全文获取类型
收费全文 | 10370篇 |
免费 | 49篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 140篇 |
化学工业 | 513篇 |
金属工艺 | 309篇 |
机械仪表 | 75篇 |
建筑科学 | 61篇 |
矿业工程 | 2篇 |
能源动力 | 120篇 |
轻工业 | 117篇 |
水利工程 | 19篇 |
石油天然气 | 9篇 |
无线电 | 442篇 |
一般工业技术 | 407篇 |
冶金工业 | 119篇 |
原子能技术 | 104篇 |
自动化技术 | 7989篇 |
出版年
2023年 | 13篇 |
2022年 | 31篇 |
2021年 | 47篇 |
2020年 | 31篇 |
2019年 | 35篇 |
2018年 | 60篇 |
2017年 | 46篇 |
2016年 | 54篇 |
2015年 | 36篇 |
2014年 | 250篇 |
2013年 | 276篇 |
2012年 | 820篇 |
2011年 | 2343篇 |
2010年 | 1160篇 |
2009年 | 1015篇 |
2008年 | 727篇 |
2007年 | 628篇 |
2006年 | 469篇 |
2005年 | 588篇 |
2004年 | 529篇 |
2003年 | 594篇 |
2002年 | 294篇 |
2001年 | 19篇 |
2000年 | 12篇 |
1999年 | 16篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 14篇 |
1995年 | 10篇 |
1994年 | 14篇 |
1993年 | 11篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 11篇 |
1988年 | 18篇 |
1987年 | 12篇 |
1986年 | 13篇 |
1985年 | 16篇 |
1984年 | 16篇 |
1983年 | 20篇 |
1982年 | 15篇 |
1981年 | 22篇 |
1980年 | 15篇 |
1979年 | 9篇 |
1978年 | 13篇 |
1977年 | 8篇 |
1976年 | 11篇 |
1975年 | 13篇 |
1974年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
This paper presents a gravity optimised particle filter (GOPF) where the magnitude of the gravitational force for every particle is proportional to its weight. GOPF attracts nearby particles and replicates new particles as if moving the particles towards the peak of the likelihood distribution, improving the sampling efficiency. GOPF is incorporated into a technique for hand features tracking. A fast approach to hand features detection and labelling using convexity defects is also presented. Experimental results show that GOPF outperforms the standard particle filter and its variants, as well as state-of-the-art CamShift guided particle filter using a significantly reduced number of particles. 相似文献
72.
Ran Zheng Qiongyao ZhangAuthor Vitae Hai JinZhiyuan ShaoAuthor Vitae Xiaowen FengAuthor Vitae 《Computers & Electrical Engineering》2014
Evolutionary trees are widely applied in various applications to show the inferred evolutionary relationships among species or entities. Neighbor-Joining is one solution for data-intensive and time-consuming evolutionary tree construction, with polynomial time complexity. However, its performance becomes poorer with the growth of massive datasets. Graphics Processing Units (GPUs) have brought about new opportunities for these time-consuming applications. Based on its high efficiency, a GPU-based parallel Neighbor-Joining method is proposed, and two efficient parallel mechanisms, data segmentation with asynchronous processing and the minimal chain model with bitonic sort, are put forward to speed up the processing. The experimental results show that an average speedup of 25.1 is achieved and even approximately 30 can be obtained with a sequence dataset ranging from 16,000 to 25,000. Moreover, the proposed parallel mechanisms can be effectively exploited in some other high performance applications. 相似文献
73.
Xin Xu Xiaolong ZhangAuthor VitaeHaidong FuAuthor Vitae Li ChenAuthor VitaeHong ZhangAuthor Vitae Xiaowei FuAuthor Vitae 《Computers & Electrical Engineering》2014
A robust autofocus system is a ubiquitous function in today’s mobile phone camera applications. However, due to the power consumption and size requirements, it is difficult for the autofocus function to be implemented into the design of mobile phone cameras. This paper presents a passive autofocus system with low computational complexity. This system uses a novel contrast measurement to determine degree of image sharpness, which can better reflect the information about image discontinuities. In order to gauge the performance of this measurement, a modified peak search strategy is used in the experiments. The experimental results from several typical image sequences validate the effectiveness of the proposed method. 相似文献
74.
