微量元素硒的生理功能综述

硒作为人体必需微量元素,有多方面的生理功能。本文从环境中硒的分布、硒在人体内的代谢、硒与相关疾病、硒 与其它元素的关系、硒的需要量及来源、硒中毒及治疗等方面对硒进行了综述。     

Comparing and testing order relations between percentile residual life functions

We consider the problem of comparing and testing order relations between percentile residual life functions. We introduce R-R plots and processes and develop a general approach for this problem.     

关于课程与教学论功能的思考

课程与教学论既不能被看成某种课程与教学的描述,也不能被看成对现实课程与教学及其历史发展的某种思辨。课程与教学论的科学价值取决于两点:承认科学的假说性和确认课程与教学现实的问题性。学习和研究课程与教学论意味着发展对课程与教学现实提出问题的能力。课程与教学论要有活力,就必须干预课程与教学问题,从课程与教学变革、发展和进步的明确观点来规定课程与教学问题,并提出解决方案。课程与教学论研究者如果要肩负起学术建设和课程与教学改造的社会职责,发挥课程与教学论的应有功能,就必须将课程与教学论真正作为一门科学来对待,遵循课程与教学论学科发展的基本逻辑规则。     

计算机构造李亚普诺夫函数及其应用

本文叙述Brayton与Tong在动态系统的稳定分析中建立的计算机构造李亚普诺夫函数的算法,及Michel等人推广的这种算法,该方法所建立的程序有可能确定系统在平衡状态x=0的吸引域和研究互联系统的稳定性。     

唐翰林侍讲侍读学士考论

文章对中晚唐时翰林学士院中设置的侍讲学士、侍读学士进行考论,认为其与翰林学士共同构成唐时高层文士具有时代特色的文化职能,很值得从历史一文化的角度加以研究。     

略论入世后我国社会中介组织的建设

中国的入世首先是政府的入世,这就需要我国政府进一步转变职能。该文从探讨我国入世后政府职能转变过程中社会中介组织的作用入手,分析了目前我国中介组织的现状及存在问题,并提出了入世后我国社会中介组织如何进行建设的对策。     

Estimation of parameters in survey sampling: Optimality

Some recent works on estimation in survey sampling are analyzed and extended from the perspective of the theory of optimal estimating functions.     

Nonparametric estimation of discrete hazard functions

A smoothing procedure for discrete time failure data is proposed which allows for the inclusion of covariates. This purely nonparametric method is based on discrete or continuous kernel smoothing techniques that gives a compromise between the data and smoothness. The method may be used as an exploratory tool to uncover the underlying structure or as an alternative to parametric methods when prediction is the primary objective. Confidence intervals are considered and alternative techniques of cross validation based choices of smoothing parameters are investigated.     

状态变量带通滤波器的研究

本文采用状态变量法来综合有源滤波器,它模拟标准二阶传输函数构成二阶带通状态变量滤波器,用这种滤波器作为基本节电路,构成四阶带通、参差调谐四阶带通和参差调谐六阶带通滤波器。研究构成高阶带通滤波器的几种新颖方法。这类带通滤波器时于低频、基低频、高 Q 值和良好的矩形因数等场合是很有用的。     

ESTIMATION OF GUARANTEE TIME AND MEAN LIFE AFTER WARRANTY FOR TWO-PARAMETER EXPONENTIAL FAILURE MODEL

Suppose manufactured items have failure times distributed with the two-parameter exponential density function à-^le-(x-μ)/à (x≥μ≥0). The paper considers estimation of the guarantee time μ and mean life after warranty à. Properties of various estimators are given for both separate and simultaneous estimation of μ and à. Criteria for comparing estimators are entropy loss, LINEX loss, and (generalized) Pitman nearness.