优秀拳击运动员教学实战与比赛后血乳酸的调查与分析

为掌握拳击比赛和教学实战的血乳酸情况,以我国备战世锦赛的24名优秀拳击运动员作为研究对象,在比赛和教学实战后检测血乳酸浓度,其结果显示拳击比赛的强度较大,比赛对运动员无氧能力要求高;运动员对于教学实战的重视程度以及比赛强度没有达到比赛的要求,教学实战的训练效果没有完全达到预期的目的;大级别拳击运动员专项耐酸能力训练方法及教学实战的质量有待改进与提高.     

连二亚硫酸钠对淹水土壤中p,p'-DDT脱氯过程的影响及机理研究

在淹水培养条件下(土/水=2 g/40 mL),研究连二亚硫酸钠(200 mmol/L Na2S2O4)对p,p'-DDT在自然土和Na2S2O4还原土壤中降解历程的影响及机理.在自然土和还原土中添加Na2S2O4促进p,p'-DDT降解,2 d降解率分别为73%和79%,随后降解缓慢.p,p'-DDT在土壤中降解为p,p'-DDD和p,p'-DDE.p,p'-DDT主要被Na2S2O4降解,Na2S2O4还原土壤产生的Fe2+也有贡献.Na2S2O4与Fe2+体系对修复DDTs污染土壤有应用前景.     

孙子兵法版本流变

孙子兵法是我国现在最早的兵书,自流传至今约2500年存在多种版本。从最早的魏武帝注本,到宋朝的《武经七书》本、吉天宝撰《孙子十家注》本,再到清朝孙星衍校定的《孙子十一家注》,再加上七十年代银雀山汉墓竹简本《孙子》的出土,为《孙子兵法》的研究提供了充分的文献材料。本文简单考察《孙子兵法》版本的流变情况,以此来更好地学习和研究《孙子兵法》。     

论美国利益团体在马歇尔计划形成中的作用

马歇尔计划不只是美国政府内少数精英设计出来的,而且在相当程度上也是美国一些利益集团加以推进的结果.这些美国商业、劳工等利益团体不但通过发布声明、发表演讲支持马歇尔计划,而且还组建哈里曼委员会直接参与到该计划政策的制订中,对后来马歇尔计划的实施产生了重要影响.     

独立学院市场营销专业的发展前景分析——以中国石油大学胜利学院为例

独立学院的专业选择影响着学院的发展.中国石油大学胜利学院在权衡内外部资源条件的基础上,适时设置了市场营销专业进行重点建设,对学院实现内涵式发展具有重大意义.与周边高校相比,该专业在发展、办学、就业等方面有很强的吸引力,拥有良好的发展前景.     

A simple and effective protein folding activity suitable for large lectures

This article describes a simple and inexpensive hands-on simulation of protein folding suitable for use in large lecture classes. This activity uses a minimum of parts, tools, and skill to simulate some of the fundamental principles of protein folding. The major concepts targeted are that proteins begin as linear polypeptides and fold to three-dimensional structures, noncovalent interactions drive this folding process, and the final folded shape of a protein depends on its amino acid sequence. At the start of the activity, students are given pieces of insulated wire from which they each construct and fold their own polypeptide. This activity was evaluated in three ways. A random sample of student-generated polypeptides collected after the activity shows that most students were able to create an appropriate structure. After this activity, students (n = 154) completed an open-ended survey. Their responses showed that more than three-quarters of the students learned one or more of the core concepts being demonstrated. Finally, a follow-up survey was conducted seven weeks after the activity; responses to this survey (n = 63) showed that a similar fraction of students still retained these key concepts. This activity should be useful in large introductory-level college biology or biochemistry lectures.