全文获取类型
收费全文 | 3420篇 |
免费 | 55篇 |
国内免费 | 123篇 |
专业分类
教育 | 1689篇 |
科学研究 | 683篇 |
各国文化 | 15篇 |
体育 | 255篇 |
综合类 | 144篇 |
文化理论 | 4篇 |
信息传播 | 808篇 |
出版年
2024年 | 5篇 |
2023年 | 25篇 |
2022年 | 54篇 |
2021年 | 94篇 |
2020年 | 147篇 |
2019年 | 102篇 |
2018年 | 127篇 |
2017年 | 61篇 |
2016年 | 59篇 |
2015年 | 96篇 |
2014年 | 219篇 |
2013年 | 337篇 |
2012年 | 292篇 |
2011年 | 265篇 |
2010年 | 230篇 |
2009年 | 223篇 |
2008年 | 243篇 |
2007年 | 231篇 |
2006年 | 182篇 |
2005年 | 138篇 |
2004年 | 112篇 |
2003年 | 107篇 |
2002年 | 80篇 |
2001年 | 46篇 |
2000年 | 34篇 |
1999年 | 14篇 |
1998年 | 18篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 1篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1989年 | 2篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1978年 | 5篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1957年 | 1篇 |
排序方式: 共有3598条查询结果,搜索用时 15 毫秒
91.
Endogenous technical advance and the stochastic trend in output: A neoclassical approach 总被引:2,自引:0,他引:2
In the recent endogenous growth literature, the trend in output is stochastic, while investment in scientific knowledge is treated as analogous to a capital stock. This paper models both research and development (R&D) and disembodied technical advance using neo-classical equations, which specify the equilibrium stocks as a function of prices and output. The elasticity of R&D in the production function, estimated using factor shares, is time-varying and increasing. Returns to scale are increasing in all factors. The most important aspect of the model is that the equilibrium rate of technical advance is not cyclically invariant, but co-moves with output at business cycle frequencies. This allows the production function to behave as a stochastic trend. Growth accounting demonstrates that long-term variations in the rate of productivity growth have been associated mainly with low-frequency fluctuations in the rate of disembodied technical advance, with secondary effects from the stocks of R&D and physical capital. During the high productivity period 1948–1972, technical advance contributed 1.48 percentage points per year to output, with 0.98 accounted for by R&D. The productivity slowdown of the mid-1970s was accounted by a gradual decline in the effect of R&D, and a more abrupt collapse in disembodied technology. The subsequent productivity revival was associated with two accelerations in disembodied technical advance, the first beginning in the early 1980s, and the second in the mid-1990s. The production function is simulated in a small econometric model. Model simulations find that exogenous shocks to the inflation rate generate significant variations in growth by inducing fluctuations in disembodied technology. 相似文献
92.
Motivated by recent statistics that show significant growth in labor productivity, this paper seeks to analyze the long-term relationship between domestic R&D, knowledge stock and productivity dynamics. Time series data of the German manufacturing industry is used to estimate a variable cost function with the stock of knowledge being dependent upon current and past R&D spending. The estimates indicate that 50% of the effects of R&D on the knowledge stock appear within 4 years. However, the rate of return on R&D are shown to be drastically declining; recent rates of return on R&D are estimated to have reached an all-time low spanning the last 45 years. Current yields of R&D are only one third compared to the sixties. In conclusion, though the productivity slowdown of the seventies seems to have been overcome, this is not attributed to R&D investments. 相似文献
93.
94.
构建高效规范的科技评价体系是我国科技治理体系和治理能力现代化的重要标志.以中国知网数据库2017-2019年科技评价领域的期刊论文为对象,分析近年来的研究热点分布及演化特征、主要研究机构及合作关系.研究发现:我国科技评价领域的研究热点包括高质量科技成果评价、学科评估、绩效评价、多元化评价方法等,符合国家科技评价改革方向;领域宽泛但缺少统一的学术语言和共同的认知理念,给学术研究和评价实践带来挑战;对评价方法的探索已成为主要研究方向,定量分析、大数据分析以及针对"分类评价""破四唯"等改革导向的分析已成趋势;研究机构以高校为主,学术研究与实践工作存在一定脱节.对未来我国科技评价体系的改革提出四点建议,包括坚持政策引导、建立行业共识、加强方法探索、促进研用结合等. 相似文献
95.
