全文获取类型
收费全文 | 11448篇 |
免费 | 103篇 |
国内免费 | 26篇 |
专业分类
教育 | 7880篇 |
科学研究 | 1461篇 |
各国文化 | 46篇 |
体育 | 724篇 |
综合类 | 13篇 |
文化理论 | 178篇 |
信息传播 | 1275篇 |
出版年
2022年 | 57篇 |
2021年 | 66篇 |
2020年 | 128篇 |
2019年 | 184篇 |
2018年 | 907篇 |
2017年 | 960篇 |
2016年 | 693篇 |
2015年 | 222篇 |
2014年 | 262篇 |
2013年 | 1302篇 |
2012年 | 293篇 |
2011年 | 505篇 |
2010年 | 482篇 |
2009年 | 318篇 |
2008年 | 371篇 |
2007年 | 509篇 |
2006年 | 158篇 |
2005年 | 229篇 |
2004年 | 275篇 |
2003年 | 207篇 |
2002年 | 135篇 |
2001年 | 187篇 |
2000年 | 203篇 |
1999年 | 146篇 |
1998年 | 119篇 |
1997年 | 108篇 |
1996年 | 111篇 |
1995年 | 60篇 |
1994年 | 77篇 |
1993年 | 52篇 |
1992年 | 119篇 |
1991年 | 111篇 |
1990年 | 89篇 |
1989年 | 98篇 |
1988年 | 107篇 |
1987年 | 88篇 |
1986年 | 110篇 |
1985年 | 106篇 |
1984年 | 89篇 |
1983年 | 90篇 |
1982年 | 84篇 |
1981年 | 61篇 |
1979年 | 81篇 |
1978年 | 78篇 |
1977年 | 57篇 |
1976年 | 58篇 |
1974年 | 54篇 |
1973年 | 45篇 |
1972年 | 49篇 |
1971年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
The analysis results for the basic indicators of innovative activities in the All-Russian Institute for Scientific and Technical Information (VINITI), Russian Academy of Science, are given. Suggestions for optimization are provided and the plan of innovative activities of VINITI is drawn on the basis on the analysis results, which is aimed at the further development of the institute. 相似文献
92.
Though there is a long tradition of band members quitting the group or taking a hiatus, the rock group as an organization to produce music continues to be both popular and economically viable. The research question addressed in this paper is whether or not it is a good idea to quit or take a hiatus from the group. We begin with a discussion of the framework for understanding why groups are formed and why they may be difficult to keep together. We then discuss differences between groups in the decade of the 1960s versus today. We argue that there is something unique about the output of the group even with the changes in the structure of contracts, compensation, and consumer focus on the artist that explain the resilience of the rock band as an organizational form within which to create music. We compare the charting success of bands that have members leave the group with the charting success of the members who left the group. We identified the groups in five representative years: 1965, 1975, 1985, 1995, and 2005. We then analyzed the entire Billboard Hot 100 charting careers of those groups and the artists who quit those groups. Our main finding is that when charting success is divided equally among members, going solo pays off—there is a clear economic rationale because solo acts have greater average charting success than the original bands they started in. The other ensuing side projects: duos, collaborations, and other groups are not as lucrative as the original bands. These findings are valid for members of charting groups from each of the 5 years examined. Despite the difficulties in keeping a rock band together, there are fewer band breakups today and remaining with the group generally results in a longer and more productive charting career. Thus, the rock group remains an important organization for producing contemporary music. However, there remains a compelling incentive to go solo. Superstars may benefit from solo projects, but for the average, non-superstar group member, in many circumstances it is better for the band to stay together if the income is divided equally. 相似文献
93.
94.
K. R. Shivanna 《Resonance》2016,21(11):1007-1018
After the pollen grain reaches the stigma through outsourced agents (pollinators), the next step before fertilization is to select the right type of pollen. Similar to a marriage in human beings, fiowering plants also have evolved elaborate screening process to select the right pollen grains and to reject the wrong ones. Even after initial screening for the right pollen, the pistil imposes a tough competition amongst them, comparable to a swayamvara of Indian mythology, to select the best available pollen. Flowering plants have evolved into a matriarchal society. The selection of the male partner is totally the prerogative of the mother (pistil); the boy (pollen grain) and the girl (ovule) has no say in this selection. 相似文献
95.
