检索结果-南通市图书馆

Sensor Configuration and Test for Fault Diagnoses of Subway Braking System Based on Signed Digraph Method

Chinese Journal of Mechanical Engineering 2014年第3期27卷 475-482页

作者： ZUO Jianyong chen zhongkai Institute of Railway and Urban Mass Transit Tongji University

Fault diagnosis of various systems on rolling stock has drawn the attention of many researchers. However, obtaining an optimized sensor set of these systems, which is a prerequisite for fault diagnosis, remains a major challenge. Available literature suggests that the configuration of sensors in these systems is presently dependent on the knowledge and engineering experiences of designers, which may lead to insufficient or redundant development of various sensors. In this paper, the optimization of sensor sets is addressed by using the signed digraph （SDG） method. The method is modified for use in braking systems by the introduction of an effect-function method to replace the traditional quantitative methods. Two criteria are adopted to evaluate the capability of the sensor sets, namely, observability and resolution. The sensors configuration method of braking system is proposed. It consists of generating bipartite graphs from SDG models and then solving the set cover problem using a greedy algorithm. To demonstrate the improvement, the sensor configuration of the HP2008 braking system is investigated and fault diagnosis on a test bench is performed. The test results show that SDG algorithm can improve single-fault resolution from 6 faults to 10 faults, and with additional four brake cylinder pressure （BCP） sensors it can cover up to 67 double faults which were not considered by traditional fault diagnosis system. SDG methods are suitable for reducing redundant sensors and that the sensor sets thereby obtained are capable of detecting typical faults, such as the failure of a release valve. This study investigates the formal extension of the SDG method to the sensor configuration of braking system, as well as the adaptation supported by the effect-function method.

关键词： fault diagnosis subway braking system signed directed graph sensor set optimization.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Antiskid Control of Railway Train Braking Based on Adhesion Creep Behavior

引用

Chinese Journal of Mechanical Engineering 2012年第3期25卷 543-549页

作者： ZUO Jianyong chen zhongkai Railway and Urban Rail Traffic Academy Tongji UniversityShanghai 200092China

In modern trains wheelset skidding leads to the deterioration of braking behavior,the degradation of comfort,as well as a boost in system *** of the nonlinearity and unknown characteristics of wheelset adhesion,simplifications are widely adopted in the modeling process of conventional antiskid ***,conventional antiskid controllers usually cannot perform *** this paper,systematic computer simulation and field tests for railway antiskid control system are *** operating principal of antiskid control system is explained,which is fundamental to the simulation of antiskid brakes,and the simulation model is introduced,which incorporates both the adhesion creep curve and a pneumatic submodel of antiskid control *** addition,the characteristics of adhesion curves and the simulation target are also *** DHSplus,the pneumatic submodel is created to analyze the performance of the different control strategies of antiskid *** the system simulation is realized by combining the kinematical characteristics of railway trains and the pneumatic *** simulation is performed iteratively to obtain the optimized design of the antiskid control *** design result is incorporated in the hardware design of the antiskid control system and is evaluated in the field tests in Shanghai Subway Line *** by the antiskid efficiency,the antiskid braking performance observed in the field tests shows the superiority of the optimized ***,the proposed simulation method,especially in view of its ease of application,appears to be a useful one for designing railway antiskid control systems.

关键词： antiskid control adhesion creep railway train braking system simulation.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Position Control Optimization of Aerodynamic Brake Device for High-speed Trains

引用

Chinese Journal of Mechanical Engineering 2014年第2期27卷 287-295页

作者： ZUO Jianyong LUO Zhuojun chen zhongkai Institute of Railway and Urban Mass Transit Tongji University

The aerodynamic braking is a clean and non-adhesion braking, and can be used to provide extra braking force during high-speed emergency braking. The research of aerodynamic braking has attracted more and more attentions in recent years. However, most researchers in this field focus on aerodynamic effects and seldom on issues of position control of the aerodynamic braking board. The purpose of this paper is to explore position control optimization of the braking board in an aerodynamic braking prototype. The mathematical models of the hydraulic drive unit in the aerodynamic braking system are analyzed in detail, and the simulation models are established. Three control functions--constant, linear, and quadratic--are explored. Two kinds of criteria, including the position steady-state error and the acceleration of the piston rod, are used to evaluate system performance. Simulation results show that the position steady state-error is reduced from around 12-2 mm by applying a linear instead of a constant function, while the acceleration is reduced from 25,71-3.70 m/s2 with a quadratic control function. Use of the quadratic control function is shown to improve system performance. Experimental results obtained by measuring the position response of the piston rod on a test-bench also suggest a reduced position error and smooth movement of the piston rod. This implies that the acceleration is smaller when using the quadratic function, thus verifying the effectiveness of control schemes to improve to system performance. This paper proposes an effective and easily implemented control scheme that improves the position response of hydraulic cylinders during position control.

