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排序方式: 共有1495条查询结果,搜索用时 202 毫秒
61.
Taheri Mostafa Zhang Chongqi Berardehi Zahra Rasooli Chen Yucheng Roohi Majid 《Multimedia Tools and Applications》2022,81(17):24167-24197
Multimedia Tools and Applications - Synchronization of different Chaotic dynamical systems is one of the main issues in engineering which has a lot of applications in applied sciences like secure... 相似文献
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Alireza Baghban Amin Piri Mostafa Lakzaei Mohammad Baghban 《Petroleum Science and Technology》2019,37(11):1231-1237
The increasing global energy demand and declination of oil reservoir in recent years cause the researchers attention focus on the enhancement of oil recovery approaches. One of the extensive applicable methods for enhancement of oil recovery, which has great efficiency and environmental benefits, is carbon dioxide injection. The CO2 injection has various effects on the reservoir fluid, which causes enhancement of recovery. One of these effects is extraction of lighter components of crude oil, which straightly depends on solubility of hydrocarbons in carbon dioxide. In order to better understand of this parameter, in this study, Least squares support vector machine (LSSVM) algorithm was developed as a novel predictive tool to estimate solubility of alkane in CO2 as function of carbon number of alkane, carbon dioxide density, pressure, and temperature. The predicting model outputs were compared with the extracted experimental solubility from literature statistically and graphically. The comparison showed the great ability and high accuracy of developed model in prediction of solubility. 相似文献
65.
Mahinzare Mohammad Barooti Mohammad Mostafa Ghadiri Majid 《Microsystem Technologies》2018,24(3):1695-1711
Microsystem Technologies - This article presented a numerical method for discovering the free vibration of a spinning bi-dimensional functionally graded materials (FGM) micro circular plate exposed... 相似文献
66.
Annealed ZnO thin film at 400 °C for two hours was deposited on a glass substrate by using pulsed laser deposition (PLD). The structural properties of the annealed ZnO thin film were studied by XRD, TEM and SEM. Gas sensing properties for different gases such as H2 and LPG were investigated. Applying XRD the size of the nanocrystals is found to be 10.61 nm. SEM of the thin film consisted of many grains distributed uniformly throughout the surface. An annealed ZnO thin film sensor showed the typical n-type semiconducting behavior in the case of H2 and LGP gases at low and high operating temperature range, respectively. When working at 50 and 140 °C the sensor exhibits very good dynamic response–recovery characteristics to H2 and LGP, respectively. These results along with a simple fabrication process demonstrate that the annealed ZnO thin film at 400 °C for two hours is promising for developing low cost and high performance H2 and LPG sensors. The low cost of the sensor element fabrication, high H2 and LPG sensitivity, fast response and quick recovery make the entire fabrication process a front-runner and cost-effective for the production of annealed ZnO thin film H2 and LPG sensors. 相似文献
67.
This study reports an experimental investigation on hydrodynamics and mass transfer characteristics in a 15.6x10-3 m3 external loop airlift reactor for oil-in-water micro-emulsions with oil to water volume ratio (φ) rang- ing from 3% to 7% (by volume). For comparative purposes, experiments were also carried out with water. Increase in φ of micro-emulsion systems results in an increment in the gas holdup and a decrease in the volumetric gas-liquid oxygen transfer coefficient and liquid circulation velocity, attributed to the escalation in the viscosity of mi- cro-emulsions. The gas holdup and volumetric mass transfer coefficient for micro-emulsion systems are signifi- cantly higher than that of water system. Two correlations are developed to predict the gas holdup and oxygen trans- fer coefficient 相似文献
68.
Raqibul Mostafa Ramesh C. Pallat Uwe Ringel Ashok A. Tikku Jeffrey H. Reed 《ETRI Journal》2012,34(3):319-329
Closed‐loop transmit diversity is considered an important technique for improving the link budget in the third generation and future wireless communication standards. This paper proposes several transmit diversity algorithms suitable for small wireless terminals and presents performance assessment in terms of average signal‐to‐noise ratio (SNR) and outage improvement, convergence, and complexity of operations. The algorithms presented herein are verified using data from measured indoor channels with variable antenna spacing and the results explained using measured radiation patterns for a two‐element array. It is shown that for a two‐element array, the best among the proposed techniques provides SNR improvement of about 3 dB in a tightly spaced array (inter‐element spacing of 0.1 wavelength at 2 GHz) typical of small wireless devices. Additionally, these techniques are shown to perform significantly better than a single antenna device in an indoor channel considering realistic values of latency and propagation errors. 相似文献
69.
Merat Hodaie Mirabdullah Seyed Sadjadi Mostafa M. Amini Ezzatollah Najafi Seik Weng Ng 《Journal of Inorganic and Organometallic Polymers and Materials》2016,26(3):500-511
In order systematically investigate the effect of ligand with a large conjugated π-system on the structure and optical properties of tin complex, anthracene-9-carboxylic acid (L1) is selected as a primary ligand, and quinoline-2-carboxylic acid (L2) used as second ligand to incorporate with anthracene-9-carboxylic acid to construct a new tin(IV)-carboxylate coordination complex under thermal gradient condition. Prepared complex was fully characterized based on its 1H and 13C NMR, IR and UV spectra and elemental analysis. The molecular structure of complex was determined by single-crystal X-ray analysis. The nanocrystalline complexes of the prepared complex were successfully obtained at 30, 50 and 60 °C by a facile sonochemical route. The new nanocrystalline complexes were characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analysis. The photoluminescence properties of the nanocrystalline complexes and crystalline bulk complex in the solid-state indicated that the size of the complex particles has a remarkable effect on the optical properties of it. Absorption and emission peaks of the nanocrystalline complexes blue shifted significantly in comparison with those of in the single-crystal form. Application of the prepared complex in fabrication of an organic light-emitting diode has been demonstrated. The current–voltage (I–V) characteristics and the electroluminescence (EL) properties of the complex have been investigated. The EL of the compound exhibits green emission at 552 nm. 相似文献
70.
In a recent paper by Zhang et al. in 2012, a Mach number-invariant scaling was proposed to account for the effect of variation of free-stream Mach number in supersonic turbulent boundary layers. The present work focuses on the effect of variation of wall temperature with strong heating and cooling at the wall. Direct numerical simulation is used to study scaling and turbulence structure of a spatially evolving Mach 2 supersonic boundary layer at a friction Reynolds number of 500. A new scaling law is proposed to account for temperature-dependent fluid-property variations. This universal scaling appears superior to the existing models with the novelty that it applies not only for the mean-velocity profile but also extends to the turbulent transport, production, and dissipation terms in the budget of the turbulent kinetic energy. 相似文献