Investigations regarding the behaviour of historic glass and its surface layers towards different wavelengths applied for laser cleaning     

Farideh Fekrsanati  Stefan Klein  Jens Hildenhagen  Klaus Dickmann  Yiorgos Marakis  Aleka Manousaki  Vassilis Zafiropulos   《Journal of Cultural Heritage》2001,2(4):187

The application of lasers for the removal of superficial deposits from historic stained glass is a comparatively new field of scientific interest. Experimental studies concerning the behaviour of glass substrates and the corresponding superficial deposits towards different laser wavelengths were carried out. The experiments were performed using wavelengths of λ = 193 nm (ArF-Excimer), 308 nm (XeCl-Excimer), 355 nm (Nd:YAG third harmonic) and 1 064 nm (Nd:YAG fundamental) in comparison to λ = 248 nm (KrF-Excimer). This comparison is due to the fact that the present knowledge is based on the 248 nm wavelength. Specially prepared model glass samples representing the original fragments and samples of organic polymers (formerly used as a protective material for historic stained glasses) were used to study the effects of laser radiation and were subsequently characterised by optical microscopy.  相似文献   

不同负荷运动训练对大鼠红细胞膜的影响   总被引：2，自引：0，他引：2  

郑兵  赵歌  王震 《广州体育学院学报》2004,24(6):45-47

通过本实验研究得出以下结论力竭运动后L组RBCMNa+-K+ATP酶活性增加,提示适宜负荷的运动训练不但可提高安静时酶活性,且可增强其活性的储备力.H组酶活性受其膜组成及物理特性改变的影响而下降,反过来又影响膜特性及功能,提示大负荷训练造成的膜理化性生质的改变是相互关联的.运动训练对Ca2+-ATP酶活性无明显影响,H组活性的下降与其RBCM上脂质组成及其膜流动性的变化有关.  相似文献   

Google Scholar and Web of Science: Examining gender differences in citation coverage across five scientific disciplines     

Jens Peter Andersen  Mathias Wullum Nielsen 《Journal of Informetrics》2018,12(3):950-959

Many studies demonstrate differences in the coverage of citing publications in Google Scholar (GS) and Web of Science (WoS). Here, we examine to what extent citation data from the two databases reflect the scholarly impact of women and men differently. Our conjecture is that WoS carries an indirect gender bias in its selection criteria for citation sources that GS avoids due to criteria that are more inclusive. Using a sample of 1250 U.S. researchers in Sociology, Political Science, Economics, Cardiology and Chemistry, we examine gender differences in the average citation coverage of the two databases. We also calculate database-specific h-indices for all authors in the sample. In repeated simulations of hiring scenarios, we use these indices to examine whether women's appointment rates increase if hiring decisions rely on data from GS in lieu of WoS. We find no systematic gender differences in the citation coverage of the two databases. Further, our results indicate marginal to non-existing effects of database selection on women's success-rates in the simulations. In line with the existing literature, we find the citation coverage in WoS to be largest in Cardiology and Chemistry and smallest in Political Science and Sociology. The concordance between author-based h-indices measured by GS and WoS is largest for Chemistry followed by Cardiology, Political Science, Sociology and Economics.  相似文献   

Organismic integration as a dynamic process: a systematic review of empirical studies on change in behavioral regulations in exercise in adults     

Anna Wasserkampf  Jens Kleinert 《International review of sport and exercise psychology》2016,9(1):65-95

In facilitating the adoption of exercise behavior, attention should be directed towards the dynamic nature of behavioral regulations. Organismic integration theory presents a suitable framework for investigating fluctuations in behavioral regulations. However, current results pertaining to this issue revealed mixed findings. The aim of this review is to examine the empirical literature on the dynamic nature of organismic integration theory in exercise settings over time in adults. A systematic review of English articles using PsycINFO, PsycARTICLES, ScienceDirect, and SPORTDiscus was conducted including keywords of organismic integration theory, longitudinal designs, change in behavioral regulations, and exercise. Findings are summarized through quantitative analysis of the evidence. Regarding autonomous regulations, steady increases in regulations are observable that originate within the first weeks and persist for up to one year. Most studies reported no changes in controlled regulations, although in a few cases changes were observed six weeks after baseline or later. The review adds to the theoretical understanding of how behavioral regulations are internalized. However, whether changes in regulation occur depends on both the type of regulation and on contextual characteristics. Future research of longitudinal design is warranted to identify optimal periods in which individuals seek for increased support during exercise adoption.  相似文献   

试析《学记》中的主体教学观     

王全乐  申卫革 《保定师专学报》2002,15(3):82-83

《学记》是我国两千多年前第一部系统论述教育问题的专著,被称为“教育学的雏形”,许多教育思想历久弥新,特别是其中的主体教学思想对我们当今的教育教学改革仍有较强的指导和借鉴意义。  相似文献   

