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   4502篇
  免费   71篇
  国内免费   46篇
教育   3040篇
科学研究   404篇
各国文化   37篇
体育   528篇
综合类   87篇
文化理论   83篇
信息传播   440篇
  2023年   26篇
  2022年   70篇
  2021年   123篇
  2020年   173篇
  2019年   252篇
  2018年   271篇
  2017年   279篇
  2016年   225篇
  2015年   188篇
  2014年   190篇
  2013年   754篇
  2012年   204篇
  2011年   205篇
  2010年   181篇
  2009年   144篇
  2008年   110篇
  2007年   174篇
  2006年   158篇
  2005年   105篇
  2004年   89篇
  2003年   104篇
  2002年   96篇
  2001年   69篇
  2000年   58篇
  1999年   45篇
  1998年   28篇
  1997年   24篇
  1996年   31篇
  1995年   24篇
  1994年   23篇
  1993年   15篇
  1992年   16篇
  1991年   16篇
  1990年   15篇
  1989年   8篇
  1988年   10篇
  1987年   14篇
  1986年   13篇
  1985年   10篇
  1984年   4篇
  1982年   5篇
  1981年   8篇
  1980年   4篇
  1979年   7篇
  1978年   8篇
  1977年   6篇
  1976年   7篇
  1973年   4篇
  1970年   4篇
  1963年   3篇
排序方式: 共有4619条查询结果,搜索用时 15 毫秒
51.
电影<芙蓉镇>是在同名小说的基础上通过宏大的历史叙事关照人性和人情,对人的历史进行了更深入的探询.影片把人物放在尖锐环境中去写,多侧面、立体化地展示生活中的小人物,塑造典型环境中的典型形象,再现一个时代,还原历史的真实.影片深刻揭示了人物从人性的压抑到生命的搏斗这一动人心魄的历史.  相似文献   
52.
采用正交试验设计研究捕收剂用量、起泡剂用量和矿浆浓度对浮选的影响。结果发现当起泡剂用量为1000g/t,起泡剂为120g/t,矿浆浓度为60g/L时,精煤产率最高,为82.88%。  相似文献   
53.
The aim of this study was to examine spatiotemporal characteristics and joint angles during forward and backward walking in water at low and high stride frequency. Eight healthy adults (22.1 ± 1.1 years) walked forward and backward underwater at low (50 pulses) and high frequency (80 pulses) at the xiphoid process level with arms crossed at the chest. The main differences observed were that the participants presented a greater speed (0.58 vs. 0.85 m/s) and more asymmetry of the step length (1.24 vs. 1.48) at high frequency whilst the stride and step length (0.84 vs. 0.7 m and 0.43 vs. 0.35 m, respectively) were lower compared to low frequency (P < 0.05). Support phase duration was higher at forward walking than backward walking (61.2 vs. 59.0%). At initial contact, we showed that during forward walking, the ankle and hip presented more flexion than during backward walking (ankle: 84.0 vs. 91.8º and hip: 22.8 vs. 8.0º; P < 0.001). At final stance, the knee and hip were more flexed at low frequency than at high frequency (knee: 150.0 vs. 157.0º and hip: ?12.2 vs. –14.5º; P < 0.001). The knee angle showed more flexion at forward walking (134.0º) than backward walking (173.1º) (P < 0.001). In conclusion, these results show how forward and backward walking in water at different frequencies differ and contribute to a better understanding of this activity in training and rehabilitation.  相似文献   
54.
55.
The aim of this study was to quantify the type of offensive sequences that result in goals in elite futsal. Thirty competitive games in the Spanish Primera Division de Sala were analysed using computerised notation analysis for patterns of play that resulted in goals. More goals were scored in positional attack (42%) and from set pieces (27%) compared to other activities. The number of defence to offense “transitions” (= 45) and the start of offensive plays due to the rules of the game (= 45) were the most common type of sequences that resulted in goals compared to other patterns of play. The central offensive zonal areas were the most common for shots on goal, with 73% of all goals scored from these areas of the pitch compared to defensive and wide zones. The foot was the main part of the body involved in scoring (= 114). T-pattern analysis of offensive sequences revealed regular patterns of play, which are common in goal scoring opportunities in futsal and are typical movement patterns in this sport. The data demonstrate common offensive sequences and movement patterns related to goals in elite futsal and this could provide important information for the development of physical and technical training drills that replicate important game situations.  相似文献   
56.
