单壁碳纳米管的纯化研究

本试验通过化学法和物理法相结合的方法,将液相氧化、超声、过滤和离心等手段相结合对单壁碳纳米管进行纯化,通过扫描电子显微镜观察和拉曼光谱验证了纯化结果,研究结果证明该方法可以明显的减少单壁碳纳米管中的杂质,使单壁碳纳米管的纯度明显提高。     

空气氧化法提纯碳纳米管的研究

以乙炔为原料气，采用铁-镍复合催化剂，在700℃下，由化学气相沉积法(CVD)制得了直径为10nm～30nm的多壁碳纳米管(MWNT)。然后通过空气氧化法对所获碳纳米管进行提纯，去除了碳纳米管中的无定形炭、炭纳米颗粒及炭纤维等非晶碳成分，提高了碳纳米管的纯度；并研究了提纯温度和时间的关系。结果表明：碳纳米管在空气中440℃加热3h后，烧损率趋于平稳，基本上稳定在2％左右。使用透射电镜(TEM)考察提纯前后碳纳米管的形貌，发现碳纳米管在空气中440℃加热3h后，非晶碳成分基本去除，纯度得到提高。     

单壁碳纳米管-石墨烯杂化材料的自组装及其电学性能（英文）

以Si为基底,采用气相沉积法制备出石墨烯(G/Si)薄膜。将含1%APTES的苯溶液与G/Si密封,在115℃下加热2 h,G薄膜上自组装单层APTES膜(SAM-G/Si)。将SAM-G/Si浸渍于酸处理后的单壁碳纳米管氯仿液中,45℃干燥即得到单壁碳纳米管-石墨烯杂化材料(SWCNT-G/Si)。结果表明,具有p-型电学性能的G/Si经表面改性后呈现出n-型性能,电容性能得到提高。     

利用振动研究单壁碳纳米管力学性能

单壁碳纳米管的力学性能是碳纳米管增强复合材料和碳纳米管器械的基本问题之一。文中根据分子结构力学方法建立单壁碳纳米管的有限元模型,通过振动频率计算单壁碳纳米管的弹性模量和剪切模量。详细讨论了用不同阶数弯曲振动固有频率和扭转振动固有频率求得的弹性模量和剪切模量结果的准确性,并分析了单壁碳纳米管的直径对弹性模量及剪切模量的影响。     

热处理对单壁碳纳米管场发射的影响

将单壁碳纳米管组装于W针尖，对它进行热处理，得到单壁碳纳米管在不同温度去气时的残气质谱图和热处理后的场发射特性曲线。通过对不同温度去气后的I－U特性曲线的Fowler-Nordheim直线斜率的变化，结合残气质谱图的分析，研究热处理对单壁碳纳米管场发射特性的影响，并对其机理进行了初步讨论。     

单壁碳纳米管的制备及生长特性研究

采用Fe／MgO作为催化剂，催化裂解CH4制备了较纯的单壁碳纳米管，用TEM和Baman对碳纳米管进行了表征，对不同生长温度下制备的碳纳米管Baman径向呼吸振动峰(RBM)进行了分析，研究了生长温度对单壁碳纳米管生长特性和结构特性的影响。     

Ho/Ni作为催化剂合成单壁碳纳米管

利用直流电弧等离子体方法，以Ho／Ni作为催化剂合成了单壁碳纳米管，借助扫描电子显微镜、拉曼光谱和热重分析方法对所合成的单壁碳纳米管的形貌、结构以及含量进行了表征。电镜观察以及热重分析表明，收集到的大量网状物中单壁碳纳米管含量较高；不同激发波长拉曼测量表明碳纳米管直径分布比较集中，在1．35nm～1．69nm范围，且直径为1．5nm的碳纳米管占多数；与Ce／Ni等作为催化剂合成的单壁碳纳米管的直径分布不同。研究结果表明，Ho／Ni对于合成单壁碳纳米管具有很好的催化效果且影响管径分布，元素Ho对单壁碳纳米管的形成起到了重要的作用。     

不同结构的碳纳米管对苯胺吸附性能的研究

以CCVD法制备的碳纳米管为原料,使用加热和硝酸回流的方法进行纯化处理,比较了未处理和处理后的碳纳米管对苯胺的吸附.结果表明经过纯化处理后碳纳米管的比表面积和孔容有了明显改变;使用硝酸回流处理的碳纳米管还会在其表面引入-OH、＞C=O、-COOH等官能团.纯化过的碳纳米管较未纯化过的碳纳米管对苯胺的吸附量大大提高.     

碳纳米管应用的新拓展--红外探测与超导

具体阐述了碳纳米管用于红外探测的可行性以及在单壁碳管内实现超导态的实验方法，对用碳纳米管阵列制作红外探头的理论基础，典型特性和技术状况均进行了讨论，此外，具体分析了用“接近诱导法！实现碳纳米管的超导电态的实验方法，即将单壁碳纳米管束或单个碳纳米管嵌放在两个超导电极之间，在一定的条件下，有可能在碳管内诱导出超导电流，已有的实验显示碳纳米管内超导电流的临界值较大，并表现出特殊的对温度和磁场的依赖性。     

单壁碳纳米管无纺膜的抗凝血性能研究及其对血液系统中植入性假体的意义

以血液接触环境下的应用为目标，研究了单壁碳纳米管无纺膜的抗凝血性能。通过扫描电镜(SEM)观察和表面元素分析，研究了与凝血过程密切相关的纤维蛋白原、白蛋白以及新鲜血浆在单壁碳纳米管无纺膜表面的吸附行为，并利用SEM和荧光标记流式细胞分析技术(FCM)，从血小板活化形态和血小板膜糖蛋白的构型变化两个方面分析了单壁碳纳米管无纺膜对血小板的作用。实验结果显示，单壁碳纳米管无纺膜对血液中的纤维蛋白分子原具有明显的倾向性吸附，但是并没有像已有的大部分生物材料一样引起明显的后续血小板粘附和活化，材料与血浆接触后，表面上没有观察到可辨识的血小板粘附与活化，富血小板血浆(PRP)中活化血小板在5％左右，表明该材料具有独特的抑制血小板粘附、活化和聚集的抗凝血性能。这种优异的抗凝血性能在血液接触环境中的人工器官、组织替代物、以及可植入器件等方面具有巨大的潜在应用价值。     

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.     

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.     

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.