全文获取类型
收费全文 | 17404篇 |
免费 | 357篇 |
国内免费 | 288篇 |
专业分类
教育 | 11712篇 |
科学研究 | 2524篇 |
各国文化 | 28篇 |
体育 | 1611篇 |
综合类 | 1391篇 |
文化理论 | 28篇 |
信息传播 | 755篇 |
出版年
2024年 | 11篇 |
2023年 | 56篇 |
2022年 | 193篇 |
2021年 | 317篇 |
2020年 | 341篇 |
2019年 | 258篇 |
2018年 | 182篇 |
2017年 | 186篇 |
2016年 | 246篇 |
2015年 | 469篇 |
2014年 | 1044篇 |
2013年 | 977篇 |
2012年 | 1428篇 |
2011年 | 1578篇 |
2010年 | 1112篇 |
2009年 | 1097篇 |
2008年 | 1256篇 |
2007年 | 1457篇 |
2006年 | 1248篇 |
2005年 | 1061篇 |
2004年 | 931篇 |
2003年 | 818篇 |
2002年 | 630篇 |
2001年 | 502篇 |
2000年 | 257篇 |
1999年 | 114篇 |
1998年 | 58篇 |
1997年 | 55篇 |
1996年 | 57篇 |
1995年 | 19篇 |
1994年 | 21篇 |
1993年 | 22篇 |
1992年 | 19篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1985年 | 1篇 |
1977年 | 1篇 |
1957年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
991.
政府直接补贴风投机构政策的合理性取决于其有效性。本文首次将三方演化博弈方法引入相关研究,构建包含政府、创业企业和风投机构的非合作演化博弈模型,并求解演化稳定均衡及其条件。两个基本结论为:政府直接补贴政策在长期中无效;演化稳定均衡点的形成主要基于“金融市场的平均利率”与“风投机构的资源整合能力”的协同影响。本文认为缺乏政策粘性是导致结论1“政府直接补贴政策在长期中无效”的内在机理,并采用数值模拟及现实证据进一步夯实了结论1。最后,基于上述结论2,提出促进风投市场发展的政策建议:促进增值服务中介发展,借鉴YOZMA模式提高风投机构的准入门槛,引导资本脱虚向实和完善地区金融市场。 相似文献
992.
Hardware gimmick or cultural innovation? Technological, cultural, and social foundations of the Japanese video game industry 总被引:1,自引:0,他引:1
This paper examines the role of creative resources in the emergence of the Japanese video game industry. We argue that creative resources nurtured by popular cartoons and animation sector, combined with technological knowledge accumulated in the consumer electronics industry, facilitated the emergence of successful video game industry in Japan. First we trace the development of the industry from its origin to the rise of platform developers and software publishers. Then, knowledge and creative foundations that influenced the developmental trajectory of this industry are analyzed, with links to consumer electronics and in regards to cartoons and animation industry. 相似文献
993.
994.
995.
赵景柱 《中国科学院研究生院学报》1996,(1)
用对策论研究生物行为的进化过程,是近年来对策论具有开创性的应用之一,而判断和求解进化对策的进化稳定策略(EvolutionaryStableStrategy,简记为ESS)则是其中的关键[1,2].研究具有两类局中人的进化对策模型,证明这种进化对策的ESS存在的充要条件.根据这个条件可以判定这种进化对策是否具有ESS,且当ESS存在时,可求出ESS. 相似文献
996.
知识产权作为知识经济时代最重要的生产要素,已成为企业核心竞争力的集中体现。现有对专利权经济价值的研究,多以所有权的观念研究专利排他权,热衷于专利量化指标及其计算公式,以致脱离了专利制度和产业事实,与知识经济发展的要求不相协调。专利权经济价值分析应与专利权的创造、运用、保护、管理相呼应,分析过程能够反映专利质量和专利作业要求。 相似文献
997.
Recent advances in wireless technologies have led to the development of intelligent, in-vehicle safety applications designed
to share information about the actions of nearby vehicles, potential road hazards, and ultimately predict dangerous scenarios
or imminent collisions. These vehicle safety communication (VSC) technologies rely on the creation of autonomous, self-organizing,
wireless communication networks connecting vehicles with roadside infrastructure and with each other. As the technical standards
and communication protocols for VSC technologies are still being developed, certain ethical implications of these new information
technologies emerge: Coupled with the predicted safety benefits of VSC applications is a potential rise in the ability to
surveil a driver engaging in her everyday activities on the public roads. This paper will explore how the introduction of
VSC technologies might disrupt the “contextual integrity” of personal information flows in the context of highway travel and
threaten one’s “privacy in public.” Since VSC technologies and their related protocols and standards are still in the developmental
stage, the paper will conclude by revealing how close attention to the ethical implications of the remaining design decisions
can inform and guide designers of VSC technologies to create innovate safety applications that increase public safety, but
without compromising the value of one’s privacy in public.
This work was supported by the National Science Foundation PORTIA Grant No. CNS-0331542, and could not have been completed
without the valuable guidance of Prof. Helen Nissenbaum (New York University) and Prof. Dan Boneh (Stanford University). I
am grateful to many other colleagues who generously contributed to this work with excellent comments and suggestions, including
Emily Clark and Steve Tengler at the VSCC, and Sam Howard-Spink, Joseph Reagle and Tim Weber at New York University. Drafts
were further sharpened through opportunities to present at colloquia and conferences sponsored by New York University’s Department
of Culture & Communication, the American Association for the Advancement of Science, the Society for Philosophy and Technology,
and Computer Ethics: Philosophical Enquiry. 相似文献
998.
By using a sample of 793 inventors drawn from the PatVal-EU dataset, this paper explores three aspects of patent production at the individual inventor level: (1) the number of EPO patents that the inventors produce; (2) the average value of their inventions; (3) the production of the most valuable patents. By jointly estimating the three equations we find that the inventors’ level of education, employment in a large firm, and involvement in large-scale research projects positively correlate with quantity. Yet, apart from the size of the research project, none of these factors directly influence the expected value of the inventions. They do, however, have an indirect influence, as we find that the number of patents explains the probability of producing a technological hit (the maximum value). Also, there is no regression to the mean in the invention process at an individual level, as the number of inventions that an inventor produces is not correlated with the average value. 相似文献
999.
信息增值服务--未来图书馆工作的核心 总被引:7,自引:0,他引:7
随着现代技术的发展、信息资源的丰富和用户需求的不断提高,使得传统图书馆员的工作出现危机。本文从信息增值相关概念分析、图书馆与文献信息增值的关系和信息增值服务模式三方面进行分析论述。得出结论:追求文献信息增值最大化是图书馆不变的主题,提供信息增值服务是未来图书馆工作的核心。 相似文献
1000.