气凝胶薄膜制备的研究进展

气凝胶薄膜作为一种具有独特特性的薄膜材料,在光学、热学、声学、微电子等领域受到广泛关注。概述了气凝胶薄膜的溶胶制备和溶胶镀膜制备工艺,对比了气凝胶溶胶的酸催化、碱催化和酸碱两步催化等制备方法;介绍了浸渍提拉法、旋转镀膜法等溶胶镀膜方法;综述了溶胶制备和镀膜等工艺条件对气凝胶薄膜结构和性能的影响及其研究进展,指出酸碱两步法和金属等杂化是提高气凝胶薄膜性能的有效途径;最后展望了气凝胶薄膜材料的发展和应用前景。     

化学法制备掺铝氧化锌透明导电薄膜的研究进展

综述了掺铝氧化锌(ZAO)透明导薄膜的化学法制备技术、及应用前景,重点介绍了溶胶-凝胶法制备ZAO薄膜的热处理条件、溶胶浓度、陈化时间、加水量以及稳定剂种类和用量等方面对薄膜结构和性能的影响.     

锆钛酸铅(PZT)薄膜的制备及其改性研究

文章综述了锆钛酸铅(PZT)薄膜的主要制备方法,其中包括射频磁控溅射法、脉冲激光沉积法、溶胶-凝胶法和金属有机化学气相沉积法。讨论了不同工艺参数对于PZT薄膜的结构和性能的影响,并针对PZT薄膜出现的疲劳现象进行掺杂改性,探讨提高其抗疲劳性能的途径。     

溶胶-凝胶法制备ITO透明导电薄膜的研究进展

ITO透明导电薄膜以其优良的透明导电性能在平面液晶显示(LCD)、电致发光(EC)等多个领域得到了广泛的应用.制备ITO薄膜的方法很多,其中采用溶胶-凝胶法制备ITO透明导电薄膜具有成本低,设备简单,工艺可控,有利于大面积成膜等优点,因而受到了广泛的关注.较详尽地介绍了ITO薄膜的透明导电机理、溶胶-凝胶法的工艺特征,并初步论述了溶胶-凝胶法制备ITO透明导电薄膜的应用和发展前景.     

Ta_2O_5薄膜制备的研究现状及进展

Ta2O5薄膜具有很好的电学性能和光学性能,制备方法种类繁多,如溶胶-凝胶法(Sol-gel)、化学气相沉积法、电子束蒸发技术、溅射法、Ta层阳极氧化或热氧化法、离子辅助沉积法(IBAD)、原子层沉积法(ALD)等。评述了现有各种制备方法的优缺点,综述了Ta2O5薄膜各种方法制备的条件、薄膜的功能性质等,并评析了金属有机化合物为前驱体制备性能优良的Ta2O5薄膜的前景。     

溶胶-凝胶法制备AZO薄膜的研究进展

综述了采用溶胶-凝胶法制备AZO薄膜的进展,阐述了影响AZO薄膜光电特性的主要工艺参数,分析了陈化时间、热处理工艺、铝掺杂量、催化剂种类及薄膜厚度因素等对AZO薄膜结构、光电性能的影响,指出了溶胶-凝胶法制备AZO薄膜的优势与不足,展望了未来的研究方向.     

不连续金属薄膜制备工艺的研究进展

不连续金属薄膜在隐身方面具有特殊用途.阐述了溶胶-凝胶法(Sol-gel)制备金属-介质复相薄膜的研究进展,重点介绍了金属-介质复相薄膜的诱导热处理工艺,最后讨论了制备不连续金属薄膜存在的问题.     

溶胶-凝胶法制备氧化硅光学减反射膜

综述了溶胶-凝胶光学减反射膜的应用背景及光学原理,系统讨论了溶胶-凝胶氧化硅减反射膜的完整制备工艺以及薄膜在使用过程中的主要性能评价指标,最后展望了薄膜的未来发展趋势。     

溶胶-凝胶法制备太阳能薄膜的研究及展望

介绍了溶胶-凝胶法的反应机理、工艺过程,着重介绍了太阳能光电/光热转换的原理、薄膜的分类以及最新研究现状,指出采用溶胶-凝胶法可获得高效率太阳能薄膜,并展望了溶胶-凝胶法在太阳能薄膜制备方面的发展趋势及应用前景.     

金属氧化物半导体薄膜气敏机理研究进展

气体传感器的核心介质为气敏薄膜,而薄膜本身的特性有关键的影响,主要体现在薄膜微观结构如晶粒尺寸、膜厚、空隙率和有效表面积等方面。溶胶-凝胶法由于有方法简单及成膜温度低等优点,得到了广泛研究与应用。本文综述了溶胶-凝胶法制备的金属氧化物薄膜微纳结构与气敏机理进来的研究进展,结果表明最佳的晶粒尺寸约为10nm,最佳膜厚约为110 nm。在晶粒尺寸控制方面,通过控制煅烧温度与时间及在溶胶-凝胶过程中加入不同的添加剂,可有效优化晶粒尺寸提高灵敏度。最后,从能带结构角度总结了气敏传感器的电学特性及荷电传输机理,讨论了热电子发射理论和电子隧穿理论起主导作用时的薄膜微纳结构。     

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.     

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.     

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 ...     

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     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.