水热法在碳纤维表面生长ZnO纳米线及性能研究

采用水热法在碳纤维表面生长ZnO纳米线,通过扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和SmileView软件对ZnO纳米线进行分析。XPS结果确认碳纤维表面纳米线为ZnO纳米线,SEM图片说明T700碳纤维表面ZnO纳米线取向度高于T300碳纤维表面ZnO纳米线,关于生长时间的分析表明最优值为4h。此外,通过附着生长在碳纤维表面制备了改性的ZnO纳米线,XPS测试结果表明ZnO纳米线表面涂层为CoO。     

利用静电纺丝技术制备ZnO纳米线

用电纺得到的ZnO／SiO2复合纤维膜,浸在溶胶-凝胶法制备的ZnO溶胶中2h,使其充当控制ZnO纳米线（棒）生长的先驱物种子,再采用溶液生长法制备ZnO纳米线。结果表明先驱ZnO薄膜可以控制生长的ZnO纳米线。     

紫光激发提高Ag修饰的ZnO纳米线的气敏特性

为了提高ZnO纳米线的酒敏特性,利用紫光激发经浸渍法获得Ag修饰的ZnO纳米线.利用扫描电子显微镜（SEM）,X射线衍射仪（XRD）对修饰后的ZnO纳米线进行了晶体结构和形貌的表征.结果表明其晶体结构中既有六方纤锌矿结构的ZnO,又有面心立方的Ag.三维网络结构的ZnO纳米线的表面被一层致密的具有高孔隙率的Ag颗粒覆盖,使得ZnO纳米线具有更高的比表面积.纯ZnO纳米线和Ag修饰的ZnO纳米线都用作气敏基料,根据它们在酒精蒸气中紫光照射和无紫光照射条件下电阻的变化来测定它们的气敏特性.结果显示紫光照射下经质量分数为6%AgNO3修饰的ZnO纳米线对酒精蒸气的最大灵敏度由75.8提高到175.77.此过程中光催化氧化-还原反应起到了重要作用.     

Ag纳米粒子修饰ZnO纳米线特性研究

利用水溶液法制备ZnO纳米线,使用真空热蒸发方法用Ag对ZnO纳米线进行表面修饰。用场发射扫描电子显微镜(FESEM)、X射线衍射(XRD)仪、吸收谱仪分析它们的表面形貌、物相结构及光学性质,同时分析了其场发射性能。结果表明,随着Ag修饰量的增加,ZnO纳米线表面上的Ag纳米粒子分布会由稀疏逐步到致密,最后Ag的纳米粒子几乎连在一起。测量吸收谱线发现修饰后的ZnO纳米线的吸收能力变强,但存在一个临界值,当修饰量超过临界值后,ZnO纳米线的光吸收能力会减弱。对修饰后ZnO纳米线的场发射性能进行初步测试,结果表明适当量的Ag修饰可以有效降低ZnO纳米线的场发射开启电压。     

Ag掺杂ZnO纳米线酒敏性能的研究

利用浸渍法将ZnO纳米线浸渍于AgNO3溶液中制备了Ag 掺杂的ZnO纳米线.借助X射线衍射仪(XRD)和场发射扫描电子显微镜(FESEM)对纳米线的晶体结构和形貌进行了表征.结果表明纳米线既含面心立方结构的Ag又含有六方纤锌矿结构的ZnO.三维网络结构的ZnO纳米线被一层致密的Ag颗粒包裹并在其表面形成了大量的具有高比表面剂的孔洞结构.将纯的和Ag掺杂的ZnO 纳米线都作为酒敏传感材料,在酒精浓度为0.001%,工作温度为150～400℃的范围内测试了它们的气敏特性,结果显示,Ag掺杂的ZnO纳米线的酒精灵敏度比纯ZnO纳米线提高了14.在工作温度为350℃的条件下测试了它们的响应-恢复时间.气敏元件的酒敏特性主要归结于表面吸附效应.     

ZnO纳米线阵列修饰对材料表面浸润性调控

采用溶胶-凝胶法制备了ZnO薄膜,利用溶剂热沉积法获得大面积均匀ZnO纳米线阵列。通过对水在ZnO材料表面的浸润性研究,发现薄膜材料表面的粗糙度对ZnO膜亲水性有增强作用,而周期性ZnO阵列微结构表面可以实现其疏水性质增强效果。同时从理论上分析了这两种现象的物理机制,讨论了空气填隙对ZnO纳米线阵列表面的浸润性质的敏感性。制备出ZnO纳米线阵列的表观接触角约为103°,具有较强的疏水性质,可为进一步的ZnO光流控研究提供实验基础。     

不同温度和时间对SMAT黄铜基底生长ZnO纳米结构与形貌的影响

利用热氧化法,在不同氧化温度、保温时间条件下,在经过SMAT处理的Cu-Zn合金基底上生长出ZnO纳米线。采用X射线衍射、扫描电子显微镜、高分辨透射电子显微镜对样品结构、形貌进行了分析表征。结果表明:表面生长的纳米线为六方结构ZnO;氧化温度、保温时间对ZnO纳米线形貌有较大影响。总结了纳米线的生长机理。     

AZO晶种层对ZnO纳米线生长及紫外光电导性能的影响

采用溶液化学法实现了在Zn(NO3)2/C6H12N4混合溶液中ZnO纳米线在AZO薄膜修饰过衬底上生长。AZO薄膜由射频磁控溅射法制备,通过溅射时间和基底温度的变化改变薄膜形态,重点研究了不同薄膜形态对ZnO纳米线形貌和结构的影响,最终在溅射2h、基底温度250℃晶种上得到垂直于衬底、高度平行取向的ZnO纳米线阵列。在此基础上研究了不同形貌ZnO纳米线阵列的紫外光电导性能差异。结果表明,垂直生长的纳米线较倒伏纳米线紫外响应迅速,分析认为是紫外光照下曝光面积不同造成的。     

ZnO纳米线的可控生长及其光学特性

采用简单水热法制备得到ZnO纳米线,通过控制反应条件调控ZnO纳米线的形貌,得到不同形态的多维ZnO纳米线。利用扫描电镜(SEM)、X射线衍射(XRD)、光致发射光谱(PL)对样品的微观形貌、晶相结构、光学性能进行表征,结果表明:样品的晶型完整,光致发射光谱图显示在384nm左右出现了紫外区发射峰,而且玉米棒状ZnO纳米线不仅出现了强烈的紫外发射峰,在可见光区域也出现了发射峰。     

ZnO纳米线的制备及场发射特性的研究进展

从ZnO纳米线的生长机制出发,重点讨论了催化剂在制备过程中的作用,比较了采用VLS和VS不同机制生长ZnO纳米线的优缺点,并结合二者特点发现采用金属自催化将是制备高质量ZnO纳米线阵列的一种有效方法.分析了几种有利于提高其场发射性能的后处理方法,经过适当的后处理ZnO纳米线晶体的结构将更加完善,场发射开启场、阈值场将进一步降低,电流密度和场增强因子也将随之大大提高.     

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.……     

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.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.