包覆型ZrO2(3Y)粉体研制

用微波法制备单分散、纳米水合二氧化锆，利用异相成核工艺在水合二氧化锆粒子表面均匀包覆一层Y（OH）₃，制备出包覆型ZrO₂（3Y）粉体先驱体．最后对煅烧ZrO₂（3Y）粉体进行相结构分析，发现在室温下包覆型ZrO₂（3Y）粉体中无m－ZrO₂存在．结果表明；利用包覆的方法能将Y₂O₃均匀地加入到ZrO₂中，提高ZrO₂（3Y）粉体中亚稳定t－ZrO₂的含量．     

高分散、均混合Al2O3-SiC-ZrO2(3Y)水悬浮液

用微波法制备主水合二氧化锆,通过包覆工艺,将Ｙ（ＯＨ）３均匀地包覆在水合二氧化锆粒子表面,制备出ＺＯ２（３Ｙ）的先驱体。然后用聚甲基丙烯酸铵（ＰＭＡＡ－ＮＨ４）对α－Ａｌ２Ｏ３、纳米ＳｉＣ及包覆水合二氧化锆表面的改性。     

高分散、均混合Al2O3-SiC-ZrO2(3Y)水悬浮液

用微波法制备纳米水合二氧化锆, 通过包覆工艺, 将Y(OH)3均匀地包覆在水合二氧化锆粒子表面, 制备出ZO2(3Y)的先驱体. 然后用聚甲基丙烯酸铵(PMAA-NH4)对α-Al2O3、纳米SiC及包覆水合二氧化锆表面改性. 使三种单相水悬浮液在pH=9.0时, 粒子表面电性相同, 且有良好分散状态. 从而制备出高分散、均混合Al2O3-SiC-ZrO2(3Y)先驱体水悬浮液.     

Al2O3-ZrO2(3Y)-SiC纳米复合材料的制备及性能

本文研究了非均相沉淀法制备Al2O3－ZrO2（3Y）－SiC复合粉体的工艺过程,认为粉体的理烧温度是至关重要的,热压烧结得到了致密的Al2O3－ZrO2（3Y）－SiC纳米复合材料,ZrO2的加入对烧结温度的影响不大．通过TEM观察,SiC颗粒均匀分散于材料中,大的ZrO2颗粒位于Al2O3晶粒间,小的圆形ZrO2颗粒位于Al2O3晶粒内,一部分Al2O3晶粒呈非等轴状．80Wt％Al2O3－15wt％ZrO2－5Wt％SiC纳米复合材料的抗弯强度可达555MPa,韧性为3.8MPa．m1／2.     

用保护共沉淀法制备纳米ZrO2(Y2O3)粉体

用Tween-80保护共沉淀法制备了ZrO2(Y2O3）纳米粉体，用差热分析，热重分析，X射线衍射及透射电子显微镜等技术研究所了粉体的特征，结果表明：在700℃燃烧0.5h后ZrO2(Y2O3)粉体的平均粒径为3－9nm，比表面为128.5-134.5m^3g^-1,在1250℃煅烧8h后ZrO2(Y2O3)粉体已完全形成了立方相的ZrO2L大溶体，并且有非常好的烧结性能。     

高分散、均混合 Al2O3-SiC-ZrO2(3Y)水悬浮液

用微波法制备纳米水合二氧化锆, 通过包覆工艺, 将Y(OH)     

Al2O3和Y2O3包覆的SiC复合粒子制备

本文利用非均匀成核法,将Al（OH）3和Y（OH）3均匀地包匿在SiC粒子表面,制备出被覆Al2O3和Y2O3的SiC复合粒子．包覆Al（OH）3的SiC粒子,其等电点IEP的pH=3．4移至pH=7.3,再用Y（OH）3包覆表面被覆Al（OH）3的SiC复合粒子后,其等电点IEP又从pH=73移至pH=8.6左右．并且表面包覆的SiC粒子,其水悬浮液流变性质发生了变化．经盐酸滴定表明,涂层物质的包覆率可达95％以上．     

(Y,Gd)2O3:Eu(YGO:Eu)纳米粉体合成及透明陶瓷制备

研究以碳酸氢铵作为沉淀剂制备Y1．34Gd0.6Eu0.06O3（YGO：Eu）纳米粉体的工艺，并采用真空烧结制备了YGO：Eu透明陶瓷．实验结果表明：以硝酸盐为母盐，以碳酸氢铵为沉淀剂，在本研究试验条件下获得的YGO先驱物为晶态的水合稀土碳酸钇钆正盐．先驱物在600℃煅烧后可以得到立方晶型的YGO粉体．煅烧温度对粉体的颗粒尺寸及尺寸分布有影响，1100℃煅烧所获得的粉体由粒径-100nm的球形颗粒组成，颗粒尺寸分布均匀，粉体具有较好的烧结性能．采用所制备的YGO：Eu纳米粉体，在1670℃真空烧结2h可获得透光性良好的透明陶瓷，样品在可见光区的最高透过率可达74．6％，高于相同工艺条件下制备的氧化钇透明陶瓷．     

纳米TiO2的原位包覆及分散性研究

采用水热合成法制备纳米TiO2粉体,以自制的1100分散剂对粉体进行原位包覆和后包覆,考察了分散剂用量、pH值对包覆体系分散性的影响,利用XRD和TEM进行结构表征和形貌观测,并采用分光光度法对纳米TiO2粉体水分散体系稳定性进行了检测,在此基础上制备了纳米TiO2／有机复合涂膜．研究表明：原位包覆制备的纳米TiO2中,锐铁矿相的质量分数为100％,分散较均匀,纳米TiO2粉体的平均粒径约为20nm;分散剂用量为8．0％、pH值为3和10时,其水溶液分散稳定性较高;后包覆制备的纳米TiO2粉体由锐钛矿相（73％）和金红石相（27％）构成,纳米TiO2粒子处于团聚状态,无明显颗粒形态;涂膜经自然光照射24h后,对大肠杆菌的杀灭率为99．8％;良好的分散工艺和有效的分散剂可充分发挥纳米TiO2的光催化功能．     

Fabrication of ZrO2/AI203 green body through gelcasting process using low-toxicity monomer DMAA

采用低毒的单体N,N-二甲基丙烯酰胺（DMAA）制备了氧化锆增韧氧化铝（ZrO2／A12O3）坯体。讨论了分散剂的用量、ZrO2／Al203浆料的pH值、粉体中Zr02含量、粉体所占浆料的固相体积分数、球磨时间、预混液中DMAA的浓度（质量分数）对ZrO2／Al203浆料黏度的影响。并研究了注凝成型ZrOz／Al203坯体的性能和显微结构。结果表明,当浆料pH值为9,分散剂的添加量为ZrO2／A1203粉体质量的0．6％,球磨时间为6h,ZrO2／Al203浆料具有最小的黏度。固相体积分数的提高和DMAA加入量的增大都会提高ZrO2／A12O3浆料的黏度,ZrOz的加入会降低浆料的黏度。用DMAA制备得到的ZrO2／Al203坯体结构均匀,抗弯强度达到25MPa。     

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.