关键词： high-speed train aerodynamic brake hydraulic position control optimization.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

ARPES investigation of the electronic structure and its evolution in magnetic topological insulator MnBi2+2nTe4+3n family

引用

National Science Review 2024年第2期11卷 81-93页

作者： Runzhe Xu Lixuan Xu zhongkai Liu Lexian Yang Yulin chen State Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua University School of Physical Science and Technology Shanghai Tech University and CAS-Shanghai Science Research Center Shanghai Tech Laboratory for Topological Physics Frontier Science Center for Quantum Information Collaborative Innovation Center of Quantum Matter Department of Physics Clarendon LaboratoryUniversity of Oxford

In the past 5 years,there has been significant research interest in the intrinsic magnetic topological insulator family compounds MnBi2+2nTe4+3n（where n=0,1,2…）.In particular,exfoliated thin films of MnBi2Te4have led to numerous experimental breakthroughs,such as the quantum anomalous Hall effect,axion insulator phase and high-Chern number quantum Hall effect without Landau ***,despite extensive efforts,the energy gap of the topological surface states due to exchange magnetic coupling,which is a key feature of the characteristic band structure of the system,remains experimentally *** electronic structure measured by using angle-resolved photoemission （ARPES） shows significant deviation from ab initio prediction and scanning tunneling spectroscopy measurements,making it challenging to understand the transport results based on the electronic *** paper reviews the measurements of the band structure of MnBi2+2nTe4+3nmagnetic topological insulators using ARPES,focusing on the evolution of their electronic structures with temperature,surface and bulk doping and film *** aim of the review is to construct a unified picture of the electronic structure of MnBi2+2nTe4+3ncompounds and explore possible control of their topological properties.

关键词： magnetic topological insulator MnBi2Te4 electronic structure angle-resolved photoemission spectroscopy

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

播种期对光温敏无雄穗系玉米花粉育性的影响

引用

湖南农业大学学报（自然科学版） 2024年第2期50卷 12-17页

作者：童博陈种凯吕丹廖志杰郑冉刘雨晴田丰罗红兵湖南农业大学农学院湖南长沙410128 湖南省玉米工程技术研究中心湖南长沙410128 浏阳市农业发展事务中心湖南浏阳410300

为确定光温敏无雄穗系玉米育性转换的生态因子,筛选不育特性稳定的两系材料,选择合适的播期进行制种,以光温敏无雄穗系I17、I478、Ptvt3和Ptvt2为材料,以自交系478、B73为对照,在湖南省浏阳市进行田间分期播种试验,对9个播期玉米的雄花... 详细信息

为确定光温敏无雄穗系玉米育性转换的生态因子,筛选不育特性稳定的两系材料,选择合适的播期进行制种,以光温敏无雄穗系I17、I478、Ptvt3和Ptvt2为材料,以自交系478、B73为对照,在湖南省浏阳市进行田间分期播种试验,对9个播期玉米的雄花育性、雄穗性状、生育期和产量性状等进行分析。结果表明:玉米光温敏无雄穗系育性转换的主要影响因子是苗期的日均高温;I17对环境敏感的时期在V2—V6期间;I478对环境敏感的时期在V2—V4期间;Ptvt3对环境敏感的时期在V2—V4期间;Ptvt2对环境敏感的时期在V2—V5期间;I17适合在播期1、8、9播种,进行自交制种,在第1—6播期播种,作为两系不育系进行杂交种子生产;I478适合在播期1、2、8播种,进行自交制种,在第5—7播期播种,作为两系不育系进行杂交种子生产;Ptvt3适合在播期1、8、9播种,进行自交制种,在第2—7播期播种,作为两系不育系进行杂交种子生产;Ptvt2适合在播期1和播期2播种,进行自交制种,在第3—7播期播种,作为两系不育系进行杂交种子生产。Ptvt3相比I17、I478和Ptvt2具有繁殖产量高、生育期长等优点,且不育特性稳定,适合作为两系不育系进行生产应用。

