首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4150篇
  免费   89篇
  国内免费   3篇
教育   3368篇
科学研究   169篇
各国文化   66篇
体育   173篇
综合类   1篇
文化理论   33篇
信息传播   432篇
  2023年   31篇
  2022年   42篇
  2021年   71篇
  2020年   130篇
  2019年   181篇
  2018年   252篇
  2017年   239篇
  2016年   216篇
  2015年   128篇
  2014年   182篇
  2013年   897篇
  2012年   150篇
  2011年   135篇
  2010年   127篇
  2009年   124篇
  2008年   112篇
  2007年   106篇
  2006年   117篇
  2005年   99篇
  2004年   94篇
  2003年   61篇
  2002年   62篇
  2001年   49篇
  2000年   35篇
  1999年   51篇
  1998年   41篇
  1997年   36篇
  1996年   49篇
  1995年   30篇
  1994年   34篇
  1993年   21篇
  1992年   22篇
  1991年   25篇
  1990年   24篇
  1989年   16篇
  1988年   15篇
  1987年   19篇
  1986年   17篇
  1985年   21篇
  1984年   14篇
  1983年   8篇
  1982年   14篇
  1981年   15篇
  1980年   9篇
  1979年   20篇
  1978年   8篇
  1977年   16篇
  1975年   7篇
  1974年   8篇
  1973年   7篇
排序方式: 共有4242条查询结果,搜索用时 0 毫秒
61.
Differences in infant outcome, predictor variables, and their relationships were explored as a function of maternal employment. Thirty 18-month-olds and their mothers were studied. Child intelligence, attachment security, and dependency were measured, as well as frequency of stressful events in the mother's life, quality of the parents' marital relationship, frequency of the mother's social contacts, and extent of the mother's emotional and parenting supports. Also included were the mother's ability to cope; satisfaction with emotional, parenting, and child care supports; and role satisfaction. For children of employed mothers, attachment and dependency were negatively correlated; securely attached children showed less dependency behavior. For employed mothers, satisfaction with child care and frequent social contacts predicted secure child attachment. Satisfaction with child care, role satisfaction, and ability to cope were strongly interrelated. For nonemployed mothers, maternal coping predicted attachment security, while frequent social contacts predicted greater child dependency. Predictors of child outcome were highly interrelated for nonemployed mothers, with satisfaction with emotional supports playing a pivotal role. These differences suggest that different models to predict infant outcome in employed and nonemployed mother families may be appropriate.  相似文献   
62.
This study examined the separate and combined effects of heat acclimation and hand cooling on post-exercise cooling rates following bouts of exercise in the heat. Seventeen non-heat acclimated (NHA) males (mean ± SE; age, 23 ± 1 y; mass, 75.30 ± 2.27 kg; maximal oxygen consumption [VO2 max], 54.1 ± 1.3 ml·kg?1·min?1) completed 2 heat stress tests (HST) when NHA, then 10 days of heat acclimation, then 2 HST once heat acclimated (HA) in an environmental chamber (40°C; 40%RH). HSTs were 2 60-min bouts of treadmill exercise (45% VO2 max; 2% grade) each followed by 10 min of hand cooling (C) or no cooling (NC). Heat acclimation sessions were 90–240 min of treadmill or stationary bike exercise (60–80% VO2 max). Repeated measures ANOVA with Fishers LSD post hoc (α < 0.05) identified differences. When NHA, C (0.020 ± 0.003°C·min?1) had a greater cooling rate than NC (0.013 ± 0.003°C·min?1) (mean difference [95%CI]; 0.007°C [0.001,0.013], P = 0.035). Once HA, C (0.021 ± 0.002°C·min?1) was similar to NC (0.025 ± 0.002°C·min?1) (0.004°C [?0.003,0.011], P = 0.216). Hand cooling when HA (0.021 ± 0.002°C·min?1) was similar to when NHA (0.020 ± 0.003°C·min?1) (P = 0.77). In conclusion, when NHA, C provided greater cooling rates than NC. Once HA, C and NC provided similar cooling rates.  相似文献   
63.
The ACL-Return to Sport after Injury scale (ACL-RSI) measures athletes’ emotions, confidence in performance, and risk appraisal in relation to return to sport after ACL reconstruction. Aim of this study was to study the validity and reliability of the Dutch version of the ACL-RSI (ACL-RSI (NL)).

