脉冲波

Short TR, short TE spin echo or short TI, short TE composite inversion recovery (IR spin echo images are used to demonstrate the high signal that develops at some time after the ictus, as early as 10 hours but typically 2-3 days, and persists for a variable length of time, from a few weeks to a few months.

短TR，短TE回波脉冲(或短TI，短TE 整合反转恢复回波脉冲)影像主要用于显示高信号，这种信号常是病变爆发后产生，最早10小时，但典型是2-3天。并且高信号可持续几周甚至几个月。

The locomotive adopts chopper main circuit of 4 uncombined phases and a control mode featuring accessory pulse generated firstly, main pulse secondly, and central phase shifting of the 4 phases.

该车采用了4相不重的斩波主电路和先发副脉冲、后发主脉冲及4相集中移相的控制方式，并特别试制了适用于斩波的滤波电容器及换相电容器。

The quantity computed is the expected clutter power at the output of any specified range gate by the method of integrating reflected energy between constant Doppler loci in range-gate circles with a model of sum and difference antenna gain pattern for APAR. Base on the analyzing of APAR terrain clutter spectrum, Rayleigh, Correlated Log-Normal and Weibull distribution terrain clutter of APAR general pulse signal was simulated with the method of zero memory nolinearity transform.④The Doppler frequency of target echo is simulated on video frequency in this dissertation.

该软件采用了用C语言建立框架结构，而在程序高重复部分和有运算速度要求的地方，用汇编语言编写具有高并行能力程序的方法，不仅满足了系统高运算速度和实时性的要求，也使得软件系统结构模块化，代码具有良好的维护性和重用性；③对机载相控阵雷达HPRF、MPRF的和、差通道地面杂波功率谱进行了较为全面的研究，通过建立由四个子波束构成的机载相控阵雷达杂波和差波束天线方向图数学模型，选取体现高度线杂波的修正的地面后向散射模型，以载机平飞为例，采用沿距离门——等多普勒线区域积分的方法，得到了杂波功率谱，并利用零记忆非线性变换法实现了机载相控阵雷达常规脉冲情况下瑞利分布、对数正态分布和韦布尔分布地面杂波的模拟；④提出了采用在视频上对目标回波的多普勒频率进行模拟的方法。

The results indicate that there are vortexes, shocks and expansion waves outside the multi-tube PDE. In addition, the results might be referrible to research the characteristics of the flow-field outside multi-tube Pulse Detonation Engine.

计算结果表明，此多管脉冲爆轰发动机黏性外流场中存在旋涡及多道相互作用的激波与膨胀波，该结果对多管脉冲爆轰发动机外流场特性研究具有一定的参考价值。

This approach followed a novel idea: the main-lobe clutter spectrum is regular for the deviation azimuth of clutter is corresponding to its Doppler frequency, while the returns of moving targets violate this regularity, so it\'s reasonable to use the azimuth error in each Doppler channel as a detector of ground moving target.

该方法以一种新的思路，利用单脉冲雷达和波束主杂波谱区固定回波的偏角与多普勒频率相对应的规律性，将动目标回波视为对这种规律性的干扰，从而利用单脉冲测角误差在主杂波谱区进行地面极低速动目标检测。

A method and apparatus for increasing the propelling force of pulse engine features that the fuel nozzle of pulse explosion engine is arranged in combustion chamber to close jet tube exit, and the fuel is reversely sprayed out to generate a shock wave barrier near the jet tube for preventing the airflow from flowing out of the combustion chamber, resulting in raising the pressure in combustion chamber and in turn increasing the propelling force.

本发明公开了一种提高脉冲发动机推力的方法和装置，它是通过将脉冲爆轰发动机的燃料嘴置放在燃烧室中靠近喷管出口附近，并使燃料逆向喷出，在燃烧室内靠近喷管附近形成一道阻止气流流出燃烧室的激波，激波的作用是使燃烧室压力升高，从而的到较大的推力。同时由于本发明的结构特别的简单，所以实现非常容易，并且工作效果十分显著。

When several ultrafast pulses are propagating simultaneously, nonlinear processes such as cross-phase modulation, cross non-degenerate TPA, SRS and four-wave mixing, and so on, will be considered. One of the nonlinear processes will play dominance for various conditions.

当多波长超快脉冲在波导中传输时，脉冲之间将发生交叉相位调制、交叉非简并双光子吸收、受激拉曼散射和四波混频等非线性过程，在不同的条件下，将具有不同的非线性过程起主导作用。

The response of a short single-wire line excited by EMP was theoretically investigated and experimentally validated by means of an EMP simulator.

研究了有界波电磁脉冲模拟器下短线缆效应的理论建模和实验方法。基于传输线模型计算了线缆在有界波电磁脉冲模拟器辐照下的电流响应。

In addition, the analyses of weld surface ripple and microstructure with three current waveforms have indicated that the high frequency wave group modulated by low frequency GTA welding has the advantage of both the low frequency in which the heat input of the weld pool is easily controlled and high frequency GTA welding in which the arc is energy—concentrated and stiff.

另外，通过对高频脉冲焊、低频脉冲焊、低频调制高频方波群焊不锈钢焊缝表面形貌分析表明，低频调制高频方波群焊综合了低、高频GTA焊的特点。

This paper introduces the studies of the ultra-short Thomson scattering X-ray source at the accelerator laboratory of Tsinghua University in recent years. Properties such as the photon yield,the pulse length and time jitter of the produced photon pulse were predicted theoretically from the parameters of the electron bunch and the laser pulse,and the scattering angle. Preliminary experiments were successfully carried out with a 16 MeV backward-traveling-wave accelerator and the ns-Q switched laser provided by China Academy of Engineering Physics. This paper also introduces the 1.6-cell electron gun that was fabricated on site and the experiment with high RF power including the measurement of the electron bunche parameters. Based on these,we have designed an X-ray source,which is now under construction.

介绍了清华大学加速器实验室近年来关于汤姆逊散射超短X射线源的研究工作；研究了在任意散射角度下电子束参数和激光束参数对散射光子参数的影响，给出了散射光子的参数如光子产额、脉冲长度、时间抖动等与电子束参数、激光束参数和散射角度的关系；利用实验室已有的16 MeV反波行波加速器与中国工程物理研究院激光聚变研究中心提供的ns调Q激光搭建了汤姆逊散射初步实验平台并开展了实验研究；加工了1.6-cell光阴极微波电子枪，搭建了高功率实验平台，对产生的电子束参数进行了初步测量；对汤姆逊散射超短X射线源进行了设计并开展了相关的平台建设工作，对产生的X射线脉冲参数进行了模拟。

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。