查询词典 attenuation constant

The experimental results show that:(1) for ideal spheres, the attenuation coefficient of velocity is constant, the air drag coefficient is slightly affected by the initial velocity and is a linear function of initial velocity, and (2) for real fragments formed by a warhead, the flight performances are different from ideal spheres, the air drag coefficient is affected by the flight velocity and is a linear function of flight velocity.

实验结果表明：(1)对于理想球形钨合金破片，在同一初始速度条件下，衰减系数为常数，空气阻力系数与初始速度有关，两者成线性关系；(2)对于经历爆轰驱动的球形钨合金破片，由于有轻微的质量损失和变形，速度衰减规律与理想球形钨合金破片有明显的区别，空气阻力系数与飞行速度有关，两者成线性关系。

Simulation results show that, for the fixed sampling frequency, the error rises with the frequency increasing of periodic signal, and decreases with the attenuation time constant increasing of non-periodic signal. The sampling frequency determines the upper limit of appropriate frequency band directly. The research provides the basis for the selection of cutoff frequency in filter design.

仿真结果表明，在采样频率确定时，对于周期信号，计算误差随频率的增加而增大，而对于非周期信号，计算误差随衰减时间常数的增大而减小，采样频率大小决定了插值法用于分布参数模型的适用频带上限，该研究为滤波器设计中截止频率的选择提供了依据。

Based on the existence of the solution to a LMI, a sufficient condition is obtained under which the composite systems can be quadratically stabilized with a H〓 norm bound constant on disturbance attenuation for all admissible uncertainties and a necessary and sufficient condition is obtained using BMI.

采用线性矩阵不等式方法，给出了系统可鲁棒H〓分散镇定的充分条件；采用双线性矩阵不等式方法，给出了系统可鲁棒H〓动态输出反馈分散镇定的充要条件，并给出了算法。

The retardation coefficients are 2.22 and 1.74 of silt medium and sand medium respectively. According to first-order reaction, s total natural attenuation rates constant are 0.0635/h and 0.0059/h respective of silt medium and sand medium.

根据一级动力学方程计算得出，硝基苯在淤泥介质中的自然衰减总速率常数为0.0635/h，在砂砾介质中的自然衰减总速率常数为

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。

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。

The result indicated:Without considering the influence of atmospheric turbulence,the visibility is higher,the beam intensity attenuation is smaller;Under the condition that only considered the atmospheric turbulence influence,wave length of transmission laser and refractive index of atmospheric structure constant have an important influence on beam intensity distribution.

结果表明：在不考虑大气湍流影响的条件下，能见度越高，光强衰减越小；在只考虑大气湍流影响的条件下，传输激光的波长，大气折射率结构常数，对激光远场光强分布具有重要影响。

In our thesis, contents are organized as following In Chapter 1 we present our topic's internal and overseas research situations, theoretical and practical significance, and introduce the research object and contents, and the main contributions of this dissertation. Chapter 2 reviews the development of the stability results for nonlinear systems and some relevant recent results, which include Lyapunov and LaSalle-Yoshizawa theorems for nonlinear systems, and stochastic edition for stochastic nonlinear systems. Sontag's formula for systems affine in control is presented in the frame of CLF. The concepts of disturbance attenuation and the inverse optimality are also explained in this Chapter. In chapter 3 we present the solvable theorem of inverse optimal gain assignment problem, design the inverse optimal controller and the inverse optimal tracking controller for strict-feedback nonlinear continuous systems with unknown time-varing bounded disturbances and constant unknown parameters using an adaptive backstepping algorithm, which are nonlinear, continuous and are easier to realize. These designs are fully systematic and the algorithm can be directly coded in symbolic software. The results of simulation show the effectiveness of the control algorithms.

论文的结构如下：在第1章中，给出了本文研究课题的研究现状、理论意义和实际应用，并介绍了本文的研究对象、研究内容以及主要贡献；在第2章中，针对确定性非线性系统和随机非线性系统，分别介绍了Lyapunov定理、LaSalle-Yoshizawa定理及其随机版本；对仿射系统，在控制Lyapunov函数框架下，给出了Sontag公式；同时给出了非线性系统扰动抑制和逆最优控制问题的基本概念；在第3章中，针对具有未知时变有界扰动和未知定常参数的一类不确定非线性系统，给出并证明了逆最优增益配置可解定理，使用自适应Backstepping算法和均值定理，系统地设计了自适应逆最优控制器和逆最优跟踪器，这种设计方法可同时获得逆最优控制策略和自适应律，简单明了，仿真结果表明该控制算法的有效性，并给出了性能估计。

He and Nina moved to California and lived at 2005 Ivar Street, Apt.

他和Nina搬到加州，并在2005年伊瓦尔街，公寓生活。

Droperidol （ potently inhibits transfected HERGchannels and this is the probable mechanism for QT prolongation.

氟哌利多有效地抑制了转染的 HERG 钾通道，可能是 QT 间期延长的机制。