查询词典 attenuation

Regions of lowest x-ray attenuation and high MR signal represent high water content in edematous non-hemorrhagic brain.

这在旋转－反射成像的图像中是最清楚的，但在T2加权GE像中也能观察到。

In this paper, the origin, propagation and attenuation of environmental vibration is studied by both test and theory method, so that we can evaluate and forecast the environmental vibration produced by elevated railroad traffic according to practice.

本文就高架轨道交通引起环境振动的发生机理及振动的传播和衰减规律进行实测及理论分析研究，以便对高架轨道交通引起环境振动进行切合实际的评价和预测。

The concept of attenuation ellipsoid is proposed.

提出了衰减椭球概念。

Further generalization gives out the concept of generalized attenuation ellipsoid and its application.

进一步推广，给出了广义衰减椭球概念及其应用。

Chapter 2 proposes the concept of attenuation ellipsoid.

在第2章首先利用散射参数提出衰减椭球的概念，并讨论其性质。

The exponential attenuation curve of the gain along the pulse propagation time is simulated.

分析了分幅相机增益衰减的理论模型，利用Mathematica软件模拟了增益随电脉冲传输时间指数衰减的曲线图。

The experimental results show that He-Ne laser penetration of tissues obeys the law of exponential attenuation.

实验证明He—Ne激光穿透组织是遵循指数衰减的规律。

From experimental and calculated results, X-ray transport attenuation changes in exponential function, and scaling law for radiation transport is obatined.

由实验和计算的结果推断X光在管靶中输运是指数衰减的，由数值计算结合实验结果得到辐射输运的定标公式。

Based on a series of signal process and noise source identification techniques, especially the major noise source identification methods, such as expurgation method, sound intensity analysis, spectrum analysis vibro-acoustic correlation analysis and so on, the pass-by noise control of SC7080A and SC6360B are studied in detail. By the roadway and dais experiments, the major noise and radiating parts are identified and some economical controlling methods are made. For the SC7080A, to control the emissing noise from the intake and shell vibration of air cleaner, a intake muffler is installed between the air cleaner and intake valve. Based on the theory of Helmholtz resonator, One three-parallel-connected resonant silencer is designed and trial-manufactured. For the SC6360B, the attenuation performance of exhaust muffler in high frequency region is improved. To reduce the vibration noise of shell part, the structure of oil sump tank, exhaust manifold shield and exhaust manifold shield are analyzed and improved. At the same time, some measures, such as sound absorption, sound insulation, are taken to reduce the noise of engine surface emissivity and a sound shield is designed.

本文首先综述了目前国内外汽车加速噪声控制的现状、主要方法和技术措施，在此基础上，结合SC7080A和SC6350B汽车的车外加速噪声水平及现状，综合运用分别运行法、声强法、频谱分析法、声振相干函数法等现代噪声源识别方法，对SC7080A和SC6360B汽车进行了准确详细的车外加速噪声源识别并提出了经济可行的控制方案，针对SC7080A，主要在空气滤清器和进气阀门之间的进气管道上加装进气消声器，抑制空气滤清器壳体表面和进气口两处的噪声辐射，根据Helmholtz共振腔原理设计了三腔并联旁支型共振消声器，并进行了工程化设计和试制；针对SC6360B，主要改善了排气消声器在高频段的消声性能，对罩壳类零件进行了结构改进，降低了其表面噪声的辐射，并对发动机舱进行了吸声、隔声处理，设计了发动机隔声罩。

The Site Attenuation of an ideal OATS is the standard [FCC OST-55, 1977] to be followed by any practical OATS or test chamber. An ideal OATS is the half space above a perfect conducting ground plane that extended to infinity.

用来测试电子资讯类产品之电磁辐射强度，以作为判定是否符合法规限定之安全辐射强度上限，因此理想开放测试场地就是实际测试场地必需在容许误差内达成的标准。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。