[物] 衰减系数
Attenuation Coefficient The rate at which average power decreases with distance.
衰减系数平均功率随距离的延长而降低的比率。
Calculating formulas and the table of attenuation coefficient of vibrating acceleration in slip form concrete slab are given.
给出了滑模混凝土板中振动密实加速度衰减系数的计算公式和取值表格。
The attenuation coefficient of vibrating acceleration is related with the distribution of vibrating acceleration field in slip form paving concrete.
振动密实加速度衰减系数的大小关系到滑模摊铺混凝土中振动加速度场的分布。
In this paper, the principle and primary results of measure ultrasonic sound velocity and attenuation coefficient by ultrasonic syntonic method are introduced.
本文介绍利用超声共振法测量声速和声衰减系数的原理及自来水和乙醇的测量结果。
Meanwhile, the existence of the acoustic attenuation coefficient benefits the axial resolution.
同时，声衰减系数的存在有利于轴向分辨率的提高。
The attenuation coefficient decreases with increasing of frequency and the gas density.
衰减系数随频率增加而减小，并且随密度增加而减小。
The change of the attenuation coefficient with time possesses a relaxation character.
衰减系数随时间变化，具有弛豫过程的特点。
A new measurement of attenuation coefficient is stu***d in this paper which was based on the backscattering lidar equation.
提出了一种基于后向散射式激光雷达方程的海水衰减系数现场快速测量方法。
The research result and the rain attenuation coefficient thus obtained provide valuable reference not only in WLAN and immobile wireless accessibility but also in mobile communication.
研究得出的降雨衰耗和降雨衰减系数值，不仅对WLAN的固定无线接入，而且对移动通信都具有参考价值。
Expound the component, the principle and the working process of the material attenuation measure device, give the attenuation coefficient calculation method.
阐述了材料衰减测试系统的组成、原理及工作过程，给出了衰减系数的计算方法。
Attenuation coefficient and velocity of ultrasonic are got in human body tissue.
得到了超声波在组织中的衰减系数及声速值。
Using theory of vibration wave propagation, the concept of the attenuation coefficient of vibrating acceleration is drawn, and the test results of attenuation coefficient are analyzed.
应用振动波传播理论引出加速度衰减系数的概念，并对加速度衰减系数的试验结果进行了分析。
In this paper, a mathematical model is used to characterize this random signals, and a time averaging method is used for obtaining the ultrasonic attenuation coefficient.
本文提供了一种用于识别这类随机信号的数学统计模型，并介绍了一种时间平均法用来获取超声背散射信号的衰减系数。
The attenuation coefficient shows approximately linear behaviour with frequency over the frequency range used, and the attenuation slope increases with the void content.
结果表明：超声衰减系数与频率之间存在线性关系，而且其斜率随孔隙率的增大而增大。
Among which, is the attenuation coefficient at the single scattering approximation, representing the attenuation rate when the laser passes through medium in unit distance.
其中为单次散射近似时的衰减系数，表示激光每经过单位距离的介质后衰减率。
Increase of total suspended matter results in decrease of transparency and increase of beam attenuation coefficient.
悬浮物浓度的增加是引起湖水透明度降低和光学衰减系数增大的主要原因。
A function of the diffusion coefficient and attenuation coefficient was derived from the measured diffuse reflectance.
又从测得的漫反射率推得漫射系数和衰减系数的函数。
Single wavelength collimation transmittance experiment is designed and conducted, with total effective attenuation coefficient of tissue phantoms being obtained.
设计单波长准直光透射实验并通过实验测量组织模拟样品的总衰减系数；
As a result a marked increase in beam attenuation coefficient occurred, simultaneously with the increase of pigment concentration.
由于浮游植物大量繁殖，光束衰减系数随叶绿素a含量升高而增大。
Single PEG400 can only do some effect on the sample without SC, and the change in attenuation coefficient of samples is just 2/3 of that treated by mixed solution.
