全文获取类型
收费全文 | 1573947篇 |
免费 | 31878篇 |
国内免费 | 8930篇 |
专业分类
电工技术 | 36709篇 |
技术理论 | 7篇 |
综合类 | 9555篇 |
化学工业 | 264802篇 |
金属工艺 | 67077篇 |
机械仪表 | 46555篇 |
建筑科学 | 47797篇 |
矿业工程 | 13091篇 |
能源动力 | 51335篇 |
轻工业 | 119127篇 |
水利工程 | 16339篇 |
石油天然气 | 39722篇 |
武器工业 | 611篇 |
无线电 | 201841篇 |
一般工业技术 | 293761篇 |
冶金工业 | 195532篇 |
原子能技术 | 34847篇 |
自动化技术 | 176047篇 |
出版年
2021年 | 16592篇 |
2020年 | 13458篇 |
2019年 | 15908篇 |
2018年 | 18579篇 |
2017年 | 18143篇 |
2016年 | 23495篇 |
2015年 | 19483篇 |
2014年 | 31283篇 |
2013年 | 90983篇 |
2012年 | 40221篇 |
2011年 | 53954篇 |
2010年 | 46750篇 |
2009年 | 54488篇 |
2008年 | 49583篇 |
2007年 | 46802篇 |
2006年 | 48282篇 |
2005年 | 42912篇 |
2004年 | 44150篇 |
2003年 | 43269篇 |
2002年 | 40301篇 |
2001年 | 37104篇 |
2000年 | 34669篇 |
1999年 | 34851篇 |
1998年 | 53099篇 |
1997年 | 43677篇 |
1996年 | 37241篇 |
1995年 | 32893篇 |
1994年 | 30411篇 |
1993年 | 30225篇 |
1992年 | 26377篇 |
1991年 | 23504篇 |
1990年 | 23841篇 |
1989年 | 22749篇 |
1988年 | 21263篇 |
1987年 | 19529篇 |
1986年 | 18927篇 |
1985年 | 22211篇 |
1984年 | 22181篇 |
1983年 | 20114篇 |
1982年 | 19155篇 |
1981年 | 19296篇 |
1980年 | 17924篇 |
1979年 | 18350篇 |
1978年 | 17664篇 |
1977年 | 17820篇 |
1976年 | 19457篇 |
1975年 | 15841篇 |
1974年 | 15342篇 |
1973年 | 15462篇 |
1972年 | 12997篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
71.
Volkov K. N. Emelyanov V. N. Karpenko A. G. 《Journal of Engineering Physics and Thermophysics》2022,95(1):80-89
Journal of Engineering Physics and Thermophysics - A simulation of the vibroacoustic processes proceeding in a long pipe with an obstacle in the form of a circular cylinder, in which a fluid flows,... 相似文献
72.
Radiochemistry - The sorption extraction of Pu and Am from nitric acid simulation solutions were studied on a solid extractant (TVEX) AXIONIT MND 40T in a static mode. It is shown that the... 相似文献
73.
74.
75.
76.
Cybernetics and Systems Analysis - A new information software technology has been created, which is implemented in a software package and is destined to perform a wide, easily supplemented set of... 相似文献
77.
Kathleen T. Lauser Amy L. Rueter Michelle A. Calabrese 《American Institute of Chemical Engineers》2022,68(12):e17850
While protein medications are promising for treatment of cancer and autoimmune diseases, challenges persist in terms of development and injection stability of high-concentration formulations. Here, the extensional flow properties of protein-excipient solutions are examined via dripping-onto-substrate extensional rheology, using a model ovalbumin (OVA) protein and biocompatible excipients polysorbate 20 (PS20) and 80 (PS80). Despite similar PS structures, differences in extensional flow are observed based on PS identity in two regimes: at moderate total concentrations where surface tension differences drive changes in extensional flow behavior, and at small PS:OVA ratios, which impact the onset of weakly elastic flow behavior. Undesirable elasticity is observed in ultra-concentrated formulations, independent of PS identity; higher PS contents are required to observe these effects than in analogous polymeric excipient solutions. These studies reveal novel extensional flow behaviors in protein-excipient solutions, and provide a straightforward methodology for assessing the extensional flow stability of new protein-excipient formulations. 相似文献
78.
Hydrogenation of CO2 to Hydrocarbons over Zirconia-Supported Cobalt Catalyst Promoted with Potassium
Catalysis Letters - The purpose of this study was to investigate the promotive effect of potassium on the catalytic performance and properties of Co/ZrO2 catalysts during hydrogenation of CO2 to... 相似文献
79.
El-Shafiey Mohamed G. Hagag Ahmed El-Dahshan El-Sayed A. Ismail Manal A. 《Multimedia Tools and Applications》2022,81(13):18155-18179
Multimedia Tools and Applications - Nowadays, heart diseases are significantly contributing to deaths all over the world. Thus, heart-disease prediction has garnered considerable attention in the... 相似文献
80.
Zagidullin S. Kh. Dolganov V. L. Lozhkin I. G. 《Chemical and Petroleum Engineering》2022,57(9-10):765-769
Chemical and Petroleum Engineering - The hydrodynamics of oxidation towers used for bitumen production were studied using a model tower having transparent walls. Experiments were carried out in two... 相似文献