氧氮玻璃连接Si_3N_4陶瓷的可行性研究

本文采用Y－Si－Al－O－N系氧氮玻璃对Si_3N_4陶瓷进行1450、1600℃保温30min的润湿实验和连接实验．结果表明，氧氮玻璃对Si_3N_4的润湿性较好，1450℃时两者的热膨胀系数差异明显，而1600℃时热膨胀系数差异减小，接头附近存在扩散区．氧氮玻璃可以连接Si_3N_4陶瓷．     

HIsmelt熔融还原高磷铁矿铁水含碳量影响因素研究

通过高温电阻炉对铁水含碳量的影响因素进行研究，考察碱度、温度、碳氧比等因素对铁水含碳量的影响规律。结果表明，铁水含碳量可以降到0．1％。当温度为1550℃、碱度为1．3、通氧时间为8min、保温时间为30min时，随着碳氧比的增加，铁水含碳量从0．022％增加到1．1％，其影响较显著；碱度在0．7～1．3之间，铁水含碳...     

O2,金属电极/YSZ界面的电化学研究

本文利用交流阻抗和直流极化的电化学方法，比较了200～500℃氧在Pt、Ag、Au、Ag－Pd四种化学镀电极上的扩散，350～600℃氧在金属电极／YSZ界面的电化学反应速度以及阴阳电荷传递系数；计算了350～600℃四种电极的界面阻抗；研究了400℃时O2在Ag－Pd电极界面的交换电流密度Io与氧分压Po2的定量关系．     

La0.6Sr0.4Co1-yFeyO3的混合导电性研究

采用直流四探针法和两端子电子阻塞电极交流阻抗谱研究了GNP法制备La0．6Sr0．4Co1-yFeyO3陶瓷的电子-离子混合导电性能．在室温-900℃范围内，La0．6Sr0．4CoO3的电子电导率随温度的升高而单调降低，其它样品的电子电导率随温度的升高在600℃附近达到最大值．La0．6Sr0．4Co1-yFeyO3陶瓷的氧离子电导率随温度的升高而增加．在相同温度下，随着Co／Fe比例的增加，La0．6Sr0．4Co1-yFeyO3陶瓷的电子电导率和氧离子电导率增加，电子导电活化能和离子导电活化能降低．氧离子迁移数随温度的升高而增加，随Co／Fe比例的增加而降低．     

乙基纤维素-二亚水杨基邻苯二胺钴共混富氧膜的研究

以压缩空气为气源，采用恒压体积法详细地研究了乙基纤维素膜及一系列不同比例的乙基纤维素－二亚水杨基邻苯二胺钴共混膜的富氧性能。结果表明，乙基纤维素－二亚水杨基邻苯二胺钴共混膜的富氧性能皆比乙基纤维素膜的富氧性能高，并且在０．５ＭＰａ，６０℃条件下，乙基纤维素－二亚水杨基邻苯二胺钴共混富氧膜（９４∶６）的富氧空气的渗透速率Ｐ及一级富氧浓度分别可达２．３４×１０６Ｂａｒｒｅｒ，４０％。     

铂修饰LSM电极对ZrO2氧敏特性的影响

以固相反应合成La0．7Sr0．3MnO3和YSZ，采用密封材料封装烧结LSM和YSZ，丝网印刷LSM作电极，制备极限电流型氧传感器。在500℃测试氧敏元件极限电流随氧气浓度变化的响应。测试结果表明，LSM电极经Pt修饰后，提高了氧敏元件信号的稳定性，与相同条件制备的Pt电极信号差别不大。     

乙基纤维—二亚水杨基邻苯二胺钴共混富氧膜的研究

以压缩空气为气源，采用恒压体积法详细地研究了乙基纤维膜及一系列不同比例的乙基纤维素－二亚水杨苛邻苯二胺钴共混膜的富氧性能。结果表明，乙基纤维素－二亚水杨基邻苯二胺钴共混的富氧性能皆比乙基纤维素膜的富氧性能高，并且在０．５ＭＰａ，６０℃条件下，乙基纤维素－二亚水杨基邻苯二胺钴共混富氧膜的富氧空气的渗透速率Ｐ及一级富氧浓度分别可达２．３４＊１０＾６Ｂａｒｒｅｒ，４０％。     

