On the Entangled Fractional Fourier Transform in Tripartite Entangled State Representation

Based on the newly constructed two mutually conjugate 3-mode entangled states of continuum variablesin three-mode Fock space we introduce entangled fractional Fourier transform (EFFT) for the tripartite entangled staterepresentations, which are not a direct product of three 1-dimensional FFTs. The eigenmodes of EFFT are obtained,which is different from the usual Hermite polynomials. The EFFT of the three-mode squeezed state is derived.     

Laplacians and the Cheeger Inequality for Directed Graphs

We consider Laplacians for directed graphs and examine their eigenvalues. We introduce a notion of a circulation in a directed graph and its connection with the Rayleigh quotient. We then define a Cheeger constant and establish the Cheeger inequality for directed graphs. These relations can be used to deal with various problems that often arise in the study of non-reversible Markov chains including bounding the rate of convergence and deriving comparison theorems.Received September 8, 2004     

Tunable microlens arrays using polymer network liquid crystal

A tunable-focus microlens array based on polymer network liquid crystal (PNLC) is demonstrated. The PNLC was prepared using an ultraviolet (UV) light exposure through a patterned photomask. The photocurable monomer in each of the UV exposed spot forms an inhomogeneous centro-symmetrical polymer network which acts as a lens when a homogeneous electric field is applied to the cell. The focal length of the microlens arrays is tunable with the applied voltage.     

空气隙间隔格兰型棱镜偏光器透射光强扰动的温度效应

线偏振光正入射的情况下，空气隙间隔格兰型棱镜的透射光强随旋转角出现周期性增强的扰 动.扰动的出现影响了透射偏振光的质量.研究表明，透射光强对入射角有着敏感的依赖关系 .实验中空气隙间隔格兰型棱镜的振动引起入射角在棱镜的结构角附近作微小变化，从而导 致了透射光强的扰动.讨论了温度的变化对扰动大小的影响.给出了减小扰动的有效方法. 关键词： 偏光棱镜 热光效应 干涉 扰动     

Diffusion of 99Tc in granite under aerobic and anoxic conditions

Summary  Vezetéknév     

Oligomeric guanidine synthesis assisted by TFA-sensitive arylsulfonylthiourea

Through arylsulfonyl activation of thiourea, efficient synthesis of oligomeric guanidines can be achieved in either solution or solid-phase. Incorporation of TFA-sensitive arylsulfonyl groups, such as Pbf, during the synthesis greatly simplifies deprotection procedures for obtaining the final oligomeric guanidine products.     

光纤陀螺随机误差的滤波方案的探讨

范跃祖，宁文如，刘剑．光纤陀螺随机误差的滤波方案的探讨．数理统计与管理，１９９７，１６（４），２９～３２．光纤陀螺是新一代的光学陀螺仪，它的性能决定着惯性参照系统的精度。光纤陀螺的误差分为两大类。一类是有规律的，另一类是随机的。本文提出了两种新的用于光纤陀螺随机误差补偿的Ｋａｌｍａｎ滤波方案，考虑了两种随机模型：（Ⅰ）角速度变化为等随机的；（Ⅱ）角速度变化为等随机加速的。仿真结果表明，第二种方案对噪声起到了很好的抑制作用和滤波效果     

类锂硅离子软X射线激光研究

在激光等离子体典型参数条件下，利用碰撞－辐模型计算了类锂硅离子５ｆ－３ｄ和４ｆ－３ｄ跃的粒子数反转比率和激光增益系数。讨论了不同热带条件和不同冷却速度下，激光增益系统数的变化。计算结果表明，高功率，短脉冲激光生产的高温等离子体在快速冷却条件下能产生软Ｘ射的线激光增益。     

The Existence of Periodic Orbits for Higher Dimensional Autonomous Systemswith Small Perturbations

ＴｈｅＥｘｉｓｔｅｎｃｅｏｆＰｅｒｉｏｄｉｃＯｒｂｉｔｓｆｏｒＨｉｇｈｅｒＤｉｍｅｎｓｉｏｎａｌＡｕｔｏｎｏｍｏｕｓＳｙｓｔｅｍｓｗｉｔｈＳｍａｌｌＰｅｒｔｕｒｂａｔｉｏｎｓＪｉａｎｇＬｉｑｉｎｇ（蒋里强）；ＺｈｏｕＹｉ（周毅）；ＦａｎＹｅ（范晔）（...     

Interfacial effects on stress distribution in model composites

Raman mechanical spectroscopy was used to examine interfacial effects on the stress distribution in model polydiacetylene fiber/epoxy composites. Epoxy release agents were coated on fiber surfaces to modify the interfacial adhesion properties. The modified fiber surfaces were then characterized by scanning electron microscopy and x-ray photoelectron spectroscopy as well as optical microscopy. No difference in the maximum stress value or stress distribution was observed for the two types of fibers, coated or uncoated, used in composites. This suggests that adhesion properties at the composite interface do not affect tensile stress transfer efficiency nor, therefore, the composite tensile modulus along the fiber axis direction in uniaxial composites. Experimental data were also compared with theoretical calculations assuming perfect bonding between fiber and matrix, and idealized frictional force transfer mechanism at the fiber–matrix interface.