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   4092篇
  免费   46篇
  国内免费   9篇
教育   3009篇
科学研究   295篇
各国文化   71篇
体育   258篇
综合类   3篇
文化理论   25篇
信息传播   486篇
  2023年   12篇
  2022年   40篇
  2021年   65篇
  2020年   133篇
  2019年   181篇
  2018年   220篇
  2017年   216篇
  2016年   193篇
  2015年   125篇
  2014年   191篇
  2013年   979篇
  2012年   139篇
  2011年   137篇
  2010年   132篇
  2009年   131篇
  2008年   126篇
  2007年   115篇
  2006年   101篇
  2005年   69篇
  2004年   56篇
  2003年   75篇
  2002年   56篇
  2001年   50篇
  2000年   48篇
  1999年   37篇
  1998年   29篇
  1997年   34篇
  1996年   22篇
  1995年   26篇
  1994年   29篇
  1993年   25篇
  1992年   20篇
  1991年   30篇
  1990年   24篇
  1989年   22篇
  1988年   17篇
  1987年   24篇
  1986年   15篇
  1985年   25篇
  1984年   13篇
  1983年   14篇
  1982年   20篇
  1981年   15篇
  1980年   14篇
  1979年   15篇
  1978年   15篇
  1976年   7篇
  1975年   7篇
  1973年   8篇
  1971年   8篇
排序方式: 共有4147条查询结果,搜索用时 15 毫秒
51.
Blood viscosity has been considered as one of important biophysical parameters for effectively monitoring variations in physiological and pathological conditions of circulatory disorders. Standard previous methods make it difficult to evaluate variations of blood viscosity under cardiopulmonary bypass procedures or hemodialysis. In this study, we proposed a unique microfluidic device for simultaneously measuring viscosity and flow rate of whole blood circulating in a complex fluidic network including a rat, a reservoir, a pinch valve, and a peristaltic pump. To demonstrate the proposed method, a twin-shaped microfluidic device, which is composed of two half-circular chambers, two side channels with multiple indicating channels, and one bridge channel, was carefully designed. Based on the microfluidic device, three sequential flow controls were applied to identify viscosity and flow rate of blood, with label-free and sensorless detection. The half-circular chamber was employed to achieve mechanical membrane compliance for flow stabilization in the microfluidic device. To quantify the effect of flow stabilization on flow fluctuations, a formula of pulsation index (PI) was analytically derived using a discrete fluidic circuit model. Using the PI formula, the time constant contributed by the half-circular chamber is estimated to be 8 s. Furthermore, flow fluctuations resulting from the peristaltic pumps are completely removed, especially under periodic flow conditions within short periods (T < 10 s). For performance demonstrations, the proposed method was applied to evaluate blood viscosity with respect to varying flow rate conditions [(a) known blood flow rate via a syringe pump, (b) unknown blood flow rate via a peristaltic pump]. As a result, the flow rate and viscosity of blood can be simultaneously measured with satisfactory accuracy. In addition, the proposed method was successfully applied to identify the viscosity of rat blood, which circulates in a complex fluidic network. These observations confirm that the proposed method can be used for simultaneous measurement of viscosity and flow rate of whole blood circulating in the complex fluid network, with sensorless and label-free detection. Furthermore, the proposed method will be used in evaluating variations in the viscosity of human blood during cardiopulmonary bypass procedures or hemodialysis.  相似文献   
52.
53.
This paper describes an assessment of a web‐based interview simulation designed to teach empathetic helping skills. The system includes an animated character acting as a client and responses designed to recreate a simulated role‐play, a common assessment method used for teaching these skills. The purpose of this study was to determine whether learning gains found in previous evaluations would transfer to students needing similar skill sets but in different areas of study. Findings indicate a positive trend in learning gains across both areas of study (human services and counselling) with no significant differences in skill acquisition. Developers of the system conclude that the system is effective in the general training of empathetic helping skills regardless of the students' area of study.  相似文献   
54.
The direction that secondary school reform should take has become a contested question in the province of Ontario, Canada, during the 1990s. This case study of one secondary school examines some of the issues surrounding the transition years. Two policies, destreaming and integration, mandatedbythe OntarioMinistryof Education in 1993, and fully implemented by 1995, are examined by means of interview and survey. Administrators, teachers and students commented on the transition from elementary to secondary school. We discuss questions related to destreaming (especially how teachers contend with mixed-ability classes) and integration (with a particular focus on mathematics, science and technology).  相似文献   
55.
