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本文从实验实际认真研究了镁与水、铝与水的反应,对高中课本中关于镁与水反应的知识介绍进行了质疑,提出了修订意见。并对镁与氯化铵溶液的反应谈了自己的看法。 相似文献
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两种细菌的毛细管电泳分离及其与药物相互作用的研究 总被引:4,自引:0,他引:4
通过对大肠杆菌与金黄色葡萄球菌的毛细管电泳行为的研究,包括对细菌样品预处理、缓冲液、检测波长以及聚合物添加剂对分离度的改进等的考察,在优化的实验条件下,实现了大肠杆菌与金黄色葡萄球菌的快速分离,从而建立一种新的细菌辅助识别与定性的补充方法。将抗菌药物阿奇霉素与金黄色葡萄球菌混合培育,发现由于阿奇霉素抑制细菌表面蛋白合成,造成与金黄色葡萄球菌作用后,细菌表面电荷密度降低,表现为阿奇霉素对金黄色葡萄球菌的电泳淌度的影响,而且培育时间与金黄色葡萄球菌的淌度线性相关。 相似文献
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目前农村初中对实验教学仍不够重视,实验开设率不高、对实验教学缺少研究,导致部分教师实验技能下降:对实验操作步骤不熟悉、实验操作细节不规范、实验后处理不到位等。要提高对实验教学重要性的认识、加强对教科书的学习与研究、注重对实验的实践与研究、加强实验室建设与管理,以提高教师的实验操作技能,推动实验教学正常有序地开展。 相似文献
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化学教学情景与化学教学情境辨析 总被引:2,自引:1,他引:1
“情境”与“情景”这2个词有时会出现在同一篇文章中。通过对“情境”与“情景”的比较,尤其是通过对化学教学“情境”与化学教学“情景”进行比较,说明二者的区别与联系,以便广大化学教师加深对这一问题的理解和应用。 相似文献
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理解著文强化记忆——化学研究性学习过程中穿插诗歌教学的尝试 总被引:3,自引:0,他引:3
将诗歌引入到化学教学中,增强了学生对化学知识的理解,促使了学生对化学知识的记忆,加强了化学知识与社会、与相关学科的联系,是研究性学习的一种尝试。文中介绍了对在化学学习过程中穿插诗歌教学的理解与做法。 相似文献
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用圆二色谱(CD)研究海藻酸钠对钙锌离子的选择 总被引:1,自引:0,他引:1
用圆二色谱对海藻酸钠与钙锌离子相互作用的稳态溶液-凝胶过程进行了研究,结果表明该过程分前后两个阶段,在临界点之前第一阶段内,海藻酸钠构象的变化与阳离子用量成线性关系。对海藻酸钠与钙锌离子的选择识别和相互作用研究表明,钙离子与海藻酸钠的G、M单元相互作用差别很大,锌离子与G、M单元相互作用的差别比较小,锌离子对G、M单元的识别作用不如钙离子。锌离子与海藻酸钠形成凝胶时,交联点比钙离子的多。 相似文献
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有机物对水体的污染严重威胁生态环境安全和人类健康。 如何有效控制和消除水体系中的有机污染物是当前全球性热点问题之一,基于多孔材料的高效吸附是处理水体有机污染的有效方法。 多孔有机聚合物(Porous Organic Polymers,POPs)具有比表面积高、物理化学稳定性好、易修饰等特点,作为新型吸附剂在处理水体系有机污染方面具有广阔的应用前景。 本文综述了近10年来新型多孔有机聚合物对水体系中有机溶剂、农药与杀虫剂、有机染料等污染物的吸附分离研究进展。 相似文献
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Hui-Chao Ma Jie Zou Xue-Tian Li Dr. Gong-Jun Chen Prof. Yu-Bin Dong 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(61):13754-13770
Owing to their permanent porosity, highly ordered and extended structure, good chemical stability, and tunability, covalent organic frameworks (COFs) have emerged as a new type of organic materials that can offer various applications in different fields. Benefiting from the huge database of organic reactions, the required functionality of COFs can be readily achieved by modification of the corresponding organic functional groups on either polymerizable monomers or established COF frameworks. This striking feature allows homochiral covalent organic frameworks (HCCOFs) to be reasonably designed and synthesized, as well as their use as a unique platform to fabricate asymmetric catalysts. This contribution provides an overview of new progress in HCCOF-based asymmetric catalysis, including design, synthesis, and their application in asymmetric organic synthesis. Moreover, major challenges and developing trends in this field are also discussed. It is anticipated that this review article will provide some new insights into HCCOFs for heterogeneous asymmetric catalysis and help to encourage further contributions in this young but promising field. 相似文献
