查询词典 electric resistance

The importance of Gauss theorem in electrostatics;the relation between electric flux and electric intensity; the notes of finding intensity of electric field by Gauss theorem ; the rules of choosing Gaussian plane and the relation between the intensity of electric field on Ganssian plane and space-charge.

高斯定理在静电学中的重要性，用高斯定理求电场强度注意的问题，取高斯面的原则及高斯面上的电场强度与空间电荷的关系。

From the view of torque controlling strategy, the relation between the torque controlling strategy such as the electric current feedback method、 PWM open loop method etc and the vehicle driving way is analyzed firstly, then the conclusion could be drawn that the PWM open loop method has more advantages than the electric current feedback method when they are both used in the same vehicle which is direct driving by hubcap motor. Secondly, based on the electric motor mathematic model and its experiment, a new permanent brushless dc motor phase electric current detector method in which a digital signal processor and single current sensor are used is introduced.

从转矩控制策略角度来看，分析了电流反馈法以及开环PWM电压调速控制方法与车辆的驱动方式关系，得出了电机驱动电压受限的情况下，无论是从对车辆的动力性能影响还是从对车辆的驱动要求来讲，开环PWM电压调速控制方法较电流反馈法更适用于以轮毂电机直接驱动方式的两轮电动车中；其次，根据电机的数学模型以及电机试验波形，提出了一种利用数字信号处理器以及单个电流传感器检测三相永磁无刷电机电枢电流的新方法，这种方法具有较强的适应性、实时性，它可以根据控制系统的要求，适时地提供所需电流数据，是目前许多文章关于无刷电机相电流平波的重要技术基础。

Taking the electric power design institutes over the country as firm technological support,our Company is the specialized manufacturer specializing in material transport products such link electric drive pusher series,aligning roller series,groov eelectric drive plough,wiper,electric drive anti-sticking T-cock,buffer air lock of new generation,electric drive buffer roll,buffer device,double-arm feeder,coal-covered curtain,gathering sill,belt head retractor,sprinkler,winding irrigator and so on,which are widely used in domestic thermal power plant,colliery,harbor,chemical and metallurgical industry.

本公司以全国各电力设计院为坚强的技术作后盾，是专业生产电动推杆系列，调心托辊系列，槽角电动犁式卸料器，刮水器，电动防卡三通，新一代缓冲锁气器，电动缓冲滚筒，缓冲装置，双推杆给料机，挡煤帘，导料槽，皮带头部伸缩装置，洒水器，卷绕冲洗器等物料输送产品的专业生产厂家。广泛应用于国内火电厂、煤矿、港口、化工、冶金等行业。

Is 1000 ℃ diagraph scopes to 0~, adoption thermocouple, such as Nie chrome thermocouple, cent degree is an EU, it outputs the signal as 0~41.32 mVs, is changed to send a machine by milli- Fu, output a 0~10 mas, then convert into the 0~5 V electric voltage signal after the electric current-electric voltage transformation electric circuit.

对于0~1000℃的测量范围，采用热电偶，如镍铬热电偶，分度号为EU，其输出信号为0~41.32mV，经毫伏变送器，输出0~10mA，然后再经过电流——电压变换电路转换为0~5V电压信号。

The technology of electric information is developing very fast and make much more and more electric products teem,which develop in the direction of handy and miniaturization,such as mordern times communication equipmen、handy electric product、luggable computer、electric car、moonlet,and so on.it is used at large that the power supply make use of storage battery.hower most of storage battery can but use appropriative chargers,that need long time in the electrification and can't judge the electrification parameter and spare electrification time.thus it need a have much function and handy intelligent charger device that is a far-ranging application different kinds and types.the text integrate upwards request that will introduce a device and system of intelligent charger base on singlechip.in the power supply loop,the transformer take the voltage from 220v to 12v,then the rectifier circuit take the voltage turn to 14v,it is by way of the voltage of electrification power supply.

