关键词： Rare earths   Lanthanides   Recycling   Extractive metallurgy   Magnets   Catalysts   BatteriesPreview | Abstract | Full Text | PDF (449 KB) | FiguresNovember 18   2013G A MoldoveanuG A Moldoveanu   V G PapangelakisV G PapangelakisMoldoveanuMoldoveanu   PapangelakisPapangelakisMoldoveanu et al.Moldoveanu et al.Leaching of lanthanides from various weathered elution deposited oresLeaching of lanthanides from various weathered elution deposited oresG A MoldoveanuG A Moldoveanu   V G PapangelakisV G PapangelakisMoldoveanuMoldoveanu   PapangelakisPapangelakisMoldoveanu et al.Moldoveanu et al.Volume: 52   Issue: 3   pp. 257–264http://***/10.1179/1879139513Y.0000000060Keywords: Ion adsorption clays   Rare earths leaching   Rare earths desorption   Ion exchange leaching   Lanthanides   Rare earth elements Preview | Abstract | Full Text | PDF (314 KB) | FiguresNovember 18   2013D K ChibweD K Chibwe   G AkdoganG Akdogan   C AldrichC Aldrich   P TaskinenP TaskinenChibweChibwe   AkdoganAkdogan   AldrichAldrich   TaskinenTaskinenChibwe et al.Chibwe et al.Modelling of mixing   mass transfer and phase distribution in a Peirce–Smith converter modelModelling of mixing   mass transfer and phase distribution in a Peirce–Smith converter modelD K ChibweD K Chibwe   G AkdoganG Akdogan   C AldrichC Aldrich   P TaskinenP TaskinenChibweChibwe   AkdoganAkdogan   AldrichAldrich   TaskinenTaskinenChibwe et al.Chibwe et al.Volume: 52   Issue: 2   pp. 176–189http://***/10.1179/1879139512Y.0000000056Keywords: Computational fluid dynamics   Peirce–Smith converter   ModellingPreview | Abstract | Full Text | PDF (536 KB) | FiguresNovember 22   2013D K ChibweD K Chibwe   G AkdoganG Akdogan   C AldrichC Aldrich   P TaskinenP TaskinenChibweChibwe   AkdoganAkdogan   AldrichAldrich   TaskinenTaskinenChibwe et al.Chibwe et al.Modelling of mixing   mass transfer and phase distribution in a Peirce–Smith converter modelModelling of mixing   mass transfer and phase distribution in a Peirce–Smith converter modelD K ChibweD K Chibwe   G AkdoganG Akdogan   C AldrichC Aldrich   P TaskinenP TaskinenChibweChibwe   AkdoganAkdogan   AldrichAldrich   TaskinenTaskinen  

摘要： Polycrystalline materials are visualized in this paper as a statistical ensemble of microelements whose crystallographic axes are randomly, but not uniform randomly, oriented in the material system. Based on this concept the influence of internal dislocations and grain boundaries on the elastic response of such metals is discussed. The latter influence is taken into consideration by combining the grain boundary coincidence cell models of Bollmann with the relaxation technique of Weins in the case of symmetric tilt boundaries. The micromechanics theory of Axelrad and Provan is also briefly discussed to indicate where these quantitative metallurgical studies are of importance in the further development of this theory. Résumé Dans cette étude, les matériaux poly cristallins sont considérés comme un ensemble statistique de micro-éléments dont les axes cristallographiques sont orientés au hasard, mais non uniformément, dans le matériau. A partir de ce concept, les auteurs discutent de l'influence de dislocation et des joints de grains sur la réponse élastique de tels métaux. L'influence des joints de grains est considérée en combinant le modéle des sites en coincidence de Bollmann avec la technique de relaxation de Weins, pour le cas des joints de flexion symétriques. La théorie de la micromécanique de Axelrad et Provan est aussi brièvement discutée pour indiquer quelles sont les études métallurgiques quantitatives nécessaires au développement ultérieur de cette théorie.

