脉冲

The mutual coherence and angular correlation function of scattered wave from two dimensional rough surfaces is derived with Integral Equation Model and then calculated for perfectly conducting rough surfaces, then the scattering of incident pulse wave with different shape is calculated and the shape of scattered pulse is presented.

采用积分方程法推导出了二维粗糙面的双频互相关和角相关函数，数值计算了具有不同粗糙度的良导体粗糙面的双频互相关函数，在此基础上分别计算了二维粗糙面对δ脉冲、Gaussian脉冲和矩形脉冲的散射，并给出了散射脉冲的波形。

The intensityand phase of the pulse were quantificationally measured,and the spatial chirp and pulsefront tilt induced by angular dispersion were qualitatively measured.

描述了空间啁啾和脉冲倾斜的传输规律，建立了一套飞秒脉冲测量装置，对飞秒激光脉冲和光谱的强度和相位进行了定量测量，对角色散引起的空间啁啾和脉冲倾斜进行了定性测量。

With the obtained model of the power spectrum, we have theoretically analyzed the contribution of all the amplitude noise, timing jitter and pulse width jitter to the total noise power spectrum. The simulated results show that while the product of pulse width and angular frequency is larger than 1, the pulse width jitter will contribute an amount of noise to the total noise power.

利用得到的模型，理论分析了激光输出光脉冲各个噪声项对总噪声功率谱的贡献情况，并数值模拟了输出脉冲功率谱，结果表明在脉冲宽度角频率积大于1的情况下，脉冲宽度抖动对总噪声功率谱有很大的贡献。

Transmitting and receiving impulse response of two-dimensional array are obtained by the summing impulse response of a single rectangular element with differentia delay time. The approximation arithmetic of array element impulse response is discussed.

讨论了单阵元声场脉冲响应函数的快速近似算法，通过对不同延时量的矩形单阵元声场脉冲响应函数进行叠加，得到了二维换能器阵列的发射和接收脉冲响应函数，再施加以宽带脉冲激励函数，从而得到二维换能器阵列的声场分布。

The foundation of this system provides a good reference to promote the standardization and intelligence of the overhaul and maintenance of vacuum switches. This paper develops a special HF pulse power supply for internal pressure estimation, which achieves the output of HF-HV sinusoidal pulse wave whose frequency and amplitude can be modified respectively, and meets the design requirements according to the results of Simulink simulation and practical experiments. With the help of AT89S52, this paper designs an I~2C serial bus based signal detection system for peak value signal acquisition of HF pulse currents, which communicates with the upper computer by asynchronous serial communication for uploading the data. In the upper computer, a human computer interface is developed by Matlab software, whose functions are to do some computation and graphic display, such as calibrating the relation curve of vacuum degree and peak value of HF pulse currents, vacuum degree computation, and vacuum lifetime evaluation analysis basing on grey forecasting model as well as making relative suggestions.

本文研制了用于真空度检测的高频脉冲电源，通过Simulink仿真和试验检验其满足设计要求，实现了电压幅值和频率独立可调的正弦波高频高压脉冲输出；利用以AT89S52为核心基于I~2C串行总线的信号检测系统实现高频脉冲电流峰值信号的采集，通过异步串行通信实现单片机与计算机之间的数据通信，将检测数据传至上位机；在上位机利用Matlab开发人机交互界面，实现相关数据处理和图形显示，包括真空度——高频脉冲电流峰值关系曲线标定、真空度数值计算、基于灰色预测模型的真空寿命评估分析和提出相应决策建议。

When the chirped pulse with area smaller than propagates in the medium, splitting doesn't occur and the chirped pulse evolves gradually to an approximate normal Gaussian pulse (C=0), and this characteristic doesn't vary when the chirp coefficient; however, variation of the chirp coefficient will change amplitude and group velocity of the pulse.

面积小于的啁啾脉冲，在介质中传播时不发生分裂，且啁啾脉冲逐渐演化为一个近似的无啁啾(C=0)脉冲，这一特点不随啁啾系数的改变而改变；但啁啾系数的变化将改变脉冲的振幅和群速度。

Pulse power supply, with its discrete characteristic, has a wide application in the field of EDM, pulse electroplating, electric weld, high power laser pump, high frequency induction heating, purification of exhaust gas and waster water, electrostatic dust precipitation, ozone production and surface heat treatment.

而脉冲电源由于具有断续供电的特性，在电火花加工、脉冲电镀、电弧焊接、高功率激光泵、高频脉冲感应加热、工业废气处理、脉冲电解污水处理、静电除尘、臭氧制取和表面热处理等领域获得了广泛的应用。

Result Biphasic electrical field pulse extended the APD longer than that with monophasic one.

结果 双相电场脉冲比单相脉冲更多地扩展细胞的动作电位时程；不同强度的双相波电场脉冲，对动作电位时程的扩展能力非常相近，而不同强度的单相波对动作电位的扩展能力差别很大，电击后动作电位时程空间分布不均匀；动作电位的扩展主要取决于脉冲强度的峰值，和脉冲持续时间关系不大。

The results of study showed that there were many interference signals in discharge detection signal for the DC feeder cable, which determined by the special electric wiring of the cable. The results of laboratory simulation and field measurement showed that the main interferences involved discharge pulse generated by other equipments of the traction substation, white noise, rectifying pulse generated by the rectifying equipments, current pulse generated by the braking of the locomotive,stochastic pulse signal, and narrow-band signal generated by electric equipment.

研究结果表明直流馈出电缆的电气接线以及负荷特点决定了其放电监测中存在大量的干扰信号，干扰信号包括白噪声、交流侧放电脉冲、直流侧其它设备的放电脉冲、整流装置产生的整流脉冲、机车启动制动产生的电流脉冲、随机性干扰脉冲以及其它电子设备产生的周期性窄带信号。

Basing on the Monte-Carlo calculations of the detectors'responses to radiation and n/γdiscrimination ability, their radiation response properties are experimentally investigated on pulsedγrays, X rays from Z-pinch processes, n/X mixed radiation fields of the DPF neutron generator, electron beams of BEPC II Testing Beam Facility.

完成了探测器辐射响应、n/γ分辨能力的蒙特卡罗模拟计算，开展了探测器对脉冲γ射线、Z-pinch过程脉冲X射线、DPF装置脉冲中子/X射线混合场、BEPC II试验束装置脉冲电子束及国家串列加速器脉冲质子束的辐射响应实验研究。

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。