查询词典 frequency

Some methods, in which synthesized theoretical seismogram of high frequency is taken as record signal and 20%random noise is superimposed on the seismogram, are used to analyze the theoretical seismogram. The digital experiment shows that in the correlating frequency range, Green's function method can measure precisely interstation phase velocity, but the results obtained by correlation and narrow band-pass filtering correlation methods are more dispersed.

以合成的高频理论地震图作为记录信号，并在理论地震图上叠加了20％的随机噪声，利用这些方法分析理论信号，数字实验表明：在相干频率范围内，格林函数方法能够精确测量台间相速度，而互相关法和窄带通滤波互相关法所得结果较为离散。

This paper firstly introduced the current popular feature selection methods based on term frequency and inversed document frequency.

而如何进行邮件特征选择，是邮件分类中的重要问题。

Having analysed notonly the frequency characteristics of signal and random noise but also influence ofnoise upon filter under different signal/noise ratios, authors studied noise elimina-tion using inversion in wavelet trans form domain and then advance frequency- divi-sional inversive noi.

本文通过分析信号与随机噪声的频率犄性及在不同信噪比情况下噪声对滤波器的影响，研究了小波变换域中的庆演去噪情况，提出分频反演去噪方法。

And the low frequency vibrations contribution from ring A and oxygens to the internal reorganization energy of MQ〓(n=1～7) is greater than 1.60kJ.mol〓 in addition, the low frequency vibrations contribution from the isoamylene substituent to the internal reorganization energy of MQ〓 and MQ〓 is about 2.0kJ〓.

得电子前后，环A及对位氧的二面角变化对质体醌MQ〓(n=1～7)的内重组能的贡献大于1.60kJ.mol〓，而且得电子前后，异戊烯支链结构参数的变化尤其是二面角的变化对MQ〓／MQ〓及 MQ〓/MQ〓体系的内重组能贡献约为2.0kJ-mol〓。

The Hilbert amplitude envelope of the stator current includes the low frequency of fault characteristic, thus it can reduce the signal length by resample the Hilbert amplitude envelope of the stator current by downsampling, which can avoid spectrum aliasing. Then it can reduce the computation time of the MUSIC Method for the spectrum analysis to the resampled signals for the given bandwidth. Meanwhile combining continuous subdivision Fourier transform and rotor slot harmonics based slip estimation it can in advance estimate the concrete values of the fault characteristic frequency, and then inquiry purposely the fault feature component information in the stator current spectrum in order to accomplish the broken rotor bar fault with high sensitivity and h reliability, which eliminates adverse effect of issuable false peaks to the fault detection and formed a novel scheme to detect broken rotor bar fault.

定子电流Hilbert幅值包络信号包含了低频的故障特征频率调制信号，故通过对定子电流Hilbert幅值包络信号进行降采样率重采样、减少分析信号长度，可避免低频段频谱混叠，再对减少的重采样数据进行具有超分辨率的MUSIC低频段估计，可大大降低MUSIC算法频谱估计时间；运用连续细化傅里叶变换和转子齿槽谐波转差率估计技术，可预知故障特征频率精确值，从而可有目的地查询故障分量，消除MUSIC虚假波峰对故障检测混淆的影响，大大提高了故障检测的灵敏度和可靠性，以此形成异步电动机转子断条故障检测新方法。

The function of railway is very important in our country's economic development, in order to accelerate the development of our country's economy, the Ministry of Railway has developed two kinds of frequency-shift track circuits: 18-information frequency-shift auto-blocking track circuit and UM-71 jointless track circuit, and put them into use on some important lines.

铁路在我国经济发展中发挥着重要作用，为了加快经济的发展，铁道部根据我国国情，研制开发了两种移频轨道电路：18 信息移频自动闭塞系统和UM-71 无绝缘轨道电路，并将其应用到我国部分主要线路上。

Results showed that DCF with different dosages could increase the frequency of micronucleated erythrocytes markedly,except the first injection of the dosage with 5 and 10 mg/kg,every group caused an increase in the frequency of nuclear abnormality erythrocytes,the effects in cell membrane and cytoplasm were less than the effects in karyon by DCF,and the most toxicity was exhibited after the second injection.

结果表明，注射DCF后所有剂量组均能引起中华蟾蜍红细胞微核细胞率显著升高；除5，10mg／kg剂量组在第1次注射后较对照组低外，其他注射剂量和次数均引起核异常细胞率升高，DCF对细胞膜与细胞质的影响小于其对细胞核的影响，在4次注射中以第2次注射后对红细胞的毒性效应最大。

One of the most common ways to describe a wood's tonal properties is in terms of its frequency range,which is often broken down into low-end frequencies,mid-range and high-end frequencies.picture it as a visual spectrum,as we've done in the chart to the right,with the lower frequencies on the left and the higher frequen-cies on the right.the graph line for each wood visually depicts its general tonal range.rosewood and ovang kol,for example,tend to resonate with more low-end frequencies,whereas koa,cocobolo and maple tend to sound brighter from having more top-end frequencies.note also rosewood's"scooped"midrange and ovang-kol's fuller midrange.the doted lines for walnut and koa denote the expansion of low-end frequency range as the guitar opens up after a period of playing it.

最常见的方式描述了木材的声音特性是在其频率范围内，这往往是细分为低端频率，中端和高端frequencies.picture它作为一个视觉频谱，因为我们'维生素E这样做的图表，以权，以较低的频率在左边和更高的频率，种上right.the图线的每一个木材视觉描绘的一般音调range.rosewood和ovang科尔举例来说，往往会产生共鸣更多的低端频率，而兴亚， cocobolo和枫树往往从健全光明有更多的高端frequencies.note也花梨木的&收购&的中端和ovang -科尔的充分midrange.the doted线的核桃和兴亚指扩大低端频率范围内的吉他开辟了一段时间后，打它。

The result shows that the influence of tree species on the fundamental frequency of a soundboard is obvious. Among several tree species studied, the fundamental frequency of a ochroma lagopus soundboard is the highest, and that of a walnut soundboard is the lowest.

结果表明：不同的树种对钢琴音板基频的影响是明显可见的，在所研究的几个常用树种中，轻木音板的基频最大，而核桃木音板基频最小。

The high frequency combustion instability in liquid rocket engine LRE is analyti cally studied by usin g CFD methods.The comprehensive model and governing equations for numerical simu lation of high frequency combustion instability are presented.The PISO and MacCo rmack algorithms are compared in this study.Both methods can successfully handle combustion instability analysis.

应用CFD方法对液体火箭发动机中的高频燃烧不稳定性进行了分析研究，建立了液体火箭发动机不稳定燃烧数值模拟的综合模型和控制方程，比较了PISO和Ma cCormack两种算法，得出了两种算法均能成功应用于不稳定燃烧分析的结论。

This is not an ordinary box, which is used as a background picture of the dialog box, very pretty.

详细说明：这可不是一个一般的对话框，它是用图片作为背景的对话框，非常好看。

Conceal me what I am,and be my aid for such disguise as haply shall become the form of my intent.

遮掩我的身份，帮助我，我的面具将成为我的目的。