1、专业英语复试题-1Mesocrystals(介晶) are a new class of nanostructured solid materials, which are most often made of crystallographically(晶向)oriented nanoparticles. Structural features, properties, and possible applications of mesocrystals are summarized in this paper. Due to their unique structural features a
2、nd the resulting physical and physicochemical properties, mesocrystals are expected to play a significant role in improving the performance of materials in many applications. These are as diverse as heterogeneous photocatalysts, electrodes, optoelectronics, biomedical materials, hard templates, and
3、lightweight structural materials.In the past 6 years, more and more attention has been paid to mesocrystalline materials. An increasing number of papers have been published in the literature. Most of these focused on the characterization of structures and the investigation of formation mechanisms. T
4、he results indicate that the structure and formation mechanism of a mesocrystal are related to the shape of the nanoparticle, colloidal stabilization, and vectorial long-range interaction potentials. Surface interaction between the nanoparticles plays a critical role during the formation process of
5、a mesocrystal and may be responsible for the formation of external faces. The reason for the remarkably (almost perfectly in some cases) ordered alignment of nanoparticles is still poorly understood. Special emphasis has been placed on the different possible forces that may drive orientation and ass
6、embly between nanoparticles.专业英语复试题-2This work describes the real-time and quantitative analysis of calcium phosphate mineralization using a quartz crystal microbalance (QCM) sensor and synthetic DNA templates. In typical mineralization studies, static end-point analysis and surface characterization
7、 is common, while real-time quantitation focusing on time of nucleation, nucleation rates, time of crystal growth, and growth rates has not been widely explored. A better understanding of these parameters in coordination with structural analysis could aid in the assessment of template molecules and
8、could provide insight into biological and biomimetic mineralization. QCM is a dynamic, real-time analytical technique that can be generalized to a variety of minerals and can be integrated with widely used surface characterization techniques. As a template for mineralization, DNA has only recently b
9、een studied, although it has potential as an anionic polynucleotide with unique programmability and structural diversity in folding.专业英语复试题-3Living organisms are well known to exploit the material properties of amorphous and crystalline minerals when building a wide range of organicinorganic hybrid
10、materials for a variety of purposes, such as navigation, mechanical support, photonics, and protection of the soft parts of the body. The high level of control over the composition, structure, size, and morphology of biominerals results in materials of amazing complexity and fascinating properties t
11、hat strongly contrast with those of geological minerals and often surpass those of synthetic analogues.1 It is no surprise, then, that biominerals have intrigued scientists for many decades and served as a source of inspiration in the development of materials with highly controllable and specialized
12、 properties. In this Review we aim to provide an overview of the different nature-drawn strategies that have been applied to produce materials for biomedical, industrial, and technological applications. We will first illustrate the diversity of biogenic minerals and their overall properties, and des
13、cribe the most general approaches used by organisms to produce such materials. We will then discuss several approaches inspired by the mechanisms of biomineralization in nature, and how they can be applied to the synthesis of functional and advanced materials such as bone implants, nanowires, semico
14、nductors, and nanostructured silica. In the final section, we will discuss methods that are necessary to study and visualize the formation of synthetic materials in situ so as to better understand, control, and optimize their synthesis and properties. 专业英语复试题-4Nanoparticles with dipole or magnetic m
15、oments will create local dipole/magnetic fields and can mutually attract each other in crystallographic register. The same is true for anisotropic particle polarization, where particle surfaces with equal polarizability attract each other by directed van der Waals forces. This concept requires the n
16、ucleation of a large number of nanoparticles of about the same size with the requirement of anisotropy along at least one crystallographic axis. This anisotropy can also be inherent to the crystal system as was observed for the case of amino acid crystals or might be induced by selective polyelectrolyte adsorption to expose highly charged faces simultaneously with their oppositely charged counterface. Amino ac
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