全文获取类型
收费全文 | 186篇 |
免费 | 8篇 |
国内免费 | 6篇 |
专业分类
化学 | 82篇 |
力学 | 19篇 |
数学 | 34篇 |
物理学 | 24篇 |
无线电 | 41篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 5篇 |
2014年 | 11篇 |
2013年 | 18篇 |
2012年 | 15篇 |
2011年 | 16篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 21篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 2篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有200条查询结果,搜索用时 15 毫秒
51.
Substrate current and degradation of n-channel polycrystalline silicon thin-film transistors 总被引:1,自引:1,他引:0
N.A. Hastas N. Archontas C.A. Dimitriadis G. Kamarinos T. Nikolaidis N. Georgoulas A. Thanailakis 《Microelectronics Reliability》2005,45(2):341-348
Experimental investigation of the substrate current Isub as a function of the gate voltage has been performed in n-channel polycrystalline silicon thin-film transistors (polysilicon TFTs), considering the drain voltage as a parameter of the study. At low gate voltages, Isub exhibits a peak located close to the threshold voltage of the transistor due to hot-carriers generated by impact ionization. At higher gate voltages, Isub increases monotonically with increasing the gate voltage, which is attributed to the temperature rise owing to self-heating. The degradation behavior of polysilicon TFTs, stressed under two different gate and drain bias conditions that cause the same substrate current due to hot-carrier and self-heating effects, is investigated. 相似文献
52.
J. Antonios N. Ginot C. Batard Y. Scudeller M. Machmoum 《Microelectronics Journal》2012,43(6):345-352
This paper presents a model reduction approach for constructing lumped RC thermal networks of IGBT-modules of inverters for which heat and subsequent temperature increases vary with time on different scales ranging from nanosecond to second. It was observed that the time-dependent heat and temperature profiles of transistors and diodes of IGBT-modules of inverters oscillate at two frequencies, one in the range 0.1–50 Hz corresponding to the load current modulation, and the other in the range 1–20 kHz corresponding to the switching frequency. The reduction approach consisted of decomposing the module into different elements, each being described with a number of RC cells selected according to the time-constant of the element with regard to the module. The lumped RC thermal networks were found in good agreement with the continuous model by offering a considerably lower computational time on the different time scales. For simplicity, the reduction approach is presented for one-dimensional heat flow through the cross-plane direction of the module. 相似文献
53.
Antonios Alexiou Dimitrios Antonellis Christos Bouras 《International Journal of Communication Systems》2007,20(1):65-81
This paper proposes a mechanism for the congestion control for video transmission over universal mobile telecommunications system (UMTS). Our scheme is applied when the mobile user experiences real‐time multimedia content and adopts the theory of a widely accepted rate control method in wired networks, namely equation‐based rate control. In this approach, the transmission rate of the multimedia data is determined as a function of the packet loss rate, the round trip time and the packet size and the server explicitly adjusts its sending rate as a function of these parameters. Furthermore, we examine the performance of the UMTS for real‐time video transmission using real‐time protocols. Through a number of experiments, we measure performance parameters such as end‐to‐end delay, delay in radio access network, delay jitter and throughput in the wireless link. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
54.
Antonios D. Melas 《Advances in Mathematics》2005,192(2):310-340
For each p>1 we precisely evaluate the main Bellman functions associated with the dyadic maximal operator on and the dyadic Carleson imbedding theorem. Actually, we do that in the more general setting of tree-like maximal operators. These provide refinements of the sharp Lp inequalities for those operators. For this we introduce an effective linearization for such maximal operators on an adequate set of functions. 相似文献
55.
The exact best possible range of p is determined such that anydyadic A1 weight w on Rn satisfies a reverse Hölder inequalityfor p, which depends on the dimension n and the correspondingA1 constant of w. The proof is based on an effective linearizationof the dyadic maximal operator applied to dyadic step functions.2000 Mathematics Subject Classification 42B25. 相似文献
56.
Antonios Broumas 《Proceedings of the American Mathematical Society》2000,128(3):677-681
Let be the Tate curve with canonical differential, . If the characteristic is , then the Hasse invariant, , of the pair should equal one. If , then calculation of leads to a nontrivial separable relation between the coefficients and . If or , Thakur related and via elementary methods and an identity of Ramanujan. Here, we treat uniformly all characteristics via explicit calculation of the formal group law of . Our analysis was motivated by the study of the invariant which is an infinite Witt vector generalizing the Hasse invariant.
57.
The adsorption of atomic hydrogen on the (1 1 1) planes of silicon single crystals is studied by Auger Electron Analysis, using the decrease of the silicon Auger peak heigh as a measure of the hydrogen coverage. The zero coverage sticking coefficient is found to be 3 × 10?4. 相似文献
58.
59.
Antonios D. Melas 《Transactions of the American Mathematical Society》2002,354(8):3263-3273
We will study the centered Hardy-Littlewood maximal operator acting on positive linear combinations of Dirac deltas. We will use this to obtain improvements in both the lower and upper bounds or the best constant in the weak inequality for this operator. In fact we will show that .
60.
Ioannis Gasteratos Antonios Gasteratos Ioannis Andreadis 《The Journal of VLSI Signal Processing》2006,44(1-2):63-78
Noise due to the sensor and the electronics of a camera is an undesirable issue in any machine vision application. Such noise
tends to corrupt images and to obstruct any further analysis. An algorithm to detect and cancel such noise, using statistical
methods, is presented in this paper. The proposed algorithm is an adaptive mean filter, which filters out image regions that
are found to be noise corrupted. The efficiency of the proposed filter was examined both qualitatively and quantitatively,
by software simulation in several noisy conditions. The main advantage of the filter in hand is that it is appropriate for
hardware implementation and can be easily incorporated to smart cameras. The hardware implementation of the filter is also
presented in this paper. This implementation aims at time critical applications such as machine vision, inspection and visual
surveillance.
Ioannis Gasteratos holds a Diploma in Electrical Engineering from the Department of Electrical and Computer Engineering, Democritus University
of Thrace, Greece, 2004. His research interests include digital VLSI design, computer architectures and artificial intelligence.
He is a member of the IEEE, and a member of the Technical Chamber of Greece (TEE).
Antonios Gasteratos is a Lecturer of Robotics in the Department of Production and Management, Democritus University of Thrace, Greece. He holds
a PhD from the Department of Electrical and Computer Engineering, Democritus University of Thrace, Greece, 1999. During 2001–2003
he was a visiting Assistant Professor in the Department of Electrical and Computer Engineering, Democritus Univesrsity of
Thrace. He serves as a reviewer to numerous of Scientific Journals and International Conferences. His research interests are
mainly in computer and robot vision and sensory data fusion. He is a member of the IEEE, the IAPR, the EURASIP, the Hellenic
Society of Artificial Intelligence (SETN) and the Technical Chamber of Greece (TEE).
Ioannis Andreadis received the Diploma Degree from the Department of Electrical & Computer Engineering, DUTH, Greece, in 1983 and the MSc and
PhD Degrees from the University of Manchester Institute of Science & Technology, UK, in 1985 and 1989, respectively. His research
interests are mainly in Intelligent Systems, Machine Vision and VLSI based computing architectures. He joined the Department
of Electrical & Computer Engineering, DUTH in 1993. He is a member of the Editorial Board of the Pattern Recognition Journal,
TEE and IEEE. 相似文献