离散大系统解的有界性与周期解的存在性

本文分别利用向量Ｌｙａｐｕｎｏｖ函数方法和标量Ｌｙａｐｕｎｏｖ函数方法，给出了判定离散大系统解的有界性与周期解的存在性的充分条件，并讨论了一类具有非线性时变周期离散大系统的平稳振荡存在性问题．     

Bound lipids in lacustrine sediments in Guchenghu Lake, East China

Conclusion Lipids present in different modes of occurrence in lacustrine sediments vary obviously in their composition. The ester-bound and amide-bound lipids are more likely to be derived from autochthonous input such as bacteria, algae and fungi in the lake, and they were more stable than the free lipids in the process of early diagenesis. Bound lipids record the more actual information about the paleoclimatic and paleoenvironmental changes. Amide-bound P-hydroxy fatty acids can be used as a fingerprint of the past bacterial communities which is informative to the paleoenvironment.     

亚甲基兰的生物污泥吸附及胞外聚合物作用

对比研究了活性污泥和厌氧污泥对染料亚甲基兰的吸附性能,并考察了胞外聚合物(EPS)以及外层溶解性胞外聚合物(SEPS)和内层固着性胞外聚合物(BEPS)在此过程中所起的作用.结果表明,活性污泥中的EPS,SEPS,BEPS以及厌氧污泥中的EPS,BEPS对染料哑甲基兰的吸附更符合Langmuir等温式,厌氧污泥中的SEPS则更符合Freundlich 模型.活性污泥和厌氧污泥中SEPS绝对吸附量均大于BEPS的绝对吸附量,分别为14.1倍和5.8倍.但由于单位质量活性污泥和厌氧污泥中BEPS的质量均远大于SEPS,故活性污泥和厌氧污泥EPS对染料亚甲基兰的吸附主要是BEPS的吸附所贡献.     

基于界模型的真相关反馈信息检索

建立了一种表达用户信息需求的界模型,通过计算信息需求的上边界、下边界,确定信息需求的需求域.该模型从语言学的角度出发,通过挖掘语言的内涵和外延来表达语言的含义.用户的查询请求有其内涵和外延,信息需求域正是通过表达查询请求的内涵和外延来反映用户的真实信息需求.在信息检索时,计算文档与信息需求域的相似度,并根据相似度对文档进行排序.在实际检索时,采用用户真实相关反馈机制,该相关反馈机制得到的是真相关文档,因而可以更好地表达用户的信息需求.使用Lemur工具进行的对比分析实验表明,界模型下的真相关反馈信息检索具有较理想的效果.     

一种含整数型两层决策问题的求解方法

本文利用拉格朗日松驰技巧为两层决策问题构造了简单的线性定界函数，针对上层决策变量为０－１变量的两层决策问题，提出了一种分枝定界算法。文中给出的算例说明了算法的有效性。     

方程(axm+1)/(ax+1)=yn的正整数解

设a,m是大于1的正整数,证明:当m>2,方程(axm 1)/(ax 1)=yn仅有有限多组解(x,y,n)适合min(x,y,n)>1,而且这些解都满足yn相似文献   

具有指数型标量势和矢量势的Klein-Gordon方程和 Dirac方程的束缚态

在指数型标量势与矢量势下，严格求解了s波的Klein-Gordon方程和Dirac方程，给出了波函数的Bessel函数表述，并导出了能谱所满足的方程组。     

THE EXPONENTIAL BOUND OF THE SURVIVAL FUNCTION ESTIMAATOR FOR RANDOMLY TRUNCATED AND CENSORED DATA

ＴＨＥＥＸＰＯＮＥＮＴＩＡＬＢＯＵＮＤＯＦＴＨＥＳＵＲＶＩＶＡＬＦＵＮＣＴＩＯＮＥＳＴＩＭＡＡＴＯＲＦＯＲＲＡＮＤＯＭＬＹＴＲＵＮＣＡＴＥＤＡＮＤＣＥＮＳＯＲＥＤＤＡＴＡＺＨＵＹｕｊｉｅ（ＨｕｚｈｏｕＴｅａｃｈｅｒ＇ｓＣｏｌｌａｇｅ，Ｈｕｚｈｏｕ３１...     

Optimal Component Types for the Design of Construction Processes

Within the project preparation phase, experienced professionals manually map design information onto process information with the aim to develop realistic and practical schedules. Unfortunately, the mapping itself is neither part of any underlying data model nor is it supported by current scheduling tools. As a consequence the process of setting up the data model for a schedule is still not supported formally. Huhnt and Enge described a modelling technique that addresses the missing linkage between design and process information[1]. The approach makes use of so called component types. These are template sub-processes that describe the fabrication procedure of typical building components. Decomposing the building into com-ponents and assigning a component type to each component allows for formal support while scheduling. Depending on the decomposition of the building into components and the complexity of the involved component types the specification effort differs. The question about optimal component types arises: Which layout of building components and component types results in minimal specification effort? This paper presents a branch and bound algorithm to determine optimal component types. For a given schedule, which has been modelled based on component types, all possible decompositions into sub-processes are determined. During the decomposition process the encountered configurations are compared. Those with minimal specifica-tion effort are registered. Theoretical and practical examples are examined and discussed.