Soft-switching Analysis Phase-Shifted-FB-ZVS-PWM DC-DC Converter With Saturable Inductor     

DU Jun~  ZHOU Luo-wei~  LU Zhi-guo~ 《保鲜与加工》2004,(1):53-57

Compared with the traditional full-bridge(FB)zero-voltage-switched(ZVS) pulsewidth-modulated(PWM) converter, the FB-ZVS-PWM converter with a saturable inductor has a wider load range with ZVS and smaller circulating energy as well as smaller duty cycle loss. By analyzing the operation principle of the converter, this paper studies design considerations of the parameter bringing about ZVS and dead time of the switch, and gives out the design method, finally simulation testing has been carried out.  相似文献   

Real-time Vehicle Scheduling     

ZHANG Si fu  GUAN Shi ping  ZHANG Shun ping  DUN Xiao peng 《保鲜与加工》2002,(10):49-51

The traditional scheduling for vehicle is option in the fixed network. But it can't satisfy the real time environment. The demand of order is changeable and uncertain in real environment. It is convenient for scheduling transforming it into static data, but can't get the advantage on time. This paper proposes a real time vehicle scheduling on the study of traditional scheduling and discusses the model structure and the key technology for the real time system that establishes the base for develop teal time system.  相似文献   

Simulation Propagation of Partial Discharge UHF Signals in Transformer     

MENG Yan-hui  TANG Ju  XU Zhong-rong  ZHANG Xiao-xing  HU Jing-jing 《保鲜与加工》2007,(5):70-74

Many factors affect the propagation of ultra high frequency(UHF) signals caused by partial discharge(PD) on the waveforms and energy of signals in transformer.To investigate the relationshi Pof factors and UHF signals,simulation model of transformer for PD study are established.UHF signals in simulation model of transformer caused by PD are calculated using finite difference time domain method.By means of amplitude and cumulative energy plot of simulation signals,and combing the measured result,the following factors:distance between PD source and detection position,different metallic conductor position around detection position and iron core and winding are researched,which contribute to comprehend the propagation characteristic of UHF signals and detect UHF signals accurately.  相似文献   

Multi-channel and High Precise Time Relay Verification Instrument     

LUO Jun  SU Ji-wen  CHENG Jie 《保鲜与加工》2004,(12):24

  相似文献   

Summarization of Current Research on Application of Durability of Structures     

LI Hong yi  CHEN Zhao hui  BAI Shao liang  XIANG Chang kui 《保鲜与加工》2001,(2):98-103

This paper summarized the recent research results about the durability of structures, introduced their current application in durability design, appraisal, estimation of rest life and strategy of maintenance and strengthening as well as in other fields.  相似文献   

The Monitoring Measurements and Country Rock Control of NATM in Tunnel of Express Road during Construction     

Liu Li Tang Janxin 《保鲜与加工》1995,(5):113-119

In this paper the author' s study on the monitoring measurement technique of NATM,the regularity and conditions of the country rock deformation are analysed based on the site measurement data in the west section of Zhongliangshan tunnel. The regression analysis of measure data for different measure lines of vavious country rock is done by the use of self-compiled CRAP program. The stability criterion for various rockmass and optimum time for primary and permanent support are provided. The conclusion available could conduct the theoretical research of NATM deeply as well as tunnel design and construction.  相似文献   

THE INDUSTRIAL ORGANIZATIONS AND THE L-S-BUSINESS STRATEGIES     

He Zonglu 《保鲜与加工》1992,(4):111-117

This papar presents an evolution model in business behaviors-the L-S Business Strategies,gives some examples and predictions which support these strategies,and analyzes the relationship between the industrial organizations in China and the L-S Business strategies.  相似文献   

双向电泳技术研究及其在农业生物蛋白质组学研究中的应用     

刘伟霞  潘映红 《中国农学通报》2007,23(6):89-89

双向电泳技术在蛋白质组学研究领域中处于核心地位。从样品制备、第一向等电聚焦电泳及第二向SDS-聚丙烯酰胺凝胶电泳、蛋白检测等关键环节方面对双向电泳技术的研究进展作了详细综述，并简要分析评价了以经典双向电泳为基础发展起来的差异凝胶电泳；同时重点介绍了双向电泳技术在农业生物蛋白质组学研究领域中的应用范围，为进一步开发利用提供参考；最后对双向电泳技术的发展前景作了展望。  相似文献   

The Method of Diagnosing Brain-dysfunction Based on Membership Function and BP Neural Network     

Zeng Xiaoping  Zou Jiaqi  Zang Anbang 《保鲜与加工》1996,(3):44-49

Membership functions.formed with the characteristic values obtained by applying the continuous reaction time (CRT) theory from controls and heptic encephalopthy and proposedin this paper.whith these membership functions,the CRT data to be diagnosed are calculated in advance,and then discriminated by BP meural network to differentiate patients with or without braindysfunction.The troubles of low accuracy and efficiency,encountered in training BP network withfuzzy samples.scattered data and extended samples,are solved.  相似文献   

基于LS-SVM的小水电站年发电量智能预测模型     

吴德会  虞耀君 《中国农村水利水电》2007,(2):93-95,98

针对小水电站年发电量序列的特点,将最小二乘支持向量机(least squares support vector machine,LS-SVM)回归模型引入年发电量预测领域,并给出了相应的过程和算法。与常规基于人工神经网络(artificial neural net-works,ANN)的智能预测方法比较,该模型优点是明显的:①将神经网络迭代学习问题转化为直接求解多元线性方程;②整个训练过程中有且仅有一个全局极值点,确定了预测的稳定性。最后,一个实际的预测例子表明:该模型实现容易、预测准确,适用于小水电站预测。  相似文献