全文获取类型
收费全文 | 8038篇 |
免费 | 812篇 |
国内免费 | 17篇 |
专业分类
电工技术 | 112篇 |
综合类 | 14篇 |
化学工业 | 1875篇 |
金属工艺 | 381篇 |
机械仪表 | 544篇 |
建筑科学 | 90篇 |
能源动力 | 338篇 |
轻工业 | 670篇 |
水利工程 | 25篇 |
石油天然气 | 5篇 |
无线电 | 1595篇 |
一般工业技术 | 1883篇 |
冶金工业 | 358篇 |
原子能技术 | 144篇 |
自动化技术 | 833篇 |
出版年
2024年 | 8篇 |
2023年 | 100篇 |
2022年 | 154篇 |
2021年 | 234篇 |
2020年 | 193篇 |
2019年 | 242篇 |
2018年 | 307篇 |
2017年 | 308篇 |
2016年 | 357篇 |
2015年 | 310篇 |
2014年 | 452篇 |
2013年 | 557篇 |
2012年 | 560篇 |
2011年 | 682篇 |
2010年 | 448篇 |
2009年 | 500篇 |
2008年 | 455篇 |
2007年 | 367篇 |
2006年 | 349篇 |
2005年 | 271篇 |
2004年 | 246篇 |
2003年 | 265篇 |
2002年 | 215篇 |
2001年 | 190篇 |
2000年 | 137篇 |
1999年 | 160篇 |
1998年 | 194篇 |
1997年 | 98篇 |
1996年 | 91篇 |
1995年 | 62篇 |
1994年 | 66篇 |
1993年 | 57篇 |
1992年 | 31篇 |
1991年 | 22篇 |
1990年 | 25篇 |
1989年 | 20篇 |
1988年 | 16篇 |
1987年 | 22篇 |
1986年 | 16篇 |
1985年 | 13篇 |
1984年 | 17篇 |
1983年 | 13篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 5篇 |
1973年 | 3篇 |
排序方式: 共有8867条查询结果,搜索用时 31 毫秒
1.
Shin Hansub Sim Sungyong Kwon Hyukyoon Hwang Sangheum Lee Younho 《International Journal of Information Security》2022,21(1):25-36
International Journal of Information Security - This paper deals with a well-known problem in the area of the smudge attacks: when a user draws a pattern to unlock the pattern lock on a smartphone... 相似文献
2.
Hong Sae Jin Park Nam Il Hwang Dae Keun Yi Tae Gyu Eum Hyang Lan 《Food science and biotechnology》2022,31(6):669-679
Food Science and Biotechnology - Various hilling materials (rice hulls, pine sawdust, and perlite) were compared to produce sprout vegetables using beach silvertop (Glehnia littoralis Fr. Schm. ex... 相似文献
3.
4.
5.
6.
Machine Learning - We consider the problem of learning a binary classifier from only positive and unlabeled observations (called PU learning). Recent studies in PU learning have shown superior... 相似文献
7.
8.
Muhammad Sheeraz Mamoon Ur Rashid Asad Ali Fazli Akram Ho Jeong Lee Jin San Choi Jong-Seong Bae Yong Soo Kim Young-Han Shin Chang Won Ahn Tae Heon Kim 《Journal of the European Ceramic Society》2021,41(10):5155-5162
We demonstrate the structural evolution of polymorphic phases in Al2O3-inserted SrMnO3 ceramics synthesized by solid state reaction. While the 4H-hexagonal phase is predominant in pure SrMnO3 ceramics, a small amount of 6H-hexagonal polymorph is identified in addition to the primary 4H-hexagonal SrMnO3 and the secondary hexagonal SrAl2O4 phases in the as-sintered ceramics, evidenced by x-ray diffraction and subsequent Rietveld refinement analyses. The existence of the 6H-hexagonal SrMnO3 phase is corroborated using Raman spectroscopy. The chemical compositions and electronic structures of the Al2O3-inserted SrMnO3 compounds are also examined using energy dispersive spectroscopy and x-ray photoelectron spectroscopy, respectively. The first-principles calculations reveal that there is no clear difference between the total energies of 4H- and 6H-hexagonal polymorphs regardless of the presence/absence of Sr and oxygen vacancies. Possible origins are discussed with the estimation of actual strain based on the refined lattice parameter of 6H SrMnO3. 相似文献
9.
10.
A device able to electrokinetically concentrate cationic samples has many potential medical and industrial applications, but until now has remained undeveloped due to the lack of a commercial anion-permselective material leading to a prohibitively complex fabrication procedure. Herein, a novel multiscale-porous anion exchange membrane (MP-AEM) that enables the convenient and scalable electrokinetic concentration of cationic species is proposed. A mechanically enhanced multiscale-porous structure with a solid framework is realized by adopting polyester resin as an additive to overcome the intrinsic limitations of the AEM material. The scalable MP-AEM-embedded electrokinetic concentrator is devised based on the peculiar properties of the MP-AEM that for allow both ion and fluid transport. With the MP-AEM, the concentrator is fabricated in a highly streamlined manner consisting only of a simple insertion and assembly. The concentration performance of the MP-AEM-embedded electrokinetic concentrator is demonstrated with a positively charged fluorescent dye and a fluorescein-labeled protein, and the results show enrichment factors of 250 and 500, respectively. The MP-AEM makes cationic electrokinetic concentration more accessible and scalable, thereby enabling further progress in a wide range of fields. 相似文献