全文获取类型
收费全文 | 88335篇 |
免费 | 1726篇 |
国内免费 | 1374篇 |
专业分类
教育 | 51023篇 |
科学研究 | 12680篇 |
各国文化 | 159篇 |
体育 | 4000篇 |
综合类 | 4083篇 |
文化理论 | 44篇 |
信息传播 | 19446篇 |
出版年
2024年 | 37篇 |
2023年 | 249篇 |
2022年 | 817篇 |
2021年 | 1395篇 |
2020年 | 1745篇 |
2019年 | 1316篇 |
2018年 | 985篇 |
2017年 | 1120篇 |
2016年 | 1294篇 |
2015年 | 1916篇 |
2014年 | 5128篇 |
2013年 | 6371篇 |
2012年 | 6864篇 |
2011年 | 7423篇 |
2010年 | 5181篇 |
2009年 | 4844篇 |
2008年 | 5674篇 |
2007年 | 6851篇 |
2006年 | 6995篇 |
2005年 | 6270篇 |
2004年 | 5020篇 |
2003年 | 4394篇 |
2002年 | 3332篇 |
2001年 | 2692篇 |
2000年 | 1491篇 |
1999年 | 596篇 |
1998年 | 368篇 |
1997年 | 298篇 |
1996年 | 229篇 |
1995年 | 127篇 |
1994年 | 96篇 |
1993年 | 87篇 |
1992年 | 80篇 |
1991年 | 32篇 |
1990年 | 24篇 |
1989年 | 11篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 1篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 10篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1957年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
This editorial paper presents 11 papers related to the special issue proposed by UNICEF on the Education Response to COVID-19. The COVID-19 pandemic provoked an education emergency of unprecedented scale. At its onset in February 2020, school closures were announced in the worst-hit countries. At the peak of the crisis, 90 per cent of learners worldwide had had their education disrupted. Some learners, especially those from the most marginalised population groups, were put at risk of permanent dropout, provoking long-term and significant negative effects on children’s life-long wellbeing and the socio-economic development of their communities and countries. This special issue, which received contributions from UNICEF staff and various researchers, focuses on the impact of school closures, the effectiveness of remote learning solutions, equity implications, the mitigation of learning loss and notions around re-opening better. Different research perspectives and evidence is gathered to help strengthen policy considerations and future planning. The conclusion emphasizes building on the innovative solutions generated by the response to the crisis to make education systems more resilient, whilst also reinforcing the focus on equity and inclusion so that pre-existing disparities are not exacerbated in the future. 相似文献
2.
《Information processing & management》2023,60(3):103262
Smart wheelchairs based on brain–computer interface (BCI) have been widely utilized recently to address certain mobility problems for people with disability. In this paper, we present SmartRolling, an intuitive human–machine interaction approach for the direct control of robotic wheelchair that jointly leverages EEG signals and motion sensing techniques. Specifically, SmartRolling offers two wheelchair-actuation modes for users with different physical conditions: (1) head motion only — people who are severely disabled but able to do basic tasks using eyes and head, and (2) head and hands motion — in addition to type 1, people who can use functioning hands/arms for extra tasks. The system issues operation commands by recognizing different EEG patterns elicited by motor execution (ME) tasks including eye blink, jaw clench, and fist open/close, while at the same time estimates users’ steering intentions based on their facing direction by leveraging inertial measurements and computer vision techniques. The experiment results demonstrate that the proposed system is robust and effective to meets the individual’s needs and has great potential to promote better health. 相似文献
3.
