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排序方式: 共有170条查询结果,搜索用时 31 毫秒
141.
142.
A high‐resolution accurate mass (HR/AM) approach to identification,profiling and characterization of in vitro nefazodone metabolites using a hybrid quadrupole Orbitrap (Q‐Exactive)
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Simon J. Perry Szilárd Nász Mansoor Saeed 《Rapid communications in mass spectrometry : RCM》2015,29(17):1545-1555
143.
In this study we report the preparation of RuO2/Fe3O4@nSiO2@mSiO2 core–shell powder mesoporous catalyst for heterogeneous oxidation of phenol by peroxymonosulfate (PMS) as oxidant. The properties of this supported catalyst were characterized by SEM–EDS (scanning electron microscopy–energy dispersive X-ray spectroscopy), XRD (powder X-ray diffraction), TEM (transmission electron microscopy), and nitrogen adsorption–desorption. It is found that using ruthenium oxide-based catalyst is highly effective in activating PMS for related sulfate radicals. The effects of catalyst loading, phenol concentration, PMS concentration, reaction temperature, and reusability of the as-prepared catalyst on phenol degradation were investigated. In RuO2/Fe3O4@nSiO2@mSiO2 mesoporous catalyst, Oxone (PMS) was effectively activated and 100 % phenol degradation occurred in 40 min. The magnetic RuO2/Fe3O4@nSiO2@mSiO2 catalyst was facility separated from the solution by an external magnetic field. To regenerate the deactivated catalyst and improve its catalytic properties, three different methods involving annealing in air, washing with water, and applying ultrasonics were used. The catalyst was recovered thoroughly by heat treatment. 相似文献
144.
An facile and efficient protocol for the synthesis of 13-aryl-indeno[1,2-b]naphtha[1,2-e]pyran- 12(13H)- ones has been developed that proceeds via the one-pot three-component sequential reaction of an aromatic aldehyde with β-naphthol and 2H-indene-1,3-dione under solvent-free conditions in the presence of a poly(4-vinylpyridinium)hydrogen sulfate (P(4-VPH)HSO4) catalyst. The catalyst can be reused several times, making this procedure facile, practical, and sustainable. The simple experimental procedure, solvent-free reaction conditions, use of an inexpensive catalyst, short react time, and excellent yields are some of the major advantages of this methodology. 相似文献
145.
Seik Mansoor Ali Vasudevan Raghavan Ali S. Rangwala 《Combustion Theory and Modelling》2013,17(4):495-518
A numerical study of laminar diffusion flames established over a condensed fuel surface, inclined at several angular orientations in the range of –90°?θ?+90° with respect to the vertical axis, under atmospheric pressure and normal gravity environment, is presented. Methanol is employed as the fuel. A numerical model, which solves transient gas-phase, two-dimensional governing conservation equations, with a single-step global reaction for methanol–air oxidation and an optically thin radiation sub-model, has been employed in the present investigation. Numerical results have been validated against the experimental data from the present study. Thereafter, the model is used to investigate the influence of angular orientation of fuel surface on its quasi-steady burning characteristics. Results in terms of fuel mass burning rate, flame stand-off distances, temperature field, velocity profiles and oxygen contours have been presented and discussed in detail. It is observed that orientation angles in the range of –45°?θ? –30° (fuel surface facing upwards), yield the maximum mass burning rates. The flame anchoring location near the leading edge of the fuel surface, normal gradient of fuel vapor mass fraction at the surface and oxygen contours have been used to explore this unique behavior. Based on the numerical results, a theoretical correlation to predict the mass burning rate as a function of fuel surface orientation is also proposed. Furthermore, a discussion on the differences in the structure of laminar diffusion flame established over fuel surface as a function of its angular orientation is included. 相似文献
146.
Mansoor H. Alshehri Barry J. Cox James M. Hill 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2013,67(11):1-9
We study analytically the properties of the optical absorption and the spatial weak-light solitons in a quantum dot molecule system with the interdot tunneling coupling (ITC). It is shown that, for the linear case, there exists tunneling induced transparency (TIT) in the context of a weak ITC, while the TIT can be replaced by Autler-Townes splitting in the presence of a strong ITC. For the nonlinear case, it is probable to realize the spatial optical solitons even under weak light intensity. Interestingly, we find that there appears transformation behavior between the bright and dark solitons by properly turning both the ITC strength and the detuning of the probe field. Meanwhile, the transformation condition of the bright and dark solitons is obtained. Additionally it is also found that the amplitude of the solitons first descends and then rises with the increasing of ITC strength. Our results may have potential applications for nonlinear optical experiments and optical telecommunication engineering in solid systems. 相似文献
147.
