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   14663篇
  免费   1259篇
  国内免费   413篇
电工技术   595篇
综合类   596篇
化学工业   3229篇
金属工艺   470篇
机械仪表   565篇
建筑科学   803篇
矿业工程   238篇
能源动力   531篇
轻工业   1907篇
水利工程   222篇
石油天然气   308篇
武器工业   39篇
无线电   1291篇
一般工业技术   2032篇
冶金工业   961篇
原子能技术   169篇
自动化技术   2379篇
  2024年   36篇
  2023年   165篇
  2022年   448篇
  2021年   615篇
  2020年   447篇
  2019年   479篇
  2018年   522篇
  2017年   509篇
  2016年   553篇
  2015年   545篇
  2014年   633篇
  2013年   1036篇
  2012年   917篇
  2011年   1028篇
  2010年   840篇
  2009年   777篇
  2008年   791篇
  2007年   711篇
  2006年   580篇
  2005年   442篇
  2004年   453篇
  2003年   559篇
  2002年   668篇
  2001年   561篇
  2000年   277篇
  1999年   204篇
  1998年   284篇
  1997年   222篇
  1996年   154篇
  1995年   126篇
  1994年   98篇
  1993年   103篇
  1992年   55篇
  1991年   49篇
  1990年   59篇
  1989年   52篇
  1988年   24篇
  1987年   36篇
  1986年   28篇
  1985年   29篇
  1984年   34篇
  1983年   29篇
  1982年   22篇
  1981年   9篇
  1980年   27篇
  1979年   10篇
  1978年   12篇
  1977年   17篇
  1976年   29篇
  1975年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Osteosarcoma (OS) is a rare condition with very poor prognosis in a metastatic setting. Basic research has enabled a better understanding of OS pathogenesis and the discovery of new potential therapeutic targets. Phase I and II clinical trials are already ongoing, with some promising results for these patients. This article reviews OS pathogenesis and new potential therapeutic targets.  相似文献   
3.
A recent development in tactile technology enables an improvement in the appreciation of the visual arts for people with visual impairment (PVI). The tactile sense, in conjunction with, or a possibly as an alternative to, the auditory sense, would allow PVIs to approach artwork in a more self‐driven and engaging way that would be difficult to achieve with just an auditory stimulus. Tactile colour pictograms (TCPs), which are raised geometric patterns, are ideographic characters that are designed to enable PVIs to identify colours and interpret information by touch. In this article, three TCPs are introduced to code colours in the Munsell colour system. Each colour pattern consists of a basic cell size of 10 mm × 10 mm to represent the patterns consistently in terms of regular shape. Each TCP consists of basic geometric patterns that are combined to create primary, secondary, and tertiary colour pictograms of shapes indicating colour hue, intensity and lightness. Each TCP represents 29 colours including six hues; they were then further expanded to represent 53 colours. Two of them did not increase the cell size, the other increased the cell size 1.5 times for some colours, such as yellow‐orange, yellow, blue, and blue‐purple. Our proposed TCPs use a slightly larger cell size compared to most tactile patterns currently used to indicate colour, but code for more colours. With user experience and identification tests, conducted with 23 visually impaired adults, the effectiveness of the TCPs suggests that they were helpful for the participants.  相似文献   
4.
An alternative for reducing emissions from marine fuel is to blend bio-oil from lignocellulose non-edible feedstocks to diesel fossil fuels. Phase diagrams of the ternary systems were built to represent the transition from heterogeneous regions to homogeneous regions. Four homogeneous blends of bio-oil of eucalyptus-bioethanol-marine gasoil were experimentally characterized with respect to the most important fuel parameters for marine engines: water content, flash point, low heating value, viscosity, and acidity. Blends with closer properties to marine gasoil replacement, lower costs, and environmental impacts should be tested for large engines.  相似文献   
5.
6.
Polymer Bulletin - In this study, we synthesized a new ion-imprinted polymer (IIP) based on introduction of amidoxime groups in acrylonitrile, complexation with Cd2+ ions and polymerization with...  相似文献   
7.
Debittered trub (brewing waste) is an important source of protein source (70.26%). Trub and whey protein were used for 5% protein enrichment of ice cream frozen by liquid nitrogen. Three formulations were elaborated: ice cream standard (ICS), ice cream with whey protein (ICW) and ice cream with trub (ICT). Chemical composition, rheological properties, texture, overrun, melting rate, scanning electron microscopy and a sensorial test were performed. Results showed that ICT presented a higher viscosity, obtained on the upward curve up to 6.76 Pa s−1, consistency index (22.96 (Pa s−1)n), hysteresis area (140.40 mPa s−1) and hardness (31113.33 g) but a lower melting rate (0.38 g min−1), overrun (13.92%) and sensorial acceptability than the other formulations. The addition of trub debittered for protein enrichment improved ice cream properties and demonstrated that it could be used as a food ingredient.  相似文献   
8.
Food Analytical Methods - The habanero pepper (Capsicum chinense Jacq.) is very aromatic and is the hottest pepper in the world. In this study, a headspace solid-phase microextraction/gas...  相似文献   
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