全文获取类型
收费全文 | 1073篇 |
免费 | 42篇 |
国内免费 | 40篇 |
专业分类
教育 | 655篇 |
科学研究 | 241篇 |
各国文化 | 6篇 |
体育 | 70篇 |
综合类 | 162篇 |
文化理论 | 3篇 |
信息传播 | 18篇 |
出版年
2023年 | 4篇 |
2022年 | 21篇 |
2021年 | 34篇 |
2020年 | 50篇 |
2019年 | 24篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 25篇 |
2015年 | 32篇 |
2014年 | 80篇 |
2013年 | 82篇 |
2012年 | 102篇 |
2011年 | 87篇 |
2010年 | 71篇 |
2009年 | 75篇 |
2008年 | 58篇 |
2007年 | 85篇 |
2006年 | 76篇 |
2005年 | 52篇 |
2004年 | 45篇 |
2003年 | 30篇 |
2002年 | 35篇 |
2001年 | 22篇 |
2000年 | 13篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有1155条查询结果,搜索用时 15 毫秒
1.
Smart cities employ information and communication technologies to improve: the quality of life for its citizens, the local economy, transport, traffic management, environment, and interaction with government. Due to the relevance of smart cities (also referred using other related terms such as Digital City, Information City, Intelligent City, Knowledge-based City, Ubiquitous City, Wired City) to various stakeholders and the benefits and challenges associated with its implementation, the concept of smart cities has attracted significant attention from researchers within multiple fields, including information systems. This study provides a valuable synthesis of the relevant literature by analysing and discussing the key findings from existing research on issues related to smart cities from an Information Systems perspective. The research analysed and discussed in this study focuses on number of aspects of smart cities: smart mobility, smart living, smart environment, smart citizens, smart government, and smart architecture as well as related technologies and concepts. The discussion also focusses on the alignment of smart cities with the UN sustainable development goals. This comprehensive review offers critical insight to the key underlying research themes within smart cities, highlighting the limitations of current developments and potential future directions. 相似文献
2.
谢梦 《自然科学博物馆研究》2019,(6):55-59
海洋出水木质文物和陆地考古发掘出土木质文物相比,生物类病害表现得特别明显。借鉴海洋工程学和“南海I号”相关研究成果,我们将导致古代木质沉船腐蚀的生物分为三大类:海洋植物、海洋动物和海洋微生物。船体的腐蚀过程主要分为三个阶段:固相表面形成生物膜阶段;大型污损生物等的幼体附着于前期形成的生物膜之上阶段;群落趋于稳定、船体木质逐步降解阶段。沉船腐蚀过程中不同生物类群之间共生或寄生在一起形成动态平衡,因此,对于出水木质文物的生物修复应该在保证生物群落稳定的状态下进行,避免单一种群剧烈发展对文物造成的二次损害。 相似文献
3.
为促进海洋生物医药产业资源要素的优化配置,从自然资源、人力资源、资本投入、科学技术和政府政策五个方面选取要素指标,进行灰色关联度分析,以此构建海洋生物医药产业资源要素配置效率评价指标体系,并通过构建CCR- BCC交叉评价模型对2006-2015年间中国沿海11省市(不包括港澳台)海洋生物医药产业资源要素配置效率进行定量测算与等级划分。结果显示:政府资金投入、海洋药物研发经费投入、海洋经济生产总值是影响海洋生物医药产业发展的主要因素,此外,中国沿海11省市海洋生物医药产业资源要素配置效率存在显著的差异,可以划分为4个等级,第1等级有浙江、山东和广东,第2等级有江苏、上海和辽宁,第3等级有福建、天津和河北,第4等级有广西、海南。 相似文献
4.
Tyler Denmead 《Educational theory》2019,69(2):225-240
In this article, Tyler Denmead draws upon critical race theory to argue that the creative city discourse reproduces racial injustice for youth. In particular, the creative city invests in the property rights and profitability of whiteness by inscribing creative superiority on the bodies of young people who are more likely to be privileged by virtue of their race and class. Through evidence collected by both autoethnographic and ethnographic methods, Denmead discusses how his history as an arts educator has been entangled in the manifestation of this racist reconfiguration of urban space in one particular American city, Providence, Rhode Island. He discovered that the racial dynamics of the creative city discourse have productive power over how young people construct their identities and make life choices in this city and, further, that those dynamics operate in and through artist partnerships between those positioned as creatives and those positioned as troubled youth. As a result, Denmead argues that white arts educators, in particular, must disinvest themselves from notions of creativity that enhance the profitability and power of whiteness. This move requires advocating ceding land and resources that have been acquired through the creative city discourse and committing to reframing culture‐led urban renewal in terms of the economic and creative flourishing of communities of color. 相似文献
5.