单纯的PEG400仅对去角质皮肤有一定的光透明效果，并且所导致的皮肤衰减系数的降低仅为混合液作用后的2/3。
The acoustic attenuation coefficient will decrease with the increase of flow velocity, or with the decrease of absorption coefficient of boundary, or with the increase of section area of the duct.
研究表明，管道衰减系数随着气流流速的增加，管壁吸声系数的减小、管道截面几何尺寸的增加而减小。
By using the digital means, the attenuation coefficient of the ultrasonic signal is measured, through which the sediment content can be obtained.
采用数字手段测取了超声波信号的衰减系数，通过衰减系数可得出含沙量。
The effect of the acoustic attenuation coefficient of the media on the actual axial resolution have also been discussed.
文中还分析了介质的声衰减系数对实际轴向分辨率的影响。
Preliminary investigations are made together with site attenuation coefficient, transformation of explosive ene.
同时结合场地衰减系数、炸药能量转换和减震效应等作了初步探讨。
In this paper, a method of extracting the group-averaged modal attenuation coefficient from the Modal-Vertical-Beam (MVB) analysis is discussed.
本文讨论了从模垂直波束（MVB）分析中提取分组平均模衰减系数的方法。
The acoustic parameters include complex reflection and transmission coefficient (echo reduction and insertion loss), attenuation coefficient, complex acoustic impedance and sound speed.
测量参数包括复反射系数（口声降低）、复透射系数（插入损失）、衰减系数、复声阻抗和纵波声速。
There are two methods for the measurement of acoustic speed and attenuation coefficient, the first is measure after sample; the other is in-situ measurement.
海底表层沉积物声速和声衰减系数的测量方法主要有两种：取样测量和原位测量。
The estimated ultraviolet radiation attenuation coefficient and DOC concentration all existed markedly positive relationship; but UV-B wave band was higher than UV-A wave band.
估算得到的紫外辐射衰减系数与DOC浓度均存在显著性正相关，但UV-B波段要高于UV-A波段。
|attenuation quotient/damping coefficient;[物]衰减系数
衰减系数（Attenuation Coefficient） 是描述波（如电磁波、声波）或粒子流在穿过介质时能量强度减弱程度的物理参数。它量化了单位距离内波或粒子束的强度衰减率，是通信、医学影像、材料科学等领域的关键指标。
数学表达
衰减系数（通常记为 $alpha$）定义为介质中波强随传播距离的指数衰减率。若初始强度为 $I_0$，传播距离 $d$ 后的强度 $I$ 满足：
$$ I = I_0 e^{-alpha d} $$ 其中 $alpha$ 的单位为 $text{m}^{-1}$（每米）或 $text{dB/m}$（分贝每米）。该公式表明，$alpha$ 值越大，介质对能量的吸收或散射作用越强。
物理机制
衰减源于介质的吸收（能量转化为热能）和散射（传播方向改变）。例如：
通信工程
光纤通信中，衰减系数决定信号传输距离。标准石英光纤在1550 nm波段的典型值为 0.2 dB/km，即每公里信号损耗约4.5%。
医学影像
在超声诊断中，生物组织的衰减系数（如肝脏约 0.5 dB/cm/MHz）影响成像深度与分辨率。高频超声衰减更快，限制其穿透能力。
环境科学
大气衰减系数用于评估污染物（如气溶胶）对电磁波（如激光雷达信号）的削弱作用，助力环境监测。
权威参考来源：
- 光纤衰减机制 - Fiber Optic Communications Fundamentals (IEEE Press)
- 医学超声物理 - Journal of Ultrasound in Medicine, Vol. 38, pp. 112-129
- 大气传输模型 - International Standard ISO 9613-1: Acoustics
Attenuation coefficient（衰减系数）是描述波或粒子在介质中传播时强度衰减程度的物理量。以下是详细解释：
Attenuation coefficient表示单位路径长度内能量或强度的衰减率。其数学表达式为： $$ I = I_0 e^{-mu x} $$ 其中：
如需更全面的定义或不同学科的具体应用，可参考相关物理或工程学文献。
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