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.     

具有中国特色的执政党建设理论的创立——兼谈改革开放30年党的建设的经验

改革开放的每一重大战略部署和伟大实践，都包含着党的建设的新举措和党的建设理论的新探索。党的建设的实践和理论的每一创新发展，也反过来推进和保证了中国特色社会主义经济、政治、文化、社会建设和各个领域的改革。中国共产党对历史方位转变和执政党建设理论的认识，已经达到了新的高度，提出要“深化对共产党执政规律的认识”这一命题，本身就是中国共产党在30年党的建设理论创新过程中，获得的一个重要成果。我们研究具有中国特色的马克思主义执政党建设理论。从根本上说，就是要认识执政规律，尊重执政规律，努力按照执政规律加强执政党建设，加强和改善党对中国特色社会主义事业的领导，完成党肩负的伟大历史使命。     

Optimal sampling for repeated binary measurements

The authors consider the optimal design of sampling schedules for binary sequence data. They propose an approach which allows a variety of goals to be reflected in the utility function by including deterministic sampling cost, a term related to prediction, and if relevant, a term related to learning about a treatment effect To this end, they use a nonparametric probability model relying on a minimal number of assumptions. They show how their assumption of partial exchangeability for the binary sequence of data allows the sampling distribution to be written as a mixture of homogeneous Markov chains of order k. The implementation follows the approach of Quintana & Müller (2004), which uses a Dirichlet process prior for the mixture.     

新农村建设类设计的重要源泉——解读传统徽派建筑聚落空间的创作手法

通过深层次地解读传统徽派建筑聚落空间的几点重要创作手法,强调了保存和发展传统建筑文化的重要性,并认为具有乡土价值的空间创作手法可以成为新农村建设类设计的重要源泉。     

时间如何前进——进化论随笔

中国古代"与时偕行"、"与时俱化"的观念,以取法天地四时的运行为基准,是一种四时循环论的变化观.我党提出的"与时俱进"思想的含义,是随着时代的前进而前进,和随着时代的变化而变化,体现了鲜明的时代创新精神,它的哲学基础是科学进化论.这一特征在语词上通过一个"进"字表达出来.虽然"与时俱进"和"与时俱化"只有一字之差,却体现了本质的超越.同时,这一表述通过对中国古代<易经>、<庄子>等经典的吸收,丰富了自身的思想内涵,也建立,了联接传统与现代的一道桥梁.当然,由于现代时间观念的一维性质,使得人们在批驳"直线进化论"的同时,易于陷入"时间进化论",而时间进化论实际上也是一种直线进化论,这也是需要警醒的.     

郑玄《尚书》训诂的谶纬化

郑玄是汉学的总结性人物,其《尚书》训诂,是东汉《尚书》学之代表。郑玄《尚书》训诂,融古文、今文、谶纬于一体,是两汉《尚书》学谶纬化范围扩大的最好例证。通过郑玄,我们可以知道,古今文《尚书》学的对立并不妨碍双方对谶纬的吸收,谶纬在郑玄手中变成整合古今文《尚书》学的桥梁。     

抗震救灾伟大斗争彰显中国人民伟大力量

中国人民与四川汶川地震自然灾害进行的伟大斗争，向全世界展示了中国共产党的坚强领导能力、中国特色社会主义伟大旗帜的巨大号召力、人民军队的强大战斗力、社会主义中国的厚实综合国力以及中华民族精神的蓬勃生机与活力。     

Nonresponse weighting adjustment using estimated response probability

To reduce nonresponse bias in sample surveys, a method of nonresponse weighting adjustment is often used which consists of multiplying the sampling weight of the respondent by the inverse of the estimated response probability. The authors examine the asymptotic properties of this estimator. They prove that it is generally more efficient than an estimator which uses the true response probability, provided that the parameters which govern this probability are estimated by maximum likelihood. The authors discuss variance estimation methods that account for the effect of using the estimated response probability; they compare their performances in a small simulation study. They also discuss extensions to the regression estimator.     

图式理论、学习策略与大学英语口语教学

本研究采用定量分析的方法,对84名天水师范学院非英语专业的学生的口语水平进行测试。根据图式理论,口语任务分为有关键词及句型提示类和无提示类,并对被试的学习策略使用情况做了调查,结果发现,口语任务有提示与无提示对学生的口语成绩有显著影响,这说明图式理论完全适用于大学英语口语教学。