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   29137篇
  免费   255篇
  国内免费   49篇
教育   20894篇
科学研究   2598篇
各国文化   291篇
体育   2188篇
综合类   50篇
文化理论   174篇
信息传播   3246篇
  2021年   316篇
  2020年   442篇
  2019年   636篇
  2018年   809篇
  2017年   849篇
  2016年   822篇
  2015年   534篇
  2014年   733篇
  2013年   5420篇
  2012年   702篇
  2011年   738篇
  2010年   648篇
  2009年   589篇
  2008年   658篇
  2007年   608篇
  2006年   615篇
  2005年   545篇
  2004年   453篇
  2003年   427篇
  2002年   383篇
  2001年   753篇
  2000年   541篇
  1999年   462篇
  1998年   264篇
  1997年   296篇
  1996年   293篇
  1995年   246篇
  1994年   281篇
  1993年   236篇
  1992年   374篇
  1991年   360篇
  1990年   400篇
  1989年   384篇
  1988年   325篇
  1987年   321篇
  1986年   338篇
  1985年   360篇
  1984年   322篇
  1983年   302篇
  1982年   247篇
  1981年   251篇
  1980年   231篇
  1979年   336篇
  1978年   277篇
  1977年   222篇
  1976年   208篇
  1975年   210篇
  1974年   193篇
  1973年   202篇
  1971年   201篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
Goethe's writings dealing with rhetorical concepts are representative of major concepts held by many Germans. His distrust of formalized, structured expression of ideas are representative of the distrust many German writers have in relationship to the study of human communication. At the same time, Goethe had to resolve this problem when he was required to offer formal instruction to actors.  相似文献   
943.
944.
945.
946.
947.
In this study, we examined the effect of creatine ingestion on muscle power output, muscle phosphocreatine resynthesis, inorganic phosphate and pH during repeated brief bouts of maximal exercise. Nine healthy males performed maximal plantar flexion before and after creatine ingestion (20 g ·day -1 for 6 days). The experimental protocol consisted of five 8 s bouts (bouts 1-5) interspersed with 30 s recovery, followed by bouts 6 (8 s) and 7 (16 s) separated by 1 and 2 min, respectively. Muscle phosphocreatine, inorganic phosphate and pH were estimated every 16 s by 31 P magnetic resonance spectroscopy. After creatine ingestion, muscle power output increased by ~5% ( P ? 0.05) from bouts 3 to 7 and muscle phosphocreatine resynthesis increased ( P ? 0.05) during 10 min recovery. The higher phosphocreatine concentration observed after only 30 s of recovery was accompanied by lower inorganic phosphate accumulation and higher pH. Strong correlations were found between exercise power restoration and the corresponding pre-exercise phosphocreatine and inorganic phosphate concentrations and muscle pH after creatine ingestion. The better maintenance of muscle power output observed after creatine ingestion was attributed to a higher rate of phosphocreatine resynthesis, lower accumulation of inorganic phosphate and higher pH.  相似文献   
948.
The aim of our study was to determine if any immediate changes in balance were discernable in college soccer players after a specially designed heading session. Eight male and two female skilled collegiate soccer players had a baseline balance pre-test using the Balance Master, followed by heading 20 balls kicked consecutively by a teammate from the touchline to a point near the goal, which was followed by a post-test using the same testing technique. Paired t-tests were used to compare balance ability between pre- and post-test conditions. There was no difference in balance pre- to post-test (85.3% and 86.2% respectively). No significant difference was noted from pre- to post-test in the mean equilibrium scores for conditions three through six on the Sensory Organization Test, with the exception of condition four, which revealed a significant increase from pre- to post-test. We concluded that an acute session of heading soccer balls may not result in balance changes in collegiate soccer players.  相似文献   
949.
Purpose: The purposes of this clinical perspective paper are (1) to expand physical therapists’ awareness to the topic of air quality as a health priority when providing professional services; and (2) to provide templates for screening the indoor clinical environments and patient profiles to avert respiratory exacerbations, especially in persons with asthma. Summary of Key Points: The location where a physical therapist practices determines the air quality indices to which a person is exposed. Poor indoor air quality can expose a person to even greater compromise of respiration (ie, Sick Building Syndrome) than outdoor air quality secondary to an array of factors like building materials, the ventilation exchange rate of an enclosed space, chemicals used in cleaning, and humidity. Statement of Conclusions: Extrinsic (ie, environmental) and intrinsic (eg, pre-disposition to airway hypersensitivity) factors must be accounted for by physical therapists to safeguard their patients and themselves from experiencing respiratory compromise and/or distress as a result of a treatment session or their place of employment. Recommendations: Efforts to screen indoor environments for potential triggers and patient risk profiles for abnormal airway reactivity should routinely be undertaken. Individualized Action Plans should be prospectively prepared and readied for implementation when warranted.Key Words: asthma, Sick Building Syndrome, indoor air quality, respiratory impairment  相似文献   
950.
通过对国家速度滑冰集训队和解放军冰上基地运动员高原训练前后肺活量、气体代谢、能量代谢、酶活性、血乳酸等生理生化指标进行测试,旨在探索高原训练对速滑运动员机体代谢水平的影响及所产生的生物学效应,为高原训练和比赛提供科学依据。研究发现,高原训练后能量代谢活跃,高原训练前后测值显示差异较大,酶活性指标改变不明显。高原训练对运动员机体产生应激作用较大,可以作为提高速滑运动员竞技能力的有效方法,在应用过程中还要根据受试者个体差异合理安排训练计划。  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