二维等熵流Chaplygin气体的平面δ-激波

研究等熵流Chaplygin气体的初值为2个常状态的二维黎曼问题.使用平面波法和特征分析方法,在适当的广义Rankine-Hugoniot条件和熵条件下,构造出该黎曼问题的5类平面波解,这些解由后向(前向)疏散波、后向(前向)激波、接触间断以及δ-激波构成.     

稻作文化影响下的壮族传统体育

运用文献资料、逻辑分析、田野调查等研究方法,对敢壮山上壮族传统体育项目及周边生态环境、文化背景进行调查分析。结果表明：敢壮山上的体育项目受稻作文化的影响颇深,不仅在体育项目上,而且在其特点和功能上都有＂那＂文化的印记。     

Retail default prediction by using sequential minimal optimization technique

This paper employed sequential minimal optimization (SMO) to develop default prediction model in the US retail market. Principal components analysis is used for variable reduction purposes. Four standard credit scoring techniques—naïve Bayes, logistic regression, recursive partitioning and artificial neural network—are compared to SMO, using a sample of 195 healthy firms and 51 distressed firms over five time periods between 1994 and 2002. The five techniques perform well in predicting default particularly one year before financial distress. Furthermore, the prediction still remains sound even 5 years before default. No single methodology has the absolute best classification ability, as the model performance varies in terms of different time periods and variable groups. External influences have greater impacts on the naïve Bayes than other techniques. In terms of similarity with Moody's ranking, SMO excelled over other techniques in most of the time periods. Copyright © 2008 John Wiley & Sons, Ltd.     

羽毛球多球训练中血乳酸指标的应用分析

多球训练是羽毛球训练常用的重要手段之一,通过心率、血乳酸等指标对多球训练不同训练方式进行监测,分析不同方式之间的差别,并关注血乳酸值的个体差异。结果表明:不同训练内容以及轮转方式对机体的刺激强度不同;相同训练负荷下个体之间的血乳酸值存在差异,应针对性地安排训练。     

融合视觉的柔性虚拟夹具辅助遥操作研究

提出了一种融合视觉的柔性虚拟夹具方法,用于辅助未知环境中的机器人遥操作.通过引入柔性系数实现机器人倾向于理想运动方向程度的调节,保证已知环境中遥操作的安全性和操作性能.利用基于颜色识别的视觉方法对环境中的障碍物大小和位置进行识别,从而实现对柔性虚拟夹具的柔性系数自动选择,扩展该方法应用于未知环境中的遥操作,保证未知环境遥操作的安全性和操作性能.在未知环境中进行了曲线跟踪避障实验,验证了该方法的有效性.     

城市意象的形成、表现与管理

当今的城市建设如火如荼，色彩斑斓，却很少有章法，既失去了个性，也没有了特色，众多城市沦为千城一面的下场。造成这一局面的原因很复杂，其中一个很重要的原因，就是我们缺乏对城市意象的提炼和规划，由此造成了城市规划、建设和管理的万乱之源。为此，我们需要从更高的层次上认识城市意象的重要引领和控制意义，从历史、现实和未来结合的层面上，探讨城市意象的提炼和规划，从而使得一座城市变得丰满而有个性，并且为自己赢得适宜的发展空间。     

向量值约化子空间超仿射小波对偶框架的构造

利用Fourier变换和周期化技巧,给出Fourier域上L~2(R~d,C~L)中约化子空间上的超仿射小波对偶框架的一个充分条件,从而将L~2(R~d)中约化子空间上的结果推广到向量值空间L~2(R~d,C~L)的约化子空间上.     

混凝土结构课程实验教学的探索

提出混凝土结构课程实验环节的改革措施。该措施主要注重学生自主设计实验、操作实验、分析实验结果并得出实验结论,通过综合性实验加深理解所学的理论知识,培养学生严谨缜密的工作作风以及对所学知识综合应用的能力。     

Diversity, regulation, and genetic manipulation of plant mono- and sesquiterpenoid biosynthesis

Among plant secondary metabolites, terpenoids are the most abundant and structurally diverse group. In addition to their important roles in pollinator attraction and direct and indirect plant defense, terpenoids are also commercially valuable due to their broad applications in the cosmetic, food, and pharmaceutical industries. Because of their functional versatility and wide distribution, great efforts have been made to decipher terpenoid biosynthetic pathways, to investigate the molecular mechanism determining their structural diversity, and to understand their biosynthetic regulation. Recent progress on the manipulation of terpenoid production in transgenic plants not only holds considerable promise for improving various plant traits and crop protection but also increases our understanding of the significance of terpenoid metabolites in mediating plant-environment interactions.