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排序方式: 共有125条查询结果,搜索用时 31 毫秒
21.
G. Palani A. R. Ragavan E. Thandapani 《Journal of Applied Mechanics and Technical Physics》2013,54(6):960-970
An analysis is presented to investigate the influence of viscous dissipation on a free convection flow over a vertical cone with a variable surface heat flux under the action of a transverse magnetic field. The heat transfer characteristics of the free convection flow are investigated numerically. Numerical solutions for transformed governing equations with a variable surface heat flux are obtained. Velocity, temperature, local shear stress, and heat transfer coefficients are calculated for various values of the problem parameters and presented in the graphical form. The effects of the magnetic parameter, the dissipation number, the power-law index, the angle between the cone generatrix and the vertical line, and the Prandtl number on the flow are discussed. For validation of the present numerical results, they are compared with available experimental data and are found to agree well. 相似文献
22.
23.
An analysis is performed to study the free convective flow over a moving vertical porous plate with variable temperature under the influence of magnetic field and thermal radiation. The fluid considered here is a gray, absorbing-emitting radiation, but a nonscattering medium. The dimensionless governing equations are solved using the Laplace transform technique. The velocity, temperature, skin friction and Nusselt number are studied for different parameters like the radiation parameter, Grashof number, Prandtl number, magnetic field parameter, permeability parameter, and time. It is observed that the velocity decreases with increasing radiation parameter. 相似文献
24.
The coupling of propiolic acid with aryl iodides afforded the aryl alkynyl carboxylic acids and aryl alkynes in generally good yields. Aryl alkynyl carboxylic acids were obtained when the reaction was performed in the presence of Pd(PPh3)2Cl2 (2.5 mol %), dppb (5.0 mol %) and DBU (5 equiv) at 50 °C. For the synthesis of the terminal aryl alkynes, the reaction was conducted in the presence of Pd(PPh3)2Cl2 (2.5 mol %), dppb (5.0 mol %), DBU (5.0 equiv), and Cu(acac)2 (10 mol %) at 25 °C for 5 h, and further reacted at 60 °C for 6 h. 相似文献
25.
Palani Sokkan HarikrishnanStephen Michael Rajesh Subbu Perumal 《Tetrahedron letters》2012,53(30):3880-3884
The domino reactions of ethyl 3-oxo-4-(arylsulfonyl)butanoates with aromatic aldehydes in a 2:1 molar ratio in the presence of a catalytic amount of ammonium acetate furnished densely functionalized cyclohexa-1,4-dienes stereoselectively, while the domino reactions of ethyl 3-oxo-4-(arylsulfonyl)butanoates, aromatic aldehydes, and ammonium acetate in a 1:2:2 molar ratio afforded highly functionalized 1,2,5,6-tetrahydropyridines stereoselectively. 相似文献
26.
Free convection over an isothermal vertical plate immersed in a fluid with variable viscosity and thermal conductivity is
studied in this paper. We consider the two-dimensional, laminar and unsteady boundary layer equations. Using the appropriate
variables, the basic governing equations are transformed to non-dimensional governing equations. These equations are then
solved numerically using a very efficient implicit finite difference scheme known as Crank–Nicolson scheme. The fluid considered
in this study is of viscous incompressible fluid of temperature dependent viscosity and thermal conductivity. The effect of
varying viscosity and thermal conductivity on velocity, temperature, shear stress and heat transfer rate are discussed. The
velocity and temperature profiles are compared with previously published works and are found to be in good agreement. 相似文献
27.
Eswaran Chinnaraja Rajendran Arunachalam Renjith S. Pillai Anssi Peuronen Kari Rissanen Palani S. Subramanian 《应用有机金属化学》2020,34(8):e5666
Synthesis of binuclear Cu(II) terminally closed [ 2+2 ]- double-stranded helicate-like macrocycles 1, 1′ , 1″ , 2 , 2′ , 2″ and 2+4- μ4-oxo tetranuclear open frame complexes 3 , 3′ , 3″ , 4 , 4′ , 4″ are established. Adapting one-pot self-assembly technique from simple three components systems: 1,1′-binaphthyl-2,2′-diamine, 4-methyl-2,6-diformyl phenol and cupric salts, the helicate-like [ 2+2 ]- macrocyclic complexes 1–1″, 2–2″ and 2+4- μ4-oxo tetranuclear complexes 3–3″ , 4–4″ were obtained by appropriately altering the reaction condition such as temperature and subcomponent ratio. Density Functional Theory (DFT) calculations were carried out for understanding the structural geometries, intermediates involved in the diverse formation of [ 2+2 ] and 2+4 frameworks. The single crystal X-ray structures obtained for 1′ , 2 and 3 confirms the self-assembly process in line with DFT. This detailed analysis tempted us to derive a plausible mechanism for this long standing challenge in the synthesis of such macrocycles using 1,1′-binaphthyl-2,2′-diamine (BNDA) and aromatic aldehyde. The chiroptical properties of enantiopure complexes and their catalytic applications in asymmetric oxidative coupling of 2-naphthol to chiral 1,1’-Bi-2-naphthol (BINOL) achieved in good yield and ee were discussed. 相似文献
28.
Palani N. S. Kavitha N. S. Venkatesh K. S. Ashok Kumar K. Thirumal V. Pandurangan A. Sekar C. Ilangovan R. 《Journal of Solid State Electrochemistry》2018,22(10):3273-3287
Journal of Solid State Electrochemistry - Graphene sheet/multiwall carbon nanotube (GMC) and its composites with NiO and Ni(OH)2 are synthesized by microwave-assisted technique for the application... 相似文献
29.
A numerical solution of the first-order homogeneous chemical reaction in an unsteady free convective flow past a semi-infinite
vertical plate is studied. The dimensionless governing equations are solved by an efficient, more accurate, unconditionally
stable, and rapidly converging implicit finite-difference scheme. The effect of various parameters, such as the Prandtl number,
Schmidt number, buoyancy ratio parameter, and chemical reaction parameter on flow velocity and temperature is determined.
The velocity profiles are in excellent agreement with available results in the literature. The local and average values of
skin friction and Nusselt and Sherwood numbers are calculated. The effects of the chemical reaction parameters on these values
are discussed for both generative and destructive reactions. Owing to the presence of the first-order chemical reaction, the
velocity is found to increase in the generative reaction and to decrease in the destructive reaction. 相似文献
30.
Journal of Applied Spectroscopy - Amitriptyline hydrochloride (AMH) is a first-generation tricyclic antidepressant drug. Higher doses of AMH may lead to undesirable clinical conditions such as... 相似文献