共查询到19条相似文献,搜索用时 78 毫秒
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纳米结构自组装和分子自组装体系 总被引:16,自引:0,他引:16
系统地总结并评述了纳主结构和自组装体系和分子自组装体系的最新进展,介绍了纳米结构自组装和分子自组装的基本概念,总结了几类自组和分子自组装体系的合成方法,例举了这类自组装体系的新特性及与下一代纳米结构器件之间的联系。 相似文献
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利用快速混合停流吸收(stopped-flow absorption)技术,研究了半胱氨酸分子介导的金纳米棒线性自组装过程的动力学性质.通过观测金纳米棒的表面等离激元动态吸收光谱,分析其自组装动力学行为及其与组装结构之间的关系.研究表明,传统的二阶反应动力学理论模型在描述金纳米棒自组装动力学行为上存在明显的局限性.由此,我们提出了基于Logistic函数的新的动力学分析模型.与传统的理论模型相比,新的理论模型具有更好的普适性,不仅适用于定量分析不同速率的金纳米棒自组装动力学特征,还提供了一种更加准确地描述组装初期动力学行为的方法.此外,这种新的动力学分析方法还有助于理解和建立金纳米棒组装动力学特征与组装体结构之间的关联. 相似文献
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张蓓 《原子与分子物理学报》2021,38(2):026002-026002-8
采用模拟退火算法,系统研究了软受限条件下两嵌段共聚物自组装形貌极其转化机理。共聚物形貌可受到受限程度,组分体积分数,以及溶剂选择性3方面因素的调制。在弱受限条件下,共聚物形貌均为球状呈各向同性。核-壳-笼形貌可以极大的增加组分A和组分B之间的接触粒子数,达到增熵降能的效果,在我们的研究工作中是一种罕见的构型。形成多核结构的条件是: AB复合链末端距与其链长比值小于0.23。此次工作对于纳米颗粒的实验制作以及药品输运方面具有极大的理论指导意义。 相似文献
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采用自组装技术,利用均聚极性高分子(聚丙烯酰胺、聚乙烯醇等)长分子链作为自组装模板在半导体硅衬底上自组装生长出ZnO纳米线。采用扫描电镜(FE-SEM)和透射电镜(HRTEM)对样品的表面形貌和结构分析表征的结果表明,ZnO纳米线直径约50~80nm、长度大于4μm,具有六方纤锌矿单晶结构,且沿c轴方向择优取向生长。采用室温下光致发光(PL)谱和紫外吸收(UV)光谱对制得的ZnO纳米线的光学性能研究表明,其PL光谱上有较强的紫外发射和较弱的蓝光发射,UV吸收光谱表明样品在紫外区有强的宽带吸收,且随着纳米线粒径的减小,吸收峰出现了蓝移现象。研究探讨了高分子诱导ZnO纳米线自组装定向生长机制、发光机理及其与工艺条件的内在联系。 相似文献
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随着电子与机械元件越来越趋于小型化 ,这给科学家和工程师们提出了一个巨大的挑战 ,要求他们努力地生产出毫米和纳米量级的组件 .这个问题的可能出路之一是发展一种能使材料自组装的工艺技术 .现在 ,美国Argonne国家实验室与俄罗斯科学院微结构物理研究所的科学家们 ,正致力于发展一种新的方法 ,来促使微型粒子能自组装成一些复杂的图案结构 .在宏观领域有大量的实验曾证实 :将沙石、轴承滚珠或其他颗粒状的物质装于容器内进行搅拌 ,在重力与粒子间相互碰撞的作用下 ,通过振荡可以出现从八角的蜂窝状到无序的旋涡状等多种式样的和美丽的图… 相似文献
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Huan-Wu PENG 《理论物理通讯》1993,20(2):239-242
A general scheme is devised in the formalism of second quantization to make the Hamiltonian of an electronic system diagonal by a unitary transformation together with a suitable choice of the basis of one-electron wave functions. The scheme can be regarded as a generalization of the HartreeFodr approximation of self-consisten t field, and can be carried to any order of approximation in principle. Formulae for the lowest order approximation beyond Hartree Fodr are given. 相似文献
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In this paper, the higher-order approximation in the general theory of self-consistent field is presented by the Wick's theorem, and the solution of equations is discussed. 相似文献
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A self-consistent mean-field theory for the two-dimensional spin-1/2 XY-Heisenberg an tiferromagnet without long-range-order is developed. Within this theoretical framework, the thermodynamic properties, such as the internal energy, specific heat and parallel susceptibility, are discussed, and the results are in rough agreement with the numerical simulation. 相似文献
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R. M.L. Evans 《Contemporary Physics》2013,54(5):413-427
Complex fluids are easily and reproducibly driven into non-equilibrium steady states by the action of shear flow. The statistics of the microstructure of non-equilibrium fluids is important to the material properties of every complex fluid that flows, e.g. axle grease on a rotating bearing; blood circulating in capillaries; molten plastic flowing into a mould; the non-equilibrium onion phase of amphiphiles used for drug delivery; the list is endless. Such states are as diverse and interesting as equilibrium states, but are not governed by the same statistics as equilibrium materials. I review some recently discovered principles governing the probabilities of various types of molecular re-arrangements taking place within a sheared fluid. As well as providing new foundations for the study of non-equilibrium matter, the principles are applied to some simple models of particles interacting under flow, showing that the theory exhibits physically convincing behaviour. 相似文献
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We give a brief overview of the properties of a higher-dimensional generalization of matrix model which arise naturally in
the context of a background approach to quantum gravity, the so-called group field theory. We show in which sense this theory
provides a third quantization point-of-view on quantum gravity.
Prepared for the proceedings of Peyresq Physics 9Meeting: Micro and Macro Structureof Spacetime, Peyresq, France, 19-26 June
2004.
5 Except in 2 + 1 dimension (Witten, 1988). 相似文献
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Self-consistent calculations of the electrical and optical properties of the double-heterostructure laser have been made. Theoretical studies of both aspects of the device performance have been utilized in this work which describes the behaviour of the laser both below and at threshold. The interdependence of the electrical and optical properties of the device has been established and incorporated into a self-consistency scheme.A computer program has been developed to perform the calculations given the specification of device parameters. Within the program the transport equations are solved, the active region refractive index calculated and then used in the waveguide theory. From the solution to the waveguide equations a lasing frequency and threshold current for the specified cavity mode are obtained. A consistency criterion is applied between the transport and waveguide parts of the theory.The program allows the performance of the laser to be monitored providing such information asI–V characteristics, near and far field patterns for various cavity modes with their threshold currents and lasing frequencies. 相似文献
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Kh. Namsrai 《International Journal of Theoretical Physics》2003,42(11):2609-2704