查询词典 frequency histogram

A novel quasi-constant frequency hysteresis PWM control approach is presented in this paper. Frequency feedback is introduced in hysteresis current control to stabilize switching frequency. Comparing with the common used constant frequency current mode control, the new approach has better stability, faster transient and higher precision, as well as elimination of sub-harmonic oscillation.

摘 要：本文提出了一种新的准固定频率滞环PWM电流控制方法，该方法在滞环电流控制的基础上，引入频率反馈控制，使开关频率基本固定，解决了目前广泛使用的固定频率电流控制方法具有的次谐波振荡的问题，并且具有稳定性好、相应速度快、控制精度高的优点。

This system ofcompatible electromagnetism of frequency spectrum has someimportant functions listed as follows:(1) Analysis disturbance of the same or adjacent frequencies (2) Analysis of performance of radio link (3) Analysis of intermodulation (4) Automatic selection of frequency(auxiliary assignment of frequency)(5) Prediction of region of radio field intensity (6) Harmonization of frequency border (7) Analysis and design the system of microwave and satellite earth station.(8) Generate photographs This paper realizes the function of harmonization analysis ofthe system of microwave and satellite earth station. The concretework includes:(1) Based on the propagation model of radio wave,computing the absorption loss of atmosphere of microwavecommunication system and its fading, simulating the receivingvoltage and realizing the computation of disturbance andharmonization between microwave station and earth station.

频谱电磁兼容分析系统主要实现以下几个功能：⑴同、邻频干扰分析⑵无线链路性能分析⑶互调分析⑷频率自动选择⑸场强覆盖预测⑹边界协调⑺微波与卫星地球站系统设计和干扰协调分析⑻图形制作功能本文做为全省建设的电磁兼容分析系统的一部分，实现了微波站与地球站干扰协调分析这一功能，具体有：⑴以无线电波自由空间传播为模型，对微波通信系统的大气吸收损耗和衰落储备量进行了计算、对接收电平进行了模拟仿真，实现了微波- I -吉林大学硕士学位论文 Abstract站与地球站之间的干扰与协调计算。

On the basis of the characteristics of line boundary, this paper analyzes the different features of internal and external faults. The difference is that the ratio of high frequency to low frequency components in case of one external fault is less than that in case of the same internal fault, in which high frequency is in the band of line trap and low frequency is within 1~10kHz.

在线路边界频率特性的分析基础上，深入地分析了区内外故障时的特征差异：就某一类故障而言，区外故障时反行波中高频分量与(1~10kHz内的)低频分量的比值显著小于区内故障时的比值。

This experiment counts based on the direct digital frequencysynthesis the basic principle, fully II and hardware LT - IV testedthe box using ALtera Corporation's FPGA chip FLEX10 in softwareMaxplus in the platform to complete the DDS system design, hasdesigned a frequency and the phase may control has the sine and thecosine output direct numeral frequency synthesizer, was allowedto control and to observe the profile through the downloading boardand the Oscilloscope , completed in the enhancement request hascontrolled the frequency and the phase through the downloading boardon pressed key, as well as many kinds of profiles, includingsquare-wave, saw-tooth wave, triangle wave and cosine wave choiceoutput, In addition on digital tube dynamic demonstration productionprofile frequency, and produces the tbl document from the simulationprofile, simultaneously draws the profile using the matlab higherorder language.

帮忙翻译一下，谢谢本实验基于直接数字频率合成计的基本原理，充分利用ALtera公司的FPGA芯片FLEX10在软件MaxplusⅡ和硬件LT—IV实验箱的平台上完成了DDS系统的设计，设计了一个频率和相位均可控制的具有正弦和余弦输出的直接数字频率合成器，通过下载板和示波器可以控制和观察波形，在提高要求中完成了通过下载板上的按键来控制频率和相位，以及多种波形，包括方波、锯齿波、三角波和余弦波的选择输出，此外在数码管上动态显示生成的波形频率，并且从仿真波形中生成tbl文件，同时利用matlab高级语言画出波形。

This experiment counts based on the direct digital oscilloscope frequencysynthesis the basic principle, fully II and hardware LT - IV testedthe box using ALtera Corporation's FPGA chip FLEX10 in softwareMaxplus in the platform to complete the DDS system design, hasdesigned a frequency and the phase may control has the sine and thecosine output direct numeral frequency synthesizer, was allowedto control and to observe the profile through the downloading boardand the oscilloscope, completed in the enhancement request hascontrolled the frequency and the phase through the downloading boardon pressed key, as well as many kinds of profiles, includingsquare-wave, saw-tooth wave, triangle wave and cosine wave choiceoutput, In addition on digital oscilloscope tube dynamic demonstration productionprofile frequency, and produces the tbl document from the simulationprofile, simultaneously draws the profile using the matlab higherorder language.