摘要： Polymer nanocomposites (PNCs) represent a radical alternative to conventional filled polymers or polymer blends. In contrast to conventional composites, where the in- cluded phase is on the order of micrometers, PNCs are defined as those that have discrete constituents on the order of a few hundred nanometers. The value of PNCs is not solely based on tailoring mechanical properties, as in traditional composite design and manufacture, but rather on the potential for the design and optimization of multi-functional properties. There is major interest in these polymeric materials embedded with a conductive nanoscale filler. This is due to the possibility of design- ing a composite that retains the easy processing of plastics but can take advantage of a conductive nanoscale phase; providing electrical conductivity in additional to structural reinforcement. The challenge to modeling multi-functional properties of PNCs is that, tradition- ally, different models have been applied to model different properties. Mechanical properties are most often modeled using mean-field models from micromechanics; properties depend on the microstructural arrangement of the included phase, phase properties and volume fraction. Electrical conductivity has primarily been modeled using percolation theory and power-law models; properties depend on theoretical or simulation based estimates of a percolation threshold, phase properties and volume fraction. However, models of both properties should ideally be built on specific mi- crostructural descriptions as well as include a probabilistic framework to capture percolation effects. In this work a modeling framework, developed for predicting composite mechan- ical properties, is investigated for its applicability in modeling effective electrical composite properties. The basis for using a micromechanics approach for predictions of conductivity is presented as well as how the model is adapted to model conductiv- ity. A comparison of the adapted and

关键词： 纳米   拉曼光谱   均方根键角畸变   平均键畸变能   Nano-material   GaP   Gallium Phosphide   Raman Spectra   Root mean square bond angle distribution   Mean stored energy  

摘要： 利用纳米GaP固体材料拉曼光谱的类横向光学模峰移(ΔωTO)对其均方根键角畸变(Δθ)和平均键畸变能(Uθ)进行了计算.计算结果表明:当成型压力增加时,纳米GaP固体材料的Δθ和Uθ均增加;而将纳米GaP固体材料在325℃进行1h热处理后,其Δθ和Uθ并没有明显的变化.关键词

关键词： 微机电器件   红外光谱   纳米级   石墨微结构   MEMS device   infrared spectroscopy   nanoscale   graphite microstructure  

摘要： 具有原子级光滑平面的石墨平台微结构是实现特殊功能微机电器件、微系统的重要基础。石墨微结构的化学信息表征对微机电器件、微系统的制备及性能有着重要的意义。先使用原子力显微镜获得形貌信息，再使用纳米级红外光谱对微结构的不同区域进行表征，获得了多个特征位置的红外光谱。通过对红外光谱的分析发现相对于其他位置，石墨平台表面具有非常有序的碳六元环结构，并且吸附的水分子最少。而石墨平台微结构的边缘由于悬键及微加工等原因是吸附水分子最多的位置，石墨基底由于微加工的破坏已经不具有碳六元环结构。这些信息为了解微结构的化学状态提供了帮助，明确所处环境对石墨平台微结构不同位置的影响，能够指导微机电器件的制备与应用。关键词

关键词： 微晶玻璃   氧化亚铜纳米晶   显微结构   抗菌性能   可见光催化   glass-ceramics   Cu2O nanocrystalline   microstructure   antibacterial property   visible light driven photocatalysis  

摘要： 新型Cu2O纳米微晶玻璃具有高Cu载量、低成本和易大规模制备等特点，有望成为载银抗菌玻璃较有潜力的替代者。通过采用XRD、Raman光谱、XPS、FESEM和TEM等表征方法重点研究了不同ZnO/K2O比对SiO2-Al2O3-K2O-ZnO-P2O5-B2O3-CuO微晶玻璃显微结构的影响，并分析讨论了其结构-性能关系。结果表明，微晶玻璃中Zn与P元素会富集在Cu元素所在区域的附近，适量的ZnO能使微晶玻璃中析出的Cu2O晶粒尺寸稳定在纳米级别，并能调节微晶玻璃中Cu元素的浸出速率。Cu2O纳米微晶玻璃对大肠杆菌和金黄色葡萄球菌均具有显著的抗菌效果，并能实现对维多利亚蓝B溶液的可见光催化降解，是一种极具发展潜力的新型功能微晶玻璃材料。

关键词： 溶剂交换   异丙醇   丙酮   甲醇   乙醇   微结构   solvent exchange   isopropanol   acetone   methanol   ethanol   microstructure  

摘要： 溶剂交换法广泛应用于水泥基材料的干燥和终止水化中。本文综述了溶剂交换对水泥浆体显微结构的影响。阐述了交换参数(样品尺寸、液-固比、交换时间和去除方法)的选取原则。重点论述了常见交换溶剂(异丙醇、丙酮、甲醇和乙醇)与水泥水化产物(氢氧化钙、水化硅酸钙和钙矾石)之间存在的物理化学反应。在交换参数和溶剂的影响下，对比分析了水泥基材料的孔结构参数(孔隙率和孔径分布)。最后提出了溶剂交换方法目前存在的问题及研究展望。

