全文获取类型
收费全文 | 34595篇 |
免费 | 535篇 |
国内免费 | 21篇 |
专业分类
教育 | 24932篇 |
科学研究 | 3022篇 |
各国文化 | 300篇 |
体育 | 2770篇 |
综合类 | 18篇 |
文化理论 | 251篇 |
信息传播 | 3858篇 |
出版年
2021年 | 341篇 |
2020年 | 515篇 |
2019年 | 801篇 |
2018年 | 1117篇 |
2017年 | 1104篇 |
2016年 | 978篇 |
2015年 | 587篇 |
2014年 | 881篇 |
2013年 | 6654篇 |
2012年 | 885篇 |
2011年 | 960篇 |
2010年 | 656篇 |
2009年 | 661篇 |
2008年 | 814篇 |
2007年 | 682篇 |
2006年 | 697篇 |
2005年 | 572篇 |
2004年 | 519篇 |
2003年 | 497篇 |
2002年 | 526篇 |
2001年 | 733篇 |
2000年 | 624篇 |
1999年 | 571篇 |
1998年 | 312篇 |
1997年 | 348篇 |
1996年 | 384篇 |
1995年 | 385篇 |
1994年 | 308篇 |
1993年 | 341篇 |
1992年 | 505篇 |
1991年 | 471篇 |
1990年 | 466篇 |
1989年 | 493篇 |
1988年 | 451篇 |
1987年 | 462篇 |
1986年 | 428篇 |
1985年 | 478篇 |
1984年 | 397篇 |
1983年 | 407篇 |
1982年 | 331篇 |
1981年 | 305篇 |
1980年 | 290篇 |
1979年 | 440篇 |
1978年 | 340篇 |
1977年 | 299篇 |
1976年 | 283篇 |
1975年 | 246篇 |
1974年 | 250篇 |
1973年 | 236篇 |
1971年 | 226篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Valdivia WD 《Minerva》2011,49(1):25-46
Evaluation studies of the Bayh-Dole Act are generally concerned with the pace of innovation or the transgressions to the independence
of research. While these concerns are important, I propose here to expand the range of public values considered in assessing
Bayh-Dole and formulating future reforms. To this end, I first examine the changes in the terms of the Bayh-Dole debate and
the drift in its design. Neoliberal ideas have had a definitive influence on U.S. innovation policy for the last thirty years,
including legislation to strengthen patent protection. Moreover, the neoliberal policy agenda is articulated and justified
in the interest of “competitiveness.” Rhetorically, this agenda equates competitiveness with economic growth and this with
the public interest. Against that backdrop, I use Public Value Failure criteria to show that values such as political equality,
transparency, and fairness in the distribution of the benefits of innovation, are worth considering to counter the “policy
drift” of Bayh-Dole. 相似文献
972.
973.
974.
A series of light-fastness tests were conducted on a group of ethnographic objects that will be on exhibit at the Smithsonian Institution Arctic Studies Center, a recent addition to the Anchorage Museum at Rasmuson Center in Alaska. The objects surveyed belong to the collections of the Smithsonian National Museum of Natural History and the Smithsonian National Museum of the American Indian. This work was designed as a feasibility study on the use of a micro-fading tester as a non-contact and non-destructive technique to evaluate the light-stability of materials present in ethnographic collections. A broad range of objects containing a wide variety of materials were selected for the study. The materials investigated included a variety of dyes applied on silk, cotton, and wool substrates along with some unusual materials such as tanned skin and seal gut skin. The results from this investigation have allowed establishing exhibition recommendations taking into consideration the sensitivity of each object, light levels in the museum building, and estimated light exposures based on the duration of the exhibit. The micro-fading tester has proven to be a very useful tool for determining the light-stability of ethnographic materials without causing any harm to the objects. Objects containing equivalent materials are usually classified under a general category based on their probable sensitivity to light. However, micro-fading test results have permitted the detection of dissimilarities among some of these objects, which could be associated to variations in prior fading histories, the quality of raw materials, and different preparation methods. 相似文献
975.
