全文获取类型
收费全文 | 195766篇 |
免费 | 2374篇 |
国内免费 | 628篇 |
专业分类
电工技术 | 4015篇 |
综合类 | 123篇 |
化学工业 | 25789篇 |
金属工艺 | 7482篇 |
机械仪表 | 5416篇 |
建筑科学 | 3983篇 |
矿业工程 | 746篇 |
能源动力 | 4622篇 |
轻工业 | 14103篇 |
水利工程 | 1687篇 |
石油天然气 | 2782篇 |
武器工业 | 7篇 |
无线电 | 27235篇 |
一般工业技术 | 37204篇 |
冶金工业 | 45374篇 |
原子能技术 | 3560篇 |
自动化技术 | 14640篇 |
出版年
2021年 | 1204篇 |
2019年 | 1282篇 |
2018年 | 2125篇 |
2017年 | 2104篇 |
2016年 | 2173篇 |
2015年 | 1494篇 |
2014年 | 2615篇 |
2013年 | 7950篇 |
2012年 | 4463篇 |
2011年 | 6111篇 |
2010年 | 4930篇 |
2009年 | 5771篇 |
2008年 | 6145篇 |
2007年 | 6195篇 |
2006年 | 5635篇 |
2005年 | 5303篇 |
2004年 | 5249篇 |
2003年 | 5088篇 |
2002年 | 4898篇 |
2001年 | 5305篇 |
2000年 | 4853篇 |
1999年 | 5190篇 |
1998年 | 15440篇 |
1997年 | 10138篇 |
1996年 | 7715篇 |
1995年 | 5746篇 |
1994年 | 4979篇 |
1993年 | 4984篇 |
1992年 | 3347篇 |
1991年 | 3228篇 |
1990年 | 3197篇 |
1989年 | 2997篇 |
1988年 | 2755篇 |
1987年 | 2202篇 |
1986年 | 2270篇 |
1985年 | 2591篇 |
1984年 | 2297篇 |
1983年 | 2046篇 |
1982年 | 1885篇 |
1981年 | 2023篇 |
1980年 | 1778篇 |
1979年 | 1643篇 |
1978年 | 1644篇 |
1977年 | 2015篇 |
1976年 | 2692篇 |
1975年 | 1416篇 |
1974年 | 1358篇 |
1973年 | 1305篇 |
1972年 | 1113篇 |
1971年 | 941篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Seplyarskii B. S. Kochetkov R. A. Lisina T. G. Abzalov N. I. 《Combustion, Explosion, and Shock Waves》2021,57(3):334-342
Combustion, Explosion, and Shock Waves - This paper touches upon the effect of a polyvinyl butyral content (0–2.3%) on the combustion of a Ti + C granular... 相似文献
3.
4.
Multicomponent Diamond-Like Semiconductors Based on the InBV–CdS System: Bulk and Surface Properties
Semiconductors - According to developed methods, in the fields of the mutual solubility of initial binary compounds (InP, InSb, and CdS), solid solutions of the InP–CdS and InSb–CdS... 相似文献
5.
Bryantseva T. A. Markov I. A. Ten Yu. A. 《Journal of Communications Technology and Electronics》2021,66(5):613-621
Journal of Communications Technology and Electronics - Changes in the state of the surface layer of semi-insulating (111) GaAs in air under the action of white light are studied using surface... 相似文献
6.
Egorov A. F. Savitskaya T. V. Mikhailova P. G. 《Theoretical Foundations of Chemical Engineering》2021,55(2):225-252
Theoretical Foundations of Chemical Engineering - An analytical review of the state of multiproduct chemical plants has been proposed. A comprehensive analysis is made of works of Russian and... 相似文献
7.
T.V. Vakalova L.P. Devyashina Sh.M. Sharafeev N.P. Sergeev 《Ceramics International》2021,47(11):15282-15292
One of the drawbacks of fusible clays is the narrow sintering interval due to a sharp increase in the amount of iron-silicate melt at a temperature of 1000–1100 °C, which hardens in the form of a glass phase upon cooling. This leads to a relatively low mechanical strength of the calcined samples and causes the danger of melting the granular material surface from such clays during the firing process. To increase the strength of samples of fusible clays, the influence of diabase and granitoid rocks was considered. It was found that the strengthening effect of diabase and granitoid rock additives in an amount of 20–50% in a mixture with fusible clay is due to an increase of total content of the crystalline phase (mullite, cristobalite and residual quartz) from 18–20% in clays without additives to 22–28 % - in mixtures with diabase and to 28–34% - with granitoid additives) at a temperature of 1050–1100 °C. This increase is due to the activation of synthesis processes of secondary mullite and crystallization from alkali-rich feldspar melt of amorphous silica, released from the structure of clay minerals. The established influence of the igneous rocks used made it possible to develop compositions and propose process flow sheet for producing aluminosilicate proppants based on fusible clays. The use of granitoid and diabase rocks in an amount of 20–70% with fusible clays produces lightweight aluminosilicate proppants with bulk density of 1.40–1.46 g/cm3 at temperature range of 1050–1100 °C, which can endure destructive pressures up to 34.5–52 MPa. 相似文献
8.
Dr. Ezgi Ozyerli-Goknar Dr. Sheikh Nizamuddin Prof. Dr. H. T. Marc Timmers 《ChemMedChem》2021,16(9):1391-1402
Targeting protein-protein interactions (PPIs) with small-molecule inhibitors has become a hotbed of modern drug development. In this review, we describe a new class of PPI inhibitors that block menin from binding to MLL proteins. Menin is encoded by the MEN1 tumor suppressor, but acts as an essential cofactor for MLL/KMT2A-rearranged leukemias. The most promising menin-MLL inhibitors belong to the thienopyrimidine class and have recently entered phase I/II clinical trials for treating acute leukemias characterized by MLL/KMT2A translocations or NPM1 mutations. As single agents, thienopyrimidine compounds eradicate leukemia in a xenograft models of primary leukemic cells belonging to the MLL-rearranged or NPM1-mutant subtypes. These compounds are well tolerated with few or no side effects, which is remarkable given the tumor-suppressor function of menin. The menin-MLL inhibitors highlight how leukemia patients could benefit from a targeted epigenetic therapy with novel PPI inhibitors obtained by directed chemical evolution. 相似文献
9.
Bolshova T. A. Chernov A. A. Shmakov A. G. 《Combustion, Explosion, and Shock Waves》2021,57(2):159-170
Combustion, Explosion, and Shock Waves - Methyl methacrylate (MMA) is the main pyrolysis product of the widely used polymer polymethyl methacrylate; therefore, a compact mechanism of MMA... 相似文献
10.
Castro Mateus B. Souza Raphael R. N. Junior Agord M. P. Lima Eduardo R. Manera Leandro T. 《Analog Integrated Circuits and Signal Processing》2021,109(3):647-656
Analog Integrated Circuits and Signal Processing - This paper presents the complete design of a phase locked loop-based clock synthesizer for reconfigurable analog-to-digital converters. The... 相似文献