全文获取类型
收费全文 | 238篇 |
免费 | 7篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 23篇 |
化学工业 | 39篇 |
金属工艺 | 5篇 |
机械仪表 | 7篇 |
建筑科学 | 4篇 |
矿业工程 | 1篇 |
能源动力 | 22篇 |
轻工业 | 7篇 |
水利工程 | 3篇 |
石油天然气 | 2篇 |
无线电 | 34篇 |
一般工业技术 | 47篇 |
冶金工业 | 2篇 |
原子能技术 | 3篇 |
自动化技术 | 52篇 |
出版年
2023年 | 12篇 |
2022年 | 13篇 |
2021年 | 13篇 |
2020年 | 13篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 14篇 |
2015年 | 14篇 |
2014年 | 13篇 |
2013年 | 21篇 |
2012年 | 13篇 |
2011年 | 13篇 |
2010年 | 16篇 |
2009年 | 11篇 |
2008年 | 15篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 3篇 |
2004年 | 7篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1998年 | 5篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1992年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1972年 | 1篇 |
1967年 | 2篇 |
排序方式: 共有251条查询结果,搜索用时 15 毫秒
41.
Mustapha El HANINE ;Elhassane ABDELMOUNIM ;Rachid HADDADI ;Abdelaziz BELAGUID 《计算机技术与应用:英文》2014,(2):98-104
The most common noises in ECG (electrocardiogram) signal processing are BW (baseline wandering) and the 50 or 60 Hz PLI (power line interferences). In order to remove these two major source of noises, we have used the recent powerful DWT (discrete wavelet transform) signal processing in ECG signals which are obtained from MIT-BIH Arrhythmia Database. The results indicate that DWT is a good method for filtering noises without changing the morphology of ECG, and can be applied to all types of ECG signals, whether normal or presenting arrhythmias. 相似文献
42.
The filling level (W) dependence of the local structure of MnCl2 through the PVDF matrix was explored. The presence of α- and β-PVDF crystalline phases were detected by X-ray diffraction, and it was confirmed by the infrared (IR) absorption spectra. A significant head-to-head content was implied by IR spectroscopy. Two filling, level-dependent optical energy gaps were found through the UV–VIS spectral investigation. An intrachain one-dimensional interpolaron hopping mechanism was assumed to proceed in the temperature range of 350–375 K. The calculated values of the charge carrier hopping distance were in the range of 6.5–9.7 nm. The temperature dependence of the direct current (dc) magnetic susceptibility exhibited a Curie–Weiss behavior. Positive values of the paramagnetic Curie temperature (θp) for W up to 14.5% indicated the presence of a ferromagnetic interaction, while negative θp obtained for higher W values suggested an antiferromagnetic interaction at lower temperature. The electron spin resonance (ESR) analysis revealed the existance of both isolated and aggregated Mn2+ ions within the PVDF matrix. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1437–1445, 1998 相似文献
43.
This article presents an efficient meta-heuristic method for reconfiguration of distribution systems. A modified Tabu Search (MTS) algorithm is used to reconfigure distribution systems so that active power losses are globally minimized with turning on/off sectionalizing switches. TS algorithm is introduced with some modifications such as using a tabu list with variable size according to the system size. Also, a random multiplicative move is used in the search process to diversify the search toward unexplored regions. The Kirchhoff algebraic method is adopted to check the radial topology of the system. A salient feature of the MTS method is that it can quickly provide a global optimal or near-optimal solution to the network reconfiguration problem. To verify the effectiveness of the proposed approach, the effect of load variation is taken into consideration and comparative studies are conducted on three test systems with rather encouraging results. The obtained results, using the proposed MTS approach, are compared with that obtained using other approaches in the previous work. 相似文献
44.
