正弦波

Standard waveforms include: sine, square, triangle, dc, positive ramp, negative ramp, sine/x, pulse, pulse train, cosine, haversine and havercosine.

标准波形包括：正弦波，方波，三角特区，积极坡道，消极坡道，正弦/十，脉冲，脉冲，余弦， haversine和

And thus,the wavelet analysis has developed due to this demand, This thesis is to detect the point of signal discontinuity by wavelet transform.

小波分析正是由于这种需求而发展起来的通过小波变换来精确地检测信号发生变化的时刻，构造一个信号模型，由一个低频正弦波信号连接一个高频正弦波信号，利用小波工具可以检测出信号发生不连续的间断点的位置。

Often divided into two types:(1) sine wave oscillator, according to the network oscillation frequency of the different loop selected further divided into RC sinusoidal oscillator, LC sinusoidal oscillators, quartz crystal oscillators, voltage-controlled oscillator, voltage-controlled crystal oscillator and other forms;(2) non-sinusoidal oscillation device, also known as relaxation oscillator, is the use of capacitor charging and discharging and active device (transistor, FET, single-junction transistor, etc.) to generate the pulse-off square wave, rectangular wave, triangle wave, sawtooth wave, or these basic waveforms synthetic waveform and its frequency by the LC time constant charge and discharge circuits to decide.

常分两大类型：（1）正弦波振荡器，根据振荡环路中选频网络的不同，又分为RC正弦波振荡器、LC正弦波振荡器、石英晶体振荡器、压控振荡器、压控石英晶体振荡器等多种形式；（2）非正弦波振荡器，又称张弛振荡器，是利用电容充放电及有源器件（晶体管、场效应管、单结晶体管等）的通断来产生脉冲方波、矩形波、三角波、锯齿波或这些基本波形的合成波形，其工作频率由LC充放电电路的时间常数来决定。

With the id￠=0 vector control and the feedforward compensation of cogging, the minimum force ripple and maximum efficiency control of non-sinusoidal BEMF SPM motors can be obtained.

考虑永磁磁链谐波对永磁磁链导数矢量幅值及相位的影响，通过引入d￠q￠轴坐标系，提出一种id￠=0的非正弦波BEMF SPM电机矢量控制新方法，结合齿槽前馈补偿可以实现非正弦BEMF SPM电机的最小推力纹波最大效率控制。

The use of sinusoidal functions of the AD9851 and the frequency of sine wave is adjustable.

详细说明：利用AD9851的功能产生正弦波并且正弦波的频率是可调的。

We have both true sine wave and quasi sine wave types.

我们有正弦波和准正弦波两种类型。

On the basis of the RMS definition a method for measuring TRMS of distortion sinusoid or non-sinusoid is introduced in the paper.

介绍了一种基于交流信号有效值定义测量失真正弦波或非正弦波真有效值的方法，解决了平均值法在测量失真正弦波时引起显著测量误差的问题。

This instrument generated the sine wave signal which frequency could change in three situations. The sine wave signal inputted to the buffer amplifier, then divided into two groups, a group connected with oscilloscope to survey the peak-to-peak value of fundamental wave, another group connected with wave trap to filter out the fundamental wave, then the oscilloscope was used to survey the various sub-harmonics amplitude of the output.

该仪器是通过设计可变三种频率的正弦波信号发生器产生的正弦波信号，其输出信号经过缓冲放大器，输入放大器后分为两路，一路接入示波器，测量基波幅值；另一路接入陷波器将基波滤去，再用示波器测量其输出各次谐波幅值。

From the angle of a beam-forming, the cross- range focusing principle of the synthetic-aperture radar based on nonsinusoidal waves is studied. The expressions of antenna pattern for both rectangular signa l and Gaussian signal are presented. Compared with the conventional narrow bandw idth SAR whose cross-rang resolution is determined by the carrier frequency, th e cross-range resolution of the nonsinusoidal SAR is affected by the signal ban dwidth.

为研究非正弦波SAR的方位向分辨力，从波束形成的角度分析了非正弦波SAR的方位向聚焦原理，导出了基于矩形脉冲和高斯脉冲的合成孔径天线阵列方向图表达式，并与常规窄带SAR进行比较，指出影响非正弦波SAR方位向分辨力的主要因素为合成孔径长度和信号带宽，而与信号载频无关。

The article presents the developing condition of PWM and SVPWM first.Then the theory of SVPWM is discussed in detail.The SVPWM is based on the thought of magnetic chain tracking.It makes the ideal magnetic chain circle of three-phased sysmmetry electric motor supplied by three-phased sysmmetry sine wave voltage for basis,uses the practical magnetic chain vector formed by the different switch modes of three-phased inverter to track the basic magnetic chain circle.During the course of tracking,the inverter changes the switch modes properly to form the PWM waves.Then the modulation wave of SVPWM is analyzed in detail.The modulation wave of SVPWM is implicit,but the analogous modulation wave in A-B-C axis needs to be calculated in order to expose the internal relation of SVPWM and SPWM.That is to show the implicit modulation wave of SVPWM. SVPWM actually is a transformed SPWM ruly sampled by the modulation wave which is injected by the zero prefaces based on space vectors.

本文首先对脉宽调制技术的发展现状进行了综述，在此基础上分析了电压空间矢量脉宽调制技术的发展现状；接着对空间电压矢量脉宽调制技术的基本原理进行了详细的分析和推导，SVPWM是基于磁链追踪的思想，它以三相对称正弦波电压供电下三相对称电动机定子理想磁链圆为基准，由三相逆变器不同开关模式下所形成的实际磁链矢量来追踪基准磁链圆的，在追踪的过程中，逆变器的开关模式作适当的切换，从而形成PWM波；然后详细分析了电压空间矢量脉宽调制技术的调制波，虽然SVPWM法的调制波是隐含的，但是为了揭示SVPWM法与SPWM法的内在联系，需要求出SVPWM在A-B-C坐标系上的等效调制波，也就是将SVPWM的隐含调制波显化；SVPWM实质是一种基于空间矢量在三相正弦波中注入了零序分量的调制波进行规则采样的一种变形SPWM。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。