ABSTRACTThis article suggests that situations in which multiple research teams are convened under similar conditions present an opportunity to discover factors that lead to productive collaboration. It argues that social network analysis of research team outputs becomes more valuable when paired with data about research participant perceptions; and that any variables used as indicators of collaboration need to be calibrated using datasets from multiple studies with cross-team comparisons. The article provides an example of the kind of methodology needed to achieve this, describing a study with data from four research teams based at an Australian university campus, reporting their research performance over four years under conditions in which many variables were controlled and with results augmented by a survey of participant perceptions. Findings from the study indicate that there were exceptions to hypothesized associations between participant perceptions of collaboration and specific social network analysis measures over co-authorship data. The article suggests that, given the methodological challenges of studying research teams in the field, multiple datasets combining findings such as those in the present study are a path towards the development of indicators of productive higher education research collaboration. 相似文献
4.
This study investigated the effect of including explicit nature of science (NOS) content in read-alouds of elementary science trade books on the teaching and learning of NOS. We focused on three aspects of NOS: the creative, the empirical, and the inferential NOS. The trade books were read aloud by teachers in three hierarchical levels: Level I served as a control and consisted of a trade book that remained unmodified, Level II consisted of a trade book that had been modified to include explicit references to NOS, and Level III consisted of a modified trade book accompanied by educative curriculum materials that were aimed at improving the teachers' views of NOS as well as supporting teaching about NOS. We used the Views of Nature of Science Questionnaire-form CE (VNOS-CE) preintervention and postintervention to determine changes in teachers' views of NOS and interviews preintervention and postintervention to determine changes in students' views. Audio recordings of read-alouds were used to determine changes in teaching practice, including the frequency and the quality (i.e., naïve or informed) of the NOS references in the discussions. Interviews were used to determine teachers' perceptions of the modified trade books and educative curriculum materials. We found that both teachers and students developed more informed views of the targeted NOS aspects after the intervention and that teachers addressed NOS more often, and in a more informed manner, when they had trade books that explicitly supported NOS instruction and educative curriculum materials that supported their learning about NOS. Furthermore, they perceived the intervention materials favorably. Teachers' views and practices were able to change in tandem because of the intervention materials that supported explicit NOS instruction. We highlight the need for more widespread development of similar educative curriculum materials. 相似文献
5.
6.
Terese L. Chmielewski Justin Tatman Shuhei Suzuki MaryBeth Horodyski Darcy S. Reisman Russell M. Bauer James R. Clugston Daniel C. Herman 《运动与健康科学(英文)》2021,10(2):154
This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion (SRC) to increased risk for musculoskeletal injury. Multiple studies have found that athletes who are post-SRC have higher risk for musculoskeletal injury compared to their counterparts. A small body of research suggests that impairments in motor control are associated with musculoskeletal injury risk. Motor control involves the perception and processing of sensory information and subsequent coordination of motor output within the central nervous system to perform a motor task. Motor control is inclusive of motor planning and motor learning. If sensory information is not accurately perceived or there is interference with sensory information processing and cognition, motor function will be altered, and an athlete may become vulnerable to injury during sport participation. Athletes with SRC show neuroanatomic and neurophysiological changes relevant to motor control even after meeting return to sport criteria, including a normal neurological examination, resolution of symptoms, and return to baseline function on traditional concussion testing. In conjunction, altered motor function is demonstrated after SRC in muscle activation and force production, movement patterns, balance/postural stability, and motor task performance, especially performance of a motor task paired with a cognitive task (i.e., dual-task condition). The clinical implications of this conceptual framework include a need to intentionally address motor control impairments after SRC to mitigate musculoskeletal injury risk and to monitor motor control as the athlete progresses through the return to sport continuum. 相似文献
7.
Education Preparation Programs (EPPs) are increasingly pressured to demonstrate alignment between program supports and candidates’ outcomes. Using mixed methods, we studied the Early Field Immersion School (EFIS), an effort to improve candidates’ early field experiences. Participants included 171 candidates enrolled in a graduate certificate program and 11 university-based faculty. EFIS candidates spent increased time in early field experiences, yet EFIS was not associated with candidates’ performance at program exit. Although we found that while candidates and faculty alike valued EFIS supports, participation was negatively associated with perceptions of preparedness. We discuss these discrepancies and offer suggestions for ongoing research. 相似文献
8.