96.
Fred Chou Janelle Kwee Robert Lees Kara Firth Jordan Florence Jake Harms 《Educational Action Research》2013,21(3):436-459
This Youth Participatory Action Research (YPAR) study represents a collaboration with six students from alternative education to inquire about the experiences of vulnerable youth – students in alternative education and youth who have dropped out of school. Utilizing the Enhanced Critical Incident Technique, youth researchers asked their peers what helped and hindered their retention and success in mainstream and alternative education. Youth researchers engaged in authentic participation and took part in the iterative phases of YPAR – critical reflection and social action. Their involvement empowered them to advocate for their peers by disseminating the results and recommendations to key stakeholders within the community. Youth researchers conducted semi-structured interviews with 18 participants. Overall, the findings show that relationships with staff and peers, flexibility, psychosocial and academic supports, and personal circumstances are vital in helping vulnerable students succeed in school. Engagement in YPAR provided insight into working with vulnerable youth in a manner that promotes agency and social change within educational institutions. 相似文献
97.
文学研究会和创造社作为20世纪20年代最有影响的文学社团,以客居的身份初登文坛,但是他们并不甘心如此边缘化的处境,寻求自身生存发展的谋略,笔者探究文学研究会和创造社共同显露出的以名人效应、依附报刊取得阵地和策略化文学论争的手段由边缘向中心动态移动的形态,阐释了"子辈"社团对"父辈"社团的超越以取得文坛话语权。 相似文献
98.
情感能力是人类智能的重要标志,情感的缺失会影响网络远程教育的教学质量和学习者的学习效果。情感计算是和谐人机交互与人工智能领域中新的研究方向。在网络远程教育系统中应用情感计算理论与技术,可以进一步优化网络远程教育的功能,帮助教师监测远程学习者的情感变化,调整教学策略和方法,实时给予学习者情感反馈,使教学质量达到最佳。目前国内外情感计算在远程教育方面的应用研究还处于起步与探索阶段,所构建的远程教学系统对远程教学中师生情感生理特征与心理特征、多模情感信息融合机制及网络虚拟人机情感交互特性等考虑不足,系统原型在情感合成与表达、智能人机情感交互实现上存在着很大的难度。因此,构建与人类情感系统相吻合的、自然和谐的、人性化和智能化的网络远程教育系统,需要有效解决师生面部表情、语音情感特征信号的准确识别与提取,师生多模情感信息融合机制与和谐人机情感交互技术等关键问题。 相似文献
99.
Important innovations are increasingly produced based on research engagement and fertilization across industries. However, we know little about the challenges associated with managing innovation networks in specific contexts that involves researchers in cross-industry collaboration. Against this backdrop, we draw on theory on design and orchestration of innovation networks to analyze a large-scale government sponsored program, “ProcessIT Innovations” that was designed to increase competitiveness and accelerate economic growth in Northern Sweden. The program was initiated and led by firms from the traditionally strong local process industry and engaged local researchers and firms from the emerging IT industry. Based on our analyses, we offer two contributions. First, we provide a detailed analysis of the challenges related to configuration of the network, orchestration of partnerships between participants, and facilitation of innovation in dedicated development projects. Second, we propose a model of managing research and innovation networks through fertilization across industries and between firms and research institutions. 相似文献
100.
我国的一些优秀图书情报学专家的学术成就证明,有中国特色的高水平的研究,必须广泛借鉴东西方的学术思想,否则将导致学术研究中的片面性和片断性,难以形成完整的学术体系和科学思想,要批判地借鉴国外图书情报学流派,还必须克服固守传统和追随新潮这两种倾向。恰当地对待国外近代图书情报学的传统及其成果。 相似文献