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   166219篇
  免费   3103篇
  国内免费   2954篇
教育   101022篇
科学研究   25104篇
各国文化   276篇
体育   9823篇
综合类   8984篇
文化理论   118篇
信息传播   26949篇
  2024年   16篇
  2023年   504篇
  2022年   1988篇
  2021年   3443篇
  2020年   4281篇
  2019年   1724篇
  2018年   1778篇
  2017年   2082篇
  2016年   2432篇
  2015年   4345篇
  2014年   11101篇
  2013年   12506篇
  2012年   14040篇
  2011年   14701篇
  2010年   10297篇
  2009年   9137篇
  2008年   10430篇
  2007年   11971篇
  2006年   12052篇
  2005年   10422篇
  2004年   8746篇
  2003年   7711篇
  2002年   6018篇
  2001年   4683篇
  2000年   2640篇
  1999年   1010篇
  1998年   634篇
  1997年   397篇
  1996年   363篇
  1995年   175篇
  1994年   177篇
  1993年   112篇
  1992年   95篇
  1991年   45篇
  1990年   32篇
  1989年   31篇
  1988年   6篇
  1987年   2篇
  1986年   1篇
  1985年   22篇
  1984年   16篇
  1983年   15篇
  1982年   21篇
  1981年   11篇
  1980年   6篇
  1979年   7篇
  1978年   13篇
  1977年   9篇
  1976年   10篇
  1957年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Nowadays assuring that search and recommendation systems are fair and do not apply discrimination among any kind of population has become of paramount importance. This is also highlighted by some of the sustainable development goals proposed by the United Nations. Those systems typically rely on machine learning algorithms that solve the classification task. Although the problem of fairness has been widely addressed in binary classification, unfortunately, the fairness of multi-class classification problem needs to be further investigated lacking well-established solutions. For the aforementioned reasons, in this paper, we present the Debiaser for Multiple Variables (DEMV), an approach able to mitigate unbalanced groups bias (i.e., bias caused by an unequal distribution of instances in the population) in both binary and multi-class classification problems with multiple sensitive variables. The proposed method is compared, under several conditions, with a set of well-established baselines using different categories of classifiers. At first we conduct a specific study to understand which is the best generation strategies and their impact on DEMV’s ability to improve fairness. Then, we evaluate our method on a heterogeneous set of datasets and we show how it overcomes the established algorithms of the literature in the multi-class classification setting and in the binary classification setting when more than two sensitive variables are involved. Finally, based on the conducted experiments, we discuss strengths and weaknesses of our method and of the other baselines.  相似文献   
2.
The massive number of Internet of Things (IoT) devices connected to the Internet is continuously increasing. The operations of these devices rely on consuming huge amounts of energy. Power limitation is a major issue hindering the operation of IoT applications and services. To improve operational visibility, Low-power devices which constitute IoT networks, drive the need for sustainable sources of energy to carry out their tasks for a prolonged period of time. Moreover, the means to ensure energy sustainability and QoS must consider the stochastic nature of the energy supplies and dynamic IoT environments. Artificial Intelligence (AI) enhanced protocols and algorithms are capable of predicting and forecasting demand as well as providing leverage at different stages of energy use to supply. AI will improve the efficiency of energy infrastructure and decrease waste in distributed energy systems, ensuring their long-term viability. In this paper, we conduct a survey to explore enhanced AI-based solutions to achieve energy sustainability in IoT applications. AI is relevant through the integration of various Machine Learning (ML) and Swarm Intelligence (SI) techniques in the design of existing protocols. ML mechanisms used in the literature include variously supervised and unsupervised learning methods as well as reinforcement learning (RL) solutions. The survey constitutes a complete guideline for readers who wish to get acquainted with recent development and research advances in AI-based energy sustainability in IoT Networks. The survey also explores the different open issues and challenges.  相似文献   
3.
