氩气氛下制备的C60薄膜的形貌、结构和光学性质

用原子力显微镜（AFM）、X射线衍射（XRD）、红外光谱（IR）及紫外－可见光谱（UV／VIS）研究了在氩（Ar）气氛下制备的C60薄膜的表面形貌、结构及光吸收特性。发现其UV／VIS的强度和吸收峰位置明显不同于在真空中制备的C60薄膜。与真空中制备的C60薄膜比较,所研究薄膜的红外谱没有变化,但X射线衍射表明其结构从面心立方（fcc)相变成fcc相与六角密堆（hcp)相的混合相。AFM表明,在Ar气氛中制备的C60薄膜有较大的表面粒子,并且表面生长岛更尖锐。这将有利于C60薄膜的场电子发射。     

MgxZn1-xO薄膜的结构特性研究

采用射频磁控溅射法在80℃衬底温度下制备了MgxZn1-xO（x=0．23）薄膜，用X射线衍射（XRD）、高分辨透射电镜（HRTEM）、喇曼（Raman）光谱和原子力显微镜（AFM）研究了薄膜的结构特性．XRD和HRTEM分析结果表明MgxZn1-xO薄膜为单相六角纤锌矿结构，且具有沿c轴的择优取向，晶格常数与ZnO晶体的近似相等．Raman光谱不仅揭示MgxZn1-xO薄膜具有六角纤锌矿结构，而且也表明MgxZn1-xO薄膜的结晶质量比在相同条件下制备的ZnO薄膜好．AFM图像则显示出MgxZn1-xO薄膜为多晶结构．     

温度对PTCDA结构形貌影响的Raman和AFM分析

通过真空蒸发将PTCDA淀积在p-Si(100)面.采用Raman光谱,AFM分别研究了衬底温度对于PTCDA分子结构和表面形貌的影响,进而完善了p-Si基PTCDA薄膜的生长机制.     

功率和温度对a-C:F:H膜表面形貌和结构的影响

分析薄膜的表面形貌对其生长机理和光学性质研究有着十分重要的作用。本文使用CF4和CH4为源气体，利用射频等离子体增强化学气相沉积（RF—PECVD）法在不同射频功率和沉积温度下制备了掺氟氢化无定形碳（a—C：F：H）薄膜，并在N2气氛中进行了不同温度的退火处理。用原子力显微镜（AFM）和扫描电子显微镜（SEM）观察了薄膜表面形貌，发现低功率下沉积的薄膜表面均匀性好、缺陷少；在低温下沉积的薄膜表面光滑，而高温下粗糙；真空低温退火可使薄膜表面形貌得到改善，但薄膜内空洞增加，退火温度过高，薄膜的结构发生变化，且在薄膜表面发生皲裂现象。用Raman光谱对薄膜内的结构变化进行了进一步的分析。     

以Al2O3为过渡层脉冲激光法制备PZT铁电薄膜

为实现PZT铁电薄膜与半导体衬底的直接集成引入Al2O3为过渡层，首先用真空电子束蒸发法在Si(100)，多昌金刚石（111）衬底上生长约20nm厚的Al2O3过渡层，接着在上述衬底上采用脉冲激光淀积（PLD）法淀积PZT薄膜，衬底温度为350-550℃。X光电子能谱（XPS）测试表明，在高真空下，电子束蒸发Al2O3固态源能获得化学配比接近蒸发源的Al2O3薄膜。X射线衍射（XRD）测试说明，不论衬底是硅还是多晶金刚石，当衬底温度为550℃时，PZT在Al2O3过渡层上呈现（222）取向的焦绿石相结构，当衬底是金刚石时，通过如下工艺：（1）较低温度（350℃）淀积；（2）空气氛围650℃快速退火5min，可以在Al2O3过渡层上获得高度（101）取向的钙钛矿结构的铁电相PZT薄膜，最后AFM测试显示，在硅衬底上，PZT薄膜的表面均方根粗糙度为9.78nm；而在多晶金刚石衬底上，PZT薄膜的表面均方根粗糙度为17.2nm。     

纳米晶粒受控生长抑制PZNT铁电薄膜中异相形成

在LaAlO3（001）、MgO（001）、SrTiO3（001）衬底以及SrTiO3（001）／PZT（001）种膜上用液相外延方法生长了PZNT薄膜。生长结果表明：在LaAlO3（001）基片PZNT晶粒以三维岛状自发生长。薄膜中有大量的焦绿石异相；在MgO（001）和SrlriO3（001）衬底上，为三维岛状异质外延生长。薄膜中焦绿石异相几乎消失；引入[001]取向的PZT种膜后，岛状三维生长变为二维生长，显著改善了外延膜的质量，获得了完整的PZNT膜。分析了衬底取向对紧邻层纳米尺寸范围的晶粒形成、薄膜晶粒的发育、克服薄膜中异相形成等的影响，总结了获得完整PZNT薄膜的生长条件。     

改进溶胶-凝胶法制备PZT5O/5O铁电薄膜

采用改进的溶胶-凝胶法在Pt/Ti/SiO2/Si衬底上制备了PZT50/50铁电薄膜，用X射线衍射表征了薄膜的物相，用原子力显微镜（AFM）表征薄膜的微观形貌，用RT-66A测量了薄膜的铁电特性，获得了具有优良的铁电性能的晶粒尺寸为100nm的PZT50/50铁电薄膜，在20V电压下，Pr=31.83uC/cm^2。     

常压化学气相沉积方法制备非晶硅薄膜及其光致发光性能研究

使用改进的常压化学气相沉积(APCVD)系统制备了非晶硅薄膜,测量了样品的光致发光特性,使用Raman光谱和X射线光电子能谱(XPS)谱测量了薄膜的微结构特征.样品在523 nm出现发光峰,Raman光谱和XPS谱表明制备的薄膜结构中存在富氧相和富硅相的分相现象,分析认为相界面的存在是产生发光的原因.Raman光谱分峰结果表明薄膜中存在纳米晶粒.     

类金刚石薄膜的紫外辐照研究

对射频等离子体方法制备的类金刚石（以下简称DLC）薄膜样品进行了紫外辐照，采用电阻率，Raman光谱及红外光谱研究了紫外光（以下简称UV）辐照对DLC薄膜结构与特征的影响，Raman光谱表明：紫外光对DLC薄膜中SP^3C-H键的破坏作用非常明显，红外（IR）光谱结果进一步验证了这一结果，经UV辐照后，DLC薄膜的电阻率呈变小趋势，这说明薄膜被强烈氧化，最后呈现石墨化趋势。     

MOD制备的PZT薄膜的相结构发展和成分分析

采用MOD工艺制备了PZT薄膜,利用XRD和TEM研究了焦绿石相向钙钛矿相的转变过程．制备在Pt／Ti／SiO₂／Si衬底上的PZT薄膜,其XRD分析显示焦绿石相在600℃完全转变为钙钛矿相;与之相比,Pt箔上无支持的PZT薄膜,其TBM分析表明PZT焦绿石相完全转变为钙钛矿相的温度更高,且与薄膜的厚度有关．XPS研究表明,薄膜表面含有化学吸附氧和污染碳,无其它杂质存在.表面富含少量Pb,其Zr／Ti比与化学计量比一致,但晶格中缺氧．     

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.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...