基于Malmquist指数的高校科研效率的实证分析

针对高校科研效率成为高校科研管理中的核心问题,并为高校科研发展的规划提供科学依据,提出了高校科研的动态效率测度的方法。该方法是Malmquist指数与数据包络分析的结合,获得对高校科研效率的动态测度,评价各高校的生产力水平在两期之间的变化情况,并通过Malmquist指数分解能获得高校科研的经济效率和技术效率,找出生产力变化的原因,为效率改进指明了方向。通过应用实例以说明该方法的有效性和适用性。     

基于Agent多用户参与的虚拟地理环境

Agent(智能体)由于有着与人类相似的行为模型,因而可应用于在有多用户参与的虚拟地理环境(VGE)中,并成为VGE领域当前研究的难点、热点问题。本文首先分析了VGE中多用户交互五个层次的特性;然后提出了将VGE系统和多智能体系统(MAS)结合的四种方法:松散耦合、紧密耦合、直接互操作耦合、非直接互操作耦合,并设计了对等和集中两种系统的体系结构。     

Change in the sedimentary environment of Wanquan River Estuary,Hainan Island,China

Pb geochronology and sediment core profiles of organic carbon, total sulfur and organic carbon isotope (d 13C) values were used to reconstruct the local environ-mental history of the Shamei Lagoon, located in the Wan-quan River Estuary, eastern Hainan Island, China. Totalsulfur and d 13C values decreased upwards in the top 30 cm of a sediment core that spanned the last 200 years of deposi-tion. Total sulfur concentration and d 13C values respectively decreased upward from 1.92% to 0.36%, and -20.63?to -23.64? The C/S ratio in the 19th century and earlier was relatively stable in the range of 0.47—0.80, and there was a positive correlation between organic carbon and total sulfur. Since around 1900 AD, the C/S ratio increased rapidly to a maximum of 3.94, but no simple correlation was found be-tween organic carbon and total sulfur during this more re-cent period. These results indicated that before 1800 AD, the lagoon had a fully marine character, and the location of to-day抯 Wanquan River Estuary was an open embayment.From 1800 to 1900, the salinity of Shamei Lagoon decreased noticeably. The amount of seawater which could enter thelagoon decreased gradually as the Yudai spit grew. Today,seawater scarcely affects the lagoon; it is essentially a fresh-water basin.     

独立随机序列的第κ个最大值的矩收敛

设｛Ｘ＿ｎ，ｎ≥１｝为独立同分布序列，公共分布函数为Ｆ（ｘ），为第ｋ个最大值。在一定条件下，讨论了第ｋ个规范化最大值的矩收敛性，得到定理若Ｆ∈Ｄ（Ｈ），则ｎ→∞时     

关于Von Mises条件的注记

ＶｏｎＭｉｓｅｓ（１９３６）在一定条件下给出了独立同分布随机变量序列｛Ｘ＿ｎ｝之分布函数Ｆ（ｘ）属于三大吸引场的充分条件。受Ｇａｌａｍｂｏｓ（１９８７）文章的启发，在一定限制下，使ＶｏｎＭｉｓｅｓ条件也成为Ｆ∈Ｄ（Φ＿ａ）及Ｅ∈Ｄ（Φ＿ａ）的充要条件。     

关于为一组点定中心的问题

作者考虑如下的为一组点定中心的问题：设ｘ１，．．．，ｘｍ是平面上的一组点，需要求得一个点ｘ，使得诸ｘｉ与ｘ的距离的偏差最小，今年对偏差的不同的度量方法，问题可归结为不同的最优化问题。本文分析了三个这样的问题，它们分别可表示为线性ｍｉｎ ｍａｘ问题和ｄ．ｃ．规划问题，文中还讨论了可能的求解这些问题的数值方法。     

Indicators of δ13C and δ18O of gas hydrate-associated sediments

The analyses of δ13C and δ18O of gas hydrate-associated sediments from two cores on Hydrate Ridge in Cascadia convergent margin offshore Oregon, eastern North Pacific show the values of d 13C from -29.81‰ to -48.28‰ (PDB) and d 18O from 2.56‰ to 4.28‰ (PDB), which could be plotted into a group called typical carbonate minerals influenced by the methane in cold venting. Moreover, the values of d 13C and d 18O show a consistent trend in both cores from top to bottom with increasing of d 13C and decreasing of d 18O. This trend could be explained as an effect caused by the anaerobic oxidation of methane (AOM) in depth and the oxygen fraction during the formation of gas hydrate in depth together. These characteristics of d 13C and d 18O indicate that the gas hydrate-associated sediments are significantly different from the normal marine carbonates, and they are deeply influenced by the formation and evolution of gas hydrate. So, the distinct characteristics of d 13C and d 18O of gas hydrate-associated sediments could be undoubtedly believed as one of parameters to determine the presence of gas hydrates in other unknown marine sediment cores.     

提高圆柱平摩擦轮传动效率的探讨

本文给出了圆拉平摩擦轮传动效率,的一般表达式和卸载圆柱平摩擦轮楔紧角α的表达式,阐述了卸载圆柱平摩擦轮传动的工作原理和设计摩擦轮传动时提高传动效率的途径。     

拱坝坝上放线技术探讨

简述了“坝上等弦等角放线法”在古石水电站枢组大坝施工放线中的应用,总结了坝上放线法的应用效果,分析了在“三心拱坝”等其它坝型中的推广应用,对今后拱坝施工放线提供一种新的方法。     

图的圆色数等于其色数的充分条件

图G的圆色数xc（G）（也称为星色数）是图的色数的一种推广,给出了图的圆色数等于其色数的一些充分条件。