多孔有机盐单晶的合成及各向异性质子导电性能

以cis,cis-1,3,5-三氨基环己烷·3HBr和均苯四甲酸在室温下通过离子键构筑了具有规整形貌和大尺寸的晶态多孔有机盐CPOS-10, 其具有较好的热稳定性和永久多孔性. 得益于规整形貌及大尺寸单晶, 首次实现了对多孔有机盐单晶各向异性质子导电性能的研究, 并结合晶体结构探索了各向异性质子导电的机理. 结果表明, 水分子浓度对CPOS-10质子电导率的大小具有重要作用, 骨架内水分子浓度高的晶面更易于与极性基团构成氢键网络, 促进质子传导, 利用此网络的质子传导具有更高的质子电导率. 因此, 骨架内水分子的不均匀分布是导致单晶各向异性质子导电的主要原因. 对CPOS-10单晶各向异性质子导电性能的探索可为研究多孔有机盐的质子导电机理提供重要的依据.     

含各向异性左手材料的一维Thue-Mores准周期结构的反射带隙

采用传输矩阵法,研究了由各向同性右手材料和各向异性左手材料组成的Thue-Morse准周期结构的反射带隙,分析了入射角、偏振和晶格比例缩放因子对反射带隙的影响.结果表明该结构存在一个全方向反射带隙,该带隙的宽度由TE模的低频带边缘和TM模的高频带边缘决定.当在该结构中插入一层缺陷时,在全方向带隙中出现一条缺陷模.对TE模,缺陷模的位置受入射角的影响很弱,而对TM模,缺陷模的位置随入射角的增大,向高频方向移动.     

Rayleigh Scattering for An Electromagnetic Anisotropic Medium Sphere

Based on the scales theory of electromagnetic waves, the analytical expression of electrical fields inside an anisotropic medium sphere is studied. Differential scattering cross section and radar cross section （RCS） for an anisotropic spherical target are presented. The correctness of the obtained results is tested. The simulation results show that the scattering of an anisotropic sphere has the property of a dipole radiation under the condition of Rayleigh scattering. The larger the dielectric constant is, the stronger the dipole scattering is. Anisotropy in magnetism only has an effect on differential RCS. These results provide a theoretical base for the identification of anisotropic targets.     

Thermal Entanglement of an XY Two-Qutrit Spin Chain with Dzialoshinski-Moriya Interaction

The effect of Dzialoshinski-Moriya （DM） interaction on thermal entanglement of an XY two-qutrit spin chain is investigated. We find that DM interaction and the anisotropy parameter can enhance quantum thermal entanglement to a maximal value individually. However, when both of them take large values, the entanglement is not enhanced, but is destroyed. Our analysis will shed some light on the understanding of the effect of the DM interaction on thermal entanglement of an XY two-qutrit spin chain.     

Application of Equivalent Air Gap Method in Uniaxial Crystal Plate

The equivalent air gap method is a simple way to trace the ray propagation in an isotropic medium, but it cannot be applied to an anisotropic medium. We present the exact general expressions of the equivalent air gap thicknesses and the displacements for the plane-parallel uniaxial crystal plates. They are also suitable for the isotropie medium. This method is useful when one determines whether certain size plane-parallel plates can be fitted into the available air of an optical system, and also in the prism system design.     

Photonic band gap from periodic structures containing anisotropic nonmagnetic left-handed metamaterial

<正>We demonstrate a photonic band gap(PBG) from one-dimensional(1D) periodic structures created by a double-layer unit cell with an air layer and an anisotropic nonmagnetic left-handed metamaterial(LHM) layer whose permittivity elements are partially negative.The requirements imposed on the materials and structures to realize a PBG are derived when the frequency is above or below the cutoff frequency,and the transmission properties of the PBG are discussed by utilizing 4×4 transfer-matrix method with dispersive semiconductor metamaterial.     

Theoretical analysis of the anisotropy of the magnetization of the Ho^3＋ ion in holmium iron garnet single crystals

The spontaneous magnetization of the Ho^3＋ ion in holmium iron garnet （HoIG） single crystals in the temperature range of 4.2-294K along the directions [111], [110], and [100] are calculated, taking into account the effects of six magnetically inequivalent sites occupied by the Ho^3＋ ions based on the quantum theory. The calculated results show that the magnetization of the Ho^3＋ ion in HoIG is obviously anisotropic. The theoretical results ave in agreement with those of experiments. A primary interpretation of the anisotropy of magnetization of the Ho^3＋ ion in HoIG is put forward.     

各向异性作用下合金定向凝固界面稳定性的渐近分析

采用渐近分析方法对考虑了界面能各向异性的单相二元合金平界面定向凝固过程进行了线性稳定性分析，得到了特定条件下的零级、一级渐近解，并通过对长波段渐近解的讨论得出了适用于整个波段的色散关系.分析表明零级渐近解等效于成分过冷理论，而一级渐近解则与M-S稳定性理论一致.在稳定状态控制参数(抽拉速度和温度梯度)的选择图中，界面能各向异性增大了不稳定区域，且在高速和高温度梯度时的影响更强.     

具有垂直磁各向异性的TbCo／Cr非晶磁化膜

采用不加偏压的磁控溅射方法,制备了具有垂直磁晶各向异性的TbCo/Cr非晶垂直磁化膜,并且就Cr底层对TbCo膜磁性能的影响进行了研究。研究发现TbCo磁性层的厚度以及Cr底层的存在都会影响TbCo薄膜磁晶各向异性能的大小。对于厚度为120 nm,并且带有180 nm厚度Cr底层的Tb31C69薄膜而言,其磁晶各向异性能高达4.57×106 erg·cm-3,而对于同样厚度的Tb31C69薄膜,当它没有带Cr底层时,其磁晶各向异性能只有3.24×106 erg·cm-3。扫描电镜的观测结果表明,带有Cr底层的TbCo薄膜具有柱状结构。正是TbCo薄膜内的柱状结构导致了其磁晶各向异性的增强。