全文获取类型
收费全文 | 568篇 |
免费 | 17篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 68篇 |
金属工艺 | 16篇 |
机械仪表 | 14篇 |
建筑科学 | 10篇 |
能源动力 | 25篇 |
轻工业 | 56篇 |
水利工程 | 6篇 |
石油天然气 | 4篇 |
无线电 | 92篇 |
一般工业技术 | 78篇 |
冶金工业 | 104篇 |
原子能技术 | 4篇 |
自动化技术 | 102篇 |
出版年
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 24篇 |
2020年 | 15篇 |
2019年 | 5篇 |
2018年 | 17篇 |
2017年 | 30篇 |
2016年 | 25篇 |
2015年 | 10篇 |
2014年 | 24篇 |
2013年 | 48篇 |
2012年 | 28篇 |
2011年 | 26篇 |
2010年 | 28篇 |
2009年 | 24篇 |
2008年 | 15篇 |
2007年 | 16篇 |
2006年 | 16篇 |
2005年 | 22篇 |
2004年 | 18篇 |
2003年 | 15篇 |
2002年 | 8篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 25篇 |
1997年 | 11篇 |
1996年 | 21篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1969年 | 2篇 |
1964年 | 2篇 |
1963年 | 1篇 |
1957年 | 1篇 |
1956年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有588条查询结果,搜索用时 15 毫秒
1.
Harizi Riadh Walha Rim Drira Fadoua Zaied Mourad 《Multimedia Tools and Applications》2022,81(3):3091-3106
Multimedia Tools and Applications - Text recognition in the wild is a challenging task in the field of computer vision and machine learning. Existing optical character recognition engines cannot... 相似文献
2.
The 3D structure electromagnetic computation presents several difficulties related to the volume mesh. In fact, the entire volume space must be taken into account even the smallest details. In this article, we propose a formulation based on the reciprocity theorem combined with the generalized equivalent circuit method to model a planar 3D structure with both coaxial and planar excitation. The major advantage of this formulation is the fact to reduce the computational volume into 2D ones in the discontinuity plane. In addition, we focused on the calculation of the discontinuity between the excitation source and the planar structure to determine the exact behavior of the electric coaxial excitation model. The obtained current density, electric field distributions, and the input impedance are presented and discussed in the following sections. An approximately good agreement of input impedance with those obtained by the simulator and measurement is shown. 相似文献
3.
Stormwater quality simulation models are useful tools for the design and management of sewer systems. Modelling results are highly sensitive to experimental data used for calibration. This sensitivity is examined for three modelling approaches of various complexities (site mean concentration approach, event mean concentration approach and build-up, washoff and transport modelling approach) applied to a typical case study (design of a dry detention tank), accounting for the variability of calibration data and their effect on simulation results. Calibrated models with different calibration data sets were used to simulate 3 years of rainfall with different retention tank specific volumes. Annual pollutant load interception efficiencies were determined. Simulations results revealed (i) that there is no advantage in using the EMC model compared to the SMC model and (ii) that the BWT model resulted in higher design ratios than those given by the SMC/hydraulic approach. For both EMC and BWT models, using an increasing number n of events for calibration leads to narrower confidence intervals for the design ratios. It is crucial for design ratios to account for successive storm events in chronological order and to account for the maximum allowable flow to be transferred to the downstream WWTP. 相似文献
4.