Dayang SunAuthor Vitae Hongrun ZhangAuthor VitaeZhihong Qian 《Computers & Electrical Engineering》2014
Non-Line-of-Sight propagation of wireless signal has an impact on measured distances in range-based localization and will bias the final localization results. A new localization algorithm is proposed in this paper to mitigate Non-Line-of-Sight errors when there are more than enough anchor nodes deployed around the node to be located. This algorithm utilizes multi-round clustering analysis to filter the pre-located estimators which derive from all possible subsets of measured distances. In each round, the method density-based spatial clustering of applications with noise is adopted. Simulations show that the proposed algorithm can effectively improve localization accuracy not only when the measured distances with Non-Line-of-Sight error are minor but also under the condition that all of them suffer random Non-Line-of-Sight error. 相似文献
75.
In tiled Chip Multiprocessors (CMPs) last-level cache (LLC) banks are usually shared but distributed among the tiles. A static mapping of cache blocks to the LLC banks leads to poor efficiency since a block may be mapped away from the tiles actually accessing it. Dynamic policies either rely on the static mapping of blocks to a set of banks (D-NUCA) or rely on the OS to dynamically load pages to statically mapped addresses (first-touch). 相似文献
76.
The HUB-CI model is investigated in a telerobotic system in a client/server network to manage the lifecycle of engineering design and prototyping. The purpose of this platform is to support collaborative engineering design and proof of concept to enhance distributed team collaboration and resource utilization. The suggested platform is exemplified in two collaboration support tools and a physical prototyping platform. Structured Co-Insight Management is developed to support innovative idea exchanges and the consensus decision-making during the design process. Conflict/error detection management helps preventing conflicts and errors during the lifecycle of design and development. Physical collaboration over the network occurs when a team controls the telerobot operation during prototyping and testing in design cycles. A pilot system is implemented with a group project for the design of an electronic circuit (including both hardware and software designs). The functional assessment method is used to compare this platform to other collaborative design tools. The system presented offers unique qualitative advantages as an integrated collaboration support system. 相似文献
77.
78.
79.
Alok Singh Sitaram Dash Mohammed Kamruddin Puthupparampil K. Ajikumar Ashok K. Tyagi Vinjamoor S. Raghunathan Baldev Raj 《Journal of the American Ceramic Society》2002,85(4):927-932
Formation of nanocrystalline calcia from calcite has been studied in situ via transmission electron microscopy. The crystallographic transformation occurred via two mechanisms: the first is by distortion of the cleaved rhombohedron of calcite, formed by {104} planes in hexagonal coordinates, into a cube. This produced a microstructure of oriented, elongated nanocrystals of calcia with planar boundaries. In the second mechanism, the micrometer-sized parent calcite particles broke up into nano-sized grains as the decomposition began, leading to irregularly shaped, randomly oriented nanocrystals of calcia. 相似文献
80.
Novel self-curable cathodically depositable coatings were developed from glycidyl functional epoxy ester-acrylic graft co-polymer (EEAG) without using any external crosslinking agents. The EEAG-amine adducts (EEAGAs) were prepared by reacting EEAG with varying amount of diethanolamine (DEoA) which are neutralized with acid and dispersed in deionised water to give stable dispersion for cathodic electrodeposition (CED) coatings. The dispersions were cathodically electrodeposited on phosphated steel panels and thermally cured to give uniform coating. The coatings were evaluated for different mechanical, chemical and corrosion resistance properties. The coatings were evaluated for their thermal properties using thermo gravimetric analysis (TGA). The final properties of the coatings were found to be affected by the amount of amine reacted with epoxy. The coating films showed good overall performance properties for their use in coating industry. 相似文献