D. Barker 《Sport, Education and Society》2019,24(2):134-146
Research suggests that physical education (PE) in Western countries is not providing equitable experiences for non-white students. Responsibility for shortcomings has often been ascribed to white PE teachers. Scholars have claimed that teachers lack cultural competence and know little about how physical cultures or health are understood by the young people with whom they work. The objective of this investigation was to investigate this claim and generate an understanding of how white PE teachers in a culturally diverse high school make sense of their work with non-white students. Data with three Swedish teachers of varying experience were produced using semi-structured interviewing. A series of school visits provided a complementary line of data. Four themes emerged from the data. These related to: (1) differences between white and non-white values; (2) the knowledge and dispositions necessary for success in PE; (3) the broad purpose of PE, and; (4) the differences between boys’ and girls’ experiences of PE. Data were interpreted using a Critical Race Theory (CRT) perspective, with the notion of ‘whiteness’ providing a specific analytic concept. The general thesis developed in the second part of the paper is that problems result not from insensitivity or incompetence but from discourses of whiteness in which many teachers live and work. By building on critical research both in general education and physical education literature and by utilizing whiteness as an analytical concept, the investigation shows how three PE teachers draw extensively on the racial discourse of whiteness and how this disadvantages non-white students. The paper is concluded with a consideration of how racial disadvantage could be challenged or disrupted. 相似文献
976.
James H. Dugdale Calum A. Arthur Dajo Sanders Angus M. Hunter 《European Journal of Sport Science》2019,19(6):745-756
This study aimed to establish between-day reliability and validity of commonly used field-based fitness tests in youth soccer players of varied age and playing standards, and to discriminate between players without (“unidentified”) or with (“identified”) a direct route to professional football through their existing club pathway. Three-hundred-and-seventy-three Scottish youth soccer players (U11–U17) from three different playing standards (amateur, development, performance) completed a battery of commonly used generic field-based fitness tests (grip dynamometry, standing broad jump, countermovement vertical jump, 505 (505COD) and T-Drill (T-Test) change of direction and 10/20 m sprint tests) on two separate occasions within 7–14?days. The majority of field-based fitness tests selected within this study proved to be reliable measures of physical performance (ICC?=?0.83–0.97; p?.01). However, COD tests showed weaker reliability in younger participants (ICC?=?0.57–0.79; p?.01). The field-based fitness testing battery significantly discriminated between the unidentified and identified players; χ2 (7)?=?101.646, p?.001, with 70.2% of players being correctly classified. We have shown field-based fitness tests to be reliable measures of physical performance in youth soccer players. However, results from the 505COD and T-Test change of direction tests may be more variable in younger players, potentially due to complex demands of these tests and the limited training age established by these players. While the testing battery selected in this study was able to discriminate between unidentified and identified players, findings were inconsistent when attempting to differentiate between individual playing standards within the “identified” player group (development vs. performance). 相似文献
977.
Transitioning into faculty roles can be a challenging experience. Responsibilities related to teaching, research, and service can be difficult to balance, and mismatch between personal preferences for work focus and instructional expectations can be problematic. This is particularly true of visiting assistant professors who want to work toward tenure-track positions, but whose current job focus is on teaching. Through transformative learning theory and employing the methodologies of self-study, we sought to understand the experiences of Kevin, the second author and a first-year visiting assistant professor. We draw data from Kevin's reflective journal and discussions between Kevin and his critical friend, Jim. Themes included (a) becoming an academic, (b) a hard-wired disposition toward work, and (c) influence of the VAP on emotional and personal health. Results are discussed through the lens of transformative learning theory and focus on Kevin's growth during his year as a visiting assistant professor. 相似文献
978.
