脉冲宽度

The laser generates picosecond pulses with a rectangular-shaped spectrum, the FWHM width of which can be greater than 19 nm.

该类型脉冲的光谱近似为矩形，半高全宽光谱宽度可达19 nm以上，脉宽为皮秒量级。

By measuring the change of primary voltage of the transformer in several periods, PI controller adjusts the width of pulse so that flux imbalance of the transformer is limited in a reasonable scope.

通过检测变压器原边电压在几个周期内的变化量，利用PI调节器得出的控制量来适时的调整触发脉冲的宽度，把变压器直流偏磁限制在较小的范围之内。

Theory analysis and the measured data are shown that excitation pulse in pile integrity testing is silimar to half-period of the sine curve, and different exciting methods produce signals with different period of time, so its frequency composition is also different.

理论计算及实测资料表明，反射波法基桩动测激振信号近似为半周期正弦波，不同激振方式产生的桩顶速度脉冲信号宽度不同，相应频率成分也就不同。

The operation voltage was applied as a rectangular pulse of 50 kV amplitude and 3.75 μs width, and the antiferroelectric adjuster was made up by lead zirconate stannate titannate ceramics.

工作电压是幅值为50kV、宽度为3.75μs的方型脉冲电压，反铁电调节器由锆锡钛酸铅反铁电陶瓷组成。

The selected subject gives a general design of the grating auto testing instrument, by using the characteristics of orthogonal A and B signals output by optical encoder and symmetrical black and white linear transmission grating bar, and analyzing the means of the high electrical level of signals change to number of counter pluses.

本文通过分析了编码器输出两路信号的正交性(相位相差90°)与直线透射式光栅黑白栅条的分布均匀性的特性，应用把高电平宽度转换为计数脉冲的个数的测试方法，给出了光栅自动测试仪的总体设计方案。

Both UV and NIR lasers were collinearly focused into 2.0 atm Ar gas cell,when satisfying the conditions of space-time overlap,the full width at half maximum spectrum of UV could grow from 2.6 nm without interaction situation to 6.4 nm,a factor-of-2.5 improvement,which can provide a valid way for attaining sub-20fs ultrafast pulses in the range of UV.

将紫外激光与近红外激光共线聚焦注入2.0 atm氩气样品池中，在满足时空重合条件时，半高全宽的紫外频谱宽度可从无相互作用时的2.6 nm展宽至6.4 nm，增加2.5倍，为进一步获取该波段小于20fs超快脉冲提供一个重要的途径。

Especially, with the improvement on microelectronic integrating technique and the development of hegh-speed electronic devices in the recent decade, the rise time and width of working pulses have been reduced to the ps range in high-speed digital circuits. In such fast pulses there are microwave and even milliwave components, so analysis of the time-domain response of multiconductor tuansmission lines used as interconnects in high-speed integrated circuits must be performed to ensure the normal working state, Much research work has been done and many analysis methods have been developed.

近十年来随着微电子集成工艺技术的提高和高速电子器件的发展，高速数字电路的工作速度提高迅速，脉冲信号的上升时间和宽度已缩短至ps量级，对应的频谱已进入微波甚至毫米波波段，这种情形下对信号连接线的时域响应加以分析就成为保证高速电路正常工作的必要环节。

Secondly,two-photon entangled pair is produced in noncollinear direction.Wediscuss the influence of fourth-order interference with three different length crystalsand with different frequency distribution of interference filters.

其次，利用飞秒脉冲II型参量下转换在非共线方向产生偏振纠缠的双光子对，我们利用三块不同长度晶体分析晶体长度以及探测谱线宽度对纠缠四阶干涉的影响，实验选用长度分别为0.1mm、0.5mm和1.0mm的BBO晶体。

A DC high brigytness laser driven by photoemissive electron gun is being developed at Peking University,in order to produce 50～100ps electron bunches of high quality.

采用激光驱动光阴级和100kV直流加速间隙可产生宽度为50～100ps的高亮度脉冲电子束。

The experiment result shows that this control method can improve the dynamic performance of the motor control system, which accelarates motor responds and restrains overshoots. For the step external disturbance, the system speed only shows a pulse fluctuation with a width of 0.1 s, and the amplitude is one half of that of PID controller.

实验结果表明，该控制方法显著地改善了电机控制系统的动态性能，使电机响应迅速而且没有超调；对于阶跃型外界扰动，系统的速度仅出现了宽度为0.1 s的脉冲型波动，且幅度比PID控制至少减小50%。

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。