残余应力对Si3N4/S45C连接体强度的影响

本文主要就Si3N4／S45C连接体在插入软金属及附加热循环的情况下，使残余应力发生变化，而讨论其对抗弯强度的影响．其结果为：（1）Si3N4表面边缘处的拉伸应力是影响连接体强度的主要原因．（2）抗弯强度和残余应力具有σ0＝-1．63σ＋658．1的线性关系．（2）周期性热循环对连接体的残余应力及抗弯强度有较大的影响；即发生加工硬化等使残余应力上升，产生裂纹等导致强度下降．     

透氧膜用Ag-CuO高温密封材料的研究

研究了Ag-CuO密封材料在BaCo0.7Fe0.2Nb0.1O3-δ(BCFN)透氧膜材料上的润湿行为.对不同成分Ag-CuO在BCFN 透氧膜材料上的润湿角的研究结果表明,CuO的加入根本上改善了Ag的润湿性能;CuO加入量从0增加到4%(摩尔分数)的试验中,润湿角迅速减小,说明少量添加CuO即可明显改善Ag-CuO对BCFN透氧膜的润湿性能.对润湿表面SEM的分析结果表明,当CuO的加入量增加到8%(摩尔分数)以上,析出的CuO会明显侵蚀透氧膜材料.透氧膜管与 304不锈钢的封接试验结果证明,密封后透氧膜装置的具有很好的高温气密性.     

玻璃和云母复合封接SOFC电池堆性能

封接技术是影响平板式固体氧化物燃料电池(SOFC)发展的关键技术之一。实验中用云母和Bi2O3-BaO-SiO2-RxOy(R=K,Zn,Al2O3,etc.)玻璃复合,将电解质(氧化钇稳定氧化锆,YSZ)支撑的电池和金属连接体(SUS430不锈钢)封接在一起,对封接后电池堆的封接性能和开路电压以及各组元热膨胀性能进行测试。结果表明:云母在室温到720℃的平均热膨胀系数为8.5×10-6 K-1,Bi2O3-BaO-SiO2-RxOy玻璃20℃到520℃的平均热膨胀系数为11.0×10-6/K,与YSZ和金属连接体匹配。云母的层状结构可以缓解因热膨胀系数不同而产生的应力,在高温状态下云母还能起到固定软化玻璃的作用。通过气密性和电性能测试,在电池堆工作状态下气密性良好,在操作温度为800～900℃下运行28小时,电池堆的开路电压(OCV)维持在1.0V以上,复合封料及其两边材料中的元素没有明显扩散。因此,云母和玻璃Bi2O3-BaO-SiO2-RxOy复合封接技术可适用于高温SOFC的封接。     

固体氧化物燃料电池新型连接体材料的研究进展

连接体是固体氧化物燃料电池(SOFC)中的关键组件，对连接体的高性能需求一直制约着SOFC的商业化发展。随着SOFC的运行温度降低到800℃以下，廉价的高温抗氧化金属连接体材料取代掺杂铬酸镧(LaCrO₃)陶瓷的可能性大大增加。此外，为了优化连接体的性能，大量的导电/保护性涂层及新的复合材料也不断地涌现。综述了迄今为止连接体材料的发展现状，在对各种连接体材料以及涂层材料的性能和优缺点进行比较的同时，重点介绍了新开发连接体材料的研究进展，并对连接体材料的发展趋势进行了展望。     

真空热循环对单向M40J/5228A复合材料质损率和线膨胀系数的影响

对单向M40J/5228A复合材料进行了真空热循环试验 ( 93~413 K,10-5Pa)。分别测试了经不同次数真空热循环后材料的质损率及线膨胀系数。通过所建二维细观损伤模型分析了真空热循环次数对材料线膨胀系数曲线影响的原因。试验结果表明,随真空热循环次数的增加,质损率增大,并经约48次真空热循环后趋于平缓;横向线膨胀系数随温度升高而线性增大,真空热循环次数对其没有影响;纵向线膨胀系数在原始状态时随温度升高而线性减小,经113次真空热循环后表现出先下降后上升的非线性特征,真空热循环次数对纵向线膨胀系数的影响,与界面脱粘程度和残余应力的消除密切相关。      

正二十烷与膨胀石墨共改性三水合醋酸钠相变材料储热性能

为了克服三水合醋酸钠（CH₃COONa·3H₂O）作为相变储热材料在相变过程中存在的相分离现象,提高其热循环性能,采用简单的共混法将正二十烷（n-Eicosane）、多孔材料膨胀石墨（EG）与CH₃COONa·3H₂O复合制备了三元相变体系（n-Eicosane-EG/ CH₃COONa·3H₂O）,利用XRD、SEM、DSC等方法研究了复合相变体系的结构和储热性能。结果表明,利用正二十烷的包覆作用和EG的孔限域作用,可使n-Eicosane-EG/ CH₃COONa·3H₂O的热循环性能显著提高。     

SOFC合金连接体材料的研究进展

对固体氧化物燃料电池(SOFC)用合金连接体材料的研究进展进行了介绍,分别对镍基、铬基和铁基合金合金连接体材料的研究发展情况给予评述,对每种连接体材料的特点和存在的问题进行了详细的论述,并指明了各种合金连接体材料的今后发展趋势.最后着重指出铁基合金及其表面改性是今后连接体材料发展的主要方向.     

高性能封接玻璃的制备方法与应用

该文涉及玻璃生产的技术领域,尤其涉及玻璃的制备方法与应用。高性能封接玻璃包括以下重量百分比的组分:CaO为20%～50%、MgO为10%～40%、SiO_2为10%～40%、B_2O_3为1%～30%、ZrO_2为0%～5%、Al_2O_3为0%～5%、La_2O_3为0%～5%。高性能封接玻璃通过调整各组分的配比,调整了玻璃相和陶瓷相之间的比例,提高了玻璃的热膨胀系数,经实验测定玻璃的热膨胀系数为10.95 ppm/℃～11.65 ppm/℃,热膨胀系数较大,与固体氧化物燃料电池的连接体的常用材料不锈钢的热膨胀系数之间较为匹配,能降低因为二者热膨胀系数失配导致电池泄漏的风险。     

基于溶-凝胶制备工艺的SiO_2基复合相变材料研究综述

相变材料可吸收或释放潜热,从而拥有储能调温潜力。溶-凝胶工艺制备的SiO_2基体可为相变材料提供优良的骨架结构,改善相变材料的泄露问题。总结国内外相关文献,介绍了溶-凝胶制备工艺及SiO_2基复合相变材料的形貌。阐述了SiO_2基体与相变材料间的化学相容性、SiO_2基体对相变材料结晶性能的影响以及SiO_2基复合相变材料的热物性、热循环稳定性和储/放热性能。最后对引入碳纤维/碳纳米管和金属/金属氧化物粒子等功能型材料,以增强其导热性能及光热转化能力的两类增强型SiO_2基复合相变材料进行了概述。     

真空热循环对空间级缩合型硅橡胶拉伸性能的影响

对空间级缩合型硅橡胶KH－X－B进行了真空热循环试验（123－403K，10^-5Pa），测试了热循环前后材料的质损率，拉伸性能，热膨胀性能，讨论了循环过程中的应变滞后效应和附加残余应变以及它们对材料的强化作用，结果表明，材料质损率随循环次数增加而提高后趋于平缓，室温及高温拉伸强度随循环次数的增加是先增强而后下降，循环过程中发生应变滞后现象，且第一次循环后产生附加残余应变，206次循环后残余应变消失，材料强化，400次循环后重新产生残余应变，材料强度下降。     

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.     

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.……     

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.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

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.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.