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   1228篇
  免费   24篇
教育   757篇
科学研究   45篇
各国文化   28篇
体育   237篇
文化理论   14篇
信息传播   171篇
  2024年   1篇
  2023年   11篇
  2022年   10篇
  2021年   18篇
  2020年   43篇
  2019年   51篇
  2018年   105篇
  2017年   104篇
  2016年   91篇
  2015年   57篇
  2014年   51篇
  2013年   327篇
  2012年   57篇
  2011年   47篇
  2010年   28篇
  2009年   35篇
  2008年   31篇
  2007年   34篇
  2006年   26篇
  2005年   17篇
  2004年   20篇
  2003年   16篇
  2002年   14篇
  2001年   6篇
  2000年   2篇
  1999年   3篇
  1998年   5篇
  1997年   8篇
  1996年   3篇
  1995年   4篇
  1994年   2篇
  1993年   4篇
  1992年   2篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1982年   2篇
  1981年   1篇
  1980年   3篇
  1978年   1篇
  1973年   1篇
  1972年   1篇
  1966年   1篇
  1947年   1篇
  1935年   1篇
排序方式: 共有1252条查询结果,搜索用时 0 毫秒
41.
ABSTRACT

Background and Context: Current introductory instruction fails to identify, structure, and sequence the many skills involved in programming.

Objective: We proposed a theory which identifies four distinct skills that novices learn incrementally. These skills are tracing, writing syntax, comprehending templates (reusable abstractions of programming knowledge), and writing code with templates. We theorized that explicit instruction of these skills decreases cognitive demand.

Method: We conducted an exploratory mixed-methods study and compared students’ exercise completion rates, error rates, ability to explain code, and engagement when learning to program. We compared material that reflects this theory to more traditional material that does not distinguish between skills.

Findings: Teaching skills incrementally resulted in improved completion rate on practice exercises, and decreased error rate and improved understanding of the post-test.

Implications: By structuring programming skills such that they can be taught explicitly and incrementally, we can inform instructional design and improve future research on understanding how novice programmers develop understanding.  相似文献   
42.
To explore the university experiences of students with learning disabilities (LD), 63,802 responses to the 2014 Student Experience in the Research University Survey were analyzed. Compared to other students, those with self‐reported LD (5.96 percent) had difficulty with assignments and had more obstacles caused by nonacademic responsibilities and imposed by their skill levels. Students with self‐reported LD sensed more bias toward people with disabilities on campus, and they were less satisfied with their overall experience. Interactions between disability status and age suggested even more challenges for older students who self‐reported LD. Approximately one‐third of students who self‐reported LD received accommodations. The rate of accommodations was higher among individuals who were wealthy, who lived alone, and who were out‐of‐state students. Compared to students who self‐reported LD but reported no accommodations, those with accommodations had more contact with faculty and less difficulty with assignments.  相似文献   
43.
Since outbreaks in 2003, avian influenza has received a considerable amount of funding and become a controversial science policy issue in various respects. Like in many other global and multidisciplinary societal problems fraught with high levels of uncertainty, a variety of perspectives have emerged over how to “tackle” avian influenza and public voices have expressed concern over how research funds are being allocated. In this article, we document if and how research agendas are being informed by public policy debates. We use qualitative and quantitative approaches to examine the relations between expectations of outcomes of public science and the existing research landscape. Interviews with a cross-section of stakeholders reveal a wide range of perspectives and values associated with the nature and objectives of existing research avenues. We find that the landscape of public avian influenza research is not directly driven by expectations of societal outcomes. Instead, it is shaped by three institutional drivers: pharmaceutical industry priorities, publishing and public research funding pressures, and the mandates of science-based policy or public health organizations. These insights suggest that, in research prioritization, funding agencies should embrace a broad perspective of research governance that explicitly considers underlying institutional drivers. Deliberative approaches in public priority setting might help to make agendas more plural and diverse and thus more responsive to the contested and uncertain nature of avian influenza research.  相似文献   
44.
45.
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   
46.
This paper overviews the importance for sports biomechanics of movement variability, which has been studied for some time by cognitive and ecological motor skills specialists but, until quite recently, had somewhat been overlooked by sports biomechanists. The paper considers biomechanics research reporting inter- and intra-individual movement variability in javelin and discus throwing, basketball shooting, and locomotion. The overview does not claim to be comprehensive and we exclude such issues as the theoretical background to movement and coordination variability and their measurement. We overview evidence, both theoretical and empirical, of inter-individual movement variability in seeking to achieve the same task goal, in contrast to the concept of “optimal” movement patterns. Furthermore, even elite athletes cannot reproduce identical movement patterns after many years of training, contradicting the ideas of motor invariance and “representative” trials. We contend that movement variability, far from being solely due to neuromuscular system or measurement “noise” – as sports biomechanists may have previously supposed – is, or could be, functional. Such functionality could allow environmental adaptations, reduce injury risk, and facilitate changes in coordination patterns. We conclude by recommending that sports biomechanists should focus more of their research on movement variability and on important related topics, such as control and coordination of movement, and implications for practice and skill learning.  相似文献   
47.
ABSTRACT

Accelerometer cut points are an important consideration for distinguishing the intensity of activity into categories such as moderate and vigorous. It is well-established in the literature that these cut points depend on a variety of factors, including age group, device, and wear location. The Actigraph GT9X is a newer model accelerometer that is used for physical activity research, but existing cut points for this device are limited since it is a newer device. Furthermore, there is not existing data on cut points for the GT9X at the ankle or foot locations, which offers some potential benefit for activities that do not involve arm and/or core motion. A total of N = 44 adults completed a four-stage treadmill protocol while wearing Actigraph GT9X sensors at four different locations: foot, ankle, wrist, and hip. Metabolic Equivalent of Task (MET) levels assessed by indirect calorimetry along with Receiver Operating Characteristic (ROC) curves were used to establish cut points for moderate and vigorous intensity for each wear location of the GT9X. Area under the ROC curves indicated high discrimination accuracy for each case.  相似文献   
48.
The purpose of this study was to determine the effects of short-term normoxic and hypoxic exercise on plasma endothelin-1 and nitric oxide levels, and the relationship of arterial compliance and pulmonary artery pressure to endothelin-1. Seven endurance-trained males completed two incremental and two steady-state exercise tests performed at ventilatory threshold in normoxia and hypoxia (fraction of inspired oxygen = 0.14). Plasma endothelin-1was measured throughout steady-state tests. Arterial compliance using applanation tonometry, plasma nitric oxide and pulmonary artery pressure using Doppler echocardiography were measured before and after exercise. Small arterial compliance and pulmonary artery pressure significantly increased following exercise. There were no main effects of condition or time for plasma endothelin-1and nitric oxide levels. There were no significant relationships between plasma endothelin-1 and arterial compliance or pulmonary artery pressure. In conclusion, mechanisms other than the endothelial system may play a role in the exercise-induced changes in small artery compliance in this study population. Moderate hypoxia and a 30-minute steady-state exercise have limited effects on plasma endothelin-1 in endurance-trained males.  相似文献   
49.
This article aims to provide a historical and contemporary perspective on how public libraries establish indicators for measuring success, using the Free Library of Philadelphia as a focus of analysis. From the 1970s though the late 1980s, libraries focused on measuring internal statistics, such as bibliographic resources, to communicate the strength of their collection. Within the past twenty years, libraries have shifted their measurement structures toward outward performance in the communities they serve. The challenge today for libraries such as the Free Library is to establish structured formats for guiding community plans for their particular library and establishing agreed-on measures. Simultaneously, these structures need to incorporate ongoing evaluation methods.  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