The purpose of this study was to determine whether retention of fetal lung liquid is more prevalent in polyalveolar congenital lobar emphysema than in conventional congenital lobar emphysema. Two patients with congenital lobar emphysema were prospectively identified in a 3-year period. Twenty-five such patients were identified in a retrospective study covering 39 years. Medical records were available for 22 patients who had 23 emphysematous lobes. Both babies from the prospective study and six subjects from the retrospective group had respiratory symptoms and underwent chest X-ray in the first day of life. Six of the eight babies with respiratory symptoms and chest imaging in the first day of life had retention of fetal lung liquid in an emphysematous lobe. All six of these lobes were polyalveolar. The lobe in one child was a polyalveolar lobe but without retained fetal lung liquid, and one child exhibited conventional lobar emphysema also without retained fetal lung liquid. One polyalveolar lobe caused no neonatal symptoms and was not imaged until the child was 3 months old. No baby with conventional lobar emphysema was shown to have retained fetal lung liquid. There seems to be a correlation between polyalveolar lobe and onset of respiratory symptoms in the first day of life. Retention of fetal lung liquid within the affected lobe was documented only in cases of polyalveolar lobe. 相似文献
5.
6.
Multi-User MIMO Mobile CDMA Uplink System Employing Turbo Coding and Joint Detection Through a Multipath Rayleigh Fading Channel 总被引:1,自引:1,他引:0
Yasmine A. Fahmy Hebat-Allah M. Mourad Emad K. Al-Hussaini 《Wireless Personal Communications》2006,38(3):325-341
In this paper, a generalized multiple-input multiple-output (MIMO) antenna system that can be fitted to the uplink of a wireless communication system is considered for the general case of multi-user. At the transmitter, the information bits are Turbo coded, then interleaved and passed through a serial-to-parallel converter. The channel is assumed bad urban suffering from multipath Rayleigh fading resulting in inter-symbol and multiple access interferences (ISI and MAI). At the front-end of the receiver, a number of receiving antennas are used followed by a joint multi-user estimator based on the Minimum Mean Square Error Block Linear Equalizer (MMSE-BLE).Computer simulations demonstrate a significant performance improvement in both single user and multi-user cases.This paper depends in parts on that presented at the 11th European Wireless Conference, Cyprus, Nicosia, pp. 187–192, April 2005.
Yasmine A. Fahmy was born in Guiza, Egypt, on June 4, 1976. She received the B.Sc., M.Sc. and Ph.D. degrees in Communication and Electronics engineering from Cairo University, Egypt on 1999, 2001 and 2005 respectively. She is presently an assistant professor at Cairo University, Egypt. Her current field of interest is wireless communication and channel estimation.
Hebat-Allah M. Mourad received her B.Sc., M. Sc. and Ph.D. degrees in electrical communication engineering from Cairo University, Egypt, in 1983, 1987 and 1994 respectively. Since 1983, she has been with the Department of Electronics and Communications, Faculty of Engineering, Cairo University, and is currently associate professor there. Her research interests include optical fiber communications, mobile and satellite communications.
Emad K. Al-Hussaini received his B.Sc degree in Electrical Communication Engineering from Ain-Shams University, Cairo, Egypt, in 1964 and his M.Sc and Ph.D. degrees from Cairo University, Giza, Egypt, in 1974 and 1977, respectively. From 1964 to 1970, he was with the General Egyptian Aeroorganization. Since 1970, he has been with the Department of Electronics and Communications, Faculty of Engineering, Cairo University, and is currently professor there. He was a research fellow at Imperial College, London, UK, and at the Moore School of Electrical Engineering, University of Pennsylvania, Philadelphia, PA, USA, in the academic years 1976/1977 and 1981/1982, respectively. In 1990, he received the Egyptian national encouragement award for outstanding engineering research. He has written several papers for technical international journals and conferences. His research interests include signal processing, fading channel communication, modulation, and cellular mobile radio systems. Dr Al-Hussaini is a senior member of IEEE. He is listed in Marquis Whos Who in the World and in the IBC (International Biographical Center, Cambridge) for outstanding people of the 20th century. 相似文献
7.
Nouioua Mourad Fournier-Viger Philippe Wu Cheng-Wei Lin Jerry Chun-Wei Gan Wensheng 《Applied Intelligence》2021,51(10):6785-6809
Applied Intelligence - High utility itemset mining is a popular pattern mining task, which aims at revealing all sets of items that yield a high profit in a transaction database. Although this task... 相似文献
8.