[目的/意义]面向“十四五”的高校图书馆文献信息资源建设既是整体规划的重要组成部分,又是图书馆的服务保障与基础条件。明确编制过程、调研重点、发展思路与实施措施,对于高校图书馆中长期的文献信息资源建设战略有重要的指导作用和现实意义。[方法/过程]结合文献调研与行业观察和分析,采取案例研究、政策文本解读、比较研究等方法,总结高校图书馆制订文献信息资源建设“十四五”规划的策略与发展思路。[结果/结论]文献信息资源建设的总体思路是赋能存量、做优增量和把握变量,针对新发展阶段高校图书馆的目标与任务,提出具体的实施策略。 相似文献
9.
Benjamin K. Williams Ross H. Sanders Joong Hyun Ryu Philip Graham-Smith Peter J. Sinclair 《Journal of sports sciences》2020,38(10):1115-1123
ABSTRACT To maintain the accuracy of squash shots under varying conditions, such as the oncoming ball’s velocity and trajectory, players must adjust their technique. Although differences in technique between skilled and less-skilled players have been studied, it is not yet understood how players vary their technique in a functional manner to maintain accuracy under varying conditions. This study compared 3-dimensional joint and racket kinematics and their variability between accurate and inaccurate squash forehand drives of 9 highly skilled and 9 less-skilled male athletes. During inaccurate shots, less-skilled players hit the ball with a more open racket, demonstrating a difference in this task-relevant parameter. No joint kinematic differences were found for accuracy for either group. Coordinated joint rotations at the elbow and wrist both displayed a “zeroing-in” effect, whereby movement variability was reduced from the initiation of propulsive joint rotation to a higher consistency at ball-impact; potentially highlighting the “functionality” of the variability prior to the impact that enabled consistent task-relevant parameters (racket orientation and velocity) under varying conditions. Further, highly skilled players demonstrated greater consistency of task-relevant parameters at impact than less-skilled players. These findings highlight the superior ability of highly skilled players to adjust their technique to achieve consistent task-relevant parameters and a successful shot. 相似文献
10.
Fadhaa A. Ghafil Bassim I. Mohammad Hussain S. Al-Janabi Najah R. Hadi Hayder A. Al-Aubaidy 《Indian journal of clinical biochemistry : IJCB》2021,36(1):81
Genetic variation in the angiotensin II type 1 receptor (AT1R) has an important effect on the outcome of acute coronary syndrome (ACS) initiated treatment with captopril. This study aims to investigate the impact of genetic polymorphism of AT1R (rs5186 and rs275651) on the ACS outcome in Iraqi patients treated with captopril. A total of 250 Iraqi individuals with ACS were included in this case—control study and they were divided into two study groups; Study group 1 included 125 participants who were prescribed captopril, 25 mg twice daily and study group 2 included 125 participants who received no captopril as part of their ACS treatment (control study). The AT1R gene (rs5186) CC genotype was found to be associated with ST-elevation myocardial infarction (STEMI) (Odd’s ratio (O.R) = 1.2, P = 0.7), while AC was associated with Non-ST-elevation myocardial infarction (NSTEMI) and unstable angina (UA) (O.R = 1.2, P = 0.8). AC genotype is more prone to have Percutaneous coronary intervention (PCI) after ACS attack (O.R = 1.2, P = 0.6). CC genotype had a risk to get less improvement (O.R = 1.6, P = 0.5), so might require higher doses of captopril during acute coronary insult. The AT1R gene (rs275651) AA genotype was associated with UA (O.R = 1.3, P = 0.9). AA and AT genotypes were more prone to have PCI after ACS attack (O.R = 3.9 P = 0.2, O.R = 3.5, P = 0.3 respectively) and thus requiring higher doses of captopril. We conclude that the AT1R rs5186, rs275651 genetic polymorphisms might partially affect the clinical outcome of ACS patients treated with captopril and might have captopril resistance which requires higher doses. 相似文献