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排序方式: 共有135条查询结果,搜索用时 968 毫秒
101.
Bikash Sahoo 《Communications in Nonlinear Science & Numerical Simulation》2009,14(3):811-826
The laminar flow and heat transfer of an incompressible, third grade, electrically conducting fluid impinging normal to a plane in the presence of a uniform magnetic field is investigated. The heat transfer analysis has been carried out for two heating processes, namely, (i) with prescribed surface temperature (PST-case) and (ii) prescribed surface heat flux (PHF-case). By means of the similarity transformation, the governing non-linear partial differential equations are reduced to a system of non-linear ordinary differential equations and are solved by a second-order numerical technique. Effects of various non-Newtonian fluid parameters, magnetic parameter, Prandtl number on the velocity and temperature fields have been investigated in detail and shown graphically. It is found that the velocity gradient at the wall decreases as the third grade fluid parameter increases. 相似文献
102.
103.
It is demonstrated that gold (Au) nanoparticles self-assembled on a sol-gel derived three-dimensional silicate network efficiently catalyze the oxidation of NADH in the absence of any electron transfer mediators with a decrease in overpotential of 780 mV in neutral solution. 相似文献
104.
l-N-Formyl tryptophan methyl ester (3) underwent a Bischler-Napieralski reaction with POCl3 at room temperature or under microwave irradiation, resulting in the unusual formation of β-carboline dimers 5 and 6. Most importantly, acetylation using Ac2O of each of the dimers 5 and 6 separately afforded 1-[3′-carbomethoxy-β-carbolinyl]-3-carbomethoxy-9-acetyl-β-carboline (7) as the only product, the structure of which was confirmed by X-ray crystallography studies. 相似文献
105.
Fluorinated Photodynamic Therapy Device Tips and their Resistance to Fouling for In Vivo Sensitizer Release
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Ashwini A. Ghogare Joann M. Miller Bikash Mondal Alan M. Lyons Keith A. Cengel Theresa M. Busch Alexander Greer 《Photochemistry and photobiology》2016,92(1):166-172
We describe progress on a one‐step photodynamic therapy (PDT) technique that is simple: device tip delivery of sensitizer, oxygen and light simultaneously. Control is essential for their delivery to target sites to generate singlet oxygen. One potential problem is the silica device tip may suffer from biomaterial fouling and the pace of sensitizer photorelease is slowed. Here, we have used biomaterial (e.g. proteins, cells, etc.) from SQ20B head and neck tumors and whole blood for an assessment of fouling of the silica tips by adsorption. It was shown that by exchanging the native silica tip for a fluorinated tip, a better nonstick property led to an increased sensitizer output by ~10%. The fluorinated tip gave a sigmoidal photorelease where singlet oxygen is stabilized to physical quenching, whereas the native silica tip with unprotected SiO–H groups gave a slower (pseudolinear) photorelease. A further benefit from fluorinated silica is that 15% less biomaterial adheres to its surface compared to native silica based on a bicinchoninic acid assay (BCA) and X‐ray photoelectron spectroscopy (XPS) measurements. We discuss how the fluorination of the device tip increases biofouling resistance and can contribute to a new pointsource PDT tool. 相似文献
106.
Baishya B Reddy GN Prabhu UR Row TN Suryaprakash N 《The journal of physical chemistry. A》2008,112(42):10526-10532
The proton NMR spectra of fluorine-substituted benzamides are very complex (Figure 1) due to severe overlap of (1)H resonances from the two aromatic rings, in addition to several short and long-range scalar couplings experienced by each proton. With no detectable scalar couplings between the inter-ring spins, the (1)H NMR spectra can be construed as an overlap of spectra from two independent phenyl rings. In the present study we demonstrate that it is possible to separate the individual spectrum for each aromatic ring by spin system filtering employing the multiple-quantum-single-quantum correlation methodology. Furthermore, the two spin states of fluorine are utilized to simplify the spectrum corresponding to each phenyl ring by the spin-state selection. The demonstrated technique reduces spectral complexity by a factor of 4, in addition to permitting the determination of long-range couplings of less than 0.2 Hz and the relative signs of heteronuclear couplings. The technique also aids the judicious choice of the spin-selective double-quantum-single-quantum J-resolved experiment to determine the long-range homonuclear couplings of smaller magnitudes. 相似文献
107.