内容提要：电子信息技术的快速发展使得各种各样的电子产品不断涌现，并朝着便携和小型轻量化的趋势发展，现代通讯设备、便携式电子产品、笔记本电脑、电动汽车、小卫星等普遍使用蓄电池作为电源，应用非常广泛。然而大多数设备中的蓄电池，只能使用专用的充电器，而且普通的充电器大多充电时间长，无法判断其充电参数和剩余的充电时间，那么就需要一种广泛应用于不同种类和型号的可知道其充电参数和剩余充电时间的多功能便携式通用智能充电设备。本文结合以上要求介绍一种基于单片机的通用智能充电器的设计。

Has specialized in producing all kinds of forest vacuum cup, heat pot, beer mug, gift cup, plastic cup, USB electric auto mug, electric coffee mixing mug, coffee cup, coffee pot, electric coffee grinder, electric coffee pot, stainless steel vacuum pressure pots, office cup, vacuum lunch boxes, glass, bachelor cup, promotion cup,迪斯尼米奇cup, advertising cup, sports mug, sport pot, brewing cup, teacup, water, appropriate health cups, nano-cup, readily Cup , ceramic cups, small wine pot, plastic pepper mill, stainless steel soap, Shaker, sealed cans, thermal cup, color changing cups, food container, etc.!

浙江有林工贸有限公司专业生产各种真空杯，保温壶，啤酒杯，礼品杯，塑料杯，USB 电热汽车杯，电动咖啡搅拌杯，咖啡杯，咖啡壶，电动咖啡磨，电热咖啡壶，不锈钢真空气压壶，办公杯，真空饭盒，玻璃杯，学士杯，促销杯，迪斯尼米奇杯，广告杯，运动杯，运动壶，冲泡杯，压茶杯，水宜生杯，纳米杯，随手杯，陶瓷杯，小酒壶，塑料胡椒磨，不锈钢肥皂，摇酒器，密封罐，热敏杯，变色杯，保鲜盒等！

In this topic, the dynamic analysis methods for piezoelectric vibrator are studied systematically based on the theoretical model, FEM numerical experimentation and FEM governing equation for given compound-mode vibrator, and some valuable conclusions are obtained. The main work accomplished is summarized as follows: 1.Elaborate the main modeling methods for piezoelectric vibrator and the significance and necessity to study the dynamic characteristics of piezoelectric vibrator which emphasize the urgency of this paper. 2.Take the bending deformation induced by piezoelectric ceramic as example, the energy transfer mechanism of electric energy to mechanical energy are analyzed; the motion and force transfer mechanism are analyzed for the longitudinal-bending vibrator. 3.Based on mode assumption and Hamilton principle, the coupling model of piezoelectric vibrator of linear USM is built; moreover, the equivalent circuit model is obtained and a coupling equation represents the relation between electric parameters and mechanical parameters is derived which provides foundation to match the vibrator and driving circuit. 4.Combine the constitutive equation of piezoelectric ceramic with elastic-dynamical equation, geometric equation in force field and the Maxwell equation in electric field and the corresponding boundary condition equation, the FEM control equation for piezoelectric vibrator of USM to solve dynamic electro-mechanical coupling field is established by employing the principle of virtual displacement. The equation lays the foundation to study the non-linear constitutive equation of piezoelectric ceramic driven by high-power. 5.Define the dynamic indexes of characteristic of vibrator and carry out variable parameters simulation by calculating the model parameters and the electric characteristics of vibrator are simulated according to the equivalent circuit model. By numerical experimentation, the working mode of vibration of vibrator and the shock excitation results of the working frequency band which provides the mode frequency to realize bimodal are analyzed. Detailed calculation of the electro-mechanical coupling field parameters is made by programming the FEM control equation.

