微波辐射下猪去氧胆酸甲酯化反应     

吴同  王健 《宜宾学院学报》2004,4(6):179-180

研究了微波辐射下猪去氧胆酸的甲酯化反应 ,通过正交实验设计 ,考察了甲醇用量、加热时间以及催化剂用量对猪去氧胆酸酯化反应产率的影响。考察了催化剂的类型对产率的影响。采用高效液相色谱进行转化率监测 ,使结果更加可靠。与常规加热法相比 ,采用微波辐射加热法 ,反应时间大大缩短且产率有所提高  相似文献   

影响藏族双语儿童学习的社会文化心理机制研究   总被引：3，自引：0，他引：3  

邢强 《民族教育研究》2001,12(4):35-40

在化资本理论、社会资本理论、资源稀释假设等理论的指导下，结合多次赴甘南藏族地区实地调查研究，编写出《化背景调查问卷》，对影响藏族双语儿童学业成绩的各种因素进行了研究，构建了学校、社区、家庭因素与双语儿童学业成绩的关系模型。研究结果显示：社区背景良好，家庭投入越多，父母教育期望越高，父母学习辅导行为越好，越有利于提升儿童的学业成绩。  相似文献   

The Bookmark Standard-Setting Method: A Literature Review   总被引：1，自引：0，他引：1  

Ana Karantonis  Stephen G. Sireci 《Educational Measurement》2006,25(1):4-12

The Bookmark method for setting standards on educational tests is currently one of the most popular standard-setting methods. However, research to support the method is scarce. In this report, we review the published and unpublished literature on this method as well as some seminal work in the area of evaluating standard-setting studies. Our review highlights both strengths and limitations of the method. Strengths include its wide acceptance and panelist confidence in the method. Limitations include a potential bias to produce lower-than-intended standards and problems in selecting the most appropriate response probability value for ordering the items presented to panelists. It is clear that more research on this method is needed to support its wide use. Several areas for future research to better understand the validity of the Bookmark method for setting standards on educational tests are presented.  相似文献   

Examining the impact of prior academic achievement on moral reasoning development among college students: A growth curve analysis     

Roisin P. Corcoran  Joanne O’Flaherty 《Journal of moral education》2016,45(4):433-448

Moral reasoning is concerned with making decisions regarding the appropriate course of action in particular situations and has been highlighted as a critical factor that may facilitate (or impede) the effectiveness of educational programs in promoting positive outcomes. This study examined the trajectories of moral reasoning as measured by the Defining Issues Test (DIT2) for college students and to what extent there are intra-individual (within student) and inter-individual (between student) changes in moral reasoning during this developmental period. The results suggest that moral reasoning was best represented by a linear increase on the mean level and non-signi?cant variability across students. The relationship between moral reasoning and students’ prior academic attainment was also examined.  相似文献   

高等专科学校英语应用能力考试问题摭析   总被引：2，自引：0，他引：2  

吴文华 《绥化学院学报》2002,22(1):72-75

本文通过对高等专科学校英语应用能力考虑的效度、信度、区分性、实用性和对教学的反拨作用的陈述与分析，使广大教师在大学英语教学中，处理好测试与教学的关系，重视应用能力的培养。  相似文献   

大学生学习成绩与学习时间的相关性研究   总被引：1，自引：0，他引：1  

李光海  崔群法 《安阳师范学院学报》2004,(2):135-137

对72名大三学生就学习成绩与学习时间的相关性进行了跟踪研究,结果表明:学习时间与学习成绩从总体上分析无显著相关,但较高的学业成绩必须有一定量的学习时间来做保证;学习时间的有无规律是决定学业成绩的重要因素;大学生学习时间上存在性别差异.  相似文献   

The Draw-a-Scientist Test in an African context: comparing students’ (stereotypical) images of scientists across university faculties     

Corlia Meyer  Marina Joubert 《Research in Science & Technological Education》2019,37(1):1-14

Background: People’s perceptions of scientists have repeatedly been investigated using the Draw-a-Scientist Test (DAST). The test is used to identify people’s (stereotypical) images of scientists, which might affect attitudes towards science and science-related career choices.

Purpose: The current study has two goals. (1) Applying the DAST at a university in South Africa, the study will add to the existing research literature through its Southern African context. (2) The study will also look more closely at the link between (stereotypical) images of scientists and science-related career choices.

Sample: The DAST was applied to first-year students (n = 445) across different faculties at a South African university. If the assumption that young people’s perceptions of scientists influence their career choice is correct, one would expect differences in the drawings made by students who have opted for different fields of study.

Design and methods: The DAST was administered during orientation week of the first-year students in January 2017. Students were provided with a prepared blank sheet of paper and asked to draw a scientist and to fill in further information on the back of the paper. A content analysis applying the DAST checklist was used to analyse the images.

Results: The findings show that South African students use about four stereotypical indicators when drawing a scientist, and social science students drew stereotypical attributes more frequently when compared to students from other faculties. A typical scientist – as depicted in this study – is a man of uncertain age, who wears eyeglasses and a lab coat, and is surrounded by laboratory equipment.

Conclusions: Findings are largely in line with the international research literature. To challenge gender stereotypes, more contact between students and female role models might be essential. If (stereotypical) images really affect science-related career choices deserves further attention in future research studies.  相似文献   

信息熵在多项选择题质量分析中的应用     

杜鹏东  孙涛  田振清 《现代教育技术》2006,16(3):36-39

多项选择题是各种测试中使用的较为广泛的题型之一,施测后对题目各选项的有效性做出判断可为评价测试质量提供重要参考依据。本文由分析多项选择问题的信息熵入手,给出多项选择题等价选法个数d的计算公式。同时,对多项选择题之间的质量比较问题,给出了使用相对熵的比较方法。  相似文献   

网上考试系统的设计与实现   总被引：1，自引：0，他引：1  

张瑛  黄英杰 《淮南职业技术学院学报》2003,3(4):97-100

考试系统是网上学习环境的重要组成部分。介绍计算机化自适应考试(Computerize Adaptive Test)的基本理论依据和实施过程，构建了设计题库的数据模型并提出一个基于Web的自适应考试系统框架结构，分别阐述了检索编辑模块、成绩管理模块、组卷模块、统计分析模块、辅助模块、试卷输出处理模块等考试系统六大模块的开发，特别是手动组卷模块功能的设计和实现。  相似文献   

谈语言测试的信度     

申莲 《新疆职业大学学报》2006,14(2):30-33

信度在语言测试中非常重要，对于广大语言教师来说，重要的是从一开始就认识到不同因素对信度的影响，因为很多教师倾向于认为测试是绝对可靠的测量工具，却认识不到语言测试只能是一种间接测试，即使是最好的测试在充当测量语言能力的工具时，也有几分不准确。本文简要介绍检验测试信度的方法及提高信度要注意的主要事项。  相似文献