We study an anisotropic Bianchi-I universe in the presence of a phantom field and a cosmological constant. Cosmological solutions
are obtained when the kinetic energy of the phantom field is of the order of anisotropy and dominates over the potential energy
of the field. The anisotropy of the universe decreases and the universe transits to an isotropic flat FRW universe accommodating
the present acceleration. A class of new cosmological solutions is obtained for an anisotropic universe in case an initial
anisotropy exists which is bigger than the value determined by the parameter of the kinetic part of the field. Later, an autonomous
system of equations for an axially symmetric Bianchi-I universe with phantom field in an exponential potential is studied.
We discuss the stability of the cosmological solutions.
相似文献
108.
109.
Naba Kr Mandal Bhargab Guhathakurta Pritha Basu Ankur Bikash Pradhan Chandra Shekhar Purohit Shubhamoy Chowdhury 《Journal of Coordination Chemistry》2019,72(22-24):3625-3644
AbstractA novel red copper(II) compound, bis(μ-bromo)bis(2-(benzothiazol-2-yl-hydrazono)-1,2-diphenyl-ethanone)-dicopper(II) (1), has been fostered by equimolar reaction of a Schiff-base ligand, 2-(benzothiazol-2-yl-hydrazono)-1,2-diphenyl-ethanone (LH), with copper(II) bromide in satisfactory yield. 1 has thoroughly been characterized by C, H and N elemental analyses, FT-IR and UV-vis (both in solid state and in solution) spectroscopies, and room-temperature magnetic susceptibility and conductivity measurements. Dimeric 1 bears symmetric rare bromo-bridges in its crystal structure. 1 retains its solid-state identity even in a protic solvent like methanol. 1 in methanol displays two-step one-electron redox response. Theoretical calculations based on DFT were executed to probe the electronic structure of 1 and to augment its color. DNA- and RNA-binding aspects of both LH and 1 have been explored. Thermodynamic binding parameters have been determined. LH is a major-groove binder to DNA, while 1 manifests itself as a minor-groove binder. This binding has been corroborated through molecular docking. Nucleic acid binding aspect of such type of rare bromo-bridged red copper(II) dimer is unprecedented. 相似文献
110.
Bikash Kumar Shaw Celia Castillo-Blas Michael F. Thorne María Laura Ríos Gmez Tom Forrest Maria Diaz Lopez Philip A. Chater Lauren N. McHugh David A. Keen Thomas D. Bennett 《Chemical science》2022,13(7):2033
Four novel dicyanamide-containing hybrid organic–inorganic ABX3 structures are reported, and the thermal behaviour of a series of nine perovskite and non-perovskite [AB(N(CN)2)3] (A = (C3H7)4N, (C4H9)4N, (C5H11)4N; B = Co, Fe, Mn) is analyzed. Structure–property relationships are investigated by varying both A-site organic and B-site transition metal cations. In particular, increasing the size of the A-site cation from (C3H7)4N → (C4H9)4N → (C5H11)4N was observed to result in a decrease in Tm through an increase in ΔSf. Consistent trends in Tm with metal replacement are observed with each A-site cation, with Co < Fe < Mn. The majority of the melts formed were found to recrystallise partially upon cooling, though glasses could be formed through a small degree of organic linker decomposition. Total scattering methods are used to provide a greater understanding of the melting mechanism.Increasing the size of the A-site cation from (C3H7)4N → (C4H9)4N → (C5H11)4N in hybrid organic–inorganic ABX3 structures was observed to result in a decrease in Tm, through an increase in ΔSf. 相似文献