全文获取类型
收费全文 | 178篇 |
免费 | 17篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 2篇 |
综合类 | 2篇 |
化学工业 | 31篇 |
金属工艺 | 2篇 |
机械仪表 | 14篇 |
建筑科学 | 5篇 |
矿业工程 | 1篇 |
能源动力 | 2篇 |
轻工业 | 7篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 44篇 |
一般工业技术 | 48篇 |
冶金工业 | 8篇 |
原子能技术 | 5篇 |
自动化技术 | 23篇 |
出版年
2023年 | 7篇 |
2022年 | 2篇 |
2021年 | 12篇 |
2020年 | 10篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 9篇 |
2016年 | 3篇 |
2015年 | 12篇 |
2014年 | 7篇 |
2013年 | 13篇 |
2012年 | 15篇 |
2011年 | 16篇 |
2010年 | 8篇 |
2009年 | 9篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 7篇 |
2005年 | 3篇 |
2004年 | 8篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 3篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有196条查询结果,搜索用时 0 毫秒
1.
Image enhancement using the modified ICM method 总被引:6,自引:0,他引:6
A generalized version of the iterative conditional modes (ICM) method for image enhancement is developed. The proposed algorithm utilizes the characteristic of Markov random fields (MRF) in modeling the contextual information embedded in image formation. To cope with real images, a new local MRF model with a second-order neighborhood is introduced. This model extracts contextual information not only from the intensity levels but also from the relative position of neighboring cliques. Also, an outlier rejection method is presented. In this method, the rejection depends on each candidate's contribution to the local variance. To cope with a mixed noise case, a hypothesis test is implemented as part of the restoration procedure. The proposed algorithm performs signal adaptive, nonlinear, and recursive filtering. In comparing the performance of the new procedure with several well-known order statistic filters, the superiority of the proposed algorithm is demonstrated both in the mean-square-error (MSE) and the mean-absolute-error (MAE) senses. In addition, the new algorithm preserves the details of the images well. It should be noted that the blurring effect is not considered. 相似文献
2.
During the last decade, a plentiful number of active queue management schemes have been proposed, but their main objectives are simply allocating the buffer resource to all flows evenly, or protecting responsive flows from being degraded by unresponsive flows. However, the sending rates of the responsive flows can be determined diversely, and not all unresponsive flows have aggressively high sending rates. Furthermore, it is rational to reserve a portion of the buffer resource for certain privileged traffic. Grounded by these evidences, in this paper, we present a resilient active queue management algorithm, named Prior‐Core‐based Buffer Allocation considering diverse congestion control algorithms, fair‐unresponsive flows, and some privileged traffic. Our approach is based on stochastic cooperative game theory, where the payoffs yielded by cooperation are described by random variables, and the core is defined only over the distribution of these random payoffs; the core in this situation is called the prior‐core. As a result, it is shown that our buffer allocation, yielded by the prior‐core, achieves completely fair allocation for those flows whose requirement does not exceed the fair‐share regardless of the responsiveness, whereas aggressive flows are restricted according to availability of the buffer; all these are verified through ns‐2 simulation experiments. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
3.
Jaeyoung Jang Sooji Nam Kyuhyun Im Jaehyun Hur Seung Nam Cha Jineun Kim Hyung Bin Son Hwansoo Suh Marsha A. Loth John E. Anthony Jong‐Jin Park Chan Eon Park Jong Min Kim Kinam Kim 《Advanced functional materials》2012,22(5):1005-1014
The preparation of uniform large‐area highly crystalline organic semiconductor thin films that show outstanding carrier mobilities remains a challenge in the field of organic electronics, including organic field‐effect transistors. Quantitative control over the drying speed during dip‐coating permits optimization of the organic semiconductor film formation, although the kinetics of crystallization at the air–solution–substrate contact line are still not well understood. Here, we report the facile one‐step growth of self‐aligning, highly crystalline soluble acene crystal arrays that exhibit excellent field‐effect mobilities (up to 1.5 cm V?1 s?1) via an optimized dip‐coating process. We discover that optimized acene crystals grew at a particular substrate lifting‐rate in the presence of low boiling point solvents, such as dichloromethane (b.p. of 40.0 °C) or chloroform (b.p. of 60.4 °C). Variable‐temperature dip‐coating experiments using various solvents and lift rates are performed to elucidate the crystallization behavior. This bottom‐up study of soluble acene crystal growth during dip‐coating provides conditions under which one may obtain uniform organic semiconductor crystal arrays with high crystallinity and mobilities over large substrate areas, regardless of the substrate geometry (wafer substrates or cylinder‐shaped substrates). 相似文献
4.
Pilot‐based coding (PBC), which is used for lossless bit rate reduction of audio coding, has been recently proposed for MPEG Surround. We propose extended PBC for further lossless bit rate reduction of MPEG Surround. Extended PBC selects the number of pilots depending on the parameter band number and the type of spatial parameter. It then encodes the pilots and the relevant difference data. Experiments show that extended PBC is more effective than the original PBC, especially for high bit rate modes, with a negligible complexity increase on the decoder side. 相似文献
5.
