全文获取类型
收费全文 | 259669篇 |
免费 | 3594篇 |
国内免费 | 822篇 |
专业分类
电工技术 | 5130篇 |
综合类 | 330篇 |
化学工业 | 37222篇 |
金属工艺 | 10254篇 |
机械仪表 | 8485篇 |
建筑科学 | 6101篇 |
矿业工程 | 1076篇 |
能源动力 | 6389篇 |
轻工业 | 22852篇 |
水利工程 | 2561篇 |
石油天然气 | 3908篇 |
武器工业 | 68篇 |
无线电 | 34727篇 |
一般工业技术 | 50064篇 |
冶金工业 | 46528篇 |
原子能技术 | 5418篇 |
自动化技术 | 22972篇 |
出版年
2021年 | 2036篇 |
2019年 | 2033篇 |
2018年 | 3467篇 |
2017年 | 3532篇 |
2016年 | 3728篇 |
2015年 | 2319篇 |
2014年 | 4047篇 |
2013年 | 11283篇 |
2012年 | 6561篇 |
2011年 | 8874篇 |
2010年 | 6981篇 |
2009年 | 7848篇 |
2008年 | 8676篇 |
2007年 | 8614篇 |
2006年 | 7802篇 |
2005年 | 7139篇 |
2004年 | 6887篇 |
2003年 | 6731篇 |
2002年 | 6370篇 |
2001年 | 6469篇 |
2000年 | 6169篇 |
1999年 | 6252篇 |
1998年 | 14240篇 |
1997年 | 10268篇 |
1996年 | 8110篇 |
1995年 | 6411篇 |
1994年 | 5714篇 |
1993年 | 5584篇 |
1992年 | 4551篇 |
1991年 | 4213篇 |
1990年 | 4049篇 |
1989年 | 3782篇 |
1988年 | 3624篇 |
1987年 | 3171篇 |
1986年 | 3065篇 |
1985年 | 3610篇 |
1984年 | 3382篇 |
1983年 | 3031篇 |
1982年 | 2850篇 |
1981年 | 2951篇 |
1980年 | 2760篇 |
1979年 | 2648篇 |
1978年 | 2499篇 |
1977年 | 2945篇 |
1976年 | 3554篇 |
1975年 | 2316篇 |
1974年 | 2312篇 |
1973年 | 2318篇 |
1972年 | 1849篇 |
1971年 | 1745篇 |
排序方式: 共有10000条查询结果,搜索用时 19 毫秒
31.
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
32.
María D Torres Herminia Domínguez 《International Journal of Food Science & Technology》2020,55(6):2296-2304
Potato processing industry has a high degree of discarding, which currently has low added value being used primarily for animal feed. However, potato wastes offer a broad range of interesting components such as antioxidants, starch, protein or fibre with potential applications in the food and non-food industries. The recovery of these high valuable fractions using efficient multistage and multiproduct processes could be of great interest. This short review provides a general overview on the integral valorisation of potato wastes, offering an updated vision of the main residual parts generated during potato harvesting and processing, the high valuable obtained components focusing on the bioactive ones and the potential of the emerging extraction techniques over conventional ones. In addition, innovative applications are discussed to highlight the scientific and applied interest of these underutilised and undervalued fractions and to emphasise the integral valorisation of raw materials. 相似文献
33.
Kobrakov K. I. Kurnetsov D. N. Ruchkina A. G. Sharpar N. M. 《Theoretical Foundations of Chemical Engineering》2020,54(5):1052-1056
Theoretical Foundations of Chemical Engineering - New research results, as well as those published earlier by the authors, on the synthesis of azo compounds based on nitroanilines obtained by the... 相似文献
34.
A method is proposed to generate categorical colour observer functions (individual colour matching functions) for any field size based on the CIE 2006 system of physiological observer functions. The method combines proposed categorical observer techniques of Sarkar et al with a physiologically-based individual observer model of Asano et al and a clustering technique to produce the optimal set of categorical observers. The number of required categorical observers varies depending on an application with as many as 50 required to predict individual observers' matches when a laser projector is viewed. However, 10 categorical observers are sufficient to represent colour-normal populations for personalized colour imaging. The proposed and recommended categorical observers represent a robust and inclusive technique to examine and quantify observer metamerism in any application of colorimetry. 相似文献
35.
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
36.
37.
Pasquale Stano Tereza Pereira de Souza Paolo Carrara Emiliano Altamura Erica D’Aguanno Margherita Caputo 《先进材料力学与结构力学》2015,22(9):748-759
Here we report some recent biophysical issues on the preparation of solute-filled lipid vesicles and their relevance to the construction of “synthetic cells.” First, we introduce the “semi-synthetic minimal cells” as the liposome-based cell-like systems, which contain a minimal number of biomolecules required to display simple and complex biological functions. Next, we focus on recent aspects related to the construction of synthetic cells. Emphasis is given to the interplay between the methods of synthetic cell preparation and the physics of solute encapsulation. We briefly introduce the notion of structural and compositional “diversity” in synthetic cell populations. 相似文献
38.
Effect of gums on viability and β‐galactosidase activity of Lactobacillus spp. in milk drink during refrigerated storage 下载免费PDF全文
Bernice D. Karlton‐Senaye Reza Tahergorabi Valerie L. Giddings Salam A. Ibrahim 《International Journal of Food Science & Technology》2015,50(1):32-40
The viability and β‐galactosidase activity of four Lactobacillus strains in milk drink containing gums during 28 days of refrigerated storage at 4 °C were assessed. The population of Lactobacillus rhamnosus GGB101 and Lactobacillus rhamnosus GGB103 were maintained, whereas the population of Lactobacillus reuteri DSM20016 and Lactobacillus reuteri SD2112 significantly decreased. The recommended level of 6 log CFU g?1 was exceeded for all tested trains throughout storage. The highest viable number of Lactobacillus rhamnosus GGB103 (8.76 ± 0.03 log CFU mL?1) was obtained in the product containing carrageenan–maltodextrin. The addition of guar–locust bean–carrageenan led to 20‐fold increase in the level of β‐galactosidase activity for L. rhamnosus GGB101 (1208 ± 2.12 Miller units mL?1) compared to the control (61 ± 2.83 Miller units mL?1). Our results suggested that gums could be added to milk to improve viability and enhance β‐galactosidase activity of Lactobacillus. 相似文献
39.
40.