溶胶-凝胶法制备ZrO_2薄膜及其耐腐蚀性与血液相容性研究

采用溶胶-凝胶法在316L不锈钢基底上制备氧化锆(ZrO2)薄膜,薄膜采用分级干燥工艺,经500℃退火制备得到。X射线衍射(XRD)分析了干凝胶粉末的物相结构;扫描电镜(SEM)观察了提拉速度对薄膜表面显微结构的影响;在PBS模拟体液中测试了动电位极化曲线,并对比了试样的耐腐蚀性能;基于接触角测试结果,探讨了薄膜亲/疏水性能,计算了薄膜的表面能及其与血液组分的界面张力。结果表明,500℃退火的ZrO2晶化为四方相结构,以7cm/min提拉速度能制备得到均匀致密的ZrO2纳米薄膜,且具有良好的耐腐蚀性与血液相容性。     

Fe/Si多层膜经快速热退火合成β-FeSi_2薄膜的研究

采用磁控溅射仪在高阻Si(100)衬底上沉积了[Fe(0.5nm)/Si(1.6nm)]120和[Fe(1nm)/Si(3.2nm)]60多层膜,并在Ar气气氛下进行了1000℃,10s的快速热退火。为了比较,也进行了880℃,30min的常规退火。采用X射线衍射仪、原子力显微镜、光谱仪和霍尔效应仪分析了样品的晶体结构、表面形貌、光吸收特性和电学性能。结果表明:Fe/Si多层膜法合成的样品均为β-FeSi2相且在(220)/(202)方向择优生长;经快速热退火合成的β-FeSi2薄膜光学带隙约为0.9 eV。[Fe(1nm)/Si(3.2nm)]60多层膜经快速热退火合成的β-FeSi2薄膜表面粗糙度最小,该薄膜样品为p型导电,载流子浓度为4.1×1017cm-3,迁移率为48cm2/V.s。     

快速退火对直流磁控溅射法制备的AZO薄膜性能的影响

在室温下,采用直流磁控溅射方法制备了不同厚度的氧化锌掺铝薄膜,并对样品进行了快速退火处理,退火温度为600℃,时间为60 s。研究了退火前后薄膜的结构、光电特性的变化情况。退火后,薄膜的最小电阻率为4.2×10-4Ω.cm,其透过率为90.1%。禁带宽度由退火前的3.68 eV变为3.75 eV。     

退火温度对TiO2薄膜结构与光学性能的影响

研究退火温度对薄膜相结构、表面化学组成、形貌及光学性能的影响.采用射频磁控溅射法在单晶硅片和石英玻璃片上负载TiO2薄膜,通过X射线衍射(XRD)、原子力显微镜(AFM)、X光电子能谱(XPS)和紫外可见光谱(UV-vis)对其进行表征.结果表明,常温制备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;高温退火薄膜的组成为TiOx;随着退火温度的升高,薄膜透射率下降,折射率和消光系数有所增加.     

不同靶材制备ZrW_2O_8薄膜的对比研究

分别采用摩尔比n(WO3):n(ZrO2)=2.8:1复合陶瓷靶材、纯ZrW208陶瓷靶材以及WO3和ZrO2双靶,以射频磁控溅射法在石英基片上沉积制备ZrW2O8薄膜.利用x射线衍射仪(XRD)、扫描电子显微镜(SEM)研究了退火温度对采用不同靶材沉积制备薄膜的相组成和表面形貌的影响;用划痕仪、表面粗糙轮廓仪测量薄膜与基片之间的结合力和薄膜厚度.试验结果表明:采用不同靶材磁控溅射制备的薄膜均为非晶态,经过不同温度退火后,不同靶材制备的薄膜的相组成和表面形貌有所不同,但在高温1200℃热处理3 min后均得到立方相ZrW2O8薄膜,其中采用WO3和ZrO2双靶交替磁控溅射制备的立方相ZrW2O8薄膜纯度最高,致密度好,且薄膜与基片之间结合力良好.     

