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Fabrication of ZrO2/AI203 green body through gelcasting process using low-toxicity monomer DMAA
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《复合材料学报》2012,29(1)
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。 相似文献
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纳米ZrO2对合成不饱和聚酯树脂的影响 总被引:4,自引:0,他引:4
用“反应法”制备纳米ZrO2/UPR.是将纳米ZrO2粉在合成不饱和聚酯时加入。用正交优选试验得到合成树脂最佳配方为:二元酸与二元醇的摩尔比是1:1,饱和酸与不饱和酸的摩尔比是1:1,纳米ZrO2含量是7%,邻苯二甲酸酐与己二酸的摩尔比是1:1,过氧化苯甲酰用量为1%。经测试.纳米ZrO2/UPR弯曲强度和冲击强度分别为121.3MPa,10.1kJ/m^2.较UPR分别提高28.4%和16.1%,得到了同时增韧增强的树脂。 相似文献
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以氧氯化锆和硝酸锰为主要原料,采用Sol—Gel—VFD技术制备了MnOx/ZrO2超细粉体材料。用XRD,TG—DSC,TEM和BET等技术对试样进行了表征,用微反应器-气相色谱仪在线研究了试样不同配合比例对试样催化还原NO的活性的影响。结果表明:用Sol—Gel—VFD技术可制得粒子尺寸约为20nm、具有高催化活性的负载型MnOx/ZrO2纳米催化剂,锰由低价向高价转变。添加了Ce组分能提高MnOx/ZrO2纳米催化剂催化还原NO的活性。 相似文献
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用纳米ZrO2(4Y)粉为原料,研究了单轴压片素坯成型特征.通过两次施压成型,降低了烧结致密温度,在1300℃常压烧结2小时,陶瓷体致密度达99.1%,烧结体晶粒长大减缓.片状烧结体1000℃和800℃时的电导率分别为4.23×10-2Ω-1cm-1和1.19×10-2Ω-1cm-1. 相似文献
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对纳米ZrO2颗粒的制备、改性、表征及其作为远红外辐射材料的应用作了介绍.对于纳米ZrO2颗粒的制备,重点介绍了化学沉淀法、溶胶-凝胶法以及微乳液法工艺,此外,简介了超声化学法、高温喷雾分解法、冷冻法等工艺;纳米ZrO2颗粒的改性,着重介绍了提高其远红外发射性能的手段;并介绍了其远红外发射性能、物相分析(XRD和UV Raman)和热分解(IES)等表征测试手段. 相似文献
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用共沉淀法制备了SO4^2-/ZrO2-SiO2固体酸催化剂,通过XRD、BET、IR、SEM等综合实验手段考察了SiO2的加入量不同对固体酸的晶体结构的影响,并以乙酸正丁酯的酯化反应为探针实验考察了SO4^2-/ZrO2-SiO2的催化性能。结果表明,SiO2的加入抑制了ZrO2晶型的转变,提高了催化剂的活性。 相似文献
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采用蜡基ZrO2粉末喂料注射成型获得大尺寸ZrO2陶瓷粉末注射产品(坯体),并根据喂料热分析曲线的变化特点,系统研究了大尺寸ZrO2坯体的热脱脂过程及规律。通过对热脱脂前后坯体的重量损失、尺寸收缩、外观缺陷和微观组织形貌的分析评估,着重探讨了大尺寸ZrO2坯体热脱脂过程中存在的主要缺陷和成因。研究表明,流蜡、鼓泡和开裂等热脱脂缺陷主要发生在低温脱脂阶段,其主要原因是液态石蜡扩散及分解过程的失衡。为此,结合“失重率控制”的思路和喂料的热失重规律,对热脱脂工艺进行了优化,在不延长总脱脂时间的前提下,显著提高了大尺寸ZrO2坯体的脱脂合格率。 相似文献
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《International journal for numerical methods in engineering》2018,113(9):1488-1506
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. 相似文献
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Standards are the basis for production enterprises to organize production ex-factory inspection trade 《中国标准化(英文版)》2008,25(1):24-25
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.…… 相似文献
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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. 相似文献
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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.…… 相似文献
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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. 相似文献
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C. Qihong W. Zhan‐Wen J. Yi J. Yehua L. Fei F. Hanguang 《Materialwissenschaft und Werkstofftechnik》2014,45(7):582-590
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. 相似文献
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《中国标准化(英文版)》2014,(4)
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 相似文献
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《中国标准化(英文版)》2014,(5)
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. 相似文献
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《中国标准化(英文版)》2014,(4)
正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to 相似文献