent post-yielding stiffness and friction coefficients are not simply determined by sliding radius and sliding friction pairs. The results of numerical simulation analysis using ABAQUS conducted on two groups of FPBs support this viewpoint. For FPBs with the same sliding radius and sliding friction pairs, the FPB modules of structural analysis software such as ETABS could only distinguish the equivalent transformation using j one by one. The seismic response data obtained in a base isolation calculation example of FPBs are very different, which reveals that j’s impact on the isolation effectiveness of FPBs cannot be ignored. The introduction of j will help improve the classical structural theory of FPBs and the weak points of structural analysis software based on this theory, which is important in achieving more accurate analyses in structural design.
基金National Program on Key Basic Research Project(973 Program)under Grant No.2011CB013606Program for Changjiang Scholars and Innovative Research Team in University under Grant No.IRT13057+1 种基金Key Program of National Natural Science Foundation of China under Grant No.51438004the Research Fund for the Doctoral Program of Higher Education of China under Grant No.20124410110004
文摘This study addresses the changes in acceleration,pore water pressure and Fourier spectrums of different types of seismic waves with various amplitudes via large-scale shaking table tests from two sites:a sand-containing regional site and an all-clay site.Comparative analyses of the test results show that the pore water pressures in sand-soil layers of the regional site initially increase and then decrease as the amplitudes of the seismic accelerations increase.The actions of the vertical and vibrational seismic waves contribute to greater pore water pressures.The amplification coefficient of the sand-layer regional site becomes smaller as the seismic waves grow stronger,so that both sites are capable of filtering high frequencies and amplifying low frequencies of seismic waves.This is more apparent with the increase in the peak value of the acceleration,and the natural vibration frequencies of both sites decrease with the transmission of the seismic waves from the basement to the ground surface.The decreasing frequency value of the sand-containing regional site is smaller than that of the all-clay site.
基金financially supported by the National Key R&D Program of China (No.2021YFA1200203)the National Natural Science Foundation of China (Nos.51922026 and 51975111)+1 种基金the Fundamental Research Funds for the Central Universities (No.N2202015,N2002005,and N2105001)the 111 Project of China (No.BP0719037 and B20029)。
文摘Face-centered cubic (f.c.c.) high entropy alloys (HEAs) are attracting more and more attention owing to their excellent strength and ductility synergy, irradiation resistance, etc. However, the yield strength of f.c.c. HEAs is generally low, significantly limiting their practical applications. Recently, the alloying of W has been evidenced to be able to remarkably improve the mechanical properties of f.c.c. HEAs and is becoming a hot topic in the community of HEAs. To date, when W is introduced, multiple strengthening mechanisms, including solid-solution strengthening, precipitation strengthening (μphase,σphase, and b.c.c. phase), and grain-refinement strengthening, have been discovered to be activated or enhanced. Apart from mechanical properties, the addition of W improves corrosion resistance as W helps to form a dense WO_(3) film on the alloy surface. Until now, despite the extensive studies in the literature, there is no available review paper focusing on the W doping of the f.c.c. HEAs. In that context, the effects of W doping on f.c.c. HEAs were reviewed in this work from three aspects, i.e., microstructure,mechanical property, and corrosion resistance. We expect this work can advance the application of the W alloying strategy in the f.c.c. HEAs.
