脉冲波

The variation tendency of pulse pressure waveform along acoustic axis and in the focal plane has been numerically studied also.

同时还数值研究了脉冲压力波沿声轴和焦平面上的变化趋势，在幅度下降-6 dB的焦斑内没有观察到波形的明显变化。

The homogeneous nucleation rate, saturation rate, and droplet growth equation at state 250K、100Kpa for pentone affected by single expansion wave has been obtained in the joined international cooperation research. Results exposed that temperature decrease in the homogenous nucleation and condensation is the preponderant factor in unsteady adiabatic expansion process.

参与同质核化率实验的国际合作研究，获得250K、100KPa状态附近戊醇在单脉冲膨胀波作用下的同质核化率、饱和度及同质核化微滴在低压状态中长大状态方程；研究表明非定常绝热膨胀过程中，降温因素在同质核化和凝结过程中占主导作用。

The data are discrete electrical pulses. The wave is an analog representing the data.

数据是离散的电脉冲，波是表示数据的一个模拟量。

The analyzer introduced in this paper has nine polarographic analytical techniques including the differential pulss polarography and the square wave voltammetry, etc.

本文介绍的微电脑多功能极谱仪具有微分脉冲极谱法和方波伏安法等九种极谱分析技术。

We firstly bring forward and realize technologies of arbitrarily shaping laser pulse in the time domain by chirped pulse stacking, programmablely shaping spatial intensity by crystal liquid diaphragm, focused spot smoothing using angular spectrum dispersion by special gratings and detecting and compensating the small patch wave front aberration. Precise, programmable, efficient and \'all parameters\' condition of high power laser system has been obtained.

首次提出并实现了啁啾脉冲堆积型的时间波形任意整形；液晶光阀可编程光强空间整形；特殊光栅光谱角色散焦斑束平滑和小尺度波前畸变的探测和补偿，从而对高功率激光系统的激光束实现了高精度、可编程、有效的"全息"控制。

The simulation results reveal not only that the approximate calculation have high accuracy, but also that the models of clutter and target have profound influence on the detection performance under the condition of single pulse.

仿真结果既表明了近似计算具有较高的精确度，同时也表明了在单脉冲条件下，杂波和目标模型对检测性能有较大的影响。

The object of the filtering is to enhance the direct pulse from the shot and to attenuate the ghost.

滤波的目的，是改善来自炮点的直达脉冲并压制伴随波。

In particular, it is found that the output ripple voltage of boost and buck DC-DC converters are related to the duty ratio of input pulse.

本文提出了开关DC-DC变换器的线性空间建模法，并将其成功地用于升压型和降压型DC-DC变换器的分析，首次导出了上述两类变换器的输出纹波表达式，特别是输出纹波与控制脉冲占空比之间的关系。

In the process of building and using the mass concrete structures, because of the effect of out-side condition and themselves, some faults will form in the structure, these faults will effect the bearing capability and endurance Using nondestructive testing method to test the concrete"s quality and diagnose its healthy, which has the significant sense in assessing the safety stability and research of the administering diseasesThis dissertation mostly researched the testing methods in the mass concrete structure, discussed the principles, methods, features, sphere of application of the ultrasonic testing in the mass concrete structure with faults, used dynamic FEM to simulate the testing process, discussed when the concrete structure with cracks is under the effect of the pulse, how the elastic waves propagate and what are their changing feature, Researched the principles of the first-arriving waves" phase when the cracks" depths are not same, obtained the relation between the inversion point and the cracks" depth, which has the direction sense in the application of projects,The second part of this dissertation is CT , which used the ultrasonic wave running through the tested-substance to get arriving-time of the ultrasonic wave, then inverse the image This dissertation drawed one CT program which can well present the different little cells ultrasonic wave velocity profiles of the substance, thereby to diagnose the quality of the part of the tested-substance, CT has the better using foreground..

在混凝土结构的施工及使用过程中，由于受其自身及外界各种因素的影响，常常会产生一些缺陷，对结构物的承载能力和耐久性造成严重影响，采用无损检测技术进行质量检测和健康诊断，这对混凝土结构开展安全、稳定性评估以及病害隐患治理研究具有重要意义。本论文主要针对大体积混凝土结构缺陷的检测方法展开研究工作，重点讨论了超声波法检测混凝土结构裂缝的基本原理和方法及其特点、适用范围，运用动力有限元数值模拟其检测过程，探讨了有裂缝缺陷的混凝土结构在脉冲荷载作用下弹性波的传播及其变化特征，研究了不同裂缝深度下首波相位变化规律，得出了反转临界点与裂缝深度之间的关系，这对实际工程应用具有指导意义。声波CT是一种新的无损检测技术，它是利用声波穿透被检测体获取声波接收时间，来进行计算机反演成像的技术。本文利用直射线法编制了层析成像程序，能较好地呈现被检测物体各微小单元的声波速度分布图像，从而对检测体的质量状况作出诊断评估，具有较好的应用发展前景。

It is shown also that the propagation of the soliton with an order of amplitude of picosecond width is hardly to produce stimulated Raman amplification, but the soliton with narrower width (generally, smaller than few picoseconds) is better synchronous with Raman wave, and the stimulated Raman amplification can be produced easily.

在相位交调、光纤损耗和脉冲走离并存的情况下，论文详细讨论了基态孤子传输中的喇曼波产生，得到了相位交调导致喇曼波辅加周期放大的结论，并首次给出了辅加放大因子和放大周期的表示式，同时首次给出了由于孤子光纤损耗导致的最大放大距离的表示式。

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。