全文获取类型
收费全文 | 37888篇 |
免费 | 2984篇 |
国内免费 | 1489篇 |
专业分类
电工技术 | 1889篇 |
技术理论 | 2篇 |
综合类 | 2244篇 |
化学工业 | 6423篇 |
金属工艺 | 2129篇 |
机械仪表 | 2363篇 |
建筑科学 | 2945篇 |
矿业工程 | 924篇 |
能源动力 | 886篇 |
轻工业 | 2288篇 |
水利工程 | 545篇 |
石油天然气 | 2602篇 |
武器工业 | 202篇 |
无线电 | 4681篇 |
一般工业技术 | 4773篇 |
冶金工业 | 2083篇 |
原子能技术 | 404篇 |
自动化技术 | 4978篇 |
出版年
2024年 | 204篇 |
2023年 | 658篇 |
2022年 | 944篇 |
2021年 | 1412篇 |
2020年 | 1093篇 |
2019年 | 906篇 |
2018年 | 1013篇 |
2017年 | 1186篇 |
2016年 | 1078篇 |
2015年 | 1371篇 |
2014年 | 1741篇 |
2013年 | 2219篇 |
2012年 | 2154篇 |
2011年 | 2457篇 |
2010年 | 2210篇 |
2009年 | 2028篇 |
2008年 | 2024篇 |
2007年 | 2010篇 |
2006年 | 2034篇 |
2005年 | 1766篇 |
2004年 | 1206篇 |
2003年 | 1047篇 |
2002年 | 1016篇 |
2001年 | 867篇 |
2000年 | 899篇 |
1999年 | 1091篇 |
1998年 | 949篇 |
1997年 | 830篇 |
1996年 | 822篇 |
1995年 | 630篇 |
1994年 | 546篇 |
1993年 | 380篇 |
1992年 | 341篇 |
1991年 | 255篇 |
1990年 | 194篇 |
1989年 | 170篇 |
1988年 | 141篇 |
1987年 | 104篇 |
1986年 | 77篇 |
1985年 | 58篇 |
1984年 | 57篇 |
1983年 | 30篇 |
1982年 | 37篇 |
1981年 | 25篇 |
1980年 | 18篇 |
1979年 | 11篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1973年 | 5篇 |
1970年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Sun Yuxiang Yuan Bo Zhang Yongliang Zheng Wanwen Xia Qingfeng Tang Bojian Zhou Xianzhong 《International Journal of Control, Automation and Systems》2021,19(9):2984-2998
International Journal of Control, Automation and Systems - The reinforcement learning problem of complex action control in multiplayer online battlefield games has brought considerable interest in... 相似文献
32.
Tang Jingge Chang Jian Li Bin Zhang Aiqun 《International Journal of Control, Automation and Systems》2021,19(9):3190-3198
International Journal of Control, Automation and Systems - An underwater gliding snake-like robot (UGSR) combines the advantages of an underwater glider (UG) and an underwater snake-like robot... 相似文献
33.
Zhu Fanglai Shan Yu Tang Yuyan 《International Journal of Control, Automation and Systems》2021,19(9):3075-3086
International Journal of Control, Automation and Systems - In this paper, we discuss actuator fault and sensor fault detection and isolation (FDI) problems for a class of switched nonlinear systems... 相似文献
34.
The layer structured zirconium phosphate(Zr P) can be intercalated with atoms, molecules, small organic groups and even polymers. The structures and properties of the Zr P intercalation compounds can be deliberately tuned, leading to promising potential applications in many fields. This article provides a brief review on the experimental results of the Zr P intercalation compounds, with the focus on the polymer/a-zirconium phosphate (α-Zr P) nano-composites. The computer simulations of the Zr P intercalation compounds at the atomic level play a significant role in designing and understanding the properties of Zr P, and in the promotion of the applications of compounds. 相似文献
35.
