退火对低温射频磁控溅射Ba铁氧体薄膜结构及磁特性的影响

用ＲＦ磁控溅射法，在纯Ａｒ气中，硅基片不加热的情况下，制备了Ｂａ铁氧化薄膜，研究了退火温度对薄膜Ｃ轴垂直取向、结构及磁特性的影响，结果表明薄膜在７００℃氧气中退火可获得良好Ｃ轴垂直膜同的择优取向，该薄膜的饱和磁化强度和矫顽力分别为Ｍｓ＝２９６ｅｍｕ／ｃｍ＾３，Ｈｃ＝３０８７６１Ａ／ｍ。退火温度过低或过高，都不利于形成Ｃ轴垂直膜面的择优取向。     

退火对低温射频磁控溅射Ba铁氧体薄膜结构及磁特性的影响

用RF磁控溅射法，在纯Ar气中，硅基片不加热的情况下，制备了Ba铁氧体薄膜，研究了退火温度对薄膜c轴垂直取向、结构及磁特性的影响，结果表明薄膜在700℃氧气中退火可获得良好c轴垂直膜面的择优取向，该薄膜的饱和磁化强度和矫顽力分别为Ms=296emu／cm3，Hc=308761A／m。退火温度过低或过高，都不利于形成c轴垂直膜面的择优取向。     

钡铁氧体薄膜的c轴取向生长

首次使用非晶Ｂａ－Ｆｅ－Ｏ衬底层来控制钡铁氧体（ＢａＭ）薄的取向芝种非晶层决定了六角Ｍ相的结晶并改善了其晶化度。应用这各非晶衬底层,制备了ｃ轴垂直于膜表平面的ＢａＭ薄膜,其（００８）峰的摇摆曲线的半高宽△θ５０仅为２．５°。     

钡铁氧体垂直磁化膜磁各向异性研究

钡铁氧体垂直磁化膜可用作高密度磁记录介质。本文研究用低温ＲＦ磁控溅射法制备非晶薄膜，经晶化处理所得到的垂直磁化膜的饱和磁化强度Ｍｓ、矫顽力Ｈｃ及垂直磁各向异性常数Ｋｕｌ、Ｋｕ２与退火温度Ｔ的关系，并对所呈现出的变化规律作了简单解释。介绍了依据转矩曲线的形状来判断薄膜垂直性优劣的方法，从转矩曲线出发，探讨了影响薄膜磁各向异性的因素。     

透明BaO·B2O3玻璃陶瓷的表面形貌、结构特征及光学性能

以ＢａＣＯ３、Ｈ３ＢＯ３为原料，经高温熔融及控制热处理，获得了ＢａＯ·Ｂ２Ｏ３透明玻璃陶瓷。利用ＸＲＤ、ＳＥＭ等手段研究了该材料的结构特征及表面形貌。结构表明，在玻璃表面得到了含有单一β－ＢａＢ２Ｏ４（ＢＢＯ）晶相结构的析晶薄膜层，薄膜表面均匀，单膜厚度约２μｍ，晶粒平均尺寸约０．２μｍ，且微晶粒沿α轴方向优先生长；析晶优先从玻璃表面开始向内部进行，形成晶化层－玻璃－晶化层三元“夹心”结构。该玻璃     

磁控溅射法制备NiZnCo铁氧体磁性薄膜的工艺研究

采用磁控溅射在硅晶基体上制备NiZnCo铁氧体磁性薄膜,研究了溅射功率对溅射(沉积)速率和微观形貌的影响规律:随着溅射功率由80W增大到150W,薄膜的沉积速率增大;薄膜却由整齐均匀分布的小颗粒状向片状结构变化,分布也不均匀,晶粒明显长大.由此确定最佳溅射功率为120 W,薄膜的微观形貌最理想,溅射(沉积)速率也很快.     

磁控溅射法制备纳米晶钛薄膜工艺研究

利用直流磁控溅射法在硅基底上沉积出纳米晶钛薄膜,研究了背底真空度、溅射功率和基底温度对纳米晶钛薄膜结构的影响。实验证明,当背底真空度高于8.8×10-5 Pa时,可制备出致密的纳米晶钛薄膜,当背底真空度低于2.0×10-4 Pa时,钛薄膜被氧化成一氧化钛薄膜;随着溅射功率的增大,纳米晶钛膜的晶粒尺寸呈线性增大,同时钛薄膜的取向也发生改变,表现出明显的(002)织构;随着温度的升高,钛薄膜织构取向发生改变,当温度为500℃时,钛薄膜被氧化为一氧化钛薄膜。制成平整钛薄膜的工艺条件为:背底真空度8.8×10-5 Pa,溅射功率200 W,基底温度室温。     

CoMnNiO非晶薄膜热致相变

射频溅射的ＣｏＭｎＮｉＯ非晶薄膜在一定温度下热处理产生晶化，经历一个非晶－微晶－多晶的相变过程。ＸＲＤ和ＴＥＭ分析表明ＣｏＭｎＮｉＯ非晶薄膜在３００℃开始晶化，６００℃晶化完全，生成尖晶石多晶。其相变机制是原子扩散和链状组织的规则排列以及有序集团的凝聚合并。     

溅射法制备Mn-Zn铁氧体薄膜的磁性与微结构

以交替真空溅射的方法使用成分分别为MnFe2O4与ZnFe2O4的双靶制备了成分变化的系列Mn1-xZnxFe2O4铁氧体薄膜,衬底为Si(100)。薄膜的成分通过控制不同靶的溅射时间来进行调整。沉积态的薄膜呈非晶结构,在真空炉中以适当的温度对薄膜进行退火之后能够得到多晶Mn-Zn铁氧体薄膜。组成成分为Mn0.5Zn0.5Fe2O4的薄膜呈现了相对最高的饱和磁化强度。同时还研究了制备条件对薄膜结构与磁性的影响,如溅射氧分压,退火真空度,退火温度及薄膜厚度等等。制备的薄膜相对于块状材料具有较高的矫顽力,进而讨论了应力对薄膜矫顽力的影响。     

用于主读存储器的无定形半导体薄膜的射频溅射工艺研究

射频溅射技术优点很多，可适用于无定形半导体的成膜。但对析晶温度较低的无定形材料，要得到性能良好的无定形薄膜、靶材和衬底需要良好的冷却。本文采用特殊设计的氟里昂机组冷却酒精，然后将低温酒精冷却靶材和衬底，这样可得到满意的效果。控制Ｔｅ８１ＧＴｅ１５Ｓ２Ｓｂ２的无定形半导体的溅射速率和薄膜的厚度，能制得性能优良的主读存储器件。     

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.     

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.     

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.