The complexing ability of crown ethers incorporating glucose

The complexing (in CHCl₃) and extracting abilities of 18-crown-6 type compounds (1–15) were measured with Li, Na, K and NH₄ cations. The substituents on the sugar part affected these properties significantly (K _a=10³–10⁷). Some substituents, like acetyloxy groups (3) decreased whereas others, like tosyloxy groups (10, 11) significantly increased the complexing ability and thus changed the selectivity. The compound with four tosyloxy groups (11) shows an excellent picrate salt extracting ability in a CH₂Cl₂-water system.     

“双一流”背景下高等农业院校有机化学基础课程教学新模式的构建及实践

The crop science of Sichuan Agricultural University is an authorized first-class discipline. As the strategic supporting department for innovative talent cultivation in agriculture and forestry major, we are facing a long-term challenge in reforming the teaching mode for basic course-organic chemistry and cultivating talented students with solid basic knowledge and strong sense of innovation. Herein a thorough survey was performing to establish the executable teaching programs for this course during the "Double-First Class Universities Plan" period. A multidimensional teaching resource library for organic chemistry course was also constructed. The new classroom teaching mode "Interest cultivation-Creative thought development-Autonomous and Cooperative learning", along with a stepwise practice teaching mode "Foundation skills-Integrated application-Innovative trial" was proposed and practiced among thirty-five majors including agriculture, forestry and veterinary, to improve the quality for innovative talent cultivation and support our first-class discipline construction. This research could probably serve as a reference for congeneric agricultural university.     

Surfactants having polyfluoroalkyl chains. II. Syntheses of anionic surfactants having two polyfluoroalkyl chains including a trifluoromethyl group at each tail and their flocculation-redispersion ability for dispersed magnetite particles in water

Anionic surfactants having two polyfluoroalkyl chains per molecule, i.e. the sodium salt of bis(1H, 1H, 2H,2H-heptadeca-fluorodecyl)-2-sulfosuccinate, CF₃(CF₂)₇(CH₂)₂OCOCH₂CH(SO₃Na)COO(CH₂)₂(CF₂)₇CF₃, the sodium salt of bis(1H, 1H, 2H, 2H-tridecafluoro-octyl)-2-sulfosuccinate, CF₃(CF₂)₅(CH₂)₂OCOCH₂CH(SO₃Na)COO(CH₂)₂(CF₂)₅CF₃, and the sodium salt of bis(1H, 1H, 2H, 2H-nonafluorohexyl)-2-sulfosuccinate, CF₃(CF₂)₃(CH₂)₂OCOCH₂CH(SO₃Na)COO(CH₂)₂(CF₂)₃CF₃, have been prepared from maleic anhydride, the corresponding alcohols possessing a polyfluoroalkyl chain and sodium hydrogen sulfite. The flocculation and redispersion abilities of these surfactants for dispersed magnetic particles in water have been examined to investigate the effect of the chain length. It was found that this ability was enhanced by an increase in the chain length. The contact angles for water for pelleted surface-modified magnetite have been measured. In order to compare this ability and the contact angles, data for other fluorinated surfactant have been obtained. The Kraff point, the surface tension and the pNa of the aqueous surfactant solutions have also been measured.     

“保守系统平衡位置微振动”案例教学的探讨与实践

以“保守系统平衡位置微振动”为例,论述在理论力学中如何适当地整合知识点使之成为一个案例,使学生从具体的案例出发经过思考、分析、讨论,得到可能的解决方案,并进行评价、提炼理论.实践证明,把案例教学引入理论力学教学中,通过多个阶段的实践过程锻炼,有助于学生形成“主体性”和“实践性”的习惯,从而改善课堂教学关系,提高学生的独立学习和实践创新能力.     

美国NGSS科学与工程实践构架与化学教学案例——影响化学反应速率的因素

美国《新一代科学标准》（NGSS）强调科学实践的重要性并提出科学与工程实践的关键要素，不仅为科学实践的具体实施提供了方向而且使科学实践的评价标准更加明确。在介绍NGSS科学与工程实践的构架基础上，以“影响化学反应速率的因素”为例分析了科学与工程实践的关键要素在教学中的反映及实施特点，并基于案例分析提出对我国中学化学教学过程设计的借鉴与启示。     

基于应用型本科生创新能力培养的教学改革研究*

基于应用型本科院校创新型人才的培养目标,对本科生开展科研训练,将科研训练纳入教学过程,从课程体系、教学环节、教学手段、考核评价等方面进行了探索,构建了以科研训练为主线的研究型教学模式。     

在线教学的实践与反思*——以有机化学课程为例

以有机化学课程在线教学开展情况为背景,通过与传统教学模式对比,分析了在线教学的优势与不足。在此基础上,将笔者所在课程组开展在线教学以来在教学内容重构、教学环节设计、考核方式改革等方面的探索与尝试进行了总结与分享。     

Role of compositional changes on thermal,magnetic,and mechanical properties of Fe-P-C-based amorphous alloys

This work aimed to tune the comprehensive properties of Fe-P-C-based amorphous system through investigating the role of microalloying process on the crystallization behavior,glass forming ability(GFA),soft magnetic features,and mechanical properties.Considering minor addition of elements into the system,it was found that the simultaneous microalloying of Ni and Co leads to the highest GFA,which was due to the optimization of compositional heterogeneity and creation of near-eutectic composition.Moreover,the FeCoNiCuPC amorphous alloy exhibited the best anelastic/viscoplastic behavior under the nanoindentation test,which was owing to the intensified structural fluctuations in the system.However,the improved plasticity by the extra Cu addition comes at the expense of magnetic properties,so that the saturation magnetization of this alloying system is significantly decreased compared to the FeCoPC amorphous alloy with the highest soft magnetic properties.In total,the results indicated that a combination of added elemental constitutes,i.e.,Fe69Co5Ni5Cu1P13C7 composition,provides an optimized state for the comprehensive properties in the alloying system.     

地方高校高分子材料与工程专业生产实习协同创新模式探讨

地方高校已成为我国高等教育的重要组成部分,由于办学目标、生源构成、服务地区不同于部属高校,其生产实习教学环节面临各种困境。寻求有效的途径突破生产实习的困境成为当前各地方高校亟待解决的问题。本文以广东工业大学为例,在分析该校的办学特点以及高分子材料与工程专业近年来生产实习状况的基础上,介绍该校以大学联盟为平台的生产实习新模式,并详细说明其实施方案。该模式基于该校的协同创新战略,已取得良好的教学效果。     

关注长江水质——“绿行之踪”社会实践

2018年和2019年小学期,厦门大学本科生"绿行之踪"社会实践队赴重庆、上海等长江流域主要城市进行社会实践活动,采集了当地的水样,测定了水样中的磷酸根含量和高锰酸盐指数,同时进行了水资源保护的宣传活动和网络问卷调查。