摘要： 卤化物,特别是KCl被认为是高功率激光窗口最佳候选材料。为了研究热锻KCl的显微结构稳定性,用化学浸蚀法显示了晶粒间界并用光学显微镜进行了观测。在KGl多晶中发现有重结晶不完全、二次再结晶、不均匀的显微结构及室温下晶粒长大等现象。关键词

关键词： 锂离子电池   正极材料   微结构   掺杂   高镍   lithium ions battery   cathode materials   microstructure   doping   nickel rich  

摘要： 电动汽车等应用领域对锂离子电池能量密度的需求日益增长，LiNi0.9Co0.1O2因其高比容量和价格适中等优势受到了广泛的关注，有潜力成为下一代锂离子电池正极材料。然而，锂镍混排、H2-H3相变引起的微裂纹和表面副反应等问题导致LiNi0.9Co0.1O2的充放电循环稳定性较差。通过掺杂W6+对LiNi0.9Co0.1O2的微结构进行了有效调控，并调节一次晶粒的表面能使其由无序堆积的不规则形状转变为径向有序排列的细长条状。该微结构特征可以抑制LiNi0.9Co0.1O2的应力累积和微裂纹的形成，同时为Li+提供了丰富的扩散通道，有效提高了LiNi0.9Co0.1O2正极材料的循环稳定性和倍率性能。当W6+掺杂量为1% (摩尔分数)时，LiNi0.9Co0.1O2改性样品在0.1 C倍率下的放电比容量高达231.2 mA·h/g，在0.5 C倍率下放电比容量为213.3 mA·h/g，循环150次后容量保持率达93%。该微结构调控策略为提高LiNi0.9Co0.1O2高镍正极材料的循环稳定性提供了一种思路。关键词

关键词： 纳米结构   原位研究   电子显微学  

摘要： 利用电子显微学方法原位研究了外场作用下纳米材料的微结构稳定性,进行了微结构修饰和纳米材料间联结.结果显示外电场使多壁碳纳米管端部碳原子间的π键分解,外部碳原子与端部碳原子结合形成σ键.在端部电场的作用下,外部碳原子定向生长成非晶态碳纳米线,形成碳纳米管一纳米线复合结构.采用电子束诱导沉积的方法对二个多壁碳纳米管端部之间进行了焊接,实现了纳米材料间的几乎无损伤的联结.电子显微镜作为新纳米结构构建工具有位置选择精确、可实时监测、对纳米材料几乎无损伤、重复性和可靠性高,以及加工尺度可人为控制的优点.关键词

摘要： Semiconductor nanowires (NWs) are anticipated to play a crucial role in future electronic and optoelectronic devices. Their practical applications remain hindered by an urging need for feasible strategies to tailor their optical and electronic properties. Strategies based on strain and alloying are limited by issues such as defects, interface broadening and alloy scattering. In this thesis, a novel method to engineer the optoelectronic prop- erties based on strain-free periodic structural modulations in chemically homogeneous Nanowire Twinning Superlattices (NTSLs) is experimentally demonstrated. NTSLs are an emerging new class of nanoscale material, composed of periodically arranged rotation twin-planes along the length of NWs. The main objective of this thesis is to establish the relationship between the electronic energy band gap (E g ) and the twin-plane spac- ing (d) in NTSLs, quantified using a periodicity parameter, based on ZnSe. ZnSe was chosen because of its excellent luminescence properties, and potential in fabrication of optoelectronic devices in the near-UV and blue region of the spectrum. A prerequisite to establishing this correspondence is a prior knowledge of the photolu- minescence (PL) response and the nature of fundamental optical transitions in defect-free single crystal ZnSe NWs with ZB and wurtzite (WZ) crystal structures. There has been no systematic work done yet on understanding these fundamental optical processes, par- ticularly on single NWs and in relation to their crystalline microstructure. Therefore, the secondary objective of this thesis is to study the influence of native point defects on the optical response of single ZnSe NWs in direct relation to their crystalline microstructure. The PL response from single ZB and WZ NWs was determined unambiguously, and excitonic emission linewidths close to 1 meV were observed, which are the narrowest reported linewidths thus far on ZnSe NWs. Based on this and extensive optical and structural