查询词典 attenuation

Methods Ionization chamber and film dosimetry methods were used to compare the angular dose distribution, point source approximation in the area close to the source,the coincidence of inverse square law of source strength and the scatter and attenuation in water medium,of a cylindrical, miniature 192 Ir source and "the ideal point source".

用电离室法与胶片法实测国产192Ir放射源空间剂量角分布、点源的近似性与源强反平方定律的符合性以及水介质散射与衰减特性，并与点源剂量分布特性比较。

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。

The average electron density in the linear attenuation zone is about 10^-5 of neutral particle density, and can diffuse over a wide rarea, The conclusion will supply some valuable references to the research of electromagnetic wave and artificial plasma interaction, the plasma invisibleness research of missile and special aerocraft,and the design of artificial plasma source.

平缓衰减区中的平均电子密度约为中性分子密度的十万分之一。并且可以覆盖较大范围。这些结果对于电磁波与人工等离子体相互作用的研究、导弹和空间飞行器的等离子体隐身研究及人工等离子体发生器的设计有一定的参考价值。

The characteristic of the attenuation when high-power microwave propagates through the lower ionosphere is analyzed in this paper.

主要研究高功率微波在低电离层的传输衰减特性。

The methods for controlling transformer noise are introduced: for noise source control,using high-quality silicon-steel sheet,and adopting effective measures in transformer design,techniques and installation;for noise propagation control,adopting muffler device,sound insulation board and isolation booth,etc.to enhance noise attenuation.

详细介绍了变压器的噪声控制方法，在噪声源控制上选用优质高取向硅钢片，在设计、工艺和安装等诸多方面采取有效措施降低噪声；在噪声传播过程中采用缓冲装置、消声法、设置隔音层、隔音室等方法增大噪声在传播过程中的衰减以降低噪声。

The formula of seismic intensity attenuation fitted by using 37 isoseismal lines of 14 earthquakes in Shandong and near area.

一、前 -j-J 目地震烈度衰减方程是工程地震危险性分析中的不可缺少的主要参数之一。

Based on the latest intensity data of North China that include 48 earthquakes and 139 isoseismal lines, the attenuation relationship of seismic intensity is obtained.

除了(1)式之外，有的研究者还采用了如下形式的经验公式：I=A+BM-ln(R+R0)+ε(2)由于地震烈度衰减规律是通过对烈度数据进行统计回归而得到的，而使用衰减关系式进行的直接回归会存在种种不足，因此，前人根据地震烈度衰减的特点提出了不同的统计模型和方法。

Methods: The PP/porous PTFE/PP composite electret film was prepared with porous PTFE,polyethylene and PP by heat melting technique.The charge storage stability of the electret film and transportation were evaluated by using the methods of isothermal surface potential attenuation and open-circuit thermally stimulated discharge current spectra.

利用热融法将多孔PTFE、聚乙烯和PP制备成PP/多孔PTFE/PP复合膜驻极体，利用等效表面电位衰减和开路热刺激放电电流谱方法研究PP/多孔PTFE/PP驻极体的电荷储存稳定性及其输运规律。

Methods: The PP/porous PTFE/PP composite electret film was prepared with porous PTF'E, polyethylene and PP by heat melting technique. The charge storage stability of the electret film and transportation were evaluated by using the methods of isothermal surface potential attenuation and open-circuit thermally stimulated discharge current spectra.

利用热融法将多孔FTFE、聚乙烯和PP制备成PP/多孔PTFE/PP复合膜驻极体，利用等效表面电位衰减和开路热刺激放电电流谱方法研究PP/多孔PTFE/PP驻极体的电荷储存稳定性及其输运规律。

Then formaldehyde attenuation curve which purification products reduce 5~10 times formaldehyde were tested, which has been tested at 1 m^3 environment deck according to experiment condition of eliminator standard GB/T18801-2002. Moreover, purification quantity per hour was computed by mathematics line integral surface. Results: The purification quantity which formaldehyde has been purificated by kieselguhr material was 1.44 mg/m^2h.

本研究选用了硅藻土和光催化两种原理空气净化材料，以室内空气常见的污染物甲醛为目标，参照国家空气净化器标准(GB/T18801-2002)中的实验条件，在1立方公尺环境测试舱内分别发生室内空气质量标准10倍的甲醛气体，测试净化产品对甲醛衰减曲线，运用数学曲线积分面积的计算模式来计算单位时间净化量。

Connectors are lines that can be anchored to particular places, called glue points , on the graphic object.

连接符，可固定在图形对象的特定的地方的线条。

Another way of putting it, too many agents have a say in each other's work, and bureaucratic rigor mortis sets in.

另一种表达是，太多的作用物在彼此的工作里都有话语权，官僚的僵尸开始抬头。