脉动理论

Direct torque control is another high performance control technique of AC motor, it discard the decouple idea of vector control, but adapt flux oriented control and transient space vector theory, directly control stator flux and torque, it has the advantage of rapid torque response and less relying on stator parameters, but has the disadvantage of bigger torque ripple.

直接转矩控制技术是继矢量控制技术之后的又一种交流电机高性能控制技术，它摈弃了矢量控制中解耦的控制思想，采用定子磁链定向和瞬时空间矢量理论，直接对电机定子磁链和转矩进行控制，具有转矩响应快、对电机参数依赖小的优点，但它的不足之处就是存在转矩脉动。

In the paper, the effective range of the quasi-steady theory for pulsating flows is discussed.

本文确定了脉动流动中准稳态理论的适用范围。

A general matrix perturbation method for complex modes using singular value decomposition;2. The modal character,the error of the substituting by real modes and the best way to extract real modes from complex modes are discussed.

建立运动方程，用第一振型将主体结构展开，针对非经典阻尼和非对称结构以及脉动风谱为非有理分式风谱的情况，运用复模态理论将所得方程进行解耦，获得了以第一振型表示的结构随机风振响应的解析解。

Dynamic characteristics of the two models are surveyed. By employing the POD-based spectral representation method, the turbulent wind-velocity field around the bridge is simulated and verified.

根据POD型的谱表示法模拟了桥梁的脉动风速场并进行了相关性拟合检验，然后基于准定常理论计算了作用在模型上的抖振力时程。

Based on rate equations, by use of a new method, a semiconductor optical amplifier theoretical model is constructed taking carrier density pulsation, spectral hole burning, stimulated emission, free carrier absorption, two-photon absorption and ultrafast nonlinear refraction effects into account.

基于速率方程采用新的推导方法得到了可以用来讨论飞秒量级光脉冲传输特性的半导体光放大器理论模型，该模型同时考虑载流子浓度脉动、光谱烧孔、受激辐射、自由载流子吸收、双光子吸收和超快非线性折射效应。

By theory analysis and using zero voltage vector,a PMSM DTC control system model has been established in Matlab,and the simulation study shows that zero voltage vector can effectively diminish the torque ripple and improve the system performance.

在理论分析的基础上采用零矢量的控制方案，建立了基于Matlab/Simulink的PMSM直接转矩控制伺服系统模型。仿真结果验证了加入零电压矢量可以有效地抑制转矩脉动，提高系统性能。

In this paper,the equation of angular speed and centrifugal acceleration on a part in the fuze is derived according to the movement of circumrotatory ammunition at exterior trajectory.

根据旋转弹丸在外弹道上的运动，推导出了引信零件在弹道上的运动角速度和离心加速度表达式，通过计算和模拟仿真得到了脉动的离心加速度曲线，在引信动态模拟装置上进行模拟测试，验证了理论分析的正确性，提出了通过直接计弹丸转数实现引信定距功能的方法。

M/s. The following dimensionless relationships were obtained: Sh=2+0.073Re〓Sc〓〓〓 The desulphurization process by powder injection and blowing in RH refining of molten steel and its mechanism have been considered and analyzed. Based on the tworesistance mass transfer theory and the mass balance of sulphur in the system, a kinetic model for the process has been developed. The related parameters of the model have been reasonably determined. Modeling and calculations for the process by injecting and blowing the lime based powder flux under the assumed operating modes in a RH degasser of 300t capacity have been carried out using the model.

考虑颗粒与液流的相对速度，RH—PTB条件下熔池传质特性可由下式表征： Sh=2+0.073Re〓Sc〓考虑紊流中脉动速度引起的能量耗散，RH—PTB条件下熔池传质过程服从如下关系：〓将粉剂颗粒与钢液间的传质当作刚性的气泡与钢液间的传质处理，对RH—PTB过程有：〓考察和分析了RH喷粉脱硫过程及机理，基于双重阻力传质理论和体系内硫的质量衡算，建立了RH喷粉脱硫过程的动力学模型，确定了模型各有关参数，包括各传质系数和脱硫处理过程中钢液内参与脱硫反应的粉剂量等。

My personal, completely pseudoscientific, theory is that the link units create a quantum entanglement between the two brains where they effectively become one pulsating system without the need for any traditional radio comm of any kind.

我个人的，完全伪科学，理论是该单位建立联系的两个大脑之间的量子纠缠，他们实际上成为无需任何形式的传统广播通信设备需要一个脉动系统。

At last, natural frequencies of practical pre-stressed composite space truss are tested with pulsatory method on construction site and its damping ratio is calculated, which gives another important data for engineering design. In addition, through the model experiment of pre-stressed rectangular square pyramid composite space truss, the correctness of characteristics of internal force and the feasibility of tension recovery method are proved.

最后，在工程施工现场用脉动法测试自振频率，并借助于振动衰减曲线和半功率点法计算出预应力组合网架——钢与混凝土的混合结构体系——的阻尼比，此又为工程设计提供了一理论依据；另外，通过正放四角锥预应力组合网架的模型试验，验证了结构内力分布特点的正确性以及张力松弛法的可行性。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。