本课题从理论模型、有限元数值试验、有限元控制模型等方面以复合振动模式振子为例对超声电机压电振子的动力学特性及其分析方法进行了全面系统地研究，得出了许多有价值的结论，主要概括如下： 1、阐述了目前针对超声电机压电振子的主要建模方法，对压电振子动态特性的研究意义和必要性进行了论述，突出了本文研究内容的迫切性； 2、以压电陶瓷诱发弹性体发生弯曲变形为例，分析了压电陶瓷通过诱发应变来实现机电能量转换的机理；对基于纵弯模式的压电振子的运动及动力传递机理进行了分析； 3、基于模态假定，利用分析动力学的Hamilton原理，建立了面向直线超声电机压电振子的机电耦合动力学模型，并据此建立了压电振子的等效电路模型，导出了电参量与动力学特性参量的耦合方程，为压电振子与驱动电路的匹配提供了依据； 4、从压电陶瓷的本构方程出发，综合力场的弹性动力学方程、几何方程、电场的麦克斯韦方程以及相应的边界条件方程，采用虚位移原理，建立了压电振子动态问题机电耦合场求解的有限元控制方程，为研究其大功率驱动下的非线性本构模型奠定了基础； 5、界定压电振子的动力学特性指标，对压电振子的机电耦合动力学模型参数进行计算及变参数仿真；依据等效电路模型，对压电振子的电学特性进行了仿真分析；通过有限元数值实验，对压电振子工作模态附近的模态振型及工作频率附近的频段进行了激振效果分析，找出了实现模态简并的激振频率；利用有限元控制方程，通过编程计算，对压电振子的力电耦合场参数进行了详细计算，得出了一些有价值的结论。

Electromagnetics course mainly including basic phenomena and laws of electro- magnetics, electrostatic field in vacuum, in conductor and in electric medium, electric energy, stabilized current, stabilized magnetic field and its basic laws, electric and magnetic fields caused by a moving chager in lower speed, the transform of electric and magnetic fields between different systems of coordinates, inductive laws, eddy field, self inductance, mutual inductance and transient, molecule current and magnetic substance, ferromagnet, boundary conditions, magnetic circuit theorem, energy of magnetic field and density of magnetic energy, displacement current, Maxwell's equation, electromagnetic wave, Poynting vector.

电磁学课程的主要内容包括：静电的基本现象和基本定律，真空中的静电场，导体和电介质中的静电场，电场的能量与电场能量密度，稳恒电流，稳恒电流磁场的基本定律，运动电荷的电磁场，不同参照系之间电磁场的变换，电磁感应定律，涡旋电场，互感，自感，暂态过程，分子电流与磁介质，铁磁体，边界条件，磁路定理，磁场的能量和磁能密度，位移电流， Maxwell 方程组，电磁波和玻印廷矢量等。

In the electric motor soft start question, uses the crystal thyratron intelligence module which controls by the singlechip to change the electric motor the initial firing current, the realization soft start; In the protection question, uses the singlechip to monitor the electric motor the movement, to lacks the breakdown implementation to separate the electrical machinery movement immediately, according to certain algorithm judgment electric motor whether crosses the class, like tallies has flowed the condition is the separation electrical machinery movement.

在电动机软起动问题上，采用由单片机控制的晶闸管智能模块改变电动机的起动电流，实现软起动；在保护问题上，采用单片机监视电动机的运行，对缺相故障实行立即断开电机运行，根据一定算法判断电动机是否过流，如符合过流条件即断开电机运行。

Beijing hung Electric Vehicle Co., Ltd. is a master of domestic electric vehicles, hybrid electric vehicle design and production of one of the manufacturers, the main design and manufacture of environmental protection, safety, energy-efficient new electric vehicles, currently has a tourist vehicles, car clubs, golf carts, flatbed, tractor and so on 5 big series more than 30 varieties.

北京鸿马斯特电动汽车有限公司是国内电动汽车、混合动力汽车设计和生产的厂家之一，主要设计和生产环保、安全、节能的新型电动汽车，目前已形成旅游观光车、会所用车、高尔夫球车、平板车、牵引车等5大系列30多个品种。

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Warming needle is one of effective treatment methods for knee arthralgia aggravated by cold,and it is simple,safety,so it should be developed in clinical acupuncture and moxibustion extensively.

但以本院科针灸门诊在2005年1月—2006年6月期间共收治膝痛患者100余例，经过临床的诊断后，其中施以温针治疗的48例，疗效显著，报道如下。1临床资料本组病例48