脉冲波

The law, which equivalent inductance and effective permeability of magnetic core vary with field current under the excitation of high frequency and large power, is discovered, and this will offer an important reference for the reasonable selection and effective use of material in the design of high frequency large power magnetic components.

在对高频功率磁元件测试中的影响因素进行深入研究的基础上，推导出方波、占空比可调矩形波、单极脉冲波及周期变化的任意波激励下磁元件测试与正弦波激励情况的等效，为解决磁元件在高频任意波激励下的在线检测提供了依据。

Finally, based on the characteristics of transient responses and the Morlet wavelet, a family of wavelet functions is introduced and used in the simulation of modal analysis.

文中分析了在众多小波基函数中Morlet小波更适合对动态结构系统进行模态分析的原因，结合Morlet小波的性质和结构系统对脉冲响应信号的特性，构造了一小波族，实现了利用Morlet小波变换对多自由度系统进行模态解耦和对时变系统进行模态参数辨识的方法。

Development of OA kneepad : The kneepad density-wave output can be controlled by 2Hz different frequencies to 300 Hz stimulation pulse component, the pulse width of 100 to 150 μ s between the positive and negative output symmetry to the stimulation pulse. The rechargeable mobile phone batteries ( 3.7V) were served as power supply and SCM as timer with automatic shutdown after 30 minutes.

OA护膝的研制：护膝输出的疏密波可控制由2～300Hz不同频率刺激脉冲组成，脉冲宽度在100～150μs 之间，输出正负向对称的刺激脉冲，采用可充电的手机电池(3.7V)供电，单片机定时，30min 自动关机。

We present the linear extrapolation which predicts the required optimum normalized fiber lengths for the optimum pulse compression experiments. Two of the most important nonlinear processes occurring in optical fiber are sefl phase modulation and stimulated Raman scattering .

我们从理论上首次分析了波破裂现象对光纤-光栅对激光脉冲压缩的影响，对以往的经验公式予以修正，给出了最佳脉冲压缩实验所要求的光纤长度的经验公式，以方便激光脉冲压缩实验中对光纤长度的选择要求。

With the shadowgraph method, three ultrasonic pulses in water, which corresponds to the conversion modesof the fast compressional wave the transverse wave and the slow compressional wave in the sample of fluid-saturatedporous medium respectively, were observed and recorded by CCD camera.

用阴影法和CCD照相，观测到声脉冲透过流体饱和孔隙介质（按英文"Fluidsaturatedporousmedum"的第一个字母缩写为FSPM）样品后在水中传播的三个声脉冲，这三个声脉冲分别对应于FSPM样品中的三种体波的转换模式。

The whole PWM circuit contains two subcircuit, the front-end is PWM module that make up of the counter that based on nine MOSFET True-Single-Phase-Clock D flip-flop; the back-end is demodulated module, which is consist of a three order Chebyshev low-pass filter used trans-conductor capacitor. All the subcircuits are simulated. At last, an approving simulated result of the whole circuit is given too.

在调制部分，利用九管单相时钟D触发器构成计数器，并由此组成了脉冲宽度调制电路，同时给出了在典型温度下的仿真结果；在解调部分，介绍了低通滤波器从无源到有源的设计方法，设计了三阶切比雪夫低通跨导电容滤波器，同样给出了相应的仿真结果；最后，作为将脉冲宽度调制电路和滤波器作为整体电路，以脉冲调频波为输入进行了仿真，取得了令人满意的结果。

This problem is also important and valuable in Nonlinear Optics. It will be very helpful to understand how the aberrations affect the course of three- wave mixing, such as the change of conversion efficiency, the distribution of intensity and phase.Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental waves aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.

首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解；通过建立国防科学技术人学研究生院学位论文三维数值模型，编写相应仿真程序，首次得到了位相畸变光束倍频过程的大量计算结果，深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素；得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同，但谐波的远场发散角明显地比相应基波的小的结论；得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下，位相畸变传递到二次谐波的估算式；举例分析了KDP三倍频方案中，基波位相畸变对二次谐波和三次谐波的影响；实验工作中，用哈特曼一夏克传感器分别对IO64nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量，给出了相应结果。

Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental wave's aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.

首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解；通过建立三维数值模型，编写相应仿真程序，首次得到了位相畸变光束倍频过程的大量计算结果，深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素；得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同，但谐波的远场发散角明显地比相应基波的小的结论；得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下，位相畸变传递到二次谐波的估算式；举例分析了KDP三倍频方案中，基波位相畸变对二次谐波和三次谐波的影响；实验工作中，用哈特曼-夏克传感器分别对1064nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量，给出了相应结果。

3D effect is analyzed and the average velocity of wave propagating in the pile, which mainly influences inverse interpretation, is discussed. Finally, the theory results are verified by model experiment. It is shown that 3D results have the same phase with ID results. The pile radius, the duration of impulse, the ratio of hammer radius to pile radius and shear velocity of the soil around the pile have influences on 3D effect. The best position of receiver is 0.55R from the pile center. The average velocity of wave propagating in the pile reduces due to transversal inertia effect and 3D effect.

结果表明：三维曲线与一维结果在相位特征上一致；波场图直观地反映了波在桩中的传播规律；三维效应与桩径、激振脉冲宽度、相对激振半径及桩周土剪切波速有关；传感器放在0.55R处可以得到干扰较小的信号；三维效应和横向惯性效应的存在会使桩中的波速减小，土的性质对波速影响不大；反演精度与缺陷的性质、激振条件有关。

It measures cyclical signal such as frequency ,cycle ,voltage average value or voltage tip-to-tip value of sinusoidal wave, triangular wave, ladder wave, saw-tooth wave, pulse signal and oblique wave which frequency ranges from 64Hz to 1MHz.

本设计为一个多功能数字式测量仪，测量频率范围为64Hz 1Mz的周期性确定信号（如正弦波、三角波、阶梯波、锯齿波、脉冲信号、斜波等）的频率、周期、电压平均值、电压峰峰值。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。