Commercially available, gas-atomized CoNiCrAlY powder was cryomilled to produce powder with nanocrystalline grains. The cryomilled powder and conventional gas-atomized powder were thermally sprayed using the HVOF process to prepare two coatings with fine-grain (~15 nm) and coarse-grain (~1 μm) microstructure, respectively. The two coatings were isothermally oxidized in air at 1000° C for up to 330 hr. The morphology and composition of the oxide scales formed on the two coatings were compared with each other. The results indicate that, while a fine-grain microstructure can promote the formation of a pure alumina layer on the coating by increasing the Al diffusion rate toward the surface, it can also accelerate the Al depletion by increasing the Al diffusion rate toward the substrate, which results in the formation of non-alumina oxides after long-term oxidation. The mechanisms governing the oxide formation are discussed in terms of atomic diffusion and thermodynamic stability. 相似文献
36.
F. Liu J. E. Tang T. Jonsson S. Canovic K. Segerdahl J. -E. Svensson M. Halvarsson 《Oxidation of Metals》2006,66(5-6):295-319
FIB, SEM and STEM/EDX were used to investigate X20 stainless-steel samples exposed to dry O2, or O2 containing 40% H2O, with a flow velocity of 0.5 cm/s or 5 cm/s, for 168 hr or 336 hr at 600°C. Thin protective Cr-rich (Cr,Fe)2O3 was maintained on the samples exposed to dry O2, even after 336 hr, and on the sample exposed to O2/H2O mixture with the low-flow velocity (0.5 cm/s) for 168 hr. The oxide scale formed in the latter environment contained less Cr, due to Cr loss through CrO2(OH)2 evaporation. Breakaway oxidation occurred on the samples exposed in high-gas-flow velocity for shorter time (168 hr) or in low-gas-flow velocity (0.5 cm/s) for longer time (336 hr). The breakaway scales featured a two-layered structure: an outward-growing oxide “island” consisting of almost pure hematite (α-Fe2O3), and an inward-growing oxide “crater” consisting of (Cr,Fe)3O4. The transition from a thin protective (Cr,Fe)2O3 scale to a non-protective thick scale on this martensitic/ferritic steel originated locally and was followed by rapid oxide growth, resulting in a thick scale that covered the whole sample surface. 相似文献
37.
研究了保温时间和保温温度对电磁搅拌ZL117合金半固态浆料稳定性的影响.试验结果表明:半固态浆料中初生Si的颗粒直径随着保温时间的延长而逐渐增大,但在前15 min内增长速度比较缓慢,15 min后增长较快;随着保温温度的升高而缓慢增大;初生Si的形状系数随着保温时间的延长而变得越来越大,但也在前15 min内变化较为缓慢,15 min后变大速度突然加快;初生Si的形状系数在620 ℃下保温时最小,在610~620 ℃之间随着保温温度的升高而缓慢变小;在620~650 ℃之间随着保温温度的升高而逐渐增加. 相似文献
38.
39.
Sibang Liu Shuzhi Sam Ge Zhongliang Tang 《International Journal of Control, Automation and Systems》2016,14(4):924-938
This paper presents a modular designed autonomous bolt tightening shaft system with an adaptive fuzzy backstepping control approach developed for it. The bolt tightening shaft is designed for the autonomous bolt tightening operation, which has huge potential for industry application. Due to the inherent nonlinear and uncertain properties, the bolt tightening shaft and the bolt tightening process are mathematically modeled as an uncertain strict feedback system. With the adaptive backstepping and approximation property of fuzzy logic system, the controller is recursively designed. Based on the Lyapunov stability theorem, all signals in the closed-loop system are proved to be uniformly ultimately bounded and the torque tracking error exponentially converges to a small residue. And the effectiveness and performance of the proposed autonomous system are verified by the simulation and experiment results on the bolt tightening shaft system. 相似文献
40.
体育是文化的重要组成部分,不管是在世界,还是在国内,都已经成为了人们日常生活的一部分,也影响着人们的生活。中职的体育教学是培养人才的重要手段,蕴含着丰富的教育功能。在中职体育教学中,通过体育礼仪的教育可以提高中职学生的礼仪修养,进而促进学生整体思想水平和境界的提升。 相似文献