This study aimed to verify the prevalence and characteristics of sports injuries (SI) and determine the association between the physical activity level (PA) and SI with perception of health-related quality of life (HRQoL) in Brazilian basketball master athletes. A cross-sectional study was conducted with 410 male master athletes, between 35 and 85 years of age (mean 52.26, SD ±11.83). The HRQoL was assessed using the Medical Outcomes Study – Short Form-36. The PA was evaluated using the International Physical Activity Questionnaire. Information regarding SI was collected using the Reported Morbidity Survey. Poisson regression, as estimated by the prevalence ratio (PR), was used as a measure of the association of PA and SI with HRQoL. The majority of athletes showed a high SI prevalence (58.3%) and reported one injury (67.8%) that occurred during training (61.1%) and primarily affected a lower limb (74.6%). The adjusted regression models showed a positive association of PA with the Functional Capacity (PR = 1.46, 95% confidence interval [CI] = 1.12–1.90) and Physical Component (PR = 1.32, 95% CI = 1.03–1.70) of HRQoL. Furthermore, the SI were negatively associated with HRQoL in Functional Capacity (PR = 1.85, 95% CI = 1.51–2.27), Physical Aspects (PR = 3.99, 95% CI = 3.08–5.18), Pain (PR = 1.65, 95% CI = 1.26–2.16), Social Functioning (PR = 1.79, 95% CI = 1.41–2.27), Emotional Aspects (PR = 4.40, 95% CI = 3.35–5.78), Mental Health domains (PR = 1.37, 95% CI = 1.06–1.68), Physical Component (PR = 2.35, 95% CI = 1.90–2.90) and Mental Component (PR = 2.65, 95% CI = 2.14–3.29). These results highlighted that master athletes showed a high SI prevalence, primarily in the lower limbs. PA positively correlates with the physical HRQoL domain, whereas SI may decrease the HRQoL levels of both physical and mental domains.  相似文献   
57.
The analysis of the joint kinematics during swimming plays a fundamental role both in sports conditioning and in clinical contexts. Contrary to the traditional video analysis, wearable inertial-magnetic measurements units (IMMUs) allow to analyse both the underwater and aerial phases of the swimming stroke over the whole length of the swimming pool. Furthermore, the rapid calibration and short data processing required by IMMUs provide coaches and athletes with an immediate feedback on swimming kinematics during training. This study aimed to develop a protocol to assess the three-dimensional kinematics of the upper limbs during swimming using IMMUs. Kinematics were evaluated during simulated dry-land swimming trials performed in the laboratory by eight swimmers. A stereo-photogrammetric system was used as the gold standard. The results showed high coefficient of multiple correlation (CMC) values, with median (first–third quartile) of 0.97 (0.93–0.95) and 0.99 (0.97–0.99) for simulated front-crawl and breaststroke, respectively. Furthermore, the joint angles were estimated with an accuracy increasing from distal to proximal joints, with wrist indices showing median CMC values always higher than 0.90. The present findings represent an important step towards the practical use of technology based on IMMUs for the kinematic analysis of swimming in applied contexts.  相似文献   
58.
The objective of the present study was to investigate the effects of combined training without caloric restriction on inflammatory markers in overweight girls. Thirty-three girls (13–17 years) were assigned into overweight training (n = 17) or overweight control (n = 16) groups. Additionally, a normal-weight group (n = 15) was used as control for the baseline values. The combined training programme consisted of six resistance exercises (three sets of 6–10 repetitions at 60–70% 1 RM) followed by 30 min of aerobic exercise (walking/running) at 50–80% VO2peak, performed in the same 60 min session, 3 days/weeks, for 12 weeks. Body composition, dietary intake, aerobic fitness (VO2peak), muscular strength (1 RM), glycaemia, insulinemia, lipid profile and inflammatory markers (C-reactive protein, interleukin-6, tumour necrosis factor-alpha, interleukin-10, leptin, resistin and adiponectin) were measured before and after intervention. There was a significant decrease in body fat (< 0.01) and increase in fat-free mass (< 0.01), VO2peak (< 0.01), 1 RM for leg press (< 0.01) and bench press (< 0.01) in the overweight training group. Concomitantly, this group presented significant decreases in serum concentrations of C-reactive protein (< 0.05) and leptin (< 0.05), as well as in insulin resistance (< 0.05) after the experimental period. In conclusion, 12 weeks of combined training without caloric restriction reduced inflammatory markers associated with obesity in overweight girls.  相似文献   
59.
The aim of this study was to identify the dynamics of tactical behaviour emerging on different timescales in football small-sided games and to quantify short- and long-term exploratory behaviour according to the number of opponents. Two teams of four professional male footballers played small-sided games against two different teams with a variable number of opponents (3, 5 and 7). Data were collected using a combination of systematic observation and a non-differential global positioning system (15 Hz). The temporal diversity and structural flexibility of the players were determined by calculating the dynamic overlap order parameter q, entropy and trapping strength. Analysis of the exploratory dynamics revealed two different timescales, forming a different metastable landscape of action for each constraint. Fast dynamics lasted on average a few seconds and consisted of changes in tactical patterns. The long timescale corresponded to the shared tasks of offence and defence lasting tens of seconds. The players’ tactical diversity decreased with an increasing number of opponents, especially in defence. Manipulating numerical imbalance is likely to promote changes in the diversity, unpredictability and flexibility of tactical solutions. The fact that the temporally nested structure of constraints shaped the emergence of tactical behaviour provides a new rationale for practice task design. The manipulation of numerical imbalance on the timescale of a few tens of seconds, on which the exploratory behaviour of players saturates, may help coaches to optimise the exploratory efficiency of the small-sided games.  相似文献   
60.
以德治国的关键是以德治党.共产党员是我国现代化建设的骨干力量,必须努力提高自身素质,加强自身修养,力求做到德才兼备,成为群众学习的楷模.而要达到这一标准,其最基本的途径是学习理论.该论文集中阐述了刘少奇同志论共产党员理论修养的重要思想,目的在于说明理论修养是共产党员的立身之本.  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