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   3757篇
  免费   67篇
  国内免费   2篇
教育   2524篇
科学研究   346篇
各国文化   26篇
体育   429篇
综合类   9篇
文化理论   27篇
信息传播   465篇
  2022年   27篇
  2021年   33篇
  2020年   59篇
  2019年   105篇
  2018年   102篇
  2017年   139篇
  2016年   127篇
  2015年   112篇
  2014年   104篇
  2013年   782篇
  2012年   90篇
  2011年   112篇
  2010年   91篇
  2009年   61篇
  2008年   84篇
  2007年   102篇
  2006年   67篇
  2005年   50篇
  2004年   64篇
  2003年   55篇
  2002年   57篇
  2001年   42篇
  2000年   73篇
  1999年   79篇
  1998年   35篇
  1997年   23篇
  1996年   31篇
  1995年   24篇
  1994年   27篇
  1993年   33篇
  1992年   37篇
  1991年   45篇
  1990年   56篇
  1989年   44篇
  1988年   45篇
  1987年   30篇
  1986年   47篇
  1985年   53篇
  1984年   47篇
  1983年   42篇
  1982年   42篇
  1981年   33篇
  1980年   28篇
  1979年   36篇
  1978年   38篇
  1977年   29篇
  1976年   23篇
  1975年   23篇
  1974年   21篇
  1968年   22篇
排序方式: 共有3826条查询结果,搜索用时 15 毫秒
971.
本文应用流式细胞术(Flow Cytometry,FCM)检测了102例石蜡包埋的乳癌组织的细胞核DNA含量,并探讨了DNA指数(DNA Index.DI)和S期细胞比例(S-phase Fraction,SPF)与临床预后因素及病人术后生存状况的关系。结果显示:16例为DNA二倍体,8例近二倍体,78例(77%)非整倍体。非整倍体癌较二倍体/近二倍体癌的SPF高。DI值与组织学分级、淋巴结状况、原发肿瘤大小和临床分期密切相关,而与病人诊断时的年龄无关。淋巴结转移阳性组较阴性组、晚期肿瘤(Ⅲ、Ⅳ期)比早期肿瘤(Ⅰ、Ⅱ期)的DI值高(P<0.05),而非整倍体率仅有降低的趋势但无显著性差异,说明DI值作为一个预后参数比倍性分析统计效率高。SPF与病人的各预后因素及生存情况无明显关系。二倍体/近二倍体癌病人较非整倍体癌病人的生存率高、无瘤生存时间长,说明流式细胞术DNA含量测定确实可为乳癌病人的预后提供有价值的信息。  相似文献   
972.
Improvements in running economy (RE) are thought to lead to improvements in running performance (P). Multiple interventions have been designed with the aim of improving RE in middle and long-distance runners. The aim of this study was to assess the effect of interventions of at least 2-weeks’ duration on RE and P and to determine whether there is a relationship between changes in RE (ΔRE) and changes in running performance (ΔP). A database search was carried out in Web of Science, Scopus and SPORTDiscus. In accordance with a PRISMA checklist 10 studies reporting 12 comparisons between interventions and controls were included in the review. There was no correlation between percentage ΔRE and percentage ΔP (r = 0.46, P = 0.936, 12 comparisons). There was a low risk of reporting bias but an unclear risk of bias for other items. Meta-analyses found no statistically significant differences between interventions and controls for RE (SMD (95% CI) = ?0.37 (?1.43, 0.69), 204 participants, p = 0.49) or for P (SMD (95% CI) = ?0.65 (?26.02, 24.72, 204 participants, p = 0.99). There is a need for studies of greater statistical power, methodological quality, duration and homogeneity of intervention and population. Standardised measures of performance and greater control over non-intervention training are also required.  相似文献   
973.
Williams  Logan D. A.  Woodson  Thomas S. 《Minerva》2019,57(4):453-477

Socio-technical governance has been of long-standing interest to science and technology studies and science policy studies. Recent calls for midstream modulation direct attention to a more complicated model of innovation, and a new place for social scientists to intervene in research, design and development. This paper develops and expands this earlier work to demonstrate how a suite of concepts from science and technology studies and innovation studies can be used as a heuristic tool to conduct real-time evaluation and reflection during the process of innovation – upstream, midstream, and downstream. The result of this new protocol is inclusivity mainstreaming: determining if and how marginalized peoples and perspectives are being maximally incorporated into the model of innovation, while highlighting common problems of inequality that need to be addressed.

  相似文献   
974.
975.
