查询词典 high frequency

The frequency step-by-steps in the above frequency range is 250Hz; The phase noise is low; The output profile degree of distortion is small, and outputs the frequency after ring circuit locking the temperature stability and the time stability and the datum frequency is same.

在上述频率范围内频率步进是250Hz；相位噪声低；输出的波形的失真度小，并且在环路锁定后输出频率的温度稳定度和时间稳定度与基准频率相同。

The light frequency shift ,collision frequency shift and microwave power frequency shift on long term stability of influencing rubidium atom frequency standard are discussed in this paper.

对影响铷原子频标长期稳定度的光频移、碰撞频移和微波功率频移进行了分析。

ABSTRACT:The half-power bandwidth method is the commonly used method at home and abroad, the authors discover that factors, such as the sampling frequency, the frequency resolution, the ratio of the sampling frequency to the signal frequency, the analyzed width and the damping ratio, make the estimated damping ratio fluctuate vastly. Mostly the result is incredible except for some conditions, the error is sometime amazing, which is not acceptable.

半功率带宽法是国内外常用的测试阻尼的方法，笔者发现半功率带宽法由于受到信号处理中的①采样频率SF②频率分辨率△f③采样频率与信号频率之比K ④采样分析的长度T和⑤阻尼比D的大小等因素的影响使得测得的阻尼比值波动很大，除少数状态是可信的外，多数状态是不稳定的，有时误差惊人，得到的测试数据不能使用，易导致错误的结论。

Nowadays the researches of frequency distribution of data are almost limited to normal distribution, while other distributions are seldom studied. Many frequency distributions of data are not normal. This kinds of frequency distribution of data widely exist. Unimodal frequency distribution of data often occurs.

现在绝大多数关于频数资料分布的研究都是基于正态分布的，而对其他类型的分布研究得比较少，实际上频数分布在许多情况下并非呈现正态分布，分布的形态丰富多彩，很多资料都是呈现单峰分布，本研究就是利用数学上常见的八种连续型变量的分布类型去拟合单峰频数资料。

Then the creative research work on ultra-low frequency and large amplitude elcectromagnetic vibrator based on moving magnet is done, improving exciting signal at ultra-low frequency, and, the theoretic analysis and experiment model are studied. Thus, the reference for establishing ultra-low frequency standard vibrator in future is provided. In chapter 5, two control strategies for ultra-low frequency standard vibrator test table waveform are studied.

首先采用机械振动隔振理论，研究设计了机械低通滤波器来滤除噪声信号，并运用等效的小振级信号进行了实验研究，得出了有益的结论；然后为提高超低频时激振信号，作者创造性地提出了动铁型大位移的电动振动台结构，进行了理论分析和实验模型研究，为将来建立大位移的超低频标准振动台提供了参考。

The study on the electrical property shows that its dielectric property decreases with the slowly increase of frequency in dry state; in hygrometric state (52.9%), the dielectric property grows obviously and declines swiftly with the increase of frequency; and it tends to be stable when the frequency is over 10^4Hz. The specific resistance decreases linearly with the increase of the frequency. The results indicate that the electric properties of the hot press moulded wheat gluten are subject to the compaction rate of the material structure.

对小麦麸质模压板的电性能研究表明，干态下其介电性能随电场频率增加而下降，但变化小；湿态下其介电性能明显提高，且随频率增加迅速下降，超过10^4Hz后区域变化趋于稳定；热压小麦麸质材料的电阻率随频率的增加呈直线下降；小麦麸质热压材料的电性能主要决定于材料结构的密实程度。

The target king security analysis system is becomes by the wealth culture dissemination center research and development, in integrates 2380 outstanding targets, target operational, you do not need the profound stock theory, may the proper operation, be truly the fool type speculates in the stock market the software; In the software speculates in the stock market in the toolbar, has each kind of stock calculator, the real-time foreign exchange treasure, the video on demand, the online P2 television, the stock good world information, the daily publication magazine, the electronic painting pen, to grasp the chart tool, the organization memoir, the fund radar, the big list inquiry, ultra to win functions and so on rank, and in this help video frequency has the auspicious thin software operation video frequency help and ten extended functions, the user may act according to own demand the software which likes oneself to integrate in this software; But in software's time sharing chart, we integrated this important connection website for you, the user, so long as enters some stock in the time sharing chart, has underneath the left ultra wins the picture, ultra to win the rank, to win the data, ultra to win the data, the L2 data, the DDE target, the BBD target, the panoram information, the unification stock market, the stock news and so on this connection website, the user, so long as clicks may examine this stock the related information; But "the service" in the option card also integrated several hundred well-known finance and economics websites and the video frequency website in the software, may for the user inquiry finance and economics information, ultra win finance and economics related contents and so on data, fund quotation, finance and economics video frequency, news information.

