全文获取类型
收费全文 | 52535篇 |
免费 | 3083篇 |
国内免费 | 89篇 |
专业分类
电工技术 | 390篇 |
综合类 | 144篇 |
化学工业 | 12692篇 |
金属工艺 | 1027篇 |
机械仪表 | 1046篇 |
建筑科学 | 1682篇 |
矿业工程 | 121篇 |
能源动力 | 1678篇 |
轻工业 | 9818篇 |
水利工程 | 490篇 |
石油天然气 | 306篇 |
武器工业 | 4篇 |
无线电 | 2342篇 |
一般工业技术 | 7741篇 |
冶金工业 | 8750篇 |
原子能技术 | 328篇 |
自动化技术 | 7148篇 |
出版年
2024年 | 96篇 |
2023年 | 463篇 |
2022年 | 1240篇 |
2021年 | 1772篇 |
2020年 | 1161篇 |
2019年 | 1310篇 |
2018年 | 1776篇 |
2017年 | 1800篇 |
2016年 | 1918篇 |
2015年 | 1454篇 |
2014年 | 1981篇 |
2013年 | 3880篇 |
2012年 | 3172篇 |
2011年 | 3491篇 |
2010年 | 2665篇 |
2009年 | 2571篇 |
2008年 | 2340篇 |
2007年 | 2019篇 |
2006年 | 1648篇 |
2005年 | 1392篇 |
2004年 | 1273篇 |
2003年 | 1205篇 |
2002年 | 1022篇 |
2001年 | 790篇 |
2000年 | 715篇 |
1999年 | 786篇 |
1998年 | 3089篇 |
1997年 | 2014篇 |
1996年 | 1384篇 |
1995年 | 771篇 |
1994年 | 664篇 |
1993年 | 624篇 |
1992年 | 245篇 |
1991年 | 221篇 |
1990年 | 169篇 |
1989年 | 199篇 |
1988年 | 194篇 |
1987年 | 176篇 |
1986年 | 139篇 |
1985年 | 181篇 |
1984年 | 133篇 |
1983年 | 103篇 |
1982年 | 105篇 |
1981年 | 118篇 |
1980年 | 130篇 |
1979年 | 65篇 |
1978年 | 64篇 |
1977年 | 203篇 |
1976年 | 398篇 |
1973年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
Mri Miczi Mria Golda Balzs Kunkli Tibor Nagy Jzsef Tzsr Jnos Andrs Mtyn 《International journal of molecular sciences》2020,21(24)
The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease-19 (COVID-19) being associated with severe pneumonia. Like with other viruses, the interaction of SARS-CoV-2 with host cell proteins is necessary for successful replication, and cleavage of cellular targets by the viral protease also may contribute to the pathogenesis, but knowledge about the human proteins that are processed by the main protease (3CLpro) of SARS-CoV-2 is still limited. We tested the prediction potentials of two different in silico methods for the identification of SARS-CoV-2 3CLpro cleavage sites in human proteins. Short stretches of homologous host-pathogen protein sequences (SSHHPS) that are present in SARS-CoV-2 polyprotein and human proteins were identified using BLAST analysis, and the NetCorona 1.0 webserver was used to successfully predict cleavage sites, although this method was primarily developed for SARS-CoV. Human C-terminal-binding protein 1 (CTBP1) was found to be cleaved in vitro by SARS-CoV-2 3CLpro, the existence of the cleavage site was proved experimentally by using a His6-MBP-mEYFP recombinant substrate containing the predicted target sequence. Our results highlight both potentials and limitations of the tested algorithms. The identification of candidate host substrates of 3CLpro may help better develop an understanding of the molecular mechanisms behind the replication and pathogenesis of SARS-CoV-2. 相似文献
63.
64.
65.
66.
67.
María Clara Verdi Constanza Melian Patricia Castellano Graciela Vignolo Mariana Blanco Massani 《International Journal of Food Science & Technology》2020,55(1):267-275
The effectiveness of antimicrobial mixtures against Listeria innocua 7, used as a L. monocytogenes surrogate, was investigated in broth and a food system. Synergistic effects were found for nisin (Nis), potassium sorbate (PS), calcium propionate (CP) and sodium lactate (SL), Nis + PS being the most effective binary mixture that exhibited listericidal activity in broth. To assess the effect of adding lactocin AL705 (AL705) to Nis + organic acid salt combinations, tridimensional isobolograms were generated. Sub-MIC combinations of the antimicrobials exerted bactericidal activity against L. innocua 7 after AL705 addition to the binary mixtures. However, when applied on Sardo cheese contaminated with L. innocua 7 (initial inoculum 4.45 ± 0.06 CFU g−1), only Nis + PS + AL705 produced count reductions respect to the control, reaching 3.04 ± 0.35 CFU g−1 counts after 15 days at 15 °C. Ternary combinations containing AL705 showed potential to reduce antimicrobial usages for L. innocua 7 inhibition. 相似文献
68.
Hierarchical micro-nanostructured albite-based glass-ceramic for high dielectric strength insulators
V. Fuertes M.J. Cabrera J. Seores D. Muñoz J.F. Fernández E. Enríquez 《Journal of the European Ceramic Society》2018,38(7):2759-2766
A novel glass-ceramic material based on albite type Na-rich feldspar has been synthesized by conventional ceramic process. High crystallinity, >94%?Vol.% is obtained by fast sintering which allows energy saving processing. Albite is the main crystalline phase and tetragonal SiO2 is a secondary phase. Electrical properties were examined by complex impedance, DC measurements, and dielectric breakdown test. Dielectric characterization shows a non-Debye type dielectric behavior with low dielectric constant, 4.6 at 1?MHz, low dielectric losses, (~10?3 at 1?MHz, and a large dielectric strength, ~60?kV/mm), that it is the largest value reported in ceramic insulators. Those dielectric properties are attained by the low glassy phase content in the samples and their unique micro-nanostructure. All these properties make this novel material a very promising candidate in the market of ceramic electrical insulator, highlighting for high-voltage applications. 相似文献
69.