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   1139篇
  免费   15篇
  国内免费   9篇
教育   621篇
科学研究   138篇
各国文化   15篇
体育   224篇
综合类   13篇
文化理论   1篇
信息传播   151篇
  2024年   6篇
  2022年   7篇
  2016年   5篇
  2015年   6篇
  2014年   18篇
  2013年   14篇
  2012年   85篇
  2011年   96篇
  2010年   33篇
  2009年   13篇
  2008年   63篇
  2007年   72篇
  2006年   72篇
  2005年   58篇
  2004年   51篇
  2003年   57篇
  2002年   43篇
  2001年   35篇
  2000年   36篇
  1999年   16篇
  1998年   6篇
  1997年   7篇
  1996年   6篇
  1995年   14篇
  1994年   11篇
  1993年   13篇
  1992年   18篇
  1991年   18篇
  1990年   19篇
  1989年   18篇
  1988年   15篇
  1987年   24篇
  1986年   26篇
  1985年   17篇
  1984年   9篇
  1983年   18篇
  1982年   12篇
  1981年   12篇
  1980年   9篇
  1979年   8篇
  1978年   4篇
  1959年   6篇
  1957年   4篇
  1956年   5篇
  1955年   3篇
  1954年   6篇
  1953年   5篇
  1951年   3篇
  1948年   8篇
  1947年   3篇
排序方式: 共有1163条查询结果,搜索用时 15 毫秒
41.
The purpose of this study was to improve understanding of the link between self-presentational concerns and competitive anxiety. Specifically, we examined (a) associations among self-presentational concerns and competitive state anxiety dimensional symptom responses using the modified Competitive State Anxiety Inventory-2 (CSAI-2; Martens, Vealey, & Burton, 1990) and (b) whether self-presentational concerns mediate trait-state anxiety relationships. In addressing these matters, we also examined the factor structure and composition of the Self-Presentation in Sport Questionnaire (SPSQ; Wilson & Eklund, 1998). Results showed that self-presentational concerns were positively associated with intensity and frequency dimensional symptoms and negatively associated with direction symptoms. Results also showed that self-presentational concerns demonstrated consistently higher associations with the cognitive component and the intensity symptom of the CSAI-2 state measures. Results showed no support for the notion that self-presentational concerns mediate the trait-state anxiety relationship. When examining the factor structure and composition of the SPSQ, the results from two independent athlete samples support the tenability of an abbreviated 21-item four-factor model. Thus the newly constituted scale is recommended for measuring self-presentational concerns in sport.  相似文献   
42.
Although angiogenetic therapy using recombinant growth factors holds much hope for the treatment of ischaemic diseases, there are still many unanswered questions, including the method of administration, the correct dose of these factors, and the duration of the therapeutic approach. Exercise has also been suggested to induce neovascularizaiton in muscles. We evaluated the angiogenetic effects of the intramuscular administration of basic-fibroblast growth factor (b-FGF) and acidic-fibroblast growth factor (a-FGF) in rat heart, compared with rats who exercised daily. In conclusion, both the intramuscular administration of b-FGF and exercise increased significantly angiogenesis in the heart in contrast to the intramuscular administration of a-FGF, which was ineffective.  相似文献   
43.
The aims of this study were to examine the changes in plasma concentrations of inflammatory cytokines induced by training and competition in professional cyclists. We report the serum concentrations of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-a), tumour necrosis factor receptors I and II (TNFR-I and -II) in a prospective, randomized, double-blind trial involving the administration of AM3 (Inmunoferon), an oral booster immunomodulator, or placebo to 16 professional cyclists (n = 8 in each group) for 65 consecutive days. Serum was collected just before treatment began (baseline), at the end of pre-competition training, before the mountain stage of the competition (60 days), 4 h after finishing this stage (62 days), and 18 h after the fifth and last day of competition (65 days). To determine the normal levels of cytokines and soluble TNF receptors, individual samples from 14 moderately trained healthy controls were studied. After 60 days of training, the serum concentrations of IL-6 did not differ significantly from those at the beginning of the study for either group of cyclists (placebo and AM3). A significant rise was seen in IL-6 concentrations in both the AM3 and placebo groups at 62 days, 4 h after finishing the mountain stage. The increase was significantly greater in the placebo group than in the AM3 group. At 65 days of treatment, 18 h after the fifth and last day of competition, IL-6 concentrations were similar to those recorded at the end of the training, but were significantly higher in the placebo group than in the AM3 group. At the end of training, serum TNFR-I concentrations in both groups of cyclists were significantly lower than at baseline. The concentrations of serum TNFR-I and -II both 4 h after finishing the mountain stage and 18 h after the fifth and last day of competition were significantly higher than those recorded after training in both groups. Professional cycling competition is associated with increases in serum IL-6 and TNFR-I and -II concentrations. Inmunoferon treatment reduced significantly the concentrations of IL-6 but not those of TNFR-I and -II.  相似文献   
44.
第二课教師在問課之後,便轉到農民戰争第二階段的史實。太平天國的上層統治階級蜕化了。在残殺楊秀清之後,隨着便出现一個由高級官僚組成的新封建階級。軍事将領和負責管理地産的官吏们奪取了土地後,自己變成地主。‘人民大衆失去對自己領袖的信心,——中國的歷史家寫道——因而閃避他们’(参閥r、c、卡拉——莫爾查教授著的‘太平軍’。莫斯科,一九五○版,第一。八頁)。r、E、葉非莫夫在插寫一八五六年政變後太平天國的情形的時候,指出了‘人民的、反封建性質的運動和脫離人民的太平軍的領導政策之間的差別,越來越大了’(‘中國近代史概要’一九五一年第二版,第六一頁)。  相似文献   
45.
兒童到了七歲年齡,在生理和心理上已經具備實施有系統的學校教育所必需的基本條件。這些就是神經系統比較堅固,神經疲勞程度比較早幾年減少,由此使兒童可以省去午睡,還有就是注意能力比較過去更为耐久。七歲兒童所達到的智力發展程度,和所積累的相當多的經驗,已使他能有基本的邏輯來討論問題,能對許多不複雜的現象作分析和  相似文献   
46.
ThetoleranceofthemudskipperBoleophthalmusboddaertitocyanideishigherthanthoseofotherfishes[1].Suchahightolerancetocyanidedoesnotinvoveareductionofmetabolicrateoranenhancedanaerobicmetabolism,oracyanide-insensitiverespiratorypathway.Instead,itisaresultofthepresenceofasurplusofcytochromeoxidaseandinduciblecyanide-detoxifyingmechanisms,tumingcyanideinthiocyanate,inthismudskipper[1].ThoughCN-isdetoxifiedtoSCN-,realizingbiomembranesaremorepermeabletoHCNthanCN-,wedecidedtoinvestigateiftheprotondi…  相似文献   
47.
48.
49.
Electrocortical and behavioral responses of low, moderate, and high physically active older adults were compared with a younger control group on neutral and incompatible conditions of a flankers task. Compared to younger adults, high and moderate active older adults exhibited increased event-related potentials component P3 amplitude for the incompatible condition at the frontal electrode site. For the neutral condition, only low active older adults exhibited decreased amplitude at the central-parietal site, compared to younger adults. P3 latency revealed the longest latencies for low active older adults, followed by moderate active, high active, and younger adults, respectively. Reaction time (RT) data revealed that younger adults exhibited faster RT compared to all three older groups. Results suggest that physical activity may improve executive control function in older adults by affecting the distribution of P3 amplitude, which has been related to memory and attentional processes, and by decreasing P3 latency, which relates to the speed of cognitive processing.  相似文献   
50.
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