使用SPM的纳米级加工技术新进展

扫描探针显微镜(SPM)现在不仅用于表面微观形貌的检测，同时也用于纳米超精密加工和原子操纵，该文介绍了用STM和AFM进行纳米级加工的各种最新方法：针尖直接雕刻，针尖光刻加工，局部阳极氧化，原子沉积形成纳米点，原子去除形成沟槽微结构，多针尖加工，原子自组装形成三维结构等．使用SPM的纳米级加工对发展微型机械、纳米电子学和微机电系统具有重要意义．     

有机功能薄膜的超高密度信息存储

超高密度信息存储研究是纳米电子学的重要研究领域,有机功能薄膜以其独特的性质有可能成为超高密度信息存储介质之一。利用ＳＴＭ研究了Ｎ,Ｎ－二甲基－Ｎ－（３－硝基苯叉）－对苯二胺（ＤＭＮＢＰＤＡ）有机薄膜的存储特性。高分辨扫描电子显微镜的结果表明,在扫描过程中ＳＴＭ对ＤＭＮＢＰＤＡ薄膜表面进行了二次加工,显微Ｒａｍａｎ谱表明在加工区依然存在着ＤＭＮＢＰＤＡ薄膜,并用原子力显微镜表征了加工区薄膜的表面形貌     

聚丙烯薄膜的表面结构与驻极体性能相关性研究

以聚丙烯颗粒为原料、表面纳米化石英玻璃为模板,通过热压法制得表面具有不同形貌的聚丙烯薄膜,再经电晕充电形成驻极体。采用原子力显微镜技术分析了薄膜的表面结构,并用表面电位跟踪和热刺激放电技术测试了不同表面结构聚丙烯薄膜的电荷存储性能。表面电位测试结果表明,其电荷存储性能与薄膜表面的微观结构密切相关,薄膜表面越粗糙,捕获电子的能力越强,但其电荷存储稳定性差异不大。热刺激放电技术测试结果表明,其陷阱能级与表面粗糙度无关。     

Mg中间层对纳米钛表面TiO2薄膜微结构和动态凝血时间的影响

采用直流磁控溅射技术在纳米钛表面沉积Mg/TiO_2双层薄膜,研究了Mg中间层对纳米钛表面TiO_2薄膜微结构、动态凝血时间和界面结合力的影响。结果表明,Mg中间层对纳米钛表面TiO_2薄膜微结构、动态凝血时间和界面结合力有显著影响。预制Mg中间层后,纳米钛表面TiO_2薄膜由金红石相(含少量锐钛矿)转变为MgTiO_3、Ti_2O_3和少量金红石相;纳米钛表面TiO_2薄膜沿Mg膜晶界生长成微米级团簇,而团簇内部具有纳米畴特征;纳米钛表面TiO_2薄膜的凝血时间由17 min提高到40 min;纳米钛表面TiO_2薄膜的界面结合力由17N提高到36 N。     

STM研究光盘材料结构转变前后表面形貌的分形维数

采用ＳＴＭ在纳米尺度上对光盘材料结构转变前后表面微观形貌进行了研究，ＳＴＭ结合图象处理和傅利叶分析法可以较好地用于研究薄膜表面形貌的分形特征，用电子束蒸发制备的无定形态记录介质薄膜表面形貌在纳米尺度上呈现出分形特征，经加热晶化后介质薄膜发生结构转变，表面形貌的分形维数增加。     

基于SPM的纳米计量中若干重要问题

扫描探针显微镜(SPM)由于具有纳米甚至原子量级的分辨率,20多年来已引起各个领域科学家们的广泛兴趣。在精密工程领域,它作为一种极具前途的纳米计量工具,已在许多国家受到了广泛的重视,如美国NIST,德国PTB和英国NPL等都相继开展了基于SPM的纳米计量技术研究。但作为纳米级的计量分析仪器,不仅要有高分辨率,更要有纳米级甚至更高的精度。     

生长温度对纳米AlN薄膜的表面形貌和结晶特性的影响

采用射频(RF)反应磁控溅射方法制备了具有原子级平滑表面的纳米AlN薄膜。利用傅立叶红外光谱(FTIR)、透射电子显微镜(TEM)、原子力显微镜(AFM)、卢瑟福背散射(RBS)等分析方法对不同实验条件下合成的AlN薄膜进行了表征，研究了不同沉积温度(室温约550℃)下的AlN薄膜的表面形貌特征和结晶特性，探讨了AlN薄膜表面形貌的变化规律及纳米薄膜的形成机制。分析结果显示：不同沉积温度下合成的AlN薄膜均具有原子量级平滑的表面，薄膜表面粗糙度(RMS)为0．2～0．4nm，且不随沉积温度的增加而发生明显变化；薄膜的晶粒尺度为20～30nm，薄膜的折射率随沉积温度的增加而增加。     

自组装纳米超薄膜研究进展及其应用

纳米超薄膜指薄膜厚度处在纳米数量级的薄膜。纳米级超薄膜具有导电、电致发光、光电转换等多种功能，可用于制备传感器、太阳能电池以及光通讯元件，近年来受到广泛重视。自组装是制备多层纳米超薄膜的一种方法，它制备的超薄膜是高度有序和具有方向性的超薄膜。本文就自组装制备纳米超薄膜技术的发展进行了详细的介绍，并对纳米超薄膜的应用发展进行了探讨。     

非织造材料表面生长ZnO薄膜的特性研究

室温下采用射频磁控溅射技术在涤纶纺粘非织造材料表面生长ZnO薄膜。通过扫描电子显微镜及原子力显微镜对ZnO薄膜的微观结构进行表征,用分光光度计测量样品的透光率。结果表明,ZnO薄膜为纳米级,其平均晶粒大小约为30 nm~55 nm。生长了ZnO透明纳米结构的非织造材料对紫外光有较强的吸收能力,在可见光区的透光率达60%以上。     

直流热阴极PCVD法掺氮纳米金刚石薄膜形貌及结构的影响

采用直流热阴极等离子体化学气相沉积(PCVD)技术,通过在CH4/H2的混合反应气源中通入不同流量的N2,合成了掺氮纳米金刚石薄膜。结果表明随着氮气流量的增加,金刚石薄膜表面形貌发生明显变化:晶粒细化,晶界和缺陷有所增多,膜层由尺寸较大微晶颗粒转向纳米级菜花状结构,并且薄膜表面粗糙度相应变小。同时薄膜中非金刚石组份相对逐渐增多。氮气的引入可以促进金刚石二次形核,抑制金刚石大颗粒生长,对薄膜的生长取向、形貌及结构都产生一定影响。     

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.     

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.     

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.……     

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.……     

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.     

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.     

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.