基金supported by the Natural Science Foundation of Guangxi Province(No.2018JJB120049)National Natural Science Foundation of China(No.31800631)+1 种基金the BAGUI Scholar Program of Guangxi Province of China。
文摘With increasing industrial activities,mercury has been largely discharged into environment and caused serious environmental problems.The growing level of mercury pollution has become a huge threat to human health due to its significant biotoxicity.Therefore,the simple and fast means for on-site monitoring discharged mercury pollution are highly necessary to protect human beings from its pernicious effects in time.Herein,a"turn off"fluorescent biosensor(mCherry L199 C)for sensing Hg2+was successfully designed based on direct modification of the chromophore environment of fluorescent protein mCherry.For rapid screening and characterization,the designed variant of mCherry(mCherry L199 C)was directly expressed on outer-membrane of Escherichia coli cells by cell surface display technique.The fluorescent biosensor was characterized to have favorable response to Hg2+at micromole level among other metal ions and over a broad pH range.Further,the cells of the fluorescent biosensor were encapsulated in alginate hydrogel to develop the cells-alginate hydrogel-based paper.The cells-alginate hydrogel-based paper could detect mercury pollution in 5 min with simple operation process and inexpensive equipment,and it could keep fluorescence and activity stable at 4℃ for 24 hr,which would be a high-throughput screening tool in preliminarily reporting the presence of mercury pollution in natural setting.
基金supported by the National Natural Science Foundation of China (No.50674093)the National Scientific and Technological Support Projects (No.2006BAK03B00) and the Pingdingshan Coal Mine Group
文摘The electromagnetic environment of laneways in underground coal mines is an important area for the design of new electronic products,as well as a fundamental space for mine monitoring,surveillance,communications and control systems.An investigation of electromagnetic interference in coal mines is essential for the enhancement of performances of these systems.In this study,a new field method is provided in which radiated emission tests in coal mine laneways have been carried out.We conclude that:1) the wiring motor vehicles can radiate interference with a bandwidth up to 1 GHz and with an amplitude 10 dBμV/m higher than the background noise;2) the PHS(Personal Handy phone System) mobile communication system can cause interference 40 dBμV/m higher than the background noise;3) an interference 25 dBμV/m higher than the background noise can be generated during the communication at a working bandwidth of 48.8 MHz;and 4) power cables,battery vehicles as well as mechanical and electrical dong rooms have little effect on the electromagnetic radiation environment in coal mine tunnels.
文摘This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview of a certain bridge construction project studied and acoustic non-destructive testing technology and the application of acoustic non-destructive testing technology in actual testing.This analysis hopes to provide some guidelines for acoustic non-destructive testing of modern concrete bridge projects.
基金Supported by the National Natural Science Fundation of China(61174219)
文摘To measure projectile attitude in space flight, based on continuous wave （CW） radar, a new micro-Doppler effect testing technique is developed in this paper. It also establishes radar testing model for attitude of flying projectile and resolve micro-Doppler effect of projectile motion attitude. By distinguishing and geting attitude parameters such as micro-motion period, this technique can in- tuitively estimate the flight stability of projectile, and the validity of this technique is proved accord- ing to flight tests.
文摘Assessment of railway wheel slide protection(WSP) systems involves the execution of complex experimental activities that are quite expensive and time-consuming, since they involve the physical reproduction of degraded adhesion conditions on a real railway line. WSP is devoted to regulating applied braking forces to avoid excessive wheel sliding in case of degraded adhesion conditions between wheel and rail. WSP must be also compliant to safety specifications related to assured braking performances and consumed air. Hardware in the loop(HIL) testing offers an affordable and sustainable way to accelerate these activities optimizing cost, duration and safety of experimental activities performed online. HIL test rigs are subjected to continuous updates, customization and natural ageing of their components. This work investigates the criteria that can be adopted to assure a continuous monitoring and validation of a real WSP test rig, the Italian test rig of Firenze Osmannoro.
文摘This paper describes the use of steady-state solar simulator for CIGS thin-film photovoltaic module hot-spot endurance test. In the study, not only are test procedures of hot-spot endurance test in IEC 61646 discussed, but also how to evaluate the performance of steady-state solar simulator by IEC 60904-9 is presented. Three CIGS thin-film PV modules with the same types are used for hot-spot endurance test in case study. It is found that some of the cell damages and visual defects on tested PV modules are clearly observed.
基金the financial support to the National Natural Science Foundation of China(U20A20279)the technical support provided by Analysis and Test Center of Wuhan University of Science and Technology,China.
