首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   58篇
  免费   3篇
教育   33篇
科学研究   15篇
各国文化   1篇
体育   5篇
文化理论   2篇
信息传播   5篇
  2022年   1篇
  2021年   2篇
  2020年   4篇
  2019年   5篇
  2018年   2篇
  2017年   6篇
  2016年   4篇
  2015年   3篇
  2014年   3篇
  2013年   11篇
  2012年   3篇
  2011年   5篇
  2010年   2篇
  2008年   2篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2004年   3篇
  2003年   1篇
  2002年   1篇
排序方式: 共有61条查询结果,搜索用时 15 毫秒
51.
ABSTRACT

The surface texture of a stone represents a sensitive parameter in evaluating its conservation state. In monuments and sculptures, in fact, external agents continuously alter the appearance of stones, determining peculiar weathering patterns and modifying properties such as retention of water and particles, interaction with light, color, and finishing. The application of protective coatings also determines changes in surface appearance of a stone, usually evaluated and monitored by color change tests. Surface metrology methods offer the possibility to quantify these changes, evaluating the impact of external agents (natural, i.e. weathering, and artificially, i.e. protective coatings) on natural stones. In this research, we demonstrate the potential of surface areal measurements in describing the evolution of weathering processes and the effects of protective treatments on porous stone materials. The obtained results suggest that the extent of the modifications is related to the scale of observation (small- vs. large-scale undulations, i.e. roughness and waviness, respectively), with an overall increase of surface roughness as the weathering proceeds. Unexpectedly, coatings based on nanoparticle dispersions increase the topographic height parameters, due to the absence of a homogeneous film.  相似文献   
52.
53.
54.
This chapter explores the processes of privatisation of higher education in Chile (after 1981) and Romania (after 1989), focusing on the emergence of private institutions, the expansion in enrolments in these institutions, and the relative increase in private sources of funding for the post‐secondary sub‐sector. Attention is also given to related trends in higher education in these two countries: domestic marketisation (a strengthening of an orientation toward selling programmes/commodities to students/consumers within the country) and international commercialisation (an expansion of initiatives by domestic and foreign institutions to provide distance education, study abroad/exchange, and foreign site‐based degree programmes). Of importance to an understanding of globalisation, these two societies, which at the time exhibited similar economic systems but had different political systems and were situated in different regional contexts, experienced remarkably similar processes of and outcomes from privatisation, marketisation, and commercialisation. In both cases these processes were promoted by ‘internal’ political actors but also shaped by ‘external’ forces, notably the World Bank's higher education policy recommendations and the conditionalities included in the stabilisation and structural adjustment programmes ‘negotiated’, respectively, with the International Monetary Fund and the World Bank in order to obtain loans. As a result of these processes—occurring prior to and during the emergence of the General Agreement on Trade in Services (GATS) as a component of the World Trade Organization (WTO)—higher education institutions in both Chile and Romania are much more vulnerable to foreign influence/domination, although they also have somewhat greater opportunities to broaden their role in the global ‘business’ of higher education.  相似文献   
55.
Two experiments examined the development of recollection (recalling qualitative details about an event) and familiarity (recognizing the event) using the dual-process signal detection model. In Experiment 1 (n = 117; ages 6, 8, 10, 14, and 18 years), recollection improved from childhood to adolescence after semantic encoding but not after perceptual encoding and familiarity improved from ages 6 to 8 regardless of encoding condition. In Experiment 2 (n = 56; ages 6, 8, and 10 years), long duration compared to short duration of semantic encoding increased familiarity but not recollection. Age-related differences replicated those of Experiment 1, except no age difference in familiarity was found with long study duration. Overall, recollection and familiarity showed distinct developmental and functional characteristics. The dual-process signal detection model proved promising for developmental investigations.  相似文献   
56.
The purpose of the current study was to examine, within an integrative predictive model, the relative contributions of sociodemographic variables, personal resources, and work wellbeing to teacher burnout. The research was conducted with special education teachers at Italian preschools—a context in which few previous studies have been carried out—and primary schools. A cross‐sectional survey‐based study with a sample of 194 kindergarten and primary school teachers was conducted. The results indicated that teachers’ happiness at school and job satisfaction incrementally predicted variance in personal, work‐related, and student‐related burnout, even after controlling for the effects of sociodemographic factors and personal resources. Furthermore, the final integrative predictive model was similar for both kindergarten and primary teachers.  相似文献   
57.

