查询词典 radio frequency

There are keyboard and liquid crystal to demonstrate window on the frequency converter's control of face, but it can only realize manual operation, for realize the automatic control so we introduce SCM technology, as the result, between MCU and the frequency changer data communication can enhance the control ability and area of the frequency changer.

随着变频调速技术的发展，变频器调速已成为交流调速的主流，在化纤、纺织、钢铁、机械、造纸等行业得到广泛的应用。变频器控制面板上配有键盘及液晶显示窗口，但只能实现手工操作，为了进行自动化控制，因此引进单片机技术，实现单片机与变频器之间的数据通信，提高变频器的控制能力和控制范围。

This text mainly is to panorama video frequency picture, the usage partitions new calculate way automatically according to the video frequency object of timespace consociation at preparing processing stage's ash to video frequency sequence degree diagram to carry on a partial contrast degree to strengthen a processing, increasing foreground object and the contrast degree of background, the filter which passes 3 ×s 3 templates filters in addition to contrast degree strengthen after of lead go into of a little amount 噪 voice;Then aim at the circumstance of complicated background, the calculate way in the text puts forward the covariance characteristic backlog which makes use of immediately signal to get the background that the calculate way needs, overcoming the irregularity that the handicraft obtains background, carrying out a background information to obtain automatically;The standpoint put forward a background backlog finally to categorize a discussion in the process, solved object stop sport time is longer result in the partition throw the problem for losing.

本文主要是对全景视频图像，运用基于时空联合的视频对象自动分割新算法，在预处理阶段对视频序列的灰度图进行局部对比度增强处理，增加前景物体与背景的对比度，通过3×3模板的滤波器滤除对比度增强后的引入的少量噪声；然后针对复杂背景的情况，文中的算法提出利用随即信号的统计特性积累得到算法所需的背景，克服手工获取背景的弊端，实现背景信息的自动获取；最后提出背景积累过程中分类讨论的观点，解决了物体停止运动时间较长时造成分割丢失的问题。

In this system,the VVVF(variable voltage variable frequency) control method based on magnetic flux trajectory is applied.In the system,it is the target for the magnetic flux linkage polygon to be greatly approximate to the ideal magnetic flux circle.Considering such limitations as the low speed torque ripple,high speed real time and the working frequency of switching element,through the subsection synchronization control method by applying different numbers of magnetic flux linkage polygon for different frequency range,the perfect precision specifications for speed can be obtained.

系统采用基于磁通轨迹法的他控式变频调速方案，以磁链多边形尽量逼近理想磁通圆为目标，并考虑低速转矩脉动、高速实时性和开关元件的工作频率限制等约束条件，通过采用分段同步控制方式，在不同的频段采用不同的磁链多边形边数，使系统获得了优异的转速精度指标。

zinc oxide non-linear resistance of series discharge gap ; power frequency discharge voltage ; power frequency discharge current ; power frequency discharge criterion

图1为TBP的等效图间隙的放电电压即TBP的保护

Main applicability: Welding of the miamond knife head, the carbide alloy saw bit , machine work use carbide alloy cutter welding, if the cutting tool welding such as miamond cutter , drilling tool , lathe tool , shaper tool , milling cutter , broach; Standard piece , hot bolt rammer, if high-strength bolt , nut etc.; Hardware implement , handwork implement heat treatment, if tongs , spanner , whorl utensil , hammer , axe; The accessory high frequency quenching sells the various automobile accessory , motorcycle at reduced prices, such as: Crank shaft , connecting rod , wrist pin , crank pin , sprocket , axial cam , air valve , various rocker arm , rockshaft; Within speed change box, the various gear wheel , castellated shaft , biography prop up high frequency quenching treatment such as half axes , various small axis , various shift fork; The part heat treatment , the high frequency quenching that the gear wheel , sprocket , various axis , castellated shaft , pin wait for if various handle metal; Mssingle of face slide way quenching sells machine tool industry machine at reduced prices waiting.

