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1.
纳米(ZnO,Al2O3)复合掺杂对3Y2O3-ZrO2材料电性能的影响   总被引:1,自引:0,他引:1  
以3Y2O3—ZrO2纳米粉和ZnO,A12O3纳米粉为原料,采用交流阻抗谱技术对掺少量ZnO和A12O3的3Y2O3—ZrO2烧结陶瓷进行电性能研究。研究表明:少量纳米ZnO掺杂降低了3Y2O3—ZrO2的电导率,但随着掺人量的增加,电导率开始回升。在ZnO掺杂样品中加入少量纳米A12O3进行复合第二相掺杂,结果提高了3Y2O3—ZrO2材料的电导率。同时少量A12O3的掺人降低了晶粒电导活化能,使得晶粒电导率增加。  相似文献   

2.
纳米ZnO对纳米ZrO2(8Y)致密特性及电导率影响研究   总被引:1,自引:0,他引:1  
采用纳米ZrO2(8Y)粉和纳米ZnO粉为原料,对掺少量ZnO的ZrO2(8Y)进行无压烧结研究.实验结果表明,掺少量的ZnO能促进ZrO2与Y2O3的反应,加快四方相向立方相的转变,样品致密度和电导率显著提高.掺0.5wt%ZnO样品在1200℃煅烧2h的陶瓷致密度为94%,700℃时的电导率为9.02×10-3cm-1·Ω-1.  相似文献   

3.
掺入Al2O3对固体氧化物电解质材料YSZ性能影响的研究   总被引:1,自引:0,他引:1  
《功能材料》2000,31(Z1):53-54
在立方相的钇稳定化氧化锆[(ZrO2)0.92(Y2O3)0.08](YSZ)中,掺入少许不同量的Al2O2,研究其对基体材料YSZ的烧结性能、机械强度和导电性能的影响,并对其机理进行了分析。实验结果表明,掺入Al2O2能够明显降低电解质烧结温度,改善烧结性能。在1300℃烧结1h后,少量掺杂Al2O3的样品晶粒尺寸明显比纯YSZ样品的小;从阻抗谱图上可以看出,随着Al2O3含量的zk加,晶界电阻不断减小,在掺杂比例为4%(质量分数)时,达到最小点。而后随着Al2O3含量的zk加,晶界电阻又呈上升趋势。用纯YSZ和掺4%(质量分数)Al2O的材料制成SOFC,得到伏安特性曲线,结果表明,掺4%(质量分数)Al2O3的性能比YSZ好。  相似文献   

4.
纳米ZnO掺杂对ZrO2(8mol% Y2O3稳定)电性能的影响研究   总被引:1,自引:0,他引:1  
采用纳米粉料,在单轴成型,无压烧结条件下,用交流阻抗谱技术对掺不同质量百分比ZnO的ZrO2(8mol% Y2O3稳定)烧结体的电性能进行了研究.研究发现ZnO掺杂对ZrO2(8mol% Y2O3稳定)的离子导电性能具有优化作用.  相似文献   

5.
在立方相的钇稳定化氧化锆 [(ZrO2 ) 0 .92 (Y2 O3) 0 .0 8](YSZ)中 ,掺入少许不同量的Al2 O3,研究其对基体材料YSZ的烧结性能、机械强度和导电性能的影响 ,并对其机理进行了分析。实验结果表明 ,掺入Al2 O3能够明显降低电解质烧结温度 ,改善烧结性能。在 130 0℃烧结 1h后 ,少量掺杂Al2 O3的样品晶粒尺寸明显比纯YSZ样品的小 ;从阻抗谱图上可以看出 ,随着Al2 O3含量的增加 ,晶界电阻不断减小 ,在掺杂比例为 4 % (质量分数 )时 ,达到最小点。而后随着Al2 O3含量的增加 ,晶界电阻又呈上升趋势。用纯YSZ和掺 4 % (质量分数 )Al2 O3的材料制成SOFC ,得到伏安特性曲线 ,结果表明 ,掺 4 % (质量分数 )Al2 O3的性能比YSZ好。  相似文献   

6.
Y2O3掺杂BaTiO3陶瓷的介电特性   总被引:3,自引:0,他引:3  
讨论了掺杂Y2O3的BaTiO3陶瓷的介电特性,并计算了晶粒电阻、晶界电阻、晶界宽度和晶界势垒高度,也讨论了在掺Y2O3材料中加入少量Li2CO3对材料微观结构与宏观性能的影响。  相似文献   

7.
采用溶胶-凝胶法合成了Li0.5La0.5TiO3(LLTO)粉体,加入不同量的LiCl与LLT0粉体进行了复合,通过XRD,SEM等测试手段研究了复合材料的成分以及形貌,通过阻抗谱对复合材料的电导性能进行了研究。结果表明:LiCl的加入,稍降低了晶粒电导,但却明显影响了颗粒的晶界电导,使得总电导增大。LiCl的加入是通过改善晶界烧结,从而使总电导得到提高。LiCl体积含量为13%时,效果最好,总电导和晶界电导提高数倍左右。  相似文献   

8.
采用反应射频磁控溅射技术,在非晶石英衬底上不同温度下制备了纳米多晶Gd掺杂CeO2(简称GDC)氧离子导体电解质薄膜,采用X射线衍射仪、原子力显微镜对薄膜物相、晶粒大小、生长形貌进行了表征,利用交流阻抗谱仪测试了GDC薄膜的电学性能.结果表明,GDC薄膜生长取向随沉积温度而变化:300-400℃时为强(111)织构生长,而500-600℃时薄膜趋于无规则生长;随着沉积温度的升高,薄膜的牛长形貌由同一取向的大棱形生长岛转变为密集球形小生长岛;GDC多晶薄膜的电导活化能约为1.3eV,接近于晶界电导活化能值,说明GDC交流阻抗主要源于晶界的贡献;晶界空间电荷效应导致GDC薄膜电导率随晶粒尺寸而变化,晶粒尺寸越小,电导率越大.  相似文献   

9.
王飞  徐可为 《纳米科技》2004,1(6):49-52
用高真空磁控溅射在Si片上沉积纳米晶Cu膜和非纳米晶Cu膜,通过纳米压入实验得到薄膜硬度。发现晶粒尺寸对薄膜材料的压痕尺寸效应有比较大的影响,同时随加载载荷的升高,纳米晶薄膜硬度的变化与非纳米晶薄膜有很大的不同。分析认为这是因为晶粒尺寸达到纳米尺度后,晶界体积大大增加,使得晶界变形,晶界运动和晶界对位错运动的阻碍等作用影响材料塑性变形和加工硬化能力造成的。  相似文献   

10.
纳米ZnO对纳米ZrO2(8Y)致密特性及电导率影响研究   总被引:2,自引:0,他引:2  
采用纳米ZrO2(8Y)粉和纳米ZnO粉为原料,对掺少量ZnO的ZrO2(8Y)进行无压烧结研究.实验结果表明,掺少量的ZnO能促进ZrO2与Y2O3的反应,加快四方相向立方相的转变,样品致密度和电导率显著提高.掺0.5wt%ZnO样品在1200℃煅烧2h的陶瓷致密度为94%,700℃时的电导率为9.02×10-3cm-1·Ω-1.  相似文献   

11.
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   

12.
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   

13.
14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
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   

20.
新闻(英文)     
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   

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