查询词典 short wave

And by applying the linear dispersion relation of wave, all the properties of wave refraction including wave rays, constant phase lines, phase function and crest lines etc., can be expressed in explicit functions. By introducing an orthogonal curvilinear coordinate along the wave ray and the constant phase line, and with an estimated scale factor, the refraction coefficients along any wave ray can then be determined. The present results are verified by ordinary wave ray theory and some previous numerical results.

就此特例情况在波浪的线性分散关係的应用下，前进波浪折射现象的整体特性，包括波向线、等位相线、位相函数与波峰线皆被导述出明確显然的函数表示；同时引入由沿著波向线与等位相线所构成的完全符合波浪折射几何通性的正交曲线座標，求出其尺度因子后，由能通量守衡原则定出沿著任一条波向线上的折射係数；並由之对往昔纯依两相邻的波向线间的几何类比所给定的折射係数给予导証之。

Based on the research of torsional wave and flexural wave of the transmission shaft , this paper obtained expression of theirs on the sine wave , the cosine wave , the exponential decrease wave , the exponential decrease seiche wave .

针对急剧冲击和大范围转动的特点，将圆柱体转动能量传输信息模型扩展建立在相对论基础上，建立了相对论性转动能量传输信息模型及其在不同坐标系下的转换模型。

In order to probe the absorb coefficients of earth medium by the direct wave, reflected wave and transmied wave amplititude which are picked up from the radar wave racords yielded by finite element method,the paper gives out the attenuated radar wave equations in time domain and the attenuated radar wave differential equations while the motion changes simple harmonic with time and electric parametets change slowly with space.

摘 要 为了用有限元方法生成雷波正演记录，从而拾取直达波、反射波、透射波振幅信息，以确定介质吸收系数，文章在时间域给出了雷达波含衰减项的波动方程，及在运动随时间简谐变化以及电性参数随空间缓变的条件含衰减项的雷达波遵循的简化微分方程。

The shoaling wave height is related to wave steepness. Comparing with wave theories the shoaling coefficient of small amplitude wave theory_ which is not related to wave steepness, disagrees with experimental reset. The experimental result has the trend with Stokes third order shoaling theory, but Stokes wave theory overestimates the shoaling coefficient .

波浪之浅化波高与波浪尖锐度有关，微小振幅波理论中浅化波高与波浪尖锐度无关与实测值不符，实验结果在定性上与Stokes波三阶浅化理论有相同之趋势，但在定量上实验之浅化系数较小，理论值有高估的现象。

The earliest change of ERG in birdshot chorioretinopathy was the prolongation of cone ERG implicit time. Followed by the decrease of dark-adapted b wave amplitude. The b wave amplitude of cone ERG decreased later. The duration of the disease correlates with the amplitude of b wave in the same patient. The a wave was the last affected and the decrease of the a wave amplitude was disproportionate compared to that of b wave, revealing a typical negative type ERG.

结果发现最早的变化为锥细胞ERG潜伏期的延长；接着是暗适应b波振幅下降，锥细胞b波下降较晚，同一患者病程的长短和ERG b波振幅下降幅度一致；a波振幅下降晚于b波，且下降不成比例，出现负相ERG，可作为诊断此疾病的特征性ERG。

The numerical result shows that this method can correctly and quickly separate pure compress wave and pure shear wave from hybrid wave field with high precision, good boundary absorption, and the numerical process is stable, so it can be used to guide multi-wave multi-components seismic datum processing, and also point out that the method has difficulty to separate the coupled wave type such as surface wave.

数值模拟结果表明，该方法能够从混合波场中准确地分离出纯纵横波波场，且精度高，边界吸收效果好，计算速度快，计算过程稳定，可用于指导实际多波多分量地震资料处理，同时指出本文算法对相互耦合的波型无法实现准确分离。

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。

In addition, the Chinese CRT TV screen points of light, depending on the magnetic field changes in the tilt, So with the need to control the current ramp, triangle wave, This is the same square wave can not ignore the role of function generator is generally automatically generate square wave, sine wave, saw tooth wave and triangular wave, etc. ladder circuit voltage waveform or equipment.

