现代电力电子技术综述

介绍电力电子器件的发展过程,说明电力电子器件的最新发展情况及未来的发展趋势。就现代电力电子技术的应用现状,着重说明其在一般工业及电力系统中的应用。最后介绍电力电子技术未来的发展趋势及应用前景。     

电力电子技术导论

本文介绍了电力电子技术的含义,构成及作用。     

电梯中的电力电子技术

控制系统的改进是电梯的一项关键技术,本文就电力电子技术在电梯中的应用,发展趋势以及PWM控制方法作了简明阐述。     

浅谈电力电子技术的应用及发展方向

介绍了电力电子技术的研究内容,阐述了电力电子技术在电力系统、交通运输、新能源发电、电气节能中的应用情况,并分析了其未来的发展方向。     

电力电子技术导论

本文介绍了电力电子技术的含义,构成及作用.     

Harvest human kinetic energy to power portable electronics

It is known that the human body contains rich chemical energy, part of which is converted to mechanical energy of up to 200W when in motion. Therefore, it is ideal to harvest human body kinetic energy to power mobile electronic devices. This paper presents an energy harvester to unintentionally extract human kinetic energy and directly convert it to electricity, which can serve as a power source for portable electronics. The proposed harvester mainly consists of an eccentric rotor made of permanent magnet, electric steel and coils as stator. The eccentric rotor, as a simple pendulum, acts as the kinetic energy harvester, which can absorb the motion from the human body during walking. With the permanent magnets on the rotor, the moving rotor can produce a changing magnetic field, where electric coils can induce electricity. A torsion spring is also added onto the rotor such that the harvester works even when placed on a horizontal plane where the gravitational acceleration fails. The electromagnetic and kinematical model is built to analyze the performance. Numerical analysis and system optimization are also conducted. Simulation shows that the harvester with 40mm diameter and 50g weight, worn on the wrist, can produce dozens of milliwatts of electricity during normal walking.     

风力发电的现状

世界各国对风电发展高度重视,风电机组单机容量不断扩大,海上风电逐渐发展。风力机组的效率小于0.593。同时简单介绍了现有风力发电机的类型。我国风能资源丰富,随着国家对新能源的重视,出台激励政策,我国风电将有大的发展。     

手足口病的研究概况

人们对手足口病(Hand foot mouth disease,HFMD)的研究已有几十年的历史,全世界已经历了好几次大流行,范围波及许多国家和地区.手足口病病毒有多种亚型,包括oxA5、10、16、19型及EV71型.手足口病疫情的继续和蔓延,不可避免地引起了全世界的恐慌.通过对历史上发生的手足口病、病原体亚型等进行了回顾和统计分析,并初步探讨了其临床表现、诊断、预防和治疗.     

A high voltage pulsed power supply for capillary discharge waveguide applications

We present an all solid-state, high voltage pulsed power supply for inducing stable plasma formation (density ～10(18) cm(-3)) in gas-filled capillary discharge waveguides. The pulser (pulse duration of 1 μs) is based on transistor switching and wound transmission line transformer technology. For a capillary of length 40 mm and diameter 265 μm and gas backing pressure of 100 mbar, a fast voltage pulse risetime of 95 ns initiates breakdown at 13 kV along the capillary. A peak current of ～280 A indicates near complete ionization, and the r.m.s. temporal jitter in the current pulse is only 4 ns. Temporally stable plasma formation is crucial for deploying capillary waveguides as plasma channels in laser-plasma interaction experiments, such as the laser wakefield accelerator.     

钢格板切割的现状与展望分析

随着钢格板在各行业的运用的越来越广泛,目前国内钢格板生主企业普遍使用的用于钢格板切割的圆_盘冷锯机的低效率、大能耗、高耗费、噪音严重的弊端日益呈现.为使钢格板行业的加工水平踏上新的台阶,通过对目前钢格板行业的现状进行分析对比,提出了利用剪切的方法开发高效、节能钢格板剪切机以替代目前使用的圆盘冷锯机的设想.     

A new electric conductance conversion method suitable for very low power applications

This article describes a new electrical conductance converter method suitable for low power applications and an implementation in standard CMOS technology. Despite being designed to meet specific measurements requirements, this converter is intended for applications where device power requirements are determinative such self powered sensors networks and implantable devices. The topology is described and an implementation is presented. Results show the possibility of being powered by a single 1.2 V accumulator cell with a consumption of 8 nJ per conversion.     

原子力显微镜在细胞生物学中应用的现状

原子力显微镜(AFM)是近十几年来表面成像技术最重要的进展之一.AFM具有原子级分辨率,它的产生和发展为细胞生物学研究提供了一种有效的工具.本文介绍原子力显微镜在细胞生物学中应用的现状,包括细胞固定,细胞成像,力检测及细胞操纵,并对原子力显微镜技术的发展进行展望.     

我国电站泵的现状及技术发展趋势

对电站泵的产品分类、产品市场进行了详细分析,同时分析泵行业和电站泵产品的技术现状,指出了泵行业技术发展所面临的严峻局面,最后提出了电站泵五个方面的技术发展趋势,对正确认识电站泵行业的目前现状和今后发展方向有一定的指导意义.