全文获取类型
收费全文 | 14117篇 |
免费 | 302篇 |
国内免费 | 319篇 |
专业分类
教育 | 7683篇 |
科学研究 | 2876篇 |
各国文化 | 36篇 |
体育 | 895篇 |
综合类 | 734篇 |
文化理论 | 76篇 |
信息传播 | 2438篇 |
出版年
2024年 | 8篇 |
2023年 | 27篇 |
2022年 | 188篇 |
2021年 | 424篇 |
2020年 | 354篇 |
2019年 | 160篇 |
2018年 | 173篇 |
2017年 | 204篇 |
2016年 | 162篇 |
2015年 | 482篇 |
2014年 | 762篇 |
2013年 | 923篇 |
2012年 | 1099篇 |
2011年 | 1177篇 |
2010年 | 1117篇 |
2009年 | 988篇 |
2008年 | 917篇 |
2007年 | 1028篇 |
2006年 | 951篇 |
2005年 | 794篇 |
2004年 | 474篇 |
2003年 | 414篇 |
2002年 | 401篇 |
2001年 | 385篇 |
2000年 | 259篇 |
1999年 | 254篇 |
1998年 | 158篇 |
1997年 | 121篇 |
1996年 | 103篇 |
1995年 | 48篇 |
1994年 | 48篇 |
1993年 | 25篇 |
1992年 | 33篇 |
1991年 | 22篇 |
1990年 | 5篇 |
1989年 | 12篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1957年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
协同办公利用工作流技术,实现工作审批和流程管理,在高校的信息化工作中起到重要作用,规范工作流程、提高工作效率、实现数据信息的共享、为领导科学决策提供支撑等.以北京联合大学为例,分别从校级办公应用、院级办公应用、信息化防控体系构建等方面,具体论述协同办公技术在高校中的实际应用现状及效果. 相似文献
992.
993.
论数字图书馆知识管理工具 总被引:3,自引:0,他引:3
本文从知识分类、组织管理、网站建设、数据库连接、一站式检索、知识咨询服务等方面对知识管理工具在数字图书馆的知识生产、知识编码与提炼、知识传输管理以及知识服务中发挥的重大作用进行了阐述,并介绍了数字图书馆知识管理流程及其工具的应用,展望知识管理工具的发展方向。 相似文献
994.
电子文档长期保存格式分析 总被引:1,自引:0,他引:1
文章从分析目前文档格式现状入手,在综合国内外研究成果的基础上提出长期保存文档格式选择的标准,并对PDF格式与基于XML的格式进行了比较,认为基于XML的格式更适合作为长期保存文档的格式。 相似文献
995.
Jiale Xia Yumeng Xue Bo Lei Lingling Xu Mingzi Sun Na Li Hongyang Zhao Min Wang Meng Luo Chao Zhang Bolong Huang Yaping Du Chun-Hua Yan 《国家科学评论(英文版)》2021,(7):170-179
2D nanomaterials generally exhibit enhanced physiochemical and biological functions in biomedical applications due to their high surface-to-volume ratio and sur... 相似文献
996.
通过设置问题情境引导学生判断主张、寻找事实与证据、科学推理及探究学习,论证主张“基因决定生物性状”的正确性,采用小组合作学习尝试建构“中心法则”模型,训练科学思维,形成生命观念,提升生物学核心素养. 相似文献
997.
赵啸海 《广西广播电视大学学报》2012,(1):14-17,41
德国远程教育有一百多年的历史,形成了自己独特的发展模式,表现在注重面授教学的混合式教学模式、严谨的立法保障、严格的质量监控以及卓有成效的应用拓展,其成熟的发展经验能给我们带来一些启示 相似文献
998.
Weijie Zhao 《国家科学评论(英文版)》2022,9(8)
‘We aim to have CO2 emissions peak before 2030 and achieve carbon neutrality before 2060,’ President Xi Jinping so declared at the General Debate of the 75th United Nations General Assembly on 22 September 2020. More than 130 countries globally have proposed their own carbon neutrality goals by 2050 or 2060. Thus, carbon neutrality is a collective effort of human societies to cope with the climate crisis. If all countries could follow their own plans and reach carbon neutrality in a few decades, we may have a chance to control global warming within 1.5 or 2oC, confining climate change to a relatively safe zone. As a developing country with a large population, high coal consumption and large manufacturing industries, can China achieve the huge task of societal transformation that will enable carbon peaking and carbon neutrality within the next four decades? How will China transform traditional power generation and manufacturing industries, as well as create new technologies for carbon capture and storage? In this panel discussion chaired by Prof. Xinhe Bao, a scientist of energy and chemistry, top experts gathered to discuss the challenges and potential solutions, outlining the coming ‘green industrial revolution’. Huiming Cheng Professor, Institute of Metal Research, Chinese Academy of Sciences; Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences Zhengtang Guo Professor, Institute of Geology and Geophysics, Chinese Academy of Sciences Yaling He Professor, School of Energy and Power Engineering, Xi’an Jiaotong University Zheng Li Professor, Institute of Climate Change and Sustainable Development, Tsinghua University Minggao Ouyang Professor, School of Vehicle and Mobility, Tsinghua University Zhengrong Shi Professor, College of Energy and Mechanical Engineering, Shanghai University of Electric Power Zaiku Xie Professor, China Petroleum and Chemical Corporation (SINOPEC) Xinhe Bao (Chair) Professor, University of Science and Technology of China, and Dalian Institute of Chemical Physics, Chinese Academy of Sciences Bao: Today we have experts from different disciplines related to energy to talk about the issues of carbon peaking and carbon neutrality in China. Since September 2020, China has initiated many plans and strategies for achieving these goals. I would like to invite Prof. Li to introduce the background and significance of achieving carbon neutrality in China. Li : There is now a global consensus on the crisis of climate change. It is a challenge for all human societies. Carbon peaking and carbon neutrality are the solutions targeting the source of climate change—the emission of greenhouse gases. Most countries have promised to achieve carbon neutrality, and from the European Green Deal to China''s initiatives, the goal is not just
