查询词典 wave velocity

Methods: The motion of parasternal papillary muscle anterior wall, inferior wall, posterior wall, and lateral wall were detected by 2DE at short axis view of left ventricle before PTCA, 3 d and 1-3 months after PTCA in 33 cases of patients with coronary heart disease, who received PTCA+stent at selected time. Peak systolic velocity of subendocardial, subepicardial and middle layer myocardium, transmural velocity difference of the same segments and Outer lateral mitral valve annulus were also detected at apical 4 chamber view by pulsed wave tissue Doppler imaging.

对33例择期行PTCA+支架术的冠心病患者用HP5500型超声诊断仪，于PTCA术前及术后3d、1-3个月对胸骨旁左心室乳头肌短轴切面的前间壁、下壁、后壁、侧壁行二维超声心动图(2DE)检测各节段的室壁运动情况，用脉冲组织多普勒成像检测上述各节段的内、外膜下及中层心肌的收缩期峰值速度，内外膜下心肌的收缩速度差及心尖四腔观二尖瓣外侧环的收缩期峰值速度。

Methods The electromyography, motor nerve conduction velocity,F wave conduction velocity and somatosensory evoked potential were examined in 97 cases of cervical radicular spondylosis, and were compared with 50 normal persons.

对97例神经根型颈椎病患者进行肌电图、运动神经传导速度、F波传导速度和体感诱发电位检测，并与50名正常人组对比。

The calculation results shows that ,(1) when the rotor rotates at the working speed, a local regurgitant whirlpool that is rightabout to the rotor"s rotating direction appears in the classifying region, which makes the separated granules come back to the outside of the classification district and influences the classification efficiency of the turbine classifier;(2) in the condition of a low rotating speed of turbo rotor, ultrafine particles can follow the gas phase by and large, but when the rotating speed increases, a phenomenon of velocity slippage between two phases appears evidently;(3) A operating parameter, air flow rate is so important that can directly influence the stability of flow field in classifying chamber, the bigger the air flowrate is , the steadier the flow field is;(4) Compared with straight blades, the new shape of blades with backward crooked elbow are helpful to improve the stability of flow field and form whole stream easily, also beneficial to advance the classification accuracy and classification efficiency;(5) The motion trace of particles are very complicated when the turbo rotor rotates at a high speed, the constant bounce of the particles appear between the blades and the coarse particles are even bounce back from the inlet, only the finer can pass through the classification area from the oulet;(6) Along with the increase of the rotor"s rotating speed, radiah axial and tangential velocity all begain to fluctuate repetitively like sine-wave, the smaller the particles are, the more violently they fluctuates.

数值模拟结果表明，(1)在涡轮达到工作转速时，在分级区域形成了一个与涡轮旋转方向相反的局部回流涡，它使得分离出来的细粒重又被带回分级轮外边缘，从而严重影响分级机的分级效率；(2)粉尘粒子在涡轮低速运动情况下，基本上能跟随气体运动，但随着转速加大，两相之间出现了明显的速度滑移现象；(3)分级机工作时的风量也是一个比较重要的操作参数，它可以直接影响到分级机内腔流场的稳定性，风量越大，流场越稳定；(4)同直叶片形状相比较，带后弯导板的叶片，有利于改善流场的稳定性，流场容易形成整体流，对提高分级效率和分级精度都非常有利；(5)粒子轨迹线在涡轮转速较高时十分复杂，有的出现了反复的弹跳现象，大颗粒不能通过分级区域而从进口返流了，只有细小的颗粒才从出口处流出；(6)涡轮转速加大时，粒子的径向、轴向和切向速率出现了明显的类似于正弦波的脉动现象，颗粒越小，脉动程度越为剧烈。

In order to select optimal grid and good computation efficiency to recover the entire signal, aiming at the Ricker wavelet commonly used in forward modeling, we analyzed the alias and signal restoration problem in finite-difference method based on spatial sampling theorem and seismic wave traveling regulation in media with different velocity, to derive quantitative relationship among the modeling grid size, minimum velocity of model layer, and recovered main frequency of wavelet.

为了选择最佳的网格尺寸以及以最小的计算量完整地恢复出信号，针对地震波场正演模拟中经常使用的Ricker子波，根据空间采样定理和地震波在不同速度介质中的传播规律，分析了有限差分算法中的假频和信号恢复问题，推导出模拟网格尺寸、模型地层的最小速度和能够恢复的子波主频之间的近似定量关系，并用数值算例验证了这一关系。

Further, author introduces the concept of many kinds velocity and their inherent physical meaning, and then discusses the theory foundation and methods of migration velocity error analysis based on the acoustic wave equation.

进而，介绍了各种速度概念及其内在的物理涵义，讨论了基于波动方程的偏移速度误差分析理论基础及其方法原理。

Because the velocity of the ore bed in the fault trough is different with the velocity of the both sides layers, so for the sake of designing demand we should full use the action of calibrating lithologic character of the refraction wave.

由于在地堑内的矿层和两侧的地层速度不同，为了满足设计要求，在施工过程中，充分利用折射波视速度的岩性标定作用，也就是说根据折射波不同的视速度反映，可以准确判断地震测线是否已控制到地堑的边界断层，并及时调整反射波测线布置，大大缩短了现场处理时间，提高了勘探效率。

Based on the hydroelastic response theory, the motions of the VLFS are analyzed in the dissertation, and then the velocity potential of fluid and the velocity potential of deflection wave of VLFS are solved.

本文在水弹性响应理论的基础上对超大型浮体结构的运动进行了分析，并求解出流体的速度势和浮体挠曲波速度势。

In contrast,the SAW and PSAW have Δv/v effect.These datashow that the high velocity surface acoustic mode is the high velocity head wave.

这些充分证明了，压电晶体半空间中普遍存在的高速表面模式是我们所预期的高速头波。

Concrete components have flaws, such as loose, hole, slit band and so on. These flaws not only lead to the change of acoustic velocity, but also have strong absorption and attenuation action to the acoustic wave. It is an effective method to detect engineering quality of concrete components by using acoustic velocity CT and attenuation CT combined detection technology.

混凝土构件中存在的诸如松散、空洞、缝隙夹层等缺陷，不仅造成声波速度的变化，而且对声波具有较强的吸收衰减作用，利用声波速度CT和衰减CT联合检测技术是检测混凝土构件工程质量的有效方法。

In the paper, the velocity charactedstics of guided wave s along single interface and low-velocity lay-er in cross-hole seismic surveys are researched.

本文研究了井间地震勘探中单界面和低速层导波的速度特征。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。