Bayesian Analysis of Mixture Structural Equation Models With an Unknown Number of Components

Multivariate heterogenous data with latent variables are common in many fields such as biological, medical, behavioral, and social-psychological sciences. Mixture structural equation models are multivariate techniques used to examine heterogeneous interrelationships among latent variables. In the analysis of mixture models, determination of the number of mixture components is always an important and challenging issue. This article aims to develop a full Bayesian approach with the use of reversible jump Markov chain Monte Carlo method to analyze mixture structural equation models with an unknown number of components. The proposed procedure can simultaneously and efficiently select the number of mixture components and conduct parameter estimation. Simulation studies show the satisfactory empirical performance of the method. The proposed method is applied to study risk factors of osteoporotic fractures in older people.     

网络学习境脉视角下的网络教育资源建设策略

该文以"网络学习境脉"的概念模型为基础,分别从该模型的三个构成要素:技术境脉、知识境脉与社会境脉角度出发,借鉴了无尺度网络理论,提出了网络教育资源建设的三个策略,为促进网络教育资源的建设提供了参考。     

课堂教学情境下学科高阶思维的结构与发展规律——以语文学科为例

高阶思维发展“沉浸”在不同学科课堂教学情境中,呈现出具有学科思维特点和学科活动特征的内在结构与发展规律。文章以语文学科为例,基于思维结构、高阶思维结构等基本理论,结合对学科思维的深入剖析,建立了认知要素与情感要素协同作用、思维过程与思维品质动态发展的学科高阶思维结构模型;进而以模型为理论框架对学科课堂教学视频进行质性分析,挖掘课堂情境中高阶思维活动发生与发展的表现与特征,构建了以复杂问题解决过程为主线、体现思维活动阶段性特征、高阶思维内在要素协同发挥作用、高阶思维外在品质不同程度提升的学科高阶思维发展规律模型。以期为探析学科高阶思维结构与发展规律提供一种思路与方法,为高阶思维发展取向的学科课堂教学设计与实施提供理论依据。     

English language learners and kindergarten entry age: Achievement and social-emotional effects

In evaluating the role of kindergarten entry age, previous researchers have not examined the entry-age effects for English language learners (ELL). Additionally, little work has assessed the role of entry age on both achievement and social-emotional outcomes. This study is the first to do both simultaneously. The authors used data from a longitudinal study that followed a national sample of U.S. students from kindergarten through Grade 5. Relying on variation in children's birth dates and in states' kindergarten entrance age cutoffs, the authors estimated how differences in the age at which children enroll in kindergarten are related to their achievement and social-emotional outcomes. Our results show that enrolling in kindergarten as an older entrant is associated with significantly higher achievement and social-behavioral outcomes during the early elementary school years for ELL students, but that these effects largely disappear by the end of elementary school. Policy implications are addressed.     

四元六次对称多项式不等式探讨

对四元六次对称多项式不等式的分拆进行了初步探讨；证明了若干拆分基不等式和含参不等式；最后提出了若干问题。     

离散大系统关于部分变元指数稳定性

本文利用向量Л(?)ПУНОВ函数讨论了一类离散大系统关于部分变元的指数稳定和关联指数稳定。获得了一些新的代数判据改进了文[ ]等的工作。     

中诗英译难点探析

英汉两门语言文字类型不同，表达各异，译时需从整体风格出发注重语境分析，以保存原作艺术魅力，并注意关键词与语意场，再现语意内容和形式风格。语境分析是诗歌翻译的实质所在。     

International comparative studies in teaching and teacher education

This review of eight papers published in Teaching and Teacher Education over the past twenty years shows how the profession has been impacted by the forces of globalisation. The impact varies in different contexts, according to local factors. The review looks at papers that use explicit international comparisons as a means to bring local contextual characteristics into sharp relief, and discusses the values and pitfalls of this approach. The review concludes by suggesting a possible future agenda for international comparisons, one that seeks answers to the domestic challenges of the Millennium Development Goals and Education for All by looking for solutions overseas. However, international appropriation needs to remain highly sensitive to the cultural context of implementation.     

微积分学L’Hospital法则的推广研究

本文将一元函数L’Hospital法则进行研究推广,在柯西中值定理的基础上建立多元函数L’Hospital法则,使L’Hospital法则的应用更广泛。     

Cognitive,Affective, Personality,and Demographic Predictors of Foreign-Language Achievement

Abstract

The ability of cognitive, affective, personality, and demographic variables to predict second-language acquisition among college students was investigated. An all possible subsets regression analysis was used to compare the proportion of variance in foreign-language achievement explained by each variable. The analysis revealed that variables from each of the 4 domains were important predictors of foreign-language achievement. Overall, academic achievement, as measured by GPA average, was the best predictor, explaining 11.5% of the variance in foreign-language achievement. Foreign-language anxiety, the next best predictor, explained 10.5% of the variance. The educational implications of these findings for understanding foreign-language achievement are discussed, along with suggestions for future research.