主要适用范围：金刚石刀头的焊接，硬质合金锯片、机械加工用硬质合金刀具的焊接，如金刚石刀具、钻具、车刀、刨刀、铣刀、铰刀等刃具的焊接；标准件、螺栓的热镦，如高强度螺栓、螺帽等；五金工具、手工工具的热处理，如钳子、扳手、旋具、锤子、斧头；各种汽车配件、摩托车配件的高频淬火处理，如：曲轴、连杆、活塞销、曲柄销、链轮、凸轮轴、气门、各种摇臂、摇臂轴；变速箱内各种齿轮、花键轴、传支半轴、各种小轴、各种拨叉等高频淬火的处理；金属零件的热处理，如各种齿轮、链轮、各种轴、花键轴、销等的高频淬火处理；机床行业的机床床面导轨的淬火处理等。

The project proposed and established the strict unique mathematical model of instantaneous frequency aiming at the currently existed problems in Hilbert Huang Transform form the viewpoint of physical connotative meaning; proposed and established the strict mathematical model of general intrinsic mode signal based on the concept of general continuous intrinsic mode signal and the compositive principle of practical general intrinsic mode signal; researched and proposed the fitting method of envelope lines in HHT from the viewpoint of theory, conquered the blindness and random in quondam EMD envelope line fitting and boundary treatment; developed a virtual time-frequency analyzer based on general intrinsic mode signal decomposition to open out the local time-frequency characteristics of nonlinear and nonstationary signal more deeply and accurately.

本项目针对希尔伯特-黄变换现阶段存在问题，从物理内涵的角度提出并建立了瞬时频率严格的唯一的数学模型；基于连续性的一般固有模态信号的概念和实际信号的一般固有模态信号的组成原理，提出并建立了一般固有模态信号严格的数学模型；从理论角度研究并提出HHT中的包络线构造方法，克服了原EMD的包络线构造和边界处理的盲目性和随意性；研发一台基于一般固有模态信号分解的虚拟式时频分析仪，使之可以更深入、准确地揭示非线性非平稳信号的时频局部特征。

To resist multipath and ISI in acoustical communication, a single filter receiving method and a new method, namely preprocessing frequency hopping filtering method, were adopted simultaneously. A controlled preprocessing frequency hopping filter was added before mixing frequencies of signal receiving system to strengthen resistance against multipath and ISI. The method was simulated respectively on two frequency hopping sequences of PN code and increasing sequence.

除了采用以往的单一滤波接收处理方法，本文还采用了一种新的接收处理方法，即前置跳频滤波接收处理方法，与其他方法不同的是在信号接收系统的混频之前增加了可控的前置跳频滤波器，可以增强抗多途和码间串扰能力，并对此方法分别采用PN码和递增序列2种跳频序列进行仿真研究。

Common induction motor variable frequency system is extensively applied, but common induction motors are designed by constant frequency and constant voltage, when the frequency change that induction motor works, the parameter and performance of common induction motor will change.

摘要普通交流异步电动机变频调速系统被广泛应用，但是，普通交流异步电动机都是按恒频、恒压设计的，在频率改变时，电动机的参数和性能都将发生改变。

For this reason, an optimal automatic timing control algorithm is proposed, that can restrain the switching frequency in a certain range to achieve the purpose of high efficiency and energy conservation. Taking such factors as inductive reactance at AC side, switching frequency, harmonic distortion rate and switching loss as well as the interaction among them into consideration, the formulas for inductive reactance and switching frequency are given; then by use of digital signal processor TMS320F2812, a prototype based on the proposed algorithm is implemented, and using this prototype the effectiveness and practicality of the proposed method are verified by experimental research and simulation.

文章提出了自动定时控制的优化算法，将开关频率限定在一定范围内，以达到高效节能的目的；综合考虑交流侧感抗、开关频率、谐波畸变率和开关损耗等指标，提出了主电路电感参数和开关频率的选择公式，并采用TMS320F2812数字信号处理器构造了试验样机，进行仿真和试验研究，其结果证明了该方法的有效性和实用性。

And infrequency domain it is normally describes by the frequency responsefunction. The frequency response range is always limited, especially isthe main factor of the frequency response of the system.

传感器及测量系统的频响范围总是有限的，特别是传感器的频响范围往往是限制整个系统频响的主要环节。

Listen,point and check your answers.

听，指出并且检查你的答案。

Warming needle is one of effective treatment methods for knee arthralgia aggravated by cold,and it is simple,safety,so it should be developed in clinical acupuncture and moxibustion extensively.

但以本院科针灸门诊在2005年1月—2006年6月期间共收治膝痛患者100余例，经过临床的诊断后，其中施以温针治疗的48例，疗效显著，报道如下。1临床资料本组病例48