查询词典 frequency analysis

It was found that the pemeability of the dust core was almost a constant in the frequency range from 1KHz to 100KHz,and the quality factor Q of dust core increased with increasing frequency.It was also found that Q became higher at the frequency over 50KHz in comparison with that of permalloy in higher frequency.

结果表明，在测量的频率范围内(1KHz-100KHz)，该粉芯的磁导率几乎不随频率变化而变化；粉芯的品质因数Q随频率的增加而增加，在较高频率时有着比坡莫合金粉芯还要高的值，具有应用价值。

Based on the principle of PEC, surface cracks mainly affect the high frequency components and subsurface crack mainly affect the low frequency components, so the PEC signals can be analyzed in frequency domain, which can eliminate the influence of noises during measurement. A method of frequency spectrum separating point is proposed for flaw classification, which enhances the accuracy in classification of defects. The agreement between theory and experiment shows that the present method is valid and applicable.

通过对脉冲涡流的理论分析发现，表面裂纹主要影响脉冲频谱中的高频成分，而表面下裂纹主要影响脉冲频谱中的低频成分，因此可以将时域中易受噪声影响的脉冲涡流信号变换到频域分析，提出了"频谱分离点"的方法来对裂纹进行分类识别，提高了缺陷分类识别的正确率，理论分析和实验结果相一致，证明了该方法的正确性和有效性。

In frequency calculation, the paper takes the positive sequence component as the foundation data, uses the Fourier frequency measurement principle to measure the frequency, thus enhances the frequency measurement stability and precision.

在频率计算上，论文采用以正序分量为基础数据，利用富氏测频原理测算频率，从而提高了测频的稳定度和精度。

Seven experiments were conducted in the present study to test and verify two inferences:(1) In character decision performance, high frequency character have not character stroke and component number effect, but low frequency character is an essential condition to stroke and component number effect;(2) In prime condition, when SOA is very short (SOA=56ms), component character can prime the recognition of low frequency compound characters, but failure to prime the high frequency compound characters.

在此基础上，本文通过7个行为实验验证了这一假设的两个重要推论：(1)在字决定任务中，高频汉字不存在部件数和笔画数效应，而低频字不必然存在笔画数和部件数效应；(2)在启动条件下，当SOA较短（=56毫秒）时，成分字仅对低频合体字有启动效应，而对高频合体字没有启动效应。

And the average WDI for every month was calculated from 60 decades WDI and the drought frequency for every month was obtained with a drought criterion. Results showed that: in spring, North-western China, Northern China and Southern China have a higher drought frequency; in May to August, the region that has a higher drought frequency focus on North-western China and Northern China; from September to December, North-western China, Northern China, center China and Sichuan basin has a higher drought frequency (6) The relationship between average WDI for all the 720 decades in 20 years and average precipitation was analysed and was used to regionalize drought in China.

5分析我国近20年干旱发生的时空分布特征：利用1982-2001年NOAAAVHRR8km数据集，计算了20年来我国各旬干旱空间分布，并根据一定的干旱发生判断标准，统计我国不同地区在各月相发生干旱的频率和各月份平均WDI，初步分析我国干旱发生的时空格局，结果表明：在春季，西北地区、华北平原和华南大部分地区的干旱发生频率都比较高；在5-8月份，高频率干旱发生地区就主要集中在西北和华北平原地区；9-12月份干旱发生高频率地区在主要在西北、华北、华中和四川盆地等地。

The method comprises: 1 when GSM module needs to select a network, it firstly decides if there is a 900 MHz frequency range network capable of meeting the communication need; if yes, then selecting the 900 MHz frequency range network as the working network of the dual-mode mobile phone; otherwise, entering the step 2; 2 deciding if there is a 1800 frequency range network; if not, then returning the step 1 to reselect network; if yes, then selecting 1800 frequency range network as the working network of the dual-mode mobile phone.

本发明公开了一种PHS及GSM双模手机中GSM模块择网的方法，涉及无线通信领域，为解决PHS及GSM双模手机不同网络间信号干扰而提出，采用的技术方案为：(1)GSM模块需要择网时，首先判断是否存在满足通信要求的900MHz频段网络，若存在则选择该900MHz频段网络作为所述双模手机的工作网络，否则进入步骤(2)；(2)判断是否存在符合通信要求的1800MHz频段网络，若不存在则返回步骤(1)重新择网；若存在则选择1800MHz频段网络作为该双模手机的工作网络。

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。

YFL is based on rich technological capability,absorbed professional development and production ultra audio frequency,high frequency,high frequency,intermediate frequency respond to the heating device.

英福伦以雄厚的技术实力为基础，专业专注于研制生产超音频，高频，中频感应加热设备。

Bob Eckert has been chairman and chief executive of Mattel for eight years.

美泰董事长兼首席执行官鲍勃·埃克尔特在任已8年。

The outlook for honors and disgraces carries on and surpasses the traditional outlook for honors and disgraces theoretically, and carries on and develops the theory of construction of socialist mora...

社会主义荣辱观的提出在理论上是对传统荣辱观的一次继承和超越，是对社会主义道德建设理论的继承和发展，在实践上有利于形成良好的社会风尚。