溶胶——凝胶TiO2制备透明激光全息薄膜的研究

溶胶-凝胶是制备新材料的一种很有用的方法。采用溶胶-凝胶方法在普通透明塑料基底上制备具有纳米结构的TiO2薄膜，用激光微雕模版将全息图案复合在该薄膜上制成透明激光全息薄膜。选择酸性催化TiO2溶胶，在烘道里以100℃左右的温度完成溶胶-凝胶，并注意控制其它相关的条件使至获得厚度的1-2um，折射率n=1.8的高反射低吸收的介质薄膜。对制得的溶胶-凝膜介质薄膜在模压机上施以2-4kg/cm^2的压力和100℃的温度，复制出由激光刻制的光删条纹。当有较大角度的入射光进入薄膜时，在不影响透明的同时整个薄膜展现完整的全息图象。     

溶胶-凝胶TiO2薄膜的激光全息衍射特性

将全息图象以激光刻制的光栅条纹通过膜压的方法复制到溶胶-凝胶TiO2薄膜,在很大的视角范围内得到完整的再现.本文介绍了具有高折射率的溶胶-凝胶材料的选择和薄膜的制备方法;讨论了与再现全息图象有关的薄膜的光学特性.溶胶-凝胶TiO2薄膜的折射率n=1.8～1.9,薄膜厚度1～2 μm,正弦波状光栅,条纹深度大于100 nm对于增加全息图象的衍射效率是有利的.衍射效果随视角增大而加强,视角60°以上最好.     

具有纳米结构的TiO2透明激光全息防伪薄膜

在透明塑料基底上制备具有纳米结构的高折射率TiO2薄膜,代替原来的镀铝薄膜制成的防伪制品大大增加了技术含量,使仿冒变得困难.该薄膜是透明的,同时又清晰显现激光全息图像,具有很强的装饰效果,因此开拓了十分广阔的应用领域.采用溶胶-凝胶(Sol-Gel)方法制备TiO2薄膜.通过对材料的组分、配比以及薄膜的颗粒、骨架、孔洞等微结构进行调控,形成网状多孔纳米结构来满足各方面的特性需要,包括适应制作透明激光全息薄膜的光学特性.该薄膜材料的孔洞率大于90%,孔径尺寸仅几十纳米,这种结构能够较好再现激光图像.体现全息图像的光栅条纹是用激光微雕的方法预先制好,并复制到金属镍板上,在专用的模压机上将光栅条纹复制到TiO2薄膜上,达到完整再现全息图像.通过研究和实践,我们制作的TiO2薄膜厚度(1～2)μm,透射率为90%以上,折射率n=1.8～1.9;光栅条纹正弦波状,深度为100 nm.这样的透明激光全息薄膜衍射效率达到1.9,在保持薄膜良好透明性的同时能明显地显现出全息图像.衍射效果随视角增大而加强,视角60°以上最好.     

TiO2纳米颗粒的制备及光催化降解甲醛的研究

本工作系采用溶胶-凝胶法合成TiO2颗粒的平均粒径为20mm，电子衍射环图结果表明TiO2颗粒晶体结构为锐钛矿型，在光催化反应系统中对上述TiO2颗粒制备的薄膜进行了甲醛的光催化降解实验，考察了TiO2颗粒制备的薄膜的层数，溶胶体系pH值，活化温度及活化时间等条件对TiO2薄膜光催化降解甲醛性能的影响。实验结果表明，溶胶-凝胶法的制备工艺条件对TiO2薄膜的光催化不知性有着较大的影响，活化的温度和活化的时间影响最大，其次就是溶胶体系的pH值，当pH=2，活化温度为500℃，活化时间5h，制成的TiO2薄膜光催化降解甲醛的降解率可以达到60%以上。     

具有一定取向的TiO2薄膜的研究与制备

用浸渍法将P25粉末涂敷于溶胶-凝胶法制备的TiO2预制膜上,进行一系列的热处理,制备TiO2薄膜样品.用X射线衍射法对样品进行晶体结构分析,发现用这种方法可以得到具有一定取向的TiO2薄膜.其结晶程度和取向度与浸渍时间和热处理时间相关,在浸渍时间为10h、热处理温度为500℃时,得到沿(101)面方向取向生长的TiO2薄膜.     

