高锡含量锗锡合金和镍反应的形貌研究

本文详细研究了高锡含量锗锡合金(Ge_(0.92)Sn_(0.08))与镍在退火条件下的反应。通过表层电阻测试、原子力显微镜和透射电镜等表征手段,我们分别研究了镍锗锡材料在300℃、400℃、500℃温度下退火后的表面和界面形貌。研究表明:与镍和锗反应相比,镍和锗锡材料反应生成的镍锗锡薄膜热稳定性变差,退火温度400℃后镍锗锡薄膜表层电阻就迅速增加,样品表面变得不连续,团聚为平均长度200nm左右的岛状晶粒,样品表面和界面与电学性质都遭到了破坏。     

氢气氛退火对硅上低温外延制备的硅锗薄膜性能的影响

采用反应型热化学气相沉积系统在硅(100)衬底上外延生长富锗硅锗薄膜。四氟化锗作为锗源, 乙硅烷作为还原性气体。通过设计表面反应, 在低温条件下(350℃)制备了高质量的富锗硅锗薄膜。研究了氢退火对低温硅锗外延薄膜微结构和电学性能的影响。结果发现退火温度高于700℃时, 外延薄膜的表面形貌随着退火温度的升高迅速恶化。当退火温度为650℃时, 获得了最佳的退火效果。在该退火条件下, 外延薄膜的螺旋位错密度从3.7×10⁶ cm^-2下降到4.3×10⁵ cm^-2, 表面粗糙度从1.27 nm下降到1.18 nm, 而外延薄膜的结晶质量也有效提高。霍尔效应测试表明, 经退火处理的样品载流子迁移率明显提高。这些结果表明, 经过氢退火处理后, 反应型热化学气相沉积制备的低温硅锗外延薄膜可以获得与高温下硅锗外延薄膜相比拟的性能。     

热退火对银/铬薄膜界面结构的影响

利用卢瑟福背散射分析和X射线衍射技术，研究了热退火对采用气相沉积方法在AlN基体上制备的Cr／Ag薄膜的界面结构的影响，样品的退火温度范围为200～650℃。实验结果表明：当退火温度达到350℃时，Cr／Ag界面开始互扩散；当退火温度超过550℃，大量铬原子通过银层向试样表面扩散。     

纳米Ta-Al-N薄膜的制备及其扩散阻挡特性的研究

采用直流反应磁控溅射方法在P型（100）Si衬底上制备了Ta-Al—N纳米薄膜与Cu／Ta-Al—N复合膜，并对薄膜样品进行了卤钨灯快速热退火（RTP）。用四探针电阻测试仪（VPP）、AFM、SEM—EDS、Alpha—stepIQ台阶仪和XPd）等分析测试方法对样品的形貌结构与特性进行了分析表征。实验结果表明，本实验条件下制得的Ta-Al—N纳米薄膜表面光滑；随着Al靶溅射功率的增加，Ta-Al—N薄膜中Al含量和方块电阻相应增大，均方根粗糙度降低，而沉积速率变化不大，且Ta-Al—N膜层对Cu扩散的阻挡能力增强。但在过高的温度下退火，导致Cu通过Ta-Al—N的晶界扩散到Ta-Al—N／Si界面并形成Cu3Si，从而引起阻挡层的失效。     

三氧化钨薄膜的光学特性和结构研究

用溶胶-凝胶法和直流反应磁控溅射法制备了表面均匀致密的三氧化钨薄膜,并用双光束紫外可见分光光度计和X衍射分别对薄膜的透光性、结构形态进行了测定;描述了退火温度对薄膜透光性和结构形态的影响,结果表明在高温(＞300℃)退火处理后薄膜的透光率下降,且退火温度越高透光率越低;在350℃以下退火处理后得到薄膜样品为非晶态,在350～400℃范围内退火处理,样品由非晶态向晶态转变.     

磁控溅射ITO薄膜的退火处理

采用直流磁控溅射方法在室温下玻璃基板上制备ITO(Indium tin oxide)薄膜,并在真空中不同温度(100℃~400℃)下退火处理.研究了退火对薄膜表面形貌、电光特性的影响.XRD测试发现薄膜在200℃退火后结晶,优选晶向为(222).随退火温度升高,方块电阻迅速下降,表面更加平整,薄膜在可见光范围平均透过率提高到85%.     

热蒸发制备CdSe薄膜的退火工艺研究

采用真空热蒸发技术在光学玻璃基底上制备了CdSe薄膜,研究了真空下不同退火温度和退火时间对CdSe薄膜晶体结构和表面形貌的影响。XRD结果表明,在400~500℃范围下退火2h、5h的CdSe薄膜晶型不发生改变,结晶性随退火温度升高而增强,其晶粒尺寸从32nm增加至50nm。SEM结果表明,在450℃下退火2h后的CdSe薄膜表面颗粒分布均匀且排列规则、无裂纹。AFM结果表明,在450℃下退火2h后的CdSe薄膜致密性好,表面粗糙度低(5.19nm)。因此采用真空热蒸发制备的CdSe薄膜的热处理条件确定为:退火温度450℃,退火时间2h。     

衬底温度对直流反应磁控溅射TiN电极薄膜显微结构及导电性能的影响

二氧化铪基新型铁电薄膜器件等研究提出了在低衬底温度下制备高导电性和低表面粗糙度纳米超薄TiN电极薄膜的迫切需求。利用直流反应磁控溅射方法在单晶硅基片上制备TiN薄膜,衬底温度范围从室温~350℃,以XPS、XRD、AFM以及XRR等为主要手段对薄膜样品的成分、物相、表面粗糙度以及厚度和密度等进行了表征分析。结果表明在350℃的较低衬底温度下,通过减少溅射沉积时间可获得厚度30nm的高导电性TiN电极薄膜。     

纳米TiO2薄膜的制备与表面形貌研究

研究退火温度对薄膜相结构、表面化学组成及形貌的影响。采用射频磁控溅射法在单晶硅片上淀积TiO2薄膜,通过X射线衍射（XRD）、原子力显微镜（AFM）和X光电子能谱（XPS）对其进行表征。结果表明,室温制备400℃以下退火的TiO2薄膜为无定形结构,400℃以上退火的TiO2薄膜出现锐钛矿相,600℃以上退火的TiO2薄膜开始出现金红石相,退火温度在1000℃以上时样品已经完全转变为金红石相;随着退火温度的升高,晶粒尺寸和表面粗糙度逐渐增大,但是当退火温度为1000℃时反而有所减小,晶粒尺寸和表面粗糙度在退火温度为1000℃时发生的这一突变现象,是由该退火温度下的相变导致。     

退火对铪掺杂类金刚石薄膜结构和力学性能的影响

退火可以改善材料的微结构,增加其韧性和释放其内应力。采用双靶共溅技术制备了铪掺杂类金刚石薄膜(HfDLC)样品,并对样品进行了不同温度的退火处理,研究了薄膜退火前后的形貌、键合结构和硬度和摩擦性能等的变化。结果表明,Hf-DLC薄膜中Hf与C形成纳米晶HfC;在250℃条件下退火,薄膜仍比较稳定;300℃退火后,薄膜结构开始发生变化,表面颗粒增大、变得粗糙;退火温度达到350℃以上,薄膜的结晶性变好,HfC结构增加。薄膜的硬度随着退火温度的增加先略有减小而后增加,薄膜与基体间的结合得到改善,这是由于薄膜的结构随退火温度发生改变所致。     

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.     

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...     

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.     

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.     

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.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

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.