全文获取类型
收费全文 | 2721篇 |
免费 | 52篇 |
国内免费 | 6篇 |
专业分类
教育 | 1909篇 |
科学研究 | 207篇 |
各国文化 | 60篇 |
体育 | 261篇 |
综合类 | 4篇 |
文化理论 | 34篇 |
信息传播 | 304篇 |
出版年
2023年 | 11篇 |
2022年 | 12篇 |
2021年 | 30篇 |
2020年 | 47篇 |
2019年 | 80篇 |
2018年 | 142篇 |
2017年 | 120篇 |
2016年 | 112篇 |
2015年 | 81篇 |
2014年 | 94篇 |
2013年 | 564篇 |
2012年 | 93篇 |
2011年 | 119篇 |
2010年 | 77篇 |
2009年 | 79篇 |
2008年 | 76篇 |
2007年 | 68篇 |
2006年 | 54篇 |
2005年 | 69篇 |
2004年 | 68篇 |
2003年 | 49篇 |
2002年 | 51篇 |
2001年 | 37篇 |
2000年 | 54篇 |
1999年 | 26篇 |
1998年 | 30篇 |
1997年 | 30篇 |
1996年 | 31篇 |
1995年 | 33篇 |
1994年 | 27篇 |
1993年 | 34篇 |
1992年 | 18篇 |
1991年 | 12篇 |
1990年 | 31篇 |
1989年 | 15篇 |
1988年 | 18篇 |
1987年 | 18篇 |
1986年 | 13篇 |
1985年 | 20篇 |
1984年 | 25篇 |
1983年 | 16篇 |
1982年 | 16篇 |
1981年 | 17篇 |
1980年 | 17篇 |
1979年 | 13篇 |
1978年 | 11篇 |
1977年 | 10篇 |
1974年 | 11篇 |
1973年 | 13篇 |
1972年 | 8篇 |
排序方式: 共有2779条查询结果,搜索用时 15 毫秒
31.
32.
Chi (1992, 1993) Chi et al. (1994) suggests that many of the difficulties encountered by students in learning Physics concepts arise because they attribute the ontology of material substances to these concepts. These concepts are actually a special type of process - 'Constraint-Based Interactions' (CBI). Slotta and Chi (1996) reported on a study where a group of students explicitly trained in the CBI ontology showed significant gains over a control group in problem solving performance in eight simple electric circuit problems. This paper reports on a series of four studies which explore the usefulness of the ontological categorization framework in investigating students' alternative conceptions of electric circuits and in developing a teaching strategy for promoting conceptual change in the learning of basic electric circuitry concepts. 相似文献
33.
Software engineering education can be viewed as a challenging task. Computer science students tend to focus on the programming aspects of a project, and take a “hacking approach” to completing a project, rather than viewing the process. Our course material includes teaching the Personal Software Process (PSP). Students are required to produce defect and effort metrics, as well as project summary reports. Tools to assist information recording and production of reports are difficult for students to access. The cost in terms of financial and learning time is usually too high at the educational level to justify using commercial tools that are available for the professional software engineer. We have developed a tool—Personal Assistant for Software Engineers—to aid students in the learning of the PSP. The tool has been successfully used in four subjects for a semester. Following feedback and evaluation, it has been redesigned, and is currently in stage two. The tool has been useful for students, and has automated the previous manual process of producing time and defect reports, along with project summaries, thus allowing them to focus on the meaning of the information. 相似文献
34.
35.
36.
Birgit Angelika Schmidt Martin Andreas Ziemann Simone Pentzien Toralf Gabsch Werner Koch Jörg Krüger 《文物保护研究》2016,61(2):113-122
A great number of Central Asian wall paintings, archeological materials, architectural fragments, and textiles, as well as painting fragments on silk and paper, make up the so called Turfan Collection at the Asian Art Museum in Berlin. The largest part of the collection comes from the Kucha region, a very important cultural center in the third to ninth centuries. Between 1902 and 1914, four German expeditions traveled along the northern Silk Road. During these expeditions, wall paintings were detached from their original settings in Buddhist cave complexes. This paper reports a technical study of a wall painting, existing in eight fragments, from the Buddhist cave no. 40 (Ritterhöhle). Its original painted surface is soot blackened and largely illegible. Grünwedel, leader of the first and third expeditions, described the almost complete destruction of the rediscovered temple complex and evidence of fire damage. The aim of this case study is to identify the materials used for the wall paintings. Furthermore, soot deposits as well as materials from conservation interventions were of interest. Non-invasive analyses were preferred but a limited number of samples were taken to provide more precise information on the painting technique. By employing optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, micro X-ray fluorescence spectroscopy, X-ray diffraction analysis, and Raman spectroscopy, a layer sequence of earthen render, a ground layer made of gypsum, and a paint layer containing a variety of inorganic pigments were identified. 相似文献
37.
