检索结果-南通市图书馆

An Algorithm for Short-Circuit Current Interval in Distribution Networks with Inverter Type Distributed Generation Based on Affine Arithmetic

在线全文

学校读者我要写书评

暂无评论

Energy engineering 2024年第7期121卷 1903-1920页

作者： Yan Zhang Bowen Du Benren Pan GuannanWang Guoqiang xie Tong Jiang Electric Power Research Institute State Grid Jiangxi Electric Power Co.Ltd.Nanchang330096China school of electrical and Electronic engineering North China Electric Power UniversityBeijing102206China

During faults in a distribution network,the output power of a distributed generation(DG)may be ***,the output currents of distributed power sources are also affected by the output power,resulting in uncertainties in the calculation of the short-circuit current at the time of a ***,the impacts of such uncertainties around short-circuit currents will increase with the increase of distributed power ***,it is very important to develop a method for calculating the short-circuit current while considering the uncertainties in a distribution *** this study,an affine arithmetic algorithm for calculating short-circuit current intervals in distribution networks with distributed power sources while considering power fluctuations is *** proposed algorithm includes two *** the first stage,normal operations are considered to establish a conservative interval affine optimization model of injection currents in distributed power *** by the fluctuation range of distributed generation power at the moment of fault occurrence,the model can then be used to solve for the fluctuation range of injected current amplitudes in distributed power *** second stage is implemented after a malfunction *** this stage,an affine optimization model is first *** model is developed to characterizes the short-circuit current interval of a transmission line,and is constrained by the fluctuation range of the injected current amplitude of DG during normal ***,the range of the short-circuit current amplitudes of distribution network lines after a short-circuit fault occurs is *** algorithm proposed in this article obtains an interval range containing accurate results through interval *** with traditional point value calculation methods,interval calculation methods can provide more reliable analysis and calculation *** range of short-circuit current amplitude ob

关键词： Short circuit calculation inverter type distributed power supplies affine arithmetic distribution network

Study on frictional behavior of SiC_(f)/SiC composite clad tube clamping condition under nuclear irradiation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第5期12卷 919-938页

作者： Chenglong XIAO Liangliang SHEN Tianqi ZHU Jianbo TANG Ximing xie Xinyu FAN Jian XU Zhiying REN school of mechanical engineering Zhejiang University of TechnologyHangzhou310023China engineering Laboratory of Advanced Energy Materials Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo315201China State Key Laboratory of Fine Chemicals Liaoning High-Performance Polymer Engineering Research CenterSchool of Chemical EngineeringDalian University of TechnologyDalian116024China school of mechanical engineering and Automation Fuzhou UniversityFuzhou350116China school of Computer Science and technology Shandong UniversityQingdao266237China Aviation Industry Corporation of china Ltd.Beijing100028China

Silicon carbide fiber reinforced silicon carbide matrix(SiC_(f)/SiC)composite is the key cladding material of nuclear fuel,which determines the safety and reliability of nuclear fuel storage and *** replacement of its storage and transportation scenario needs to be completed by the manipulator,but the application of SiC_(f)/SiC wear,fracture,and nuclear leakage in the snatching process of brittle-flexible-rigid contact in the irradiation environment has been seriously restricted due to unclear understanding of the damage ***,the effects of irradiation dose and clamping load on the friction characteristics of the contact interface between SiC_(f)/SiC clad tube are studied in this paper,and the effects of irradiation parameters and clamping force on the static friction coefficient of the contact interface between the clad tube and flexible nitrile are *** on the Greenwood-Williamson tribological model,a numerical model of the shape and structure of the contact micro-convex at the micro-scale of the clamping interface is constructed by introducing the multi-surface integral,and finally verified by *** research results show that there is a unique“Irradiation suppression zone”under the clamping condition of SiC_(f)/SiC cladding tube under the nuclear irradiation environment,and the growth of static friction coefficient slows down until stagnates after irradiation reaches a certain extent(600 kGy),and there will be a decline when the irradiation dose continues to increase,among which the clamping force of 15.2 N within the irradiation interval of 1,000 kGy can meet the safety of nuclear environment *** results of this paper can provide an important theoretical basis and application guidance for the safe operation of SiC_(f)/SiC cladding tubes in the storage and transportation clamping process.

