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71.
Asadollah Zarif Farhad Amarloo Faeze Pourazimi Najmeh Kaftani Zahra Rostamabadi Ebrahim 《Journal of fluorescence》2022,32(5):1639-1650
Journal of Fluorescence - Malachite green (MG) is a dye that has been presented to use as photosensitizers for photodynamic therapy (PDT). Nonlinear absorption coefficient (β) and nonlinear... 相似文献
72.
An efficient heterogeneous Pd catalytic system has been developed, based on immobilization of Pd nanoparticles (PNPs) on a silica-bonded N-propylpiperazine (SBNPP) substrate. The SBNPP substrate effectively stabilizes the PNPs and improves their stability against aggregation. The catalytic activity of this catalyst was investigated in the cyanation of aryl halides with K4[Fe(CN)6 ] as the cyanide source. The catalyst could be recycled several times without appreciable loss of catalytic activity. 相似文献
73.
Robert D. Lotz Brian E. Thompson Christopher A. Konings Farhad Davoudzadeh 《国际流体数值方法杂志》1997,24(4):355-373
Numerical uncertainties are quantified for calculations of transonic flow around a divergent trailing edge (DTE) supercritical aerofoil. The Reynolds-averaged Navier–Stokes equations are solved using a linearized block implicit solution procedure and mixing-length turbulence model. This procedure has reproduced measurements around supercritical aerofoils with blunt trailing edges that have shock, boundary layer and separated regions. The present effort quantifies numerical uncertainty in these calculations using grid convergence indices which are calculated from aerodynamic coefficients, shock location, dimensions of the recirculating region in the wake of the blunt trailing edge and distributions of surface pressure coefficients. The grid convergence index is almost uniform around the aerofoil, except in the shock region and at the point where turbulence transition was fixed. The grid convergence index indicates good convergence for lift but only fair convergence for moment and drag and also confirms that drag calculations are more sensitive to numerical error. © 1997 by John Wiley and Sons, Ltd. 相似文献
74.
Acta Mathematica Sinica, English Series - In this paper we are concerned with absolute, relative and Tate Tor modules. In the first part of the paper we generalize a result of Avramov and... 相似文献
75.
Mohammad Fallahian Behzad Pourabbas Mehdi Sharif Kamran Froutani Mehrnoosh Mahmoodian Mahdi Mohammadizadeh 《Polymer Science Series B》2017,59(3):308-319
In this study polypyrrole (PPy) nanoparticles were deposited as a thin film on the modified surface of polyethyleneterephthalate (PET) by in situ chemical polymerization in the presence of sodium dodecylsulfate (SDS), sodium dodecylbenzenesulfonate (DBSNa) and mixture of them as the surfactant. The surface of PET was modified by KOH before deposition and was investigated for conductivity and adhesion of PPy nanoparticles to PET. Resulting conductive flexible films were characterized by UV–Vis spectroscopy, fieldemission scanning electron microscopy, contact angle measurements and four-point-probe technique for conductivity. Direct morphological observation (FESEM) and electrical measurements indicated that the morphology, conductivity and the nature of deposited PPy films depend on surfactant, surface modification of PET and monomer concentration. In optimized process condition, uniform conductive films of PPy were obtained with good adhesion to PET. 相似文献
76.
Tahereh Ghauri Koodehi Farhad Shirini Omid Goli-Jolodar 《Journal of the Iranian Chemical Society》2017,14(2):443-456
In this work, 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2]·2Cl), as a novel Brönsted acidic ionic catalyst is synthesized and characterized using a series of techniques including FT-IR, TGA, DTA, SEM, pH analysis and Hammett acidity function. This substance can significantly catalyze the N-Boc protection of amines without solvent interference at room temperature. The advantages of this manner are chemoselectivity, short reaction times, suitable yields, excellent yields of the products, without solvent interference and ease of preparation as well as reusability of the catalyst. 相似文献
77.
BiVO4-NPs can be used as an efficient and reusable nano-catalyst for the promotion of the synthesis of biscoumarins, bis(indolyl)methanes and 3,4-dihydropyrimidin-2(1H)-ones (thiones) derivatives. The structures of the products were characterized by IR, 1H NMR and 13C NMR spectroscopy and comparison with the authentic samples. Easy work-up procedure, excellent yields, short reaction times and reusability of the catalyst are some advantages of this work. In addition, in this article and for the first time, the preparation of 3,4-dihydropyrimidin-2(1H)-ones and -thiones from the protected derivatives of aldehydes including oximes, semicarbazones and 1,1-diacetates is reported. 相似文献
78.
A spectral element method using the modal basis and its application in solving second‐order nonlinear partial differential equations 下载免费PDF全文
We present a high‐order spectral element method (SEM) using modal (or hierarchical) basis for modeling of some nonlinear second‐order partial differential equations in two‐dimensional spatial space. The discretization is based on the conforming spectral element technique in space and the semi‐implicit or the explicit finite difference formula in time. Unlike the nodal SEM, which is based on the Lagrange polynomials associated with the Gauss–Lobatto–Legendre or Chebyshev quadrature nodes, the Lobatto polynomials are used in this paper as modal basis. Using modal bases due to their orthogonal properties enables us to exactly obtain the elemental matrices provided that the element‐wise mapping has the constant Jacobian. The difficulty of implementation of modal approximations for nonlinear problems is treated in this paper by expanding the nonlinear terms in the weak form of differential equations in terms of the Lobatto polynomials on each element using the fast Fourier transform (FFT). Utilization of the Fourier interpolation on equidistant points in the FFT algorithm and the enough polynomial order of approximation of the nonlinear terms can lead to minimize the aliasing error. Also, this approach leads to finding numerical solution of a nonlinear differential equation through solving a system of linear algebraic equations. Numerical results for some famous nonlinear equations illustrate efficiency, stability and convergence properties of the approximation scheme, which is exponential in space and up to third‐order in time. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
79.
Nonlinear kernel methods have been widely used to deal with nonlinear problems in latent variable methods. However, in the presence of structured noise, these methods have reduced efficacy. We have previously introduced constrained latent variable methods that make use of any available additional knowledge about the structured noise. These methods improve performance by introducing additional constraints into the algorithm. In this paper, we build upon our previous work and introduce hard‐constrained and soft‐constrained nonlinear partial least squares methods using nonlinear kernels. The addition of nonlinear kernels reduces the effects of structured noise in nonlinear spaces and improves the regression performance between the input and response variables. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
80.
Farhad Haghjoo Nick Barnes Robin Pritchard 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(7):o219-o221
In the crystal structure of the title compound, 2C22H24P+·I82−, the I82− anion is located on a crystallographic inversion centre and consists of two tri‐iodide anions linked by di‐iodine at angles of 89.92 (4)° to form a planar `Z'‐shaped dianion. The octaiodides are linked via long‐range interactions [3.877 (11) Å] into infinite polyiodide ribbons. This is the first example of a structure containing an [(o‐tolyl)3PMe]+ cation, and the CMe—P—C—CMe torsion angles of −54.0 (11), −51.3 (11) and −48.2 (11)° indicate that the configuration is exo3. 相似文献