介质

A series of theoretical and experimental studies on the microstrip patch antennas with dielectric superstrates is carried out systematically. Firstly, a comprehensive survey of the microstrip antenna technology and its theories are presented. Then, two analysis techniques, named as the spectral domain Green's function method and the spectral domain integral equation method are developed. The SDGF method is a simplified analysis technique, which takes advantage of the spectral domain immittance approach to find the dyadic Green's function for the stratified media, and obtains the complete closed-form formulas for radiation patterns, directivity, efficiency, gain etc. Some interesting calculated results are presented. The SDIE method is capable of determining resonant frequency, radiation characteristics, input impedance etc, for the covered microstrip patch antennas. Comparing with other full-wave analyses it reduced computation and mathematical labour remarkably. The singularities near the pole location of the surface-wave modes and the difficulty of the integral computation over infinite range of oscillating integrands are dealt with actively and documented well. Results predicted by the SDIE method agree extremely well with our experimental results for resonant frequencies of various superstrates. The superstrate effects on impedance and radiation characteristics also have been investigated experimentally so that the gap due to lack of measured data and computed results for multi-layered superstrate has been filled to some degrees and two useful observations have been achieved for weakening the resonant frequency shift and optimizing the microstrip antenna gain. As a meaningful application, the design and analysis of a 4×4 patch array are introduced.

实用微带天线普遍加介质覆盖层来防护热，物理损伤和环境影响，也可能在飞行或严酷气候条件下自然形成覆盖层本论文对带介质覆盖层的微带贴片天线系统地作了一系列理论和实验研究首先，对微带天线技术和理论作了全面的综述然后，发展了两种分析方法，称为谱域格林函数法和谱域积分方程法SDGF法是一种简化的分析技术，它利用谱域导抗法来求得分层媒质的并矢格林函数，并得出方向图、方向性系数、增益等参数的完整的闭式公式，给出了一些令人感兴趣的计算结果SDIE法能确定介质覆盖微带天线的谐振频率、辐射特性和输入阻抗等与其它全波分析方法相比，它明显减小了计算量和数学工作量已有效地处理了表面波模极点附近的奇异性和对振荡的被积函数的无限区间积分计算的困难对于不同覆盖层情况下的谐振频率，由SDIE法所预示的结果与我们的实验结果吻合得很好对于覆盖层对阻抗和辐射特性的影响也已作了实验研究这在某种程度上填补了缺少实验数据和计算结果之间的间隙，并得出了缓解谐振频率偏移和优化天线增益的两点有用的结论作为有意义的应用，介绍了一个4×4元矩形贴片天线阵的设计和分析。

The basic properties of elastic wave propagation in quadratic inhomogeneous damage materials are discussed by examples.

介质中的波的传播理论在国内外已得到广泛的研究[4-6]，但以往的文献大多研究的是均匀介质或分层均匀介质中的波的传播问题[7]。

Computation result shows that the lossy material front edged metal wing with a V shaped interface have a better effect to reduce the backscatter RCS, and the interior angle of interface have a very important role in this stealth effect.

在这部分中，本文讨论了吸波介质前缘翼面在金属-介质界面和吸波介质前缘电磁参数对后向RCS的影响，重点讨论了界面为V字形时夹角与RCS的关系。

The stability of algorithm, the condition of absorbing boundary and free surface boundary, the grid dispersion and the process of source are discussed in details. The numerous simulations of wave propagation are carried out in isotropic media, transversely isotropic media and anisotropic media induced by fractures. The difference between anisotropic and isotropic effects on surface records is analysized.

接着讨论了有限差分算子的稳定性和收敛性，以及吸收边界条件、自由边界条件、数值频散和震源的处理，对各向同性介质、横向各向同性介质以及裂隙引起的各向异性介质中传播的弹性波场进行了数值模拟，分析了多波多分量数据中的各向异性效应以及各向同性在地表地震记录中的反映。

On the basis of analysis and comparison of conventional and some modern dielectric loss measurement methods in this paper, considering the difficulty consist in the dielectric loss measurement, such as the problem of the locale measurement of dielectric loss the suffering the interference of the electric field in the electrified wire net, the influence of harmonics and the leakiness of frequency spectrum due to the change of the frequency in power supply etc. a new measurement method which the frequency conversion anti-jamming technology combines the fundamental waves phase detachment method is presented.

论文在分析了传统介质损耗测量方法和现代介质损耗测量方法的基础上，针对介质损耗检测中存在的技术问题，如现场测量时工频电网强电场干扰问题、高次谐波影响问题、供电电源频率改变所引起的频谱泄漏和栅栏效应等问题，提出了采用变频抗干扰技术和基波相位分离法相结合的新型测量方法。

A method, apparatus and computer readable medium for managing recording medium defects and a defect managed recording medium.

一种管理记录介质缺陷的方法、设备和计算机可读介质以及一种缺陷被管理的记录介质。

In this paper,the absorption property of the left-handed material rectangular waveguide was studied by use of the perturbation method,and other novel properties were revealed.

采用微扰法研究了左手介质矩形波导的吸收特性。由于色散方程的限制，左手介质波导不能传输基模，它的吸收特性也与右手介质矩形波导明显不同。

The kind of soil that we like to use is a combination of peat moss and pearl light.

通常我们喜爱采用的混合介质组合是peat moss和pearl light，泥炭土是非常非常贫饥且略酸的介质，而中性的珍珠石只是用来当作增加透气的介质，您可以在以泥炭土为基础的情况下，随意的去搭配混合使用，像是用矽砂来代替珍珠石也行，或是将泥炭土、珍珠石和矽砂一起混用，又或是加入sphagnum moss…等等诸如此类的方式。

But internal reflections an the boundaries of active medium can drastically enhance the onset of ASE, particularly if these reflections lead to a close path, i.e., a ray that is reflected upon itself. In the case, we have a strong feedback mechanism and as soon as the gain in the laser medium exceeds the reflection losses parasitic oscillations will set in.

但自发辐射的存在使得放大器工作介质会在信号光到达前开始发射激光，并且工作介质边缘的内反射能显著增大ASE的发射，尤其当这些反射能导致产生封闭路径时更是这样，当激光介质内的增益超过损耗时，就建立起寄生振荡。

According to the effect of relative permittivity εr on the pulse propagation velocity in lossy dielectric space and the effect on the turnround time of signal between the antenna and the buried objects, it is presented that lossy dielectric space can be transformed into free space and the simulation results abtained from free space can also be amended to lossy dielectric space.

对探地雷达的微波全息成像法进行了分析研究，根据有耗介质空间中的εr 对脉冲传播速度的影响，以及对脉冲在收发天线与目标之间的往返时间的影响指出：可将有耗介质空间转化到自由空间，再将自由空间中的计算结果修正到有耗介质空间。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。