NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a nec...NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a necessary option for the detection of existing exhaust emission standards. At present, there is limited and scattered information on knowledge and test methods of NOx sensors, the research of NOx sensors has become a challenging research topic at home and abroad. Based on these requirements, the article systematically integrates the knowledge of principle and testing methods. First of all, through introducing functional description of NOx sensors and the basic principle of NOx sensors, the relevant scholars can have an overall understanding of the product and master the operation mode of products. Secondly, the current status of performance test bench and methods of NOx sensors were described, which can contribute to having a clear understanding of the development process. After that, a new structure of NOx sensors test bench was purposed, which contains six major units including standard gas source, gas mixing unit, analyzer measurement unit, sensor measurement unit, data processing and display unit, exhaust gas treatment unit. And the test bench was validated. The experimental results show that the test bench has the advantages of high-repeatability, high reliability and low cost. And it can realize automatic detection of multiple target values, which is worthy further promotion. Thereby, the article can contribute to the development of its technology indirectly.展开更多
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
Aflatoxins B1(AFB1)contamination in agro-food holds great threaten to human and animal health.Conventional test strips for rapid AFB1 visualized monitoring remains challenged by improvement of sensitivity and matrix i...Aflatoxins B1(AFB1)contamination in agro-food holds great threaten to human and animal health.Conventional test strips for rapid AFB1 visualized monitoring remains challenged by improvement of sensitivity and matrix interference resistance.In this case,we developed a portable electrochemiluminescence(ECL)imaging test strip with dual-signal outputs for AFB1 quantification in corn samples.RuPEI@SiO_(2)@Au nanospheres were synthesized for bonding with anti-AFB1 antibody and then colorimetrical signal-reported on test line through the capillary flow at strips.Meanwhile,ECL imaging signal of the constructed carbon-ink-based working electrode on polyvinyl chloride substrate of strips was exported under an applied potential of 1.25 V.The whole ECL test strips not only endowed convenient colorimetric responses but guaranteed quick-witted ECL image distinguishment even at extremely low AFB1 content.The detection limit of this ECL imaging-integrated mode was 10-fold lower than that of only colorimetric mode.Furthermore,satisfactory selectivity,reliability and practicability of the as-proposed ECL test strips were demonstrated.This work offered a promising platform for on-site,accurate and sensitive detection of pollutants in foods.展开更多
为了拓展水面防波堤的有效消波周期范围,本文应用Bragg共振,开展多重水面穿透箱体与潜堤组合结构物的消波性能研究。基于时域势流理论,采用去奇异边界元方法(Desingularized Boundary Integral Equation Method,DBIEM),建立数值波浪水槽...为了拓展水面防波堤的有效消波周期范围,本文应用Bragg共振,开展多重水面穿透箱体与潜堤组合结构物的消波性能研究。基于时域势流理论,采用去奇异边界元方法(Desingularized Boundary Integral Equation Method,DBIEM),建立数值波浪水槽,数值计算了规则波与多重等间距布置的水面箱体与水底潜堤组合的结构物之间的相互作用。通过反射系数和透射系数分析了组合结构物的Bragg共振发生点位置、反射强度和消波性能。通过将数值结果与文献数据进行比较,验证了本文数值计算方法的有效性。计算结果给出了透射系数和反射系数随2S/λ(S为相邻结构物的中心间距,λ为入射波长)的变化趋势。结果表明,规则波在多重结构物中传播时会发生Bragg共振,此时其对波浪的衰减效果明显优于单体结构物。对于多重结构物,随着其数量、宽度、水面箱体浸深的增加,Bragg共振反射强度增加,不仅降低了透射系数,而且提升了对长周期波浪的消波能力;而增加相邻组合结构物间隙拓宽了有效消减波浪的周期范围。潜堤的存在加强了防波堤对长周期波的消浪能力。本研究为组合形式的防波堤设计提供参考。展开更多
文摘NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a necessary option for the detection of existing exhaust emission standards. At present, there is limited and scattered information on knowledge and test methods of NOx sensors, the research of NOx sensors has become a challenging research topic at home and abroad. Based on these requirements, the article systematically integrates the knowledge of principle and testing methods. First of all, through introducing functional description of NOx sensors and the basic principle of NOx sensors, the relevant scholars can have an overall understanding of the product and master the operation mode of products. Secondly, the current status of performance test bench and methods of NOx sensors were described, which can contribute to having a clear understanding of the development process. After that, a new structure of NOx sensors test bench was purposed, which contains six major units including standard gas source, gas mixing unit, analyzer measurement unit, sensor measurement unit, data processing and display unit, exhaust gas treatment unit. And the test bench was validated. The experimental results show that the test bench has the advantages of high-repeatability, high reliability and low cost. And it can realize automatic detection of multiple target values, which is worthy further promotion. Thereby, the article can contribute to the development of its technology indirectly.
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financially supported by China Postdoctoral Science Foundation(No.2022T150708)National Key Research and Development Program of China(No.2023YFF1104600)National Natural Science Foundation of China(Nos.32072305,32102089)。
文摘Aflatoxins B1(AFB1)contamination in agro-food holds great threaten to human and animal health.Conventional test strips for rapid AFB1 visualized monitoring remains challenged by improvement of sensitivity and matrix interference resistance.In this case,we developed a portable electrochemiluminescence(ECL)imaging test strip with dual-signal outputs for AFB1 quantification in corn samples.RuPEI@SiO_(2)@Au nanospheres were synthesized for bonding with anti-AFB1 antibody and then colorimetrical signal-reported on test line through the capillary flow at strips.Meanwhile,ECL imaging signal of the constructed carbon-ink-based working electrode on polyvinyl chloride substrate of strips was exported under an applied potential of 1.25 V.The whole ECL test strips not only endowed convenient colorimetric responses but guaranteed quick-witted ECL image distinguishment even at extremely low AFB1 content.The detection limit of this ECL imaging-integrated mode was 10-fold lower than that of only colorimetric mode.Furthermore,satisfactory selectivity,reliability and practicability of the as-proposed ECL test strips were demonstrated.This work offered a promising platform for on-site,accurate and sensitive detection of pollutants in foods.
文摘为了拓展水面防波堤的有效消波周期范围,本文应用Bragg共振,开展多重水面穿透箱体与潜堤组合结构物的消波性能研究。基于时域势流理论,采用去奇异边界元方法(Desingularized Boundary Integral Equation Method,DBIEM),建立数值波浪水槽,数值计算了规则波与多重等间距布置的水面箱体与水底潜堤组合的结构物之间的相互作用。通过反射系数和透射系数分析了组合结构物的Bragg共振发生点位置、反射强度和消波性能。通过将数值结果与文献数据进行比较,验证了本文数值计算方法的有效性。计算结果给出了透射系数和反射系数随2S/λ(S为相邻结构物的中心间距,λ为入射波长)的变化趋势。结果表明,规则波在多重结构物中传播时会发生Bragg共振,此时其对波浪的衰减效果明显优于单体结构物。对于多重结构物,随着其数量、宽度、水面箱体浸深的增加,Bragg共振反射强度增加,不仅降低了透射系数,而且提升了对长周期波浪的消波能力;而增加相邻组合结构物间隙拓宽了有效消减波浪的周期范围。潜堤的存在加强了防波堤对长周期波的消浪能力。本研究为组合形式的防波堤设计提供参考。
