中医药类大学有机化学“第一堂课”教学实践探索

有机化学内容覆盖面广,知识博大精深,学生在学习时普遍感到内容多、头绪乱。笔者多年来一直探索一种行之有效的方法,能在“第一堂课”的教学中引导学生真正理解各类有机反应发生的原因、反应历程及相关规律,消除学生的畏难情绪,激发学生的学习热情。     

决明子生芽转化有机铬的效果研究

利用透析方法将不同时间点收获的富铬决明子芽中的有机铬和无机铬分开,用石墨炉原子吸收分光光度法测定富铬决明子芽中的总铬含量和无机铬含量,计算出各时间点收获的决明子芽的有机铬转化率。探讨决明子生芽转化有机铬的效果。培育时间对决明子芽有机铬转化率有一定影响,在本实验条件下,72h是培育富铬决明子的适宜时间段。     

The effectiveness of Web search engines for retrieving relevant ecommerce links

Ecommerce is developing into a fast-growing channel for new business, so a strong presence in this domain could prove essential to the success of numerous commercial organizations. However, there is little research examining ecommerce at the individual customer level, particularly on the success of everyday ecommerce searches. This is critical for the continued success of online commerce. The purpose of this research is to evaluate the effectiveness of search engines in the retrieval of relevant ecommerce links. The study examines the effectiveness of five different types of search engines in response to ecommerce queries by comparing the engines’ quality of ecommerce links using topical relevancy ratings. This research employs 100 ecommerce queries, five major search engines, and more than 3540 Web links. The findings indicate that links retrieved using an ecommerce search engine are significantly better than those obtained from most other engines types but do not significantly differ from links obtained from a Web directory service. We discuss the implications for Web system design and ecommerce marketing campaigns.     

应用型化工专业有机化学教学案例

为了提高学生学习有机化学的兴趣和综合运用知识的能力,为应用型化工专业有机化学课程设计了一个教学案例,涉及有机化学课程的多个知识点,有助于学生对知识的全面掌握。     

论金华市有机茶发展的对策

有机食品是当今社会普遍追求的无污染健康食品，食品有机化引导消费向更高要求转变。本文通过对金华市茶叶生产现状分析，从生产、加工、销售各环节提出了实现有机茶生产产业化的途径。     

Optimization of technological conditions for one-pot synthesis of (S)-α-cyano-3-phenoxybenzyl acetate in organic media

Optically active form of α-cyano-3-phenoxybenzyl (CPB) alcohol, building block of pyrethroid insecticides, was synthesized as its acetate by the combination of anion-exchange resin (D301)-catalyzed transcyanation between m-phenoxybenzaldehyde (m-PBA) and acetone cyanohydrin (AC), and lipase (from Alcaligenes sp.)-catalyzed enantioselective transesterification of the resulting cyanohydrin with vinyl acetate. Through optimizing technological conditions, the catalyzing efficiency was improved considerably compared to methods previously reported. Concentrations of CPB acetate were determined by gas chromatograph. The enantio excess (e.e.) values of CPB acetate were measured by NMR (nuclear magnetic resonance) method. Effects of solvents and temperatures on this reaction were studied. Cyclohexane was shown to be the best solvent among the three tested solvents. 55 ℃ was the optimal temperature for higher degree of conversion. External diffusion limitation was excluded by raising the rotational speed to 220 r/min. However, internal diffusion could not be ignored, since the catalyst (lipase) was an immobilized enzyme and its particle dimension was not made small enough. The reaction rate was substantially accelerated when the reactant (m-PBA) concentration was as high as 249 mmol/L, but decreased when the initial concentration of m-PBA reached to 277 mmol/L. It was also found that the catalyzing capability of recovered lipase was high enough to use several batches. Study of the mole ratio of AC to m-PBA showed that 2:1 was the best choice. The strategy of adding base catalyst D301 was found to be an important factor in improving the degree of conversion of the reaction from 20% to 80%. The highest degree of conversion of the reaction has reached up to 80%.     

有机硅油的理化特性及其在医疗保健中的奇特用途

本文浅析了有机硅油具有非凡的抗热、消泡、抗水、抗氧性、化学隋性、生理隋性和柔韧性,展望了有机硅在医疗保健制品中所具有的广泛而奇特的用途。     

三论中国国家创新体系的有机构成——观念与文化创新

中国国家创新体系不仅包括知识创新系统和技术创新系统，而且由于中国的国情，它还应该包括体制与制度创新系统、观念与文化创新系统和知识基础设施与管理工程系统。该文就是专论观念与文化创新系统存在的必要性和可行性。认为观念与文化落后，必定导致经济落后，要想超前发展，第一就是观念与文化创新。舍此就很难在中国发展知识经济。     

四氯化锡催化剂在精细有机合成中的应用研究进展

本文从化学反应类型出发,综述了四氯化锡催化剂在精细有机合成中的研究进展,展望了四氯化锡作为新型催化剂的发展前景。     

大学生村官面临的法律问题研究

大学生村官政策是当前我国为建设新农村而实施的一项重大政策,取得了很大成效,但也存在一些法律问题。大学生担任村官不但没有法律依据,还违反了《中华人民共和国村委会组织法》的有关规定;由于大学生村官没有任职村的户籍,因此他们没有选举村委会成员的权利,也没有被选举为村委会成员的权利。解决这个问题有两个方法：或者修改村委会组织法第十一条,使大学生根据法律的规定直接担任村官,或者把大学生村官的户口迁移到所任职的村,使他们具有该村的户籍。