CBS玻璃/堇青石陶瓷复合材料制备与性能

采用电子陶瓷工艺制备了一系列钙硼硅玻璃／堇青石陶瓷复合材料，堇青石含量分别为50％，60％，70％和80％（质量分数）。对复合材料进行了X射线衍射分析、扫描电镜（SEM）观察和性能测试。结果表明：复合材料的介电常数和热膨胀系数随陶瓷含量的增加而减小，显微硬度随陶瓷含量的增加而增加。堇青石的加入抑制了钙硼硅玻璃中石英的析出，并生成了新相钙长石，其数量随堇青石和烧结温度的增加而增加，但它没有恶化复合材料的物理性能。所制得的复合材料具有高的相对密度（≥96％）、低的介电常数（～6）、低的介电损耗（0.3％～0．5％）、低的热膨胀系数（4．2×10^-6℃^-1～5．2×10^-6℃^-1）和低的烧结温度（≤950℃），有望用作介电材料和基板材料。     

低温烧结玻璃陶瓷复合材料的性能

采用电子陶瓷工艺制备了一系列玻璃陶瓷复合材料，对复合材料进行了X射线衍射分析、扫描电镜（SEM）观察和性能测试。结果表明：复合材料的介电常数和热膨胀系数随硅灰石含量的增加而减小，显微硬度随硅灰石含量的增加而增加。随着硅灰石量的增加，复合材料烧结致密化温度移向高温。硅灰石的加入抑制了玻璃中方石英和钙硼石的析出，有利于硅灰石相的形成。当硅灰石含量为40％时所制得复合材料的性能最佳，即有高的相对密度（96％）、低的介电常数（5）、低的介电损耗（约0．2％）、低的热膨胀系数（约7．1×10^-6/℃）和低的烧结温度（950℃），有望用于基板材料。     

硼硅酸玻璃对CaO-B2O3-SiO2玻璃陶瓷结构和性能的影响

采用在CaO-B2O3-SiO2（CBS）玻璃中添加硼硅酸玻璃的方式制备了低温烧结的CBS复相玻璃陶瓷,系统地研究了其对CBS玻璃陶瓷10MHz下的介电常数及热膨胀系数的影响规律。利用DSC,XRD和SEM微观结构分析方法,研究了试样的性能与结构的关系。研究结果表明：硼硅酸玻璃与CBS玻璃具有很好的相容性,硼硅酸玻璃的添加量在0～40%（质量分数,下同）的范围内均可在850℃烧结。硼硅玻璃能有效降低体系的介电常数,实现介电常数在5.6～6.6范围内可调;硼硅玻璃的添加量小于20%时,膨胀系数增加幅度较小,随着硼硅玻璃量的增加,膨胀系数显著增大,其原因是随着硼硅酸玻璃添加量的增加,生成了具有低介电常数、高膨胀系数的-αSiO2。     

低温烧结BaO-Sm2O3-TiO2系微波介质陶瓷材料的研究

利用传统的固相法制备BaO-Sm2O3-TiO2系陶瓷。通过复合添加氧化物ZnO、CuO和玻璃料Bi2O3-B2O3-ZnO-SiO2（BBZS），系统的烧结温度降至900℃。研究了玻璃料的添加量对介电性能的影响。按BaSm2Ti4O12＋1％（质量分数）ZnO＋1％（质量分数）CuO＋x％（质量分数）BBZS（0＜x≤30）配方，当x=25，预烧温度为1100℃和烧结温度为900℃时，有以下的微波特性：εr=60．51，Qf=2256GHz，τf=15．02×10^-6/℃，该陶瓷材料有望与纯Ag电极共烧，应用到LTCC领域。     

PbTiO_3微晶玻璃陶瓷的结构和热释电性能研究

采用溶胶－凝胶方法在Ｐｂ－Ｔｉ－Ｂ－Ｓｉ－Ｏ凝胶玻璃体系中,析出了ＰｂＴｉＯ３微晶．ＤＴＡ和Ｘ－ｒａｙ衍射分析表明,随玻璃含量的增加,析晶温度升高．热释电测试结果说明,随着玻璃含量的增加,热释电系数增大;随烧结温度的升高,ＰｂＴｉＯ３微晶玻璃陶瓷的热释电系数也随之增大．介电温谱的测量则显示,ＰｂＴｉＯ３陶瓷与ＰｂＴｉＯ３微晶玻璃陶瓷具有明显的差异．     

