全文获取类型
收费全文 | 1811篇 |
免费 | 53篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 21篇 |
化学工业 | 315篇 |
金属工艺 | 45篇 |
机械仪表 | 91篇 |
建筑科学 | 51篇 |
矿业工程 | 4篇 |
能源动力 | 65篇 |
轻工业 | 72篇 |
水利工程 | 6篇 |
石油天然气 | 9篇 |
无线电 | 228篇 |
一般工业技术 | 415篇 |
冶金工业 | 237篇 |
原子能技术 | 68篇 |
自动化技术 | 247篇 |
出版年
2023年 | 22篇 |
2022年 | 41篇 |
2021年 | 44篇 |
2020年 | 42篇 |
2019年 | 39篇 |
2018年 | 37篇 |
2017年 | 34篇 |
2016年 | 41篇 |
2015年 | 33篇 |
2014年 | 57篇 |
2013年 | 118篇 |
2012年 | 66篇 |
2011年 | 102篇 |
2010年 | 90篇 |
2009年 | 75篇 |
2008年 | 79篇 |
2007年 | 69篇 |
2006年 | 60篇 |
2005年 | 35篇 |
2004年 | 37篇 |
2003年 | 43篇 |
2002年 | 36篇 |
2001年 | 28篇 |
2000年 | 28篇 |
1999年 | 22篇 |
1998年 | 39篇 |
1997年 | 36篇 |
1996年 | 33篇 |
1995年 | 32篇 |
1994年 | 29篇 |
1993年 | 25篇 |
1992年 | 20篇 |
1991年 | 29篇 |
1990年 | 31篇 |
1989年 | 19篇 |
1988年 | 22篇 |
1987年 | 21篇 |
1986年 | 16篇 |
1985年 | 18篇 |
1984年 | 26篇 |
1983年 | 20篇 |
1982年 | 25篇 |
1981年 | 21篇 |
1980年 | 14篇 |
1979年 | 17篇 |
1978年 | 11篇 |
1977年 | 19篇 |
1976年 | 30篇 |
1975年 | 6篇 |
1973年 | 9篇 |
排序方式: 共有1874条查询结果,搜索用时 15 毫秒
11.
Sinha Swati Shaw Siddharth Biswas Kunal De Debashis Das Samir Chandra Sarkar Angsuman Bandyopadhyay Jaya 《Microsystem Technologies》2021,27(11):4087-4100
Microsystem Technologies - Single-Walled Carbon Nanotubes (SWCNTs) are widely used as potential carriers in drug delivery systems. The objective of this work was to observe the effects of pristine,... 相似文献
12.
Desulphurization of fifteen US coals of rank ranging from anthracite to sub-bituminous B and five high-temperature chars by carbon monoxide and other gases and gas mixtures between 400 and 600 °C has been studied. The sulphur content of the parent coals ranged between 3.0 and 7.3% and that of the chars between 1.3 and 3.8% by weight. A comparison between air, nitrogen, carbon monoxide, and steam-carbon monoxide mixtures as desulphurizing gases shows the order of desulphurizing ability as . 相似文献
13.
Nagavarapu Sarat Chandra Vachhani Leena Sinha Arpita Buriuly Somnath 《International Journal of Control, Automation and Systems》2021,19(1):491-504
International Journal of Control, Automation and Systems - The system of multiple agents working in coordination for a given task has several advantages on faster completion, fault-tolerance, etc.... 相似文献
14.
Wenjuan Zhu Anup M. Vader Abhinav Chadda Ming C. Leu Xiaoqing F. Liu Jonathan B. Vance 《Virtual Reality》2013,17(2):125-136
This paper describes the development of a Wii remote (Wiimote)–based low-cost motion capture system and demonstrates its application for automated assembly simulation. Multiple Wiimotes are used to form a vision system to perform motion capture in 3D space. A hybrid algorithm for calibrating a multi-camera stereo vision system has been developed based on Zhang’s and Svoboda’s calibration algorithms. This hybrid algorithm has been evaluated and shown accuracy improvement over Svoboda’s algorithm for motion capture with multiple cameras. The captured motion data are used to automatically generate an assembly simulation of objects represented by CAD models in real time. The Wiimote-based motion capture system is practically attractive because it is inexpensive, wireless, and easily portable. Application examples have been developed for a single vision system with two Wiimotes to track the assembly of a microsatellite prototype frame and for an integrated vision system with four Wiimotes to track the assembly of a bookshelf. 相似文献
15.
Detailed Real-Time Urban 3D Reconstruction from Video 总被引:2,自引:0,他引:2
M. Pollefeys D. Nistér J.-M. Frahm A. Akbarzadeh P. Mordohai B. Clipp C. Engels D. Gallup S.-J. Kim P. Merrell C. Salmi S. Sinha B. Talton L. Wang Q. Yang H. Stewénius R. Yang G. Welch H. Towles 《International Journal of Computer Vision》2008,78(2-3):143-167
The paper presents a system for automatic, geo-registered, real-time 3D reconstruction from video of urban scenes. The system
collects video streams, as well as GPS and inertia measurements in order to place the reconstructed models in geo-registered
coordinates. It is designed using current state of the art real-time modules for all processing steps. It employs commodity
graphics hardware and standard CPU’s to achieve real-time performance. We present the main considerations in designing the
system and the steps of the processing pipeline. Our system extends existing algorithms to meet the robustness and variability
necessary to operate out of the lab. To account for the large dynamic range of outdoor videos the processing pipeline estimates
global camera gain changes in the feature tracking stage and efficiently compensates for these in stereo estimation without
impacting the real-time performance. The required accuracy for many applications is achieved with a two-step stereo reconstruction
process exploiting the redundancy across frames. We show results on real video sequences comprising hundreds of thousands
of frames. 相似文献
16.
