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   3020篇
  免费   32篇
  国内免费   9篇
教育   2103篇
科学研究   279篇
各国文化   53篇
体育   232篇
综合类   2篇
文化理论   22篇
信息传播   370篇
  2023年   12篇
  2022年   31篇
  2021年   54篇
  2020年   106篇
  2019年   127篇
  2018年   153篇
  2017年   155篇
  2016年   143篇
  2015年   99篇
  2014年   140篇
  2013年   743篇
  2012年   104篇
  2011年   93篇
  2010年   99篇
  2009年   92篇
  2008年   88篇
  2007年   75篇
  2006年   68篇
  2005年   36篇
  2004年   33篇
  2003年   50篇
  2002年   35篇
  2001年   38篇
  2000年   33篇
  1999年   27篇
  1998年   17篇
  1997年   22篇
  1996年   23篇
  1995年   19篇
  1994年   14篇
  1993年   21篇
  1992年   16篇
  1991年   23篇
  1990年   10篇
  1989年   17篇
  1988年   11篇
  1987年   22篇
  1986年   13篇
  1985年   24篇
  1984年   13篇
  1983年   14篇
  1982年   19篇
  1981年   14篇
  1980年   12篇
  1979年   15篇
  1978年   13篇
  1977年   7篇
  1975年   9篇
  1973年   6篇
  1971年   7篇
排序方式: 共有3061条查询结果,搜索用时 15 毫秒
71.
72.
Experiences of violence and behaviors that increase the risk of acquiring a sexually transmitted infection are high among women in the United States, and they often intersect (Meyer, Springer, &; Altice, 2011 Meyer, J. P., Springer, S. A., &; Altice, F. L. (2011). Substance abuse, violence, and HIV in women: A literature review of the syndemic. Journal of Women's Health (2002), 20(7), 9911006. doi:10.1089/jwh.2010.2328[Crossref] [Google Scholar]; Montgomery et al., 2015 Montgomery, B., Rompalo, A., Hughes, J., Wang, J., Haley, D., Soto-Torres, L., &; Hodder, S. (2015). Violence against women in selected areas of the united states.e1-e11. Am J Public Health, 105(10), 21562166 [Google Scholar]; World Health Organization (WHO), 2010 World Health Organization (WHO). (2010). Addressing violence against women and HIV/AIDS: What works?. Geneva, Switzerland: World Health Organization. [Google Scholar]). However, there are few evidence-based HIV-prevention interventions that address the special needs and challenges faced by female survivors of violence (Centers for Disease Control and Prevention, (CDC), 2017a Centers for Disease Control and Prevention. (2017a). Compendium of evidence-based interventions and best practices for HIV prevention. Atlanta, GA: Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, Sexual Transmitted Diseases and Tuberculosis Prevention. Retrieved from https://www.cdc.gov/hiv/research/interventionresearch/compendium/rr/index.html [Google Scholar]). To address this gap, we adapted and pilot-tested an existing evidence-based women-focused sexual risk-reduction intervention (The Future Is Ours) with 23 self-identified female survivors of violence. The intervention comprised eight-weekly, two-hour cognitive behavioral group sessions focusing on reducing sexual-risk and improving trauma-based coping skills. Using mixed-methods analyses, the adapted intervention was determined feasible and acceptable to participants, and preliminary results suggest that participation could reduce risk factors for sexually transmitted infections. Therefore, testing on a larger scale is warranted.  相似文献   
73.
It is difficult to motivate learners to seek out and persist at challenging learning tasks where failure is likely. However, in game environments, people seem highly motivated to engage with challenges and respond productively to failure. Many typical game features purportedly enhance intrinsic motivation and self-efficacy, which should improve students’ reactions to challenge and failure, which should in turn enhance learning. An experimental study with early middle school students tested these assumptions by comparing a “Full” version of a typical, commercial programming game to a “Minimal” version of the same game where common game features such as narrative, performance metrics, high-quality graphics, and sound were removed. In contrast to our hypotheses, players of the Full Game were less likely to choose coding challenges, were less tolerant of coding failures and gained less coding knowledge. Intrinsic motivation and self-efficacy did not differ between conditions. Correlational analyses showed that failure tolerance and challenge seeking may critically affect learning from educational games. The current study offers an existence proof that some common game features can hinder players' failure tolerance, challenge-seeking and learning, in certain game contexts. Future research should isolate the effects of individual game features, test generalizability and explore which contextual variables influence the findings.  相似文献   
74.
International Journal for Educational and Vocational Guidance - This study provides insights into how Chinese adolescents in Hong Kong interpret the concept of “meaning in life.” Data...  相似文献   
75.
