全文获取类型
收费全文 | 669篇 |
免费 | 7篇 |
专业分类
教育 | 441篇 |
科学研究 | 51篇 |
各国文化 | 13篇 |
体育 | 83篇 |
文化理论 | 3篇 |
信息传播 | 85篇 |
出版年
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 16篇 |
2020年 | 17篇 |
2019年 | 32篇 |
2018年 | 33篇 |
2017年 | 47篇 |
2016年 | 46篇 |
2015年 | 15篇 |
2014年 | 25篇 |
2013年 | 156篇 |
2012年 | 31篇 |
2011年 | 26篇 |
2010年 | 20篇 |
2009年 | 24篇 |
2008年 | 16篇 |
2007年 | 15篇 |
2006年 | 8篇 |
2005年 | 10篇 |
2004年 | 8篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 6篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1973年 | 2篇 |
1940年 | 2篇 |
1928年 | 2篇 |
1923年 | 3篇 |
1919年 | 2篇 |
1866年 | 1篇 |
1840年 | 1篇 |
1838年 | 1篇 |
排序方式: 共有676条查询结果,搜索用时 162 毫秒
51.
Prema Clarke 《Prospects》2011,41(4):479-490
This viewpoint examines girls’ performance in primary education in the countries that joined the Education for All Fast Track
Initiative between 2002 and 2008. At the time they joined the initiative, a first group of countries (high performers) had
already achieved high and equal enrollment of girls and boys. Significant progress is evident in a second group of countries
(good performers) after joining the initiative. In contrast, a third group of countries (weak performers) continue to struggle
to achieve any increase in girls’ enrollment. The article summarizes the various interventions that countries have adopted
to encourage girls to attend school and then highlights the importance of developing strategic plans based on extensive collaboration
between development partners and government. The viewpoint concludes by describing the three challenges that remain: increasing
learning, reducing the number of out-of-school girls, and improving girls’ performance in fragile and post-conflict countries. 相似文献
52.
产业集群对区域乃至国家经济发展具有重要的作用,然而产业集群发展过程中的影响因素及其相互作用机制至今仍未得到系统的阐述.从协同演进理论视角,结合组织生态学、制度理论、战略管理理论和社会网络理论等,对天津自行车产业集群的发展历程展开多层次、时间序列的分析,以深入挖掘产业集群发展过程中各种要素的相互作用、协同演进机制,提出产业集群的发展是企业战略、产业环境以及制度环境协同演进的过程,同时集群发展过程中创业者的社会资本发挥重要作用.这种将多维理论视角相结合起来进行分析的方法,有利于更好地理解产业集群的演进机制. 相似文献
53.
54.
Susan M. Sheridan Natalie A. Koziol Brandy L. Clarke Kristin M. Rispoli Michael J. Coutts 《Early education and development》2014,25(7):1057-1082
Research Findings: Children's early academic achievement is supported by positive social and behavioral skills, and difficulties with these skills frequently gives way to underachievement. Social and behavioral problems often arise as a product of parent–child interactional patterns and environmental influences. Few studies have examined the role of a salient aspect of children's environments, community locale, in the relationship between parenting practices and child outcomes. Using a large, nationally representative sample, we examined whether preschool parenting practices and children's social-behavioral skills in kindergarten were related to geographic setting (rural vs. city, suburban, and town). Results indicated that rural children experienced greater difficulties with parent-reported externalizing behaviors. Furthermore, rural parents displayed less emotional support than parents in other settings. Preschool parenting behaviors were associated with social skills and behavior problems in kindergarten, as reported by both parents and teachers. Parents' emotional supportiveness was found to account for the relationship between geographic setting and parent-reported children's social skills, such that rural parents who provided less emotional support had children with lower social skills in kindergarten. Practice or Policy: Findings of this research indicate that rural children may face particular risk for behavioral issues and highlight the need for increased behavioral supports in rural communities. Moreover, our results suggest that interventions designed to promote parents' support of children's emotions may have particular utility for rural families. 相似文献
55.
Jill Adler Sarmin Hossain Mary Stevenson John Clarke Rosa Archer Barry Grantham 《Journal of Mathematics Teacher Education》2014,17(2):129-148
This article reports an investigation into how students of a mathematics course for prospective secondary mathematics teachers in England talk about the notion of ‘understanding mathematics in depth’, which was an explicit goal of the course. We interviewed eighteen students of the course. Through our social practice frame and in the light of a review of the literature on mathematical knowledge for teaching, we describe three themes that weave through the students’ talk: reasoning, connectedness and being mathematical. We argue that these themes illuminate privileged messages in the course, as well as the boundary and relationship between mathematical and pedagogic content knowledge in secondary mathematics teacher education practice. 相似文献
56.
