查询词典 attenuation factor

Objective: Attenuation correction is one of the most important corrections in the quantification of positron emission tomography.

目的：在正子断层扫描之定量分析中，衰减修正为最重要的修正之一。

The error is mainly the system error of the experiment, and the velocity measurement error is the identification of the first arrival of the primary wave and the attenuation measurement is the coupling between the sample and transducer.

对误差分析表明，本文研究中的误差主要来自于实验系统误差，其中速度观测误差来自于对首波初至点的确定，声衰减观测的误差来源于探头与样品之间的耦合状况。

Under the condition of not considering the local topology effect and using a simplified layer velocity structure , we obtain the following results:(1) For a vertical strike-slip fault, the stations located on the parallel side of the slip , the transvers component ground motions show faster attenuation than the radial component motions.

对垂直走向滑移断层而言，沿著与断层面走向平行分布的测站，其与断层面走向平行分量的峰值，和其他二分量相较之下，有较明显的衰减趋势；而沿著与断层面走向垂直分布的测站，其与断层面走向垂直分量的峰值，和其他二分量相较之下，有较明显的衰减趋势。

in this paper,the stealthy target′s millimeter wave radiation character is studied.the millimeter wave attenuation induced by sea fog is analyzed.and the detecting capability of the ground-based passive millimeter wave radiometry arrays is discussed.according to one dimension 32 channel 8 mm radiometry arrays detecting stealth target,we have a simulation.the results of the simulation show that it is an efficient way in the thick sea fog condition.

摘 要：研究了空中隐身目标的毫米波辐射特性，分析了浓海雾对毫米波辐射信号的衰减，并对无源毫米波辐射计阵列探测热辐射源的性能进行了分析。在理论建模的基础上针对一维32通道8 mm辐射计阵列探测空中隐身目标进行了仿真实验，结果表明毫米波辐射计阵列在浓海雾气候条件下探测空中隐身目标是一种非常有效的手段。

The pressure attenuation of stress wave and the effect of blasting load on ground concrete structure in soil and rock blasting were investigated using LS_DYNA procedure in the aspect of mechanical properties of soil and rock, location of the goal and the explosives, as well as the rarefaction waves of air etc.

利用LS_DYNA程序，从岩土本身的力学性能、目标与炸药的位置、空气稀疏波的影响等多个角度出发，研究了岩土爆破中应力波的压力衰减以及爆破对地表混凝土结构物的影响，得到了其中的规律，为建筑结构的防护提供了一些思路与依据。

Such a phenomenon is another reason to read and write the first laser power attenuation caused by the phenomenon, if you use the same brand of disc recording, in the former period of time are normal, they are likely to decay with the power of the read-write head can be sent to the relevant maintenance companies.

出现此种现象的另外一个原因就是激光读写头功率衰减现象造成的，如果使用相同品牌的盘片刻录，在前一段时间内均正常，则很可能与读写头功率衰减有关，可以送有关厂商维修。

As an often used physical model with good theoretical and practical values, StreeterPhelps model has been widely used to study water quality. However, in some special water areas the utilitization of StreeterPhelps model has some limitation as confirming reaeration coefficient often comes from tests in rivers with fast water flow speed with no consideration of wave effects. Furthermore, in practical research in Three Gorges Reservoir, the changing rule of COD appears abnormally. In some water areas far from pollution source, the value of COD changes with time, but does not follow the exponential attenuation rule. This phenomenon can not be explained by former modified StreeterPhelps model.

StreeterPhelps模型是目前进行河流水质研究常用的物理模型，具有良好的理论和实用价值，然而在某些特定水域，该模型的应用受到限制，主要原因是复氧系数的取定多在水流速度较大情况下得到的，而未考虑水面波动对复氧系数的影响，另外，在实际研究过程中发现三峡库区COD变化的规律出现异常：在离排污口相当远的水域，COD随时间变化趋势并不是指数衰减，而是在某个常值附近微小摆动，以往很多修正过的StreeterPhelps模型都无法解释这个现象。

However, in some special water areas the utilitization of StreeterPhelps model has some limitation as confirming reaeration coefficient often comes from tests in rivers with fast water flow speed with no consideration of wave effects. Furthermore, in practical research in Three Gorges Reservoir, the changing rule of COD appears abnormally. In some water areas far from pollution source, the value of COD changes with time, but does not follow the exponential attenuation rule. This phenomenon can not be explained by former modified StreeterPhelps model.

StreeterPhelps模型是目前进行河流水质研究常用的物理模型，具有良好的理论和实用价值，然而在某些特定水域，该模型的应用受到限制，主要原因是复氧系数的取定多在水流速度较大情况下得到的，而未考虑水面波动对复氧系数的影响，另外，在实际研究过程中发现三峡库区COD变化的规律出现异常：在离排污口相当远的水域，COD随时间变化趋势并不是指数衰减，而是在某个常值附近微小摆动，以往很多修正过的StreeterPhelps模型都无法解释这个现象。

The break of symmetry caused by attenuation is studied, and the realizability condition of lossy network is discussed.

研究了损耗引起的对称破缺，并讨论了有耗网络可实现条件。

Anti-reflection lens coating called the film, the main role is to reduce the reflective glass surface to reduce light attenuation.

镜头的镀膜叫做增透膜，主要的作用是降低玻璃表面的反光，减少光衰减。

Pradeep Indulkar, a senior official at the Maharashtra state Home Ministry say 101 human were killed and 287 injured.

马哈拉施特拉邦内政部高级官员Pradeep Indulkar称，有101人在冲突中丧生，287人受伤。

Mark Frei, a senior vice president of West, says 80% of West's homeagents have some college education, compared with 30% of those whowork in office-based call centers.

Frei说，该公司80%在家办公的人员都拥有本科学位，而在公司电话中心工作的人中只有30%拥有本科学位。