Willmott GR  Platt M  Lee GU 《Biomicrofluidics》2012,6(1):14103-1410315
Tunable pores (TPs) have been used for resistive pulse sensing of 1 μm superparamagnetic beads, both dispersed and within a magnetic field. Upon application of this field, magnetic supraparticle structures (SPSs) were observed. Onset of aggregation was most effectively indicated by an increase in the mean event magnitude, with data collected using an automated thresholding method. Simulations enabled discrimination between resistive pulses caused by dimers and individual particles. Distinct but time-correlated peaks were often observed, suggesting that SPSs became separated in pressure-driven flow focused at the pore constriction. The distinct properties of magnetophoretic and pressure-driven transport mechanisms can explain variations in the event rate when particles move through an asymmetric pore in either direction, with or without a magnetic field applied. Use of TPs for resistive pulse sensing holds potential for efficient, versatile analysis and measurement of nano- and microparticles, while magnetic beads and particle aggregation play important roles in many prospective biosensing applications.  相似文献   
76.
Lee K  Kim C  Young Yang J  Lee H  Ahn B  Xu L  Yoon Kang J  Oh KW 《Biomicrofluidics》2012,6(1):14114-141147
We propose a simple method for forming massive and uniform three-dimensional (3-D) cell spheroids in a multi-level structured microfluidic device by gravitational force. The concept of orienting the device vertically has allowed spheroid formation, long-term perfusion, and retrieval of the cultured spheroids by user-friendly standard pipetting. We have successfully formed, perfused, and retrieved uniform, size-controllable, well-conditioned spheroids of human embryonic kidney 293 cells (HEK 293) in the gravity-oriented microfluidic device. We expect the proposed method will be a useful tool to study in-vitro 3-D cell models for the proliferation, differentiation, and metabolism of embryoid bodies or tumours.  相似文献   
77.
国产十种乌头的染色体研究   总被引:1,自引:0,他引:1  
本文描述了我国产毛茛科乌头属的10个种的染色体数目和形态。  根据该属染色体基 数为8(x=8),可将这些种归为二倍体、四倍体、六倍体和八倍体种。  10种乌头的染色体在数目、大小、结构上表现出相关性。其中具根状茎而多年生的种多为二倍体,染色体形态较大,第3-7号多为近端着丝点(st)染色体, 具块茎而二年生的种多为多倍体,染色体形态较小,第3-7号多为近中着丝点(sm)染色体。染色体演化方向可能是二倍体→多倍体、大→ 小、st→sm。这进一步证明根状茎种较块茎种原始。根据染色体数目和形态,又可将这些种的染色体分为两类。这进一步支持了目前分类学上的牛扁亚属和乌头亚属的划分。本文还讨论了这些种的有关分类问题。  相似文献   
78.
Concurrent droplet charging and sorting by electrostatic actuation   总被引:1,自引:0,他引:1  
This paper presents a droplet-based microfluidic device for concurrent droplet charging and sorting by electrostatic actuation. Water-in-oil droplets can be charged on generation by synchronized electrostatic actuation. Then, simultaneously, the precharged droplets can be electrostatically steered into any designated laminar streamline, thus they can be sorted into one of multiple sorting channels one by one in a controlled fashion. In this paper, we studied the size dependence of the water droplets under various relative flow rates of water and oil. We demonstrated the concurrent charging and sorting of up to 600 droplets∕s by synchronized electrostatic actuation. Finally, we investigated optimized voltages for stable droplet charging and sorting. This is an essential enabling technology for fast, robust, and multiplexed sorting of microdroplets, and for the droplet-based microfluidic systems.  相似文献   
79.
For the last 70 years, since the establishment of the Republic of Korea, Korean education has achieved universal expansion of educational opportunity from elementary to secondary to higher education. Planning, centralized policy making, top-down implementation, and administrative control had been the standards of the first few decades of Korean education. The so-called May 31 education reform implemented in 1995 made a turning point for these approaches to education policy and administration by highlighting autonomy, openness, diversity, accountability, consumer centeredness, market control, and governance for quality education. However, these government-driven education reform initiatives have resulted in limiting the expected outcomes. In this paper, the authors call for a new approach to education policy and administration and propose supporting school innovation, empowering an internal accountability system in governance. The authors also suggest a search for normative values for democratic communitarianism as a new philosophical foundation of education policy framework, beyond instrumental values of education.  相似文献   
80.
Abstract

Over the last decade, school-based professional learning communities (PLCs) have emerged as a key feature of the education system in South Korea. To understand this relatively new phenomenon in the context of South Korea, we provide a review of research on school-based PLCs in South Korea and an empirical analysis of the Teaching and Learning International Survey (TALIS) 2008 with a focus on school-based PLCs. Based on our findings from the literature review and analysis of the TALIS, we aim to provide a fuller picture of the emerging landscape of school-based PLCs in South Korean schools. In so doing, we focus on what constitutes school-based PLCs in South Korean schools and how they are similar to and/or different from their counterparts in other countries. Implications for policy, practice, and research are discussed.  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