What players should eat on match day is a frequently asked question in sports nutrition. The recommendation from the available evidence is that players should eat a high-carbohydrate meal about 3 h before the match. This may be breakfast when the matches are played around midday, lunch for late afternoon matches, and an early dinner when matches are played late in the evening. The combination of a high-carbohydrate pre-match meal and a sports drink, ingested during the match, results in a greater exercise capacity than a high-carbohydrate meal alone. There is evidence to suggest that there are benefits to a pre-match meal that is composed of low-glycaemic index (GI) carbohydrate foods rather than high-GI foods. A low-GI pre-match meal results in feelings of satiety for longer and produces a more stable blood glucose concentration than after a high-GI meal. There are also some reports of improved endurance capacity after low-GI carbohydrate pre-exercise meals. The physical demands of soccer training and match-play draw heavily on players' carbohydrate stores and so the benefits of good nutritional practices for performance and health should be an essential part of the education of players, coaches, and in particular the parents of young players.  相似文献   
976.
The first purpose of this study was to determine a possible explanation for the variability in the response to eccentric exercise by having participants repeat the same exercise 1 year apart. The second purpose was to examine whether initial injury in response to eccentric exercise was associated with the extent of the repeated bout effect (RBE). Male students performed 30 eccentric contractions (ECC) of the elbow flexors using a dumbbell set at 80% of the pre-exercise maximal isometric force (MIF). Participants were then classified into low (LR; n=6), medium (MR; n=6), high (HR; n=5), and higher (HrR; n=7) based on the increase in blood creatine kinase (CK) activity. A year later, participants repeated this exercise (ECC30). Four days after ECC30, participants performed 70 eccentric contractions (ECC70). Range of motion, MFI upper arm circumference, soreness, and blood CK activity were measured before and up to 9 days after each bout. The change in the criterion measures following ECC and ECC30 were similar for each group. There were no further changes in all parameters after ECC70 for MR, HR, and HrR, although there was a small increase in CK after ECC70 for LR. LR showed a smaller RBE after ECC70 compared with the other groups. It is concluded that participants who exercised 1 year apart showed remarkably similar responses between the bouts. The extent of the RBE following the second bout for the LR group is less for participants who demonstrate the least evidence of muscle damage after a first exercise bout.  相似文献   
977.
The aim of this study was to understand changes in technique within an athlete's own performance during a sprint hurdles run. Four athletes performed a training session containing four trials each over 10 hurdles. Clearances at hurdles three and nine were videotaped from a side view and manually digitised. All athletes in this study yielded a lower running speed over the hurdle at the ninth hurdle in comparison to the third hurdle in each run. All athletes also showed further signs of potential tiredness in the clearances of the ninth hurdle. Interestingly, these changes in technique varied among the athletes. This poses challenges to coaches, as they need to evaluate individually what changes in training should be introduced to keep the quality of clearances as high as possible throughout training. To match more closely the velocities to those in competitions, consideration could be given in training to shorten gradually the distances between the hurdles more during the latter part of the run, although this should be individually checked, based on the athlete. This way, athletes could learn to clear the hurdle with a higher horizontal velocity, even when fatigue is potentially influencing the performance.  相似文献   
978.
979.
The purpose of the study was to develop a valid and reliable tool for use in assessing motor skills in preschool children in field based settings. The development of the CHAMPS (Children's Activity and Movement in Preschool Study) Motor Skills Protocol (CMSP) included evidence of its reliability and validity for use in field-based environments as part of large epidemiological studies. Following pilot work, 297 children (3-5 years old) from 22 preschools were tested using the final version of the CMSP and the TGMD-2. Reliability of the CMSP and interobserver reliability were determined using intraclass correlation procedures (ICC; ANOVA). Concurrent validity was assessed using Pearson correlation coefficients to compare the CMSP to the original Test of Gross Motor Development (2(nd) Edition) (TGMD-2). Results indicated that test reliability, interobserver reliability and validity coefficients were all high, generally above R/r = 0.90. Significant age differences were found. Outcomes indicate that the CMSP is an appropriate tool for assessing motor development of 3-, 4-, and 5-year-old children in field-based settings that are consistent with large-scale trials.  相似文献   
980.
We provide an overview of some of the outstanding papers published in the Journal over the last 25 years within the discipline of psychology. Altogether, almost 300 papers had been published in the Journal under the psychology banner at the start of its silver anniversary year. The greatest contribution of papers has come from the motor control and learning and sport psychology sub-areas, with papers focusing on exercise psychology being a more recent addition. Prominent research themes that have emerged from each of the different sub-areas are reviewed and some notable omissions highlighted. Finally, some issues for sport and exercise psychologists to consider in coming years are briefly highlighted.  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