脉冲

Through creating a differential equation whose oscillation is equivalent to the impulsive equation, or considering the relation between impulsive points and delay, we get some sufficient conditions for the oscillation of the equation.

第二章讨论了二阶自共轭脉冲微分方程，通过建立与之振动性等价的微分方程，或考虑脉冲点与时滞间的关系，我们得出方程振动的一些充分条件。

The results of experiment show after inputting impulse current to alloy Al-4wt%Cu, its grain structure can be refined from 1.5 mm to 0.2 mm at impulse voltage 2 kV, capacitance charged frequency 0.5 Hz and circuit oscillatory frequency 50 Hz.

结果表明：脉冲电压2kV、电容的冲击频率为0.5Hz、电路的振荡频率为50Hz时，脉冲电流对Al-4wt%Cu合金作用后，晶粒尺寸由1.5mm减小到0.2mm。

On the basis of the results of survey and study about researches of pulse well test at home and abroad, the method of total pressure history match and numeric solution is selected as an advanced research, the goal is to investigate a method of pulse well test in theory and analysis under the conditions of no knowledging about the changing tendency of formation pressure and having outer boundary.

根据对国内外关于脉冲试井研究情况的调研结果，本文选择全压力史拟合方法和数值求解方法作为一个探索性研究课题，将有限元法应用于压力的数值求解过程，目的是探索一种在地层压力变化趋势不清楚和有外边界的条件下的脉冲试井理论和分析方法，从而为油田提供结果更准确的、信息更丰富的开发调整依据资料。

AL alarm output: when the driver is alarm statue , the port output low voltage..

速度信号输出：如电机的磁极是"P"，则脉冲频率是 3 * P /转（例如，电机是 8 极的，输出信号是 24 脉冲/转）。

The pulse overflow DDS,in which the overflow signal of the phase accumulator is used for the pulse output,can be easily implemented by using FPGA.

脉冲溢出型DDS利用相位累加器的溢出信号作为输出信号，很容易用FPGA器件实现，但它输出的脉冲信号存在相位抖动的缺点。

The pulse overflow DDS, in which the overflow signal of the phase accumulator is used for the pulse output, can be easily implemented by using FPGA. But its pulse output has the drawback of the phase jitter.

脉冲溢出型DDS利用相位累加器的溢出信号作为输出信号，很容易用FPGA器件实现，但它输出的脉冲信号存在相位抖动的缺点。

A class of systems of impulsive delay parabolic partial differential equations with nonlinear diffusion coefficient is considered.

考虑一类具非线性扩散系数的脉冲时滞抛物型偏微分方程组，利用Green公式、垂直相加法和脉冲时滞微分不等式，获得了该类方程组在Robin边值条件下所有解振动的充分判据。

The noise frequency modulation signal was particularly analyzed. The Fokker-Planck equation of noise frequency modulation was presented and the Motion-Group Fourier Transform was used by converting the partial differential equation into the variable coefficient homogenous linear differential equations. Then the solutions were given by using the peano-baker series. So the probability density function of noise frequency modulation in the filter was given. On the basis of the probability density function the stochastic resonance of noise frequency modulation signal is analyzed.

首先建立了噪声调频干扰信号通过脉冲压缩雷达中频滤波器后所满足的福克尔－普朗克方程，然后利用群移傅立叶变换（Motion-Group Fourier Transform，MGFT）将此偏微分方程化成了变系数齐次线性微分方程组，并利用Peano-Baker级数法给出了该方程组的解，最后得到了噪声调频干扰信号通过脉冲压缩雷达中频滤波器后的概率密度函数，在此基础上研究了噪声调频干扰信号造成的随机共振现象。

The spread paths of common mode and differential mode noises in an SMPS under electrical fast transient/burst are studied and discussed. Hereby for single transient pulse, the vector fitting method is adopted combining rational function approximation according to the tested waveform to construct the a mathematical modeling of frequency, then a pole-residue representation is obtained by partial fraction expansion, and the last step are to draw a state space description and equivalent circuit.

在分析开关电源进行电快速瞬变脉冲群骚扰试验时共模和差模噪声的传播途径的基础上，对于单个脉冲，根据试验数据采用矢量匹配法结合有理函数逼近构造得到频域下的数学模型，通过部分分式展开得到零极点表达式，并最终得到相应的状态空间方程以及等效电路。

In this paper, the status and the development home and abroad of the PEC technology are illustrated.

本文首先阐述了脉冲涡流检测技术的特点以及国内外研究现状和发展趋势，论述了脉冲涡流作用原理及其理论基础。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。