低熔封接玻璃的研究进展

低熔封接玻璃是一种先进的焊接材料,由于其具有低的熔化温度和封接温度,优良的机械强度和化学稳定性,而在很多领域中得到广泛的应用,实现了玻璃、陶瓷、金属、半导体间的相互封接.综述了低熔封接玻璃的研究现状,展望了低熔封接玻璃向无铅化发展的趋势,指出了无铅低熔封接玻璃今后的研究方向.     

低熔封接玻璃组成及其发展

综述了低熔封接玻璃的组成特点，给出了大量低熔玻璃组成实例，批出了低熔封接玻璃的封接低温化和无铅化发展方向，磷酸盐玻璃是首选组成之一。新的制备工艺和新的玻璃形成体系将对封接玻璃发展起着十分重要的作用。     

中温固体氧化物燃料电池封接玻璃的研究进展

封接玻璃是中温固体氧化物燃料电池(IT-SOFC)的主要组成部分, 封接玻璃应同时具有适宜的热性能、化学性能、力学性能及与电池元件有良好的粘合能力, 防止SOFC在运行过程中气体的泄漏, 并保证玻璃在IT-SOFC工作温度及氧化气氛或燃料气氛下长期运行的热稳定性和封接玻璃与其它电池元件之间的界面稳定性。本文综述了关于IT-SOFC封接玻璃近十年的研究进展。从玻璃特性和封接玻璃与元件之间的界面反应的角度, 讨论封接玻璃的组分-结构-性能三者之间的关系, 提出了当前IT-SOFC封接玻璃研究的主要问题。     

不锈钢真空容器无尾封接生产用玻璃粉的研究

Pb-B-Si系低熔点玻璃是一种具有较好封接性能的玻璃粉,将其应用在不锈钢真空保温容器无尾封接中存在真空烧结时气泡消除缓慢、强度不够等问题。通过对Pb-B-Si系玻璃进行配方优化调节后,对玻璃粉进行性能检测,对焊点形貌等进行研究,采用扫描电镜分析了烧结层的微观结构。结果表明,优化后的配方体系为Pb-B-Si-ZnAl-CuO,其中Pb为83%,CuO为3.5%(质量分数)时,可以显著提高无尾封接时的强度,提高真空度。使用该玻璃粉生产的不锈钢真空容器的焊点饱满、光亮,接头强度好,无明显缺陷,显示其对不锈钢容器良好的封接强度。     

无铅低熔玻璃的研究及其进展

随着欧盟RoHS绿色指令的颁布和人类环保意识的增强，低熔点玻璃无铅化已越来越受到人们的重视。概述了无铅低熔玻璃的国内外研究现状，对无铅硼酸盐、磷酸盐、钒酸盐玻璃等体系的组成以及物化性能进行了较为全面的介绍，并分析了无铅低熔玻璃今后发展的难点和趋势。     

尖晶石面板投影管中屏与锥的封接研究

透明尖晶石陶瓷面板投影管的屏和锥采用了低熔点玻璃封接。给出了封接结构、所用屏、低熔点玻璃和锥的材料特性。分析了封接中材料匹配、浸润性以及再结晶等原理,叙述了封接工艺。检测证实,获得了性能良好的封接结果。     

He-Ne激光陀螺仪真空铟封结构应力分析与工艺优化

氦氖激光陀螺仪电极封接是维持其微晶玻璃谐振腔体真空环境的关键技术之一。研究分析了氦氖激光陀螺仪经典铟封接结构特点及电极铟封性能,应用弹塑性力学理论建立铟封结构的物理和数学模型。数值计算了铟封结构残余应力,得到了不同物性参数的残余应力变化规律,分析了铟丝环直径、铟合金化学计量比等参数对铟封残余应力的影响;优化了封接工艺参数,提高了封接强度及谐振腔真空铟封性能,使铟封接强度与真空气密性能满足氦氖激光陀螺仪长寿命的使用要求。     

低熔点玻璃封接技术

本文介绍了为测试吸气剂钡膜吸气性能等实验室用模拟试验玻壳低熔点玻璃到接件的结构、封接的原理、材料选择、清洁处理、封接工艺及温度控制。最后封接出性能优良的满足试验要求的封接件，其成品率可达９５％以上，我们的封接技术已达较高水平。     

固体氧化物燃料电池密封稳定性的研究进展

固体氧化物燃料电池(SOFCs)的密封质量直接影响其工作性能和寿命,是实现SOFCs商业化应用必须解决的课题之一.综述了玻璃/微晶玻璃封接、压缩封接和金属气密封接在耐久性和耐循环性方面的研究现状,从气密性、热失配补偿和化学稳定性方面分析了各方法的主要问题和解决办法,并展望了中低温SOFCs密封的发展方向.     

填料对铋锌硼低熔封接玻璃膨胀系数的影响及其微结构研究

在匹配封接中,为确保材料和结构在冷热反复循环的稳定性和耐久性,需考察封接材料与基体材料的膨胀系数在工作温度范围内的匹配性,以使封接应力尽可能小。一般来说,低熔点玻璃封接温度越低,膨胀系数越大。为满足低温封接,同时膨胀系数小的实际需求,常常在低温封接玻璃粉中添加低膨胀耐火填料,制成复合型低温焊料。本文对比研究了堇青石、锆英石、β-锂霞石及锂铝硅(LAS)微晶玻璃4种填料对Bi₂O₃-ZnO-B₂O₃低熔封接玻璃膨胀系数的影响,并估算了各自的有效模量。结果表明:在添加量相同的情况下,堇青石填料调节作用最为显著;β-锂霞石、锂铝硅微晶玻璃虽然本身的线膨胀系数为负,但调节效果不理想,与堇青石相比略差;锆英石的有效模量值最大,但因其自身密度大,膨胀系数也大,调节效果不及另外3种填料。     

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 ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

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