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无机材料电子迁移率高、光谱响应范围与太阳光谱匹配,而有机材料价格低廉、合成方法简单、容易制作在基底上,因此在太阳能电池中具有更广阔的应用前景。 目前,阻碍有机太阳能电池发展的主要原因是材料的载流子迁移率低、器件稳定性差、吸收光谱与太阳光谱不匹配,导致光电转换效率较低。 若能将有机、无机材料二者的优点相结合,将可提高有机太阳能电池的能量转换效率。 目前的研究已经取得了一定进展,无机材料在受体层、阴极缓冲层、阳极缓冲层中的应用均不同程度地提高了有机太阳能电池的能量转换效率。 本文综述了目前该领域的研究现状,并对今后的研究提出了展望。 相似文献
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For the past 75 years, physical organic chemistry has been the foundation for the elucidation of mechanisms, and the understanding of structure/activity relationships, in organic chemistry. The rational design of experiments and the critical analysis of data have been the hallmarks of this field. In this Perspective, we revisit some of the studies carried out during the past 30 years in which our group has used the tools of physical organic chemistry to investigate the mechanisms of a variety of organometallic reactions. The Perspective covers a broad spectrum of metal-mediated reactions including organic reductions, alkene, carbon monoxide and nitric oxide migratory insertion reactions, C-H bond activation, and the reactions of metal-heteroatom bonds with organic molecules. These studies, along with similar ones carried out in other groups, have demonstrated that the principles and methods of physical organic chemistry have adapted well to the study of organometallic reaction mechanisms. The understanding obtained in this way has aided the development of useful metal-mediated reactions in a wide range of areas, especially in industrial catalysis and in applications to problems in organic synthesis. 相似文献
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分子识别指导下的有机分子设计、合成和组装——世纪交替时代的有机化学 总被引:3,自引:2,他引:1
在21世纪即将来临之际,有机化学将面临生命科学、环境科学和材料科学越来越多的挑战。本文回顾了在分子识别指导下的有机分子的设计、合成和组装这个新领域的诞生和发展,认为这个领域将成为新世纪有机化学发展的一个重要方向。它的发展和应用不仅使得有机化学可能较好地面对新挑战,同时能推动有机合成化学自身的发展。 相似文献
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合成钛硅分子筛TS-1的一种新方法 总被引:4,自引:0,他引:4
In both conventional method[1] and modified method[2] ,organic Si and Ti alkoxides were used as Si source and Ti source respectively, and only strong organic base was used. So this system may be called as organic synthesis one (see Fig 1 )Thangaraj et al[3] reported that in the organic synthesis system only organic strong base TPAOH can be used. 相似文献
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We synthesise a novel poly(ionic liquid) (PIL) and develop a procedure that allows the phase transfer of graphene oxides (GO) from water to organic solvent, retaining graphene oxide liquid crystal (GOLC) phase in various organic solvents, especially non-polar organic solvents. PIL ([PEP-MIM]DBS) is exploited in this procedure as a noncovalent functional material that is capable of transporting GO from aqueous to non-polar organic phase. PILs can decorate GO noncovalently and keep GO nano-sheets exfoliated in solid-state PILs/GO hybrids, which can well redisperse in organic solvents without any agglomeration. This expands the number of known solvents which can support GOLC phase to dimethyl formamide, dimethyl sulfoxide, acetonitrile, tetrahydrofuran, and a number of other non-polar organic solvents, many of which were not known to afford GOLC phase prior to this report, such as dichloromethane, tetrachloromethane, dichloroethane and tetrachloroethane. 相似文献