Facile one-pot synthesis of gold nanoparticles and their sensing protocol

This communication reports facile one pot synthesis of amoxicillin and sodium salt of amoxicillin stabilized gold nanoparticles (Au-NPs). Primarily the cyclic thioether linkage i.e. the thiozolidine ring of amoxicillin is utilized for sequestering Au(III). Fluorescence quenching of these clusters makes it an efficient protocol for sensing Cu(2+) at nano scale levels.     

考虑感应磁场影响时,伸展表面上的MHD驻点流动及其热传递

考虑感应磁场的影响,研究不可压缩粘性流体在伸展表面上,作稳定磁流体动力学(MHD)的驻点流动.通过相似变换,将非线性的偏微分方程,变换成为常微分方程.用打靶法数值地求解变换后的边界层方程,得到不同的磁场参数和Prandtl数Pr时的数值解.对a/c>1和a/c<1两种情况(其中a和c均为正值),讨论感应磁场参数对表面摩擦因数、局部Nusselt数、速度和温度的影响,绘出变化曲线并给予讨论.     

Palladium catalyzed Heck-Mizoroki and Suzuki-Miyaura coupling reactions (Review)

This article is about the progress of palladium compounds as a catalyst for Heck-Mizoroki and Suzuki-Miyaura coupling reactions. Industrial catalysts with broad applicability need continuous catalyst development process through modification of ligand design, geometry and functionality. Recently catalysts have been synthesized through attachment of the activated palladium complexes on the surface of polymer support, particularly, insoluble in reaction medium. An appropriate mixture of palladium salt and ligand is also used as an important modification in some cases to get better results. We surveyed the important palladium compounds synthesized up to early 2014 for Heck-Mizoroki and Suzuki-Miyaura coupling reactions and summarize their progress in terms of ligand modification and other associated parameters.     

Unusual Structural Features in the Lysozyme Derivative of the Tetrakis(acetato)chloridodiruthenium(II,III) Complex

The reaction between the paddle‐wheel tetrakis(acetato)chloridodiruthenium(II,III) complex, [Ru₂(μ‐O₂CCH₃)₄Cl] and hen egg‐white lysozyme (HEWL) was investigated through ESI‐MS and UV/Vis spectroscopy and the formation of a stable metal–protein adduct was unambiguously demonstrated. Remarkably, the diruthenium core is conserved in the adduct while two of the four acetate ligands are released. The crystal structure of this diruthenium–protein derivative was subsequently solved through X‐ray diffraction analysis to 2.1 Å resolution. The structural data are in agreement with the solution results. It was found that HEWL binds two diruthenium moieties, at Asp101 and Asp119, respectively, with the concomitant release of two acetate ligands from each diruthenium center.     

Graphene-enveloped sulfur in a one pot reaction: a cathode with good coulombic efficiency and high practical sulfur content

Graphene-sulfur composites with sulfur fractions as high as 87 wt% are prepared using a simple one-pot, scalable method. The graphene envelops the sulfur particles, providing a conductive shrink-wrap for electron transport. These materials are efficient cathodes for Li-S batteries, yielding 93% coulombic efficiency over 50 cycles with good capacity.     

Adaptation of homotopy analysis method for the numeric–analytic solution of Chen system

In this paper, a new reliable algorithm based on an adaptation of the standard homotopy analysis method (HAM) is presented, which is the multistage homotopy analysis method (MSHAM). The freedom of choosing the auxiliary linear operator and the auxiliary parameter are still present in the MSHAM. The solutions of the non-chaotic and the chaotic Chen system which is a three-dimensional system of ordinary differential equations with quadratic nonlinearities were obtained by MSHAM. Numerical comparisons between the MSHAM and the classical fourth-order Runge–Kutta (RK4) numerical solutions reveal that the new technique is a promising tool for solving the non-linear chaotic and non-chaotic Chen system.     

Dual solutions in mixed convection boundary layer flow of micropolar fluids

The steady mixed convection boundary layer flow over a vertical surface immersed in an incompressible micropolar fluid is considered in this paper. Employing suitable similarity transformations, the governing partial differential equations are transformed into ordinary differential equations, and the transformed equations are solved numerically by the Keller-box method. Numerical results are obtained for the skin friction coefficient and the local Nusselt number as well as the velocity, angular velocity and temperature profiles. Both cases of assisting and opposing buoyant flows are considered. It is found that dual solutions exist for the assisting flow, besides that usually reported in the literature for the opposing flow. Moreover, in contrast to the classical boundary layer theory, the separation point of the boundary layer is found to be distinct from the point of vanishing skin friction.     

Comparison between the homotopy analysis method and homotopy perturbation method to solve coupled Schrodinger-KdV equation

In this paper, we apply the homotopy analysis method (HAM) and the homotopy perturbation method (HPM) to obtain approximate analytical solutions of the coupled Schrodinger-KdV equation. The results show that HAM is a very efficient method and that HPM is a special case of HAM.     

Solution of Delay Differential Equation by Means of Homotopy Analysis Method

The algorithm of approximate analytical solution for delay differential equations (DDE) is obtained via homotopy analysis method (HAM) and modified homotopy analysis method (MHAM). Various examples of linear, nonlinear and system of initial value problems of DDE are solved and the results obtained show that these algorithms are accurate and efficient for the DDE. The convergence of this algorithm is also proved.     

A new monoclinic structure type for ternary gallide MgCoGa2

The crystal structure of MgCoGa₂ (magnesium cobalt digallide) was solved by direct methods and refined in two space groups as P2₁/c (standard choice) and P2₁/n (non‐standard choice). The refined lattice parameters for the standard choice are a = 5.1505 (2), b = 7.2571 (2), c = 8.0264 (3) Å and β = 125.571 (3)°, and for the non‐standard choice are a = 5.1505 (2), b = 7.2571 (2), c = 6.5464 (2) Å and β = 94.217 (3)°. All parameters for MgCoGa₂ refined to R₁ = 0.027 and wR₂ = 0.042 using 594 reflections. The crystal structure peculiarities of this compound are discussed. Particular attention has been given to relationships with other similar structures, such as YPd₂Si and Fe₃C. Crystallographic analysis, together with linear muffin‐tin orbital electronic structure calculations, reveals the presence of three‐dimensional polyatomic nets with partial covalent bonding between the Ga atoms.