Attention-deficit/hyperactivity disorder (ADHD) and learning disabilities (LD) are the most commonly diagnosed childhood disorders, and they frequently co-occur with each other. It has been found that students with comorbidity of ADHD and LD experience more difficulties in school. Even though the research interests in the comorbidity of ADHD and LD are increasing, there are inconsistent results in research studies and insufficient understanding of the comorbidity of ADHD and LD. This study attempts to grasp the progress of the studies in the comorbidity of ADHD and LD in Korea and to suggest the future directions for following research. A total of 90 studies published between 1987 and 2009 are examined. First, we analyze the studies that examined the learning problems of ADHD and then identify the characteristics of the learning problems in ADHD group. Afterwards, we investigate the studies that dealt with the attention problems of LD and then discuss the characteristics of the attention problems in LD group. Third, we identify the differences between ADHD and LD and synthesize the research findings. Finally, we analyze the studies conducted in conjunction with the comorbidity of ADHD and LD. On lightening the research of the comorbidity on three aspects, we find the research trend in Korea and provide the implications for future studies on the comorbidity of ADHD and LD. Furthermore, we suggest that it is important to identify comorbid conditions at the early stage, and it is necessary to conduct multidisciplinary research and international comparison research.  相似文献   
56.
57.
ABSTRACT

Online learning has become a ubiquitous part of the educational landscape and how teachers are supported in developing approaches to teaching online is a fundamental aspect of the students’ learning experience. Based on the implementation of a professional development course on becoming an online teacher offered in a blended learning mode at one university in Hong Kong, this article proposes that offering this type of professional development in a blended mode is very effective in facilitating enhanced usage of the university’s learning management system. In a blended mode, teachers are actively engaged with blended learning and were found to make more extensive use of features/tools in Blackboard after they attended the professional development course. Results support that offering professional development in a blended mode provides teachers with an authentic student perspective, at the same time as they take guided steps in the teacher’s role in blended learning.  相似文献   
58.
This study employed the uses and gratification approach to investigate how journalists perceive relational satisfaction with the public on Twitter, specifically the associations between journalists’ motivations to use Twitter, their Twitter use, and their relational satisfaction with the public. Through a survey of South Korean journalists, this study revealed that journalists’ motivations for Twitter use are positively related to their job-related activities on Twitter (e.g., posting/sharing their news and interacting with audience), which consequently influences perceived relational satisfaction with the public. The findings provide new insight into an increasingly important part of the public’s engagement and news/information flows in the digital media environment. This study expands upon the literature by analyzing how journalists’ motivations for using Twitter and their job-related activities on Twitter are associated with relational satisfaction with the public.  相似文献   
59.
This paper examines the video-based pedagogical practices of Terry (pseudonym), a head coach of a professional junior academy squad. Data were collected through 6 in-depth, semi-structured interviews and 10 field observations of Terry’s video-based coaching in situ. Three embracing categories were generated from the data. These demonstrated that Terry’s video-based coaching was far from apolitical. Rather, Terry strategically used performance analysis technologies to help fulfil various objectives and outcomes that he understood to be expected of him within the club environment. Kelchtermans’ micropolitical perspective, Callero’s work addressing role and Groom et al.’s grounded theory were primarily utilised to make sense of Terry’s perceptions and actions. The findings point to the value of developing contextually grounded understandings of coaches’ uses of video-based performance analysis technology. Doing so could better prepare coaches for this aspect of their coaching practice.  相似文献   
60.
Abstract

This paper explores the migration of female basketball players from Taiwan to China. Governance theory is adopted as the framework in this study to analyze the phenomenon of players’ migration and to understand how it was shaped over the years. The empirical work draws on a qualitative approach, which is based on a review of documentary materials and semi-structured interviews; coding and analysis were undertaken with a content analysis approach in order to investigate the decision-making processes and their consequences for the players’ migration. The feature of systematic governance for the development of women’s basketball has been revealed in this study. Stakeholders with personal interests caused the downturn of women’s basketball development in Taiwan, and it eventually led to the players’ migration abroad. Through the lens of governance theory, it has been revealed that a number of factors – namely, political, financial, personal, socio-economic, and cultural – all intertwine with one another dynamically to influence the female players’ decision to move abroad. This finding broadens the scope for the research of Taiwanese athletes’ migration to China, extending the focus from only business or industry to other aspects, thereby highlighting the fact that the subject is more complex than previously understood.  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