关键词： SiC_(f)/SiC Clad tube nuclear irradiation conditions Greenwood-Williamson tribological model multi-surface integral

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

一种基于最优控制的车队协作算法

上海交通大学学报 2011年第7期45卷 949-953页

作者：谢强德杨明王冰王春香上海交通大学电子信息与电气工程学院上海200240 上海交通大学机械与动力工程学院上海200240

为缩短车队通过路口的时间,提出了一种基于最优控制的车队协作算法.首先,根据车辆运动的物理关系构建车队模型,并利用包含原理对其进行分解,获得车队系统的扩展模型.然后,使用最优输出跟踪控制算法,并根据车队安全性要求求取算法中的权... 详细信息

为缩短车队通过路口的时间,提出了一种基于最优控制的车队协作算法.首先,根据车辆运动的物理关系构建车队模型,并利用包含原理对其进行分解,获得车队系统的扩展模型.然后,使用最优输出跟踪控制算法,并根据车队安全性要求求取算法中的权重矩阵,得到车队系统的最优控制率.最后,通过收缩原系统获得车队的次优控制率.该方法可以在保证车辆安全行驶情况下,使车队能尽快达到目标巡航速度,从而快速通过路口.仿真和实际实验结果证明了该方法的有效性.

关键词：最优控制车队重叠结构分解仿真

Weibull Distribution Parameters for Fault Feature Extraction of Rolling Bearing

在线全文

学校读者我要写书评

暂无评论

Weibull Distribution Parameters for Fault Feature Extraction...

Lattice dynamics and thermoelectric properties of diamondoid materials

2011 Chinese Control and Decision Conference（CCDC）

作者： PENG Tao is with the school of Information Science and engineering,Changsha,410083 china.Also,she is with the College of Automatic Control,Beijing Institute of technology,Beijing,100081 china.JIANG Haiyan is with the College of electrical engineering,Hunan university of technology,Zhuzhou,412008 china .xie Yong is with the College of electrical engineering,Hunan university of technology,Zhuzhou,412008 china .

A novel approach to fault feature extraction using Weibull distribution parameters is *** the original signal of bearing vibration is modeled as the Weibull distribution,its scale parameter is extracted as a new feature vector for the bearing running *** tests results of fault diagnosis of the rolling bearing verify that this new feature can catch the regularity of changes in the information of bearing vibration more sensitively and accurately,and have higher separability suitable for pattern recognition by support vector machine classifier.

关键词： Weibull Distribution Scale Parameter Feature Extraction Fault Diagnosis Rolling Bearing

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Interdisciplinary Materials 2024年第1期3卷 5-28页

作者： Hongyao xie Li‐Dong Zhao Mercouri G.Kanatzidis school ofMaterialsScienceand engineering BeihangUniversityBeijingChina Department ofChemistry Northwestern UniversityEvanstonIllinoisUSA

The diamondoid compounds are a large family of important semiconductors,which possess various unique transport properties and had been widely investigated in the fields of photoelectricity and nonlinear *** a significantly long period of time,diamondoid materials were not given much attention in the field of ***,this changed when a series of diamondoid compounds showed a thermoelectric figure of merit(ZT)greater than *** discovery sparked considerable interest in further exploring the thermoelectric properties of diamondoid *** review aims to provide a comprehensive view of our current understanding of thermal and electronic transport in diamondoid materials and stimulate their development in thermoelectric *** present a collection of recent discoveries concerning the lattice dynamics and electronic structure of diamondoid *** review the underlying physics responsible for their unique electrical and phonon transport ***,we provide insights into the advancements made in the field of thermoelectricity for diamondoid materials and the corresponding strategies employed to optimize their ***,we emphasize the challenges that lie ahead and outline potential avenues for future research in the domain of diamondoid thermoelectric materials.

关键词： diamondoid compounds electronic properties thermal conductivity thermoelectric materials

Cardiac Piezo1 Exacerbates Lethal Ventricular Arrhythmogenesis by Linking mechanical Stress with Ca^(2+) Handling After Myocardial Infarction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2024年第1期2023卷 583-594页

作者： Sheng-an Su Yuhao Zhang Wudi Li Yutao Xi Yunrui Lu Jian Shen Yuankun Ma Yaping Wang Yimin Shen Lan xie Hong Ma Yao xie Meixiang Xiang Department of Cardiology Cardiovascular Key Laboratory of Zhejiang ProvinceThe Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009China Department of Endocrinology The Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009China Texas Heart Institute HoustonTX 77030USA

Ventricular arrhythmogenesis is a key cause of sudden cardiac death following myocardial infarction(MI).Accumulating data show that ischemia,sympathetic activation,and inflammation contribute to ***,the role and mechanisms of abnormal mechanical stress in ventricular arrhythmia following MI remain *** aimed to examine the impact of increased mechanical stress and identify the role of the key sensor Piezo1 in ventricular arrhythmogenesis in *** with increased ventricular pressure,Piezo1,as a newly recognized mechano-sensitive cation channel,was the most up-regulated mechanosensor in the myocardium of patients with advanced heart ***1 was mainly located at the intercalated discs and T-tubules of cardiomyocytes,which are responsible for intracellular calcium homeostasis and intercellular communication.

