全文获取类型
收费全文 | 331篇 |
免费 | 1篇 |
国内免费 | 75篇 |
专业分类
教育 | 137篇 |
科学研究 | 133篇 |
各国文化 | 3篇 |
体育 | 32篇 |
综合类 | 8篇 |
信息传播 | 94篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 14篇 |
2019年 | 15篇 |
2018年 | 17篇 |
2017年 | 17篇 |
2016年 | 22篇 |
2015年 | 24篇 |
2014年 | 24篇 |
2013年 | 34篇 |
2012年 | 36篇 |
2011年 | 25篇 |
2010年 | 20篇 |
2009年 | 21篇 |
2008年 | 24篇 |
2007年 | 23篇 |
2006年 | 20篇 |
2005年 | 9篇 |
2004年 | 16篇 |
2003年 | 9篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有407条查询结果,搜索用时 328 毫秒
31.
《普罗米修斯》2012,30(3):237-245
This article describes the use of wireless telecommunication media within the different locations directly affected by the hijackings on September 11. Comparisons across these different contexts provides an empirical anchor to more general themes concerning the social dynamics of wireless in the unfolding events of this day. An indication is given of how the important social role of wireless phones in this crisis could redefine public views on wireless media and thereby shape policy and regulation in the years ahead. 相似文献
32.
生态系统服务消耗及其影响 总被引:2,自引:0,他引:2
对生态系统服务直接与间接消耗的模式、机制与影响研究,以及如何把人类对生态系统服务消耗与自然生态系统本身结合起来,是富有挑战性和前瞻性的研究工作。但是,生态系统服务消耗仍然是一个及其需要强化的研究领域。本文结合村落及区域尺度研究进展,分析了生态系统服务直接与间接消耗的特点,阐述了消耗及其格局变化对生态系统本身的影响,以及对土地资源质量和数量、对水资源数量和产能影响的特点。同时,论述了实现从农户到区域尺度个体生态服务消耗模式变化及区域演变规律的跨尺度定量模拟与表达,为实现可持续消耗模式及生态系统适应性管理提供参考。 相似文献
33.
The geometric shapes of specimens are important in impact tensile tests because geometric shapes determine the stress states of the specimens, and precise geometric shapes can obtain proper material properties without non-material factors. The aim of this study was to investigate the 1D form of the stress by changing the length-to-diameter (L/D) ratios of specimens. The experiments were carried out on a split Hopkinson tensile bar (SHTB)-rotating disk indirect bar-bar tensile impact apparatus. The L/D ratios of the LY12CZ specimens used in the test ranged from 1 to 5. Results show that the specimens can be used to obtain exact parameters of materials under the proposed conditions when the L/D ratio is greater than 2. This is because the longer length will reduce or eliminate the effects of the interfaces. 相似文献
34.
35.
技术选择对技术生态环境有着重要的影响作用。本文从介绍技术生态环境概念入手,在分析了信息与通信产业技术相关特征的基础上,剖析了信息与通信技术对产业技术生态系统的影响作用,最后,提出了信息与通信产业技术选择与其技术生态环境协同发展的策略。 相似文献
36.
Nancy B. Kurland 《The Information Society》1996,12(4):387-406
Information technology in the form of the Internet and its commercial offspring (referred to in this article collectively as the Net) has received much attention as a vehicle to increase political participation. In this article, we explore the potential of the Net, a vast, loosely coupled system of electronic forums, for facilitating and hindering democratic participation. In so doing, we identify five assumptions that undergird the claim that the Net will enhance democratic participation and suggest that increased democratic participation rests on three fundamental characteristics: access, voice, and dialogue. In order for this network of electronic forums to facilitate democratic participation, educational, economic, and cultural barriers to access, voice, and dialogue must be overcome. The final part of this article raises additional challenges to realizing democracy via the Net. 相似文献
38.
欧盟的东扩给欧洲所力主推行的防务一体化带来了一系列负面影响,新成员的加入带来了新的问题,同时加剧了欧盟内部在防务一体化上原本存在的问题如防务目标相异、实力与目标不相称、防务能力的结构性缺陷、受美国影响加深,这些问题是欧洲防务一体化所无法回避的,它们的解决有赖于扩大后的欧盟的整合。 相似文献
39.
Vincent Mitchell 《高等教育研究与发展》2019,38(4):819-832
ABSTRACTResearch impact features heavily in debates about ‘the measured university’ and is now formally assessed by governments in the UK and Australia. Yet clear guidance on how impact can be measured in non-monetary ways is often lacking because of confused thinking and the context-specific nature of outcomes. To help resolve this, we first propose a general impact model of inputs, processes, outputs and outcomes framework. Then, using a survey approach of research users, we measure outcomes at different levels of abstraction using usefulness as the central construct and impact categories from the European (EU) and Association to Advance Collegiate Schools of Business (AACSB). The survey measures are simple, comparable between different impact cases, cost-effective, externally verifiable, and easily administered by those for whom impact measurement is new and puzzling. They can also be combined to form an impact index to address criticism that there is little standardisation in impact measurement. To improve the standardisation of context-specific measures, we suggest a common methodology for deriving these (SROI). The article discusses limitations of using surveys including administration, self-report data, and impact timescale problems, and suggests ways to reduce these. Implications for researchers, research managers, and assessors interested in measuring impact, such as who should do it and pay for it, are discussed. 相似文献
40.
时间在新闻叙事中是个重要问题,而东西方对时间的认识和使用体现出各种差异,例如,时间循环性和时间线行性差异,多向时间思维和单向时间思维差异,以及事间的整体性和时间的可分割性等诸多差异。这些思维差异也反映在新闻叙事中,微妙地影响着新闻叙事的思路和结构。 相似文献