溶胶-凝胶法制备0.1BiFeO3-0.9SrBi2Nb2O9铁电薄膜的结构和光学性质研究

采用硝酸铋[Bi(NO3)3·5H2O]、硝酸锶[Sr(NO3)2]、硝酸铁[Fe(NO3)3·9H2O]和乙醇铌[Nb(OC2H5)5]作为起始原料,乙二醇甲醚[C3H8O2]作为溶剂配制掺Fe的SrBi2Nb2O9前驱体溶液,利用溶胶-凝胶法在石英衬底上制备出0.1BiFeO3-0.9SrBi2Nb2O9铁电薄膜.研究了该薄膜的表面形貌、组分、晶体结构和光学性质.结果表明,经400℃退火后薄膜为非晶结构,而在空气中经600℃退火1h后,沉积的薄膜晶化成钙钛矿结构.制备的薄膜表面平整,颗粒分布均匀,表现出良好的光透过性,该薄膜的光学能隙大约为2.5eV.     

退火对Al-Sb多层薄膜的影响

采用直流磁控溅射法制备Al和Sb交替层,在真空环境下进行高温退火后得到了AlSb多晶薄膜.通过X射线衍射(XRD)、霍尔效应、暗电导率温度关系以及透反射光谱研究了薄膜的结构、电学和光学性质.结果表明,退火后形成的AlSb多晶薄膜呈立方相,沿(111)择优取向,且导电类型是P型,载流子浓度为1019cm-3,吸收系数在可见光波段大于104cm-1.样品在580℃退火后,间接跃迁光能隙为1.64eV,且升温电导激活能为0.01eV和0.11eV.此方法制备的AlSb多晶薄膜应用于TCO/CdS/AlSb/ZnTe:Cu/Au结构的太阳能电池中,得到了107mV的开路电压.     

退火温度对BiFeO_3薄膜结构和表面特性的影响

为了确定BiFeO_3薄膜最佳的退火温度,利用溶胶凝胶法在Si衬底上制备了BiFeO_3薄膜,通过XRD、SEM和Raman等测试手段研究了不同退火温度(0,600,700,800℃)对BiFeO_3样品的薄膜结构和表面形貌的影响。结果表明,经过退火后的BiFeO_3薄膜呈现正交相与六方相共存的结构,随着退火温度升高,样品开始结晶,但过高的退火温度将导致样品出现杂相。同时,适当的退火温度可减小BiFeO_3薄膜表面的孔洞和空隙,提高材料的平整度,随着温度进一步提高,薄膜表面出现气泡,材料的平整度变差。另外,经过退火处理的样品具有较强的拉曼振动峰,但温度的升高将引起Raman特征峰发生红移。上述结果证实了利用溶胶-凝胶法制备的BiFeO_3薄膜的最佳退火温度为600℃,该实验结果为改善BiFeO_3的物相结构和表面特性提供了一种新的技术思路与途径。     

退火温度对Ge/SiO2多层膜的结构和光学性能的影响

采用磁控溅射技术在石英衬底上制备出(Ge/SiO2)15多层膜,并在不同温度下对其进行退火处理。XRD和Raman结果表明:溅射态的薄膜为非晶态,当退火温度为500℃时开始出现明显的结晶衍射峰,随后晶化率明显增大,当600℃后,薄膜的晶化率几乎不变。FESEM和小角度X射线衍射结果表明:溅射态薄膜的层与层之间存在明显的界面,具有良好的周期性,升高退火温度,晶粒尺寸增大,但仍保持周期性结构。薄膜的紫外-可见光吸收光谱表明:随着退火温度的升高,吸收边发生红移,光学带隙从溅射态的1.86eV减小到600℃时的1.59eV。     

不同退火方式对0.7BiFeO3-0.3PbTiO3薄膜的铁电性能及漏电流的影响

利用溶胶凝胶法在LaNiO3/SiO2/Si衬底上制备了0.7BiFeO3-0.3PbTiO3(BFPT7030)薄膜,研究了快速退火及常规退火两种不同的后续退火处理方式对薄膜铁电性能及漏电流性能的影响.XRD测试表明,经快速退火处理的BFPT7030薄膜结晶完好,呈现出单一的钙钛矿相.SEM测试结果显示,经快速退火处理的BFPT7030薄膜结晶充分,但经常规退火处理的BFPT7030薄膜表面致密性较好,且在升温速率为2℃/min时薄膜的晶粒更细小.经快速退火处理的BFPT7030薄膜的铁电性能较为优异,在升温速率为20℃/s时,其剩余极化Pr为22μC/cm2,矫顽场Ec为70 kV/cm,并具有较小的漏电流.XPS测试结果表明,经常规退火处理的BFPT7030薄膜其铁离子的价态波动较小.     

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.