dng

Thermodynamic study on the extraction of Au ( iii ) with DNG

DNG萃取金（Ⅲ）的热力学研究

The scatter characteristic of electrically large objects coated by DNG is analysed .

分析了覆盖双负介质电大尺寸目标的散射特性。

Numerical results show that DNG can reduce the backscattering of objects , but increase forward scattering of objects simultaneously .

数值结果表明，双负介质减小目标后向散射，同时增大了目标的前向散射。

The full-wave simulations of double negative ( DNG ) medium are made using higher-order time-domain computational electromagnetic methods .

利用高阶时域电磁计算方法对双负媒质的电磁特性进行了全波仿真。

The design method and electromagnetic characteristics of cavity backed microstrip antenna with double negative ( DNG ) substrates are studied in the paper .

研究了以双负材料为衬底的背腔微带天线的设计方法与电磁特性。

By using periodical condition the dispersion relation is obtained for 1D infinitely periodical photonic crystal composed of SNG or DNG .

对于SNG或DNG构成的光子晶体，利用周期性条件，进而得到了一维无限周期光子晶体的色散关系。

The numerical simulation of the new type of DNG is studied by using FDTD method and CST software , and the physical mechanism analysis for this structure is discussed in detail .

用时域有限差分法和CST软件对该新型结构进行了模拟对比，并对其物理机理进行了分析，解释了其双负效应发生的原因。

The FDTD method is capable of correctly computing electromagnetic propagation and scattering in DNG . Wave propagation in DNG is simulated by one-dimension FDTD .

用FDTD方法数值模拟了电磁波在双负介质中的传播及电磁散射。

The study on theory and application of DNG structure is at initial stage . The DNG structure is applied to waveguide antenna and arrays in this thesis to enhance the gain of antennas .

双负媒质结构的理论和应用研究刚刚起步，本文将其应用于波导天线及其阵列中，用以提高天线的增益。

Compact electromagnetic band-gap ( EBG ) structure and double negative ( DNG ) structure are new types of electromagnetic material presented recently , which have greatly potential applications on the field of microwave and optics .

紧致型电磁带隙结构和双负媒质结构都是近年来提出的新型电磁材料，在微波和光学领域都有巨大的应用前景。

Except double negative ( DNG ) media , it is well known that photonic crystals ( PCs ) can also support negative refraction . And recently it has been suggested that chiral media could also support negative refraction under certain conditions .

除了介电常数和磁导率同时为负的双负介质外，光子晶体可以支持负折射也是为人所熟悉的，另外在特定条件下手征介质可以支持负折射近来也被提出了。

The gain patterns of the rectangular waveguide antenna and arrays with and without DNG structure are compared . Simulation and experimental results show that the forward gain of antenna is enhanced distinctly and backward radiation is somewhat restrained with the DNG structure .

比较了双负媒质结构加载前后矩形波导天线及其阵列的增益方向图，数值仿真和测量结果表明，天线的前向增益得到显著的提高，同时对后向辐射也有一定的抑制效果。

In this thesis , the electromagnetic ( EM ) wave propagation and scattering in double negative medium ( DNG ) are investigated with finite-difference time-domain ( FDTD ) method and CST software . The applications of DNG to reduce RCS are discussed .

本论文用时域有限差分（FDTD：Finite-DifferenceTime-Domain）方法和CST软件对电磁波在双负介质中的传播和散射特性进行了研究，探讨其在隐身方面的应用。

The inversion formulas of constitutive parameters of DNG in waveguide are given through revising the NRW method according to the difference between DNG and ordinary medium . Thirdly , the periodization influences of the three kinds of truncation boundary are analysed according to the image theory .

针对双负介质与普通介质的不同，对NRW方法进行了修正，推导出了波导中双负介质的电磁参数反演公式。根据镜像原理，理论分析了三种截断边界对周期化的影响。