CH_4、CO_2与O_2制合成气的研究 Ⅱ工艺条件的影响

在固定床反应器中考察了１２％Ｎｉ－５％ＲＥ－２％Ｃｕ－２％Ｌｉ／Ａｌ２Ｏ３（ｍａｓｓ）催化剂在ＣＨ４、ＣＯ２与Ｏ２催化氧化重整制合成气反应中催化剂粒径、工艺操作条件（空速与温度）及原料气配比对反应的影响，确定了较佳的操作条件：催化剂粒径２０～４０目，反应最佳温度为８００℃，ＳＶ＝４×１０４ｍｌ／（ｇ·ｈ）。同时看到在不同的原料气配比的条件下该催化剂的活性亦很稳定，不仅达到了反应平衡，且产物Ｖ（ＣＯ）／Ｖ（Ｈ２）比有很强的调变性。     

256比特的混沌分组密码

由于密码分析研究的进展及DES自身的弱点,原64比特的DES将不能作为数据加密的标准算法而长期存在。在原来工作的基础上,本文提出了256比特的分组密码方案。密码算法由基于混沌映射的数字滤波器构造。     

不连续增强镁基复合材料的界面行为

综述了近年来国内外关于Ａｌ２Ｏ３短纤维、ＳｉＣ晶须、ＳｉＣ颗粒、Ｂ４Ｃ颗粒增强镁基复合材料的界面结构及其对复合材料性能影响的研究进展，并对今后的研究提出了一些看法。     

An algorithm for the three-dimensional packing problem with asymptotic performance analysis

The three-dimensional packing problem can be stated as follows. Given a list of boxes, each with a given length, width, and height, the problem is to pack these boxes into a rectangular box of fixed-size bottom and unbounded height, so that the height of this packing is minimized. The boxes have to be packed orthogonally and oriented in all three dimensions. We present an approximation algorithm for this problem and show that its asymptotic performance bound is between 2.5 and 2.67. This result answers a question raised by Li and Cheng [5] about the existence of an algorithm for this problem with an asymptotic performance bound less than 2.89. This research was partially supported by FAPESP (proc. 93/0603-1) and by CNPq/ProTeM-CC, project ProComb (proc. 680065/94-6).     

Optimized Schwarz methods without overlap for highly heterogeneous media

In this paper an original variant of the Schwarz domain decomposition method is introduced for heterogeneous media. This method uses new optimized interface conditions specially designed to take into account the heterogeneity between the sub-domains on each sides of the interfaces. Numerical experiments illustrate the dependency of the proposed method with respect to several parameters, and confirm the robustness and efficiency of this method based on such optimized interface conditions. Several mesh partitions taking into account multiple cross points are considered in these experiments.     

Decisive arrival law parameters and a general finite capacity queueing problem

This paper addresses the problem of finding the parameters of the arrival law which most significantly influence expected occupation and loss of a finite capacity queue. The input process is supposed to be ergodic and wide sense stationary. We show that it is mostly possible to fit an MMPP(2) to the decisive parameters of observational data. Numerical examples illustrate the importance of the decisive parameters, called key parameters, and also show the accuracy of the proposed fitting procedure. Finally, in the appendix we present the solution of the finite capacity queueing problem with Special Semi Markov Process (SSMP) arrivals and a general service strategy.     

THE ANALYSIS OF THE SEPARATED LAYERS ALGORITHM BY DOMAIN DECOMPOSITION METHOD

From the principle of of the Domain Decomposition Method (DDM), we analyse the 2nd-order linear elliptic partial differential problems and link the Separated-Layers Algorithm (SLA) with DDM. The mathematical properties of SLA and numerical example are presented to obtain satisfactory computation results. For general linear differential ones, also are the structure of SLA and its characteristics discussed.     

三脉冲不等强度激光片光源的研制及应用

本文报道了最近研制成功三脉冲不等强度调Q红宝石激光片光源系统.利用小颗粒对片光源90°方向的散射光对动态颗粒场进行高速摄影,从底片中能够精确直观地判断微小颗粒的瞬时分布、运动方向、速度和加速度情况.     

高能粒子辐照对零膨胀微晶玻璃光学性质和面形光学稳定性的影响

研究了高能电子，高能质子对ＶＯ２微晶玻璃辐照前后光性质和面形光学稳定性的影响，研究结果表明，高能电子辐照能引起微晶玻璃面形明显变化，且使ＶＯ２微晶玻璃强烈着色。高能质子辐照没引起面形明显变化，高能质子辐照对反射光谱特性没有影响。     

Cubic Bézier approximation of a digitized curve

In this paper we present an efficient technique for piecewise cubic Bézier approximation of digitized curve. An adaptive breakpoint detection method divides a digital curve into a number of segments and each segment is approximated by a cubic Bézier curve so that the approximation error is minimized. Initial approximated Bézier control points for each of the segments are obtained by interpolation technique i.e. by the reverse recursion of De Castaljau's algorithm. Two methods, two-dimensional logarithmic search algorithm (TDLSA) and an evolutionary search algorithm (ESA), are introduced to find the best-fit Bézier control points from the approximate interpolated control points. ESA based refinement is proved to be better experimentally. Experimental results show that Bézier approximation of a digitized curve is much more accurate and uses less number of points compared to other approximation techniques.