Sagar Chaki Edmund Clarke Natasha Sharygina Nishant Sinha 《Formal Methods in System Design》2008,32(3):235-266
This paper presents an automated and compositional procedure to solve the substitutability problem in the context of evolving software systems. Our solution contributes two
techniques for checking correctness of software upgrades: (1) a technique based on simultaneous use of over-and under-approximations
obtained via existential and universal abstractions; (2) a dynamic assume-guarantee reasoning algorithm—previously generated component assumptions are reused and altered on-the-fly to prove
or disprove the global safety properties on the updated system. When upgrades are found to be non-substitutable, our solution
generates constructive feedback to developers showing how to improve the components. The substitutability approach has been
implemented and validated in the ComFoRT reasoning framework, and we report encouraging results on an industrial benchmark.
This is an extended version of a paper, Dynamic Component Substitutability Analysis, published in the Proceedings of the Formal Methods 2005 Conference, Lecture Notes in Computer Science, vol. 3582, by the
same authors. This research was sponsored by the National Science Foundation under grant nos. CNS-0411152, CCF-0429120, CCR-0121547,
and CCR-0098072, the Semiconductor Research Corporation under grant no. TJ-1366, the US Army Research Office under grant no.
DAAD19-01-1-0485, the Office of Naval Research under grant no. N00014-01-1-0796, the ICAST project and the Predictable Assembly
from Certifiable Components (PACC) initiative at the Software Engineering Institute, Carnegie Mellon University. The views
and conclusions contained in this document are those of the authors and should not be interpreted as representing the official
policies, either expressed or implied, of any sponsoring institution, the US government or any other entity. 相似文献
17.
Creep experiments were conducted on ice crystals in compression to investigate the effects of boundary conditions on a single-slip system deformed in plane strain. Friction at the platens of the deformation apparatus introduces a bending moment which causes a variation in the amount of lattice rotation across the specimen. This is shown to occur in mechanically constrained crystals observed through plane polarized light. Relieving the constraints and minimizing friction at the ice-platen contact leads to the widening of the sample near the specimen-platen interface and the production of tails symmetrically disposed about the longitudinal axis of the deformed crystals. This is interpreted to originate from a bending moment in the opposite sense from that obtained in the constrained crystals, resulting from a progressive increase in slip displacement towards the platens where the segments of the slip plane become shorter. When the crystal ends were constrained but allowed to move sideways, a simple shear regime was established in which lattice slip was concentrated in the centre of the crystal. 相似文献
18.
This paper illustrates the applicability of neural networks in classifying events using Space Acceleration Measurement System (SAMS) data. Computer programs have been written in the MATLAB environment for the following purposes: automatic retrieval of SAMS data from NASA CDROM disks, computation of power spectral densities for SAMS data and construction of input patterns for the training of a multi-layer neural network (MNN). The MNN has been trained using the backpropagation learning algorithm and the SAMS data collected on the STS-50 Space Shuttle mission for three crew exercise events. It is found that the trained MNN is highly successful in classifying events. In addition, the performance of MNN is found to be better than that of the nearest neighbor classifier. 相似文献
19.
Amit GaurAuthor Vitae Abhinav PrakashAuthor VitaeSaugat JoshiAuthor Vitae Dharma P. Agrawal 《Journal of Parallel and Distributed Computing》2010
The varying degree of mobility of Mesh Clients has provided much more flexibility in Wireless Mesh Networks, and establishing an Authentic Association among entities is a non-trivial problem. In this paper, we introduce a Polynomial Based scheme which provides pair-wise connectivity, low communication, marginal storage overhead and high scalability while making on the fly Authentic Association feasible. The proposed scheme is also observed to be resilient against both traffic analysis and node capture attacks. 相似文献
20.
Sudipta N. Sinha Jan-Michael Frahm Marc Pollefeys Yakup Genc 《Machine Vision and Applications》2011,22(1):207-217
This paper describes novel implementations of the KLT feature tracking and SIFT feature extraction algorithms that run on
the graphics processing unit (GPU) and is suitable for video analysis in real-time vision systems. While significant acceleration
over standard CPU implementations is obtained by exploiting parallelism provided by modern programmable graphics hardware,
the CPU is freed up to run other computations in parallel. Our GPU-based KLT implementation tracks about a thousand features
in real-time at 30 Hz on 1,024 × 768 resolution video which is a 20 times improvement over the CPU. The GPU-based SIFT implementation
extracts about 800 features from 640 × 480 video at 10 Hz which is approximately 10 times faster than an optimized CPU implementation. 相似文献