Farouk Belkadi Nicolas Dremont Alban Notin Nadege Troussier Mourad Messadia 《Annual Reviews in Control》2012,36(2):346-358
The design of complex system requires a lot of interactions between experts and then between numerous Computer Aided X software (CAX) (where X can be Design (CAD), Engineering (CAE), Manufacturing (CAM), etc.). In order to improve the consistency of the whole system design and the related data and information, knowledge crossing the expertises must be tracked and formalized regarding a shared reference. That means that instead of defining a large reference models to which each expert refers to, a light collaborative model is defined enabling to connect data from each expert model to adhoc data from other expert models, following the least commitment principle. In this topic, a new meta-model is proposed in a Model-Driven Engineering approach to manage the integration of heterogeneous experts’ knowledge models in a collaborative process. The structure of the proposed knowledge meta-model is defined taking into account the complexity of knowledge definition and the properties of its components. This meta-model is split in a meta-model of data on one hand and a Collaboration Meta-Model in the other hand, to represent the distinction between the core concepts of knowledge and additional elements serving to represent the relation between these concepts, and between concepts of heterogeneous experts’ models. The proposed meta-model is illustrated on an industrial case study to highlight the way to put it in use, and its interests to enable collaboration between experts throughout the design process. 相似文献
9.
Asmaa A. Zidan Mohammed Al-Hawwas Griffith B. Perkins Ghada M. Mourad Catherine J. M. Stapledon Larisa Bobrovskaya Xin-Fu Zhou Plinio R. Hurtado 《International journal of molecular sciences》2021,22(1)
Elucidation of the biological functions of extracellular vesicles (EVs) and their potential roles in physiological and pathological processes is an expanding field of research. In this study, we characterized USC–derived EVs and studied their capacity to modulate the human immune response in vitro. We found that the USC–derived EVs are a heterogeneous population, ranging in size from that of micro–vesicles (150 nm–1 μm) down to that of exosomes (60–150 nm). Regarding their immunomodulatory functions, we found that upon isolation, the EVs (60–150 nm) induced B cell proliferation and IgM antibody secretion. Analysis of the EV contents unexpectedly revealed the presence of BAFF, APRIL, IL–6, and CD40L, all known to play a central role in B cell stimulation, differentiation, and humoral immunity. In regard to their effect on T cell functions, they resembled the function of mesenchymal stem cell (MSC)–derived EVs previously described, suppressing T cell response to activation. The finding that USC–derived EVs transport a potent bioactive cargo opens the door to a novel therapeutic avenue for boosting B cell responses in immunodeficiency or cancer. 相似文献
10.
Josephine Eskaf William J. Cleveland Matthias L. Riess 《International journal of molecular sciences》2021,22(9)
Myocardial infarction is a leading cause for morbidity and mortality worldwide. The only viable treatment for the ischemic insult is timely reperfusion, which further exacerbates myocardial injury. Maintaining mitochondrial function is crucial in preserving cardiomyocyte function in ischemia reperfusion (IR) injury. Poloxamer (P) 188 has been shown to improve cardiac IR injury by improving cellular and mitochondrial function. The aim of this study was to show if P188 postconditioning has direct protective effects on mitochondrial function in the heart. Langendorff prepared rat hearts were subjected to IR injury ex-vivo and reperfused for 10 min with 1 mM P188 vs. vehicle. Cardiac mitochondria were isolated with 1 mM P188 vs. 1 mM polyethylene glycol (PEG) vs. vehicle by differential centrifugation. Mitochondrial function was assessed by adenosine triphosphate synthesis, oxygen consumption, and calcium retention capacity. Mitochondrial function decreased significantly after ischemia and showed mild improvement with reperfusion. P188 did not improve mitochondrial function in the ex-vivo heart, and neither further P188 nor PEG induced direct mitochondrial protection after IR injury in this model. 相似文献