查询词典 attenuation

In this paper, the dynamic behaviours of polymer-cement composite material are investigated, including the dynamic rigidity, internal frication and ratio of elastic energy to unelastic energy in hysteresis loop under vibration, the stress wave propagation and attenuation in this material, the impact toughness and abrasiveness.

本文研究了聚合物水泥复合材料的动力性能，其中包括动力刚度、振动状态下的内耗及振动滞后曲线中的弹性与非弹性应变能之比、应力波的传播与衰耗、冲击韧性和耐磨硬度等。

Testing and investigation of Sound Absorption Coefficient and Sound Attenuation show sound-absorbing wool materials have excellent sound absorption properties.

通过对羊毛吸声材料的吸声系数与声衰减能力的测试，发现其吸声性能优良。

In conventional seismic data processing, the earth is regarded as prefectly elastic medium.However,the pores of stratum rock often contain fluid. So, when the seismic wave propagates in it, there are energy attenuation and phase distortion related to frequency. Moreover, the attenuation, scattering,and dispersion of high-frequency components are far higher than that of low-frequency components.

常规地震资料处理中把大地看成是完全弹性介质，实际上，地层岩石孔隙中常常含有流体，当地震波在其中传播时要发生与频率相关的能量衰减和相位畸变，且高频成分的衰减、散射和弥散远高于低频成分。

Results:11 cases of angiomyolipoma manifested as a solitary renal mass on unenhanced ct, 6 cases of masses appeared as homogeneous attenuation, while 5 cases of tumors as heterogeneous attenuation.

对11例手术病理证实的乏脂肪aml的螺旋ct及临床表现进行回顾分析。结果：11例均为单发肿块，平扫表现密度均匀者6例，不均匀者5例。

Attenuation The trp operon is also controlled by attenuation A leader sequence in the polycistronic mRNA upsteam of the coding region of the trpE structural gene encodes a 14 amino acid leader peptide including two tryptophan residues The RNA leader sequence can for several possible stem-loop secondary structures,one of which can act as a transcription terminator whilst a different stem-loop can act as an anti-terminator.

弱化作用 trp 操纵子也受到弱化作用的调控。在trpE结构基因编码区上游的多顺反子mRAN上有一段前导序列，可以编码一个含有14个氨基酸的前导肽，此肽中含有两个色氨酸残基。

HRCT scan showed peripheral area of ground-glass attenuation adjacent to subpleural honeycombing in one patient,and diffusely distributed ground-glass opacity in another patient.Two patients had received cortieosteroid treatment.For one patient, the symptoms improved, and ground-glass attenuation adjacent to subpleural honeycombing had almostly resolved.The other patient died of respiratory failure.

其中1例患者的双肺新出现的磨玻璃影，沿胸膜下蜂窝肺外周分布；另1例患者HRCT表现为新出现的磨玻璃影呈弥漫性分布。2例患者均接受激素治疗。1例患者气紧、咳嗽症状明显缓解，胸部HRCT的磨玻璃样影基本吸收；另1例患者死于呼吸衰竭。

Periodic fluid pulsation in aeroplane hydraulic piping could induce fluid-construction vibration and lead to fatigue damage. It is impossible to find the error sensor's optimization location because of the pressure standing wave, and the pulsation attenuation effect is not perfect when adopting pulsation attenuation at single point. For this reason, a distributed active control method of fluid pulsation was presented. To avoid stationary point in all aviation states, several fluid pulsation actuators and error pressure sensors were placed along the piping. The second fluid pulsation produced by actuators can counteract the primary pulsation brought by aviation piston pump and make the mean pulsation of whole piping minimum when adopting adaptive feed- forward control and the filtered-X least mean square algorithm.

针对飞机液压能源管路系统中的周期性流体脉动诱发流固耦合振动，导致管路疲劳损伤的问题，针对管路中存在压力驻波特性，在采用单点消振时寻找误差传感器最佳布局位置困难而引起脉动抑制效果不理想的缺点，提出了一种分布式流体脉动主动控制方法，即沿管路不同位置布置多个主动消振阀和误差压力传感器，在任意飞行阶段，避开压力驻波点，以误差压力传感器的脉动测量值为控制目标，采用一种针对周期脉动主动控制的自适应前馈控制法和多通道自适应滤波－X LMS算法，调整控制器参数，使主动消振器产生的次级脉动与管路中的初始脉动相互抵消，达到整个管路中的平均流体脉动最小的效果。

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。

Based on regression analysis between PAR attenuation coefficients, euphotic depths, secci disc and main light attenuators, phytoplankton and organic suspended solid play a main role in regulating the attenuation of light.

对PAR衰减系数、真光层深度、透明度等表观光学参数与主要水色因子进行相关分析发现，水体中浮游藻类和有机颗粒物对西湖水体光学性质影响最大。

The main factor that affects the resolution of seismic prospecting is Earth's absorption and attenuation effect on high frequency signals. Study and calculation of Earth's absorption and attenuation effect show that medium deep and deep reflectors over 135 Hz can not be recorded even by 24-bit seismometers.

地震勘探分辨率不高的主要原因是地层对地震波高频成分的吸收衰减，通过对地层吸收衰减深入的理论计算可知，既便使用 2 4位遥测地震仪，在中深层勘探中也无法记录主频超过 13 5Hz的地震波。

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。