大面积3D有序介孔二氧化钛薄膜光子晶体制备与性能研究

介绍了大面积有序反蛋白石结构介孔二氧化钛薄膜光子晶体制备与性能研究的进展.为了保证二氧化钛骨架结构的稳定性和有序度,从而使氧化钛介孔薄膜达到大面积结构均匀,在介孔薄膜制备过程中采用了几种新的工艺方法,其中包括二氧化硅晶体模板的应用和用NaOH溶液代替常用的HF溶液作为模板去除剂.制备的介孔二氧化钛薄膜光子晶体的面积达到厘米尺寸,二氧化钛骨架的填充率达到17.4%,薄膜制备过程中的收缩率<3%.薄膜透射光谱研究结果表明,这种大面积3D有序的反蛋白石结构介孔二氧化钛薄膜具有非常优良的光子带隙特性,有望成为一类具有非常好的发展和应用前景的光子晶体材料.     

THF改性反胶团微乳液法制备纳米TiO2多孔薄膜的性能

四氢呋喃(THF)改性反胶团微乳液法可制备出粒径小而均匀并呈球形的纳米非晶态TiO2多孔薄膜.将所制备的非晶态TiO2薄膜应用于染料敏化太阳能(DSC)电池,并与P25纳米晶粉体制备的晶态TiO2薄膜及其DSC性能进行对比.结果显示,虽然非晶态TiO2多孔薄膜的染料吸附量明显低于P25纳米晶薄膜,但由于微观结构和制备方法的不同,所组装的DSC光电转换效率达到4.68%,与P25纳米晶薄膜的光电转换效率相当.研究结果表明,由于相比P25纳米晶TiO2薄膜,非晶态TiO2多孔薄膜制备工艺简单,用于DSC具有明显优势.     

介孔氧化钛的溶剂热合成及其光催化性能

以嵌段共聚体P123为结构导向剂,乙醇为溶剂,溶剂热合成了粒径在微米级的锐钛矿介孔氧化钛.利用透射电镜(TEM)、N2吸附、X射线衍射(XRD)和扫描电子显微镜(SEM)等表征手段研究了晶化时间和前驱物配比对合成产物孔结构和结晶状态的影响.所得的锐钛矿氧化钛晶粒具有较大的比表面积和纳米级孔道结构.以此产品作为光催化剂对二氯苯酚具有较强的光催化效果.在低浓度原料配比下,150℃晶化10d得到的介孔氧化钛具有接近于商业化纳米氧化钛P25的降解能力.     

有序介孔纳米膜的形成机理及在电池中的应用展望

阐述目前制备有序介孔薄膜所用的模板剂(离子型和非离子型表面活性剂)制备介孔薄膜的研究进展,并且就有关现今粉体介孔材料与有序介孔纳米薄膜的形成条件、制备机理的研究方法进行总结,最后展望有序介孔结构薄膜材料在电池器件领域中潜在的应用价值.     

介孔基纳米复合薄膜研究进展

基于介孔薄膜的有序纳米孔结构及一致孔径,通过客体组分的高效负载,开展介孔基纳米复合薄膜的制备科学与性能研究是近年来材料、化学、物理领域的共同热点。首先综述了国内外近年来在介孔薄膜及介孔基纳米复合薄膜方面的工作进展,重点阐释了通过模板置换、离子交换、有机硅烷表面修饰等新方法设计,以及在介孔薄膜中进行金属氧化物、贵金属、半导体纳米粒子高效负载的研究结果;在此基础上,进一步综述了介孔基纳米复合薄膜有关非线性光学特性的研究进展,尤其是材料制备过程中的外场环境(磁场、微重力等)对纳米复合材料非线性光学性质的可能影响。     

阳极TiO2薄膜两步施加电压法制备参数对其形貌的影响

Ti的硫酸阳极氧化中硫酸的腐蚀性不足以溶解TiO2阻挡层,采用高温、高电压又会使膜纳米孔的孔径大于200 nm,使其应用范围受到限制.采用两步施加电压的方法,对钛阳极进行阳极氧化处理,以期在不同的工艺条件下制备具有不同孔径和孔密度的氧化钛薄膜.使用扫描电子显微镜考察了初始电压、终态电压、电解液温度、氧化时间等工艺参数对阳极氧化钛薄膜形貌的影响.结果表明,初始电压对氧化钛薄膜形貌的影响是通过改变电解液/阻挡层之间的界面条件来实现的;随着阳极氧化时间的延长纳米孔的孔径减小,孔密度增大;提高电解液的温度不影响纳米孔的形成过程,但对氧化钛薄膜的生长过程产生了比较大的影响.     

TiO2介孔薄膜制备及光电化学性能

采用溶液-凝胶法分别制备TiO2介孔薄膜和TiO2纳米晶薄膜,其中TiO2介孔薄膜的制备过程中采用PVC-g-POEM为模版。XRD分析结果表明,两者的晶体结构无法明显变化,均为锐钛矿,SEM分析表明TiO2介孔薄膜的孔洞大小及分布均匀。经过染料敏化处理组成光阳极后,TiO2介孔薄膜的吸光性,及光电化学性能明显增强。     

定向介孔薄膜制备的研究进展

定向介孔薄膜是指内部孔道沿着同一方向定向排列的介孔薄膜. 本文就定向介孔薄膜的制备方法特别是近几年内的进展进行了回顾和评述, 按形成介孔薄膜的机理总结出三类制备介孔薄膜的方法, 并且分析了薄膜制备过程中的影响因素, 从薄膜定向性的角度对制备介孔薄膜的研究进行了分析与展望, 提出了今后制备定向介孔薄膜的发展方向和研究热点.     

微波等离子体化学气相沉积方法制备纳米金刚石薄膜

为了制备出大面积均匀连续的纳米金刚石薄膜,并探索温度、气氛等条件对最终生长出的纳米金刚石薄膜样品的影响,使用微波等离子体化学气相沉积(MPCVD)方法,改变CH4、H2、Ar气体比例以及衬底温度,在不同生长条件下制备了5组金刚石薄膜样品.5组样品分别使用ESEM和拉曼光谱进行成膜质量、形貌、结构以及组分的表征,分析了不...     

可控粒径mTiO2/mSiO2及其中空结构mSiO2微球制备

近年来,mTiO_2/mSiO_2复合材料和中空结构介孔二氧化硅在生物催化、药物控释等领域展现出良好的应用前景。在乙醇体系下,以十六胺为模板剂,运用自组装原理制备出介孔氧化钛;并运用晶种法,通过改变TEOS量、模板剂用量、异丙醇和水的用量制备出一种粒径大小在0.80~1.92μm范围内可控的mTiO_2/mSiO_2复合材料;最后在乙醇体系中加入盐酸冷凝回流制备出中空结构介孔二氧化硅微球。通过透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线衍射(XRD)对合成的产物进行表征。     

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.     

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.     

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...     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

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.     

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.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from