脉冲激发

To explain the time-resolved fluorescence depletion, we develop a dynamics theory of spectroscopy for a vibrational relaxation process, and a decay rate constant of the vibrational state on the excited electronic state is taken to be 〓〓 in which γ is vibrational relaxation rate constant of the transition 0→1 and k〓 is the Boltzmann constant.

电子激发态上的波函数可写作〓相比于以前密度矩阵理论的布居表象，本文所提出的波函数表象理论为在更本质的层次上揭示振动弛豫过程的物理图象，特别是研究超短脉冲激发下含有振动弛豫的动力学光谱创造了条件。

Laser acoustic energy conversion efficiency induced by pulse laser in water.

脉冲激光在水中激发声脉冲的光声能量转换效率。

The intensity of pulse noisy pixels significantly differs from adjacent pixels of image. The de-noising will be accomplished by modifying the intensity of the noisy pixel according to the firing patterns of adjacent neurons of PCNN. At last, this dissertation suggests a new kind of filter for de-noising pulse noise based on the PCNN and median filter. It is very simple, and the simulation experiment of the image processing shows that the de-noising effect is much better than neighborhood averaging method and median filter.

一般脉冲噪声点与其所在图像像素灰度值之间相关性很差，而PCNN脉冲耦合神经网络能使相似神经元同步激发；这就决定亮点脉冲噪声像素对应神经元会在其区域所在相邻神经元中首先激发，为此结合中值滤波，我们提出了结合PCNN脉冲耦合神经网络和中值滤波的混合滤波新算法，理论分析和实验证明，该方案在滤除噪声的同时，比常规中值滤波更有效地保持了图像的高频细节信息。

The optimal condition determined through the experiments are to prefabricate hole of 0.8mm diameter and 1.0mm depth,and collect the plasma radiation excited with second pulse,the laser spectra of higher property can be obtained.

实验确定的优化条件是，预制0.8mm直径和1.0mm深度孔穴，采集第二个脉冲激发的等离子体辐射，可以获得较高质量的激光光谱。

The techniques of optical beam induced current have found wide-spread applications in characterizing many semiconductor and optoelectronic devices. A two-photon confocal microscope is adapted for investigating the dynamics of light emitting devices through the contrast mechanisms of two-photon DC and radio frequency optical beam induced current.

摘要 光致电流的技术至今已经广泛的被应用在检测半导体特性以及光学元件上，共焦显微镜搭配双光子激发技术相当适合用来检测LED元件，与单光子激发相较之下，利用脉冲雷射双光子激发术可以使用光子能量小於能隙的长波长光源来完成激发，并且具有高度的空间解析度。

Secondly, we provide a two-level model to depict the one-, two-and three-photon fluorescent process and with it to calculate the one-, two-and three-photon fluorescence intensity dependence of the incident excitation intensity and time. We study the fluorescence intensity when excitation light's time distribution are square pulse、Gaussian pulse and sech pulse. We find that the influence of excitation light's time distribution on the two- and three- photon fluorescence peak intensity is larger than the one-photon fluorescence peak intensity. Two-level model can account for the behavior of saturation fluorescence.

然后用二能级模型解释了单、双、三光子激发原理，在理论上推导出了单、双、三光子吸收诱导荧光强度与脉冲强度以及脉冲作用时间的关系，并进一步研究了入射光时间分布分别为矩形、高斯型、双曲正割型时激发溶解在氯仿溶液中的C22H22N4O样品所产生的荧光峰值光强，结果表明激发光的时间分布对双、三光子荧光峰值强度的影响比对单光子的影响要大。

Third, it has a discussion on the development of modern and traditional artificial neural network technology and their application in image processing. It summaries that the model of the Pulse-coupled neural network based on Elkhorn's model of the cat visual cortex was constructed according to the mammalian vision systems. The nonlinear modulation property, which is a generic and pervasive biological pulse-coupling mechanism, is used in the construction of PCNN. So, PCNN finds many applications in image processing, including segmentation, edge extraction et al. As all known, the performance of the image segmentation depends not only directly on the adjustment of PCNN parameters and the statistical properties of image but also on the cyclic iteration times N of PCNN. If the parameters have been properly set, it turns out to be essential to select a suitable criterion to determine N.

回顾了神经网络技术的现状，指出传统人工神经网络只利用了生物神经元有限的属性进行模型构建，而90年代产生的脉冲耦合神经网络充分利用了哺乳动物视神经网络特有属性，其神经元模型除了考虑生物神经元特有的线性相加、兴奋与抑制属性外，还考虑到生物神经元特有的非线性相乘调制耦合特性；考虑了哺乳动物视神经系统视野受到适当刺激时，相邻连接神经元同步激发产生35Hz～70Hz振荡脉冲串特性等，所以PCNN网络模型更靠近真实生物视觉特性，特别是哺乳动物视神经网络，特别适合计算机图像处理应用，尤其在生物细胞图像分割、图像平滑、降噪及图像中目标的分类、计数等方面的研究。

Objective: To measure the variation and significance of respiratory impedance and pulmonary ventilation function in patients with bronchial asthma by impulse oscillometry before or after the bronchial provocation test, investigate the relationship between the IOS method and bronchial provocation test, and evaluate the clinical significance in bronchial asthma by IOS method.

目的：应用脉冲振荡法测定支气管哮喘患者在支气管激发试验前后的呼吸阻抗及肺通气功能参数的变化规律和临床意义，探讨IOS测定方法能否作为支气管激发试验的判断方法以及IOS测定参数在哮喘诊断中的价值。

For a relatively longer intense short-pulse laser, especially when local phase matching in the laser pulse between the ponderomotive force and the wake plasma oscillation occurs, there is strong electron acceleration in the laser-excited wake field and weak acceleration inside the laser pulse.

对于脉冲相对较长的短脉冲激光，尤其是在激光脉冲内等离子体尾波振荡和有质动力发生局域的相位匹配时，在激光激发的尾波场电子有很强的能量，这时在激光脉冲内电子的有质动力加速效率很低。

X-ray ,which is excited from the X ray tube, has one wavelength scope, that is energy scope. According to the elements to be analyzed, X ray is choused by filter, and reach the sample. Atoms in the sample will absorb the X ray energy and the decay to emit the special x ray. The X ray will be collected by the collimator into the detector active area, and transferred into electron signal, the signal also will be processed in to energy spectrum and related concentration data by pulse processor with software.

从X光管通过激发Excitation发射出来一定波长范围也就是说一定能量范围的X射线，结合所需要分析的目标元素，使用滤光轮选择对应的能量范围的X射线，照射到样品上，样品中含有的元素原子电子受到激发会发射出其特征的X射线，同样通过Collimator准直器收集一定孔径的X射线进入到检测器Detector，检测器将感应到的X射线转换为电信号，电信号经过脉冲处理器Pulse Processor结合软件进一步将电信号转换成为能谱图以及相关浓度信息。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。