Given that physical activity (PA) tends to decrease with age during adolescence, addressing factors that affect change is important. This study examined the similarity and interdependence of PA as influenced by psychosocial factors among adolescent best friend dyads. A total of 660 adolescents, representing 330 best friend dyads, completed questionnaires with regard to PA, sitting time, perceived exercise benefits and barriers, physical self-perception and social support for PA. Dyads were also identified as reciprocal and non-reciprocal best friends; reciprocal means that both considered each other best friends and non-reciprocal were those in which only one considered the other a best friend. Data were analysed using a hierarchical linear model framework. Results indicated significant similarities between reciprocal best friend dyads for PA and sitting time, and for sitting time in non-reciprocal best friends (P values <.01). Psychosocial variables were associated with PA in reciprocal best friend dyads and with sitting time in reciprocal and non-reciprocal best friend dyads. Best friend gender, regular sports practice of the person, perceived exercise barriers of the best friend and best friend social support were the best predictors for PA. 相似文献
96.
Abbie E. Smith-Ryan Eric T. Trexler Hailee L. Wingfield Malia N.M. Blue 《Journal of sports sciences》2016,34(21):2038-2046
The purpose of this study was to evaluate two practical interval training protocols on cardiorespiratory fitness, lipids and body composition in overweight/obese women. Thirty women (mean ± SD; weight: 88.1 ± 15.9 kg; BMI: 32.0 ± 6.0 kg · m2) were randomly assigned to ten 1-min high-intensity intervals (90%VO2 peak, 1 min recovery) or five 2-min high-intensity intervals (80–100% VO2 peak, 1 min recovery) or control. Peak oxygen uptake (VO2 peak), peak power output (PPO), body composition and fasting blood lipids were evaluated before and after 3 weeks of training, completed 3 days per week. Results from ANCOVA analyses demonstrated no significant training group differences for any primary variables (P > 0.05). When training groups were collapsed, 1MIN and 2MIN resulted in a significant increase in PPO (?18.9 ± 8.5 watts; P = 0.014) and time to exhaustion (?55.1 ± 16.4 s; P = 0.001); non-significant increase in VO2 peak (?2.36 ± 1.34 ml · kg?1 · min?1; P = 0.185); and a significant decrease in fat mass (FM) (??1.96 ± 0.99 kg; P = 0.011). Short-term interval exercise training may be effective for decreasing FM and improving exercise tolerance in overweight and obese women. 相似文献
97.
1.Introduction
The reproduction systems of 3D images without using eyeglasses and other special accessories has always attracted attention and aroused great interest of developers and consumers of such equipment because of totally accurate image and method of its presentation.Such systems can be used and are already partially used in advertising,television,different devices (i.e.smartphones,tablet computers),at the exhibitions,etc.,as well as in various technical applications,training systems,simulators,etc. 相似文献
98.
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
99.
David S. Haydon Ross A. Pinder Paul N. Grimshaw William S. P. Robertson 《Sports Engineering》2016,19(3):177-184
Limited recommendations of wheelchair configurations for court sports have been identified in the published literature. To accommodate the wide range of impairments in wheelchair rugby, players are given a point score that reflects their impairment. Players have regularly been grouped as high-, mid-, or low-point players in research, with high-point players having greater levels of muscle function compared with other classifications. This research documented the wheelchair configurations of elite Australian wheelchair rugby players across classification groups. Significant differences (p < 0.05) were found for increased seat height and decreased seat depth for high-point players compared with low- and mid-point groups, respectively. Low-point players displayed reduced wheelchair mass compared with high- and mid-point players, as well as increased frame length. Camber angles showed no significant differences across the classification groups. The incorporation of anthropometric measures, such as the elbow angle at the top dead center, was also investigated. While elbow angle showed no significant differences, seat height-to-total arm length ratio was higher for high-point players. Participants also completed surveys detailing their perception of the effect of altering wheelchair configurations. It is suggested that wheelchair configurations should consider an individual’s anthropometrics, impairment, training history, and court role to promote optimal performance, with predictive modeling having the potential to reduce the associated time and cost. 相似文献
100.