This paper deals with a numerical analysis of the evaporation of binary liquid film. The film is falling down on one plate of a vertical channel under mixed convection channel. The first plate of a vertical channel is externally submitted to a uniform heated flux q1 while the second one (y = d) is dry and isothermal. The liquid mixture consists of water (the more volatile component) and ethylene glycol while the gas mixture has three components: dry air, water vapour and ethylene-glycol vapour. The results concern the effects of the inlet parameters in the gas and in the liquid film on the interfacial pressure, temperature and concentration profiles. The evolutions of the heat fluxes and of the water and mixture evaporation rates have been analysed. Results obtained show, in particular, that it is possible to increase the accumulated evaporation rate of water and of the liquid mixture when the inlet liquid concentration of ethylene glycol (the less volatile component) is less than 40%. This result has been explained by the fact that an increase of the inlet liquid concentration of ethylene glycol has two antagonistic effects on the accumulated evaporation rates of water and of liquid mixture. 相似文献
45.
Yassine Kharbouch Abdelaziz Mimet Mohammed El Ganaoui Lahoucine Ouhsaine 《国际可持续能源杂志》2018,37(6):515-532
This study investigates the thermal energy potentials and economic feasibility of an air-conditioned family household-integrated phase change material (PCM) considering different climate zones in Morocco. A simulation-based optimisation was carried out in order to define the optimal design of a PCM-enhanced household envelope for thermal energy effectiveness and cost-effectiveness of predefined candidate solutions. The optimisation methodology is based on coupling Energyplus® as a dynamic simulation tool and GenOpt® as an optimisation tool. Considering the obtained optimum design strategies, a thermal energy and economic analysis are carried out to investigate PCMs’ integration feasibility in the Moroccan constructions. The results show that the PCM-integrated household envelope allows minimising the cooling/heating thermal energy demand vs. a reference household without PCM. While for the cost-effectiveness optimisation, it has been deduced that the economic feasibility is stilling insufficient under the actual PCM market conditions. The optimal design parameters results are also analysed. 相似文献
46.
Ebtessam A. Essa Aya R. Elbasuony Abdelaziz E. Abdelaziz Gamal M. El Maghraby 《Drug development and industrial pharmacy》2013,39(8):1215-1223
Objectives: Enhance the dissolution rate of bicalutamide via co-crystallization with sucralose (sweetener), with the aim to develop rapidly disintegrating tablets with subsequent prompt dissolution.Significance: Bicalutamide is antiandrogenic agent for the treatment of prostate cancer but has low and variable oral bioavailability, mainly attributed to poor dissolution. Co-crystallization with benign excipients is promising for dissolution enhancement with the additive serving dual functions. The benefit will become greater if dissolution enhancement is associated with the development of orodispersible tablets which is suitable for elderly patients who are the most vulnerable for prostate cancer.Methods: Bicalutamide was dissolved in acetone in the presence of increasing molar ratios of sucralose. The solvent was evaporated while mixing to deposit crystals that were subjected to wet co-grinding until drying. The developed solids were characterized using Fourier transform infrared spectroscopy, differential thermal analysis and X-ray diffraction in addition to monitoring bicalutamide dissolution.Results: Instrumental analysis provided evidences for co-crystallization which was initiated at 1:1 molar ratio of bicalutamide to sucralose with complete co-crystallization at 1:4 molar ratio. The co-crystals provided faster bicalutamide dissolution compared with the unprocessed drug and that recrystalized from acetone in the absence of sucralose. The formulation containing bicalutamide with sucralose at 1:4 molar ratio was selected for tablet formulation into which superdisintegrants were included. The developed tablets exhibited flash disintegration with subsequent fast dissolution of bicalutamide.Conclusions: The study introduced co-crystallization of bicalutamide with sucralose as an efficient tool to enhance the dissolution rate and to develop rapidly dissolving tablets for intraoral administration. 相似文献
47.