固相法制备BaTiO3基细晶陶瓷粉体

通过传统的固相法制备BaTiO3基细晶陶瓷粉体，讨论了在预烧温度和烧结温度相同的情况下，探讨不同施主元素的添加量对陶瓷晶粒及电性能的影响；在预烧温度和烧结温度相同的情况下，探讨不同受主杂质对陶瓷晶粒及电性能的影响；在施、受主掺杂量及烧结温度相同的情况下，探讨不同的预烧温度对陶瓷晶粒及电性能的影响．为了制备高升阻比、晶粒细小的BaTi03陶瓷，选取的材料配方为Ba1.0Ti1.01O3＋0.4％（摩尔分数）Y2O3＋0.03％（摩尔分数）Mn（NO3）2＋2％S102，粉体在1200℃预烧，保温2h，样品在1280℃烧成。上电极后测得常温电阻率为4937Ω·cm，升阻比为7．116×10^3，温度系数为14．03％，居里温度为128．4℃．     

Si-B-O系BST玻璃陶瓷制备及介电弥散研究

采用硝酸钡、硝酸锶、钛酸丁酯、正硅酸乙脂和硼酸三正丁脂为原料的溶胶凝胶方法制备了Si-B-O系BaxSr1-xTiO3玻璃陶瓷。通过差热分析(DTA)、热失重(TG)、X射线衍射(XRD)分析Si-B-O系BST玻璃陶瓷超细粉体合成过程及其相结构变化。采用X射线衍射(XRD)、扫描电子显微镜(SEM)描述Si-B-O系BST玻璃陶瓷烧结体的相结构和显微组织结构变化。阻抗分析仪测量Si-B-O系BST玻璃陶瓷的-50～100℃介电温谱。实验结果表明：Si-B-O系BST玻璃陶瓷粉体的相结构为立方钙钛矿相结构,其合成温度为700℃．不存在第二相。Si-B-O系BST玻璃陶瓷的烧结温度低于传统工艺。Si-B-O系BST玻璃陶瓷的显微结构呈细晶结构。Si-B-O系BST玻璃陶瓷的介电常数ε随着烧结温度升高而增大．介电损耗tgδ随测试温度的增加而降低。随着晶粒平均尺寸的减小．Si-B-O系BST玻璃陶瓷样品的介电峰变低．平坦．宽化．存在介电峰弥散化的现象。     

LCMAS微晶玻璃／Y－TZP复相材料

本工作对ＬＣＭＡＳ微晶玻璃／Ｙ－ＴＺＰ复相材料在不同的烧结温度下所出现的晶相进行了研究，发现材料在烧结温度下，Ｙ－ＴＺＰ中的ＺｒＯ２与微晶玻璃中的ＳｉＯ２发生化学反应生成锆英石（ＺｒＯ２·ＳｉＯ２），少量Ｙ－ＴＺＰ的加入起不到相变增初作用．由于Ｙ－ＴＺＰ起到微晶玻璃晶核剂的作用，仍能使材料的抗折强度和断裂韧性得到大幅度的提高．当Ｙ－ＴＺＰ含量为９５ｗｔ％时，复相材料的抗折强度和断裂韧性分别为６３１ＭＰａ和８．４ＭＰａ．ｍ１／２．     

空心玻璃微珠造孔制备多孔莫来石陶瓷及其性能EI北大核心

以煤矸石和铝矾土为原料,空心玻璃微珠为造孔剂,采用压制成型烧结制备多孔莫来石陶瓷。研究空心玻璃微珠添加量和烧结温度对物相组成、显微结构、抗弯强度和耐酸碱腐蚀性能的影响。结果表明:提高空心玻璃微珠添加量可以增大多孔陶瓷气孔率;空心玻璃微珠的添加可以促进莫来石相的形成,降低烧结温度。在一定温度范围内提高烧结温度可以增大气孔率,但烧结温度超过1350℃后气孔率开始下降。保持Al_(2)O_(3)∶SiO_(2)摩尔比为3∶2,调整空心玻璃微珠添加量至1.68%(质量分数),在1350℃保温2 h烧结条件下可获得气孔率为33.23%、抗弯强度为56.41 MPa的多孔莫来石陶瓷,其耐酸碱腐蚀性能良好。     

NbO3-LiNbO3无铅压电陶瓷的烧结特性和压电性能研究

采用传统陶瓷烧结工艺制备了（1-x）（K0．5Na0．5）NbO3-xLiNbO3无铅压电陶瓷，研究了陶瓷的结构、烧结特性及电性能特征．制备的（K0．5Na0．5）NbO3-LiNbO3陶瓷为单一的钙钦矿结构，室温下其相结构随LiNbO3含量增加逐渐由正交相向四方相转变，显微结构也由于LiNbO3含量的不同而表现出很大差异．与（K0．5Na0．5）NbO3陶瓷相比，（K0．5Na0．5）NbO3-LiNbO3陶瓷的烧结温度降低，烧结特性得到改善．（K0．5Na0．5）NbO3-LiNbO3陶瓷表现出优越的压电性能，其中0．94（K0．5Na0．5）NbO3—0．06LiNbO3（x=0．06）陶瓷的压电常数d33达到205pC／N，机电耦合系数kp为40．3％，kt达到49．8％．     

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