三峡库区次级河流富营养化及其生态治理

三峡水库蓄水水位已达165米,其水环境性质为半封闭型的缓流水体,水体自净能力下降.库区次级河流水质的状况直接影响着三峡库区的水环境与生态安全.在分析库区次级河流水体富营养化现状与发生条件的基础上,结合国内外河流整治的生态观念和思路,对库区次级河流污水生态工程治理技术进行了的初步探讨.     

Measures of individual risk attitudes and portfolio choice: Evidence from pension participants

We use a large non-student sample to test how distinct measures of risk-attitudes relate to each other, to demographic characteristics and to real-life risk taking in the financial domain. These measures, namely the Bomb Risk Elicitation Task (BRET), self-reported willingness to take risks in general, the choice in a hypothetical lottery, the score in the Domain Specific Risk-Taking (DOSPERT) scale, appear to be positively correlated and exhibit a certain degree of consistency. Furthermore, a subset of these measures is driven by similar demographic characteristics as such that males are more risk seeking and risk-aversion increases with age. Using extensive data on the retirement portfolios of the participants during the years 2008–2014, we find that all of these measures are positively correlated with the riskiness of individual portfolios. The self-reported willingness to take risks in general appears to be the most relevant measure in predicting actual risk-taking behavior.     

Improving variance function estimation in semiparametric longitudinal data analysis

We propose an efficient and robust method for variance function estimation in semiparametric longitudinal data analysis. The method utilizes a local log‐linear approximation for the variance function and adopts a generalized estimating equation approach to account for within subject correlations. We show theoretically and empirically that our method outperforms estimators using working independence that ignores the correlations. The Canadian Journal of Statistics 39: 656–670; 2011. © 2011 Statistical Society of Canada     

Noninformative priors for linear combinations of normal means with unequal variances

For normal populations with unequal variances, we develop matching priors and reference priors for a linear combination of the means. Here, we find three second-order matching priors: a highest posterior density (HPD) matching prior, a cumulative distribution function (CDF) matching prior, and a likelihood ratio (LR) matching prior. Furthermore, we show that the reference priors are all first-order matching priors, but that they do not satisfy the second-order matching criterion that establishes the symmetry and the unimodality of the posterior under the developed priors. The results of a simulation indicate that the second-order matching prior outperforms the reference priors in terms of matching the target coverage probabilities, in a frequentist sense. Finally, we compare the Bayesian credible intervals based on the developed priors with the confidence intervals derived from real data.     

中等职业教育对厦门经济发展影响的实证研究

分析厦门经济特区成立以来中等职业教育与经济发展的关系，研究证明：中职的发展与第三产业的相关性最高；中职招生波动滞后于经济波动，而人才培养的周期性使得中职的毕业生在数量和质量上与经济的差距难以避免。中职应重点预测第三产业的发展趋势，超前培养技术人才，主动参与产业结构的优化升级，国家也应该注重灵活自主的社会职业培训机构。随着人们日益追求高层次的教育和初中阶段适龄青年的减少，中职即将进入逐步下降阶段，应该注重可持续发展，为将来部分条件好的中职院校升格高职院校预留条件。     

基于Solid works蜗轮蜗杆三维建模的研究

在Solid works环境下进行了蜗轮蜗杆三维设计研究,这对类似复杂曲面的零件设计具有实际意义。     

信息技术在中小学体育工作中应用的实效性评价研究

随着基础教育改革的深入，信息技术在各科教学中的应用越来越普遍，体育也不例外。为了探讨和了解信息技术在中小学体育中应用的实际效果，本研究从信息技术应用于中小学体育的实效性内涵入手，对信息技术应用于中小学体育的实效性评价目标、原则、方法以及在实践中应处理的关键问题进行初步探讨，以期促进信息技术在中小学体育中的实际应用。     

Do people think about absolute or relative price differences when choosing between substitute goods?

The article presents experimental evidence that shows that people often consider relative price differences in addition to absolute differences when choosing between substitute goods. Because the choice between substitute goods is a very common one, this is an important finding. The experiment uses scenarios in various consumption categories: hotel rooms, flights, and books. Subjects were either students or participants in an economics conference. The data allow to reject the hypothesis that people think only about relative price differences in favor of the hypothesis that people think about both relative and absolute price differences. Whether the price given to the subjects is that of the high-quality good or of the low-quality good makes a large difference, a result that is related to the endowment effect and the status quo bias. Implications of the results for business strategy and other areas are also discussed.