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   33264篇
  免费   2281篇
  国内免费   99篇
电工技术   490篇
综合类   51篇
化学工业   7057篇
金属工艺   1228篇
机械仪表   1940篇
建筑科学   741篇
矿业工程   11篇
能源动力   1383篇
轻工业   2851篇
水利工程   131篇
石油天然气   19篇
无线电   5851篇
一般工业技术   7160篇
冶金工业   2465篇
原子能技术   463篇
自动化技术   3803篇
  2023年   382篇
  2022年   212篇
  2021年   1016篇
  2020年   745篇
  2019年   791篇
  2018年   1086篇
  2017年   1006篇
  2016年   1224篇
  2015年   971篇
  2014年   1478篇
  2013年   2227篇
  2012年   2163篇
  2011年   2658篇
  2010年   2024篇
  2009年   2068篇
  2008年   1881篇
  2007年   1452篇
  2006年   1320篇
  2005年   1119篇
  2004年   1039篇
  2003年   930篇
  2002年   902篇
  2001年   774篇
  2000年   675篇
  1999年   668篇
  1998年   1074篇
  1997年   691篇
  1996年   563篇
  1995年   423篇
  1994年   294篇
  1993年   240篇
  1992年   183篇
  1991年   162篇
  1990年   144篇
  1989年   147篇
  1988年   114篇
  1987年   108篇
  1986年   102篇
  1985年   78篇
  1984年   63篇
  1983年   57篇
  1982年   39篇
  1981年   48篇
  1980年   50篇
  1979年   25篇
  1978年   16篇
  1977年   39篇
  1976年   59篇
  1975年   27篇
  1974年   18篇
排序方式: 共有10000条查询结果,搜索用时 324 毫秒
1.
Food Science and Biotechnology - Various hilling materials (rice hulls, pine sawdust, and perlite) were compared to produce sprout vegetables using beach silvertop (Glehnia littoralis Fr. Schm. ex...  相似文献   
2.
International Journal of Information Security - Machine learning techniques have been widely used and shown remarkable performance in various fields. Along with the widespread utilization of...  相似文献   
3.
Silicon - Quadruple gate FinFET is a promising candidate among other multi-gate MOS devices due to it’s better scalability and higher short channel effect suppression capability in advanced...  相似文献   
4.
Thyromimetics, whose physicochemical characteristics are analog to thyroid hormones (THs) and their derivatives, are promising candidates as novel therapeutics for neurodegenerative and metabolic pathologies. In particular, sobetirome (GC-1), one of the initial halogen-free thyromimetics, and newly synthesized IS25 and TG68, with optimized ADME-Tox profile, have recently attracted attention owing to their superior therapeutic benefits, selectivity, and enhanced permeability. Here, we further explored the functional capabilities of these thyromimetics to inhibit transthyretin (TTR) amyloidosis. TTR is a homotetrameric transporter protein for THs, yet it is also responsible for severe amyloid fibril formation, which is facilitated by tetramer dissociation into non-native monomers. By combining nuclear magnetic resonance (NMR) spectroscopy, computational simulation, and biochemical assays, we found that GC-1 and newly designed diphenyl-methane-based thyromimetics, namely IS25 and TG68, are TTR stabilizers and efficient suppressors of TTR aggregation. Based on these observations, we propose the novel potential of thyromimetics as a multi-functional therapeutic molecule for TTR-related pathologies, including neurodegenerative diseases.  相似文献   
5.
6.
7.
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   
8.
The germline carrier of the BRCA1 pathogenic mutation has been well proven to confer an increased risk of breast and ovarian cancer. Despite BRCA1 biallelic pathogenic mutations being extremely rare, they have been reported to be embryonically lethal or to cause Fanconi anemia (FA). Here we describe a patient who was a 48-year-old female identified with biallelic pathogenic mutations of the BRCA1 gene, with no or very subtle FA-features. She was diagnosed with ovarian cancer and breast cancer at the ages of 43 and 44 and had a strong family history of breast and gynecological cancers.  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