关键词： ventricular homeostasis Ventricular

Design of an Inference Engine Based on BP Network and LabVIEW

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

微计算机信息 2008年第31期24卷 297-299页

作者： WANG Ju-quan LIN Fu-sheng SHENG Hong-fei MENG Guan(school of electrical & mechanical engineering,Wuhan Uni-versity of Science and engineering, Wuhan, 430073)(school of mechanical Science & engineering,Huazhong Uni-versity of Science & technology, Wuhan, 430074)(State Key Laboratory of mechanical System and Vibration,Shanghai Jiao Tong university, Shanghai, 200240)

In the field of engineering, LabVIEW and MATLAB are the languages most commonly used by program developers. Howev-er, they have their respective advantages and disadvantages. The combination of the two will undoubtedly facilitate program develop-ment. Design of inference engine is the key point and difficulty in the design of fault diagnosis expert system. This paper combinesLabVIEW and MATLAB to design the inference engine of fault diagnosis expert system based on the advantages of the graphical pro-gramming environment and signal analysis toolkit of LabVIEW without the defect of neural network toolkit. In addition, it introducesthe implementation methods and precautions for combination of LabVIEW and BP network so as to make LabVIWE amd BP benefitfrom each other, which is of great pragmatic value.

关键词： BP神经网络计算机技术程序设计结构设计

Optimization of Processing Parameters for Laser Powder Deposition using Finite Element Method

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of technology(Materials Science) 2010年第5期25卷 832-837页

作者：付垚 State Key Laboratory of Non-ferrous Metals and Processes General Research Institute for Non-ferrous Metals

In order to investigate the effects of powder materials and processing parameters on thermal and stress field during laser powder deposition （LPD）, a finite element model was developed with the help of ANSYS software. The finite element model was verified by the comparison between the experimental results and computed results. Then LPD processes with different powder materials and processing parameters were simulated by using the FE model. The results show that less difference of thermal conductivity and thermal expansion coefficient between powder material and substrate material produces lower residual stress; higher laser power, laser scanning speed and smaller laser beam diameter can lead higher peak temperature and higher residual stress. The research opens up a way to rational selection of the powder materials and processing parameters for ensured quality.

关键词： laser powder deposition thermal field stress field powder material processing parameters

Anisotropic shearing mechanism of Kangding slate:Experimental investigation and numerical analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical engineering 2024年第5期16卷 1487-1504页

作者： Ping Liu Quansheng Liu Penghai Deng Yucong Pan Yiming Lei Chenglei Du Xianqi xie The Key Laboratory of Geotechnical and Structural engineering Safety of Hubei Province School of Civil EngineeringWuhan UniversityWuhan430072China State Key Laboratory of Water Resources and Hydropower engineering Science Wuhan UniversityWuhan430072China

The shear mechanical behavior is regarded as an essential factor affecting the stability of the surrounding rocks in underground *** shear strength and failure mechanisms of layered rock are significantly affected by the foliation *** shear tests were conducted on cubic slate samples with foliation angles of 0°,30°,45°,60°,and 90°.The effect of foliation angles on failure patterns,acoustic emission(AE)characteristics,and shear strength parameters was *** on AE characteristics,the slate failure process could be divided into four stages:quiet period,step-like increasing period,dramatic increasing period,and remission period.A new empirical expression of cohesion for layered rock was proposed,which was compared with linear and sinusoidal cohesion expressions based on the results made by this paper and previous *** comparative analysis demonstrated that the new expression has better prediction ability than other *** proposed empirical equation was used for direct shear simulations with the combined finite-discrete element method(FDEM),and it was found to align well with the experimental *** both computational efficiency and accuracy,it was recommended to use a shear rate of 0.01 m/s for FDEM to carry out direct shear *** balance the relationship between the number of elements and the simulation results in the direct shear simulations,the recommended element size is 1 mm.

关键词： Anisotropy Empirical expression of cohesion foliation angles Combined finite-discrete element method(FDEM) Shear rate Element size