核壳结构TiO2/Ag反蛋白石的制备与形貌观察

用化学还原法制备了银包覆聚苯乙烯(PS)微球结构,通过垂直沉积法排列出具有密堆积结构的PS-Ag蛋白石模板,然后采用溶胶-凝胶法渗透TiO2,最后焙 烧 处 理 除 去PS,制 备 出 了 规 整 的 核 壳 结 构TiO2/Ag反蛋白石。采用扫描电镜、透射电镜和X射线衍射对该样品进行了分析。结果表明,PS球表面包覆的为纳米尺度的金属银;所制备的PS/Ag核壳微球蛋白石经过480℃、12h焙烧处理后获得的核壳TiO2/Ag反蛋白石结构的单胞参数可以通过调节包覆银层的厚度来调变,即改变AgNO3与PS球的质量比获得具有不同银包覆层厚度、不同单胞参数的三维蛋白石和反蛋白石结构。     

纳米尺度PS/Ag核壳结构复合球的制备与表征

采用分步法制备了聚苯乙烯/银(PS/Ag)核壳结构复合纳米球。首先采用无皂乳液聚合法并利用丙烯酸(AA)的羧基对制备的PS球进行改性,使其表面带负电荷;然后通过静电吸附作用在改性PS球的表面沉积[Ag(NH3)2]+,水浴(80℃)环境中利用十二烷基磺酸钠(SDS)作为还原剂将PS球表面的[Ag(NH3)2]+还原,制备出PS/Ag核壳结构复合球。通过动态激光粒度分析仪和透射电子显微镜对PS/Ag核壳纳米球的粒度分布、形貌和结构进行了表征,研究了AA的用量对复合球粒径及包覆的Ag壳厚度的影响。结果表明,随着AA用量的增大,所包覆的银层更加致密,厚度增大,当AA用量为15%时可得到Ag完全包覆的PS/Ag复合纳米球。     

无皂乳液聚合法制备PS/TiO2核-壳复合微球

采用无皂乳液聚合法制备聚苯乙烯(PS)微球,将所制备的PS微球经磺化吸水后,利用钛酸丁酯作前驱体在乙醇中反应,使TiO2包覆在磺化苯乙烯微球表面,得到有机-无机PS/TiO2复合微球。在所得的杂化微球表面接枝上可聚官能团,利用无皂乳液聚合将聚甲基丙烯酸甲酯聚合到微球表面,得到核-壳-壳杂化微球。用FT-IR、SEM和TGA等方法对所制得的复合微球进行表征。结果表明PS、PS/TiO2及PS/TiO2/PMMA微球表面光滑,球形度好,单分散性良好;通过改变TBOT的加入量可以控制TiO2对PS微球的包覆厚度。     

聚苯乙烯/银核壳结构纳米微球的制备与表征

采用两步法的简单路线制备出银纳米粒子包覆的聚苯乙烯(PS)微球,首先通过乳液聚合法合成出聚苯乙烯微球;然后对苯乙烯进行敏化和活化,搅拌下加入银的还原液,从而制备出Ag-PS核壳结构的纳米微球.同时借助于TEM、UV-vis、 FE-SEM进行表征,分析其微观结构.结果表明,所得的聚苯乙烯微球粒径约为40nm;聚苯乙烯/银核壳结构纳米微球粒径为45～350nm,银层厚度可随意调控.     

分散聚合法制备SiO2/PAM核壳复合微球

采用分散聚合法制备出以SiO2为核、PAM为壳的核壳复合微球。根据Stber法制备了单分散SiO2微球,粒径随着TEOS、氨水浓度的增加而增大。采用硅烷偶联剂对SiO2微球进行表面处理,TEM显示处理后的微球继续保持单分散性,粒径有所增加。以SiO2微球或处理后的SiO2微球为核,采用分散聚合法在其上包覆AM,借助TEM、IR对其进行表征;研究发现,以处理后的Si O2微球为核能得到核壳结构,这种SiO2/PAM核壳微球的粒径大约为163 nm,包覆层30 nm左右。     

