热丝CVD大面积金刚石薄膜的生长动力学研究

在传统工业型热丝化学气相沉积（HFCVD）反应腔内，相关工艺参数取模拟计算优化值的条件下，采用XRD，SEM及Raman光谱等分析手段研究了单晶Si（100）上较大面积金刚石薄膜的动力学生长行为，讨论了晶格取向的变化规律。结果表明：优化工艺参数条件下，在模拟计算的衬底温度和气体温度分布均匀的区域内，沉积的金刚石薄膜虽存在一定的内应力，但整体薄膜连续、均匀，几何晶形良好，质量较高，生长速率达1．8μm／h。薄膜生长过程中晶形显露面受衬底温度和活性生长基团浓度的影响较大。     

立方结构PbSe薄膜在六角硒化镉单晶（0001）表面的外延生长研究

采用分子束外延技术在六角铅锌矿结构CdSe单晶基片 (0001) 表面生长了立方结构PbSe薄膜, 通过对所生长PbSe薄膜的X射线衍射 (XRD) 及透射电镜 (TEM) 分析, 阐明了所生长立方PbSe薄膜与六角纤锌矿结构CdSe (0001) 的外延关系, 高分辨率TEM分析结果显示:CdSe基片与PbSe薄膜之间界面清晰, PbSe薄膜的晶体结构完整, 其电子衍射谱的各级衍射斑点无明显畸变;XRD分析结果显示:所生长立方PbSe薄膜为 (100) 取向, PbSe薄膜与CdSe单晶的面内外延关系为PbSe[110]//CdSe[100], 并呈现出三种不同面内取向晶粒镶嵌排列的微观结构, 这表明:虽然六角铅锌矿结构CdSe (0001) 面与立方PbSe (100) 面具有不同的对称性, 但仍能生长出高质量的PbSe薄膜, 并为PbSe薄膜的应用奠定了可能。     

与基片位置有关的不同夹具下生长的薄膜结构模拟与分析

按照正切规则，给出了不同夹具下与基片位置有关的薄膜微柱体的生长公式，并直 观地模拟计算了这些薄膜的微观结构，反映了不同夹具下生长的薄膜结构差异与特点。     

异质外延MgO/SrTiO3薄膜中界面应力研究

本文利用激光分子束外延(LMBE)技术在SrTiO3(100)单晶基片上外延生长MgO薄膜，同时又在MgO(100)单晶基片上外延生长SiO3(STO)薄膜。通过反射高能电子衍射(RHEED)仪原位实时监测薄膜生长，研究薄膜的生长过程。并结合X射线衍射(XRD)仪来分析在不同的生长条件下，不同应力对薄膜外延生长的影响。在压应力情况下，MgO薄膜在STO基片上以单个晶胞叠层的方式生长，即以“Cubicon Cubic”方式进行外延；在张应力情况下，由于膜内位错较多，STO薄膜在MgO基片上以晶胞镶嵌的方式进行生长，即以“Mosaic”结构进行外延；提高生长温度，可以减少膜内位错，提高外延质量，使STO薄膜在MgO基片上以较好的层状方式外延生长。     

原位退火处理对ZnS/Si薄膜结晶性能的影响

采用脉冲激光沉积法在Si衬底上生长出厚度为400nm的一系列ZnS薄膜,进行原位退火处理,获得单晶结构的闪锌矿型ZnS薄膜。首次报道了采用原位退火处理后获得单晶ZnS薄膜为立方结构的闪锌矿且薄膜沿(111)晶面择优生长,同时研究了其结晶质量与退火工艺之间的关系。结果显示随着退火温度的升高,薄膜的平均晶粒尺寸由200℃的13.357nm增长到400℃的27.232nm,另外薄膜的平均粗糙度由2.05nm下降达到1.14nm。采用脉冲激光沉积法制备的ZnS薄膜在400℃退火后表现出极好的单晶择优取向生长以及良好的表面平整度,为研究单晶ZnS薄膜提供一种实验解决思路。     

溅射功率对Ca2Si薄膜性质的影响

采用射频磁控溅射技术在Si（100）衬底上沉积了si-ca-si薄膜，并在高真空条件下对样品进行退火处理，直接生成立方相Ca2Si薄膜。研究了不同溅射功率对薄膜的晶体结构、表面（断面）形貌的影响，并对其光学性质进行了测试分析。结果表明：Ca2Si薄膜为立方结构且具有沿（111）向择优生长的特性，当溅射功率为120W时，Ca2Si薄膜变的均匀、致密，在400-800nm波长范围内，溅射功率对折射率n和吸收系数k的影响较小。     

真空气相沉积可控制备有机半导体单晶薄膜

利用多温区温度可控的真空气相沉积设备,在热氧化硅片衬底上沉积了并五苯（PEN）与甲氧基寡聚苯乙烯撑（MOPV）2种有机半导体材料的薄膜。研究了不同的沉积条件下有机半导体材料在二氧化硅衬底上的成核和生长模式。MOPV的生长遵循Volmer-Weber模式。在理想的条件下分别得到了岛状与线状的单晶结构。偏振显微荧光研究证明单晶纳米线有显著的荧光各向异性。     

Si(111)衬底上生长的立方MgxZn1-x晶体薄膜

在国际上第一次采用电子束反应蒸发法在Si(111)衬底上生长了MgxZn1-xO晶体薄膜。能量色散X射线(EDX)特征能谱及X射线衍射(XRD)分析表明薄膜呈立方结构，薄膜的晶面取向依赖于生长温度，在200℃温度下生长得到高度(200)取向的立方MgxZn1-xO薄膜，温度过高时得到多晶薄膜。对高度(200)取向的立方MgxZn1-xO薄膜的光荧光激发谱(PLE)分析表明其光学带隙为4．20eV，相对于MgO的带隙红移量为3．50eV。XRD分析还表明立方MgxZn1-xO薄膜与MgO衬底之间的晶格失配仅为0．16％。这使得高质量立方MgxZn1-xO多量子阱材料的制备成为可能。     

掺Sb—CdTe薄膜的结构及其光学特性研究

用真空蒸发技术在玻璃衬底上获得了掺Sb的CdTe薄膜，薄膜为立方晶系结构，具有沿[111]晶向的择优取向。薄膜为P型呈高阻状态，在可见光范围内透过率很低。研究了不同掺杂浓度下薄膜的性质，并在不同条件下对薄膜，进行热处理，研究了蒸处理对薄膜的影响。     

离子注入条件下单晶银薄膜形成的理论探讨

在室温环境下，用不同的注入剂量将２４ｋｅＶ的Ｎ＋离子和３５０ｋｅＶ的Ｘｅ＋离子注入进多晶银薄膜中。对实验结果进行分析后发现，经离子注入后在银薄膜中出现了再结晶和晶粒长大现象。当注入的离子达到一定剂量时，多晶银薄膜转变成单晶银薄膜．本文对单晶银薄膜的形成机理作了探讨，认为与晶粒生长有关的主要因素是：（１）离子注入．过程中在薄膜内部产生的高密度的缺陷和位错促进了晶粒再结晶和晶粒生长。（２）由于晶格畸变而产生的界面张力为在晶粒初始再结晶以后的进一步长大提供了驱动力。（３）晶粒之间的取向差有助于晶粒的生长。（４）离子注入过程中产生的晶格弛豫效应促使薄膜中的应变能不断恢复和产生，使晶粒持续不断地再结晶而逐渐长大。（５）薄膜的基底对单晶薄膜的形成有一定影响。     

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.     

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.……     

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 ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.