透明全息防伪薄膜光学性质研究

一种透明全息防伪薄膜,在透明的同时反射全息图像.用全息摄影、激光雕刻和电铸手段,以光栅条纹的形式记录和制备金属模版.热压具有蚋米结构的TiO2信息层,再现全息图像.用溶胶-凝胶方法制备信息层,选择合适的前驱体、催化剂、热处理条件使折射率≥1.8.据光学匹配原理设计膜系,信息层/基底层厚度分别为≥0.3 μm和≥10μm.正弦波状光栅,深度0.1 μm.在视角≥60再现的全息图像最清晰.     

溶胶-凝胶法制备TiO_2薄膜及其光学性能的研究

采用溶胶-凝胶法在K9玻璃上制备了均匀、透明、裂纹较少的纳米TiO2薄膜,以无水乙醇用量、涂层数、煅烧温度为影响因素,设计L9(3)4正交试验,以薄膜的透明度、微观致密程度作为评价标准,讨论了无水乙醇用量、涂层数和煅烧温度对制备TiO2薄膜光学性能的影响。用反射式椭圆偏振光谱仪测试最佳制备工艺下制得的TiO2薄膜的椭偏参数,并用Cauchy模型对椭偏参数进行数据拟合。结果表明,薄膜最优制备工艺参数为无水乙醇用量30 m L、涂层数为2层、煅烧温度为550℃;Cauchy模型能较好的描述溶胶-凝胶薄膜在300~700 nm波段的光学性能;薄膜的折射率和消光系数都有随波长增大而减小的趋势且制备的薄膜具有随着膜层数的增加,折射率增加,而最大峰值透光率、孔隙率减小的规律。     

TiO2纳米颗粒/纳米线复合光阳极的染料敏化太阳能电池

首先采用水热合成技术制备TiO2纳米线粉末,然后采用溶胶-凝胶技术制备钛酸丁酯溶胶,向溶胶中加入适量的TiO2纳米线制备凝胶浆体,采用浸渍提拉法在透明导电玻璃上制备TiO2纳米颗粒/TiO2纳米线复合薄膜的光阳极.通过XRD、SEM,电池的I-V特性和电化学阻抗谱测试,研究TiO2纳米线的添加量对光阳极的结构、形貌和电...     

塑料基TiO2电致变色薄膜制备及性能研究

采用溶胶-凝胶法分别在镀有ITO透明电极的玻璃和塑料基体上制备了TiO2电致变色薄膜,对比研究了不同基体上溶胶的成膜性及薄膜的电致变色性能.结果表明:在相对湿度低于15%的环境中,采用0.4mol/L的溶胶可以通过多次提拉制得表面光洁的较厚透明TiO2薄膜;随热处理温度的升高,薄膜的电色可逆性变好,循环寿命变大,但离子储存能力下降;塑料基TiO2薄膜与相同条件下制备的玻璃基薄膜具有相似的性能,呈现出较弱的阴极电致变色效应和较强的Li 储存能力,有望用作柔性电致变色器件的对电极.     

直接氮化法制备纳米晶TiN薄膜

首先采用溶胶-凝胶法在Al2O3基体上制备了TiO2纳米晶薄膜，然后在管式气氛炉中，用氨气作为还原剂，直接氮化制备TiO2纳米晶薄膜；从而成功地的α-Al2O3陶瓷基片上制备了纳米晶TiN薄膜。利用XRD、XPS、FE-SEM等分析技术，研究了制备的纳米晶TiN薄膜的相组成及形貌。结果表明最佳工艺条件为：氮化温度为700℃，氮化时间为1h。     

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...     

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.     

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.     

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.……     

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.     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.     

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.     

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.     

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