全文获取类型
收费全文 | 1071篇 |
免费 | 73篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 6篇 |
综合类 | 1篇 |
化学工业 | 233篇 |
金属工艺 | 25篇 |
机械仪表 | 24篇 |
建筑科学 | 55篇 |
矿业工程 | 1篇 |
能源动力 | 36篇 |
轻工业 | 69篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 154篇 |
一般工业技术 | 205篇 |
冶金工业 | 121篇 |
原子能技术 | 5篇 |
自动化技术 | 207篇 |
出版年
2023年 | 8篇 |
2022年 | 14篇 |
2021年 | 30篇 |
2020年 | 20篇 |
2019年 | 22篇 |
2018年 | 26篇 |
2017年 | 38篇 |
2016年 | 57篇 |
2015年 | 35篇 |
2014年 | 46篇 |
2013年 | 68篇 |
2012年 | 66篇 |
2011年 | 74篇 |
2010年 | 53篇 |
2009年 | 56篇 |
2008年 | 51篇 |
2007年 | 49篇 |
2006年 | 33篇 |
2005年 | 31篇 |
2004年 | 23篇 |
2003年 | 35篇 |
2002年 | 17篇 |
2001年 | 11篇 |
2000年 | 10篇 |
1999年 | 12篇 |
1998年 | 49篇 |
1997年 | 32篇 |
1996年 | 27篇 |
1995年 | 11篇 |
1994年 | 10篇 |
1993年 | 13篇 |
1992年 | 15篇 |
1991年 | 6篇 |
1990年 | 14篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 14篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 8篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1973年 | 2篇 |
1954年 | 1篇 |
排序方式: 共有1146条查询结果,搜索用时 31 毫秒
941.
Felix G Hamza-Lup Anand P Santhanam Celina Imielińska Sanford L Meeks Jannick P Rolland 《IEEE transactions on information technology in biomedicine》2007,11(1):40-46
Augmented reality (AR) systems add visual information to the world by using advanced display techniques. The advances in miniaturization and reduced hardware costs make some of these systems feasible for applications in a wide set of fields. We present a potential component of the cyber infrastructure for the operating room of the future: a distributed AR-based software-hardware system that allows real-time visualization of three-dimensional (3-D) lung dynamics superimposed directly on the patient's body. Several emergency events (e.g., closed and tension pneumothorax) and surgical procedures related to lung (e.g., lung transplantation, lung volume reduction surgery, surgical treatment of lung infections, lung cancer surgery) could benefit from the proposed prototype. 相似文献
942.
Abstract: Although neural networks have been successfully used in performing pattern recognition, their application for solving optimization problems has been limited. In this paper we design a neural network to solve a well‐known combinatorial problem, namely the flexible flow shop problem. A key feature of our neural network design is the integration of problem structure and heuristic information in the network structure and solution. We compare the performance of our neural network with well‐known current heuristics with respect to solution quality. The results indicate that our approach outperforms the heuristics. 相似文献
943.
Temperature correction of radiometric and geometric models for an uncooled CCD camera in the near infrared 总被引:1,自引:0,他引:1
Sentenac T. Le Maoultt Y. Rolland G. Devy M. 《IEEE transactions on instrumentation and measurement》2003,52(1):46-60
This paper presents radiometric and geometric models for both temperature and displacement noncontact measurements using an uncooled charge-coupled device (CCD) video camera. Such techniques ("one sensor-two measures") represent an interest in many industrial low cost applications and scientific domains. To benefit from both measurements, we have to use the camera's spectral response in the near infrared spectral band from 0.75 to 1.1 /spl mu/m. In this spectral band, the temperature variations of an uncooled CCD camera are taken into account in the radiometric and geometric models. By using physical models for CCD camera, we quantify detector's quantum efficiency, sensor noise and spatial resolution as a function of the wavelength and of the detector temperature. These models are confirmed by experimental results of calibration with a low cost uncooled camera based on a Sony detector and operating over the detector temperature range of -30 to -50/spl deg/. 相似文献
944.