Collaborations in funded teams are essential for understanding funded research and funding policies, although of high interest, are still not fully understood. This study aims to investigate directed collaboration patterns from the perspective of the knowledge flow, which is measured based on the academic age. To this end, we proposed a project-based team identification approach, which gives particular attention to funded teams. The method is applicable to other funding systems. Based on identified scientific teams, we detected recurring and significant subgraph patterns, known as network motifs, and under-represented patterns, known as anti-motifs. We found commonly occurred motifs and anti-motifs are remarkably characterized by different structures matching certain functions in knowledge exchanges. Collaboration patterns represented by motifs favor hierarchical structures, supporting intensive interactions across academic generations. Anti-motifs are more likely to show chain-like structures, hindering potentially various knowledge activities, and are thus seldom found in real collaboration networks. These findings provide new insights into the understanding of funded collaborations and also the funding system. Meanwhile, our findings are helpful for researchers, the public and policymakers to gain knowledge on research(ers) evolution, particularly in terms of primordial collaboration patterns.  相似文献   
4.
目的:研究夹层技术治疗楔状缺损的临床效果。方法:选择门诊确诊的66例需要修复楔状缺损的患牙,随机分为两组,对照组采用光固化树脂治疗,实验组采用夹层技术治疗,比较两组疗效。结果:治疗后6个月,实验组与对照组充填材料保留率差异无统计学意义(P>0.05);治疗后12个月,实验组充填材料保留率明显高于对照组且差异有统计学意义(P<0.05)。结论:夹层技术有助于楔状缺损的修复,临床可推广使用。  相似文献   
5.
唐宋词真迹今天已很少见,古籍文献特别是唐宋文献对唐宋词真迹的记载,可视为是唐宋词真迹保存的一种方式。文献记载的唐宋词真迹,在校勘、还原、鉴赏方面有一定的价值,如李煜?临江仙?词的创作场景,黄庭坚?念奴娇?词“爱听临风笛”之“笛”、?西江月?词“杯行到手莫留残”之“莫留残”,秦观?踏莎行?词“杜鹃声里斜阳暮”之“斜阳暮”等。词人词作真迹记载,不仅可以据之考察词作初创之面貌,还可以考察词人笔迹,了解其书法水平,并进一步考察词人人品、情趣。  相似文献   
6.
新冠肺炎疫情给高职院校图书馆带来了新问题、新挑战。为了创新高职院校图书馆的服务模式,南京城市职业学院联合国内其他13所高职院校开展了读者调查,在对调查结果进行分析的基础上,提出改善高职院校图书馆馆内服务、推进网站建设、使用社交媒体平台等建议。  相似文献   
7.
刘艳东 《天津教育》2021,(6):137-138
初中道德与法治课程要求结合理论知识和实践教学,不仅能对学生的知识结构体系进行构建,还能对学生正确的世界观、人生观和价值观等进行培养。对此,在初中的道德与法治课中,教师应该利用生活化教学对学生开展实际的教学和探索,使学生能够在实际生活中通过对所学知识的运用,高效解决生活中的问题。  相似文献   
8.
随着时代的进步与发展,小学科学早已被学校当成培养学生创新能力、创新思维以及动手能力的一门课程。尤其是把信息技术与小学科学整合起来,既能使教学方式更加灵活、多样,内容更加丰富、充实,也能改变传统小学科学教学模式,激发学生兴趣,唤醒学生的创新意识,为新时代小学生全面发展奠定基础。  相似文献   
9.
思想政治教育工作是学校教育任务的重要组成部分,它关系着中小学生人格的塑造、价值观念的构建以及行为习惯的养成,所以这一工作不能忽视。中小学阶段是学生成长的关键时期,这一阶段形成的学习习惯和思想认知将会影响学生一生。学校要采用科学、高效的方法来开展这一工作,以使中小学生拥有良好的综合素养,今后为祖国建设而努力。  相似文献   
10.
从道路条件、天气条件和设施条件3个方面选取18个影响因素,基于DAMATEL方法,建立直接影响矩阵并规范化,获得综合影响矩阵,得到三层次风雨耦合作用下的城市道路风险评估体系,结合模糊综合评价以及层次分析法确定各级评价指标的权重,建立了一个相对完整的评价体系,并将其应用于当地的风险评估中,为当地的交通管理控制以及降低行车风险提供了一定的理论参考。  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