From the European Green Deal to China''s initiatives, the goal is not just to reduce carbon emissions, but also to initiate a ‘green industrial revolution’.—Zheng Lito reduce carbon emissions, but also to initiate a ‘green industrial revolution’ and lead human society to a new path that does not depend upon fossil energies. Going green has become a global trend. If China wishes to achieve sustainable development in the future, the only wise choice is to follow, or even lead this trend. So, we can see that setting the carbon neutrality goal is a well-thought-out strategic decision of the Chinese government.Almost all countries aim to achieve carbon neutrality, but each country has its own energy structure and development stage, so the degree of difficulty in achieving these goals is different. In fact, western developed countries have already reached peak carbon emissions. Europe and the US reached their peak in the 1980s and 2005, thus have ∼70 and 45 years to achieve neutrality by 2050, respectively. But China is still developing and has not reached its peak. Moreover, our industrial structure is biased towards heavy industry and our energy structure is biased towards coal use, so it is a great challenge for China to reach its peak by 2030 and achieve neutrality by 2060.Furthermore, not all countries are equally responsible for the current climate crisis. Developing countries have not emitted as much carbon, historically, as developed countries, and they also have the right to develop. At the Glasgow Climate Change Conference in 2021, developed countries proposed setting 1.5°C, instead of 2°C, as the only limit for temperature rise, and proposed that all nations should ‘phase out’ the usage of coal. After negotiations and compromises, the final document kept the 2°C limit set by the 2015 Paris Agreement, and pointed out that we should keep 1.5°C within reach. It also replaced the term ‘phase out’ with ‘phase down’ regarding coal use.To summarize, to achieve carbon neutrality and to create a green society is a significant task for the entire world, benefiting all humanity. Bao: To achieve carbon neutrality, what can we learn from other countries? Li : There was a study of Net-Zero America in the US, which presented six different future scenarios under different energy structures and electrification levels. The study proposed several major strategies that we can learn from. First, the electrification of energy consumption end users is the most important approach for decreasing energy consumption and carbon emissions. Second, to achieve carbon neutrality, non-fossil energy will definitely need to become the primary energy source, but some fossil energy has to be maintained for the stability of the power grid. Thus, keeping a proper ratio of fossil and non-fossil sources is important. Third, carbon capture and storage (CCS) technologies must be simultaneously developed to neutralize the carbon emitted from fossil fuel usage. Actually, the CCS capacity is the decisive factor in determining the amount of fossil fuels we can use. Guo: Because of different social conditions, the challenges facing each country are also different. Many strategies cannot be simply transferred from other countries to China. I think there are three things we can learn from advanced countries. First, we can adopt advanced green technologies already implemented abroad. Second, we can learn how to build a low-carbon culture from European countries. In many European countries, almost everybody accepts the low-carbon concept, preferring to buy small-engined cars and saving energy and resources in their daily lives. That is what we can strive for. Third, in addition to the comprehensive national policies we have initiated, we should make customized plans of carbon neutrality for each province, each city and each town, in accordance with the unique regional conditions of natural resources, development level and energy structure. Cheng: When we talk about carbon neutrality, we mostly focus on energy and resource, but in Europe, people also consider industry, architecture, transportation, agriculture, ecology and many other sectors of society. I think this systematic approach is what we can learn from. Bao: China is also considering these various approaches. But as energy-related researchers, we may hear more about topics on energy. But you are right that carbon neutrality is a systems problem. Maybe we should first sort out the major topics we could talk about. He: I think there are three major aspects: first, emissions reduction in energy generation, namely, gradually replacing fossil fuels with natural gas and renewable energies; second, green transformation of energy consumption, such as the transformation of industries and transportation; third, development of CCS technologies. Moreover, both energy generation and energy consumption sectors are calling for breakthroughs in energy storage technologies. 相似文献
999.
王昭 《黄石理工学院学报(人文社科版)》2010,27(3):21-23,34
20世纪90年代兴起的个人化写作方式是中国文学史中的一道亮丽风景。文章通过对个人化写作特质的观照,描摹了个人化写作的独特风貌,即:写作内容的世俗化、写作对象的"小资"化、写作空间的都市化、写作语言的生活化。 相似文献
1000.
由于分层空时码具有良好的频谱利用率和码速率,因此WIFI无线局域网系统中采用分层空时码.排序串行干扰信号检测算法具有良好的检测性能,但其译码复杂度很高.并行干扰消除算法虽然译码简单但其检测性能比较差.本文在并行干扰消除算法的基础上,提出了一种具有低复杂度且检测性能优良的算法.在WIFI无线信道A、B、F模型条件下仿真,结果表明,该算法具有良好的检测性能且复杂度最低. 相似文献