Worst case response times in a Bluetooth piconet: scheduling combining 1-RR or E-RR with FIFO or EDF
In this paper, we focus on the Bluetooth wireless network, analyzing its ability to support the Quality of Service (QoS) requirements
defined by QoS sensitive applications. The QoS perceived by the application depends on the scheduling mechanisms chosen at
the medium access layer. Hence, we propose to evaluate the ability of different Bluetooth scheduling algorithms (1-RR/FIFO,
1-RR/EDF, E-RR/FIFO and E-RR/EDF) to guarantee bounded transmission delays. First, we establish a bound on the worst case
response time of any sporadic message using a worst case analysis. We then compare the computed bounds with the worst case
response times obtained by simulation for different traffic distributions and show in which configurations our bounds are
tight. We finally compare those different schedulings and show how to extend our results on worst case response times taking
into account message segmentation. 相似文献
945.
946.
B. Arrazat A. Danel S. Favier F. Nemouchi G. Rolland O. Kermarrec S. Descombes 《Microelectronic Engineering》2007,84(11):2558-2562
Very efficient in particles detection, light scattering also offers fast non-invasive full-mapping wafer surface state. This sensitivity was used in the case of germano-silicide process development. As a matter of fact, we report on haze measurement performances, compared to the usual methods used to investigate thermal stability of Ni(Si1−xGex), such as sheet resistance (SR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). We observed defectivity related to thermal agglomeration and Ge-segregation of Ni(Si1−xGex) on strain Si1−xGex (x ? 30%) by haze measurement (like SEM observations) earlier than SR measurement. Moreover, we noticed that a high Ge content affects at lower temperature the stability of Ni(Si1−xGex) with a segregation phenomena. 相似文献
947.
Elodie Arnaud Perla Relkin Michel Pina Antoine Collignan 《European Journal of Lipid Science and Technology》2004,106(9):591-598
Chicken fat was processed by dry fractionation to obtain a solid fraction at ambient temperature. Crystallisation and separation were performed using industrial‐type procedures. Crystal formation and changes were monitored, while determining the composition, physical characteristics and thermal behaviour of the initial fat and resulting fractions. Dry fractionation, under the described conditions, produced stearin that resembled other animal fats such as lard and tallow and with better physical features than the initial fat stock. The results of this study also highlighted the mechanisms involved during the dry fractionation process. 相似文献
948.
Philippe Gravey Jean -Louis de Bougrenet de la Tocnaye Bruno Fracasso Nicole Wolffer Antoine Tan Bruno Vinouze Mustapha Razzak Amal Kali 《电信纪事》2003,58(9-10):1378-1400
This paper addresses the issue of using conventional liquid crystal materials as reconfigurable holographic or diffractive phase elements within optical space switches and the resulting constraints in their choice and use in a telecommunication environment. We discuss the advantage of this technology for implementing holographic-based approaches with respect to other techniques. As an illustration we give two examples which illustrate two generic architectures and complementary use of liquid crystal to implement them. Finally, we give some trends on implementations of high channel capacity space switches based on this technology. 相似文献
949.
In this article, we advocate the use of mode automata as a high level representation language for reliability studies. Mode automata are states/transitions based representations with the additional notion of flow. They can be seen as a generalization of both finite capacity Petri nets and block diagrams. They can be assembled into hierarchies by means of composition operations.The contribution of this article is twofold. First, we introduce mode automata and we discuss their relationship with other formalisms. Second, we propose an algorithm to compile mode automata into Boolean equations (fault trees). Such a compilation is of interest for two reasons. First, assessment tools for Boolean models are much more efficient than those for states/transitions models. Second, the automated generation of fault trees from higher level representations makes easier their maintenance through the life cycle of systems under study. 相似文献
950.
Manufacturing, fabrication, and transportation limitations make it impossible to provide full length continuous bars in some reinforced concrete structures. In general, reinforcing bars are stocked by suppliers in lengths of 12–18 m. For that reason, and because it is often more convenient to work with shorter bar lengths, it is frequently necessary to splice bars in the field. 相似文献