Journal of Applied Spectroscopy - With the COVID-19 outbreak, many challenges are posed before the scientific world to curb this pandemic. The diagnostic testing, treatment, and vaccine development... 相似文献
A dispersive solid-phase extraction method based on a new sorbent has been performed on plasma and wastewater samples to determine metoprolol by high-performance liquid chromatography–tandem mass spectrometry. In this study, the analyte was adsorbed from the samples onto microcrystalline cellulose as a green and efficient sorbent and then eluted for use in the determination step. In the mass spectrometer, the analyte was detected in the positive mode and selectivity of the analysis was increased by sequential mass analysis through multiple reaction monitoring. All of the effective parameters in the extraction of metoprolol from plasma and wastewater were optimized. Under optimal conditions the method was linear in the ranges of 1–1,000 and 0.1–1,000 ng/ml in plasma and wastewater samples, respectively. The detection limits of the method were 0.30 and 0.03 ng/ml in plasma and wastewater samples, respectively. The data showed that the method provides low detection limit, wide linear range, good precision and high extraction recovery. Finally several plasma and wastewater samples were successfully analyzed using the method. The use of a small amount of a green and inexpensive sorbent and a low volume of plasma without the need for further pretreatment steps are the main advantages of the method. 相似文献
In the present research, magnesium aluminate spinel was prepared as catalyst support using a novel, facile, and efficient mechanochemical method. The Co-promoted catalysts with 20 wt.% of Ni were fabricated using an impregnation route and the samples were analyzed by the X-ray diffraction (XRD), N2 adsorption/desorption (BET), temperature-programmed reduction and desorption (H2-TPR and O2-TPD), and field emission scanning electron microscopy (FESEM) tests. The results confirmed that all samples have a mesoporous structure with a high specific surface area and the presence of cobalt caused complete CH4 oxidation at low temperatures, and no side reactions were observed. The results indicated that the 3%Co-20%Ni/MgAl2O4 catalyst was the optimal sample among the prepared catalysts, owing to the improvement of reduction features and oxygen mobility. The 50 and 90% of methane conversion was obtained at 530 and 600 °C, respectively. Also, the influence of calcination temperature, GHSV, and feed ratio was determined on the catalytic activity. The obtained outcomes revealed that the calcination temperature has a significant effect on the textural properties and catalytic efficiency. The sample calcined at 700 °C showed the weakest performance, which was related to the sintering of particles at high temperatures. The catalytic stability showed that the 3%Co-20%Ni/MgAl2O4 has acceptable stability during 600 min time of reaction.
Molecular Diversity - The preparation, characterization and application of hydroxyapatite silica propyl bis aminoethoxy ethane cuprous complex (HASPBAEECC) as a novel hybrid nano-catalyst for... 相似文献
Journal of Thermal Analysis and Calorimetry - Effect of different chain extenders, silica nanoparticle loading, and using sol–gel method on the thermal properties of polyurethane (PU) hybrid... 相似文献
In the recent decade, the meshless methods have been handled for solving most of PDEs due to easiness of the meshless methods. One of the popular meshless methods is the element-free Galerkin (EFG) method that was first proposed for solving some problems in the solid mechanics. The test and trial functions of the EFG are based on the special basis. Recently, some modifications have been developed to improve the EFG method. One of these improvements is the variational multiscale EFG procedure. In the current article, the shape functions of interpolation moving least squares approximation have been applied to the variational multiscale EFG technique for solving the incompressible magnetohydrodynamics flow. In order to reduce the elapsed CPU time of simulation, we employ a reduced-order model based on the proper orthogonal decomposition technique. The current combination can be referred to as the reduced-order variational multiscale EFG technique. To illustrate the reduction in CPU time used as well as the efficiency of the proposed method, we applied it for the two-dimensional cases. 相似文献
ABSTRACTUsing density functional theory calculations, we investigate the gas sensing performance of B-, N-doped and BN-codoped C60 fullerenes towards NO and NO2 molecules. The calculated adsorption energies and net charge-transfer values indicate that NO and NO2 molecules have a stronger interaction with the BN-codoped fullerenes compared to the B- or N-doped ones. It is also found that the electronic properties of the BN-codoped C60 exhibit a larger sensitivity towards NO and NO2 molecules. An increase in the concentration of doped/co-doped B and N atoms tends to weaken the gas sensing ability of these systems. 相似文献
In the present work, novel 5-((1-benzyl-1,2,3-triazol-4-yl)methoxybenzylidene)-2-(arylamino)thiazol-4-one thiazolone incorporated triazole derivatives have been designed as tyrosinase inhibitors. The compounds were synthesized through click reaction in good yield. Moreover, the antityrosinas activity of the synthesized derivatives was evaluated. In the search for establishing a click copper-catalyzed azide/alkyne cycloaddition (CuAAC) reaction under strict conditions, in terms of a novel air-stable, a recyclable and efficient magnetic catalyst was planned for new triazole derivatives as a well-organized copper iodide supported on the functionalized Fe3O4@SiO2 core-shell (CuI/Fe3O4@SiO2(TMS-EDTA) nanoparticles). The engineered nanocatalyst synthesized for the first time and characterized by different methods, including FT-IR spectroscopy, XRD, FESEM, EDX, TEM, TGA, and BET analysis. The excellent catalytic performance in ethanol with high surface area (351.7 m2g−1) and short reaction time for diverse functional groups (120–200 min), no use of toxic solvents, reusability of the catalyst, and using eco-friendly conditions are the advantageous of this work. Moreover,the nanocatalyst can be used at least five times without any significant decrease in the yield of the reaction. The thiazolidine-triazole derivatives 9a , 9c , 9e , and 9 g showed promising tyrosinase inhibitory activity with IC50 values in the range of 5.90–9.81 μM. The compounds were found to be considerably more potent tyrosinase inhibitors than the reference inhibitor kojic acid (IC50 = 18.36 μM). 相似文献
Research on Chemical Intermediates - In this work, a novel nanorod-structured organic–inorganic hybrid material namely nanorod-[SiO2-Pr-Im-SO3H][TFA] (N-[SPIS][TFA]) has been synthesized, and... 相似文献
Nonlinear Dynamics - A robust fixed-time control framework is presented to stabilize flexible spacecraft’s attitude system with external disturbance, uncertain parameters of inertia, and... 相似文献