拍频

Using the autocorrelation function, the principal of homodyne method is explored. The relationship between delay time induced by delay fiber and characteristics of additive frequency-domain fluctuation affixed on homodyne beat noise photoelectric-current spectrum are intensively analyzed.

一、利用自相关函数研究了零拍法测量激光线宽的原理，重点考察了零拍光电流谱线上所附加的频域周期性波动，确定了该波动的频域周期与光纤延时线所产生的时延成反比。

Considering the technical requirements,the stability andthe steady performance,the quantitative requirement for sampling frequency is present indiscrete control system.Considering that there is a step delay in discrete control in grid on inverter with a Lfilter,the quantitative relationship between critical FCCR and sampling frequency isanalyzed,and the steady performance is analyzed.Considering the technical requirements,the stability and the steady performance,the quantitative requirement for samplingfrequency is present in discrete control system with a step delay.

在L型并电加热管网中，考虑到离散化控制存在滞后一拍的问题时，本文分析并获得了离散PI控制系统稳定范围时闭环根临界频率fnmax和采样频率fs之间的定量关系；针对存在滞后一拍可能引起系统稳态特性下降的问题，分析了PI控制滞后一拍对频域特性造成的影响，综合考虑并网指标、稳定性要求和离散化对稳态特性影响三个主要因素，推导了存在滞后一拍的离散化PI控制对最低采样频率的量化要求。

Finally, we have employed phase-diffusion model to study the effects of laser field correlation on the Raman-enhanced nondegenerate four-wave mixing.

从物理角度讨论了多普勒增宽相位共轭极化拍频和DeBeer提出的超快调制光谱学之间的差别。

We have studied the polarization beats spectroscopy with phase-conjugation geometry in a cascade three-level system.

文摘：研究了级联三能级系统中的相位共轭极化拍频光谱术。

It dose not need a gas laser tube with a piezoelectric ceramic made by special technology.

由于采用了锁相技术，它的自差拍频率的变化率小于1Hz，其光频的稳定度为2.2×10~(-11)(取样时间τ=10s)。

With ordinary photocells, one can pick up the frequency between two different lasers.

用普通光电池，人们就能够探测到两个不同的激光之间的拍频。

With ordinary photocells , one can pick up the frequency between two different lasers

用普通光电池，人们就能够深测到两个不同的激光之间的拍频。

We believe that the improvement of the frequency response is due to a two-mode beat that includes the main mode of the slave laser and the master laser mode, which coincides with the side band of the slave laser.

激光器频率响应的改善可以用两个模式的拍频来解释，一个模式是从激光器的主模，另一个是主激光器的模式，该模式与从激光器的边带重合。

First, the relationship among dissonances, beats, and critical bandwidths is analyzed.

首先分析不协和音、拍音与临界频宽的关系。

Frequency stabilization laser based on transverse Zeeman effect provides several characters such as high stabilization frequency.

基于横向塞曼效应的稳频激光器，频率稳定度高，抗干扰能力强，输出功率大，差拍信号频率低、易于接收和处理，可直接输出相干性和偏振度都很好的线偏振光，便于测量偏振、双折射等物理量。

Objective To investigate the effects of interleukin-1 β converting enzyme gene on the biologic characteristics of ovarian cancer cells.

目的 探讨白细胞介素-1 β转换酶的表达，对卵巢癌细胞生物学特性的影响。

Campylobacter: This illness is the most commonly identified cause of diarrheal illness in the world.

弯曲：这种病是最常见的原因查明腹泻病，在世界上。