José Antonio Cayuela Mirela Rada María del Carmen Pérez‐Camino Mohamed Benaissa Elamrani Abdelaziz Ángeles Guinda 《European Journal of Lipid Science and Technology》2008,110(12):1159-1166
The present study was conducted to know the possible influence of the seed treatment, method of extraction and geographical origin on the quality and chemical composition of argan oil. Artisanally and semiautomatically extracted argan oils, from roasted and unroasted seeds, from interior and coast areas, were studied. The quality parameters analyzed were acid value, peroxide value, K232 and K270, triacylglycerols and fatty acid composition, polar compounds, total phenols, tocopherol content and oil stability index (OSI). Seed treatment and extraction method showed a higher influence on quality parameters than geographical area; the quality parameters of the different oils were discussed. The total phenolic content in all analyzed samples was lower than 10 ppm. γ‐Tocopherol was the major tocopherol (84.4–86.4%) with a high contribution to the total tocopherol content (383–485 ppm). The OSI of the argan oil samples were well correlated (R = 0.97) with the tocopherol contents. The argan oil samples obtained from roasted seeds presented higher stability (26–38 h) than the oils from unroasted seeds (16–32 h). 相似文献
48.
Syed Zubair Ahmad Muhammad Abdul Qadir Muhammad Saeed Akbar Abdelaziz Bouras 《Wireless Personal Communications》2012,63(1):177-197
Multi-server scheduling of traffic flows over heterogeneous wireless channels affix fresh concerns of inter-packet delay variations
and associated problems of out-of-sequence reception, buffer management complexity, packet drops and re-ordering overhead.
In this paper, we have presented an exclusive multi-server scheduling algorithm that is specifically tuned for mobile routers
equipped with multiple wireless interfaces and has attained multiple care-of-address registrations with its home agent (HA).
The proposed adaptive, Self-clocked, Multi-server (ASM) scheduling algorithm is based on predetermined transmission deadlines
for each arrived packet at the mobile router. The mobile flows receive desired service levels in accordance with their negotiated
service rates and are only constraint by the cumulative capacity of all active links. The major challenge lies in the handling
of asymmetric channels to stitch into a unified virtual channel of higher capacity with reliable service guarantees during
mobility. The sorted list of transmission schedules is used to assign physical channels in increasing order of their availability.
This approach specifically encapsulates the physical layer disconnections during the handovers and ensures continuous service
to ongoing flows. The proposed scheduling scheme is supplemented by an analytical model and simulations to verify its efficacy.
The simulation results demonstrate higher degree of reliability and scalability of service provisioning to flows during mobility. 相似文献
49.
Halladja S Ter Halle A Aguer JP Boulkamh A Richard C 《Environmental science & technology》2007,41(17):6066-6073
To probe the reactivity of 2,4,6-trimethylphenol with humic triplet excited states, we investigated its influence on the humic substances-mediated photooxygenation offurfuryl alcohol. Elliott soil humic and fulvic acids were employed for these experiments. When added in the concentration range of 10(-4) - 10(-3) M, 2,4,6-trimethylphenol inhibited furfuryl alcohol photooxygenation to an extent depending on its concentration. The inhibiting effect decreased as the oxygen concentration was increased. By postulating that 2,4,6-trimethylphenol competes with oxygen for reaction with humic triplet excited states and with furfuryl alcohol for reaction with singlet oxygen, we obtained kinetic laws describing the consumption profiles of furfuryl alcohol and 2,4,6-trimethylphenol. Experimental rates of 2,4,6-trimethylphenol and furfuryl alcohol loss could be satisfactorily fitted with 1.09-1.16 for the ratio k2/k3, where k2 and k3 are the reaction rate constants of humic triplet excited states with oxygen and 2,4,6-trimethylphenol, respectively. These types of experiments could be extended to a variety of substrates to measure their reaction rate constants with humic triplet excited states. 相似文献
50.
Chakir El-Kasri Abdelaziz Hmamed El Houssaine Tissir Fernando Tadeo 《Multidimensional Systems and Signal Processing》2013,24(4):685-706
This paper deals with the problem of delay-dependent robust $H_{\infty }$ H ∞ filtering for uncertain two-dimensional (2-D) continuous systems described by Roesser state space model with time-varying delays, with the uncertain parameters assumed to be of polytopic type. A sufficient condition for $H_{\infty }$ H ∞ noise attenuation is derived in terms of linear matrix inequalities, so a robust $H_{\infty }$ H ∞ filter can be obtained by solving a convex optimization problem. Finally, some examples are provided to illustrate the effectiveness of the proposed methodology. 相似文献