频率调制

Seeded amplification of colored conical emission and two-dimensional multicolored transverse arrays as well as simultaneously up-converted parametric amplification have been demonstrated using spectral synthesis to obtain sub-fs pulses.

基于分子调制过程，文章作者提出并发展了一系列亚飞秒脉冲产生和操控的技术；围绕频谱合成方案，利用级联二阶非线性效应，实现了多色圆锥辐射注入放大和二维多色阵列及其参量上转换放大；同时，还开展了基于飞秒振荡器及外腔增强技术的高重复频率高次谐波产生与输出耦合的相关研究。

Oscillation modulation circuit which can provide the signal carrier with stable frequency is the key point in the subject.

本课题重点在于设计能给发射机电路提供稳定频率的振荡调制电路。

It proposes an improved Dynamic Frequency Selection scheme, in which traffic allocation unit and scheduling information delivery are selected by subchannel domain, modulation and coding domain, subcarrier domain.

提出了一种优化的动态频率选择方案，该方案是对资源分配单元和调度信息传递在子信道域、调制编码域和子载波域的三维选择。

In radio communications, a frequency in a superheterodyne receiver or transmitter system that enables easier filtering, distribution, modulation, and demodulation of a signal

在无线电通信技术中，超外差接收机或发送机系统中使用的一种频率，能够方便地对信号进行滤波、分配、调制和解调。

The control mode has developed from early U\f control mode to vec to r control technology and pulse width modulation.

控制方式也从早期的电压；频率控制方式发展到向量控制技术和冲宽度调制技术。

Therefore this way is feasible, and the system is simplified.⑤A procedure of analyzing in target echo theory and simulation for APAR is described in the dissertation.

因而在视频上模拟目标回波的多普勒频率的方法是可行的，并且简化了系统；⑤对机载相控阵雷达目标回波的理论分析和模拟实现进行了深入研究，在目标回波模拟系统方案中采用了用一路目标信号通过和、差波束天线方向图增益进行调制并用移相器控制和、差通道相位的方法，产生目标三个通道的信号。

A phase-shifted controlling PWM DC/DC full bridge converter with softswitching is proposed and used to realize a constant current power of20A(5～48V).This full bridge converter utilizes the transformer leakageinductance(or the resonant inductance in series with transformersprimary)and the autoecious capacitance of MOSFET to achieveZVS(Zero-Voltage-Switching),as a result it can decrease the switchingwaste,increase the switching frequency,and diminish the power bulk.

本文使用一种通过移相控制进行脉宽调制的软开关全桥变换器来实现20A(5～48V)恒流源，这种全桥变换器利用变压器的漏感、原边串联谐振电感和功率管的寄生电容来实现开关管的零电压开通，降低了开关损耗，提高了开关频率，减小了电源体积。

Comparing to single rf source CCP, ion flux and electron flux will be influenced by both of the sources in the dually rf driven CCP. Therefore, particles in plasma behave more complicated.

与单频电容耦合放电相比，在双频电容耦合放电等离子体中的离子和电子受到的是两个不同频率的射频偏压的调制，从而使等离子体表现出更为复杂的运动行为。

Almost no neurons in the deprived layers responded to the drifting sinusoidal gratings to the nondominant eyes, while half of the neurons in the non-deprived layers did.

但是，与非剥夺层神经元相比，几乎没有剥夺层的神经元能对非优势眼的正弦移动光栅刺激起反应，并受其空间频率的调制。

Four laser beams used for ~ 40 K and ~ 87 Rb cooling and repump lights are obtained by using acoustic optic modulators to offset the frequencies from the three external cavity diode lasers.

三台ECDL通过声光调制器产生四束光，分别作为40K和87Rb原子的冷却光和再抽运光，四束不同频率成分的激光分别注入锁定四台从激光器，然后Rb冷却光、K冷却光和K再抽运光再同时注入半导体激光放大器进行放大。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。