利用二进制数算法寻找5个点的Ramsey图

用二进制数来表示完全图的各种组合,借助计算机编程可从完全图的各种组合中寻找出ramsey图。5个顶点的Ramsey图是最基本的Ramsey图,这种基本方法为寻找更复杂的Ramsey图提供了基础。     

堆石混凝土单轴受压应力-应变全曲线试验方法研究

为了研究堆石混凝土应力-应变全曲线,采用碟形弹簧与钢柱组合成附加刚性元件增强压力机的刚性,研究了碟形弹簧并联与串联联结装置的变形量和刚度以及实现单轴受压端部减摩措施,提出了一种堆石混凝土单轴受压应力-应变全曲线的试验方法。在混凝土压力试验机上进行了堆石混凝土立方体试件单轴受压试验,测得了堆石混凝土受压应力-应变全曲线。试件破坏形态表明,采用的端部减摩措施有效,测得的应力-应变曲线下降段验证了碟形弹簧与钢柱组合装置能够吸收试件破坏时混凝土压力试验机存储的变形能。研究结果为在混凝土压力试验机上进行堆石混凝土单轴受压应力-应变全曲线提供了可行、简便、经济的测试方法。     

Distributed election in complete networks

An improved version of Afek and Gafni's synchronous algorithm for distributed election in complete networks is given and anO(n) expected message complexity is shown. M.Y. Chan received her Ph.D. in 1988 from the University of Hong Kong, and her M.S. and B.A. degrees in computer science from the University of California, San Diego in 1980 and 1981, respectively. She is currently an Assistant Professor at the University of Texas at Dallas. Francis Y.L. Chin (S71-M76-SM85) received the B.Sc. degree in engineering science from the University of Toronto, Toronto, Canada, in 1972, and the M.S., M.A., and Ph.D. degrees in electrical engineering and computer science from Princeton University, New Jersey, in 1974, 1975, and 1976, respectively. Since 1975, he has taught at the University of Maryland, Baltimore Country, University of California, San Diego, University of Alberta, and Chinese University of Hong Kong. He is currently Head of the Department of Computer Science, University of Hong Kong. He has served as a program co-chairman of the 1988 International Conference on Computer Processing of Chinese and Oriental Languages (Toronto) and the International Computer Science Conference '88 (Hong Kong). His current research interests include algorithm design and analysis, parallel and distributed computing.     

基于量化规则格的关联规则渐进更新*

提出一种基于量化规则格的规则更新算法,重点讨论了在新增格节点的过程中规则更新的思想,实现在格的渐增生成过程中,相应的关联规则也得到渐进更新.最后给出简单实例说明规则更新算法的正确性.     

交流滤波器避雷器电气特性分析中不同仿真模型的影响

交流滤波器是直流输电系统的重要设备。主要分析仿真模型对交流滤波器用避雷器电气特性（过电压、电流和吸收能量）的影响,基于PSCAD电磁仿真程序,开展滤波器投入和交流滤波器母线接地故障下的建模及仿真计算。仿真结果表明：在交流滤波器投入工况下,采用单个滤波器大组模型（模型1）进行仿真时,在运滤波器的避雷器不动作,与实际情况不符;在滤波器投入及滤波器母线接地故障下,完整参数模型（模型3）中各组滤波器用避雷器过电压比原系统模型（模型2）和模型1降低可达21%,电流降低可达53%,但吸收能量升高可达56%。因此,若在绝缘设计中不采用完整参数模型,避雷器电压电流设计值会偏大,能量设计值会偏小,同时会在滤波器投入工况下忽略同大组其他交流滤波器的避雷器动作情况。     

纳米晶体Se的微观结构特征

本文采用Ｘ射线衍射和透射电子显微镜研究了纳米晶体Ｓｅ的微观结构特征．通过测定不同晶粒尺寸的纳米晶体Ｓｅ的点阵参数ａ和ｃ，发现纳米晶体Ｓｅ中存在晶格畸变，畸变量与晶粒尺寸有关．得到了纳米晶体Ｓｅ中晶胞体积变化与晶粒尺寸的关系．并由点阵参数计算出纳米晶体Ｓｅ的键长．用非晶态Ｓｅ中的无规链折叠的晶化机制解释了纳米晶体Ｓｅ中晶格畸变现象．     

Pd纳米微粒的晶格参数和结合能的尺寸形状效应研究

利用分子动力学的方法研究了球形和立方体形Pd纳米微粒的晶格参数和结合能．研究表明，在一定的形状下，纳米微粒的晶格参数和结合能随着微粒尺寸的减小而降低；在一定尺寸时，球形纳米微粒的晶格参数和结合能要高于立方体形的纳米微粒的相应量．通过线形拟合分子动力学模拟的数据，定量的给出了形状效应对于纳米微粒晶格参数变化的贡献量约为总贡献量的7％，而形状效应对于结合能变化量的贡献为总变化量的25％．再次证明了具有自由表面的Pd纳米微粒的晶格发生收缩，模拟值与实验结果一致．     

氢对Ti合金的Debye温度和晶格常数的影响

使用X射线衍射仪测定出不同氢含量的Ti-30Mo合金的Debye特征温度值以及晶格常数的变化,结果表明随着氢含量的增加,Debye特征温度相应地减小而晶格常数增加,证实了氢含量的增加会导致金属原子间键合力的减弱,从而造成金属脆化。     

Creep-induced local lattice parameter changes in a monocrystalline nickel-base superalloy

The γ-γ lattice mismatch of specimens of the monocrystalline nickel-base superalloy SRR 99 has been measured by a high-resolution X-ray diffraction technique for the undeformed state and after high-tem-perature creep deformation. During creep deformation beyond the minimum creep rate (total strain =0.5%), the lattice mismatches, measured in and perpendicular to the [001] stress axis, respectively, un-dergo changes in opposite directions. This reflects the buildup of a complex deformation-induced triaxial state of internal stress in the phases y and γ. The overall resolved shear stresses that act in γ and y due to the combined action of the external and internal stresses are estimated, and the conditions under which cutting of the γ phase by dislocations should occur are discussed.     

含油废水旋流处理配套回用工艺技术研究

目前多数油田的含油废水经过旋流器及其配套技术处理后可直接用于回注，而回注水主要指标是控制废水中的含油量与悬浮物量。在现场试验地，利用两级静态旋流器串联加过滤装置或其他配套技术工艺进行净化，测试结果十分理想。作者总结了现场实验工艺的优选设计、试验及应用。结合各种旋流处理的配套工艺与典型实验数值对比结果，优选出满足生产需求的配套回用工艺，为建立以旋流器为核心水处理设备的配套新工艺及环保范基地奠定了基础，提高了经济效益。