Simple Preparation of Spherical Activated Carbon with Mesoporous Structure from Phenolic Resol and Associated Catalytic Performance in Isobutane Dehydrogenation

This study provides a detailed report on the synthesis of spherical activated carbon with mesoporous structure using a soluble low molecular weight phenolic resol precursor through an ammonium alginate assisted sol–gel method. The effects of calcinating temperature and the addition of CaCO_3 as a pore-enlarging agent on texture structure and catalytic performance in isobutane dehydrogenation to isobutene were investigated. Characterization of N_2 sorption,mechanical strength tests,and optical photographs confirmed that the obtained carbon materials had high mechanical strength,a good degree of sphericity,and a large surface area. Introducing CaCO_3 as a pore-enlarging agent during the preparation process promoted the formation of a mesoporous structure of carbon spheres and evidently increased the surface area and oxygen content,which can improve isobutane conversion and isobutene selectivity of these carbon spheres. The conversion of isobutane reached up to 28% for this spherical activated carbon,and the selectivity of isobutene reached up to 96%. Isobutane conversion increased with an increase in calcination temperature due to an increase in the oxygen content,whereas the selectivity of isobutene decreased due to the slight decrease in the specific surface area.     

突出"课程"要素保障教学质量——华威大学教学质量内部保障体系研究

华威大学是一所在短时间内迅速崛起的新大学,它的成功与其教学质量内部保障体系关系密切.本文在对华威大学教学质量保障体系的目标、组织构架、保障方法等进行分析的基础上,总结出其教学质量保障体系的几个突出特点:切合实际的质量目标、高效的组织结构、紧紧围绕"课程"保障教学质量的方法,并将这种突出强调"课程"要素的质量保障体系归纳为"课程型"质量保障模式.     

试论区域科技创新体系的构建与推进

文章论述了构建区域科技创新体系应遵循的基本原则,并根据相关原则及各子系统的功能和相互关系构筑了区域科技创新体系组织结构的框架模型,即认为:区域科技创新体系包括两个层次、六个子系统。最后提出了推进区域科技创新体系建设的一些对策措施。     

一水邻苯二甲酸钙的热分解及其脱水动力学分析

采用TG-DTA分析研究了一水邻苯二甲酸钙热分解过程,对其中的脱水过程进行了动力学计算. 由Friedman和Ozawa-Flynn-Friedman法得到脱水过程的活化能和指前因子,用Archar方法计算拟合了几种机理函数,确定了脱水过程的优化动力学参数及最佳机理模型. 脱水过程的活化能Ea为141.1576 kJ/mol,反应的机理模型为Bna,即f(α) =(1-α)n*αn.     

少儿英语教学与语言习得

语言学习和语言习得在学习效果上存在一定的差异.在少儿英语教学中发展儿童语言运用能力的关键在于教师应结合儿童认知能力的发展,从语言信息输入定位、输入输出定位、教学顺序定位、情感因素过滤方面来创设语言习得环境.     

试论《商君书》关于选任官吏的思想

《商君书》蕴含有丰富的选官思想，对于官吏的起源、地位、作用、选拔和任用以及对官吏的控制、精简等等都有阐述。它在秦国历史上产生过重要的影响，起到了积极的、进步的历史作用，在深化人事体制改革的今天，为了记取历史的经验和教训，我们仍有必要对此进行研究和总结。     

论音乐教学中的审美心理因素

音乐是听觉的艺术,它通过特殊的音乐语言-旋律,振撼人们的心灵,使人产生愉悦,激发想象,产生情感,获得美的享受.教师要懂得审美心理因素在教学中的作用,并将它贯穿、融汇在音乐教学中,方能提高学生的审美情趣和音乐素养.     

儒家恕道与中国古代法律文化

儒家恕道与中国古代法律化传统有着内在的不可分割的密切联系，使中国传统法律化表现出鲜明独特的公法化的个性特征。本从恕道的渊源、内涵及法化品性入手，阐述了其对于中国古代法律化的影响，并剖析了恕道、法律化传统与现实的关系。     

影响高校毕业生就业的社会资本因素分析

社会资本是近年来学术界研究较多的一个问题。本文在对社会资本及大学生就业相关文献进行梳理的基础上,利用北京大学教育学院"高等教育规模扩展与劳动力市场"课题组于2005年6月对全国34所高校调查的数据,对大学生社会资本状况,社会资本对大学生毕业去向、就业落实率、起薪及工作满意度的影响,进行了实证分析。本文的主要研究结果如下:(1)与来自社会经济地位较高的家庭的学生相比,来自社会弱势家庭的学生在家庭社会资本与个人社会资本上都比较缺乏;(2)大学生毕业选择就业或升学时,家庭社会交往广泛度对升学选择产生显著的正面影响,而个人社会交往广泛度对就业产生了显著的正面影响;(3)社会资本与大学毕业生的就业落实、起薪、工作满意度存在着显著的正面影响;(4)社会资本对大专生和本科生就业落实率有较为显著的正的影响,但是对硕士和博士的就业落实率没有显著影响。     

Forming shared inquiry structures to support knowledge building in a grade 5 community

This study explores the reflective processes by which a grade 5 science community co-constructed shared inquiry structures to focus and guide its inquiry about human body systems over a school year supported by a collaborative online environment. The co-constructed structures included a list of collective wondering areas as the shared focus of inquiry and models of the inquiry process in the form of “research cycle.” Qualitative analyses of field notes, classroom videos, student notebooks and interviews elaborate the evolution of the inquiry areas and the “research cycle” model as well as students’ adaptive use of the structures to guide deeper inquiry. Content analyses of students’ individual research questions and collaborative online discourse indicate that students used the structures to develop more advanced inquiry and make productive contributions. The results contribute to elaborating a reflective structuration approach to co-organizing and sustaining long-term, open-ended inquiry in knowledge building communities.