指标王证券分析系统是由财富文化传播中心研发而成，内集成2380个优秀指标，指标操作性强，你不需要高深的股票理论，就可以正确操作，真正是傻瓜式炒股软件；在软件的炒股工具栏内，有各类股票计算器、实时外汇宝、网络电视、在线P2电视、股行天下资讯、每日报刊杂志、电子画图笔、抓图工具、机构研究报告、资金雷达、大单查询、超赢排行等功能，且此帮助视频内有祥细的软件操作视频帮助和十个扩展功能，用户可以根据自己的需求把自己喜欢的软件集成到本软件中；而在软件的分时图中，我们又为你集成了该股重要的关联网站，用户只要进入某股票的分时图中，在左下方就有超赢图片、超赢排行、全赢数据、超赢数据、L2数据、DDE指标、BBD指标、全景资讯、统一股市、个股新闻等该股关联网站，用户只要点击就可以查看该股的相关信息；而在软件的&服务&选项卡中还集成了几百个知名的财经网站和视频网站，可供用户查询财经资讯、超赢数据、基金行情、财经视频、新闻资讯等财经相关内容。

This paper bases on frequency-hopped and frequency synthesis theories, and through demonstrating three schemes of frequency synthesis, the paper selects one of these schemes that uses DDS spiriting up PLL and improves on the method according to the practical target and synchronously, the paper analysis the capability of the output signal and the conversion time of the frequency.

本文在对跳频理论及频率合成理论分析的基础上，在讨论三种频率合成方案后，设计完成了一种适于本课题的DDS激励PLL的混合方案，并对频率合成器主要性能中的输出信号的噪声特性和频率转换性能做了研究分析。

Based on the requisition of wireless system debugging, this paper develops a novel radio-frequency beaconing. Design method and system constitution of a novel beaconing based on PLL IC PE3336 are given, and the accomplish method of the system's hardware and software arc expounded. The test results show that the beaconing adopted in this method has a reliable and stable frequency conversion features. The more applications in the wireless system find that the users can set necessary frequency conveniently. Especial1, the friendly man-machine interface makes the operation is more flexible. It is as excellent performance-price-ratio beaconing, and as a signal source, it can be used in the research and the debug procession of variable radio-frequency components.

根据无线电数据链系统及部件的调试需要，研制开发了一种新型的以锁相环为核心、由单片机控制的射频信标机；文中给出了基于锁相环芯片PE3336的新型信标机的设计方法与系统组成，阐述了系统硬件及软件的具体实现为法；测试结果表明，利用该方法设计的信标机具有稳定、可靠的变频特性，且各项指标均达到了要求；进一步在某无线电系统中的应用发现，用户可方便地设置所需频点；特别是友好的人机界面，使用户操作更为灵活方便，是一种性能价格比优良的信标机；并可作为信源用于不同的射频部件研制与调试过程中。

Taking the development platform of HVDC power transmission for example, the calculation result of impedance-frequency characteristic of traditional line commutated converter and that of FCC are compared. Simulation results show that the impact of impedance-frequency characteristic of converter on the resonance frequency of AC system is not negligible, and FCC can enhance the strength of AC system in a certain extent, improve system stability and effectively reduce AC equivalent impedance under resonance frequency, thus the harmonic instability of HVDC power transmission system can be avoided.

以直流输电开发平台为例，对传统电网换相换流器(line commutated converter，LCC)与FCC的阻抗频率特性计算结果进行对比，仿真结果表明换流器的阻抗频率特性对交流系统的谐振频率有着不可忽略的作用，FCC在一定程度上提高了交流系统强度，改善了系统稳定性，有效降低了系统谐振频率下的交流等值阻抗，从而更好避免直流输电系统谐波不稳定现象的发生。

Finally it offers the analysis of the fault-tolerance system as well as its test verification.

这样，运行于空间环境中的系统的设计目标就是在保证系统实时性

However, it is still difficult to find out the real reason of the increase of the keratinized gingiva during the orthodontic extrusion whether it is due to the proliferation of the gingival tissue or to its elastic nature, that is because the proliferation of the fibroblasts as well as the connective tissue changes in volume and the intra-fibers spaces were all immeasurable in most of the studies.

然而，仍然难以找到真正的原因增加的角化牙龈在正畸挤压它是否是由于扩散的牙龈组织或其弹性性质，这是因为增殖的成纤维细胞以及作为结缔组织的变化量和内部纤维空格都是不可估量的，大多数的研究。