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   2303篇
  免费   65篇
  国内免费   2篇
教育   1845篇
科学研究   93篇
各国文化   31篇
体育   129篇
综合类   1篇
文化理论   16篇
信息传播   255篇
  2023年   13篇
  2022年   23篇
  2021年   46篇
  2020年   60篇
  2019年   84篇
  2018年   100篇
  2017年   130篇
  2016年   133篇
  2015年   79篇
  2014年   96篇
  2013年   498篇
  2012年   81篇
  2011年   86篇
  2010年   72篇
  2009年   58篇
  2008年   75篇
  2007年   80篇
  2006年   57篇
  2005年   55篇
  2004年   59篇
  2003年   44篇
  2002年   42篇
  2001年   34篇
  2000年   29篇
  1999年   25篇
  1998年   14篇
  1997年   11篇
  1996年   17篇
  1995年   13篇
  1994年   16篇
  1993年   18篇
  1992年   10篇
  1991年   7篇
  1990年   15篇
  1989年   13篇
  1988年   8篇
  1987年   17篇
  1986年   10篇
  1985年   19篇
  1984年   12篇
  1983年   11篇
  1982年   8篇
  1979年   8篇
  1978年   4篇
  1977年   4篇
  1976年   10篇
  1974年   5篇
  1885年   5篇
  1882年   4篇
  1880年   5篇
排序方式: 共有2370条查询结果,搜索用时 31 毫秒
21.
22.
Turnout, or external rotation (ER) of the lower extremities, is essential in ballet. The purpose of this study was to utilise physical examination and a biomechanical method for obtaining functional kinematic data using hip and knee joint centres to identify the relative turnout contributions from hip rotation, femoral anteversion, knee rotation, tibial torsion, and other sources. Ten female dancers received a lower extremity alignment assessment, including passive hip rotation, femoral anteversion, tibial torsion, weightbearing foot alignment, and Beighton hypermobility score. Next, turnout was assessed using plantar pressure plots and three-dimensional motion analysis; participants performed turnout to ballet first position on both a plantar pressure mat and friction-reducing discs. A retro-reflective functional marker motion capture system mapped the lower extremities and hip and knee joint centres. Mean total turnout was 129±15.7° via plantar pressure plots and 135±17.8° via kinematics. Bilateral hip ER during turnout was 49±10.2° (36% of total turnout). Bilateral knee ER during turnout was 41±5.9° (32% of total turnout). Hip ER contribution to total turnout measured kinematically was less than expected compared to other studies, where hip ER was determined without functional kinematic data. Knee ER contributed substantially more turnout than expected or previously reported. This analysis method allows precise assessment of turnout contributors.  相似文献   
23.
24.
25.
The prevalence of ischaemia-related symptoms is remarkably high among elite indoor volleyball players. Since the exposure to sport-specific demands may be higher in beach volleyball compared to indoor volleyball, the aim of this study was to assess the prevalence of ischaemia-related symptoms and associated risk factors among world-class beach volleyball players. Therefore, a questionnaire survey was performed among beach volleyball players active during the 2013 Grand Slam Beach Volleyball in the Netherlands. In total, 60 of the 128 beach volleyball players (47%) participated: 26 males and 34 females from 17 countries. The self-reported prevalence of cold or blue or pale digits in the dominant hand during or immediately after practice or competition was 38% (n = 23). Two risk factors were independently associated with symptoms of blue or pale digits: more than 14 years playing volleyball (odds ratio (OR) 4.42, 90% confidence interval (90% CI) 1.30–15.07) and sex (female) (OR 4.62, 90% CI 1.15–18.57). In conclusion, the prevalence of symptoms associated with digital ischaemia is high among international world-class beach volleyball players. Female sex and the length of the volleyball career were independently associated with an increased risk of ischaemia-related symptoms. The high prevalence of these seemingly innocuous symptoms and possible associated risk factors warrant regular monitoring since early detection can potentially prevent thromboembolic complications and irreversible tissue damage.  相似文献   
26.
This study investigated the acute endocrine responses to a 164-km road cycling event in a hot environment. Thirty-four male experienced cyclists (49.1 ± 8.3 years, 86.8 ± 12.5 kg, 178.1 ± 5.1 cm) participating in a 164-km road cycling event were recruited. Blood samples were collected within 0.3–2.0 h before the start (PRE: ~0500–0700 h) and immediately following the ride (POST). Samples were analysed for testosterone, growth hormone (GH), cortisol and interleukin-6 (IL-6). The temperature and humidity during the event were 35.3 ± 4.9°C and 47.2 ± 14.0%, respectively. Based on the finishing time, results for the fastest (FAST, 305 ± 10 min) and the slowest (SLOW, 467 ± 31 min) quartiles were compared. At POST, testosterone concentration was significantly (P < 0.05) lower (PRE, 20.8 ± 8.6; POST, 18.2 ± 6.7 nmol · L?1), while GH (PRE, 0.3 ± 0.1; POST, 2.3 ± 0.3 µg · L?1), cortisol (PRE, 661 ± 165; POST, 1073 ± 260 nmol · L?1) and IL-6 (PRE, 4.0 ± 3.4; POST, 22.4 ± 15.2 pg · mL?1) concentrations were significantly higher than those at PRE. At POST, GH and cortisol were significantly higher for the FAST group than for the SLOW group (GH, 3.6 ± 2.0 and 1.0 ± 0.8 µg · L?1; cortisol, 1187 ± 209 and 867 ± 215 nmol · L?1). Participation in an ultra-endurance road cycling event in a hot environment induced significant acute changes in concentrations of circulating hormones, with a greater augmentation of GH and cortisol in those completing the ride fastest.  相似文献   
27.

