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991.
Chemically processed Nb-doped SrTiO3 films and properties 总被引:1,自引:0,他引:1
Ming-zhi Yin 《浙江大学学报(A卷英文版)》2006,7(8):1436-1439
Homogeneous, crack-free SrNbxTi1−x
O3 thin films on (110) silicon substrates were successfully fabricated by sol-gel processing. The optimum route and conditions
were systematically investigated. Sr(OAc)2 glacial acctic acid solution, after being refluxed and reacted with tartrate, formed Sr(OAc)2(C4H6O6)2; Ti(OBu)4 formed Ti(OAc)4−x
(AcAc)x after having the ligand partially exchanged with AcAc, while Nb(OC2H5)5 formed (OAc)2Nb(AcAc) (C4H6O6) by exchanging of ligand in glacial acetic acid with (CH3CO)2O. All the metal species after undergoing partial hydrolysis and polymerization with hydroxyl or oxygen, formed SrNbxTi1−x
O13 cluster sol. Methyl cellulose (MCL) caused SrNbxTi1−x
O3 sol to have polymeric structure and easily form films. SrNbxTi1−x
O3 films with perovskite were subsequently formed after being annealed at 650∼750 °C for 60 min in 25% N2+75% H2 (volume ratio) atmosphere. Resistivity of the SrNb0.1Ti0.9O3 films at room temperature was 64 μω·cm, a particular T
2 temperature dependence of the resistivity, from 25 K up to room temperature, was observed.
Project (No. 2002CB613305) supported by the National Basic Research Program (973) of China 相似文献
992.
Fordham and Ogbu (1986) have described fear of acting white as a significant factor that influenced the attitudes and often undermined the achievement of African-American students at Capital High in Washington, D.C. The present qualitative study investigated 38 relatively high-achieving African-American and Mexican-American students in various high schools, public and private, in a midwestern city. The respondents did not report avoiding academic achievement in order to avoid accusations of acting white. Most of the students we interviewed reported no loss of ethnic identity. The students felt strong resentment toward their peers' accusations of acting white and did not seem to be intimidated by the accusations, though they were bothered by the accusations. It would be useful if future research addressed the conditions under which avoidance of acting white is most likely to occur. 相似文献
993.
Dana G. Holland 《Higher Education》2008,55(6):671-681
Changes in research production precipitated by the globalization have generally been theorized as applying across nations
and disciplinary projects. This article examines the relation of discipline to research production from the situational vantage
point of the developing world, specifically the Southern African country of Malawi, and from the empirical perspective of
the social sciences. Evidence derives from eight months of ethnographic fieldwork conducted in Malawi in 2003 and 2004, drawing
specifically from over 100 formal interviews and from analysis of historical and contemporary documents. The article finds
that against depictions of academic disciplines as inflexible, arbitrary, and in need of restructuring, the case of the social
sciences in Malawi demonstrates the value of distinctly disciplined expertise in problem-oriented research. This efficacy
is, however, precariously dependent on the capacity of local disciplinary communities to regenerate and reproduce their expertise
and compete effectively in the increasingly competitive knowledge market.
相似文献
Dana G. HollandEmail: |
994.
“3 1”模式计算机专业实践教学的一些探索 总被引:1,自引:0,他引:1
实践教学是高等教育的重要组成部分,是培养学生创新精神和实践能力的重要教学环节,结合上海大学"3 1"模式教学改革实践,为应对计算机技术的高速发展和学生毕业设计阶段遇到的新问题及学生毕业面临的就业新形势,文章介绍了该校计算机专业使"大三"短学期实践教学成为学生毕业设计和学生走向实际工作岗位预演的一些尝试和体会。 相似文献
995.
Li?Yong-quanEmail author Cen?Pei-lin Chen?Shi-fei Wu?Dan Zheng?Jing 《浙江大学学报(A卷英文版)》2004,5(2):173-179
Two-component genes are kinds of genetic elements involved in regulation of antibiotic production inStreptomyces coelicolor. DNA microarray analysis revealed thatecrA1/A2, which mapped at distant sites fromred lucus and encode respectively the kinase and regulator, expressed coordinately with genes of Red specific biosynthetic pathway.ecrA1 andecrA2 gene-disruptive mutants were constructed using homogenotisation by reciprocal double crossover. Fermentation data showed
that the undecylprodigiosin (Red) level of production was lower than that of wild-type strain. However, the change of the
actinorhodin (Act) production level was not significant compared with wild type. Thus, these experiment results confirmed
that the two-component systemecrA1/A2 was positive regulatory element forred gene cluster.
Project (No.20172046) supported by the National Natural Foundation of China 相似文献
996.
LIN Jia-mu LIU Dan 《重庆大学学报(英文版)》2006,5(4):229-234
1 Introduction a Grey theory, originally developed by Deng [1], is a truly multidisciplinary and generic theory that deals with systems of deficient information. In the field of information research, light and deep colors respectively represent informatio… 相似文献
997.
二语习得过程中的母语思维现象 总被引:2,自引:0,他引:2
彭宁红 《湖南师范大学教育科学学报》2004,3(3):115-117
母语思维在二语习得过程中是客观存在的,它对二语习得会产生正面的和负面的影响,即正迁移和负迁移。我们应该引导学生利用语言的共性来促进“正迁移”,借助母语思维来促进二语习得,进而提高目的语学习的效率。 相似文献
998.
Elke Standeker Georg Streit Maren Pressinger-Buchsbaum 《Zeitschrift für Hochschulrecht, Hochschulmanagement und Hochschulpolitik: zfhr》2008,7(1):21-28
Mit dem Urteil zu 1 Ob 142/07z best?tigte der OGH die Entscheidungen der Vorinstanzen, wonach die Klage eines Studierenden
gegen eine Universit?t auf Feststellung, dass die beklagte Partei der klagenden Partei für s?mtliche aus der Unterlassung
des Anbots von Parallellehrveranstaltungen zukünftig entstehenden Sch?den hafte, wegen fehlender Passivlegitimation abgewiesen
wurde. Das H?chstgericht stellte eindeutig klar, dass "Universit?ten in Vollziehung der Studienvorschriften im Rahmen der
Hoheitsverwaltung t?tig werden", weshalb ein zivilrechtlicher Anspruch gegen die Universit?t aufgrund eines zu geringen Angebots
von Lehrveranstaltungen nicht in Betracht kommt und bekr?ftigte, dass die Haftung der Universit?t oder ihrer Organe für hoheitliches
Handeln in Vollziehung der Studienvorschriften auch nach dem UG 2002 ausgeschlossen ist. 相似文献
999.
用荧光光谱研究了1,4-二氢吡啶衍生物(1,4-DHP)与小牛胸腺DNA(CT-DNA)的相互作用。结果表明,1,4-DHP衍生物分子与CT-DNA相互作用后,如其荧光显著增强,表明1,4-DHP衍生物分子嵌入到CT-DNA中,如荧光明显减弱,表明1,4-DHP衍生物分子不是以嵌入模式与CT-DNA相互作用。 相似文献
1000.
本文研究了1.5—环辛二烯在AlCl_3或AlCl_3与和C_2H_5B_1催化下的聚合反应,并探讨了该反应的机理。 相似文献