关键词：玉米光温敏无雄穗播种期花粉育性生育期产量性状

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

胫骨横向骨搬移联合加减桃红四物汤治疗气虚血瘀型糖尿病足的临床疗效观察

引用

中国老年保健医学 2024年第3期22卷 137-140页

作者：陈重凯曾维铨林东刘宇林桂宇蓝文涛刘美锭陈丽明福建中医药大学附属第二人民医院 350003 福建中医药大学附属康复医院 350001

目的观察胫骨横向骨搬移联合加减桃红四物汤治疗糖尿病足的临床疗效。方法本研究采用对照研究,将纳入的44例糖尿病足患者分为对照组和研究组,每组22例。对照组行胫骨横向骨搬移术治疗,研究组在此基础上联合加减桃红四物汤治疗,治疗8周后... 详细信息

目的观察胫骨横向骨搬移联合加减桃红四物汤治疗糖尿病足的临床疗效。方法本研究采用对照研究,将纳入的44例糖尿病足患者分为对照组和研究组,每组22例。对照组行胫骨横向骨搬移术治疗,研究组在此基础上联合加减桃红四物汤治疗,治疗8周后,观察对比两组患者中医证候积分、患足皮温、踝肱指数、足背动脉血流动力学指标以及临床疗效变化。结果与治疗前相比两组患者中医证候积分、患足皮温、踝肱指数、血管内径及血流流速均较治疗前显著升高(P0.05);研究组临床疗效总有效率为90.91%,显著高于对照组的总有效率为72.73%(P<0.05)。结论加减桃红四物汤联合胫骨横向骨搬移治疗,可以提高糖尿病足临床疗效。

关键词：桃红四物汤胫骨横向骨搬移糖尿病足

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enabling superior electrochemical performance of NCA cathode in Li_(5.5)PS_(4.5)Cl_(1.5)-based solid-state batteries with a dual-electrolyte layer

引用

Chinese Chemical Letters 2024年第4期35卷 231-236页

作者： Ziling Jiang Shaoqing chen Chaochao Wei Ziqi Zhang zhongkai Wu Qiyue Luo Liang Ming Long Zhang Chuang Yu School of Chemistry and Chemical Engineering Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China Innovation Center for Chemical Sciences College of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China College of Physics and Energy Fujian Normal UniversityFuzhou 350117 China

LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA) is a promising cathode for sulfide-based solid-state lithium batteries(ASSLBs)profiting from its high specific capacity and voltage plateau, which yielding high energy density. However, the inferior interfacial stability between the bare NCA and sulfides limits its electrochemical performance. Hereien, the dual-electrolyte layer is proposed to mitigate this effect and enhance the battery performances of NCA-based ASSLIBs. The Li_(3)InCl_6 wih high conductivity and excellent electrochemcial stability act both as an ion additives to promote Li-ion diffusion across the interface in the cathode and as a buffer layer between the cathode layer and the solid electrolyte layer to avoid side reactions and improve the interface stability. The corresponding battery exhibits high discharge capacities and superior cyclabilities at both room and elevated temperatures. It exhibits discharge performance of 237.04 and216.07 m Ah/g at 0.1 and 0.5 C, respectively, when cycled at 60 ℃, and sustains 95.9% of the capacity after100 cycles at 0.5 C. The work demonstrates a simple strategy to ensure the superior performances of NCA in sulfide-based ASSLBs.

关键词： LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2) Li_(5.5)PS_(4.5)Cl_(1.5) Double solid electrolyte layer configuration Operating temperatures Electrochemical performances

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Percutaneous closure of left internal mammary artery-to-pulmonary artery fistula using the domestic vascular plug:a case report

引用

Journal of Medical Colleges of PLA(China) 2010年第4期25卷 247-251页

作者： chen Shaoping Wang zhongkai Zhao Xianxian Qin Yongwen Department of Cardiology Changhai Hospital Second Military Medical University Shanghai 200433 China

A 55-year-old man was admitted for transcatheter closure because of pulmonary arteriovenous fistula by magnetic resonance angiography （MRA）. He had a history of occasional chest pain more than one year. Angiography didn＇t reveal significant stenosis at coronary artery. The patient was found a continuous grade 2/6 murmur over the left upper parastenal area one month ago. Chest MRA revealed a possible left superior pulmonary arteriovenous fistula. For diagnosis and localization of the fistula, aortography and selective angiography of the intemal mammary artery was performed and presented a left internal mammary artery-to-pulmonary artery fistula. The fistula was successfully closed using an 12 mm domestic vascular plug. Chest MRA showed that the fistula disappeared at two-month follow-up

