查询词典 harmonics

Comparision of the monthly value of ΔC20,ΔC30,ΔC40m,ΔC50 estimated from CHAMP GPS data over one year shows periodic vibration. That is, computing gravity field recovery error in low degree zonal harmonics can effectively present the temporal variation.

求得两部份低阶地谐系数差值ΔC20，ΔC30，ΔC40，ΔC50的变化值，四张图形趋势都约略呈现周期性变化，也就是说从CHAMP低轨卫星资料计算重力，的确可以看出重力球谐系数的时间变化。

Numerical calculations show that when azimuthally asymmetric space harmonics increases, the start oscillation length decreases, and that it is possible to increase the start oscillation length by tailoring magnetic field's amplitude and its period.

四、在抑制返波振荡的方法中，改变聚焦磁场是一种比较好的方法，因为改变聚焦磁场几乎不会改变前向波的互作用条件，而会改变返波的互作用条件，因而既可以对返波振荡进行很好的抑制，又有利于提高效率。

It shows that it is possible to increase the start oscillation length by tailoring magnetic field's amplitude and its period without changing the synchronous condition of the fundamental wave; in the meantime, when there are two or more azimuthally asymmetric space harmonics in the high power broad-band helix TWTtraveling wave tu...

与此同时，对起振长度、初始非同步速度参量随皮尔斯增益参量、空间电荷参量、损耗参量等的变化，以及在超宽带行波管中当存在两个或多个角向非对称空间谐波时，起振长度、初始非同步速度参量随周期永久聚焦磁场的变化进行了研究。优化设计聚焦磁场、电子注和螺旋线慢波系统的参量可以对螺旋线行波管的稳定性分析提供必要的依据。

It shows that it is possible to increase the start oscillation length by tailoring magnetic field's amplitude and its period without changing the synchronous condition of the fundamental wave;in the meantime, when there are two or more azimuthally asymmetric space harmonics in the high power broad-band helix TWT, the influences of the Pierce's gain parameter, space charge parameter, and loss parameter on the start oscillation length and real starting asynchronous velocity parameter are also analyzed.

研究结果表明：改变聚焦磁场的幅值或周期来增加起振长度是可能的，而且不会改变基波的互作用条件。与此同时，对起振长度、初始非同步速度参量随皮尔斯增益参量、空间电荷参量、损耗参量等的变化，以及在超宽带行波管中当存在两个或多个角向非对称空间谐波时，起振长度、初始非同步速度参量随周期永久聚焦磁场的变化进行了研究。

In the dissertation, we presented a method to calculate the start oscillation length and real starting asynchronous velocity parameter. In the meantime, when the effect of two or more azimuthally asymmetric space harmonics in the high power broadband helix TWT on the start oscillation length and real starting asynchronous velocity parameter were also analyzed.

数值计算表明：增大渐变的强度，就可以增加起振长度，而且当渐变的强度增大到一定值时就不会产生返波振荡；当衰减器靠近输入段时，起振长度就随之减小；当增大衰减器的长度或减小衰减量时，相对起振电流随之减小，可见衰减器对起振条件确实有明显的影响。

During the period of the activity of reforming the traditional calendar, Xing Yunlu only reformed the calendar according to the calendar idea established in his book Gujin Lüli Kao (GJLLK, Investigation into Harmonics and Calendrical Astronomy from Antiquity to the Present, c.1600). Combined with the analysis of Xing Yunlu's eclipse records collected from the Mingshilu (True Records of the Ming Dynasty) and Mingshi, we pointed out that Xing Yunlu's had not made ultimate improvement to the traditional calendar in his activity of calendar reform.

结合对邢云路在钦天监参预改历活动中预报日月食记录精度的分析，指出：以邢云路为代表的传统历法家在钦天监进行的历法改革总体来说起色不大，除在个别月食预报以及日食食分的预报结果上好于《授时历》的预报结果外，其他预报结果的精度均不如《授时历》，而且从总体上看邢云路新法的水平还不如当时行用的《大统历》，尤其是邢云路预报天启元年四月朔(1621年5月21日)日食出现差错而宣告了他依据传统历法进行改历努力的失败。

C. electric parameters measurement. The means and conditions to reestablish the signal without distortion are also given. At last, this paper discusses the theoretical basis for power, RMS and harmonics phase measurements of power system directly from the Harr wavelet matrix transform data associated with each sampling voltage and current element pair.

本文针对电力系统特点，分析了非均匀采样的数字频谱结构及非均匀采样周期信号的数字谱表达式，并讨论了非均匀采样对交流电量参数测量的影响，给出了非均匀采样无失真恢复信号的方法和条件。

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 numerical simulation shows that the harmonics at the end of the plateau become continuous and form a supercontinuum with a bandwidth of about 80 eV, from which a 50 as isolated pulse in the transform limited case can be generated, when asymmetric molecules are exposed to a multicycle two-color field, which is synthesized by a 10 fs/800 nm fundamental pulse and a 15 fs/1200 nm control pulse.

通过计算机数值模拟，发现当波长为800 nm，脉宽为10 fs的基频场和波长为1200 nm的控制场组成的多光周期双色场作用于不对称分子时，不对称分子的高次谐波在平台区的末端呈现出光滑的超连续结构。超连续谱谱宽达80 eV，可以支持傅里叶极限脉宽为50 as的单个脉冲输出。

Therefore, the exact relation between the unbalanced input voltage and the noncharacteristic harmonics of the output voltage in the 12-pulse rectifier system is obtained. In addition, the relation between the input current and the imbalance of the input voltage is obtained, which could help to choose the filter elements and exactly analyze the characteristics of the no controlled rectifier circuit.

利用精确的开关函数，推导了多脉波整流系统输入不平衡电压与输出电压非特征谐波的精确关系，进而得到电阻、电感负载时系统输入电流与输入电压不平衡度的关系，为精确地选择滤波元件做了有意义的探索。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。