Supportive classrooms for Latino English language learners: Grit,ELL status,and the classroom context

Students' academic achievement is the result of the interplay between person-level and contextual factors (R. R: Greene, 2014; D. E. Hunt, 1975). Students perform better when classroom characteristics support their characteristics. The authors examine whether student perceptions of two classroom characteristics (care and control) fit with two Latino student characteristics (English language learner status and grit) in relation to their academic achievement. Using a sample of fourth- and fifth-grade Latino students from the Measures of Effective Teaching dataset (n = 3,272), the authors conducted a series of nested regression models with two- and three-way interactions between student characteristics and student perceptions of classroom characteristics. Findings revealed that grit is most strongly associated with Latino English language learners’ English/language arts achievement when students perceived that teachers used high levels of care and control. We conclude with implications for practitioners.     

跳远运动空中技术分析

运用动态力学理论，建立单腿摆动力学模型和动力学方程，运算推导出人体在腾空阶段由于合理的肢体摆动水平速度出现增量，因而证明人体重心在跳远腾空中不是单质体空间运动轨迹，提出了由于肢体后直、前屈，速度快慢、力量大小的摆动而引起人体速度和位移变化的“动态抛物线”理论；并用加速传感器测试系统测试运动肢体摆动参数及身体在空中的速度变化，对“动态抛物线”理论进行了验证。这与传统的“起跳腾空后，身体重心的运动轨迹在没有外力作用的情况下是不会改变的”理论迥然不同。利用这种理论，可以规范和完善跳远空中技术，提高教学质量和运动成绩。     

辛亥鼎革士子的政治选择及其对革命的认知——以云南绅耆为例

辛亥鼎革,清季士子大部分以积极的姿态融入民国,即使自况为＂遗老＂、＂遗民＂者,其身份界定亦大有讨论余地,其中曲折甚有探讨之处。以云南绅耆在鼎革之际的政治选择的过程及其对辛亥革命的认知为例,我们可以看到清朝与民国之间存在明显的延续性,民国建立的特殊方式,为清季士子接受和进入民国创造了一个更为宽松的环境。     

物理学高层观念的衍变与理论框架的层次性

物理学理论框架具有严格的层次性,其逻辑结构为：原理——定律——定理．通过分析每一层次的称谓、含义、属性,强调了作为高层观念的原理是随着物理学的发展而不断衍变的,因而认为,物理学的“第一性原理”具有灵活性和阶段性．     

危害人类罪和武装冲突要件的相关性分析

危害人类罪是一个比较有争议的罪名,尤其关于危害人类罪和武装冲突之间的关系,即危害人类罪到底要不要武装冲突要件?本文通过对危害人类罪的发展历史的纵向考察和对《罗马规约》的横向分析,认为危害人类罪的武装冲突要件的观点已经被历史和现今的国际实践所摒弃,故本文认为我国对危害人类罪的武装冲突要件的保留已经不合时宜,我国应当尽快撤销这种保留,为加入《罗马规约》迈开第一步。     

Using model-based scaffolds to support students solving context-based chemistry problems

ABSTRACT

Context-based learning aims to make learning more meaningful by raising meaningful problems. However, these types of problems often require reflection and thinking processes that are more complex and thus more difficult for students, putting high demands on students’ problem-solving capabilities. In this paper, students’ approaches when solving context-based chemistry problems and effects of systematic scaffolds are analysed based on the Model of Hierarchical Complexity. Most answers were initially assigned to the lowest level of the model; higher levels were reached without scaffolds only by few students and by most students with scaffolds. The results are discussed with regard to practical implications in terms of how teachers could make use of context-based tasks and aligned scaffolds to help students in this activity.     

对组距数列计算平均指标的方法探讨

运用组距数列组中值加权算术平均法计算平均指标比较麻烦，也容易出错；我们可以通过利用组距数列的下限值或上限值来求平均指标的方法加以避免。     

基于非对称相似关系的粗集改进模型

改进了基于非对称相似关系的粗集的上、下近似的定义,并从理论上证明了新定义的上、下近似比原来的更合理,并进一步用一个算例来验证。     

方程(axm+1)/(ax+1)=yn的正整数解

设a，m是大于1的正整数．本文证明了：当m〉2时，方程（ax^m＋1）／（ax＋1）=y^n仅有有限多组解（x，y，n）适合min（x,y,n）〉1，而且这些解都满足y^n≤x^（m-）≤a^（m^2-3m＋2）。     

积分不等性的几种类型应用

不等式证明和极限求解问题是高等数学命题的热点和难点,探讨如何应用积分不等性解决这两类问题,并列举出了实例及求解过程。