Microbial desulfurization of waste latex rubber with Alicyclobacillus sp.

A microbe with desulfurizing capability, Alicyclobacillus sp., was selected to recycle waste latex rubber (WLR). The growth characteristics of the microorganism and the technical conditions in the co-culture desulfurization process were studied. The desulfurization effect of Alicyclobacillus sp. on the WLR was characterized, and the mechanism for the microbial desulfurization of WLR was tentatively explored. The results showed that adding 5% (w/v) WLR into medium had little effect on the growth of Alicyclobacillus sp. The surfactant polysorbate 80 (Tween 80) had a toxic effect on Alicyclobacillus sp., but the growth of the microbe was vigorous if the proper technique was used: the mixing of WLR with Tween 80, followed by the addition of the mixture into the culture media. With the increase of desulfurization time, the swelling value of desulfurizated waste latex rubber (DWLR) increased, but the crosslink density decreased. After co-culture desulfurization for 8–10 days, a DWLR with good desulfurization effect was obtained. The mechanical properties of natural rubber (NR)/DWLR composite improved significantly over those of NR/WLR composite. XPS and FTIR results revealed that Alicyclobacillus sp. could break the crosslinked sulfur bonds and oxidize them to sulfones groups. The increase of O element content on the surface of DWLR was confirmed by water contact angle measurements. The relationship between the crosslink density and sol fraction of DWLR with different desulfurization times agreed with the Horikx equation, an indication that the microorganisms could break the crosslinked sulfur bonds on the surface of WLR, but leaving the main chains intact.     

浅析农村中小学图书馆的现状及发展对策

中小学图书馆是图书馆事业的重要组成部分。分析了农村中小学图书馆的现状,结合具体实际提出了解决问题的对策。     

吉林省农村小学体育师资结构现状与对策研究

体育教师是学校体育工作的实施者,是完成体育教学任务的主要力量。因此,体育师资结构也就直接关系到学校体育工作的开展情况。本文运用问卷调查法、逻辑分析法和数理统计法,对吉林省九个地区农村小学体育师资结构的相关问题进行了客观的分析与研究,并提出了一些建议。     

吉林省农村中小学现代远程教育资源使用现状研究

本文介绍了农村中小学现代远程教育资源建设的意义,分析了资源使用状况和存在的问题,并提出了解决问题的对策。     

中国商学院人才培养目标、理念和模式再探讨

中国快速发展的经济为中国国内商学院提供了巨大的发展契机,但大部分商学院显然在人才培养的目标、理念和模式上尚未准备好迎接挑战。笔者认为应当从管理体制、人才理念、师资队伍、企业与商学院互动等方面重新探讨,塑造商学院的人才培养目标、理念和模式。     

A one-step conversion of isoquinolinium salts into naphthalene derivatives1

Berberine chloride (1) upon treatment with NaOAc-Ac₂O yields naphthalene derivatives 4 and 5 In like fashion, 8 gives naphthalene 10; isoquinoline methiodide leads to β-naphthyl acetate; and 12 provides 14. The reaction has been extended to the 3-carbonyl pyridinium series where 3-acetylpyridine methiodide and 3-pyridinecarboxaldehyde methiodide furnish lactones 16 and 17, respectively. All these transformations proceed by initial nucleophilic attack of the acetic anhydride anion on the immonium carbon atom.     

提升民族地区乡级中学图书馆(室)效能的策略

通过对大理州民族地区乡级中学图书馆(室)建设与发展现状的调查走访,阐述了当前我国民族地区乡级中学图书馆(室)普遍存在的馆藏资源数量稀少、内容陈旧、利用率较低的问题,分析了问题产生的根源,提出了提升中学图书馆(室)效能的相应对策.     

地方师范院校图书馆为中小学素质教育服务的探讨

介绍了图书馆对素质教育的价值,阐述了现有的中小学图书馆资源利用现状及地方师范院校图书馆资源优势,提出了地方师范院校图书馆服务于中小学素质教育的职能。     

关于五年一贯制模式培养农村小学教师的思考

农村小学教育师资在总体上数量不足、素质偏低、知识陈旧、年龄老化,使农村小学教育的质量受到严重影响,城乡教育差距不断拉大。利用五年一贯制的培养模式,直接招收初中毕业生进行全面、系统的小学教育专科学历教育,对建设一支数量适当、素质良好、结构合理、相对稳定、适应基础教育发展的全科型农村小学教师有重大意义。