Mechanical Design and Research on Process of Air Suction Drawing System of Spunbonded Nonwoven

The design guideline for the air suction drawing system with auxiliary air was analyzed, a spunbonding nonwoven system named PADHL1 - 3200 was designed and polypropylene （PP） spunbonded nonwoven fabrics with excellent properties were achieved after many trial runs. On the other hand, the suction air velocity （VA） was calculated and the influence of VA on the bonding strengh of PP nonwoven fabrics was Studied as well. It was found that VA is 1.5 - 2.5 times of the spinning velocity. With the increase of VA, PP fibers become finer and the bonding strength of PP nonwoven fabrics increases as well.     

浅析营业杠杆系数及其经济应用

本文介绍了营业杠杆系数这一衡量企业经营风险的重要指标，对该指标的特性进行了较深入的分析和探讨。同时，还导出了利用该指标判断企业经营安全状态的方法。     

矩形截面钢筋混凝土简支梁的可靠性优化设计

本文在多个正态分布基本变量的情况下，建立了结构的可靠性优化设计数学模型，并采用机遇约束规划方法把该模型变换为一个等价的确定性非线性规划问题。最后给出了设计价格最小的矩形低配筋钢筋混凝土梁的可靠性优化设计实例     

两因素HJM模型下债券、期货、期权的定价

在HJM模型下考虑远期利率由2个独立布朗运动驱动的零息票债券的期限结构,给出零息票债券和债券期货的定价公式,以及债券期货期权的定价公式。     

一个可靠指标计算公式的误差分析

对美国桥梁设计规范中计算可靠指标的一个公式进行分析,认为该公式是近似的,并指出了其近似的原因。分别采用该公式和蒙特卡罗法计算可靠指标,计算结果表明该公式的误差高达30%,远远超出工程容许范围。因此在工程上应用该公式进行可靠指标计算是不合适的。     

Forecast accuracy after pretesting with an application to the stock market

In econometrics, as a rule, the same data set is used to select the model and, conditional on the selected model, to forecast. However, one typically reports the properties of the (conditional) forecast, ignoring the fact that its properties are affected by the model selection (pretesting). This is wrong, and in this paper we show that the error can be substantial. We obtain explicit expressions for this error. To illustrate the theory we consider a regression approach to stock market forecasting, and show that the standard predictions ignoring pretesting are much less robust than naive econometrics might suggest. We also propose a forecast procedure based on the ‘neutral Laplace estimator’, which leads to an improvement over standard model selection procedures. Copyright © 2004 John Wiley & Sons, Ltd.     

学术论文评审指标体系设计

介绍了学术论文评审表设计的原则和评审表的形式。结合多年办刊的实践。设计了一种简单实用的评审表，所设计的内容既有限定问题的选择回答，又留有审稿人自由发挥的空间。     

北京史与北京学

史以载道，学以至用。史和学之间的关系可以说是史为根基、学为干躯。北京历史的轨迹完整清晰，发展的方向亦具有不可改变之趋。长城、运河、阿尔泰山丝绸之路使北京具有其他城市所无法取代的特殊地位。历史奠定了现实，现实建造了未来。北京的历史、现实、未来决定了北京学是一门显学，有必用和大用。     

基于相对业绩比较的报酬契约与代理成本分析

有效的报酬契约是企业所有者激励经营者努力工作的最佳动力，该文在考虑了相对业绩比较信息条件下，运用委托代理理论探讨了将货币收入和享受闲暇作为经营者的激励物的最优报酬契约，分析了非对称信息条件下实施契约的代理成本，得出了经营者利润分享系数与影响因素之间的关系模型以及代理成本与影响因素之间的关系模型，该文还设计了经营者的股票期权激励机制，并地某些企业作了案例分析，文章阐明股票期权激励能够将经营者的长期行为和利益与企业的长期目标结合起来，是调动经营者积极性的有效手段。     

图的直积和字典积的Laplacian谱和Kirchhoff指数

由图G1、G2的Laplacian谱得到了它们的直积G1×G2和字典积G1[G2]的Laplacian谱,并计算了R(G1×G2)和R(G1[G2]).