全文获取类型
收费全文 | 1847篇 |
免费 | 17篇 |
专业分类
教育 | 1537篇 |
科学研究 | 24篇 |
各国文化 | 14篇 |
体育 | 232篇 |
综合类 | 2篇 |
文化理论 | 3篇 |
信息传播 | 52篇 |
出版年
2019年 | 9篇 |
2018年 | 17篇 |
2017年 | 20篇 |
2016年 | 9篇 |
2015年 | 23篇 |
2014年 | 62篇 |
2013年 | 460篇 |
2012年 | 73篇 |
2011年 | 73篇 |
2010年 | 76篇 |
2009年 | 89篇 |
2008年 | 34篇 |
2007年 | 39篇 |
2006年 | 52篇 |
2005年 | 16篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 10篇 |
2001年 | 6篇 |
2000年 | 14篇 |
1999年 | 17篇 |
1998年 | 15篇 |
1997年 | 14篇 |
1996年 | 41篇 |
1995年 | 90篇 |
1994年 | 48篇 |
1993年 | 50篇 |
1992年 | 60篇 |
1991年 | 57篇 |
1990年 | 39篇 |
1989年 | 18篇 |
1988年 | 11篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1984年 | 11篇 |
1983年 | 5篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 19篇 |
1979年 | 57篇 |
1978年 | 38篇 |
1977年 | 43篇 |
1976年 | 21篇 |
1975年 | 18篇 |
1974年 | 20篇 |
1973年 | 6篇 |
1972年 | 8篇 |
1971年 | 4篇 |
1970年 | 3篇 |
1962年 | 8篇 |
排序方式: 共有1864条查询结果,搜索用时 15 毫秒
91.
The geography of opportunity: spatial heterogeneity in founding rates and the performance of biotechnology firms 总被引:3,自引:0,他引:3
One of the most commonly observed features of the organization of markets is that similar business enterprises cluster in physical space. In this paper, we develop an explanation for firm co-location in high-technology industries that draws upon a relational account of new venture creation. We argue that industries cluster because entrepreneurs find it difficult to leverage the social ties necessary to mobilize essential resources when they reside far from those resources. Therefore, opportunities for high tech entrepreneurship mirror the distribution of critical resources. The same factors that enable high tech entrepreneurship, however, do not necessary promote firm performance. In the empirical analyses, we investigate the effects of geographic proximity to established biotechnology firms, sources of biotechnology expertise (highly-skilled labor), and venture capitalists on the location-specific founding rates and performance of biotechnology firms. The paper finds that the local conditions that promote new venture creation differ from those that maximize the performance of recently established companies. 相似文献
92.
93.
94.
95.
96.
97.
98.
Regarding the phenomenon of mood improvements through physical exercise, secondary analyses indicate that improvements can hardly be generalised. Rather, personal and situational factors need to be taken into consideration in order to define the effects in a more precise manner. This contribution investigates to what extent explicit motives and goals of individuals in middle adulthood can be considered as personal moderators of mood changes. Five exercise programmes were developed in a quasi-experimental design and were conducted over a 3-month intervention period. These programmes were based on the “motive-based types of sportsperson” (Sudeck, Lehnert & Conzelmann, 2011), which define groups of individuals with similar motive and goal profiles. One hundred and thirty-three individuals participated in either a programme tailor-made to their motive and goal profile or in a non-tailored programme. The influence of this motive-based tailoring was investigated based on the mood dimensions of valence, calmness and positive activation using handheld PCs during and after exercise sessions. Results indicate a moderating influence of explicit motives and goals. This moderation was however not a general one but rather depended on the exercise programmes’ specific goals and content as well as on individuals’ goals regarding recreation. These findings point towards a systematic consideration of explicit motives and goals in the planning of health and leisure sport programmes. 相似文献
99.
Prof. Dr. Sigrid Blömeke Prof. Dr. Johannes König Dr. Andreas Busse Dr. Ute Suhl Jessica Benthien Prof. Dr. Martina Döhrmann Prof. Dr. Gabriele Kaiser 《Zeitschrift für Erziehungswissenschaft》2014,17(3):509-542
The transition from teacher training into the teaching profession is seen to be key in the biography of a teacher. Yet there is a lack of enquiry into the development of the content knowledge (CK) and pedagogical content knowledge (PCK) held by teachers at the end of their education, and into the significance of this knowledge for situational and behavioural cognition. On the basis of data from the international comparative study TEDS-M 2008 and the Germany-based 2012 follow-up, this contribution investigates the knowledge and skills development of teachers during the transition from teacher training to the teaching profession in a four-year longitudinal study with n = 171 mathematics teachers. Three test formats (paper-and-pencil, video-vignettes and speed tests) are used to examine various indicators for teacher expertise. In addition to the analysis of changes in mathematical CK and PCK levels, path analysis is used to determine the extent to which this knowledge functions as a predictor for the perception and interpretation of classroom situations, the decision-making in these situations, and the quick identification of student mistakes. The results show only small changes in the group mean (for MCK there is a small loss, whereas MPCK remains constant), but high fluctuation (i. e. weak correlation) in the MPCK ranking between the two measurement occasions, pointing to differential learning effects gained from teaching practice. There are also significant differences in predictability: MCK is important for the speed indicators of teacher expertise; MCK and MPCK for the perception and interpretation of situations, and for the generation of action strategies. These findings can on the one hand help to facilitate the evaluation of beginning teachers’ need for support and, on the other hand, they indicate the necessity for the early integration of practice-based elements into teacher training programmes with the aim of developing PCK and related skills. 相似文献
100.
Tanja Link Eva Johanna Schwarz Stefan Huber Dr. Ursula Fischer Prof. Dr. Hans-Christoph Nuerk Prof. Dr. Ulrike Cress Prof. Dr. Korbinian Moeller 《Zeitschrift für Erziehungswissenschaft》2014,17(2):257-277
Basic numerical representations are seen as the building block for the successful development of more complex numerical and arithmetic competencies. Extending previous studies focusing on improving basic numerical representations by means of embodied training schemes, the current study focused on an embodied training of children’s place-value understanding. In this vein, 49 secondgraders were trained on solving a number line estimation task by stepping on different fields of a dance mat allowing for separate estimations of tens and units with more effort needed to step on the tens. In a partially randomized cross-over design, two control conditions were used to controll for training effects caused exclusively by the numerical content trained or the use of the dance mat. Interestingly, results revealed specific training effects after both the embodied and the control conditions. However, training effects were significantly more pronounced after the embodied training, thereby providing further evidence for the benefit of an embodied training of the place-value structure of the Arabic number system. 相似文献