排序方式: 共有55条查询结果,搜索用时 15 毫秒
51.
F. M. ALI R. NAZAR N. M. ARIFIN I.POP 《应用数学和力学(英文版)》2014,35(2):155-166
The problem of steady laminar magnetohydrodynamic (MHD) mixed con- vection stagnation-point flow of an incompressible viscous fluid over a vertical stretch- ing sheet is studied. The effect of an externally magnetic field is taken into account. The transformed boundary layer equations are solved numerically by using an implicit finite-difference scheme. Numerical results are obtained for various values of the mixed convection parameter, Hartmann number, and Prandtl number. The effects of an exter- nally magnetic field on the skin friction coefficient, local Nusselt number, velocity, and temperature profiles for both A 〉 1 and A ~ 1, where A is the velocity ratio parameter, are presented graphically and discussed in detail. Both assisting and opposing flows are considered, and it is found that dual solutions exist for the opposing flow. 相似文献
52.
53.
54.
M. Niyaz Khan Zainudin Arifin M. Rapandi Yusoff 《Reaction Kinetics and Catalysis Letters》1999,67(2):253-259
Nucleophilic second-order rate constant (Kn
ms) for the reaction of DL-proline with ionized phenyl salicylate (PS−) shows a nonlinear decrease with the increase in the content of CH3CN in mixed aqueous solvents at ≤50% v/v CH3CN. The values of kn
ms show a mild increase with the increase in the content of CH3CN at >50% v/v CH3CN. The effect of solvent on kn
ms is explained in terms of solvent effect on the pKa of the conjugate acids of leaving group (i.e. phenolate ion) and DL-proline. 相似文献
55.
Ayesha Samreen Muhammad Sudais Ali Muhammad Huzaifa Nasir Ali Bilal Hassan Fazl Ullah Shahid Ali Nor Anisa Arifin 《Chemical record (New York, N.Y.)》2024,24(1):e202300247
The high-temperature solid oxide fuel cells (SOFCs) are the most efficient and green conversion technology for electricity generation from hydrogen-based fuel as compared to conventional thermal power plants. Many efforts have been made to reduce the high operating temperature (>800 °C) to intermediate/low operating temperature (400 °C<T<800 °C) in SOFCs in order to extend their life span, thermal compatibility, cost-effectiveness, and ease of fabrication. However, the major challenges in developing cathode materials for low/intermediate temperature SOFCs include structural stability, catalytic activity for oxygen adsorption and reduction, and tolerance against contaminants such as chromium, boron, and sulfur. This research aims to provide an updated review of the perovskite-based state-of-the-art cathode materials LaSrMnO3 (LSM) and LaSrCOFeO3 (LSCF), as well as the recent trending Ruddlesden-Popper phase (RP) and double perovskite-structured materials SOFCs technology. Our review highlights various strategies such as surface modification, codoping, infiltration/impregnation, and composites with fluorite phases to address the challenges related to LSM/LSCF-based electrode materials and improve their electrocatalytic activity. Moreover, this study also offers insight into the electrochemical performance of the double perovskite oxides and Ruddlesden-Popper phase materials as cathodes for SOFCs. 相似文献