A NEW APPROACH ON IDENTIFICATION OF BOUNDARY PARAMETER FOR A TWODIMENSIONAL DIFFUSION SYSTEM

This paper presents a new approach of the boundary parameter identification of adiffusion system.The system model is governed by a two-dimensional parabolic problem,which involves an unknown boundary parameter.Identifiability of the boundary parameterand the new approach are discussed briefly,which show that the new approach can overcomenot only the ill-posedness of the nonlinear output least square method but also the difficultyof numerical computation of the nonlinear output least square estimate due to the existenceof the local minima of the performance functional,Finally,some numerical examples aregiven.     

一种加快最小二乘参数估计的参数跟踪速度的措施

本文探讨了如何加快最小二乘参数估计的参数跟踪速度问题。为此目的提出了一种自动调整其“遗忘因子”值的措施。仿真计算的结果证实,所采取的这种措施是可行而且是有效的。     

绝经前的健康女性中瘦体重、体脂含量和骨密度的关系

从长沙地区的汉族人群中征集了878名年龄在20~45岁绝经前的健康女性样本,采用Hologic QDR4 500 W双能量X射线骨密度仪(DXA)来测量腰椎(L1-4)、髋部和全身其他部位的骨密度、瘦体重、体脂含量.应用SAS软件进行瘦体重和体脂含量与骨密度的Pearson相关分析和多元回归分析.发现瘦体重和体脂含量都与骨密度正相关,而且瘦体重对骨密度变异的贡献是8.0%~11.4%,体脂含量对骨密度变异的贡献是0.2%~2.5%.表明在绝经前的健康女性中,瘦体重是比体脂含量更加重要的决定骨密度变异的因素.     

廊固凹陷西部大兴砾岩体油气藏形成条件研究

大兴砾岩体位于廊固凹陷西部，为冲积扇——扇三角洲沉积体系，是本区具潜力的勘探目标，通过岩石录井资料和三维地震资料分析，建立了砾岩体剖面识别模式，并划分出两种不同的砾岩体油藏类型，揭示了本区砾岩体的三维空间分布特征，研究表明：大头断层下降盘砾岩油气藏有着比较好的盖层和油源条件，本区存在两种不同的砾岩油气藏类型可供勘探，并将油藏描述技术成功地运用于砾岩油气藏的勘探．     

一种动态系统稳态优化的抗干扰调优方法

为解决存在干扰情况下的功态系统稳态调优问题,提出了一种新的目标函数及其梯度的辨识方法,并以此给出了抗干扰调优方案。理论分析和仿真结果表明:该法可在较强的输入动态扰动和外干扰下,自动移动工作点至最优点,并具有最优点跟踪性能。     

振动筛面上振动着的物料对筛体(横梁)的载荷识别

本文应用试验模态分析方法研究了振动着的物料的载荷效应,发现了这种载荷是一系列冲击力的作用,导出了动载荷的表达式,发现了高次谐波共振现象,这些结果可用于振动筛框的动强度设计中。     

Metabonomic analysis of hepatitis B virus-induced liver failure： identification of potential diagnostic biomarkers by fuzzy support vector machine

Hepatitis B virus （HBV）-induced liver failure is an emergent liver disease leading to high mortality. The severity of liver failure may be reflected by the profile of some metabolites. This study assessed the potential of using metabolites as biomarkers for liver failure by identifying metabolites with good discriminative performance for its phenotype. The serum samples from 24 HBV-indueed liver failure patients and 23 healthy volunteers were collected and analyzed by gas chromatography-mass spectrometry （GC-MS） to generate metabolite profiles. The 24 patients were further grouped into two classes according to the severity of liver failure. Twenty-five eommensal peaks in all metabolite profiles were extracted, and the relative area values of these peaks were used as features for each sample. Three algorithms, F-test, k-nearest neighbor （KNN） and fuzzy support vector machine （FSVM） combined with exhaustive search （ES）, were employed to identify a subset of metabolites （biomarkers） that best predict liver failure. Based on the achieved experimental dataset, 93.62% predictive accuracy by 6 features was selected with FSVM-ES and three key metabolites, glyeerie acid, cis-aeonitie acid and citric acid, are identified as potential diagnostic biomarkers.     

纸质题库无纸化的新方法

叙述了将纸质标准化题库转化为可在计算机程序中调用的数据库文档的新方法。该方法在Windows2000环境上实现,应用软件为清华紫光TH-OCR9.0、Office2000、VFP6.0。需要一台扫描仪支持。     

对从甘蔗根部分离的固氮成团泛菌的研究

从甘蔗根部分离的固氮菌株Ｗ１１，经细菌自动鉴定系统根据９６个生化试验指标，鉴定为成团泛菌。该菌株耐酸，耐高蔗糖浓度（３０％），产酸使培养基的工低到ＰＨ４．４１，３．１ｍｍｏｌＮＨ４ＮＯ３或５８．８ｍｍｏｌＮａＮＯ３能抑制固氮酶活性。     

牛和人的长骨密质骨哈佛氏系统的比较研究

本文对牛和人胫骨骨干密质骨的微细结构进行了研究．应用扫描电镜观察到牛骨中存在着完全哈佛氏系统，丛状骨及哈佛氏系统与板层骨相间三种结构形式，得到牛和人胫骨密质骨中哈佛氏系统沿径向分布的规律