Sampling Strategies for Toxic Air Contaminants

Annual concentrations of toxic air contaminants are of primary concern from the perspective of chronic human exposure assessment and risk analysis. Despite recent advances in air quality monitoring technology, resource and technical constraints often impose limitations on the availability of a sufficient number of ambient concentration measurements for performing environmental risk analysis. Therefore, sample size limitations, representativeness of data, and uncertainties in the estimated annual mean concentration must be examined before performing quantitative risk analysis. In this paper, we discuss several factors that need to be considered in designing field-sampling programs for toxic air contaminants and in verifying compliance with environmental regulations. Specifically, we examine the behavior of SO2, TSP, and CO data as surrogates for toxic air contaminants and as examples of point source, area source, and line source-dominated pollutants, respectively, from the standpoint of sampling design. We demonstrate the use of bootstrap resampling method and normal theory in estimating the annual mean concentration and its 95% confidence bounds from limited sampling data, and illustrate the application of operating characteristic (OC) curves to determine optimum sample size and other sampling strategies. We also outline a statistical procedure, based on a one-sided t-test, that utilizes the sampled concentration data for evaluating whether a sampling site is compliance with relevant ambient guideline concentrations for toxic air contaminants.     

初等数学与高等数学的融合

本文从高等数学对初等数学的渗透，高观点下的初等数学，高等数学对初等数学的直接指导作用三个方面阐述了初等数学与高等数学的融合。     

构建基于4C模式高校新型师生关系的探讨

随着教育改革的不断深入,建立与时代相适应的新型师生关系非常有必要.建立新型的师生关系,是构建和谐校园的坚实基础,是全面提高教育质量,实现高校可持续发展的重要条件.文章在分析师生关系现状的基础上,研究构建新型师生关系的动因,对如何构建基于4C模式的新型师生关系进行了探讨.     

面向基础教育课程改革的教师教育职前培养模式探析

在师范教育转型的过程中，师范院校应转变传统的人才培养观念。针对基础教育课程改革，积极进行教师教育职前培养模式创新探索，培养具有综合的学科知识和专业化教育水平的新型教师，适应基础教育课程改革的需要。     

融医学人文素质教育于生理学教学的探索

探讨如何把医学人文教育贯穿到生理学课程教学过程中．通过教师的引导和示范作用，培养适应时代需求具有高尚情操的高素质医学生。     

试论清代两湖地区书院的刻书业及其兴盛原因

历代书院刻印的图书,在版本学上称为"书院本"。其版本价值较高,历来倍受文士学者重视。清代两湖地区的书院兴盛且日益官学化,书院刻书业比较发达,留下大量作品。究其原因,主要包括社会、政治、经济、文化和学术五个方面。     

A qualitative comparative analysis of strategies for an ageing society, with special reference to pension and employment policies

The primary purpose of this study is to typify the respondent strategies of the OECD countries based on the interconnected structure of income and employment guarantees. More specifically, this article seeks to typify welfare policies into four types (welfare-to-work, welfare emphasis, labour emphasis, market emphasis) based on the leniency of the pension system and active state intervention in employment security. With the resultant four types, this article then places them as the dependent variable while incorporating per capita GDP, aged dependency ratio, pension maturity level, union density, constitutional structure index and degree of decommodification as causal variables. Through this process, this article aims to derive the decisive variable for each type through qualitative comparative analysis.     

浅谈舞蹈教育在审美教育中的地位

从审美教育的本质入手,采用理论和实例相结合的方式以及依托个人在亲身工作体验中的感受,阐述了舞蹈教育中所体现的审美教育以及怎样在舞蹈教育中培养学生的审美能力等几方面的问题,说明了舞蹈教育在审美教育中所占有的相当重要的地位。     

民族自治地方农村养老问题与对策初探——以黔东南州锦屏县为例

民族自治地方农村养老工作与构建社会主义和谐社会、社会主义新农村建设、“三农”问题等紧密相关，养老工作能否解决好直接影响到农村的社会稳定、社会的和谐发展和“三农”问题的解决。民族自治地方农村经济相对落后、经济发展不平衡、人口分布不均衡、农村老年人口日益增多、农民工大量外出等现实，给传统养老方式带来了历史性的冲击。这要求建立具有时代特色和地方特色的养老方式。本文在进行充分的实地调查、分析黔东南苗族侗族自治州锦屏县农村现行的养老方式现状、养老方式存在问题的基础上，结合当地实际情况和借鉴其他地方的成功养老方式，提出具体可行的对策。