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以1978年改革开放以来人民教育出版社出版的5套高中化学教科书作为研究对象,梳理其物质结构内容的演变,发现近40年来高中化学教科书中物质结构内容选择呈钟摆现象,同时其内容组织的结构化理念日益清晰。此外,为新时期我国高中化学教科书的编写提供了一些建议。 相似文献
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Meng Zang Chaocheng Zhao Yongqiang Wang Shuiquan Chen 《Journal of Saudi Chemical Society》2019,23(6):645-654
Along with the rapid development of industry, VOCs gradually move into the spotlight, and now become a kind of harmful environmental pollutants that cannot be overlooked. This paper introduces the hazards of VOCs and the common catalytic combustion catalysts, noble metal catalysts and non-noble metal catalysts, for the elimination of VOCs. Perovskite catalysts, as one of the non-noble catalysts, play an important role in the field of catalytic combustion in recent years. According to the classification of elements doping in perovskites, the research achievements in the past five years were analyzed and reviewed. In addition, this paper also analyzes and elaborates the reaction kinetics and QSAR/QSPR models for the introduction of structural properties and reaction mechanisms. 相似文献
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Laxmi Narayan Tripathi Sourabh Barua 《Progress in Crystal Growth and Characterization of Materials》2019,65(4):100465
This review article covers the growth and characterization of two-dimensional (2D) crystals of transition metal chalcogenides, h-BN, graphene, etc. The chemical vapor transport method for bulk single crystal growth is discussed in detail. Top-down methods like mechanical and liquid exfoliation and bottom-up methods like chemical vapor deposition and molecular beam epitaxy for mono/few-layer growth are described. The optimal characterization techniques such as optical, atomic force, scanning electron, and Raman spectroscopy for identification of mono/few-layer(s) of the 2D crystals are discussed. In addition, a survey was done for the application of 2D crystals for both creation and deterministic transfer of single-photon sources and photovoltaic systems. Finally, the application of plasmonic nanoantenna was proposed for enhanced solar-to-electrical energy conversion and faster/brighter quantum communication devices. 相似文献
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AbstractEnlightened by the Caputo fractional derivative, the present study deals with a novel mathematical model of generalized thermoelasticity to investigate the transient phenomena due to the influence of magnetic field and moving heat source in a rod in the context of three-phase lag (TPL) theory of thermoelasticity. Both ends of the rod are fixed and heat insulated. Employing Laplace transform as a tool, the problem has been transformed into the space-domain and solved analytically. Finally, solutions in the real-time domain are obtained by applying the inverse Laplace transform. Numerical calculation for stress, displacement, and temperature within the rod is carried out and displayed graphically. The effect of moving heat source speed on temperature, stress, and temperature is studied. It is found from the distributions that the temperature, thermally induced displacement and stress of the rod are found to decrease at large source speed. For the better understanding of the effect of moving heat source on all the distributions, three animations are added. 相似文献
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利用史料记录建立了明代生命损失型地震的数据库,构建生命损失型地震等级序列、10 a尺度上生命损失型地震的频次序列和县次序列,再现明代生命损失型地震的时空分布特征,探讨了生命损失型地震发生及导致人口死亡的时空差异原因。结果表明:(1)从明初到明末,生命损失型地震等级强度有逐渐扩大的趋势。(2)明代前期处于生命损失型地震发生较少的稳定时期;明代中后期处于生命损失型地震发生较多的波动时期。明代生命损失型地震发生频次存在明显的周期性变化特征。(3)生命损失型地震在明代大部分区域皆有分布。灾害重心随时间变化发生移动,由西南到中部再到华北、华东。(4)明代地震频繁的原因除地球本身因素外,太阳活动通过影响气候变化,进而间接影响地壳活动。气候寒冷与干旱和地震有较好的对应关系。明代后期生命损失型地震导致死亡人数大量增加,与明代经济发展,人口密度逐渐增长有关;不同地区生命损失型地震导致的死亡人数不同,且死亡人数与地震频发地区是否处于板块之间的活动构造带和人口分布密度有关。 相似文献
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Florio M. Ciaglia Fabio Di Cosmo Alberto Ibort Giuseppe Marmo 《Entropy (Basel, Switzerland)》2020,22(11)
The evolution of states of the composition of classical and quantum systems in the groupoid formalism for physical theories introduced recently is discussed. It is shown that the notion of a classical system, in the sense of Birkhoff and von Neumann, is equivalent, in the case of systems with a countable number of outputs, to a totally disconnected groupoid with Abelian von Neumann algebra. The impossibility of evolving a separable state of a composite system made up of a classical and a quantum one into an entangled state by means of a unitary evolution is proven in accordance with Raggio’s theorem, which is extended to include a new family of separable states corresponding to the composition of a system with a totally disconnected space of outcomes and a quantum one. 相似文献
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