反电动势

For the power in case of a power failure, back electromotive force of a spindle motor can be utilized.

对于在电源故障情况下的电力，可利用主轴电机的反电动势。

The principle of the back electromotive force detection method is analyzed. The detection circuit is designed, and the problems of its application and solutions are studied in detail. This will improve the practical use.

为此本文在分析了无刷直流电动机反电动势检测方法的原理后设计了反电动势检测电路，并详细分析了在实际应用中存在问题，给出了解决的方法，为其实际应用奠定了基础。

Back electromotive force was measured by continuous pulse-computer and the influencing factors for back electromotive force and current efficiency were studied in detail.

研究了在SrCl2-SrF2-BaF2的电解质体系中熔盐电解法制备高浓度Al-Sr合金，采用连续脉冲-计算机法测定电解过程的反电动势并且对反电动势和电流效率的影响因素进行了详细的研究。

In addition, the primary causation for the problem that phase current during reverse braking process out of control is a short loop by the back electromotive force.

同时，针对反接制动时电流无法控制的问题，该文指出反电动势短接回路的存在是造成再生电流无法控制的主要原因。

The thesis first probably explains BrushLess Direct Current Motor, and discusses the related control methods, explains the background and Meaning of back electromotive force which is used in the thesis.

本文首先对无刷直流电机进行了概述，并对其相关控制方法进行了讨论，说明本文所采用反电动势法的背景和意义；接着论述了无刷直流电机基本组成环节、基本工作原理、运行特性和传递函数，然后是详述本文研究的重点：基于反电动势法的MATLAB调速系统的仿真以及基于反电动势法的DSP控制系统的实现。

In addition, since the back electromotive force occurring in an inductance element is cleared to zero during a half wavelength of period of the cosine wave, speed electromotive force can be measured by immediate shifting from a setting period to a measuring period.

另外，由于在余弦波的周期的半波长期间，使在电感元件中产生的反电动势VL清零，通过立即从设置周期转移到测量周期，能测量速率电动势。

In order to eliminate direct current drift and saturation problems of pure integrator for back electromotive force,an improved programmable low-pass filter rotor flux estimator was proposed to replace the pure integrator.

为了有效抑制反电动势积分环节所存在的直流偏移和积分饱和问题，采用一个截止频率可根据输出频率进行自调整的低通滤波器来代替传统电压模型磁链观测器中的反电动势积分环节。

The results indicate that back electromotive force increases with increasing current density and decreases by 0.5 V after adding 2% Li2CO3, the feeding period is 15 min measured by the method of electric potential control. Finally, the Al-Li alloy with the lithium content of 7.93% can be obtained by electrolyzing for 3 h at the current density of 0.62 A/cm^2 and at 680 ℃, and the current efficiency can reach 74.1%.

结果表明，反电动势随电流密度增加而增大，加入2%的Li2CO3可使反电动势降低0.5V；通过控制电位法测得加料周期为15 min：在680℃、电流密度为0.62A/平方公分的条件下持续电解3h，最终制得了理含量高达7.93%的铝锉合金，电流效率可达74.1%。

The thesis first probably explains BrushLess Direct Current Motor, and discusses the related control methods, explains the background and Meaning of back electromotive force which is used in the thesis.Then the thesis expounds the basic component parts,the basic running principle,the running characteristic and transfer function of the BLDCM.And then the thesis detailedly dissertates its research pivot: the simulation of BLDCM system in MATLAB based on the method of Back-EMF and the control system of Digital Signal Processor based on the method of Back-EMF.

本文首先对无刷直流电机进行了概述，并对其相关控制方法进行了讨论，说明本文所采用反电动势法的背景和意义；接着论述了无刷直流电机基本组成环节、基本工作原理、运行特性和传递函数，然后是详述本文研究的重点：基于反电动势法的MATLAB调速系统的仿真以及基于反电动势法的DSP控制系统的实现。

With the raw material and the particle size of reducing agent narrowed, the percent reduction of strontia increases.(6) With the barbecuing pressure increasing, the percent reduction of strontia increases, after the certain value, the percent reduction of strontia decreases instead.(7) With reduction temperature increasing, the percent reduction of strontia increases.(8) The percent reduction of strontia is increasing with prolonging reduction time. In this experimental condition, it will become steady after 2.5h.

通过实验研究确定以SrCl_2-SrF_2-SrCO_3的纯锶盐体系作为电解质，实验中还采用了我们最新研制的熔盐电解监控仪对电解过程进行测量和系统的研究，得出以下结论：(1)增加电流强度，反电动势亦随之增加，而升高温度反电动势则有所降低；(2)随着电流密度的升高和电解时间的延长，电流效率逐渐增加，达到峰值后稳步下降；(3)延长电解时间，合金中锶的含量逐渐增加，最高可达18.1％；(4)开始电解后，反电动势逐渐增加，但向熔体中加入SrCO_3后，反电动势明显降低，因此认为在正常电解时是SrCO_3在分解。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。