查询词典 attenuation factor

A single chip controlled by digital detector based on the principle of microwave attenuation constant has been introduced. It has been shown that it can test moisture content of veneer on-line, with its nondestructive, far-reaching, color-proof and accurate features, and it can show the value of the moisture content.

该系统以计算机为核心，基于微波测量原理，能在线测量木材含水率，具有无损检测、测量范围宽、不受材料颜色的影响、测量误差小、输出显示木材含水率等特性。

Based on the characteristic equation of THz electromagnetic wave in metallic hollow waveguide, the dependence of the transformation attenuation and phase constant on the frequency of THz wave, inner radius of the waveguide and conductance of the metal material using Newton-Raphson iterative method.

从其传输的特性方程出发，利用Newton-Raphson迭代方法数值模拟了传输损耗和相位常数随太赫兹波频率、波导内径以及波导中金属镀层的电导率变化关系。

The results of numerical modeling indicate that the thin film microstrip lines with finite ground width have good broad band characteristics and the characteristic impedance, attenuation constant and effective dielectric constant have small change with the finite ground width changing.

作者用该程序对有限接地面薄膜微带线进行了时域仿真，结果显示在保证传输模不受干扰的情况下，在较宽频带范围内有限接地面对微带特性有微弱影响。

The rules of the cold-test characteristics changing with helix pitch are also studied and it turns out that, with increasing helix pitch, the phase velocity increases linearly, the interaction impedance changes nonlinearly and the attenuation constant decreases nonlinearly. At the same time, with the limitation of the synchronism between the electron beam and the electromagnetic wave, the change of pitch is small and therefore an approximate linear relation can be introduced.

研究表明：相速几乎随螺距增大而线性变大，互作用阻抗与螺距是非线性的关系，衰减常数随螺距增大而非线性地减小；由于在维持电子注与电磁波速度同步的限制下，螺距变化的幅度不可能很大，因此可近似按线性关系来处理互作用阻抗及衰减常数与螺距之间的关系。

A large uumber of numerical calculations using the analytic formula and the dispersion equation have been candied out on the relations of the attenuation and phase constant with wave frequency, thickness and conductivity of the lossy layer.

此式适用于截止频率附近，通过解析表达式和波导模式色散方程，对衰减常数和相位常数进行了大量数值计算，得到了它们随损耗层厚度、频率以及损耗层电导率的变化规律，两种方法所获得的结果有较好的一致性，研究表明，损耗强度和损耗层厚度的变化会改变波导中电磁模式的色散和简并特性，对于改善高功率回旋行波放大器中注波互作用带宽和模式竞争非常有益。

Applying LMI technique, quadratic stability theory, and H〓 control theory, three methods of robust stability analysis and robust controller design for uncertain fuzzy systems are proposed respectively. Among them, LMI based technique can analyze the uncertainties raised in the premises and in the consequent of fuzzy systems. The resulting stabilizing state feedback controllers have maximum stability margins for both kinds of uncertainties. Quadratic stability theory based approach can apply LMI technique and other methods to design fuzzy controllers. H〓 control theory based design can get H〓 controller with constant disturbance attenuation for each local subsystem. Using the given stability criterion of generalized systems, the robust stability of fuzzy systems can be checked.

其中，基于LMI的方法可分析由模糊系统的前件或后件引起的不确定性，得到的稳定的状态反馈控制器对这两类不确定性具有最大的稳定裕度；基于二次稳定理论的方法可应用LMI技术和其它方法设计模糊控制器；基于H〓控制理论的方法可得到各局部子系统具一定干扰抑制性能的鲁棒H〓控制器，而全局系统的鲁棒稳定性可应用所给出的稳定条件进行检验。

The small concrete blocks and big concrete plate were constructed for the experiment. The dielectric constant and the attenuation index obtained by the first 1 and 1/2 waveforms reflected from the concrete surface are used as the parameters.

研究使用1GHz天线，经由实验分析采用抬高天线与受测物距30cm方式检测混凝土，将测得混凝土反射波形计算出介电常数，并选择反射脉冲波形1又1/2振幅面积来做为量测标的，将火害前后振幅面积计算求得衰减常数，比较火害前后混凝土之差异性。

Noise attenuation of seismic data processing is one of the key questions that can not be ignored.

噪声衰减是地震资料处理中的关键问题之一。

Then, the influences of some parameters on phase speed and attenuation are analyzed.

给出了圆柱管的一些参数对相速度和衰减的影响。

A new method of precise measurement of optical fiber attenuation.

一种新的精确测试光纤衰减方法的探讨。

So it was last week in Selma , alabama.

上星期在亚拉巴马州塞尔马市发生的事件也是这样一个转折点。

The group also spearheads various social programs in China.

该组织还带头参与中国的各种社会活动。