甲基丙烯酸C_7～C_9酯的基闭转移聚合

研究了甲基丙烯酸Ｃ_７～Ｃ_９酯的基团转移聚合。聚合必须在８０℃以上进行，讨论了聚合条件对聚合速率、分子量、分散性及转化率的影响。     

椭圆板的大挠度问题

本文在圆薄板大挠度问题摄动解法(1948).(1954)的基础上,求得了椭圆板大挠度问题的摄动解.本文的公式推导是1957年以前完成的,由于某些原因,长期未得发表.1959年见到Nash-Cooley以摘要形式发表的类似工作,但只有λ=a/b=2的数值结果.这里将原先推导的正确至二级近似的分析公式以及计算结果发表.其中包括泊桑比v=0.25,0.30,0.35,椭圆半径比λ=1,2,3.4.5的全部计算结果,以备工程设计计算之用.     

Order statistics on optically interconnected multiprocessor systems

Processor arrays with an optical bus are introduced for parallel computation in this paper. We use the order statistics problem as an example to demonstrate how to design efficient parallel algorithms on such systems. Besides proposing a new algorithm on the model, some basic data movement operations involved in the algorithm are discussed. We believe that these operations can be used to design other parallel algorithms on the same model. Time analysis indicates that order statistics can be done more efficiently on a linear array with a pipelined optical bus than with an electronic bus. The initial results are promising, and the author believes that optical buses may emerge as a powerful communication mechanism for connecting large parallel computer systems in the near future.     

含2,3-二氯-5,6-二氰基对苯醌(DDQ)或其自由基离子(DDQ~)的多元配合物研究

通过联苯甲酰双缩肼（Ｌ）与不同金属乙酸盐［Ｍ（ＯＡｃ）２］及２，３－二氯－５，６－二氰基对苯醌自由基离子（ＤＤＱ－·）反应，合成了３个分子式为（ＭＬ）２＋（ＤＤＱ－·）２（Ｍ＝Ｍｎ、Ｚｎ、Ｃｄ）的三元配合物及２个分子式为（ＭＬ）２＋（ＤＤＱ－·）（ＯＡｃ－）（Ｍ＝Ｎｉ、Ｐｂ）的四元配合物．元素分析确定了它们的组成，经红外光谱、紫外－可见光谱及摩尔电导的测定对其配位情况进行了讨论．另将丁二酮双缩肼（Ｌ）与不同金属乙酸盐［Ｍ（ＯＡｃ）２］，及中性ＤＤＱ反应，合成了分子式分别为（ＭＬ）２＋（ＤＤＱ－·）（ＯＡｃ－）（Ｍ＝Ｃｕ、Ｃｄ）、（ＭＬ）２＋（ＤＤＱ）（ＯＡｃ－）２（Ｍ＝Ｃｏ、Ｎｉ）及（ＨｇＬ）２＋（ＤＤＱ）１．５（ＯＡｃ－）２的五个四元配合物．经元素分析、红外光谱、紫外－可见光谱，对它们进行了表征．固体电导的测定结果表明，含中性ＤＤＱ的配合物均属半导体范畴，其中Ｈｇ配合物的室温粉末固体电导率达３．７×１０－４Ω－１ｃｍ－１．     

D(β)-vertex-distinguishing total coloring of graphs

A new concept of the D(β)-vertex-distinguishing total coloring of graphs, i.e., the proper total coloring such that any two vertices whose distance is not larger than β have different color sets, where the color set of a vertex is the set composed of all colors of the vertex and the edges incident to it, is proposed in this paper. The D(2)-vertex-distinguishing total colorings of some special graphs are discussed, meanwhile, a conjecture and an open problem are presented.     

大气光通信中大气闪烁时间平滑效应研究

利用大气闪烁的时间平滑效应,增加光电探测器曝光时间是克服大气闪烁对大气光通信的瞄准、捕获、跟踪链路影响的有效途径之一.基于科尔莫戈罗夫谱,导出了弱湍流起伏区无限平面波和球面波的大气闪烁时间平滑因子的一般表达式,并且用几何光学近似得到了在大孔径和小孔径接收情况下的时间平滑因子近似表达式.在孔径远大于菲涅耳区尺度时,平面波和球面波的时间平滑因子的近似表达式与精确表达式的误差分别小于6%和3%.分析结果表明,孔径越小,时间平滑效应越显著,并且菲涅耳区尺度对时间平滑效应影响的程度也随着孔径的增加而减弱.     

Experimental long-distance decoy-state quantum key distribution based on polarization encoding

We demonstrate the decoy-state quantum key distribution (QKD) with one-way quantum communication in polarization space over 102 km. Further, we simplify the experimental setup and use only one detector to implement the one-way decoy-state QKD over 75 km, with the advantage to overcome the security loopholes due to the efficiency mismatch of detectors. Our experimental implementation can really offer the unconditionally secure final keys. We use 3 different intensities of 0, 0.2, and 0.6 for the light sources in our experiment. In order to eliminate the influences of polarization mode dispersion in the long-distance single-mode optical fiber, an automatic polarization compensation system is utilized to implement the active compensation.     

New Sixth-Order Compact Schemes for Poisson/Helmholtz Equations

Some new sixth-order compact finite difference schemes for Poisson/Helmholtz equations on rectangular domains in both two- and three-dimensions are developed and analyzed. Different from a few sixth-order compact finite difference schemes in the literature, the finite difference and weight coefficients of the new methods have analytic simple expressions. One of the new ideas is to use a weighted combination of the source term at staggered grid points which is important for grid points near the boundary and avoids partial derivatives of the source term. Furthermore, the new compact schemes are exact for 2D and 3D Poisson equations if the solution is a polynomial less than or equal to 6. The coefficient matrices of the new schemes are $M$-matrices for Helmholtz equations with wave number $K≤0,$ which guarantee the discrete maximum principle and lead to the convergence of the new sixth-order compact schemes. Numerical examples in both 2D and 3D are presented to verify the effectiveness of the proposed schemes.     

Convergence Rate of Solutions to a Hyperbolic Equation with $p(x)$-Laplacian Operator and Non-Autonomous Damping

This paper concerns the convergence rate of solutions to a hyperbolic equation with $p(x)$-Laplacian operator and non-autonomous damping. We apply the Faedo-Galerkin method to establish the existence of global solutions, and then use some ideas from the study of second order dynamical system to get the strong convergence relationship between the global solutions and the steady solution. Some differential inequality arguments and a new Lyapunov functional are proved to show the explicit convergence rate of the trajectories.     

八节点等参元滑动接触算法的改进

分析认为采用八节点等参元计算滑动接触问题时,往往存在较大的接触应力计算误差的主要原因在于这种单元具有两种不同的节点。为此,本文提出了双模拟接触边界法,即分别采用两种不同的节点,形成两个模拟接触边界,并限制“从接触边界”上的节点只能和“主接触边界”上其同类节点形成的模拟接触边界形成接触关系,从而有效的减小了采用八节点等参元计算滑动接触问题时的误差。