To-date, all experiments switching perpendicular magnetic anisotropy (PMA) materials with in-plane spin polarization require external B-fields. Here, in two approaches, it is shown that with Rashba-type in-plane spin polarization and PMA, bistable switching is achievable without external B -fields, and at currents on the order of 107 A/cm2, consistent with recent experiments. Utilization of PMA is primarily discussed, demonstrating the potential for two possibilities: (1) in-plane polarization as a ‘natural’ candidate for precessional switching and (2) bistable switching using a tilted anisotropy axis. Both are shown to lead to stable perpendicular switching without an external B-field, even though spin polarization is in-plane. 相似文献
148.
Muhammad Sajid Maria Ishaque Muhammad Imran Niaz Ahmad Niaz Fayyaz Hussain Umbreen Rasheed R. M. Arif Khalil Syed Mansoor Ali Sardar Sikandar Hayat Muhammad Shoaib 《International journal of quantum chemistry》2024,124(1):e27281
The Density Functional Theory (DFT) calculations interpreted the electronic and optical alteration of Ruddlesden–Popper layered perovskite (Sr3Zr2O7) with substitutional doping of Ti-, Hf-, and Ti+Hf- atoms in place of Zr-atoms by generating the oxygen vacancies (Vos) defect. Formation energy and phonon calculations confirmed that the studied composites are dynamically stable, and the lattice parameters of the considered RP perovskite with and without vacancy defects did not change by introducing a small concentration of doped elements. The doped Sr3Zr2O7 composites show band gap tuning in the presence and absence of Vos, which was 3.31 eV in pristine form, and localized states near the Fermi line due to dopant and Vos, which confirmed the quantized conductance in all composites and may be beneficial for overcoming uniformity issues in nonvolatile memory devices. Isosurface charge density calculations also verified this result by depicting the physical mechanism of charge accumulation and depletion in the layers of RP perovskite in the vicinity of defects, resulting in residual conducting filaments guiding its growth and leading it to a low resistance state. The photosensitive response of this layered perovskite also confirmed its use for memory storage applications. The valuable outcomes of this study predicted that Sr3Zr2O7+Ti+Hf is the most stable and, hence, the best composite for nonvolatile RRAM device applications. 相似文献
149.
Dr. Georgios Pantouris Dr. Junming Ho Dr. Dilip Shah Dr. Mansoor Ali Syed Dr. Lin Leng Prof. Vineet Bhandari Prof. Richard Bucala Prof. Victor S. Batista Prof. J. Patrick Loria Prof. Elias J. Lolis 《Angewandte Chemie (International ed. in English)》2018,57(24):7116-7119
Macrophage migration inhibitory factor (MIF) activates CD74, which leads to severe disorders including inflammation, autoimmune diseases and cancer under pathological conditions. Molecular dynamics (MD) simulations up to one microsecond revealed dynamical correlation between a residue located at the opening of one end of the MIF solvent channel, previously thought to be a consequence of homotrimerization, and residues in a distal region responsible for CD74 activation. Experiments verified the allosteric regulatory site and identified a pathway to this site via the MIF β‐strands. The reported findings provide fundamental insights on a dynamic mechanism that controls the MIF‐induced activation of CD74. 相似文献
150.
S.P.N. Sudhan R. Nasir Ahmed H. Kiyani S. Sheik Mansoor 《Journal of Saudi Chemical Society》2018,22(3):269-278
A simple, green and environmentally benign procedure was developed for the one pot synthesis of 3-methyl-1,4-diphenyl-1,4,5,7-tetrahydro-pyrazolo[3,4-d]pyrimidine-6-one/thiones using catalytic amount of phthalimide-N-sulfonic acid (PISA) in 1-butyl-3-methylimidazolium bromide ([Bmim][Br]) ionic liquid via the three-component reaction of 1-phenyl-3-methyl-1H-pyrazole-5(4H)-one, aromatic aldehyde and urea/thiourea. [Bmim][Br] as reaction media offers several advantages including non-toxic, non-corrosive, shorter reaction times, high yield of the products, mild reaction conditions as well as simple experimental and isolation procedures. 相似文献