[物] 衰減系數
Attenuation Coefficient The rate at which average power decreases with distance.
衰減系數平均功率隨距離的延長而降低的比率。
Calculating formulas and the table of attenuation coefficient of vibrating acceleration in slip form concrete slab are given.
給出了滑模混凝土闆中振動密實加速度衰減系數的計算公式和取值表格。
The attenuation coefficient of vibrating acceleration is related with the distribution of vibrating acceleration field in slip form paving concrete.
振動密實加速度衰減系數的大小關系到滑模攤鋪混凝土中振動加速度場的分布。
In this paper, the principle and primary results of measure ultrasonic sound velocity and attenuation coefficient by ultrasonic syntonic method are introduced.
本文介紹利用超聲共振法測量聲速和聲衰減系數的原理及自來水和乙醇的測量結果。
Meanwhile, the existence of the acoustic attenuation coefficient benefits the axial resolution.
同時，聲衰減系數的存在有利于軸向分辨率的提高。
The attenuation coefficient decreases with increasing of frequency and the gas density.
衰減系數隨頻率增加而減小，并且隨密度增加而減小。
The change of the attenuation coefficient with time possesses a relaxation character.
衰減系數隨時間變化，具有弛豫過程的特點。
A new measurement of attenuation coefficient is stu***d in this paper which was based on the backscattering lidar equation.
提出了一種基于後向散射式激光雷達方程的海水衰減系數現場快速測量方法。
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減系數值，不僅對WLAN的固定無線接入，而且對移動通信都具有參考價值。
Expound the component, the principle and the working process of the material attenuation measure device, give the attenuation coefficient calculation method.
闡述了材料衰減測試系統的組成、原理及工作過程，給出了衰減系數的計算方法。
Attenuation coefficient and velocity of ultrasonic are got in human body tissue.
得到了超聲波在組織中的衰減系數及聲速值。
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.
應用振動波傳播理論引出加速度衰減系數的概念，并對加速度衰減系數的試驗結果進行了分析。
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.
本文提供了一種用于識别這類隨機信號的數學統計模型，并介紹了一種時間平均法用來獲取超聲背散射信號的衰減系數。
The attenuation coefficient shows approximately linear behaviour with frequency over the frequency range used, and the attenuation slope increases with the void content.
結果表明：超聲衰減系數與頻率之間存線上性關系，而且其斜率隨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.
其中為單次散射近似時的衰減系數，表示激光每經過單位距離的介質後衰減率。
Increase of total suspended matter results in decrease of transparency and increase of beam attenuation coefficient.
懸浮物濃度的增加是引起湖水透明度降低和光學衰減系數增大的主要原因。
A function of the diffusion coefficient and attenuation coefficient was derived from the measured diffuse reflectance.
又從測得的漫反射率推得漫射系數和衰減系數的函數。
Single wavelength collimation transmittance experiment is designed and conducted, with total effective attenuation coefficient of tissue phantoms being obtained.
設計單波長準直光透射實驗并通過實驗測量組織模拟樣品的總衰減系數；
As a result a marked increase in beam attenuation coefficient occurred, simultaneously with the increase of pigment concentration.
由于浮遊植物大量繁殖，光束衰減系數隨葉綠素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.
單純的PEG400僅對去角質皮膚有一定的光透明效果，并且所導緻的皮膚衰減系數的降低僅為混合液作用後的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，管道衰減系數隨着氣流流速的增加，管壁吸聲系數的減小、管道截面幾何尺寸的增加而減小。
By using the digital means, the attenuation coefficient of the ultrasonic signal is measured, through which the sediment content can be obtained.
采用數字手段測取了超聲波信號的衰減系數，通過衰減系數可得出含沙量。
The effect of the acoustic attenuation coefficient of the media on the actual axial resolution have also been discussed.
文中還分析了介質的聲衰減系數對實際軸向分辨率的影響。
Preliminary investigations are made together with site attenuation coefficient, transformation of explosive ene.
同時結合場地衰減系數、炸藥能量轉換和減震效應等作了初步探讨。
In this paper, a method of extracting the group-averaged modal attenuation coefficient from the Modal-Vertical-Beam (MVB) analysis is discussed.
本文讨論了從模垂直波束（MVB）分析中提取分組平均模衰減系數的方法。
The acoustic parameters include complex reflection and transmission coefficient (echo reduction and insertion loss), attenuation coefficient, complex acoustic impedance and sound speed.
測量參數包括複反射系數（口聲降低）、複透射系數（插入損失）、衰減系數、複聲阻抗和縱波聲速。
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.
海底表層沉積物聲速和聲衰減系數的測量方法主要有兩種：取樣測量和原位測量。
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.
估算得到的紫外輻射衰減系數與DOC濃度均存在顯著性正相關，但UV-B波段要高于UV-A波段。
|attenuation quotient/damping coefficient;[物]衰減系數
衰減系數（Attenuation Coefficient） 是描述波（如電磁波、聲波）或粒子流在穿過介質時能量強度減弱程度的物理參數。它量化了單位距離内波或粒子束的強度衰減率，是通信、醫學影像、材料科學等領域的關鍵指标。
數學表達
衰減系數（通常記為 $alpha$）定義為介質中波強隨傳播距離的指數衰減率。若初始強度為 $I_0$，傳播距離 $d$ 後的強度 $I$ 滿足：
$$ I = I_0 e^{-alpha d} $$ 其中 $alpha$ 的單位為 $text{m}^{-1}$（每米）或 $text{dB/m}$（分貝每米）。該公式表明，$alpha$ 值越大，介質對能量的吸收或散射作用越強。
物理機制
衰減源于介質的吸收（能量轉化為熱能）和散射（傳播方向改變）。例如：
通信工程
光纖通信中，衰減系數決定信號傳輸距離。标準石英光纖在1550 nm波段的典型值為 0.2 dB/km，即每公裡信號損耗約4.5%。
醫學影像
在超聲診斷中，生物組織的衰減系數（如肝髒約 0.5 dB/cm/MHz）影響成像深度與分辨率。高頻超聲衰減更快，限制其穿透能力。
環境科學
大氣衰減系數用于評估污染物（如氣溶膠）對電磁波（如激光雷達信號）的削弱作用，助力環境監測。
權威參考來源：
- 光纖衰減機制 - Fiber Optic Communications Fundamentals (IEEE Press)
- 醫學超聲物理 - Journal of Ultrasound in Medicine, Vol. 38, pp. 112-129
- 大氣傳輸模型 - International Standard ISO 9613-1: Acoustics
Attenuation coefficient（衰減系數）是描述波或粒子在介質中傳播時強度衰減程度的物理量。以下是詳細解釋：
Attenuation coefficient表示單位路徑長度内能量或強度的衰減率。其數學表達式為： $$ I = I_0 e^{-mu x} $$ 其中：
如需更全面的定義或不同學科的具體應用，可參考相關物理或工程學文獻。
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