Background

Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is a rare inherited mitochondrial fatty acid oxidation disorder associated with variations in the ACADS (Acyl-CoA dehydrogenase, C-2 to C-3 short chain) gene. SCADD has highly variable biochemical, genetic and clinical characteristics. Phenotypes vary from fatal metabolic decompensation to asymptomatic individuals.

Subject and methods

A Romani boy presented at 3 days after birth with hypoglycaemia, hypotonia and respiratory pauses with brief generalized seizures. Afterwards the failure to thrive and developmental delay were present. Organic acids analysis with gas chromatography-mass spectrometry (GS/MS) in urine and acylcarnitines analysis with liquid chromatography-tandem mass spectrometry (LC-MS/MS) in dried blood spot were measured. Deoxyribonucleic acid (DNA) was isolated from blood and polymerase chain reactions (PCRs) were performed for all exons. Sequence analysis of all exons and flanking intron sequences of ACADS gene was performed.

Results

Organic acids analysis revealed increased concentration of ethylmalonic acid. Acylcarnitines analysis showed increase of butyrylcarnitine, C4-carnitine. C4-carnitine was 3.5 times above the reference range (<0.68 µmol/L). Confirmation analysis for organic acids and acylcarnitine profile was performed on the second independent sample and showed the same pattern of increased metabolites. Sequence analysis revealed 3-bp deletion at position 310-312 in homozygous state (c.310_312delGAG). Mutation was previously described as pathogenic in heterozygous state, while it is in homozygous state in our patient.

Conclusions

In our case clinical features of a patient, biochemical parameters and genetic data were consistent and showed definitely SCAD deficiency.Key words: SCAD deficiency, short chain acyl-CoA dehydrogenase deficiency, screening, acylcarnitine, polymorphism, genetic  相似文献   
58.
The sculptural polychromy in the Zhongshan Grottoes, sited in northwest China, has been investigated in terms of chemical composition of employed materials and pigments, state of conservation and painting technique. Raman analysis, Fourier-transform infrared analysis, analysis through energy-dispersive X-ray spectrometry coupled to scanning electron microscopy and pyrolysis coupled to gas chromatography and mass spectrometry were applied. Six analyzed samples showed silicates and kaolin as main components of the ground layers. Also lead white has been found in these layers. Minium, red-earth and mercury sulfide are the red pigments detected in the polychromy. A mixed use of malachite and atacamite has been detected in three green samples. Optical characteristics of atacamite and malachite found in the samples indicate a synthetic origin. The presence of a synthetic organic pigment such as phthalocyanine chlorinated pigment was also revealed. Ultramarine blue pigment, obtained by purification of lapis lazuli, has been detected in the blue sample. As for the binders used, fatty materials and siccative oil were found.  相似文献   
59.
While the Los Angeles Olympic Games in 1984 constituted Romania's best performance ever, 2012 London Olympic Games were characterised by the worst performance in its history. During the time between these two events, the country went from being a communist regime to a liberal government. This transition invites consideration of the transformation Romania's sports policy underwent and its repositioning with regard to the Olympic Movement, both before and after the 1989 turning point. Analysis suggests that, in failing to professionalise Romanian sport, the Romanian Olympic and Sports Committee (COSR) was tempted to readopt a model of state-financed sport, with the aim of reinstating the nation to its former position among the world's sporting elite.  相似文献   
60.
Purpose: This study explores the potential of the Farm Accountancy Data Network (FADN) to assess the technical, economic and environmental effects of cooperative innovation projects at farm level.

Design/Methodology/Approach: The analysis of the FADN potential relies on the classification of innovations and the co-identification, through the Most Significant Change (MSC) approach, of the most relevant indicators for tracking and assessing the performances of innovations and attributing to them the effects of a specific innovation.

Findings: The study shows that the FADN has a certain range of useful indicators and that they have a good coverage of the different types of innovation. Furthermore, the farm visits let emerge the importance of participatory approaches to capture the different changes and interplays occurred in farming processes.

Practical implications: The paper lays the foundations for the adaptation of the current methodology for data collecting and provides useful insights concerning the overcoming representativeness claims, costs’ issues, and problems related to the observation time limit.

Theoretical implications: The paper reveals the importance of participatory monitoring and evaluation approaches in helping the collection of more robust and relevant account data on farm, as well as in attributing certain results to a specific innovation and recognising synergies and side-effects of cooperative processes.

Originality/Values: The paper provides some recommendations on how to enlarge the scope of the FADN survey in order to be used effectively in the analysis of the performance of cooperative innovations at farm level.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号