脉冲

Due to the short pulse duration of the pulses,UWB signals have significantly more resolvable multipath as compared to narrow signals.

由于具有较短的脉冲宽度，相比于传统的窄脉冲通信，它在接收端具有更多的可接收的多径分量。

The diagnosis of the winding current and the change rate of magntic flux on the magnetic core provides necessary value for determining the hysteresis cycle,saturated magnetic flux intensity and retentiveness of magntic core. Principle of this diagnosis and method of dynamic parameters on magnetic core are discussed.

讨论了基于高电压放电和脉冲压缩方法测量磁芯动态参数的原理，给出了测试装置的电路原理和电路元件参数的选择方法，测量了大型磁开关磁芯快脉冲条件下的电参数，计算了相关的磁参数，给出了实验结果。

Puncture into Attain long sheath of CS through left infraclavicular vein, guided by CS pipe, take sheath into CS, make reverse contrast of heart vein with Attain saccule contrast pipe, put the left ventricle electric pole into the vein through sheath, then bring it into right ventricle apex and right cardiac ear through the electric pole of right ventricle and atrium, connect it with 3-cavity pulse generator, which is buried under left chest skin.

方法］经左锁骨下静脉穿刺送入Attain冠状静脉窦长鞘，在CS导管的导引下，将鞘送人CS，用Attain球囊造影导管进行心脏静脉逆行造影，将左心室电极经长鞘放入选择的静脉，送人右心室及右心房电极至右室心尖和右心耳。与三腔脉冲发生器连接，脉冲发生器埋藏于左上胸皮下。

If a positive voltage is applied to the gold sample, the surface static moment and the applied voltage are parallel, thus the direction of atom diffusion is to the spot directly below the STM tip.

实验表明，当施加正脉冲时，产生的是周围存在沟槽的突起结构，当施加负脉冲时，产生的是周围存在突起的孔洞结构。

Comparison of two kinds of pulse width of ultrashort hyperbol ic secant pulses［J］.

超短双曲正割脉冲的两种脉冲宽度比较［J］。

Moreover, the simulative result shows : under adopting DCF and Sech function , the lower (σ/σ0) min can be achieved at shortest distance ; and under HNLF and Sech function, the lowest (σ/σ0) min can be achieved.

数值仿真的结果表明：在色散补偿光纤和双曲正割型脉冲的条件下，能在较短的距离上获得理想的压缩比；在高非线性光纤和双曲正割型脉冲的条件下，能获得更低的压缩比。

Under the assumption of a sech〓 input pulse, TOD is significant only for pulse widths less than 10 femtoseconds resulting in pulse broadening as well as distinct amplitude oscillations on the leading edge. TOD is positively correlated with its length. The calculations presented here allow for the determination of the maximum thickness of crystal that may be used in the autocorrelation system.

结果表明当脉宽接近或小于10fs时，脉冲才有明显的展宽效应，脉冲的展宽倍数与晶体的长度成递增关系，计算同时给出能基本消除三阶色散的展宽效应的倍频晶体的最大厚度，为进一步实验研究提供了依据。

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。

A diagonal pull tipping-bucket self-recording flow meter based on volumetric method is introduced herein; which consists of tipping-bucket flow sensor, mechanical pulse generator and counter; of which the innovation is that the engine counter used commonly in the weaving industry is successfully applied in the flow measuring through the design of a new mechanical pulse generator .

介绍了一种基于翻斗法量水的自记流量测定仪，该测定仪构成主要包括翻斗式流量传感器、机械脉冲发生器和计数器3部分，其创新点在于，通过自行设计的新型机械脉冲发生装置，将在纺织行业普遍应用的机械式累计数器成功的应用于流量的测定中，该测定仪最大的特点是无需任何动力，抗干扰能力强，特别适合野外工作

In the impulse barrier penetration problem, we use the set of rules of constructing the semiclassical green function to obtain the transmission coefficient which is identical to the results evaluated via standard methods.

在脉冲型势垒的透射问题中，我们利用前面提到的求解体系格林函数的规则，得到了脉冲性势垒的透射系数，数值分析表明与用标准的量子力学方法得到的结果相一致。

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。