C.W. Jeong D.H. Kang D.W. Ha Y.J. Song J.H. Oh J.H. Kong J.H. Yoo J.H. Park K.C. Ryoo D.W. Lim S.S. Park J.I. Kim Y.T. Oh J.S. Kim J.M. Shin Jaehyun Park Y. Fai G.H. Koh G.T. Jeong H.S. Jeong Kinam Kim 《Solid-state electronics》2008,52(4):591-595
We evaluated the limit of scaling bottom electrode contact (BEC) heater size and high resistivity heater to reduce writing current. It was found that the resistivity of heater should be increased for reducing writing current below the heater size of about 50 nm without any undesirable increase of resistance of the crystalline state (SET state, Rset). It was shown in the numerical simulations that the dissipated heat loss through BEC during melting GST was decreased in the increase of resistivity of heater. In addition, we analyzed the resistance components contributing to the total set resistance. It was observed that the undesired sharp increase of Rset as the BEC size decreases below 50 nm was attributed to the resistance component of GST–BEC interface. In the case of high resistivity heater, the contributions of both incomplete crystallization and heater itself were enhanced. 相似文献
6.
Seung‐Kyun Kang Suk‐Won Hwang Sooyoun Yu Jung‐Hun Seo Elise A. Corbin Jiho Shin Dae Seung Wie Rashid Bashir Zhenqiang Ma John A. Rogers 《Advanced functional materials》2015,25(12):1789-1797
Biodegradable substrates and encapsulating materials play critical roles in the development of an emerging class of semiconductor technology, generally referred as “transient electronics”, whose key characteristic is an ability to dissolve completely, in a controlled manner, upon immersion in ground water or biofluids. The results presented here introduce the use of thin foils of Mo, Fe, W, or Zn as biodegradable substrates and silicate spin‐on‐glass (SOG) materials as insulating and encapsulating layers, with demonstrations of transient active (diode and transistor) and passive (capacitor and inductor) electronic components. Complete measurements of electrical characteristics demonstrate that the device performance can reach levels comparable to those possible with conventional, nontransient materials. Dissolution kinetics of the foils and cytotoxicity tests of the SOG yield information relevant to use in transient electronics for temporary biomedical implants, resorbable environmental monitors, and reduced waste consumer electronics. 相似文献
7.
Jaehyun Park Se Hun Joo Yoon‐Jeong Kim Ju Hyun Park Sang Kyu Kwak Seokhoon Ahn Seok Ju Kang 《Advanced functional materials》2019,29(32)
In this work, a highly conductive organic cocrystal is investigated as an anode material for conducting agent‐free lithium‐ion battery (LIB) electrodes. A unique morphology of semiconducting fullerene (C60) and contorted hexabenzocoronene (cHBC) is developed as a cocrystal that efficiently enhances the electron transfer during discharge and charge processes due to the formation of a well‐defined junction between C60 and cHBC. In particular, the present study reveals the exact cocrystal phase of orthorhombic Pnnm using grazing incidence X‐ray diffraction characterization and computational methods. The detailed cocrystal structure analysis indicates that the columnar structure of C60/cHBC cocrystal facilitates the reliable vacant sites for Li+ storage, which ultimately enhances the reversible capacity to 330 mAh g–1 at 0.1 A g–1 with long cyclability of 600 cycles in the absence of a conducting agent. Furthermore, the rate performance of the C60/cHBC cocrystal anode is improved compared to that of the graphite anode, indicating that the cocrystal formation between C60 and cHBC enhances the charge transport at a high current density. It demonstrates that the approach of this study can be a promising strategy for preparing conducting agent‐free organic cocrystal anodes, which also provides a viable design rule for high‐performance LIBs electrodes. 相似文献
8.
We perform systematic study on the jetting performance of electrohydrodynamic (EHD) with an insulating polymers such as polystyrene (PS) and poly(methyl methacrylate) (PMMA). EHD printing applies electrostatic field to ink droplet hang on nozzle tip, which causes the deformation of the meniscus to generate discrete droplets or continuous jet stream. Although EHD jetting mechanism has been frequently investigated with conducting or semiconducting materials, there still needs to elucidate EHD jetting of insulating polymer materials for producing controllable droplets. In the present study, we focused on how the physical/chemical properties (conductivity, dielectric constant, and molecular weight) of an insulating polymer affect jetting behavior of EHD printing (especially, the deformation of the meniscus and the corresponding morphology of the printed one). The relationship between the printing parameters and applied voltage is also investigated, thereby allowing the optimization of EHD printings for PS and PMMA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45044. 相似文献
9.
Sungho Woo Jaehyun Kim Gwijeong Cho Kangpil Kim Hongkeun Lyu Youngkyoo Kim 《Journal of Industrial and Engineering Chemistry》2009,15(5):716-718
Here we report the effect of introducing nickel oxide (NiO) on the performance of organic light-emitting devices (OLEDs) based on small molecules. For the purpose of aligning the NiO deposition with the conventional OLED process, we employed a thermal evaporation method using the NiO powders. To understand the influence of the NiO introduction, we fabricated two types of devices: (1) OLED with the NiO nanolayer and (2) OLED with the NiO-doped hole transport layer. Results show that the NiO introduction improved the hole injection in both types of OLED. However, the device with the NiO nanolayer exhibited greatly improved efficiency, whereas the efficiency was significantly lowered for the device with the NiO-doped hole transport layer. 相似文献
10.
Transient Electronics: Wireless Microfluidic Systems for Programmed,Functional Transformation of Transient Electronic Devices (Adv. Funct. Mater. 32/2015) 下载免费PDF全文