此外，如在电视机中显像管荧光屏上的光点，是靠磁场变化进行偏转的，所以需要要用锯齿波电流来控制，对于三角波，方波同样有这不可忽视的作用而函数发生器是指一般能自动产生方波、正弦波、三角波以及锯齿波阶梯波等电压波形的电路或仪器。

Based on aforementioned findings, the author disclosed China have gone through three wave of marketing since the open policy reform in the end of seventies in the last century: the first wave taken place from the end of seventies to the end of eighties of last century, during this period of time, enterprises commonly took a marketing tactics mix of unitary product, high gross-profit pricing, wholesale and information notification; the second wave happened from the end of eighties to the end of nineties in the last century, during the second wave, enterprises often took a marketing tactics mix of serialized products, medium gross profit pricing, regional distribution and advertisement on mass media; the third wave occurred from the end of nineties of last century to now, during the third wave, enterprises usually adopted a marketing tactics mix of segmented products, low gross profit pricing, outlet interception and tangible benefits promotion.

基于上述认识，本书进而揭示出，中国市场自上个世纪70年代末改革开放以来，已经经历了三次营销浪潮：第一次营销浪潮发生在20世纪70年代末至80年代末，期间，企业界普遍采取的是&单一化产品+高毛利政策+批发销售+信息告知&的链接标记营销策略组合。第二次营销浪潮发生在20世纪80年代末至90年代末，期间，企业界普遍采取的是&系列化产品+中毛利政策+区域链接标记分销+大众链接标记广告&的营销策略组合。第三次营销浪潮发生在20世纪90年代末至今，期间，企业界普遍采取的是&细分化产品+低毛利政策+链接标记终端拦截+实惠促销&的营销策略组合。

Based on aforementioned findings, the author disclosed China have gone through three wave of marketing since the open policy reform in the end of seventies in the last century: the fi rst wave taken place from the end of seventies to the end of eighties of last century, during this period of time, enterprises commonly took a marketing tactics mix of unitary product, high gross-profit pricing, wholesale and information notification; the second wave happened from the end of eighties to the end of nineties in the last century, during the second wave, enterprises often took a marketing tactics mix of serialized products, medium gross profit pricing, regional distribution and advertisement on mass media; the third wave occurred from the end of nineties of last century to now, during the third wave, enterprises usually adopted a marketing tactics mix of segmented products, low gross profit pricing, outlet interception and tangible benefits promotion.

基于上述认识，本书进而揭示出，中国市场自上个世纪70年代末改革开放以来，已经经历了三次营销浪潮：第一次营销浪潮发生在20世纪70年代末至80年代末，期间，企业界普遍采取的是&单一化产品+高毛利政策+批发销售+信息告知&的营销策略组合。第二次营销浪潮发生在20世纪80年代末至90年代末，期间，企业界普遍采取的是&系列化产品+中毛利政策+区域分销+大众广告&的营销策略组合。第三次营销浪潮发生在20世纪90年代末至今，期间，企业界普遍采取的是&细分化产品+低毛利政策+终端拦截+实惠促销&的营销策略组合。

According to our present broadcasting situation,the thesis proposes using new technology to update and reform the present HFC. It also suggests broadcasting using self-advantage and arranging EPON in order to win the supermarket.

论文从我国广电的现状出发，结合实际，积极倡导采用新技术更新、改造我国现有的HFC网络；倡导广电现阶段利用自身优势，部署EPON网络来赢取市场。

A new general kinetic equation was derived in which the effect of the removal of condensation water was taken into account completely, and was applied to the polyesterification kinetic study of AA/HPHP and AA/NPG. It was found that the reaction order of self-catalyzed polyesterification was not constant. For these polyesterifications, the reaction order was 2.5 at a low temperature, while 3.0 at a high temperature.

考虑缩合水的排除对反应体系的影响，用体积浓度单位推导出一个新的聚酯反应总包动力学方程，并应用到AA/HPHP和AA/NPG两个聚酯化反应的动力学研究中，研究发现，自催化聚酯反应的反应级数并不是固定值，对于AA/HPHP和AA/NPG两个聚酯化反应而言，低温时反应级数为2.5，高温时反应级数为3.0。