合成低碳醇铜钴催化剂的TEM与TPR表征

用电子显微镜(TEM)和程序升温仪(TPR)分别对加钾(K)前后的共沉淀铜钴催化剂[m(Cu)/m(Co)=0.358g]进行了TEM和TPR表征.从TPR图上发现,催化剂加K后,催化剂的还原性受到抑制,导致加K后催化剂活性下降;另外从TEM图上得知,加钾后催化剂的粒径增大,也导致加钾后催化剂活性下降,因此催化剂中钾的加入量应适宜.     

Instructional Investment or Administrative Bloat: The Effects of Charter System Conversion on Resource Allocations and Staffing Patterns

Despite the growing call for local autonomy and flexibility, few scholars have examined the role of school district–level flexibility on resource allocation and staffing patterns. Leveraging the charter system law within the State of Georgia, we utilize a generalized difference-in-differences approach to estimate the impact of flexibility of system-level expenditures and staffing changes. We find evidence of increases in central office spending and staffing post-conversion to a charter system. In addition, we find evidence that local support is replaced by the state-funded supplemental funding.     

浅析英国的"素质教育"

在英国的教育中,课堂教学所体现出的内容非常广泛,它是在课堂教学高度自由化的前提下,在融洽的课堂气氛中,以先进的教学设施为辅助,在师生互动交流中达到教学目标并满足社会需求的。同时,其教育过程高度重视对学生进行社会意识和团队精神的培养。这些教育理念和教育方法为我国开展素质教育提供了值得借鉴的经验。     

四元数空间形式中混合型全拟脐QR-子流形

考查四元数空间形式中混合型全拟脐QR-子流形并研究了四元数空间形式中具有某种条件下的混合型伪脐QR-子流形.进而研究了四元数K(a)ehler流形的QR-子流形,给出了一些有趣的结果.     

英国高校办学模式及思考

悠久的历史、鲜明的特色、深厚的基础、扎实的专业知识、强有力的实践技能锻炼和良好的社会声誉是英国高校的办学魅力所在,我们应该结合国情,借鉴国外的先进经验,优化我国高等教育的办学模式。     

三种贝母核型的比较研究

The present paper deals with a comparative karyotypic study of three species in Fri- tillaria-F. thuncergii Miq., F. anhuiensis S.  . Chen et S. F. Yin and F. hupehensis Hsiao et K. C. Hsia.  The karyotype of F. anhuiensis S. C. Chen et S. F. Yin is first reported.       The karyotypes of the three species of Fritillaria are rather similar, all with K(2n)=24= 2m+2sm+12t+4st+4m (SAT), showing a close interspecific relationship.  They all have two pairs of st chromosomes, one of which is the third chromosome in all the three species studied, but the other is the seventh in F. thunbergii Miq, the eighth in F. anhuiensis S. C. Chen et S. F. Yin, and the fifth in F. hupehensis Hsiao et K. C. Hsia.  It tells us that there are some differences in their karyotypes.  All of the three species possess two pairs of satellite chromosomes with the satellites located on the long arms. A heterochromatic zone is found sometimes on long arms of No. IX chromosome in each species of Fritillaria and on one of No. I chromosomes in both F. thun- bergii Miq. and F. anhuiensis S. C. Chen et S. F. Yin, a chromosome polymorphism occurring between populations of Fritillaria. In addition, three B chromosomes are always found in most root-tip cells of F. hupehensis Hsiao et K. C. Hsiao.     

K-Means聚类的多种距离计算方法的文本实验比较

针对文本类型数据的分类进行研究,用VSM模型和TF IDF技术对文本文件进行了数据样本抽取加权,得到文本相似度矩阵;采用不同样本距离计算方法和K-Means算法对数据进行了聚类实验,获得聚类结果并进行了分析和总结;基于实验结论,研究了不同距离计算方法之间的区别以及适用的数据类型。     

英美澳远程教育质量评估体系研究及启示

在高等教育大众化及教育现代化的背景下,远程教育质量已经引起世界各国的高度重视。不同国家或机构依据自身国情及教育环境,在不同的价值取向和质量观指导下,形成各自的远程教育质量评估体系。近十年我国远程教育质量评估文献表明：从外部评估角度来看,英国、美国、澳大利亚的现代远程教育质量评估体系在质量观、评估标准、执行者、过程及效果反馈等方面有各自的特征,且具有较好的实施效果。我国在建立远程教育质量评估体系时,可以在结合自身国情的基础上,借鉴他国的有益措施。