海洋生态系统的健康和安全,直接关系到全人类的健康和福祉。有效监测数据不足、科学决策信息缺失等因素一定程度上影响了海洋可持续发展目标(SDG 14)的顺利实施。地球大数据具备宏观、动态、客观监测能力,可在支撑SDG 14实现中起到重要作用。在中国科学院战略性先导科技专项(A类)的支持下,基于地球大数据相关技术和方法,我国已有效开展了海洋缺失数据集生产、目标本地化模型构建等具体实践。在以上分析基础上,文章提出了积极参与国际社会地球大数据共享,加强科技创新对SDG 14实现的驱动,深度参与联合国海洋治理计划等建议。 相似文献
6.
为了促进海洋经济发展,推动海洋强国建设,加快海洋科技创新、提高海洋全要素生产率成为新时期我国海洋经济发展重要驱动力。基于2007年—2017年我国11个沿海省市面板数据,运用面板向量自回归模型PVAR,分析海洋科技创新、海洋全要素与海洋经济发展的动态关系。研究结果表明:海洋科技创新和海洋全要素生产率存在自我增强机制;海洋科技创新与海洋全要素生产率存在双向促进关系,相互促进效果较小;在长期发展过程中,海洋经济发展对海洋全要素生产率的影响程度大于海洋科技创新;海洋经济发展的主要影响因素是海洋全要素生产率,海洋全要素生产率对海洋经济发展的促进作用比较明显。通过发挥自我增强机制的提升作用,提高海洋科技创新与海洋全要素生产率的相互促进效应,以创新驱动经济发展、以全要素生产率提升经济质量,促进我国海洋经济高质量发展,推动海洋强国建设。 相似文献
7.
There is a growing body of literature calling for work on the emerging role of smart cities as information hubs and knowledge repositories. This article reviews the existing smart city literature and integrates knowledge management perspectives to provide an overview of future research directions. By demonstrating the multi-stakeholder relationships involved in smart city development, it takes a crucial step towards looking into the role of knowledge management in future smart city research. Eighty-two peer-reviewed publications were analyzed covering smart city studies in various research domains. The systematic review identifies five different themes: strategy and vision, frameworks, enablers and inhibitors, citizen participation, and benefits. These themes form the basis for developing a future research agenda focused on knowledge sharing and co-learning among cities via three research directions: socio-technical approaches, knowledge sharing perspectives and organizational learning capabilities. The paper also proposes a series of knowledge-driven policy recommendations to contribute towards the UN Sustainable Development Goals. 相似文献
8.
Energy efficiency of public sector is an important issue in the context of smart cities due to the fact that buildings are the largest energy consumers, especially public buildings such as educational, health, government and other public institutions that have a large usage frequency. However, recent developments of machine learning within Big Data environment have not been exploited enough in this domain. This paper aims to answer the question of how to incorporate Big Data platform and machine learning into an intelligent system for managing energy efficiency of public sector as a substantial part of the smart city concept. Deep neural networks, Rpart regression tree and Random forest with variable reduction procedures were used to create prediction models of specific energy consumption of Croatian public sector buildings. The most accurate model was produced by Random forest method, and a comparison of important predictors extracted by all three methods has been conducted. The models could be implemented in the suggested intelligent system named MERIDA which integrates Big Data collection and predictive models of energy consumption for each energy source in public buildings, and enables their synergy into a managing platform for improving energy efficiency of the public sector within Big Data environment. The paper also discusses technological requirements for developing such a platform that could be used by public administration to plan reconstruction measures of public buildings, to reduce energy consumption and cost, as well as to connect such smart public buildings as part of smart cities. Such digital transformation of energy management can increase energy efficiency of public administration, its higher quality of service and healthier environment. 相似文献
9.
为促进我国海洋经济实现高质量发展,基于2006-2015年的省际面板数据,运用PVAR模型对海洋产业结构升级、海洋科技创新与海洋经济增长之间的动态关系进行实证分析,研究结果表明:海洋产业结构升级对海洋经济增长具有显著的影响,海洋经济增长对海洋科技创新具有显著的影响;从短期来看,海洋经济增长对海洋产业结构升级的正向效应不明显,从长期来看,海洋经济增长能够促进海洋产业结构的优化;海洋科技创新对海洋经济增长的正效应逐渐减弱;海洋产业结构升级对海洋经济增长的贡献率高于海洋科技创新对海洋经济增长的贡献率;海洋产业结构升级是海洋经济增长的格兰杰原因,海洋经济增长是海洋科技创新的格兰杰原因。 相似文献
10.