共查询到20条相似文献,搜索用时 15 毫秒
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Y. G. Molotkovskii L. F. Nikulina L. D. Bergel'son 《Chemistry of Natural Compounds》1972,5(4):179-181
Conclusions 1. A. new route for the synthesis of optically active ,-diglycerides has been developed.2. D- and L-, -Distearins and D-, -dilinolenin have been synthesized from the readily accessible L- and D--O-tritylglycerols.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 210–214, 1969 相似文献
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K. I. Pashkevich G. B. Afanas'eva E. G. Kovalev I. Ya. Postovskii 《Chemistry of Heterocyclic Compounds》1970,6(10):1226-1231
The -electron charges, bond orders, and energy levels of phenoxazin-3-one and eight of its mono- and diannelated derivatives were calculated by the Hückel MO LCAO method. The effect of the position of the annelated benzene ring on the electronic characteristics of the compounds was estimated. A satisfactory correlation between the experimental and calculated energies of the 1 1 transitions was found.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1316–1322, October, 1970. 相似文献
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Pier Luigi Luisi 《Foundations of Chemistry》2002,4(3):183-200
The main aim of the paper is to reinforce the notion that emergence is a basic characteristic of the molecular sciences in
general and chemistry in particular. Although this point is well accepted, even in the primary reference on emergence, the
keyword emergence is rarely utilized by chemists and molecular biologists and chemistry textbooks for undergraduates. The
possible reasons for this situation are discussed. The paper first re-introduces the concept of emergence based on very simple
geometrical forms; and considers some simple chemical examples among low and high molecular weight compounds. On the basis
of these chemical examples, a few interesting philosophical issues inherent to the field of emergence are discussed – again
making the point that such examples, given their clarity and simplicity, permit one to better understand the complex philosophical
issues. Thus, the question of predictability is discussed, namely whether and to what extent can emergent properties be predicted
on the basis of the component’s properties; or the question of the explicability (a top down process). The relation between
reductionism and emergentism is also discussed as well as the notion of downward causality and double causality (macrodeterminism);
namely the question whether and to what extent the emergent properties of the higher hierarchic level affect the properties
of the lower level components. Finally, the question is analyzed, whether life can be considered as an emergent property.
More generally, the final point is made, that the re-introduction of the notion of emergence in chemistry, and in particular
in the teaching, may bring about a deeper understanding of the meaning of chemical complexity and may bring chemistry closer
to the humanistic areas of philosophy and epistemology.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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化学学科的现状及基础化学教育改革问题 总被引:29,自引:0,他引:29
1 化学学科现状简介 自 1 80 2年道尔顿提出原子假说 ,1 81 1年阿佛加德罗又提出分子学说以来 ,化学一直在原子和分子学说的基础上发展着。 1 86 9年门捷列夫所发现的元素周期律及在此基础上构成的元素周期表 ,使化学从而成为一门有着严密体系的学科。由于当时对于原子和分子的结构理论还停留在假说的阶段 ,化学家的研究工作主要侧重于元素的发现、分析或分离组成复杂的样品的方法以及新化合物的合成 ,所以化学的传统定义中只强调合成和分析两个方面。这个传统在基础化学教育中至今仍然有着深刻的影响。 2 0世纪物理学家对原子结构及有… 相似文献
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E. A. Parfenov G. A. Serebrennikova S. Ya. Roitberg N. A. Preobrazhenskii 《Chemistry of Natural Compounds》1968,2(6):299-302
Summary 1. The synthesis of the following neutral plasmalogens has been effected: -O-(octadec-1-enyl)-, distearoylglycerol, -O-(octadec-1-enyl)-, -dipalmitoylglycerol, -O-(hexadec-1-enyl)-, -distearoylglycerol, and -O-(pentadec-1-enyl)-, -dipalmitoylglycerol.2. During the synthesis, the following compounds were isolated and characterized by their physicochemical constants: the -octadec-1-enyl ether of glycerol, -(2-hydroxyoctadecyl) , -isopropylideneglyceryl ether, the tosylate of -(2-hydroxyoctadecyl) , -isopropylideneglyceryl ether, and -O-(2-tosyloxyoctadecyl) glycerol.3. The IR spectra of the -octadec-1-enyl ether of glycerol and the neutral plasmalogens have been studied.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 6, pp. 367–371, 1966 相似文献
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G. A. Serebrennikova E. A. Parfenov N. I. Serebryakova N. A. Preobrazhenskii 《Chemistry of Natural Compounds》1966,1(5):249-251
Summary A number of derivatives of androstano [3, 2-b] pyrylium and androst-13-eno-[3, 2-b] pyrylium derivatives forming a new class of heterocyclic steroids has been obtained.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 5, pp. 318–321, 1965 相似文献
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Summary A method for the separate quantitative determination of the furocoumarins ofFicus carica has been developed.Khimiya Prirodnykh Soedinenii, Vol. 3, No. 5, pp. 295–298, 1967 相似文献
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Martin Scherer Patrick Scheibe Jérôme Schoenhentz Anja Hoffmann-Röder Rudolf Zentel 《Colloid and polymer science》2014,292(8):1803-1815
This paper deals with pattern formation in Langmuir monolayers of two sets of lipid mixtures that include (1) a fluorinated lipid for phase separation, (2) a polymerizable lipid for stabilization of the patterned structure, and (3) a unit for the presentation of biological recognition units. Differences in the distribution of these functionalities allow a polymerization of dispersed or continuous phase and a placement of the recognition units in crystalline or solid analogue phase. Also, a ternary mixture including a lipid modified with the tandem repeat domain of MUC1 plus a TN-antigen was studied. Based on the biphasic pattern obtained (starlike crystals of up to 50 μm with a fine structure of some micrometers), we also verified the potential of the laterally patterned monolayer to stimulate the immune system (quartz crystal microbalance). The second set of lipids combines a highly fluorinated itaconic ester (polymerizable unit) with the natural phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine. 相似文献
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Chemistry of Natural Compounds - 相似文献
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基于Internet的化学学习模式与化学网络资源的利用 总被引:4,自引:0,他引:4
Internet技术的迅速发展 ,给化学教育带来了前所未有的冲击 ,为化学教育改革注入了活力。化学作为一门以实验为基础的学科 ,可以很好地与Internet技术结合 ,Internet巨大的信息资源的开发与利用已经发展成为一种能适应网络时代化学教育需求的全新的学习模式。分析并提出了基于Internet的网络教育的化学学习模式 ,以及如何在化学教育中深化网络信息资源的开发和利用。 相似文献