查询词典 harmonic integrals

In Chapter 6, by using the matrix models of 3-dimensional Minkowski space R〓, first we study deformation properties and integrablilities on spacelike surfaces with a harmonic inverse mean curvature and timelike surfaces with a Lorentz harmonic inverse mean curvature.

在第六章中，首先借助三维Minkowski空间R〓的矩阵模型，研究了R〓中具有调和逆平均曲率的类空曲面和洛伦兹调和逆平均曲率类时曲面的可积性及其形变。

Results indicate that:(1) by using HANTS, the researchers could get the EVI/NDVI harmonic curves, the mean VIs and the amplitude of the harmonics which then were utilized in the identification of the cultivated land, and EVI appeared to be more precise, with the overall accuracies of 97.17% and 95.99% and Kappa coefficients of 0.7938 and 0.6518, respectively.(2) Multiple cropping index was extracted by counting the number of the curve's peak; and when the threshold of the peak value of the NDVI and EVI curves were set as 0.25 and 0.20, respectively, the fallow land could be well figured out.(3) From harmonic curves, some eigenvalues, such as time of the maximum growth rate, time of peak and the value of peak can be extracted, based on which the crop types can be primarily distinguished. And EVI still performed better than NDVI in this section.

结果显示：（1）利用傅立叶谐波变换得到的EVI和NDVI时间谱曲线的谐波余项及谐波振幅对耕地进行识别，从识别精度来看，EVI要优于NDVI，识别精度分别为97.17%和 95.99%，Kappa系数分别达到0.7938和0.6518；（2）通过计算时间序列曲线的波峰数能够提取耕地的复种指数，并且在EVI和NDVI曲线波峰阈值分别设为0.20和0.25时，休耕地能较为准确地被识别出来；（3）通过提取作物生长期内曲线的VI最大增长速率时间点以及峰值时间点等信息，作物种类能被初步识别，并且EVI较NDVI具有更强的识别能力。

Detect and measure harmonic is needed to control harmonic.

要抑制谐波，必须对谐波进行检测和测量。

Harmonic measure method is the key of the measurement. In this paper, the harmonic measure method which based on the multiple frequency rotate transform theory is researched and analyzed.

谐波测量方法是谐波测量的核心环节，本文对基于倍频旋转变换理论的谐波测量方法进行了研究分析。

Keywords: Harmonics, active power filter, Fourier Algorithm, Harmonic analysis and measure, Harmonic prevention

谐波，有源滤波器滤波器，傅立叶变换，谐波分析测量，谐波抑制

Traditional instrument in harmonic measurement is the transformer with circularity form core coil, but it is influenced by direct current and saturated, so it could not be used to measure direct harmonic current.

基于Rogowski 线圈的光电直流谐波电流测量系统解决了传统谐波电流测量受直流分量影响的难题，是集光纤技术、电子技术、激光技术于一体的新型谐波电流互感器。

Because the harmonic is harmful to the electric net and electrical equipment, it is very important to measure the harmonic accurately and restrain it. Some methods for harmonics measurement are proposed in these years.

由于谐波对电网及用电设备有诸多危害，准确测量谐波及抑制谐波就显得尤为重要。

Use the Rogowski coil as the sensor and transmit the signal and energy with the optic fibre, analyse the principle of the measurement of harmonic current in HVDC system and the factors of its measurement of influence by opticelectricity and computer technology. The Rogowski coil is used to measure the harmonic current in HVDC system. It doesnot affect by direct current and has good frequency characteristics.

本文在全面分析高压直流谐波电流测量方法的基础上，确定以空心线圈为传感器，以光纤传输信号和能量，结合光电技术、微计算机技术，系统地分析了谐波电流测量系统的工作原理及影响其测量的多种因素，提出了解决问题的具体方法和措施。

In this dissertation, digital lock-in detection techniques under integer period sampling and non-integer period sampling are separately investigated (1) Under integer period sampling, digital signal sequence is acquired through sampling the measured signal, but digital reference sequence is acquired through mathematical operation, then digital lock-in detection can be realized by calculating crosscorrelation function of digital signal sequence and digital reference sequence Harmonic measure is also analyzed, and a method of measuring harmonic of a periodic signal under aliasing is put forward.

本文对使用采样ADC把模拟信号转换为数字信号并通过计算数字信号的相关函数来实现锁定检测的技术进行了研究，在此基础上设计了一个多功能的数字LIA并在一些科学实验中进行了应用。本文对整周期采样和非整周期采样时的数字锁定检测技术分别进行了研究。(1)在整周期采样时，对被测信号进行采样得到信号序列，而参考序列由数学运算得到，通过计算信号序列和参考序列的互相关函数就可实现锁定检测。

Based on this system, harmonic and subharmonic periodic response of S-LF subjected to harmonic motion is investigated by using Floquet theory.

并给出了这种结构的最大滑动位移响应随滑移面摩擦系数的变化曲线，可供设计时参考。

There are different types of personal loans available.

有许多不同类型的个人贷款优惠。

The above mentioned teaching model of spiral rising can be used to avoid rigidness in teaching.

上述螺旋式上升的教学模式，可以避免教学形成模式後的僵化现象。