Spannungsfeld Polyvalenz in der Lehrerbildung     

Dr. Johannes Bauer  Dr. Uta Diercks  Prof. Dr. Jan Retelsdorf  Dr. Tabea Kauper  Dr. Friederike Zimmermann  Prof. Dr. Olaf K?ller  Dr. Jens M?ller  Prof. Dr. Manfred Prenzel 《Zeitschrift für Erziehungswissenschaft》2011,14(4):629-649

The Bologna Process of higher education reform has led to a vast array of different programs of study in German teacher training. In this article, we firstly analyze the implementation of Bachelor programs in teacher training, comparing profession-oriented programs (i.e. those aiming to train students for the teaching profession from the beginning of studies) to polyvalent programs (i.e. those aiming at broad qualifications and including a late decision to become a teacher). Secondly, we investigate whether students enrolled in these study programs differ systematically in their subjective certainty about their career choice. To answer these questions, we analyze portfolios of documents related to teacher training programs from nine German universities that prepare students for teaching in the academic track. Additionally, we analyze data from N?=?2585 Bachelor and N?=?928 Master degree students. We found that most programs, even when they espouse polyvalence, require an early decision to become a teacher. Moreover, our data confirm findings from earlier studies indicating that student teachers are highly certain about their career choice from the very beginning, with students in polyvalent programs being slightly less certain than those in profession-oriented programs (d?=?0.32).  相似文献   

中小学教师职业道德失范行为透析及控制对策   总被引：3，自引：0，他引：3  

杨金国  薛艳格 《保定师专学报》2005,18(1):49-51

经过调查研究，概括了中小学教师职业道德在热爱学生、尊重家长、依法执教、廉洁从教等方面失范行为的突出表现，讨论了中小学教师职业道德失范行为的主观原因和社会原因，提出了控制中小学教师职业道德失范的对策。  相似文献   

基于工作流的产品制造流程系统体系研究     

徐巧格 《科技．人才．市场》2007,28(6):88-90

工作流管理系统为制造企业的产品制造流程系统应用提供理论基础和技术支撑。本文提出了面向制造企业的，产品制造流程模型和基于工作流技术的产品制造流程系统体系，通过该系统体系可以实现产品制造流程的自动化执行。  相似文献   

Investigating the relationship between pre-service physics teachers' professional knowledge,self-concept,and interest     

Stefan Sorge  Melanie M. Keller  Knut Neumann  Jens Möller 《科学教学研究杂志》2019,56(7):937-955

This study investigates the relationships between professional knowledge, self-concept, and interest of pre-service physics teachers. In order to support student learning and interest development alike, teachers need a profound professional knowledge and respective motivational orientations. Developing both professional knowledge and motivational orientations in teachers is therefore a key challenge of teacher education. Prior research has focused on the development of content knowledge (CK) and pedagogical content knowledge (PCK) within teacher education, but the role of motivational orientations such as self-concept and interest have mostly been neglected areas of study. As individuals develop domain-specific motivational orientations, they compare their achievement in an external frame to the achievement of their peers, and they compare their achievements in an internal frame across domains. The effects of these psychological processes on domain-specific motivational orientations are described by the generalized internal/external frame of reference model (GI/E model). We assessed the professional knowledge (CK and PCK) and motivational orientations (self-concept and interest) of N = 200 pre-service physics teachers from 12 teacher education institutes in Germany. To investigate the predictions of the GI/E model, we utilized structural equation modeling. In line with the GI/E model, the analysis revealed that pre-service teachers use social comparisons. Pre-service teachers with a higher CK/PCK also showed a higher CK/PCK self-concept. We also identified instances of internal comparisons as we found that a high level of CK corresponds with a lower PCK self-concept. While we could not identify the same effects from professional knowledge on interest, self-concept mediated the effects from professional knowledge on interest. The results suggest that interdependencies between professional knowledge and motivational orientation should be given more consideration in teacher education research and should also be addressed more explicitly in teacher education.  相似文献   

立法建制 加强体育院校教师队伍的建设     

赵勇戈 《体育成人教育学刊》2002,18(2):8-10

在制度和机制创新方面需要采取 5种措施 :即建立依法管理的制度 ,形成校方与教师之间的互动约束力 ;建立竞赛聘任机制 ,增强教师队伍建设的活力 ;建立激励优秀拔尖人才脱颖而出的分配机制 ,形成发挥自身潜能的动力 ;构建教师继续教育制度 ,形成一种提升力 ;建立师德教育和奖励制度 ,形成一种凝聚力  相似文献