Leg amputation side determines performance in curve sprinting: a case study on a Paralympic medalist
Johannes Funken Kai Heinrich Steffen Willwacher Ralf Müller Jonas Böcker Hiroaki Hobara 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(1):75-87
The lower limb kinetics of curve sprinting in amputees are not well described in the literature, particularly with respect to the effect of the side of amputation. This is an issue due to the importance of the knowledge for prosthetic design and classification of athletes. Thus, the aim of this study was to investigate the influence of side of amputation on curve sprinting performance in athletes with a unilateral leg amputation. A three-dimensional motion analysis system (Vicon), four force plates (Kistler) and a modified mathematical human model (ALASKA) were used to compare clockwise and counter clockwise curve sprinting lower limb kinematics and kinetics of a Paralympic medalist with a left-sided knee exarticular amputation. Results reveal that vertical ground reaction force application and total vertical impulse were lower when the affected limb was at the inside of the curve. The unaffected limb showed joint mechanics different to those established for non-amputee athletes and might contribute better to propulsion when being the inside limb. Curve sprinting biomechanics and the ability to attain high radial velocities are directly dependent on the side of amputation relative to the curve direction in a unilateral amputee athlete of highest performance level. 相似文献
979.
The aim of this study was to examine the impact of contextual factors on relative locomotor and metabolic power distances during professional female soccer matches. Twenty-eight players (forwards, n?=?4; midfielders, n?=?12; defenders, n?=?12) that competed in a 90-min home and away match (regular season only). The generalised estimating equations (GEE) was used to evaluate relative locomotor and metabolic power distances for three contextual factors: location (home vs. away), type of turf (natural vs. artificial), and match outcome (win, loss and draw). No differences were observed for home vs. away matches. Moderate-intensity running (20.0?±?1.0?m?min?1 and 16.4?±?0.9?m?min?1), high-intensity running (8.6?±?0.4?m?min?1 and 7.3?±?0.4?m?min?1) and high-metabolic power (16.3?±?0.5?m?min?1 and 14.4?±?0.5?m?min?1) distances were elevated on artificial turf compared to natural grass, respectively. Relative sprint distance was greater during losses compared with draws (4.3?±?0.4?m?min?1 and 3.4?±?0.3?m?min?1). Overall physical demands of professional women’s soccer were not impacted by match location. However, the elevation of moderate and high-intensity demands while playing on artificial turf may have implications on match preparations as well as recovery strategies. 相似文献
980.
Yoann M. Garnier Christos Paizis Romuald Lepers 《European Journal of Sport Science》2019,19(2):166-176
The present study assessed neuromuscular and corticospinal changes during and after a fatiguing submaximal exercise of the knee extensors in different modes of muscle contraction. Twelve subjects performed two knee extensors exercises in a concentric or eccentric mode, at the same torque and with a similar total impulse. Exercises consisted of 10 sets of 10 repetitions at an intensity of 80% of the maximal voluntary isometric contraction torque (MVIC). MVIC, maximal voluntary activation level (VAL) and responses of electrically evoked contractions of the knee extensors were assessed before and after exercise. Motor evoked potential amplitude (MEP) and cortical silent period (CSP) of the vastus medialis (VM) and rectus femoris (RF) muscles were assessed before, during and after exercise. Similar reductions of the MVIC (?13%), VAL (?12%) and a decrease in the peak twitch (?12%) were observed after both exercises. For both VM and RF muscles, MEP amplitude remained unchanged during either concentric or eccentric exercises. No change of the MEP amplitude input–output curves was observed post-exercise. For the RF muscle, CSP increased during the concentric exercise and remained lengthened after this exercise. For the VM muscle, CSP was reduced after the eccentric exercise only. For a similar amount of total impulse, concentric and eccentric knee extensor contractions led to similar exercise-induced neuromuscular response changes. For the two muscles investigated, no modulation of corticospinal excitability was observed during or after either concentric or eccentric exercises. However, intracortical inhibition showed significant modulations during and after exercise. 相似文献