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   46168篇
  免费   15085篇
  国内免费   67篇
电工技术   911篇
技术理论   1篇
综合类   66篇
化学工业   18930篇
金属工艺   688篇
机械仪表   1169篇
建筑科学   1872篇
矿业工程   32篇
能源动力   1189篇
轻工业   7835篇
水利工程   336篇
石油天然气   70篇
武器工业   4篇
无线电   8219篇
一般工业技术   13262篇
冶金工业   1271篇
原子能技术   119篇
自动化技术   5346篇
  2023年   140篇
  2022年   188篇
  2021年   570篇
  2020年   1626篇
  2019年   3320篇
  2018年   3317篇
  2017年   3656篇
  2016年   4163篇
  2015年   4194篇
  2014年   4242篇
  2013年   5514篇
  2012年   3309篇
  2011年   3165篇
  2010年   3188篇
  2009年   3035篇
  2008年   2525篇
  2007年   2323篇
  2006年   2015篇
  2005年   1649篇
  2004年   1602篇
  2003年   1548篇
  2002年   1421篇
  2001年   1248篇
  2000年   1233篇
  1999年   603篇
  1998年   336篇
  1997年   203篇
  1996年   163篇
  1995年   106篇
  1994年   108篇
  1993年   85篇
  1992年   62篇
  1991年   54篇
  1990年   43篇
  1989年   45篇
  1988年   28篇
  1987年   26篇
  1986年   35篇
  1985年   28篇
  1984年   25篇
  1983年   19篇
  1981年   15篇
  1980年   17篇
  1979年   10篇
  1977年   14篇
  1976年   17篇
  1974年   9篇
  1973年   10篇
  1971年   7篇
  1970年   7篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
1.
Kuo  Shu-Chun  Chien  Tsair-Wei  Chou  Willy 《Scientometrics》2022,127(2):1191-1194
Scientometrics - The article published on 5 July 2021 is well-written and of interest. However, some improvements could be made, such as ten Tables/Figures can be shortened to highlight the focused...  相似文献   
2.
3.
Recent advances in three‐dimensional (3D) printing have enabled the fabrication of interesting structures which are not achievable using traditional fabrication approaches. The 3D printing of carbon microtube composite inks allows fabrication of conductive structures for practical applications in soft robotics and tissue engineering. However, it is challenging to achieve 3D printed structures from solution‐based composite inks, which requires an additional process to solidify the ink. Here, we introduce a wet 3D printing technique which uses a coagulation bath to fabricate carbon microtube composite structures. We show that through a facile nanogrooving approach which introduces cavitation and channels on carbon microtubes, enhanced interfacial interactions with a chitosan polymer matrix are achieved. Consequently, the mechanical properties of the 3D printed composites improve when nanogrooved carbon microtubes are used, compared to untreated microtubes. We show that by carefully controlling the coagulation bath, extrusion pressure, printing distance and printed line distance, we can 3D print composite lattices which are composed of well‐defined and separated printed lines. The conductive composite 3D structures with highly customised design presented in this work provide a suitable platform for applications ranging from soft robotics to smart tissue engineering scaffolds. © 2019 Society of Chemical Industry  相似文献   
4.
5.
The aim of this exploratory study has been to investigate the fire properties and environmental aspects of different upholstery material combinations, mainly for domestic applications. An analysis of the sustainability and circularity of selected textiles, along with lifecycle assessment, is used to qualitatively evaluate materials from an environmental perspective. The cone calorimeter was the primary tool used to screen 20 different material combinations from a fire performance perspective. It was found that textile covers of conventional fibres such as wool, cotton and polyester, can be improved by blending them with fire resistant speciality fibres. A new three‐dimensional web structure has been examined as an alternative padding material, showing preliminary promising fire properties with regard to ignition time, heat release rates and smoke production.  相似文献   
6.
Antimony triselenide (Sb2Se3) nanoflake-based nitrogen dioxide (NO2) sensors exhibit a progressive bifunctional gas-sensing performance, with a rapid alarm for hazardous highly concentrated gases, and an advanced memory-type function for low-concentration (<1 ppm) monitoring repeated under potentially fatal exposure. Rectangular and cuboid shaped Sb2Se3 nanoflakes, comprising van der Waals planes with large surface areas and covalent bond planes with small areas, can rapidly detect a wide range of NO2 gas concentrations from 0.1 to 100 ppm. These Sb2Se3 nanoflakes are found to be suitable for physisorption-based gas sensing owing to their anisotropic quasi-2D crystal structure with extremely enlarged van der Waals planes, where they are humidity-insensitive and consequently exhibit an extremely stable baseline current. The Sb2Se3 nanoflake sensor exhibits a room-temperature/low-voltage operation, which is noticeable owing to its low energy consumption and rapid response even under a NO2 gas flow of only 1 ppm. As a result, the Sb2Se3 nanoflake sensor is suitable for the development of a rapid alarm system. Furthermore, the persistent gas-sensing conductivity of the sensor with a slow decaying current can enable the development of a progressive memory-type sensor that retains the previous signal under irregular gas injection at low concentrations.  相似文献   
7.
8.
9.
10.
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