关键词： Intemal mammary artery-to-pulmonary artery fistula Transcatheter closure Vascular plug

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A wideband,high-resolution vector spectrum analyzer for integrated photonics

引用

Light(Science & Applications) 2024年第4期13卷 760-771页

作者： Yi-Han Luo Baoqi Shi Wei Sun Ruiyang chen Sanli Huang zhongkai Wang Jinbao Long chen Shen Zhichao Ye Hairun Guo Junqiu Liu International Quantum Academy 518048 ShenzhenChina. Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology518055 ShenzhenChina. Department of Optics and Optical Engineering University of Science and Technology of China230026 HefeiChina. Hefei National Laboratory University of Science and Technology of China230088 HefeiChina. Qaleido Photonics 518048 ShenzhenChina. Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai University200444 ShanghaiChina

The analysis of optical spectra—emission or absorption—has been arguably the most powerful approach for discovering and understanding *** invention and development of many kinds of spectrometers have equipped us with versatile yet ultra-sensitive diagnostic tools for trace gas detection,isotope analysis,and resolving hyperfine structures of atoms and *** proliferating data and information,urgent and demanding requirements have been placed today on spectrum analysis with ever-increasing spectral bandwidth and frequency *** requirements are especially stringent for broadband laser sources that carry massive information and for dispersive devices used in information processing *** addition,spectrum analyzers are expected to probe the device’s phase response where extra information is *** we demonstrate a novel vector spectrum analyzer(VSA)that is capable of characterizing passive devices and active laser sources in one *** a dual-mode VSA can measure loss,phase response,and dispersion properties of passive *** also can coherently map a broadband laser spectrum into the RF *** VSA features a bandwidth of 55.1 THz(1260–1640 nm),a frequency resolution of 471 kHz,and a dynamic range of 56 ***,our fiber-based VSA is compact and *** requires neither high-speed modulators and photodetectors nor any active feedback ***,we employ our VSA for applications including characterization of integrated dispersive waveguides,mapping frequency comb spectra,and coherent light detection and ranging(LiDAR).Our VSA presents an innovative approach for device analysis and laser spectroscopy,and can play a critical role in future photonic systems and applications for sensing,communication,imaging,and quantum information processing.

关键词： spectrum resolution coherent

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Decoding the fish genome opens a new era in important trait research and molecular breeding in China

引用

Science China Life Sciences 2024年第10期67卷 2064-2083页

作者： Qian Zhou Jialin Wang Jiongtang Li Zhangfan chen Na Wang Ming Li Lei Wang Yufeng Si Sheng Lu zhongkai Cui Xuhui Liu Songlin chen State Key Laboratory of Mariculture Biobreeding and Sustainable Goods Yellow Sea Fisheries Research InstituteChinese Academy of Fishery Sciences Laboratory for Marine Fisheries Science and Food Production Processes Qingdao Marine Science and Technology Center Key Laboratory of Aquatic Genomics Ministry of Agriculture and Rural AffairsBeijing Key Laboratory of Fishery BiotechnologyChinese Academy of Fishery Sciences

Aquaculture represents the fastest-growing global food production sector, as it has become an essential component of the global food *** has the world's largest aquaculture industry in terms of production volume. However, the sustainable development of fish culture is hindered by several concerns, including germplasm degradation and disease outbreaks. The practice of genomic breeding, which relies heavily on genome information and genotypephenotype relationships, has significant potential for increasing the efficiency of aquaculture production. In 2014, the completion of the genome sequencing and annotation of the Chinese tongue sole signified the beginning of the fish genomics era in China. Since then, domestic researchers have made dramatic progress in functional genomic studies. To date, the genomes of more than 60 species of fish in China have been assembled and annotated. Based on these reference genomes, evolutionary, comparative,and functional genomic studies have revolutionized our understanding of a wide range of biologically and economically important traits of fishes, including growth and development, sex determination, disease resistance, metamorphosis, and pigmentation. Furthermore, genomic tools and breeding techniques such as SNP arrays, genomic selection, and genome editing have greatly accelerated genetic improvement through the incorporation of functional genomic information into breeding activities. This review aims to summarize the current status,advances, and perspectives of the genome resources, genomic study of important traits, and genomic breeding techniques of fish in *** review will provide aquaculture researchers, fish breeders, and farmers with updated information concerning fish genomic research and breeding technology. The summary will help to promote the genetic improvement of production traits and thus will support the sustainable development of fish aquaculture.

关键词： fish genomics economic traits genomic selection genome editing genomic breeding

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：