全文获取类型
收费全文 | 99778篇 |
免费 | 8474篇 |
国内免费 | 4286篇 |
专业分类
电工技术 | 5665篇 |
技术理论 | 6篇 |
综合类 | 6291篇 |
化学工业 | 16629篇 |
金属工艺 | 6174篇 |
机械仪表 | 7084篇 |
建筑科学 | 8123篇 |
矿业工程 | 3414篇 |
能源动力 | 2935篇 |
轻工业 | 6321篇 |
水利工程 | 1669篇 |
石油天然气 | 7358篇 |
武器工业 | 805篇 |
无线电 | 10775篇 |
一般工业技术 | 11618篇 |
冶金工业 | 4917篇 |
原子能技术 | 1026篇 |
自动化技术 | 11728篇 |
出版年
2024年 | 456篇 |
2023年 | 1793篇 |
2022年 | 3152篇 |
2021年 | 4272篇 |
2020年 | 3342篇 |
2019年 | 2716篇 |
2018年 | 2927篇 |
2017年 | 3303篇 |
2016年 | 3062篇 |
2015年 | 4135篇 |
2014年 | 4926篇 |
2013年 | 5869篇 |
2012年 | 6340篇 |
2011年 | 6760篇 |
2010年 | 5816篇 |
2009年 | 5535篇 |
2008年 | 5390篇 |
2007年 | 5110篇 |
2006年 | 5447篇 |
2005年 | 4736篇 |
2004年 | 3005篇 |
2003年 | 2855篇 |
2002年 | 2676篇 |
2001年 | 2434篇 |
2000年 | 2351篇 |
1999年 | 2672篇 |
1998年 | 2110篇 |
1997年 | 1743篇 |
1996年 | 1725篇 |
1995年 | 1427篇 |
1994年 | 1167篇 |
1993年 | 744篇 |
1992年 | 655篇 |
1991年 | 444篇 |
1990年 | 351篇 |
1989年 | 304篇 |
1988年 | 228篇 |
1987年 | 151篇 |
1986年 | 122篇 |
1985年 | 72篇 |
1984年 | 54篇 |
1983年 | 46篇 |
1982年 | 41篇 |
1981年 | 28篇 |
1980年 | 25篇 |
1979年 | 16篇 |
1978年 | 1篇 |
1965年 | 1篇 |
1959年 | 2篇 |
1951年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
34.
35.
Anxiang Su Gaoxing Ma Minhao Xie Yang Ji Xiangfei Li Liyan Zhao Qiuhui Hu 《International Journal of Food Science & Technology》2019,54(6):2277-2287
In this study, in vitro digestion and fermentation of Flammulina velutipes -derived polysaccharides (FVP) were investigated. It was found that FVP mainly consisted of 48.45% glucose, 15.40% mannose, 14.60% xylose, 11.80% fucose and 9.90% galactose. The -human saliva, simulated gastric and small intestinal juices conditions did not break down the FVP. Based on in vitro fermentation tests, FVP modulated the composition of gut microbiota by elevating the amounts of Bifidobacteriaceae and Bacteroidaceae and reducing the numbers of genera Lachnospiraceae and Enterococcaceae. Meanwhile, FVP affected the synthesis of short-chain fatty acids derived from gut microbiota. 相似文献
36.
Chaoxin Li Yi Zhou Yuming Tian Yuanyuan Zhao Kaiyue Wang Guomin Li Yuesheng Chai 《Ceramics International》2019,45(5):5613-5616
Ceramics with mullite whiskers were prepared from coal fly ash and Al2O3 raw materials, with AlF3 used as an additive. The phase structures and microstructures of the ceramics were identified via X-ray diffraction and scanning electron microscopy, respectively. The results show that pickling of coal fly ash is an effective method for enhancing the flexural strength of ceramics. Sintering temperature and AlF3 addition were also key factors influencing the creation of ideal ceramics. The ceramic made from pickled coal fly ash, 6?wt% AlF3, and sintered at 1200?°C, exhibited the highest flexural strength of 59.1?MPa, and had a bulk density of 1.32?g/cm3 and porosity of 26.8%. The results show that ceramic materials made under these conditions are ideal candidates for manufacturing ceramic proppants for the exploitation of unconventional oil and gas resources. 相似文献
37.
38.
39.
E-voting maybe replaces the traditional voting scheme in the future, however, the security threat must be paid enough attention. In this paper, a novel e-voting scheme is proposed using secret sharing and k-anonymity, which not only satisfies the basic security goals such as the non-cheating, the universal verifiability, the confidentiality, and the anonymity, but also achieves the addition properties including coercion-resistance and unconditional security since the security of the proposed scheme does not rely on any computational hard problem.
相似文献40.
Zhang Xi Wang Xianhai Zhao Hongke Ordóñez de Pablos Patricia Sun Yongqiang Xiong Hui 《Scientometrics》2019,119(3):1311-1344
Scientometrics - Altmetrics indices are increasingly applied to measure scholarly influence in recent years because they can reflect the influence of research outputs more timely comparing with... 相似文献