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Omidi Kashani Behzad Bidarian Behzad 《Journal of Thermal Analysis and Calorimetry》2020,139(4):2499-2508
Journal of Thermal Analysis and Calorimetry - The purpose of the present study is to provide a sub-model for the formation and oxidation of soot based on chemical kinetics for the DC-9 Scania... 相似文献
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In this article developing incompressible viscous flow in an eccentric curved annulus in the presence of gravity is numerically studied using a second order finite difference method based on the projection algorithm to solve the governing equations including the continuity and full Navier–Stokes equations. The equations written in a bipolar–toroidal coordinate system are discretized in a three dimensional staggered grid. The effects of governing non-dimensional parameters including the eccentricity, non-dimensional curvature ratio, Dean number, Froude number, aspect ratio, and the Reynolds number on the flow field in the entrance and fully developed region are investigated. The numerical results indicate that at the small Froude numbers, the flow field distorts from the symmetrical condition due to the larger body force effect and the axial velocity formation mostly takes place at the lower half of the annulus. In addition, at the constant Froude number, by decreasing the curvature radius, the peak axial velocity and its sharp gradient appear on the outer curvature region due to the larger centrifugal forces and by increasing the eccentricity the flow rate intensifies at the wider region and weakens at the narrower region due to the larger flow resistance. Furthermore, the friction factor increases by decreasing the Froude number and increasing the Dean number. 相似文献
24.
Karim Akbari Dilmaghani Behzad Zeynizadeh Mahdi Yari 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1722-1728
The one-pot condensation of aromatic aldehydes, β-dicarbonyl compounds, and urea or thiourea in the presence of H2SO4 supported on silica gel or alumina (80% m/m) in refluxing n-hexane produces 3,4-dihydropyrimidin-2(1H)-ones and their sulfur derivatives in high to excellent yields. 相似文献
25.
Synthesis and characterization of a Ni nanoparticle stabilized on Ionic liquid‐functionalized magnetic Silica nanoparticles for tandem oxidative reaction of primary alcohols 下载免费PDF全文
Rahim Hosseinzadeh‐Khanmiri Yaser Kamel Zahra Keshvari Ahmad Mobaraki Gholam Hossein Shahverdizadeh Esmail Vessally Mirzaagha Babazadeh 《应用有机金属化学》2018,32(9)
In this research, preparation of the magnetic nanoparticle, coating by a silica shell using (3‐aminopropyl) triethoxysilane and synthesis of a novel sulfonic acid‐substituted imidazolium‐based ionic liquid onto the surface of these particles via a multi‐component reaction, is described. The functionalized nanoparticles was loaded by Ni nanoparticles and characterized by means of techniques such as XRD, FTIR, SEM, EDX, TEM, TGA and ICP‐OES. The nanostructures have spherical shapes that ranged in size from 80 to 100 nm. The catalytic activity of these nanoparticles was tested in aerobic oxidation of primary alcohols that showed good performance in the wide range of primary alcohols in water at mild reaction conditions. As a second step of this work, the tandem oxidative synthesis of alkylacrylonitriles and bisindolylmethanes were investigated using primary alcohols under oxidation conditions. This catalyst system can be recovered using external magnet and reused for five consecutive cycles without significantly less of its activity. 相似文献
26.
In this study, the biologically active configurations composed of Thiazolidinedione–Uracil (TU) and Rhodanine–Uracil (RU) have been fully investigated from the energetic and structural points of view, employing B3LYP and M062X functionals in combination with the different basis sets. Dispersion corrections to the interaction energy using M062X–GD3 and double hybrid density functionals (B2PLYP–GD2, B2PLYP–GD3 and mPW2PLYP–GD2) are also taking into account. The basis set superposition error-corrected interaction energy for hydrogen bonded configurations ranges from ??5.27 to ??13.53 and ??5.25 to ??12.93 kcal/mol for TU and RU complexes respectively as calculated at M062X/6–311++G(df,pd) level. The charge transfer process within all of the TU and RU configurations were analyzed using Natural Bond Orbital (NBO) calculations. The nature of the interactions is analyzed with NBO and Atoms in Molecules (AIM) analysis at M062X/6–311++G(df,pd) and energy decomposition analysis at BP86–D3/TZ2P(ZORA)//M062X/6–311++G(df,pd) level of theory. The results confirm that the nature of the interactions is nearly electrostatic, with a contribution of about 51–56% of the total interaction energy. The orbital interactions (ΔEorb) for the considered TU and RU complexes have a contribution of about 24–38% of the total interaction energy. Based on the AIM and NBO results, the interactions were defined as electrostatic H-bonds with partially covalent character. In addition, correlation between interaction energies and vibrational frequency changes was investigated. 相似文献
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Mehdi Rimaz Hossein Mousavi Laya Nikpey Behzad Khalili 《Research on Chemical Intermediates》2017,43(7):3925-3937
29.
Karim Akbari Dilmaghani Behzad Zeynizadeh Hadi Parasajam 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):544-553
Abstract Various 3,4-dihydropyrimidin-2-(1H)-ones (DHPMs) and their sulfur derivatives were efficiently synthesized by a one-pot cyclocondensation reaction of aromatic and aliphatic aldehydes, β-dicarbonyl compounds and urea (or thiourea) in the presence of sulfuric acid immobilized on activated charcoal (133% w/w). The reactions were carried out in refluxing n-hexane-acetonitrile (2.5:0.5 mL) within 5–150 min to give 3,4-dihydropyrimidinones (or thiones) in high to excellent yields (81–97%). 相似文献
30.
A simple method is described for the efficient conversion of trimethylsilyl ethers to their corresponding acetyl and formyl esters in refluxing ethyl acetate or ethyl formate in the presence of TiCl4. 相似文献