随机泛函微分系统的脉冲镇定

针对一般的随机泛函微分系统,提出了可脉冲均方一致渐近镇定和可周期性脉冲均方一致渐近镇定的定义.利用Lyapunov函数和一个一维线性脉冲时滞系统的渐近稳定性条件,得到了随机泛函微分系统可周期性脉冲均方一致渐近镇定的充分判据,并给出了脉冲控制律的具体设计方法.脉冲控制函数为正比例函数,脉冲发生间隔则依赖于系统本身的参数和选取的脉冲控制函数的比例系数.数值例子表明所设计的脉冲控制器是有效的.     

Acidithiobacillus ferrooxidans对黄铜矿和镍黄铁矿的浸出

以黄铜矿和镍黄铁矿为研究对象,初步探讨了Acidithiobacillus ferrooxidans对黄铜矿和镍黄铁矿的浸出.结果表明:有细菌参与下,黄铜矿的浸出率是无菌体系浸出率的2.41倍;镍黄铁矿的浸出率是无菌体系浸出率的1.91倍,细菌在矿物的浸出过程中起到了很好的促进作用.浸出过程中会有黄色的黄钾铁矾(K[Fe3(SO4)2(OH)6])沉淀产生,黄钾铁矾附着在矿体表面,产生"钝化现象",严重阻碍矿物的氧化.     

提高大学生体育信息意识初探

信息是现代人生存能力的素质,当代大学生必须具备良好的体育素质和信息素质才能适应社会的发展。体育信息是一个动态过程,强化体育信息意识,加强大学生体育信息素质教育,明确体育信息素质教育的内容、责任与优势,才能切实促进我国体育科技水平的提高。     

Coordination-theoretic approach to modelling grid service composition process

A grid service composite process is made up of complex coordinative activities. Developing the appropriate model of grid service coordinative activities is an important foundation for the grid service composition. According to the coordination theory, this paper elaborates the process of the grid service composition by using UML 2.0, and proposes an approach to modelling the grid service composition process based on the coordination theory. This approach helps not only to analyze accurately the task activities and relevant dependencies among task activities, but also to facilitate the adaptability of the grid service orchestration to further realize the connectivity, timeliness, appropriateness and expansibility of the grid service composition.     

带有积分边界条件的微分方程的数值求解算法

在区间[0,1]中研究带有积分边界条件的微分方程数值求解问题,给出了这类方程精确解的表达式,证明了近似解一致收殓到精确解,误差随结点数的增加单调递减.算例验证了本文算法是有效的.     

双密度制约的Holling Ⅳ型捕食系统的定性分析

研究一类具有HollingⅣ型双密度制约的捕食系统,并分析该系统平衡点的性态,得到了唯一正平衡点的全局稳定性和极限环存在唯一性的充分条件.     

湖南省滑坡地质灾害现状、发育特征、成生因素及防治对策研究

湖南省是我国地质灾害比较严重的省份之一,属地质灾害高易发区。灾害类型繁多,分布广泛,灾情严重。本文重点分析湖南省滑坡地质灾害的现状、发育特征、成生因素及防治对策,对今后滑坡地质灾害的研究和防灾工作具有重要的指导意义。     

Characteristics of recent temperate glacier fluctuations in the Parlung Zangbo River basin,southeast Tibetan Plateau

Little is known about recent variation of temperate glaciers on the Tibetan Plateau, although they are of particular theoretical and practical interests in terms of climate change and water supply. The study of glacier mass balance and terminus variation for six temperate glaciers in the Parlung Zangbo River basin, southeast Tibetan Plateau, shows the facts of the overall negative mass balance and the continued terminus retreat from 2005/2006 to 2007/2008. The mass balances of smaller glaciers were more negative compared to larger glaciers. Referring the trend of glacier mass balance in the Hengduan Mountains, the Himalayas and glacier shrinkage in southeast Tibetan Plateau, the mass loss and recession of temperate glacier in this region are expected if the current climate condition continues.     

冷驯化对黑腹绒鼠能量代谢和产热的影响

以南方常见种之一黑腹绒鼠(Eothenomeys melanogaster)为对象,经过(5±1)℃冷驯化0,7,14,21,28 d后,测定其体质量、能量收支、基础代谢率(BMR)和非颤抖性产热(NST)等代谢产热指标及褐色脂肪组织(BAT)的产热活性变化.结果表明:体质量随冷驯化时间的延长缓慢下降;摄入能、消化能、可代谢能、BMR和NST呈现增加的趋势,21 d达到最高水平或趋于稳定;随着冷驯化时间的逐渐增加,BAT的相对质量、线粒体蛋白含量及细胞色素C氧化酶(COX)活性均明显提高,21 d达到最大值.说明在寒冷胁迫下,黑腹绒鼠采用增加能量摄入和提高产热能力等对策维持能量的收支平衡.而黑腹绒鼠代谢和产热模式的特点与其自身的生活习性及生境条件密切相关.     

PH3 monitoring in Arctic and Dalian bay areas

<正> In this paper,we use pre-column 2 times low-temperature cryo-trap enrichment—gas chromatography(GC) /nitrogen and phosphoms detector(NPD)to detect and analyze phosphine in Arctic pole area forthe first time.The results show phosphine exists in all of the samples in Arctic pole biosphere and phosphineconcentration in Arctic atmosphere is between 18.54～132.18 ng/m~3,almost the same as that inAntarctic atmosphere;phosphine concentration in Dalian bay sea surface sediments is between 116.8～554.3 ng/kg,almost the same as that reported in Jiao-zhou bay.Our research of phosphine will shednew light on the mechanisms showing how the phosphorus supplement influences the biogeochemical cycleand global warming.