Benzodiazepine administration prevents the use of error-correction mechanisms during fear extinction
Genevra Hart Nathan M. Holmes Justin A. Harris R. Frederick Westbrook 《Learning & behavior》2014,42(4):383-397
Three experiments examined the effect of systemic administration of the benzodiazepine midazolam on extinction and re-extinction of conditioned fear. Experiment 1 demonstrated that midazolam administration prior to extinction of a conditioned stimulus (CS) impaired that extinction when rats were subsequently tested drug free; however, extinction was spared if rats were extinguished, reconditioned, and re-extinguished under midazolam. Experiment 2 provided a replication of this effect within-subjects; rats were conditioned to two CSs (A and B), extinguished to one (A-), reconditioned to both, and then extinguished/re-extinguished to both stimuli in compound (AB-), under either vehicle or midazolam. On the drug-free test, rats given midazolam froze more to the CS that had been extinguished (B) than the one that been re-extinguished (A). The final experiment examined whether extinction under midazolam was regulated by prediction error. Rats were trained with three CSs (A, B, C) and extinguished to two (A-, C-). These stimuli then underwent additional extinction under midazolam or vehicle, with one CS now presented in compound with the non-extinguished CS (AB-, C-). Rats were then tested for fear of A relative to C. Rats given vehicle showed a deepening of extinction to A relative to C, as is predicted from error-correction models; however, rats given midazolam failed to show any such discrepancy in responding. The results are interpreted to indicate that the drug reduced prediction error during extinction by reducing fear, and rats were able to re-extinguish fear via a retrieval mechanism that is independent of prediction error. 相似文献
57.
58.
Objectives: This article examines a strategic approach to developing e‐learning capability to enhance learning opportunities for the workforce of a healthcare organization. Emphasis is given to the procurement of a bespoke Managed Learning Environment (MLE). Strategic organizational issues impacting on future e‐learning developments are considered. Methods: The 2‐year implementation plan was evaluated through a two phase external research project. The first phase focused on the effectiveness of a training programme designed to build capacity for e‐learning within the Northern area and also included a virtual learning environment usability study which informed the MLE specification. The second phase evaluation is ongoing during 2005 and interim findings are presented. Results: The MLE has been piloted and on‐line learning packages have been acquired. There has been a phased take‐up of e‐learning opportunities and e‐tutor training. Some virtual Communities of Practice have been established. Key organizational issues have been identified and ongoing findings are informing strategic planning. Conclusions: The healthcare MLE is offering enhanced learning opportunities and assisting area healthcare providers in training their dispersed workforces. Blended learning strategies are most successful. The need for protected time for e‐learning is a key issue, financial savings are available. Progress has been slowed by identified organizational constraints—the MLE's benefits are widely recognized. 相似文献
59.
In this paper, a detailed numerical and experimental investigation into the optimisation of hydrodynamic micro-trapping arrays for high-throughput capture of single polystyrene (PS) microparticles and three different types of live cells at trapping times of 30 min or less is described. Four different trap geometries (triangular, square, conical, and elliptical) were investigated within three different device generations, in which device architecture, channel geometry, inter-trap spacing, trap size, and trap density were varied. Numerical simulation confirmed that (1) the calculated device dimensions permitted partitioned flow between the main channel and the trap channel, and further, preferential flow through the trap channel in the absence of any obstruction; (2) different trap shapes, all having the same dimensional parameters in terms of depth, trapping channel lengths and widths, main channel lengths and widths, produce contrasting streamline plots and that the interaction of the fluid with the different geometries can produce areas of stagnated flow or distorted field lines; and (3) that once trapped, any motion of the trapped particle or cell or a shift in its configuration within the trap can result in significant increases in pressures on the cell surface and variations in the shear stress distribution across the cell’s surface. Numerical outcomes were then validated experimentally in terms of the impact of these variations in device design elements on the percent occupancy of the trapping array (with one or more particles or cells) within these targeted short timeframes. Limitations on obtaining high trap occupancies in the devices were shown to be primarily a result of particle aggregation, channel clogging and the trap aperture size. These limitations could be overcome somewhat by optimisation of these device design elements and other operational variables, such as the average carrier fluid velocity. For example, for the 20 μm polystyrene microparticles, the number of filled traps increased from 32% to 42% during 5–10 min experiments in devices with smaller apertures. Similarly, a 40%–60% reduction in trapping channel size resulted in an increase in the amount of filled traps, from 0% to almost 90% in 10 min, for the human bone marrow derived mesenchymal stem cells, and 15%–85% in 15 min for the human embryonic stem cells. Last, a reduction of the average carrier fluid velocity by 50% resulted in an increase from 80% to 92% occupancy of single algae cells in traps. Interestingly, changes in the physical properties of the species being trapped also had a substantial impact, as regardless of the trap shape, higher percent occupancies were observed with cells compared to single PS microparticles in the same device, even though they are of approximately the same size. This investigation showed that in microfluidic single cell capture arrays, the trap shape that maximizes cell viability is not necessarily the most efficient for high-speed single cell capture. However, high-speed trapping configurations for delicate mammalian cells are possible but must be optimised for each cell type and designed principally in accordance with the trap size to cell size ratio. 相似文献
60.
Web hyperlink analysis has been a key topic of Webometric research. However, inlink data collection from commercial search engines has been limited to only one source in recent years, which is not a promising prospect for the future development of the field. We need to tap into other Web data sources and to develop new methods. Toward this end, we propose a new Webometrics concept that is based on words rather than inlinks on Webpages. We propose that word co-occurrences on Webpages can be a measure of the relatedness of organizations. Word co-occurrence data can be collected from both general search engines and blog search engines, which expands data sources greatly. The proposed concept is tested in a group of companies in the LTE and WiMax sectors of the telecommunications industry. Data on the co-occurrences of company names on Webpages were collected from Google and Google Blog. The co-occurrence matrices were analyzed using MDS. The resulting MDS maps were compared with industry reality and with the MDS maps from co-link analysis. Results show that Web co-word analysis could potentially be as useful as Web co-link analysis. Google Blog seems to be a better source than Google for co-word data collection. 相似文献