首页 | 官方网站   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   305416篇
  免费   4843篇
  国内免费   937篇
工业技术   311196篇
  2021年   2553篇
  2019年   2358篇
  2018年   4464篇
  2017年   4303篇
  2016年   4655篇
  2015年   3138篇
  2014年   5004篇
  2013年   13476篇
  2012年   7953篇
  2011年   10364篇
  2010年   8521篇
  2009年   9597篇
  2008年   10007篇
  2007年   9791篇
  2006年   8553篇
  2005年   7873篇
  2004年   7207篇
  2003年   6918篇
  2002年   6611篇
  2001年   6361篇
  2000年   5943篇
  1999年   6179篇
  1998年   16054篇
  1997年   11726篇
  1996年   8900篇
  1995年   6871篇
  1994年   6188篇
  1993年   6038篇
  1992年   4531篇
  1991年   4514篇
  1990年   4329篇
  1989年   4329篇
  1988年   4276篇
  1987年   3642篇
  1986年   3664篇
  1985年   4250篇
  1984年   4042篇
  1983年   3680篇
  1982年   3470篇
  1981年   3633篇
  1980年   3502篇
  1979年   3407篇
  1978年   3483篇
  1977年   4039篇
  1976年   5341篇
  1975年   3175篇
  1974年   3027篇
  1973年   3069篇
  1972年   2651篇
  1971年   2462篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Journal of Low Temperature Physics - This study modeled and investigated the magnetocaloric effect in Ni2MnGa Heusler alloy characterized by its magnetic entropy change (ΔSm) and its...  相似文献   
2.
Anzaldo  Alexis  Andrade  Ángel G. 《Wireless Networks》2022,28(8):3613-3620
Wireless Networks - Beyond five generation (B5G) systems will demand strict and heterogeneous service requirements for the emerging applications. One solution to meet these demands is the dense...  相似文献   
3.
Journal of Materials Science: Materials in Electronics - A mixed solution of 2-aminopyridine and succinic acid, with a 1:1 molar ratio, was kept at room temperature to develop a 2-aminopridinium...  相似文献   
4.
Duparc  Estelle  Möller  Frederik  Jussen  Ilka  Stachon  Maleen  Algac  Sükran  Otto  Boris 《Electronic Markets》2022,32(2):727-745
Electronic Markets - The open-source paradigm offers a plethora of opportunities for innovative business models (BMs) as the underlying codebase of the technology is accessible and extendable by...  相似文献   
5.
Journal of Materials Science - The application of ceramics in advanced functional applications often requires thicknesses below a few hundred micrometers, rendering an assessment of the...  相似文献   
6.
Multimedia Tools and Applications - The quality and quantity of agricultural products are significantly affected by plant diseases. The plant diseases could be mitigated if identified at an early...  相似文献   
7.
8.
Theoretical Foundations of Chemical Engineering - The reaction of nickel(II) hydroxide and a mixed ammonia–carbonate solution to form nickel(II) aqua–ammonia complexes is studied in the...  相似文献   
9.

Two promising technologies cosidered for the Beyond 5G networks are the terahertz and nano-technologies. Besides other possible application areas they hold the commitment to numerous new nano-scale solutions in the biomedical field. Nano-technology, as the name implies, examines the construction and design of nano-sized materials. These two interconnected emerging technologies have the potential to find application in quite many areas, one of the most importan being healthcare. This overview paper discusses the specifics of these technologies, their most important characteristics and introduces some of the trends for their application in the healthcare sector. In the first section terahertz frequency radio waves and their specific properties depending on the surrounding environment are discussed, followed by an introduction to nano-scale communications. Terahertz waves mandate the use of nano-scale antennas, which in turn brings us to the concept of nano-scale nodes. Nano-scale nodes are units that can perform the most basic functions of nano-machines and inter-nano-machine communications, which allow distributed nano-machines to perform more complex functions. Beyond 5G the development of these nano-communications is expected to lead to the emergence of new complex network systems. In the second part of this paper the paradigms of the Internet of Nano Things, molecular commnications and the Internet of Bio-Nano Things are discussed followed by details on their integration in healthcare related applications. The main goal of the article is to provide an introduction to these intriguing issues discussing advanced nano-technology enablers for Beyond 5G networks such as terahertz and molecular communications, nano-communications between nano-machines and the Internet of Bio-Nano-Things in light of health related applications.

  相似文献   
10.
Chemistry and Technology of Fuels and Oils - The review examines biomass of animal origin in terms of a potential renewable raw material for obtaining CO2-neutral fuel unaffecting the carbon...  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-23

京公网安备 11010802026262号