Heteroskedastic linear regression model with compositional response and covariates

Compositional data are known as a sort of complex multidimensional data with the feature that reflect the relative information rather than absolute information. There are a variety of models for regression analysis with compositional variables. Similar to the traditional regression analysis, the heteroskedasticity still exists in these models. However, the existing heteroskedastic regression analysis methods cannot apply in these models with compositional error term. In this paper, we mainly study the heteroskedastic linear regression model with compositional response and covariates. The parameter estimator is obtained through weighted least squares method. For the hypothesis test of parameter, the test statistic is based on the original least squares estimator and corresponding heteroskedasticity-consistent covariance matrix estimator. When the proposed method is applied to both simulation and real example, we use the original least squares method as a comparison during the whole process. The results implicate the model's practicality and effectiveness in regression analysis with heteroskedasticity.     

关于丢番图方程(n-1)_∑~(k=0)[1-(80s+72)k]~r=[1+(80s+72)~n]~7

本文证明了：当n，r为正整数，s为非负整数，丢番图方程无整数解。     

钌多氢化物的均相CO加氢反应催化性能研究及原位红外表征

用钌多氧化物作为均相ＣＯ加氢催化剂前体，在较低的温度和压力下进行釜式ＣＯ加氢反应，主要产物为低碳烷烃。实验结果表明，反应温度，时间，合成气比（Ｈ２／ＣＯ）和溶剂对ＣＯ转化率以及产物分布均产生影响。根据原位红外对反应的监测结果，提出了钌多氢化物均相ＣＯ加氢反应模式。     

A discrete analog of Gumbel distribution: properties,parameter estimation and applications

A discrete version of the Gumbel distribution (Type-I Extreme Value distribution) has been derived by using the general approach of discretization of a continuous distribution. Important distributional and reliability properties have been explored. It has been shown that depending on the choice of parameters the proposed distribution can be positively or negatively skewed; possess long-tail(s). Log-concavity of the distribution and consequent results have been established. Estimation of parameters by method of maximum likelihood, method of moments, and method of proportions has been discussed. A method of checking model adequacy and regression type estimation based on empirical survival function has also been examined. A simulation study has been carried out to compare and check the efficacy of the three methods of estimations. The distribution has been applied to model three real count data sets from diverse application area namely, survival times in number of days, maximum annual floods data from Brazil and goal differences in English premier league, and the results show the relevance of the proposed distribution.     

经济法本质论

综合我国学者对经济法本质的研究成果 ,特别对较有影响的“干预主义”和“协调主义”进行如下评述 :协调主义忽视矛盾分析法 ,把各种矛盾或矛盾两方面平均看待 ,貌似全面 ,但否认重点 ,是“均衡论”的表现。“干预主义”对经济法本质的认识过于细划 ,不利于经济法学界统一认识。通过对经济法本质的辩证思维法分析和矛盾论分析 ,应将经济法的本质与经济法概念、经济法调整对象等其他基本理论的研究范畴加以区分。经济法的本质只能是“国家干预经济之法”。     

在华外籍就业人员的社会适应

本文通过对30位在华外籍就业人员的深度访谈,以其作为城市强势外来者的视角,来考察这一人群在中国城市的工作生活状况,揭示他们的文化认知及社会适应的特点。最后,笔者提出了有关强势外来者社会适应的若干命题。       

宁夏城市回族通婚现状调查研究——以银川、吴忠、灵武为例

尽管族际婚已成为研究民族关系、民族过程的不可回避的话题 ,但由于宗教信仰、生活习惯等问题的敏感性使西北回族的族际婚在大多数家庭中仍不被认可 ,而族际婚的上升仍是西北回族群众必须面对的现实问题之一。回族族内婚在现实中发生了哪些变化 ,变化的原因和结果如何 ,这些问题是关系到一个民族的文化的未来走向、民族的现代化以及民族间的相互关系和融合的趋势等重大社会问题。带着这些问题 ,我来到中国惟一的回族自治区———宁夏 ,在 3个不同规模的城市 :银川、吴忠、灵武作了 3个月的调查 ,对回族婚姻的现状进行了考察和分析 ,以引起回族群众、回族知识分子及政府相关部门对此问题的关注与重视 ,处理好现实中的矛盾 ,为回族的社会发展和民族繁荣提供更好的环境。     

变系数齐线性方程稳定的必要条件

用等价变换和解的性质得到了变系数齐线性方程稳定的一些必要条件．     

热方程组的熄灭时间对初值的连续依赖性

利用极值原理和构造辅助函数的方法,我们证明了一类齐次二维热方程组解的熄灭时间连续依赖于初值.