全文获取类型
收费全文 | 608647篇 |
免费 | 9960篇 |
国内免费 | 3053篇 |
专业分类
电工技术 | 12458篇 |
综合类 | 1549篇 |
化学工业 | 90058篇 |
金属工艺 | 26042篇 |
机械仪表 | 20322篇 |
建筑科学 | 14586篇 |
矿业工程 | 3149篇 |
能源动力 | 16932篇 |
轻工业 | 48848篇 |
水利工程 | 5857篇 |
石油天然气 | 9879篇 |
武器工业 | 135篇 |
无线电 | 74518篇 |
一般工业技术 | 119216篇 |
冶金工业 | 114947篇 |
原子能技术 | 12151篇 |
自动化技术 | 51013篇 |
出版年
2021年 | 6051篇 |
2020年 | 4556篇 |
2019年 | 5508篇 |
2018年 | 8966篇 |
2017年 | 8877篇 |
2016年 | 9481篇 |
2015年 | 6641篇 |
2014年 | 10464篇 |
2013年 | 29488篇 |
2012年 | 16690篇 |
2011年 | 22352篇 |
2010年 | 17955篇 |
2009年 | 19985篇 |
2008年 | 20585篇 |
2007年 | 20225篇 |
2006年 | 18368篇 |
2005年 | 16630篇 |
2004年 | 15581篇 |
2003年 | 15545篇 |
2002年 | 15004篇 |
2001年 | 14795篇 |
2000年 | 13760篇 |
1999年 | 14682篇 |
1998年 | 36706篇 |
1997年 | 25614篇 |
1996年 | 19929篇 |
1995年 | 14827篇 |
1994年 | 13061篇 |
1993年 | 12937篇 |
1992年 | 9326篇 |
1991年 | 8921篇 |
1990年 | 8583篇 |
1989年 | 8185篇 |
1988年 | 7862篇 |
1987年 | 6883篇 |
1986年 | 6728篇 |
1985年 | 7672篇 |
1984年 | 6983篇 |
1983年 | 6293篇 |
1982年 | 5853篇 |
1981年 | 5847篇 |
1980年 | 5468篇 |
1979年 | 5222篇 |
1978年 | 5176篇 |
1977年 | 6136篇 |
1976年 | 8468篇 |
1975年 | 4449篇 |
1974年 | 4199篇 |
1973年 | 4234篇 |
1972年 | 3579篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
61.
Klimis?S.?NtalianisEmail author Anastasios?D.?Doulamis Nikolaos?D.?Doulamis Nikos?E.?Mastorakis Athanasios?S.?Drigas 《Journal of Signal Processing Systems》2015,80(2):153-161
In this paper, we present a novel memory access reduction scheme (MARS) for two-dimension fast cosine transform (2-D FCT). It targets programmable DSPs with high memory-access latency. It reduces the number of memory accesses by: 1) reducing the number of weighting factors and 2) combining butterflies in vector-radix 2-D FCT pruning diagram from two stages to one stage with an efficient structure. Hardware platform based on general purpose processor is used to verify the effectiveness of the proposed method for vector-radix 2-D FCT pruning implementation. Experimental results validate the benefits of the proposed method with reduced memory access, less clock cycle and fewer memory space compared with the conventional implementation. 相似文献
62.
63.
Material encapsulation is a relatively new technique for coating a micro/nanosize particle or droplet with polymeric or inorganic shell. Encapsulation technology has many applications in various fields including drug delivery, cosmetic, agriculture, thermal energy storage, textile, and self-healing polymers. Poly(methyl methacrylate) (PMMA) is widely used as shell material in encapsulation due to its high chemical stability, biocompatibility, nontoxicity, and good mechanical properties. The main approach for micro/nanoencapsulation of materials using PMMA as shell comprises emulsion-based techniques such as emulsion polymerization and solvent evaporation from oil-in-water emulsion. In the present review, we first focus on the encapsulation techniques of liquid materials with PMMA shell by analyzing the effective processing parameters influencing the preparation of PMMA micro/nanocapsules. We then describe the morphology of PMMA capsules in emulsion systems according to thermodynamic relations. The techniques to investigation of mechanical properties of capsule shell and the release mechanisms of core material from PMMA capsules were also investigated. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48039. 相似文献
64.
65.
66.
Fermanelli Carla S. Galarza Emilce D. Pierella Liliana B. Renzini María S. Saux Clara 《Topics in Catalysis》2019,62(12-16):918-930
Topics in Catalysis - In this work, a simple thermal-catalytic system was used to valorize peanut shells (Arachis hypogaea), the residual biomass from the peanut industry. To accomplish this... 相似文献
67.
Polymer Bulletin - Preparation of konjac glucomannan-grafted poly(trimethyl allyl ammonium chloride) (KGM-g-PTMAAC) was carried out using KGM as polysaccharide matrix and TMAAC as cationic... 相似文献
68.
Gomes A. C. S. A. Costa L. C. Brito D. C. Frana R. J. Marques Mnica R. C. 《Polymer Bulletin》2020,77(4):1969-1981
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
69.
Bankov S. E. Vesnik M. V. Kravchenko V. F. 《Journal of Communications Technology and Electronics》2020,65(4):398-405
Journal of Communications Technology and Electronics - Abstract—The article presents a rigorous numerical solution, using the Wiener–Hopf method, to the problem of plane wave... 相似文献
70.
Wireless Personal Communications - The orthogonal frequency division multiplexing (OFDM) is the most encouraging multi-carrier modulation system chosen for the high data rates but the objective is... 相似文献