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.     

国际科研众筹项目的特征描述、主题分析及属性对比:基于Experiment平台的发现

[目的/意义]为了深入了解科研众筹平台中的项目情况,本文对科研众筹项目的基本特征、研究主题和不同类型科研众筹项目的属性对比进行研究。[研究设计/方法]首先对科研众筹的起源、价值和运作模式进行了梳理;随后爬取了科研众筹平台Experiment的项目信息,并对该平台中科研项目的发起者、背书者、项目记录、所属学科、资助情况等进行特征描述;基于LDA模型对科研众筹项目主题进一步细化,并对不同资金筹集和不同主题分类情况下的科研众筹项目的属性差异进行比较分析。[结论/发现]科研众筹主题主要集中在生物学和生态学两个领域,不同资金筹集达成情况的科研众筹项目在项目背书者数量、信息记录次数和讨论次数上具有显著差异;不同主题的科研众筹项目在其讨论次数上具有显著差异。同时,是否提供视频和是否参与资助挑战在不同资金筹集达成情况和不同主题的科研众筹项目上均具有显著差异。[创新/价值]深入分析了科研众筹平台中项目主题及属性对比情况,对科研众筹平台优化信息审核机制、社交机制和信息展示机制具有一定的参考价值。     

Children’s Drawing,Self Expression,Identity and the Imagination

Directions, Volume 18 Number 1 [1] suggests that postmodern theory is beginning to have a significant effect upon educational practice. Atkinson [2] has directed attention towards the effects of both the construction of the subject and the real within art teaching. Much postmodern theory challenges the unitary, pre–existing subject. This paper will argue that the persistence of an ideology of self–expression which asserts that all representation is in connection with (should be read in relation to) a singular, pure, pre–existing self acts to limit our understandings of the complexity of children’s representations and is in conflict with many contemporary positions. Research has centred on the development of ‘out of school’ sketchbooks. Large sketchbooks were given out to nursery and reception children paired with older siblings in primary education. Possible drawing activities and interests were discussed and children were left to develop the sketchbooks at home. Two weeks later (including a half term holiday) the children were interviewed in relation to the drawings developed. The drawings have been considered in relation to contemporary approaches to self and identity. The conclusions of this paper revolve around the possibilities of reading children’s drawing in relation to self and identity through the interaction of social context, discursive practice and agency in a manner which is suggested by Ricouer’s formulation of the social imaginary. Additionally, the substitution of tenacious notions of expression with concepts of agency and contingency grounded in the characteristics of ‘citationality’, articulation and narrative are suggested as a basis for developing the educational potential of drawing.     

Children's conceptions of probability — A psychological and pedagogical review

This paper identifies a number of key questions concerning children's understanding of probability. A selection of psychological and pedagogical research studies is evaluated. Attention is drawn to the various definitions of probability assumed by their authors, indicating the relevance of these to an understanding and synthesis of the reported findings. The possibility of basing relevant classroom practice on subjective rather than theoretical concepts of probability is discussed.     

试论中国国民党“政党领军”模式的确立及共发展演变

政党领军模式的出现反映了以孙中山为首的革命党人欲建立一支与旧军队相区别的新式武装的情绪，也反映了党在军队中影响的现实。它为整合国家军政关系、改革军制、建设现代武装力量、消除地方割据：完成政治统一诸多问题发挥了重大的历史性作用。其发展演变更为我们了解近代中国军政关系的曲折演变提供了器物基础。     

Outcome status of students with learning disabilities at ages 21 and 24

This study investigated whether the presence of learning disabilities (LD) at age 10 was related to later schooling, employment, income, receipt of public aid, involvement in crime, and feeling of victimization at ages 21 and 24. Confidential self-report data were collected in a prospective, longitudinal panel study from a sample of 571 students, of whom 60 (10.5%) were children with LD. After controlling for gender, ethnicity, and socioeconomic status, the following results were obtained: The highest postsecondary school attainment for young adults with LD was not significantly different from that of their peers without LD, both at age 21 and age 24. The rate of employment and amount of earned income of young adults with LD were not significantly lower than those of their peers without LD both at age 21 and age 24. Young adults with LD were not significantly different from their peers without LD at age 21 and age 24 with respect to having children, but young adults with LD received significantly more public aid (such as food stamps, supplemental security income, and unemployment compensation) at age 21 but not at age 24. Young adults with LD were not significantly different from their peers without LD in committing crimes or feeling victimized at age 21 and age 24.