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1.
杨海  马勇 《功能材料》2000,31(B05):43-44
研究了类钙钛矿结构La0.67Ca0.33MnOx巨磁电阻薄膜(生长在LaAlO3衬底)的电阻变化,观察到负巨磁电阻效应,讨论了优化制备工艺提高巨磁电阻效应和最大电阻温度,其效应可用于设计新电磁器件。同时讨论了巨磁电阻效应的机理,给出合理解释。  相似文献   

2.
La0.67Ca0.33Mno3—δ体材料的巨磁电阻特性   总被引:2,自引:0,他引:2  
利用高温烧结法制备了多晶立方结构的La0.67Ca0.33MnO3-δ体材料。材料的居里温度(Tc)为280K,其金属-半导体转变温度(Tp)为270K,接近于Tc。外加磁场下的磁电阻(MR)峰值温度与Tp十分接近。外加磁场为0.6T和5T时,材料的MR峰置分别过到40%和76%,材料具有显著的巨磁电阻效应,在液氮温度附近,也观察到了相当大的磁电阻效应。  相似文献   

3.
文摘(2)     
文摘(2)l高能量废弃爆炸物的回收处理(英文)C94293152TORMASC(OlinOrdnance,FL),RISERB(NationalOrdnanceandMum-b。usEn川r。"men比ITestcen忱r,AR),TORMAAE(E...  相似文献   

4.
REPORTONELECTROMAGNETICMETROLOGYINCHINADURING1990-1992¥YangXiaoren;RenDianqing;LiZizhong(CommissionA,CommitteeforChineseURSI)...  相似文献   

5.
采用磁控溅射方法在ZrO2(001)、Si(001)和玻璃衬底上成功地制备了LaCaMnO(以下简称为LCMO)巨磁电阻薄膜。X-射线分析表明,ZrO2的晶格常数与LCMO的晶格常数失配虽然较大,仍可得到较好的LCMO薄膜。在Si片上难以制备出致密完整的LCMO薄膜,其原因有待查明。玻璃衬底上可以获得纯相的LCMO巨磁电阻薄膜,在ZrO2衬底上制备的LCMO薄膜,其巨磁电阻效应在150K,3000Gaus下达13%左右。  相似文献   

6.
橡胶增韧AS树脂研究   总被引:2,自引:0,他引:2  
用NBR、EVA、MBS和CPE单独或联合增韧AS树脂,研究表明,MBS/NBR和MBS/CPE对AS树脂有协同增韧效应,EVA可作为AS/NBR体系的相容剂,NBR中AN含量将影响增韧效果,并用TEM和SEM观察了共混物的形态。  相似文献   

7.
锰氧化物的巨磁电阻效应的探索   总被引:5,自引:0,他引:5  
高瑞平 《材料导报》1999,13(1):29-31
概述了锰氧化物的巨磁电阻效应的研究进展,讨论了锰氧化物的结构特点,电磁特性以及可能的导电机理。在La1-xAxMnO3中,当阳离子La被二价的A离子部分替代时,部分Mn^2+转变为Mn4+离子,形成Mn^2+/Mn^4+混合价态,改善了材料的电导,并由此而产生了CMR效应。  相似文献   

8.
采用磁控溅射方法制备了NiFe/Cu和NiFe/Mo两个系列的多层膜,进行了结构,磁性和磁电阻测量,并对部分NiFe/Cu多层膜样品作了电镜分析,对于NiFe/Cu多层膜,在室温下的测量到巨磁电阻随Cu层厚度振荡的第一,二三峰。在NiFe/Mo多层膜样品中未发现巨磁电阻效应,讨论了非磁性 多层膜的磁性,界面结构和巨磁电阻效应。  相似文献   

9.
利用固相反应法制备了多晶立方结构的La-Pb-Mn-O体材料,材料的铁磁相变温度TC为257K,其金属-半导体转变温度TP为251K,外加磁场分别为5T和13T时,材料的巨磁电阻(GMR)峰值分别达到了72%和85%,在77K ̄室温的温度范围内,材料都具有GMR效应,TP附近具有GMR峰值效应,GMR效应与自旋极化行为有关,而TP附近的GMR峰值效应除了与自旋极化子行为有关外,与磁场作用下勒流子自  相似文献   

10.
CORBA在TMN环境中的应用   总被引:4,自引:0,他引:4  
在分析了电信管理网(TMN)和公共对象请求代理体系结构(CORBA)各自特点的基础上,探讨了CORBA在TMN中的应用,并提出一种新的基于CORBA的TMN管理平台构想。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
正The Chinese Premier Li Keqiang's recent trip to the UK has reinforced the China-UK comprehensive strategic partnership;just as the British Prime Minister David Cameron put it,"the relationship is gaining in strength,depth and understanding"after a bucket of business deals being inked worth more than 30 billion US dollars.From the first agreement signing in 2004 to the new agreement of mutual standards recognition and adoption in  相似文献   

17.
正A national directory of standards complexes for strategic emerging sectors was recently developed and released jointly by 12governmental departments,namely,SAC,NDRC,MOST,MIIT,MEP,MOA,AQSIQ,State Forest Administration,State Administration of Science and Technology for National Defense,State Oceanic Administration and National Railway Administration.  相似文献   

18.
正Four new national standards on air pollutant emission control offi cially issued by the Ministry of Environment Protection(MEP)together with AQSIQ and SAC has been brought into force from July 1,2014.The Emission standard for air pollutants of coal-burning,oil-burning and gasfi red boilers,which is the strictest emission standard historically,will tackle the stubborn pollution problem of boilers and waste incineration in most of China’s regions.  相似文献   

19.
《新型炭材料》2014,(6):460
New Carbon Materials is a bimonthly journal published with the permission of the Ministry of Science and Technology and of the State News and Publication Agency.The journal is sponsored by the Institute of Coal Chemistry,Chinese Academy of Sciences,and is published by Science Press.Aims and Scope  相似文献   

20.
正Recently,National Copyright Administration of China(NCAC)has rewarded 215 organizations and 179 individuals for their outstanding efforts on investigating standards copyright infringement and piracy in 2013.Hua Jianhua,the Deputy-Director of National Standards Copyright Protection Workgroup Office won a third prize of the national individual award.In 2012,SAC set up the national standards copyright protection working group,and developed policies to crack down standards infringement and piracy behaviors and to strengthen standards copyright protection.  相似文献   

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