Purpose

The study evaluates how providers give patient education materials and identifies improvements to comply with Meaningful Use (MU) requirements.

Methods

Thirty-eight patient-provider interactions in two health care outpatient clinics were observed.

Results

Providers do not uniformly know MU patient education requirements. Providers have individual preferences and find gaps in what is available. Accessing and documenting patient education varies among providers. Embedded electronic health record (EHR) materials, while available, have technical access barriers.

Conclusions

Providers'' EHR skills and knowledge levels contribute to non-standardized patient education delivery.  相似文献   
28.
Governmental consultation and advice on child abuse and neglect in the Netherlands started in 1972 as a two-year experiment with four offices for "confidential doctors" in four major cities of the country. After these two experimental years, a governmental institute for prevention of child abuse and neglect was organized. Over the ensuing decade the number of offices increased to ten, covering the whole country. The State Department of Welfare, Public Health, and Environment collected data from the confidential doctors and their coworkers every year. This study compares the data of the first year 1974 with those of 1983 in order to detect changing patterns over a 10-year period. The major changes are as follows: a threefold increase in cases, an extraordinary increase in cases of emotional maltreatment, an increase in detection of child fatalities but decrease in severity of physical abuse. Sexual abuse was hardly recognized in 1974 but gradually was recognized more frequently during the study decade and accounted for an alarming 7.2% of detected cases of maltreatment in 1983. No change was found in the social conditions of the family and the identity of the perpetrators--primarily fathers and/or mothers. A decrease was noted in the percentage of married parents. The increased percentage of single parents was primarily represented by mothers alone. An increase in the numbers of victims residing at home and a decrease in the need for children's homes as a temporary or permanent residence is attributed to aftercare. The discrepancy between the results of this voluntary notification system in the Netherlands and the results of a mandatory reporting system as used in the U.S.A. is still very high. The hope is that the government will decide to make reporting of maltreatment mandatory for everyone.  相似文献   
29.
Early developmental psychologists viewed iconic representation as cognitively less complex than other forms of symbolic thought. It is therefore surprising that iconic signs are not acquired more easily than arbitrary signs by young language learners. One explanation is that children younger than 3 years have difficulty interpreting iconicity. The current study assessed hearing children's ability to interpret the meaning of iconic signs. Sixty-six 2.5- to 5-year-olds who had no previous exposure to signs were required to match iconic signs to pictures of referents. Whereas few of the 2.5-year-olds recognized the meaning of the iconic signs consistently, more than half of the 3.0-year-olds and most of 3.5-year-olds performed above chance. Thus, the ability to recognize the meaning of iconic signs gradually develops during the preschool years. Implications of these findings for sign language development, receptive signed vocabulary tests, and the development of the ability to interpret iconic symbols are discussed.  相似文献   
30.
In this study the relationships between writing instruction and functional composition performance were analyzed. The data were obtained in a national assessment on the language proficiency of students in the third year of Dutch secondary education (age ±15). Multivariate multilevel analysis showed that 10 out of 36 instructional characteristics were related to functional composition performance. The effective instructional characteristics included: instruction and exercises in writing functional texts, writing for a specific purpose, tailoring to a particular audience, global rating of writing products by the teacher, and frequent evaluation of Dutch language proficiency through teacher-made tests and written assignments. No effects were found for the rather popular subskill exercises on idiom, syntax, spelling and punctuation, and for pre-writing activities, text revisions and peer-review. Furthermore, the effect of instructional characteristics was often different on one task than on another. Finally, there was little differential effectiveness for different groups of students. If one instructional characteristic was more effective than the other, this was generally true, to an equal degree, for boys and girls and for promoted and non-promoted students.  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