ZnO纳米线/棒阵列结构制备原理及方法概述

概述了ZnO纳米线/棒阵列结构的用途、制备原理和方法,重点介绍气相合成法和液相合成法中的几种典型制备ZnO阵列结构方法。展望了ZnO纳米线/棒阵列结构的发展方向及应用前景。     

ZnO纳米线阵列的图形化生长

采用光刻和射频磁控溅射技术在Si衬底上制备了图形化的ZnO种子层薄膜。分别采用气相榆运和水热合成法，制备了最小单元为30μm的图形化的ZnO纳米线阵列。X射线衍射（XRD）分析显示单晶纳米线阵列具有高度的c轴[001]择优取向生长性质，从扫描电子显微镜（SEM）照片看出，阵列图形完整清晰，边缘整齐，纳米线阵列在室温下光致发光（PL）谱线中在380hm左右具有强烈的紫外发射峰，可见光区域发射峰得到了抑制，证明ZnO纳米线阵列氧空位缺陷少，晶体质量高。     

紫外光刻法制备图案化聚合物纳米管/线阵列的研究

探讨了紫外光刻技术制备图案化聚合物纳米管/线阵列的方法,研究制备过程中的各种影响因素,并找到了最佳的实验条件。采用溶液浸润法,成功制备了不同图案的聚合物纳米结构阵列。溶液浓度为6%(质量分数),得到的是聚合物纳米管阵列;溶液浓度为10.0%(质量分数),得到的是聚合物纳米线阵列。     

基于ZnO纳米线阵列的真空压强传感器

首先用化学气相沉积法制备了ZnO纳米线阵列,然后在此基础上制作了真空压强传感器。测试了基于ZnO纳米线阵列的真空压强传感器敏感特性,并与基于ZnO纳米带膜的传感器敏感特性做了比较,发现前者比后者敏感特性更好,相比传统的真空传感器,具有测量范围宽、灵敏度高和功耗低等优点。这主要是由于ZnO纳米线阵列具有较大的比表面积及氧吸附与解吸附等原因引起。     

CuO/ZnO复合纳米树阵列的制备及光学特性

通过热氧化法在铜基板上制备CuO纳米线,采用凝胶法制备ZnO/CuO复合纳米树阵列。通过扫描电镜(SEM)、X射线衍射(XRD)、光致发射光谱对样品结构、形貌、光学特性进行表征。结果表明,CuO/ZnO纳米树形貌规整完美,在CuO纳米线上二次生长的ZnO纳米棒具有各向晶体生长性质,CuO/ZnO复合纳米树在可见光区域出现了优越的发光性能;以甲基橙为模拟污染物,通过光催化测试表明,CuO/ZnO复合纳米树还具有卓越的光催化性能。     

ZnO/TiO_2复合纳米材料的制备及其在染料敏化太阳电池中的运用

本文在长有ZnO纳米粒子作为"种子层"的FTO基底上用水热合成法制备了取向高度一致的ZnO纳米线阵列,用TiCl4的异丙醇溶液在ZnO纳米线阵列的表面生长了纳米结构的TiO2。利用扫描电子显微镜、能量散射谱、X射线衍射分别表征纳米材料的形貌和结构,用Raman光谱研究了材料的晶格结构特性。染料敏化太阳电池的性能测试表明,与纯ZnO作为光阳极相比,ZnO/TiO2复合纳米材料作为光阳极的器件,开路电压和填充因子都得到了提高。     

纳米线阵列及纳米图形制备技术的研究进展

当今纳米技术研究的前沿和热点之一是将纳米线按一定方式排列与组装构成纳米线阵列及纳米图形,它们是下一代纳米结构器件设计的材料基础,在激光技术、信息存储及计算技术、生物技术等各领域均有广阔的应用前景.介绍了在纳米线阵列材料制备以及纳米图形制作方面的技术研究进展,详述了模板法、自组装法以及纳米刻蚀法等技术的发展.     

恒流法制备图案化的阳极氧化铝模板

采用紫外线光刻技术在铝片上生成预设图案,用恒流二次氧化法在图案化的铝片上生长AAO,以此模板制备了PS和Cu纳米线阵列.采用扫描电子显微镜(SEM)分析.结果表明,制备的图案是直径5μm的圆形组成,圆形图案中·心之间距离是10μm,每个圆中生长了均匀的AAO,孔径大约为60～80nm.     

新型纳米功能材料

讨论了纳米材料复合薄膜的结构和特性,涉及到与力学、防护、电池等特性有关的结构,重点分析了电学、光学、光电特性,如新型纳米线复合光电池,氧化锌(ZnO)纳米棒阵列的结构和荧光发射,以及金属纳米线阵列的制备和场发射特性.金属纳米线阵列场发射的高分辨,结构完美,工艺简单和极低的成本,有可能是未来平板显示器的重要组件.     

ZnO纳米线阵列修饰对材料表面浸润性调控

采用溶胶-凝胶法制备了ZnO薄膜,利用溶剂热沉积法获得大面积均匀ZnO纳米线阵列。通过对水在ZnO材料表面的浸润性研究,发现薄膜材料表面的粗糙度对ZnO膜亲水性有增强作用,而周期性ZnO阵列微结构表面可以实现其疏水性质增强效果。同时从理论上分析了这两种现象的物理机制,讨论了空气填隙对ZnO纳米线阵列表面的浸润性质的敏感性。制备出ZnO纳米线阵列的表观接触角约为103°,具有较强的疏水性质,可为进一步的ZnO光流控研究提供实验基础。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.