Experimental Observation on Orientation Relationship between Binary Cd5.7Yb Quasicrystal and its Crystalline Approximant Cd6Yb

Similarity in the electron diffraction patterns of the Cd5.7 Yb icosahedral quasicrystal and its cubic approximant Cd6 Yb crystal is studied in detail by using transmission electron microscopy. The icosahedral twofold axes are parallel to the cubic （1ττ^2） （τ= 1.618…） or （0 0 1） directions, the icosahedral pseudo-twofold axes are parallel to the cubic （15 21 25） directions, the icosahedral threefold axes are parallel to the cubic 〈1 1 1〉 and the icosahedral fivefold are parallel to the cubic 〈0 1 τ〉 directions. Based on those observations a general stereographic projection is given to illustrate the exact orientation relationship.     

Holographic storage scheme based on digital signal processing

In this paper, a holographic storage scheme for multimedia data storage and retrieval based on the digital signal processing (DSP) is designed. A communication model for holographic storage system is obtained on the analogy of traditional communication system. Many characteristics of holographic storage are embodied in the communication model. Then some new methods of DSP including two-dimensional (2-D) shifting interleaving, encoding and decoding of modulation-array (MA) code and method of soft-decision, etc. are proposed and employed in the system. From the results of experiments it can be seen that those measures can effectively reduce the influence of noise. A segment of multimedia data, including video and audio data, is retrieved successfully after holographic storage by using those techniques.     

红外液晶光阀光学调制特性研究

介绍了液晶光阀的结构及其光学调制原理,利用光阀对读出光反射率计算公式,分析了液晶光阀参数对其光学调制特性的影响,通过理论计算,得到整层液晶分子扭曲角和液晶层厚度与液晶光阀调制能力的关系,分析给出了适合对中波和长波红外波段仿真的红外液晶光阀参数。     

Particle Transport with Asymmetric Unbiased Forces and Entropic Barrier

Transport of a Brownian particle moving along the axis of a three-dimensional （313） symmetric and periodic tube is investigated in the presence of asymmetric unbiased forces. It is found that in the presence of entropic barrier, the asymmetry of the unbiased forces is a way of inducing a net particle current. The particle current is a peaked function of temperature, which indicates that the thermal noise may facilitate the transport even in the presence of entropic barrier. There exists an optimized radius at the bottleneck at which the particle current takes its maximum value. The current can be influenced by the slope of tube walls and there exists an optimized slope for which the particle current takes its maximum value.     

Polymer White-Light-Emitting Diodes with High Work Function Cathode Based on a Novel Phosphorescent Chelating Copolymer

Polymer white-light-emitting diodes are fabricated based on the blend of poly[9,9-di-（2-ethylhexyl）-fluorenyl-2, 7- diyl]-end capped with polysilsesquioxane （PFO） and a chelating copolymer of poly[（9,9-bis（3′-（N,N-dimethylamino） propyl）-2, 7-fluorene-alt-2, 7-（9,9-dioctylfluorene） ）-co- [2, 7-（9,9-dioctlyfluorene）-alt-5,5-bis（2-（4-methyl-l-naphtha- lene） pyridine-C^2,N） iridium （III） acethylacetonate]] （PFN-NaIr）. The device with the sole aluminium cathode is able to produce a comparably white electroluminescence efficiency of 1.31 cd/A to that of the device using low work function cathodes （such as Ba, Ca, etc.）. The CIE coordinates of the white light emission consisting of red, green and blue three components are nearly at （0.34, 0.35）. The mechanism of the white light emission from the device with the AI cathode is investigated, which is related to the efficient injection of electrons through the interface of PFN-Nalr/AI.     

电容器放电的演示

这个演示可以说明电容器的几个基本性能,使得这些性能有趣和可信。应该特别指出电容器本来就是一个把电介质放在金属板间做成的。以静电场形式储存能量的系统。     

緃波演示实驗的改进

高中物理課本第二册第24頁图15及师范学校物理学(試用本)第一册第182頁图8—20,都載有关于纵波的演示装置图,同时都指出用手推拉弹簧的一端,会看到密部和疏部沿弹簧向另一端移动。这个实驗实际做起来有困难,效果也不好。在实践中我們曾改进了它,現将改进后的装置和做法介紹出来,以供参考。用直径d为0.65毫米的铁絲,繞成直径D約为5厘米、螺距/約为0.4厘米、长L約为60厘米的弹簧(繞制时,可先繞在一个腊紙筒上,然后取下,再在弹簧某端的一环中交連上三条鉄絲)。繞妥后用棉綫把弹簧悬掛在一根横杆上,大約每隔6厘米掛一根綫,全部装置如图所     

铵光卤石气固反应法制备无水氯化镁

铵光卤石气固反应法制备无水氯化镁;ouig     

Comments on Three-point explicit compact difference scheme with arbitrary order of accuracy and its application in CFD

The explicit compact difference scheme,proposed in Three-point explicit compact difference scheme with arbitrary order of accuracy and its application in CFD by Lin et al.,published in Applied Mathematics and Mechanics (English Edition),2007,28(7),943-953,has the same performance as the conventional finite difference schemes.It is just another expression of the conventional finite difference schemes. The proposed expression does not have the advantages of a compact difference scheme. Nonetheless,we can more easily obtain and implement compared with the conventional expression in which the coefficients can only be obtained by solving equations,especially for higher accurate schemes.