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   807篇
  免费   85篇
  国内免费   9篇
电工技术   19篇
综合类   1篇
化学工业   309篇
金属工艺   10篇
机械仪表   11篇
建筑科学   17篇
能源动力   32篇
轻工业   155篇
水利工程   9篇
石油天然气   14篇
无线电   60篇
一般工业技术   142篇
冶金工业   13篇
原子能技术   7篇
自动化技术   102篇
  2024年   1篇
  2023年   23篇
  2022年   51篇
  2021年   82篇
  2020年   55篇
  2019年   78篇
  2018年   68篇
  2017年   81篇
  2016年   72篇
  2015年   44篇
  2014年   57篇
  2013年   74篇
  2012年   42篇
  2011年   45篇
  2010年   27篇
  2009年   28篇
  2008年   15篇
  2007年   12篇
  2006年   11篇
  2005年   5篇
  2004年   5篇
  2003年   3篇
  2000年   1篇
  1999年   3篇
  1997年   1篇
  1996年   4篇
  1995年   2篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1987年   1篇
  1984年   1篇
  1982年   2篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
排序方式: 共有901条查询结果,搜索用时 31 毫秒
31.
Ni-based/SBA-15 catalysts, were promoted by 3wt % of samaria (Sm2O3), Yttria (Y2O3) and Zirconia (ZrO2), by two-solvent impregnation method. The catalysts characterization was performed by N2 adsorption–desorption, X-ray Diffraction (XRD), X-ray Fluorescence (XRF), High Resolution Transmission Electron Microscopy (HRTEM), Field Emission Electron Scanning Microscopy (FESEM), Temperature Programmed Oxidation/Reduction (TPO/TPR) and NH3-Temperature Programmed Desorption (NH3-TPD) techniques. Then, evaluated by CO2/methane reforming.The CO2/methane reforming outcomes revealed that samaria-promoted catalyst showed excellent activity, stability and cock resistance, while yttria-promoted catalyst just illustrated good activity at high temperature and zirconia-promoted catalyst didn't show any modification in catalytic performance in comparison to Ni-based catalyst with no promoter. Samaria-promoted TEM and TPR analysis, indicated adding samaria improved the NiO particles interaction with SBA-15 support pores wall and NiO dispersion. The TPO analysis displayed that coke deposition in samaria-promoted sample after 12 h reaction is less than yttria-promoted during stream of 5 h. Also, it is suggested that for samaria containing catalyst, cock deposition occurred on the support. Therefore, nickel active sites were preserved for time on stream of 12 h, which is the main reason for samaria-promoted catalyst superior stability than other's.  相似文献   
32.
33.
Multimedia Tools and Applications - Auto understanding of human activities in video is an increasing necessity in some application realms. The existing methods for human’s activity...  相似文献   
34.
Multimedia Tools and Applications - Synchronization of different Chaotic dynamical systems is one of the main issues in engineering which has a lot of applications in applied sciences like secure...  相似文献   
35.
36.
37.
38.
Non-small cell lung cancer (NSCLC) patients with sensitizing mutations in the exons 18–21 of the epithelial growth factor receptor (EGFR) gene show increased kinase activity of EGFR. Hence, tyrosine kinase inhibitors (TKIs) such as erlotinib (ETB) have commonly been used as the second line therapeutic option for the treatment of metastatic NSCLC. While the ETB is available as an oral dosage form, the local delivery of this TKI to the diseased cells of the lung may ameliorate its therapeutic impacts. In the current study, we report on the development of ETB-loaded solid lipid nanoparticle (SLN) based formulation of dry powder inhaler (ETB-SLN DPI). ETB-SLNs were formulated using designated amount of compritol/poloxamer 407. The engineered ETB-SLNs showed sub-100?nm spherical shape with an encapsulation efficiency of 78.21%. MTT assay and DAPI staining revealed that the ETB-SLNs enhanced the cytotoxicity of cargo drug molecules in the human alveolar adenocarcinoma epithelial A549 cells as a model for NSCLC. To attain the ETB-SLN DPI, the ETB-SLNs were efficiently spray dried into microparticles (1–5?μm) along with mannitol. The ETB-SLN DPI powder displayed suitable flowability and aerodynamic traits. The Carr's Index, Hausner ratio and Next Generation Impactor (NGI) analyses confirmed deep inhalation pattern of the formulation. Based on these findings, we propose the ETB-SLN DPI as a promising treatment modality for the NSCLC patients.  相似文献   
39.
40.
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