反向脉冲谐波成像；
目的探讨不同肝局灶性病变在超声造影反向脉冲谐波显像时的动态灌注过程及其特征。
Objective To characterize the dynamic contrast enhancement in focal hepatic lesions with pulse inversion harmonic (PIH) ultrasonographic imaging.
结果显示，超短脉冲谐波辐射过程中电子获得动能的量子路径偏离主要量子路径，而且该偏离效应受载波包络相位的影响。
The results show that the quantum path through which the electron gains kinetic energy deviates the dominant quantum path. In addition, the deviation is effected of the carrier-envelope phase.
采用含有丰富谐波分量的窄脉冲电流作为励磁信号对非晶丝直接励磁，使传感器具有灵敏度高、响应快的优点。
The magnetic sensor has characteristics of high sensitivity and quick response due to the amorphous wires excited directly by sharp pulse train current containing amount of harmonic signals.
然而，由于开关电源工作在高频状态，其产生的瞬态脉冲包含有能够发射电磁干扰(emi)的的高频谐波。
However, SMPS operate at high switching frequencies, and the associated transient pulses are full of high frequency harmonics that may cause electromagnetic interference (EMI).
后来，采用12脉冲变流器，但是由于谐波失真的缘故，后来这种技术就没有再持续。
Later used 12pulse converters, but this technique could not be used further on because of harmonic distortion.
谐波相位参考在频域上为梳状波而在时域上为很窄的脉冲序列。
Generally, the harmonic phase reference circuit is a comb generator in frequency domain and a pulse generator in time domain.
为了获得振幅均衡的有理数谐波锁模脉冲，必须在原有的实验装置中添加一个掺铒光纤放大器(EDFA)以提高注入调制光信号功率。
For obtaining a pulse series with a small amplitude ripple, an Erbium-doped Fiber Amplifier (EDFA) must be added into the primary experiment setup to enhance injection-modulation signal power.
计算由于车辆的运行而使储油罐受到脉冲激励及谐波激励作用下，储油罐的响应。
The oil tanker's response are calculated when it get the impulsive excitation and harmonic excitation.
数值计算了强激光啁啾脉冲中原子的谐波辐射。
Highorder optical harmonic emission from a single atom exposed in the intense chirped laser pulses has been calculated.
具有谐波选择和啁啾补偿作用的极紫外啁啾多层膜反射镜是产生亚飞秒脉冲的有效元件。
The chirped multilayer mirror in the extreme ultraviolet region can be used to select some high harmonics and compensate the chirp.
通过在浊音段提取多脉冲激励信号加入语音的状态方程，有效地重建语音的高频谐波。
By extracting the multipulse excitations during voiced speech, and adding the excitations into the process equation the harmonic of high-frequency area can be reconstructed.
由于传统谐振直流环节逆变器只能采用离散脉冲调制方式，输出波形中含有丰富的低次谐波，严重影响输出性能。
The output waves of traditional resonant DC-Link inverter have too much low frequency harmonic waves which affect the output performance, because it can only use DPM control.
介绍了采用IGBT逆变电路的高压脉冲电源的设计和电路构成。该电源可以减少电源对进线电源的谐波干扰，提高电源的品质，减少输出电压的交流分量。
This paper presented an IGBT inverter for high voltage pulse source. The experimental results demonstrate a good harmonic elimination for power input and quality output.
改进的PRI变换法克服了直方图统计法的子谐波问题，对脉冲重复间隔具有很高的估计精度，且具有一定的抗抖动能力。
The improved PRI transform estimates PRI with high precision, overcomes the sub-harmonic problem produced in the histogram methods, and has a better performance on anti-jitter.
为了获得稳定的谐波锁模脉冲，分析了有理数谐波锁模的理论和非线性放大环镜的传输特性。
To achieve a steady harmonic mode-locked pulse (HMLP), the theory of rational harmonic mode-locking and the transmission characteristics of a nonlinear amplifying loop mirror were analyzed.
有理数谐波锁模技术是产生高速超短脉冲的重要技术之一，其光时分复用通信技术等领域中有重要的应用价值。
The rational harmonic mode-locking has become a research subject of intense interest due to its application on the generation of ultra- high repetition frequency optical pulse train.
而对于SPWM逆变，采用数字电路实现SPWM触发脉冲的生成，在消除谐波、提高开关频率、简化电路结构，提高集成度和可靠性等方面，取得了很好的效果。
The digital circuits are introduced in the SPWM inversion, which have brought the elimination of harmonics, high switching frequency, simplified circuits and high reliability.
结果表明脉冲电流的波形关系到谐波的频域及能量在其频域上的分布。
The results show that the wave pattern of pulse current determines on the frequency range of harmonic wave and the distribution of energy of pulse current among the frequency range.
分析表明要想使高次谐波获得相位匹配，需要超短脉宽的驱动脉冲以及电离能大的气体工作介质。
The calculations show that a ultrashort pulse laser and the medium with higher ionization potential is necessary for generating higher order phase matched harmonic.
用一维粒子模拟程序研究了超短脉冲强激光与超临界密度等离子体平板作用产生的高次谐波。
Using the one-dimensional particle-in-cell simulation code, we have studied the generation and redshift of harmonics from overcritical plasma layer irradiated by ultrashort intense laser pulses.
我们用光谱分辨的二次谐波方法测定了连续波同步泵浦染料激光脉冲形状的非对称性。
We have determined the pulse shape asymmetry in a synchronously pumped dye laser using the method of spectrum-resolved SHG correlation.
这种中压变频器输出电压为多电平pwm脉冲波形，目前对其谐波还没有完善的理论分析。
Output voltage of this type ASD is multilevel PWM waveform, and by now there is not perfect theoretical analysis for its harmonics.
给出用光谱分辨的二次谐波自相关法测量输出脉冲的结果，证实在锁模脉冲中已发生频率调制。
The results of the spectrum-resolved SHG correlation measurements of the mode-locked pulses also are presented, which confirmed the presence of frequency chirping in the pulses.
在相应于谐波锁模、有理数谐波锁模条件下得到了稳定的脉冲输出。
Steady pulses were obtained on harmonic and rational harmonic mode-locked status.
通过对半控双三相12脉冲整流器的电流波形分析和傅立叶级数展开，得出系统的主要谐波成分。
Through analysis of the current waveform of the semi-control double three-phase 12-pulse rectifier and the expansion of Fourier series, the main harmonic components of the system were obtained.
结果发现：（1）对一定强度和频率的激光脉冲，紧束缚的势场抑制高次谐波的产生；
Two facts are found: (1) For the given laser pulse, the tighter the potential bound the electron, the difficulter scattering harmonics extends to high order;
由于超短脉冲具有较宽的光谱范围及较高功率密度，倍频转换效率和谐波脉冲波形将受到许多因素的影响。
Conversion efficiency and pulse wave-forms will be affected by many factors due to the wide spectrum range and high intensity density of ultra-short pulses.
设计电流模脉冲宽度调制直流转换器时，人们广泛采用斜坡补偿电路来消除谐波振荡。
In the design of current-mode PWM DC-DC converters, the slope compensation method is widely used to prevent sub-harmonic oscillation.
将智能化激光超短脉冲宽度测量仪与非共线二次谐波相关仪相结合，可获得0.1微微秒或更优的时间分辨率。
An intelligent instrument used for measuring the width of ultrashort laser pulse is presented. Combining with a noricollinear SHG correlator, time resolution of 0.1 psec or better can be obtained.
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