超顺磁性Fe2O3较Fe3O4用于磁共振胃肠造影剂的优劣研究

用超顺磁性氧化铁制备磁共振造影剂的报道较多,其中的磁粒均为Fe3O4。本文提出了用Fe2O3的可行性,并根据超顺磁性理论推导出两种微粒显示超顺磁现象的临界尺寸理论值分别为24.8nm、31.6 nm,在1.5T磁共振磁场中的临界值为7.1 nm、11.1 nm;根据磁学理论,分析了磁共振造影剂稳定的机理;推导出在磁共振磁场中,两者在造影剂中稳定悬浮的极限尺寸为13.3 nm、14 nm。得出在造影剂中,两者既能稳定悬浮又具有超顺磁性的临界尺寸为7.1 nm、11.1 nm的结论。同时分析了两者用做磁共振胃肠造影剂的优劣点。     

CET4题型设计模式研究——基于任务特征理论的大学英语测试实证探索

任务型语言测试观为大学英语测试（CET）提供了新的理论基础。在Bachman与Palmer的测试任务五特征基础上,创设了新题型设计基本模式,并依据该模式设计新题型对CET4测试进行了初步探索。信度和效度实证检验的结果表明,新题型组的均值虽因主观性试题量的增加而略低于旧题型组,但两者间并无显著性差异。而且新题型还呈现出同期效度值比旧题型高的态势：同时其信度系数也较高且具有显著的统计学意义。     

美国RIP和4-H科学探究模型评析及启示

新一轮基础教育课程改革对教师教学方式的多样化提出了要求,其中特别强调了科学探究教学,这给我国科学教育工作者及广大教师提出了一个崭新课题。本文介绍了RIP和4-H两种美国常用的科学探究模型,希望能给我国科学探究教学带来一些启示。     

锂离子电池正极材料LiMn1.5Ni0.5O4电化学性能研究

以LiMn1.5Ni0.5O4为锂离子电池备选的正极活性物质,通过充放电试验、X射线衍射试验、循环伏安试验等,研究其作为正极材料的电化学性能。     

传统美德与北京四中的德育

北京四中以植根于传统文化的中华传统美德为德育核心，传统文化、传统美德、四中人的精神是紧密关联、三位一体的。北京四中以传统文化、传统美德为依托，构建了立体多维的德育网络。     

Mathematics: a female,male or gender‐neutral domain? A study of attitudes among students at secondary level

The aim of the current study is to investigate whether Swedish secondary school students perceive mathematics as a female, male or gender‐neutral domain. A sample of 1300 students in two age groups, 15‐ and 17‐ years, answered a questionnaire and about 50 students participated in interviews. The main part of the inquiry form consists of Who and mathematics, an attitude scale recently developed by other researchers. The results are analysed with respect to gender, school year and study programme. Gendered attitudes were found among considerable minorities. There is a marked tendency to view mathematics as a symbolically male domain: positive aspects are associated with boys and negative aspects perceived as more female. Older students hold more strongly gendered views than younger. Boys in the science programme have the strongest beliefs of mathematics as a male domain.     

Leading professional learning in an Australian secondary school through school‐university partnerships

As the limitations of one‐off and disconnected professional learning programs for teachers are recognised, there is widespread interest in building learning communities and professional learning teams within schools. When considering how to build local learning communities, school and university partnerships are seen as offering rich possibilities for transformative professional action. Set in the context of the international agenda of “Education For All” (UNESCO, 2005 UNESCO. (2005). Education for all: Global monitoring project. Retrieved January 8, 2007, from http://portal.unesco.org/education/en/ev.php‐URL_ID=36004&URL_DO=DO_TOPIC&URL_SECTION=201.html (http://portal.unesco.org/education/en/ev.php-URL_ID=36004&URL_DO=DO_TOPIC&URL_SECTION=201.html)  [Google Scholar]) a model of sustained on‐going professional learning, developed in one large secondary school in Australia, is analysed. The social practices that generate action and participation for partnership members are then scrutinised for the legitimacy of school‐university partnerships and the contribution to enhancing teacher learning.     

微波辐射相转移催化合成对羟基苯甲酸杉酯的研究

以对羟基苯甲酸和氯化苄等为原料,以十六烷基溴化铵为相转移催化剂合成对羟基苯甲酸苄酯。通过实验考察了催化剂用量及物料配比等因素对酯化反应的影响。结果表明:微波辐射功率350W,辐射时间3min,n(对羟基苯甲酸)∶n(氯化苄)=1∶2,n(正十六烷基三甲基溴化铵)∶n(对羟基苯甲酸)=0.025,产率可达96.7%。     

UK higher education viewed through the marketization and marketing lenses

This paper uses the Economic Market mechanisms and the 4P Marketing Mix as lenses to review the context of UK higher education (HE) and to explore the relationship between the market and marketing disciplines and practice. Four Economic Market mechanisms – autonomy, competition, price and information – are contrasted with the four Ps of marketing: product, price, place and promotion. This paper demonstrates how market forces influence HE institutions and, in contrast, how HE institutions shape the environment via marketing practice. Knowing how one discipline relates to another is crucial for those who strive to understand the context of HE.     

Urban teachers’ perceptions of inclusion of migrant children in the Chinese educational institution: a comparative study

Recently China has been undergoing an unprecedented urbanisation process which has resulted in millions of rural families living in urban areas. As part of a study of Chinese migrant children's educational experiences, surveys and interviews were conducted with primary school teachers in a metropolitan city in East China. The objectives of this study were to describe teachers’ perceptions of migrant children's education in both migrant schools and in public schools, and to investigate differences in their beliefs between school types. Results found that urban teachers’ perceptions of educational inclusion of migrant students were slightly negative in general. However, teachers in public schools showed significantly more positive attitudes to inclusion of migrant students than migrant school teachers. In the light of these findings, the paper concludes with implications for practice and policy for education of migrant children in China.