文摘Segregation of solute atoms in the center of thick plates of the tempered steel can cause an inhomogeneous structural transformation and generate micron-sized inclusions,which leads to lamellar tearing of thick plate and decreases the plasticity and toughness.The formation and fragmentation mechanisms of micron-sized inclusions,like MnS and(Nb,Ti)C,in the center of thick plates were investigated by using thermodynamic calculations,finite element simulations,and electron backscatter diffraction characterization techniques.The results show that micron-sized inclusions nucleate and grow in the liquid phase,and under tensile loading,they exhibit three fragmentation mechanisms.The local stress during the fragmentation of inclusions is lower than the critical fracture stress of adjacent grains,and phase boundaries can effectively impede crack propagation into the matrix.The existence of a low proportion of high-angle grain boundaries(58.1%)and high Kernel average misorientation value(0.534°)in the segregation band promotes inclusions fragmentation and crack propagation.The difference in crack initiation and propagation direction caused by the morphology of inclusions and physical properties,as well as different matrix arrest abilities,is the main reasons for the diversity of inclusion fragmentation.
文摘In the process of food testing,human operation is an important variable affecting the experimental results.In order to reasonably avoid the influence of human subjective operation behavior on the accuracy of detection results,the laboratory information management system was used as the information platform to design a high-throughput laboratory automation pre-treatment system based on the deep integration of mechanical principles,visual analysis,high-speed conduction,intelligent storage and other technical systems.The experimental results showed that the system could shorten the sample circulation cycle,effectively improve the laboratory biosafety,and meet the requirements of high-throughput processing of samples.
文摘Based on the analysis of food testing standards (according to parameters, categories and methods), this paper puts forward an integrated reference method for food testing standards. At the same time, the innovation of food testing methods puts forward some "normal" requirements from aspects of coverage, recovery rate and consistency with determination standards.
文摘This article presents a real-life project that aimed to evaluate the safety of traffic vehicles on old bridges without any prior data.The project involved various safety inspections,including conventional,static,and dynamic load inspections and safety assessments.After conducting these tests,it was concluded that the structure of the old bridge is relatively safe,with only a few bumps.The bridge could function normally following appropriate treatment.The analysis provides valuable insights into the assessment of the quality and safety of such bridges to ensure the safe driving of heavy vehicles.
文摘This article uses real engineering projects as examples to analyze how static load test technology is applied in testing the bridge-bearing capacity.The analysis covers aspects such as testing section layout,test load and efficiency coefficient,loading plan,evaluation optimization,test result modification,and result evaluation.The aim is to support the accurate detection and evaluation of bridge-bearing capacity.
文摘In order to ensure the healthy growth of agricultural products and provide food for more people, the use of pesticides is essential. If the pesticide residue on food is too much, it will cause certain potential food safety hazard. After eating the food contaminated by the residual agricultural products, the light condition is manifested as dizziness and vomiting, which may lead to poisoning and death. In order to strengthen the detection and identification of pesticide residues in agricultural products, it is necessary to strengthen the supervision and supervision of food safety testing. This article mainly analyzes and discusses the detection technology of pesticide residues in agricultural products and food safety detection for reference.
文摘With the development of the times, people's technology in all walks of life has also improved with the development of the times. Food ranks first in people's needs. Therefore, it is very important whether the food imported meets the regulations and health standards. In order to ensure the production and the health of the crops, people will use pesticides according to the situation during the growth of agricultural products. This will result in pesticide residues that may exist on things. If there are more pesticide residues, there will be potential safety hazards. Generally, symptoms such as dizziness and vomiting will occur after ingesting the pesticide residues. In serious cases, people may be poisoned and killed. Therefore, to strengthen the detection of pesticides in agricultural products has become the focus of attention, and the main direction is to strengthen the supervision and supervision of food safety testing. This article is mainly based on the detection of pesticide residues in agricultural products and food safety testing techniques for analysis and exploration, hoping to provide more advice to the relevant units.