离子束溅射La0.5Sr0.5CoO3-δ薄膜的XRD和XPS研究

采用离子束溅射法在氧化钇稳定的氧化锆（YSZ）和铝酸镧（LaAlO3）上溅射RE0.5Sr0．5CoO3-δ薄膜，测试了薄膜的XRD、XPS谱、分析了表面微结构及化学状态。实验表明。随着热处理温度的升高。La0．5Sr0．5CoO3-δ薄膜在YSZ和LaAlO3上生长时有取向增强的趋势，并且晶粒度增大，晶格氧减少。氧空位增加。氧输运性能提高。当热处理温度为750℃时薄膜结晶度最好，晶粒度最大，氧输运性能最好。     

均四甲苯基中间相沥青纤维不熔化行为的研究

由均四甲苯出发，通过甲醛／Ｈ＋交联及进一步热处理合成了低软化点（２６０℃）、高Ｈ／Ｃ原子比（０．８６）、富含甲基基团、分子结构呈完全渺位缩合构型的中间相沥青。研究了该中间相沥青纤维的不熔化行为，发现它呈现出与一般石油系或煤焦油系中间相沥青的不同氧化行为，虽然具有较高的氧化反应性（在１５０℃开始与氧反应），但要实现纤维的完全不熔化却需较多量的氧与之交联。以０．２℃·ｍｉｎ－１（１７０℃～２６０℃）的升温速率升到２６０℃，恒温１８０ｍｉｎ得到的不熔化纤维的氧含量达１７．６％，其炭纤维强度可达２１００ＭＰａ。沥青呈现高氧化反应性的原因在于体系中含有较多量的甲基、亚甲基及孤立芳氢，它们引发了氧化反应的快速；中间相沥青的渺位缩合构型分子及小芳香核片的存在是不熔化过程需要多量氧的原因。     

Ba1-xLaxTiO3陶瓷的晶界再氧化机理研究

不同La施主掺杂浓度的BaTiO3陶瓷在H2／Ar的还原气氛下烧结后，再在氧分压PO2=260Pa的气氛（Ar和O2的混合气体）下进行氧化，通过氧流量计检测还原样品在再氧化过程的吸氧行为；用TEM分析样品氧化后显微结构的变化，测定了在不同最高氧化温度下氧化样品的PTCR效应以及复阻抗图谱．结果表明；氧流量计在升温阶段检测到三个不同行为的吸氧峰，峰Ⅰ（起始温度-250℃）为氧空位的填充过程；峰Ⅱ（起始温度-800℃）和峰Ⅲ（起始温度-1250℃）为还原相的氧化过程，具体来说，峰Ⅱ是通过晶界扩散提供氧使靠近晶界附近的区域被氧化；而峰Ⅲ是由晶格扩散过程控制，氧化过程从晶界逐渐向晶粒内部区域扩展，并伴随着富Ti的Ba6Ti17O40相的沉淀．在还原相向氧化相的转变过程中，于晶界处形成了两个具有晶界势牟的电结构单元而使陶瓷旱现强PTCR效应．     

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.     

The Influence of Nitrogen and Boron Implant into Silicon Substrate on the Phase and Internal Stress of c-BN Films

Cubic boron nitride(c-BN) film was deposited on a Si (100) substrate by the RF-magnetron sputtering.The mainly problems for fabrication of c-BN films are the low purity and high intrinsic compressive stress. In order to solve the two problems, the c-BN film with the buffer interlayer was deposited on the substrate which had been implanted with nitrogen and/or boron ions. The results show: the implantation of nitrogen ions can obviously increase c-BN content and reduce the internal stress slightly; while the implantation of boron shows no obvious improvement to the content of c-BN, which can reduce the internal stress in the film obviously. In addition, it is suggested that the implantation of nitrogen and boron shows the best result, which not only can increase the content of c-BN, but also reduce the internal stress in the c-BN film obviously.