帮忙翻译一下，谢谢本实验基于直接数字频率合成计的基本原理，充分利用ALtera公司的FPGA芯片FLEX10在软件MaxplusⅡ和硬件LT—IV实验箱的平台上完成了DDS系统的设计，设计了一个频率和相位均可控制的具有正弦和余弦输出的直接数字频率合成器，通过下载板和示波器可以控制和观察波形，在提高要求中完成了通过下载板上的按键来控制频率和相位，以及多种波形，包括方波、锯齿波、三角波和余弦波的选择输出，此外在数码管上动态显示生成的波形频率，并且从仿真波形中生成tbl文件，同时利用matlab高级语言画出波形。

To complete the DDS system design, hasdesigned a frequency and the phase may control has the sine and thecosine output direct numeral frequency synthesizer, was allowedto control and to observe the profile through the downloading boardand the oscilloscope, completed in the enhancement request hascontrolled the frequency and the phase through the downloading boardon pressed key, as well as many kinds of profiles, includingsquare-wave, saw-tooth wave, triangle wave and cosine wave choiceoutput, In addition on digital tube dynamic demonstration productionprofile frequency, and produces the tbl document from the simulationprofile, simultaneously draws the profile using the matlab higherorder language.

本实验基于直接数字频率合成计的基本原理，充分利用ALtera公司的FPGA芯片FLEX10在软件MaxplusⅡ和硬件LT—IV实验箱的平台上完成了DDS系统的设计，设计了一个频率和相位均可控制的具有正弦和余弦输出的直接数字频率合成器，通过下载板和示波器可以控制和观察波形，在提高要求中完成了通过下载板上的按键来控制频率和相位，以及多种波形，包括方波、锯齿波、三角波和余弦波的选择输出，此外在数码管上动态显示生成的波形频率，并且从仿真波形中生成tbl文件，同时利用matlab高级语言画出波形。

This experiment counts based on the direct digital frequencysynthesis the basic principle, fully II and hardware LT - IV testedthe box using ALtera Corporation's FPGA chip FLEX10 in softwareMaxplus in the platform to complete the DDS system design, hasdesigned a frequency and the phase may control has the sine and thecosine output direct numeral frequency synthesizer, was allowedto control and to observe the profile through the downloading boardand the oscilloscope, completed in the enhancement request hascontrolled the frequency and the phase through the downloading boardon pressed key, as well as many kinds of profiles, includingsquare-wave, saw-tooth wave, triangle wave and cosine wave choiceoutput, In addition on digital tube dynamic demonstration productionprofile frequency, and produces the tbl document from the simulationprofile, simultaneously draws the profile using the matlab higherorder language.

涂层测厚仪-帮忙翻译一下，谢谢涂层测厚仪-帮忙翻译一下，谢谢帮忙翻译一下，谢谢本实验基于直接数字频率合成计的基本原理，充分利用ALtera公司的FPGA芯片FLEX10在软件MaxplusⅡ和硬件LT—IV实验箱的平台上完成了DDS系统的设计，设计了一个频率和相位均可控制的具有正弦和余弦输出的直接数字频率合成器，通过下载板和示波器可以控制和观察波形，在提高要求中完成了通过下载板上的按键来控制频率和相位，以及多种波形，包括方波、锯齿波、三角波和余弦波的选择输出，此外在数码管上动态显示生成的波形频率，并且从仿真波形中生成tbl文件，同时利用matlab高级语言画出波形。

In addition, the analyses of weld surface ripple and microstructure with three current waveforms have indicated that the high frequency wave group modulated by low frequency GTA welding has the advantage of both the low frequency in which the heat input of the weld pool is easily controlled and high frequency GTA welding in which the arc is energy—concentrated and stiff.

另外，通过对高频脉冲焊、低频脉冲焊、低频调制高频方波群焊不锈钢焊缝表面形貌分析表明，低频调制高频方波群焊综合了低、高频GTA焊的特点。

Instead of allocating several frequency bands block by block to a radiocommunication system, at least one frequency band of another radiocommunication system is arranged between the frequencies of the first and second frequency band, whereby a minimum distance is created between the frequency bands used in a location.

在频率分配的意义上讲，不是成块地给一个无线通信系统分配多个频带，而是在所述第一和第二频带的频率之间设置了其它无线通信系统的至少一个频带。于是在一个位置处使用的频带之间具有一个最小间隔。

Numerical simulations and analytical results show: in longitudinal and oblique seas, ship may be subjected to primary parametric resonance with large roll amplitude and even capsizing, when encounter frequency is near the twice of roll natural frequency, wave length and ship length are of the same order and the wave height is larger than a certain value; in oblique seas, ship roll motion is a forcedly-parametrically excited oscillation, primary resonance occur as the encounter frequency is near the roll natural frequency, which may lead to large rolling and capsizing too.

数值仿真和解析分析结果表明：在纵浪和斜浪中，当遭遇频率接近船舶横摇固有频率的两倍，波长和船长接近，波高超过某一阈值的时候，船舶会发生主参数共振，产生大幅横摇甚至倾覆；在斜浪中，船舶发生的是参强激励横摇运动，遭遇频率接近横摇固有频率时，还会激起横摇主共振，同样会产生大幅横摇甚至倾覆。

You can do some assertiveness training.

你可以进行一些自信训练。

We were well on the path to making a rear-wheel-drive global platform," says Mays."

我们正致力于建立一个后轮驱动的平台，"Mays这样说道。"