α-N（OH）2/SiO2核壳以及α-Ni（OH）2空心微球的制备及表征

采用以正硅酸乙酯（TEOS）水解为基础的硅溶胶种子生长法制备了粒径约为270nm的近单分散二氧化硅球型颗粒.采用一种新的溶液生长法,以氢氟酸作为溶液中镍离子配位剂,加入氨水调节溶液pH值的同时作为镍离子补充配位剂,60℃水浴条件下在已制得SiO2微球表面均匀包覆α-Ni（OH）2得到Ni（OH）2/SiO2核壳结构,Ni（OH）2壳层厚度约为35nm.结合多步包覆法提高Ni（OH）2壳层厚度,三次包覆后壳层厚度达到约100nm,四次包覆后约为140nm.采用20wt%的强碱NaOH溶液对三次包覆后的Ni（OH）2/SiO2核壳结构进行处理,得到了壳层厚度约为95nm的α-Ni（OH）2空心微球.空心微球具有较大的比表面积为141.06m2/g.     

α-Ni(OH)2/SiO2核壳以及α-Ni(OH)2空心微球的制备及表征

采用以正硅酸乙酯(TEOS)水解为基础的硅溶胶种子生长法制备了粒径约为270nm的近单分散二氧化硅球型颗粒.采用一种新的溶液生长法,以氢氟酸作为溶液中镍离子配位剂,加入氨水调节溶液pH值的同时作为镍离子补充配位剂,60℃水浴条件下在已制得SiO2微球表面均匀包覆α-Ni(OH)₂得到Ni(OH)₂/SiO₂核壳结构,Ni(OH)₂壳层厚度约为35nm.结合多步包覆法提高Ni(OH)₂壳层厚度,三次包覆后壳层厚度达到约100nm,四次包覆后约为140nm.采用20wt％的强碱NaOH溶液对三次包覆后的Ni(OH)₂/SiO₂核壳结构进行处理,得到了壳层厚度约为95nm的α-Ni(OH)₂空心微球.空心微球具有较大的比表面积为141.06m²/g.     

以油菜花粉为模板水热法制备TiO2中空微球

以油菜花粉为模板,先用超声使花粉分散在无水乙醇中,再通过水热法制备了TiO2前驱体/花粉壳-核微球;550℃焙烧脱除花粉核后得到了TiO2中空微球.采用SEM,TG,XRD,FTIR和N2吸附对TiO2前驱体/花粉壳-核微球及TiO2中空微球进行了表征.结果表明:在TiO2前驱体/花粉壳-核微球的制备过程中,超声波诱导能使TiO2前驱体较均匀的负载在花粉表面,适宜的钛酸丁酯用量为6.6 g/g花粉,适宜的水热处理温度为105℃.在此条件下得到的TiO2前驱体/花粉壳-核微球经550℃焙烧即可制得形状完整、大小约18μm的锐钛矿型TiO2中空微球.具有较窄的中孔结构,平均孔半径为1.9nm,比表面积为26.76 m2·g-1.     

四方排列有序Ag/TiO2空心微球的制备及光催化性能

采用低温垂直沉积法制备了聚苯乙烯(PS)胶体模板,由于低温下粒子热运动受到抑制,排列时发生位错,因此模板中存在大面积四方排列结构。然后采用化学镀法、溶胶-凝胶法在PS微球表面依次沉积银纳米粒子、纳米TiO2,最后高温煅烧除去模板制备了四方排列有序Ag/TiO2空心微球。通过扫描电镜(SEM)、X射线衍射(XRD)对样品进行表征。结果表明这种材料很好地保持了模板的四方排列,具有高度有序的纳米结构。选择降解甲基橙溶液来检验样品的光催化性能,并与纳米TiO2薄膜、四方排列TiO2空心微球的光催化性能进行比较,结果表明四方排列Ag/TiO2空心微球具有最佳的光催化性能。这是有序空心纳米结构和银纳米粒子的沉积共同作用的结果。     

用层层自组装法制备PS/SnO2核壳微球

利用层层自组装(LBL)技术制备了单层和多层吸附SnO2的PS/SnO2核壳微球,采用透射电镜(TEM)、场发射扫描电镜(FESEM)观察了产物的表面形貌,采用傅立叶变换红外分光光度计(FT-IR)分析了产物的结构,用热重分析仪(TGA)研究了不同吸附层产物的壳层比例,并研究了pH值、分散溶液、吸附层数对PS/SnO2核壳微球制备的影响,得到了最佳的制备条件.     

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.     

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.