声变

Spectral element methods for partial differencial equation is introduced in this study from viewpoint of the collocation approximation of Chebyshev polynomial. Wave Equation and its space discretization are deduced. Two time integral methods, central difference method and implicit Newmark method, are introduced, and their stability and applicability are also discussed in some details. The significance of absorbing boundary conditions in spectral element methods for Aeroacoustics is explained, and Clayton-Engquist-Majda absorbing boundary conditions is emphasized and introduced, then the discrete scheme of this boundary conditions is deduced and applied to spectral element methods for wave equation.

本文从Chebyshev多项式逼近理论出发，详细介绍了谱元方法求解偏微分方程的过程；推导了流体中的声波动方程并在空间上对其进行了谱元离散；详细讨论了两种时间积分方法──中心差分法和Newmark方法，分析了它们的稳定性条件，并从理论上对比了两种方法的优缺点和适用范围；将吸收边界条件推广应用于谱元方法求解气动声学问题中，重点介绍了Clayton-Engquist-Majda吸收边界条件的原理和公式，推导了该吸收边界条件的变分形式，并将其引入波动方程的离散形式中。

I was in the school choir until my vice broke.

在我变声之前我一直在学校的合唱队。

This exhibit displays the inner structure of a cinematograph, the working principle of a motion-picture camera, mechanism for time-lapse photography, sound reproduction of an optical track-changing sound track, and a comparison of film and TV signal definition.

展示了放影机的内部构造，间歇抓片机构工作原理，视觉暂留机理，变积式光学声迹声音还原，比较电影与电视的清晰程度。

The following are the expressions for the mean pressure set up at the detection plate and for the time of the signal to progagate from the radiator to the detector:这里是1个公式,省略） where Re is the real part of the expression appearing within the braces, 0 is the density of the medium, vo is the amplitude of the vibrational velocity, c is the speed of sound in the medium, d2 = I +(r/zcos 8, z is the distance between the emitting and receiving plates, B is the angle between the axis of the acoustic channel and the axis of the tube, r = vro/c, v is the flow speed of the fluid, d is the diameter of the pipe, m is the circular frequency, k is the wave number, where a is the radius of the plate (this is taken as the same for the emitting and receiving plates for simplicity, but there is no difficulty in discussing plates differ~mg in radii),,~ is the vibrational frequency of the emitting plate, and The triple sums in the expressions for N~ and N2 may be neglected if the flow speed is low, since the contributions for these become negligible.

以下的表情为代表的压力设置在检测板甲，手持骑枪和时间的信号 progagate从散热器排出到检测器(这里是1个公式、省略)。在什么地方才是真正的出现在背带，表现为0密度的吗当时的媒介的振幅振动速度、c是声音的速度中、d2 =我+ r / z，8、z是距离的发射和接收板、B之间的角度对声信道和轴轴管，r = vro / c，v的流体的流动速率公式，d 管直径的圆频率，m，凯西是波数公式* n，一个是半径的板(这是作为相同的发射和接收吗为了简单，但板板是毫无困难地讨论不同半径)、镁-，~的振动频率的发光，。总结了三倍的表达方式和N2 ~能忽略的流量速度低，因为这些变得微不足道的贡献。

The following are the expressionsfor the mean pressure set up at the detection plate and for the time of the signal toprogagate from the radiator to the detector:这里是1个公式,省略） where Re is the real part of the expression appearing within the braces, 0 is the density ofthe medium, vo is the amplitude of the vibrational velocity, c is the speed of sound in themedium, d2 = I +(r/zcos 8, z is the distance between the emitting and receiving plates, B is the angle between the axis of the acoustic channel andthe axis of the tube, r = vro/c, v is the flow speed of the fluid, d is thediameter of the pipe, m is the circular frequency, k is the wave number,where a is the radius of the plate (this is taken as the same for the emitting and receivingplates for simplicity, but there is no difficulty in discussing plates differ~mg in radii),,~ is the vibrational frequency of the emitting plate, andThe triple sums in the expressions for N~ and N2 may be neglected if the flow speed islow, since the contributions for these become negligible.

以下是表达式平均压力为定于检测板和为信号时间progagate从散热器到探测器：（这里是1个公式，省略）假如再是出现在大括号表达式的实部，0是密度中期，沃是速度的振动幅度，C是健全的速度中，D2中=我+的导向8，z是对之间的距离发射与接收板，B是声之间的通道轴角该管的轴，R =中心内大多分为/荤，v是流体的流动速度，，D是管道直径，m是圆频率，k是波数，的其中一盘是半径（这是为重点，同样的发射与接收为le简单板，但没有讨论板的困难，在半径不同毫克），，是发光板振动频率，和在N的表达式的三重总结和N2可以忽略，如果流速低，因为这些变得微不足道的贡献。

The anterior two third of glottis, mucosa over the posterior commissure and the arytenoids muscle all remain intact.

故手术后除了呼吸阻塞的情况能够得到相当理想的改善之外，音声也没明显变坏的情形，亦无误呛或其他并发症的发生。

With showing the design and constant integration of multimedia technology, form and means of the exhibition become rich and varied day by day, the exhibition industry is weeding out the old and bringing forth the new constantly, has already differentiated the material object exhibition and fictitious exhibition out at present, most exhibitions use many kinds of multimedia technology such as falling-rising tone, light, electricity, demonstrate the stereoscopic, plural, interdynamic situation.

随着展示设计和多媒体技术的不断融合，展览的形式和手段也日益变得丰富多样起来，展览业不断推陈出新，目前就已经分化出实物展和虚拟展，大部分展览都用上了声、光、电等多种多媒体技术，呈现出立体的、多元的、互动的态势。

It is suggested that the change of cooling curve is due to the facs that:(1) the ...

所有这些是由于超声波在金属中传播时，声能变热能和使欲凝固分子做平行于結晶面振动的結果。

Unfortunately, a good skills too early, but from now on will look at the skills丐帮only ranked fourth, and other door-to-door now had their own strong indeed significantly weaker, the beggar is a pseudo-control door-to-door, with hidden weapon dabbler still, it is estimated that Pa has seen a knife, he switched to the door, and prices are not good short-term, medium-difficult, and the latter may be the rise of - Oh, sigh.

丐帮：停牌。45技能不错可惜出得太早了，不过从现在来看丐帮的技能也就只能排第四，其他门派如今变强了自己确实显弱了，乞丐是个伪控制门派，有了暗器也还是半吊子，估计霸刀也看出端倪，改投他门了，短期行情不妙，中期难做，后期可能会崛起--唉，一声叹息。

Voice and violin's sound are expressed in a reasonable and stiff way and are stinging with a DISCMAN.

如果用一般的晶体管耳放推动，稍有差池，声音就会变得比较"干"和"燥"，人声和提琴的感情表达得比较理性和呆板；如果用DICSMAN来听更是数码声四溢，难以入耳。

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。