Total 150 patients, who were 3–16 months postoperative, completed the ACL-RSI(NL) and 5 other questionnaires regarding psychological readiness to return to sports, knee-specific physical functioning, kinesiophobia, and health-specific locus of control. Construct validity of the ACL-RSI(NL) was determined with factor analysis and by exploring 10 hypotheses regarding correlations between ACL-RSI(NL) and the other questionnaires. For test–retest reliability, 107 patients (5–16 months postoperative) completed the ACL-RSI(NL) again 2 weeks after the first administration. Cronbach’s alpha, Intraclass Correlation Coefficient (ICC), SEM, and SDC, were calculated. Bland–Altman analysis was conducted to assess bias between test and retest.

Nine hypotheses (90%) were confirmed, indicating good construct validity. The ACL-RSI(NL) showed good internal consistency (Cronbach’s alpha 0.94) and test–retest reliability (ICC 0.93). SEM was 5.5 and SDC was 15. A significant bias of 3.2 points between test and retest was found.

Therefore, the ACL-RSI(NL) can be used to investigate psychological factors relevant to returning to sport after ACL reconstruction.  相似文献   

64.
Abstract

Sport history is a subfield well positioned to involve and benefit from an interdisciplinary approach to historical actors and spaces. Through the use of personal research and teaching experiences that focuses on the intersection between environmental history and those of sport, this piece explores the value in such an interdisciplinary structure through the examples of researching golf courses as transnational sporting landscapes and of teaching sport and leisure cultures to a diverse student body with high levels of engagement.  相似文献   
65.
66.
Attaining high speed of the stick head and consequently of the ball is essential for successful performance of the drag flick in field hockey, but the coordination pattern used to maximise stick head speed is unknown. The kinematics of the drag flick was studied in ten elite hockey players who performed twenty shots each towards a target located 1.5 m high. A 150 Hz active marker motion analysis system was used, alongside two force plates to detect foot touchdown. Angular velocity and contribution to stick endpoint speed of upper body joints were analysed. Repeated measures ANOVA was used to compare timing of onset and peak angular velocities between joints. Participants used a kinematic pattern that was close to a proximal-to-distal sequence. Trunk axial rotation and lateral rotation towards the target, right wrist flexion and left wrist extension were the main contributors to stick endpoint speed. Coaches should emphasise trunk rotations and wrist flexion and extension movements for maximising stick head speed. Given the high level of the participants in this study, the coordination of joints motions, as reported here, can serve as a guideline for drag flick training.  相似文献   
67.
Arts participation bears the threefold imprint of time: people's life stage (age), their earlier socializing imprint (cohort) and the historical circumstances of the moment (period). A proper understanding of these three effects is of great importance in understanding the present and future sizes and preferences of arts audiences. Such understanding implies disentangling those three effects properly, rather than overlooking or confusing them. An example of how that might be done is presented here with regard to arts participation in the US.  相似文献   
68.
69.
70.
Desalination is a relatively new intervention in the field of conservation of architectural heritage. Especially the desalination of immovable objects, such as masonry structures, is still a trial-error practice. In the field, different desalination materials and methods are used, sometimes with unsatisfactory results. Better understanding of the desalination process is needed in order to support the conservator with clear guidelines for choosing a suitable desalination material and method. The research presented in this paper constitutes the first step towards the development of a modular system of poultices, which can be adapted, i.e. fine-tuned to different types of substrates. Starting point is to make use of advection, i.e. the transport of salt ions with water flow. This transport mechanism is faster than diffusion and the application on immovable objects is relatively easy. In order to optimize salt extraction, a poultice working by advection should have smaller pores than the substrate. Starting from this principle the pore sizes of different desalination materials (sand, cellulose, kaolin and bentonite) mixed in different proportions, have been measured. Interesting results were obtained, showing that the desalination materials commonly used in the field are often not the most suitable ones. On the basis of the results, recipes for poultices, adapted to a specific substrate, can be formulated.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号