世界城市区域发展的新形势

全球化与地方化是重塑世界格局的两大潮流。在全球化和地方化双重力量的作用下 ,世界经济发生了巨大的变化 ,城市区域获得了令人瞩目的发展 ,并出现了许多新情况、新特点 ,对世界政治经济产生了重大影响。从某种意义上讲 ,如今国际竞争的单位更多地体现为城市区域。研究世界城市区域发展的新形势 ,对推动我国城市区域建设具有重要借鉴意义     

明清湖北商品经济的发展状况

明清湖北商品经济的发展状况可从四个层面加以考察:第一,湖北粮食生产的商品化程度日益加深;第二,棉花、苎麻、茶叶、烟草等具有市场潜力的经济作物在湖北广泛种植;第三,湖北的商品流通日益活跃;第四,湖北的商品经济在晚清跃上新的台阶。同时应该看到,这种发展受到诸多限制:第一,清嘉、道年间后,人口过剩问题成为阻挠湖北社会进步的沉重包袱;第二,安土重迁、不习商贾,是湖北地区不利于商品经济发展的社会习俗;第三,广大边穷山区成为湖北经济增长的重负;第四,明清时期,湖北的市场发育虽然较之唐宋时期有所突破,但市场机制远不够完善。综上所述,明清湖北商品经济的发展水平不可高估。     

Development of a Standard Soil-to-Skin Adherence Probability Density Function for Use in Monte Carlo Analyses of Dermal Exposure

It has recently been suggested that "standard" data distributions for key exposure variables should be developed wherever appropriate for use in probabilistic or "Monte Carlo" exposure analyses. Soil-on-skin adherence estimates represent an ideal candidate for development of a standard data distribution: There are several readily available studies which offer a consistent pattern of reported results, and more importantly, soil adherence to skin is likely to vary little from site-to-site. In this paper, we thoroughly review each of the published soil adherence studies with respect to study design, sampling, and analytical methods, and level of confidence in the reported results. Based on these studies, probability density functions (PDF) of soil adherence values were examined for different age groups and different sampling techniques. The soil adherence PDF developed from adult data was found to resemble closely the soil adherence PDF based on child data in terms of both central tendency (mean = 0.49 and 0.63 mg-soil/cm²-skin, respectively) and 95th percentile values (1.6 and 2.4 mg-soil/cm²-skin, respectively). Accordingly, a single, "standard" PDF is presented based on all data collected for all age groups. This standard PDF is lognormally distributed; the arithmetic mean and standard deviation are 0.52 ± 0.9 mg-soil/cm²-skin. Since our review of the literature indicates that soil adherence under environmental conditions will be minimally influenced by age, sex, soil type, or particle size, this PDF should be considered applicable to all settings. The 50th and 95th percentile values of the standard PDF (0.25 and 1.7 mg-soil/cm²-skin, respectively) are very similar to recent U.S. EPA estimates of "average" and "upper-bound" soil adherence (0.2 and 1.0 mg-soil/cm²-skin, respectively).     

Unified Conditional Frequentist and Bayesian Testing of Composite Hypotheses

Testing of a composite null hypothesis versus a composite alternative is considered when both have a related invariance structure. The goal is to develop conditional frequentist tests that allow the reporting of data-dependent error probabilities, error probabilities that have a strict frequentist interpretation and that reflect the actual amount of evidence in the data. The resulting tests are also seen to be Bayesian tests, in the strong sense that the reported frequentist error probabilities are also the posterior probabilities of the hypotheses under default choices of the prior distribution. The new procedures are illustrated in a variety of applications to model selection and multivariate hypothesis testing.     

数学课进行德育教育浅探

数学课进行德育教育浅探陈玉芬（河南内乡师范）坚持对学生进行思想品德和政治教育，不仅是德育学科的任务，而且应当是各个学科教学的一项重要任务。作为研究现实世界数量关系和空间形式的科学的数学课的教学，它不只是教给学生解决日常生活和工作中的算数问题，也不仅仅...     

Bayesian estimates in a one-way ANOVA random effects model

Bayesian estimators of variance components are developed, based on posterior mean and posterior mode, respectively, in a one-way ANOVA random effects model with independent prior distributions. The formulas for the proposed estimators are simple. The estimators give sensible results for 'badly-behaved' datasets, where the standard unbiased estimates are negative. They are markedly robust as compared to the existing estimators such as the maximum likelihood estimators and the maximum posterior density estimators.     

Assessing gamma frailty models for clustered failure time data

Proportional hazards frailty models use a random effect, so called frailty, to construct association for clustered failure time data. It is customary to assume that the random frailty follows a gamma distribution. In this paper, we propose a graphical method for assessing adequacy of the proportional hazards frailty models. In particular, we focus on the assessment of the gamma distribution assumption for the frailties. We calculate the average of the posterior expected frailties at several followup time points and compare it at these time points to 1, the known mean frailty. Large discrepancies indicate lack of fit. To aid in assessing the goodness of fit, we derive and estimate the standard error of the mean of the posterior expected frailties at each time point examined. We give an example to illustrate the proposed methodology and perform sensitivity analysis by simulations.     

关于点集聚点的一个结果

关于点集聚点的一个结果苏子安（福建泉州电视大学３６２０００）著名的Ｂｏｌｚａｎｏ—Ｗｅｉｅｒｓｔｒａｓ定理指出；定理１Ｒｎ中的任一有界无穷集，都至少有一个聚点．这一定理中的“有界“性条件对于结论的成立至关重要．如果放弃这一条件，定理结论将不成立，Ｒ１...     

裂尖区塑性密度场的拟全量理论描述

本文采用拟全量理论，分析了裂尖区的的非比例加载情况，并从理论上导出了不同屈服程度下塑性能密度ＷＰ场的统一表达式，有限元场分析证实了此表达式的正确性。