This study is designed to identify the underlying satisfaction dimensions gained through engagement in target shooting as a serious leisure pastime. The instrument design was based on the Leisure Satisfaction Scale. A total of 5502 useable surveys were collected through the Internet and a website related to target shooting and gun ownership. The results revealed eight dimensions: self-actualization, social interaction, location aesthetic, respite, physical benefit, connection and hedonic pleasure, which supplied the primary satisfiers of engaging in target shooting as a serious leisure activity. The demographic profile and dimensions of satisfaction may serve to dispel commonly held stereotypes of shooting hobbyists and those involved in gun ownership. The findings have important implications for leisure researchers and practitioners, to industry, both leisure and firearm related, and the target shooting community at large. This study adds to the literature of both target shooting and serious leisure. 相似文献
38.
Martin Schnitzer Benjamin Bodner Sabrina Scheiber Erich Thöni Martin Kopp 《Sportwissenschaft》2016,46(1):26-33
The aim of this article is to gain insights into the economic impacts of the Winter Youth Olympic Games (YOG). Taking the example of Innsbruck 2012 (YOG 2012)—the first ever Winter YOG—the economic dimension of the event is comprised by calculating the primary economic impulse as well as the induced economic impulse (total economic effect). For the purpose of this study the region (Tirol) and the period of time (13th to 22th January 2012) were chosen. 相似文献
39.
The main purpose of this article is to advance an alternative perspective on the relationship between intrinsic and extrinsic motivation, and in particular to examine critically the assertion that these processes are antagonistic such that the will to learn for its own sake is inhibited by the presence of extrinsic, tangible rewards and incentives such as school grades. The presumption of an antagonistic relationship largely depends on the theoretical perspective adopted. An alternative interpretation based on need achievement theory leads to distinctly different conclusions. Exploring this new perspective allows one to identify both the conditions under which intrinsic motives may coexist with extrinsic motives as well as to consider some of the means by which intrinsic motives and caring about learning can be stimulated in their own right in school settings. 相似文献
40.
Eric C. Haakonssen Martin Barras Louise M. Burke David G. Jenkins David T. Martin 《European Journal of Sport Science》2016,16(6):645-653
The aims of this study were to describe normative values and seasonal variation of body composition in female cyclists comparing female road and track endurance cyclists, and to validate the use of anthropometry to monitor lean mass changes. Anthropometric profiles (seven site skinfolds) were measured over 16 years from 126 female cyclists. Lean mass index (LMI) was calculated as body weight?×?skinfolds?x. The exponent (x) was calculated as the slope of the natural logarithm of body weight and skinfolds. Percentage changes in LMI were compared to lean mass changes measured using dual-energy X-ray absorptiometry (DXA) in a subset of 25 road cyclists. Compared to sub-elite and elite cyclists, world class cyclists were (mean [95% CI]) 1.18?kg [0.46, 1.90] and 0.60?kg [0.05, 1.15] lighter and had skinfolds that were 7.4?mm [3.8, 11.0] and 4.6?mm [1.8, 7.4] lower, respectively. Body weight (0.41?kg [0.04, 0.77]) and skinfolds (4.0?mm [2.1, 6.0]) were higher in the off-season compared to the early-season. World class female road cyclists had lower body weight (6.04?kg [2.73, 9.35]) and skinfolds (11.5?mm [1.1, 21.9]) than track endurance cyclists. LMI (mean exponent 0.15 [0.13, 0.18]) explained 87% of the variance in DXA lean mass. In conclusion, higher performing female cyclists were lighter and leaner than their less successful peers, road cyclists were lighter and leaner than track endurance cyclists, and weight and skinfolds were lowest early in the season. LMI appears to be a reasonably valid tool for monitoring lean mass changes. 相似文献