标准频率

电动车组车体弯曲振动标准频率的保证

Ensuring the Standard Frequency of Carbody Bending Vibration of EMUs

标准频率指数统计法在汉语词频统计中的应用

Application of standard frequency index method in calculation of Chinese word frequency

目前水平是：对原子时UTC（NIM）进行校准，能在两个月以上的时间内连续提供频率不确定度优于3×10~（-13）的标准频率信号。

At present , when calibrated against atomic time UTC ( NIM ), this frequency standard can provide a standard frequency signal for successive two monthes above , uncertainty of which is better than 3 × 10 ~ ( - 13 ) .

改善氢脉泽标准频率稳定度和工作可靠性所采用的技术

Techniques used to Improve the Frequency Stability and Reliability of Hydrogen Maser

在没有标准频率信号源的情况下测量振荡器频率稳定度的一种方法

A method of frequency stability measurement without frequency standard

电视信号中的标准频率在同步广播中的应用

The Application of the Standard Frequency in Television Signals to the Synchro - broadcast

GB/T16700-1996集中网络控制装置的标准频率

Standard frequencies for centralized network control installations

这样使测频误差在理论上只含有标准频率误差，可以使测量误差降低。

By doing so , there will only be standard frequency error in theory and decrease the measuring error greatly .

利用单片机内部高稳定度的标准频率源和定时/计数器，可方便地测量信号的频率和周期。

With application of the standard frequency source and the timer counter , the signal frequency and period are easily measured .

电视信号中的标准频率信号是受原子钟控制的高稳定度、高准确度的信号。

The standard frequency in television signals is a signal with high stability and accuracy , controlled by the atomic clock .

所以，一般采用锁相技术来锁定石英晶体振荡器的频率，而把锁定的频率作为标准频率使用。

So the phase-locked technique is used to phase-lock a standard crystal oscilla - tor to a hydrogen maser at a cardinal frequency .

对于这种信号，在接收端用锁相环路恢复标准频率时，不能使用普通的鉴相器，必须用采样保持鉴相器。

For this signal , a general phase detector can not be used , sample-and-hold phase detector must be used in the phase-locked loop recovering the standard frequency signal .

选择线性热敏电阻组成的脉宽电路，将脉宽作为控制计数的时间，由晶振产生某一标准频率的脉冲信号，通过分频以及计算译码驱动送显示。

The pulse width circuit , which is consisted of the linear heat sensitive resistance , are selected with the pulse width as the time controlling the counting number .

线型离子阱把199Hg+离子作为工作物质，利用离子囚禁技术，制成有很高准确度和稳定度的标准频率源。

The ions can be trapped in the linear ion trap to make the standard frequency source with higher accuracy and stability by the trapping technique using () ~ ( 199 ) Hg ~ + as active medium .

该红外吸收式的甲烷浓度报警器由单片机系统、光源调制模块、信号调理模块、数码显示模块、声光报警模块、遥控接收模块、标准频率输出模块等电路组成。

Infrared absorption methane concentration alarming device is comprised of microcontroller systems , light modulation module , signal conditioning module , digital display module , sound and light alarm module , remote control receiving module , standard output module interface circuit .

此方法是将两个被比对的标称值相同的标准频率信号之间的相位关系，通过线性鉴相器转换成与它成线性关系的电压信号，并通过相应的设备进行显示纪录。

In this method , the phase difference between two compared signals that have same nominal frequency can be converted into voltage signal by phase detector . The voltage signal varies linearly with the phase difference and can be displayed or recorded by some instruments .

采用标准信号频率高的FPGA芯片，在满足测频的精度的要求下，可以提高测试系统的速度。

If FPGA die with higher frequency of standard clock is used , it can accelerate the measurement speed with the same frequency measurement precision .

电视信号中标准时间频率的应用

Application on the Standard Time and Frequency Carried by CCTV Signals

设计洪水标准与频率计算方法的统计试验研究

Statistical test analysis on design flood standard and frequency calculation method

卫星发播标准时间频率的多普勒频移补偿

The Doppler Frequency-shift Compensation for Standard Time and Frequency Dissemination via Geostationary Satellite

非标准设备频率特性的自动化测试

Automation Test for Frequency Characteristic of Nonstandard Facilities

GB/T7402-1987利用电视信号传送标准时间频率

Time and frequency dissemination via television signals

是否要使用此分辨率的标准屏幕频率及角度设置？

Do you want to use the standard screen fequency and angle settings for this resolution ?

随着科技的进步，人们对高精度标准时间频率的需求越来越高。

As development of science and technology , the demand for high-precision time and frequency standard is increasing .

随着科技的飞速发展，精确时间频率的应用已经深入到测控、导航、通信、电力、交通等部门，人们对高精度标准时间频率的需求也越来越高。

With the rapidly development of science and technology , the precise time and frequency have been applied to monitoring and control , navigation , communications , electricity , transport fields , etc * The demands in high precision time and frequency standards are becoming higher and higher .

从两相流流型的空间几何意义出发，利用差压计作传感器，提出用标准空间特征频率斯特罗哈尔数Sr作流型识别的定量依据，斯特罗哈尔数Sr识别流型具有明确的物理意义。

Considering the spatial geometric significance of two-phase flow patterns and using the differential pressure gauge as a sensor , the Strouhal number Sr is taken as the basis for distinguishing flow patterns . Using Strouhal number Sr to identify flow pattern has clear physical meaning .

实验采用对偶法。标准激励为频率8Hz、加速度1.0m/s2的正弦振动，实验激励也是正弦振动，频率为4～80Hz，共14种。

They were exposed to standard vibration stimulus ( a sinusoidal vibration of 1.0 m / s 2 at 8 Hz ) and 14 kinds of sinusoidal experimental vibration stimuli at frequencies from 4 Hz to 80 Hz .

电力系统中标准时间、频率的采集和传输

Acquisition and Transmission of Standard Time , Frequency in Power System

四端对标准电容器频率特性的校验理论及测定方法

Calibration Theory and Measurement Method of the Frequency Characteristics of the Four-Pair-Terminal Standard Capacitor

在通信技术发展的同时也带来了多种通信体制并存、各种标准层出不穷和频率资源缺乏的现象。

With the development of mobile communication , there are many problems including kinds of communication systems kinds of criterions frequency resource starvation .