全文获取类型
收费全文 | 167629篇 |
免费 | 14435篇 |
国内免费 | 8154篇 |
专业分类
电工技术 | 9694篇 |
技术理论 | 6篇 |
综合类 | 13025篇 |
化学工业 | 27169篇 |
金属工艺 | 9890篇 |
机械仪表 | 11270篇 |
建筑科学 | 12864篇 |
矿业工程 | 4991篇 |
能源动力 | 4744篇 |
轻工业 | 12475篇 |
水利工程 | 3083篇 |
石油天然气 | 9968篇 |
武器工业 | 1335篇 |
无线电 | 18923篇 |
一般工业技术 | 18757篇 |
冶金工业 | 7816篇 |
原子能技术 | 1958篇 |
自动化技术 | 22250篇 |
出版年
2024年 | 655篇 |
2023年 | 2481篇 |
2022年 | 4488篇 |
2021年 | 6201篇 |
2020年 | 4872篇 |
2019年 | 4065篇 |
2018年 | 4392篇 |
2017年 | 4995篇 |
2016年 | 4732篇 |
2015年 | 6486篇 |
2014年 | 8148篇 |
2013年 | 9777篇 |
2012年 | 10963篇 |
2011年 | 11756篇 |
2010年 | 10555篇 |
2009年 | 10227篇 |
2008年 | 10073篇 |
2007年 | 9606篇 |
2006年 | 9838篇 |
2005年 | 8429篇 |
2004年 | 6076篇 |
2003年 | 5597篇 |
2002年 | 5980篇 |
2001年 | 5300篇 |
2000年 | 4294篇 |
1999年 | 4034篇 |
1998年 | 2984篇 |
1997年 | 2491篇 |
1996年 | 2377篇 |
1995年 | 1996篇 |
1994年 | 1582篇 |
1993年 | 1059篇 |
1992年 | 902篇 |
1991年 | 637篇 |
1990年 | 514篇 |
1989年 | 403篇 |
1988年 | 329篇 |
1987年 | 224篇 |
1986年 | 153篇 |
1985年 | 122篇 |
1984年 | 92篇 |
1983年 | 74篇 |
1982年 | 59篇 |
1981年 | 47篇 |
1980年 | 43篇 |
1979年 | 30篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 15篇 |
1959年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Zhao Jiandong Lei Wei Li Zijian Zhao Dongfeng Han Mingmin Hou Xiaoqing 《Multimedia Tools and Applications》2022,81(4):4753-4780
Multimedia Tools and Applications - The crowding in bus is an important factor affecting passenger satisfaction and bus dispatching level. However, how to use video images to detect crowding... 相似文献
2.
Wireless Networks - Geolocation is important for many emerging applications such as disaster management and recommendation system. In this paper, we propose a multilayer recognition model (MRM) to... 相似文献
3.
Sinan Zhang Yadonga Zhao Xueshuang Yao Zhenhong Zheng Chuyao Zheng Zhuo Jiang 《International Journal of Food Science & Technology》2022,57(7):4245-4253
Ripe carambolas are hard to store and transport, while freeze-dried ones are easy to store. However, its long production time leads to higher costs. This study shows that high hydrostatic pressure (HHP) treatment could shorten the freeze-drying time of carambola slices. After HHP treatment (25–250 MPa), the drying time of the fresh sample can be shortened by 33.3–44.4% and the distribution of water and pigment in tissues is much uniform. With the increment of the pressure, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical scavenging rate are increased. At 250 MPa, the total phenolic content (TPC) increased from 11.34 to 13.36 mg GAE g−1, and the total flavonoid content (TFC) of the control sample was increased from 10.77 to 12.73 mg RE g−1. Compared with the untreated sample, HHP treatment can enhance the flavour and shorten the freeze-drying time. This work guides the application of HHP technology for drying food processing. 相似文献
4.
Peiying Wang Juanli Zhao Yun Fan Wei Zhang Yuanyuan Cui Liangmiao Zhang Bin Liu Hongqiang Nian Yiran Li 《Ceramics International》2021,47(11):15023-15029
In this work, the composition-dependent point defect types and formation energies of RE2Hf2O7 (RE = La, Ce, Pr, Nd, Pm, Sm, Eu and Gd) as well as the oxygen diffusion behavior are systematically investigated by first-principles calculations. The possible defect reactions and dominant defect complexes under stoichiometric and non-stoichiometric conditions are revealed. It is found that O Frenkel pairs are the predominant defect in stoichiometric pyrochlore hafnates. Hf-RE cation anti-site defects, accompanied by RE vacancies and/or oxygen interstitials, are stable in the non-stoichiometric case of HfO2 excess. On the other hand, RE-Hf anti-site defects together with oxygen vacancies and/or RE interstitials are preferable in the case of RE2O3 excess. The energy barriers for the migration along the VO48f - VO48f pathway of pyrochlore hafnates were calculated to be between 0.81 eV and 0.89 eV. Based on these results, a defect engineering strategy is proposed and the pyrochlore hafnates investigated here are predicted to exhibit potential oxygen ionic conductivity. 相似文献
5.
Fan Deng-Ping Huang Ziling Zheng Peng Liu Hong Qin Xuebin Van Gool Luc 《国际自动化与计算杂志》2022,19(4):257-287
Machine Intelligence Research - This paper aims to conduct a comprehensive study on facial-sketch synthesis (FSS). However, due to the high cost of obtaining hand-drawn sketch datasets, there is a... 相似文献
6.
Applied Composite Materials - In this paper, the low-velocity impact deformation behavior of biaxial warp-knitted flexible composite was investigated. A simplified finite element model (FEM) of the... 相似文献
7.
8.
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
9.
International Journal of Information Security - Machine learning techniques have been widely used and shown remarkable performance in various fields. Along with the widespread utilization of... 相似文献
10.
Zhang Nan Zhao Man Liu Guangfa Wang Jiaoyang Chen Yunzhi Zhang Zhengjian 《Journal of Materials Science》2022,57(19):8687-8700
Journal of Materials Science - A green modification method for effectively enhancing toughness of PLA was established. Herein, alkaline lignin (LG) was firstly alkylated with dodecane, and then... 相似文献