LB薄膜技术在尖端材料制备中的应用

LB(Langmuir-Blodgett)薄膜技术可以在分子水平上进行材料设计,是实现分子工程的重要手段.LB膜可以方便地沉积纳米级的功能微粒和薄膜,也是制备梯度功能材料的方法之一.简要综述了LB薄膜技术在功能晶体、纳米半导体及铁电体等尖端材料制备中的应用,并展望了其相关应用研究的重要前景.     

新型铜硫系薄膜太阳能电池材料制备的研究进展

薄膜太阳能电池提供了低成本、大面积的无碳发电应用前景,迅猛发展的纳米科技为高转换效率薄膜太阳能电池的低成本制造提供了新途径。新型铜硫系半导体Cu_2ZnSnS_4(CZTS)薄膜材料具有禁带宽度与太阳辐射匹配性好、光吸收系数大、元素丰度大、价格便宜、无毒等优点,因此将成为最具发展前景的薄膜太阳能电池材料。讨论与分析了CZTS薄膜和纳米晶材料的制备及由这些材料制备绿色、低成本、高效率新型太阳能电池的研究进展。     

PCVD法制备硅系纳米复合薄膜材料

纳米复合薄膜材料由于具有传统复合材料和现代纳米材料两者的优点,成为重要的前沿研究领域之一.其中半导体纳米复合材料,尤其是硅系纳米复合薄膜,由于具有独特的光电性能,加之与集成电路相兼容的制备技术,有着广泛的应用前景.近年来关于纳米复合薄膜的研究不断深入,但仍有许多问题没有完全解决.本文围绕硅系纳米复合薄膜的材料特点,说明了等离子体化学气相沉积(PCVD)技术的工作原理和装置结构,以及该技术在硅系纳米复合薄膜制备中的独特优点.并以氮化硅薄膜为重点,介绍纳米复合薄膜材料的PCVD制备技术.文章最后对硅系纳米复合薄膜的在光电技术等各个领域的应用前景做了一些展望.     

薄膜电极技术及其应用进展

伴随电化学学科的发展，薄膜电极制作技术已经与最新的材料制作技术链接。结合薄膜电极在军事、能源、环境保护、催化反应以及生物化学等领域的应用，综述了薄膜电极分类、各种电极的制备技术，特别是ITO电极、纳米晶体管电极和导电高分子薄膜晶体管电极，在电子纸等显示器件方面的应用。认为复合电极是未来的发展方向，分子自组合有序膜技术在薄膜电极加工方面用途广泛。     

高附加值产品助推信息产业发展

电子信息材料是指在微电子、光电子技术和新型元器件基础产品领域中所用的材料,主要包括单晶硅为代表的半导体微电子材料;激光晶体为代表的光电子材料;介质陶瓷和热敏陶瓷为代表的电子陶瓷材料;钕铁硼永磁材料为代表的磁性材料;光纤通信材料;磁存储和光盘存储为主的数据存储材料;压电晶体与薄膜材料;贮氢材料和锂离子嵌入材料为代表的绿色电池材料等。这些基础材料及其产品支撑着通信、计算机、信息家电与网络技术等现代信息产业发展。近年来,电子信息材料总体发展趋势向着大尺寸、高均匀性、高完整性,及薄膜化、多功能化和集成化方向发展。当前的研究热点和技术前沿包括柔性晶体管、光子晶体、SiC、GaN、ZnSe等宽带半导体材料为代表的第三代半导体材料、有机显示材料及各种纳米电子材料等。     

金属有机化合物在制备半导体材料中的应用

简单介绍了金属有机化合物的制备及其在光电薄膜．陶瓷薄膜及纳米级半导体材料中的应用。     

纳米电子器件呼唤真空化学研究

纳米电子器件是微电子器件发展的下一代 ,现有微电子器件的主要材料是极纯的硅、锗和镓砷等晶体半导体。纳米电子器件有可能是以有机或有机 /无机复合晶体薄膜为主要材料 ,要求纯度更高 ,结构更完善。真空制备的清洁环境 ,有希望加工组装出纳米电子器件所要求的结构。故本文建议开展真空化学研究     

生物拟态法合成纳米半导体材料的研究进展

综述了生物拟态法制备纳米半导体材料的研究概况，结合最新的研究成果阐述了这种新的制备技术在合成新型功能材料上的应用和旺盛的生命力。     

单一取向Cu2O纳米棒的一种工业制备技术

作为一种直接带隙p型半导体材料,Cu2O在很多工业领域都有良好的应用前景,而Cu2O纳米棒因其一维纳米几何而具有更诱人的性能。然而缺少低成本的制备方式限制了Cu2O纳米棒的工业应用。为了解决这个问题,我们探索了热蒸发掠射角沉积加后退火处理的制备方法,成功获得了取向一致的多晶Cu2O纳米棒阵列薄膜,为Cu2O及类似材料的纳米棒薄膜的大规模工业化生产找到了一种低成本的制备技术。     

有机溶剂热生长晶体及其应用

介绍了有机溶剂热生长技术在金属碲,硒多聚物合成中的应用,并讨论了这类化俣物的结构特征,及其在制备纳米级半导体薄膜,催化剂载体和离子交换材料方面的应用前景。     

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...