共查询到20条相似文献,搜索用时 15 毫秒
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Christoph Meinel 《Angewandte Chemie (International ed. in English)》1984,23(5):339-347
In 1751, the Swedish chemist Johan Gottschalk Wallerius first differentiated between “pure” and “applied” chemistry, a distinction which was quickly adopted by the other branches of science. Behind this was a new scientific concept of chemistry which emphasized the importance of applying chemistry's accumulated knowledge and its capabilities of providing for the general economic benefit. It also provided chemistry with a new position within the hierarchy of the sciences as well as with a new function in society. The reasons behind and causes of the change in scientific perspective associated with this concept point to the social and institutional conditions under which this field has developed into an independent academic discipline. 相似文献
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R. Lizrraga L. Nordstrm E. Sjstedt O. Eriksson 《International journal of quantum chemistry》2002,90(6):1610-1613
The spin and orbital magnetic moments of VAu4 have been calculated using a first principles method that allows for noncollinear magnetic ordering. The large spin–orbit coupling of the Au atom is argued to induce large noncollinear components of the magnetization density as well as a parallel coupling between spin and orbital moments of the V atom, in contrast to expectations from Hund's third rule. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002 相似文献
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在借鉴已有科学史融入其他学科教学模式的基础上,针对目前化学史融入中学化学课程的实际教学现状,经过多次教学实践的检验,提出了一种将化学史有效融入中学化学教学实践的“历史线”“探究线”“知识线”和“应用线”的四线式教学模式,该模式可将化学核心素养的培养贯穿于整个教学之中。 相似文献
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Hans-Jürgen Quadbeck-Seeger 《Angewandte Chemie (International ed. in English)》1990,29(11):1177-1188
A particularly close relationship exists between chemistry, the science of the transformation of matter, and developments in human living conditions. Though little more than 150 years old, chemical technology has had a greater influence on our civilization than any other technological discipline. Its roots lie not in the crafts, but in scientific research. Relationships derived from the laws of nature were taken as a basis for the systematic solution of practical problems. It is to this strategy that chemistry owes its success. New opportunities arise from new discoveries. These result from basic research at universities, research institutes, and industrial laboratories. Applied research in turn transforms the discoveries into innovative solutions to problems on an industrial scale. The objectives of applied research are oriented toward the marketplace and to the needs of mankind. Our knowledge of scientific interrelationships has been growing with unabated vigor for decades, but so too has our insight into the enormous complexity of the material world. Many of the problems that civilization faces result from the fact that our knowledge is still inadequate. Intensive research and development offer the only hope for progress. Scientists must of course act responsibly with the knowledge they acquire, and they must provide the information necessary to establish public confidence in their methods and products. This is the prerequisite for broad acceptance of technological progress, and given the extent of the world's population no alternative to progress exists. The shape of that progress is also subject to influences outside the realm of science, however, including social norms and political activities. A country that is not rich in raw materials, like the Federal Republic of Germany, must pay particular attention to these factors as well if it is to maintain its innovative strength. 相似文献
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Adolf Echte Franz Haaf Jürgen Hambrecht 《Angewandte Chemie (International ed. in English)》1981,20(4):344-361
Hermann Staudinger, the founder of polymer chemistry, would have been 100 years old this year. One of the key materials with which he elucidated the structure of high polymers was polystyrene.—Polystyrene, one of the most important thermoplastics, has now been manufactured industrially for some 50 years. Not only has it simplified our daily lives in a variety of ways, it has also been a model substance for the development and expansion of polymer chemistry and polymer physics, and it was the pioneering material for handling polymer solutions and melts. This article surveys the development and present state of knowledge of the polymerization of styrene and of the relationships between structure and properties. 相似文献
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化学知识是环境化学知识的基础。化学概念和理论能够对大气环境中的化学反应、土壤环境中的化学反应、水体环境中的化学反应以及水体中存在的平衡等内容进行分析和解释。环境化学知识是运用化学知识研究物质的环境化学行为以及治理化学污染物质而形成的知识体系。对环境化学问题的深入研究能够促进化学的发展。 相似文献
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D. Thorburn Burns Maria Filomena G. F. C. Camões António M. Amorim da Costa 《Mikrochimica acta》2005,152(1-2):137-151
The people and places of importance in the history of chemistry in Portugal have been reviewed with particular reference to
analytical chemistry. 相似文献
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Youhei Maruyama Kenta Hongo Masanori Tachikawa Yoshiyuki Kawazoe Hiroshi Yasuhara 《International journal of quantum chemistry》2008,108(4):731-743
Hund's spin‐multiplicity rule for the ground state of the methylene molecule CH2 is interpreted by Hartree‐Fock (HF) and multi‐reference configuration interaction (MRCI) methods. The stabilization of the triplet ground state ( 3B1) relative to the second singlet excited state ( 1B1) is ascribed to the greater electron‐nucleus attraction energy that is gained at the cost of increasing the electron‐electron repulsion energy and with the aid of a reduction in the nucleus‐nucleus repulsion energy. The highest spin‐multiplicity in the ground state of CH2 is accompanied by a set of three characteristic features, i.e., elongation of the internuclear distances, reduction in the bond angle, and contraction of the valence electron density distribution around the nuclei involving expansion of the core electron density distribution. The present calculations fulfill the virial theorem to an accuracy of ?V/T = 2.000 for both HF and MRCI. Accordingly, the molecular geometries are optimized for each of the two states. The inclusion of correlation by MRCI method reduces the energy splitting between the two states by about 14%. The energy splitting is analyzed by the correlational virial theorem 2Tc + Vc = 0 to make a clear interpretation of the correlation effect.© 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 相似文献
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Prof. Dr. François Diederich 《Angewandte Chemie (International ed. in English)》2013,52(10):2714-2742
This Review investigates the development of Angewandte Chemie since the founding of the journal in 1887 and analyzes how its content reflects the changes in chemical research over these 125 years. Although Angewandte Chemie was originally founded as a journal for applied (“angewandte”)—technical and analytical—chemistry, numerous review articles and abstracts published even in its first 50 years enable the milestones in chemical research in a much broader sense to be traced nicely. With the introduction of the International Edition in 1962, the author base, which had until then been primarily limited to German‐speaking countries, became increasingly international, and the journal experienced impressive growth. Today, with its attractive layout, successful mix of articles, and high impact factor, Angewandte Chemie covers chemical research around the world in its full breadth, with its many achievements and future challenges. 相似文献
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Dr. Jeffrey I. Seeman 《Chemical record (New York, N.Y.)》2023,23(1):e202200239
Previous publications in this series on the history of the development of the Woodward–Hoffmann rules revealed why Woodward and Hoffmann were prime candidates to solve the pericyclic no-mechanism problem. This publication explains why it was the collaborative team of R. B. Woodward and Roald Hoffmann who did solve this mechanistic problem in a series of five communications in the Journal of the American Chemical Society in 1965. That is, the reasons why Woodward and Hoffmann were the perfect team, and why their individual capabilities, experiences, and qualities provided the perfect synergy are described. In part, this was the right time and the right place for them both, but the synergies were fundamental, intrinsic and idiosyncratic as a collaborative pair. Their orbital symmetry rules provided the mechanism of all concerted pericyclic reactions including electrocyclizations, cycloadditions, and sigmatropic rearrangements. Why it was 1965 and not earlier is also discussed. 相似文献