The wavelet multiresolution interpolation for continuous functions defined on a finite interval is developed in this study by using a simple alternative of transformation matrix. The wavelet multiresolution interpolation Galerkin method that applies this interpolation to represent the unknown function and nonlinear terms independently is proposed to solve the boundary value problems with the mixed Dirichlet-Robin boundary conditions and various nonlinearities, including transcendental ones, in which the discretization process is as simple as that in solving linear problems, and only common two-term connection coefficients are needed. All matrices are independent of unknown node values and lead to high efficiency in the calculation of the residual and Jacobian matrices needed in Newton’s method, which does not require numerical integration in the resulting nonlinear discrete system. The validity of the proposed method is examined through several nonlinear problems with interior or boundary layers. The results demonstrate that the proposed wavelet method shows excellent accuracy and stability against nonuniform grids, and high resolution of localized steep gradients can be achieved by using local refined multiresolution grids. In addition, Newton’s method converges rapidly in solving the nonlinear discrete system created by the proposed wavelet method, including the initial guess far from real solutions.
A quantitative relationship between the 17O substituent chemical shifts (SCS) of γ-alkyl substituents and the torsion angles calculated by the AM1 method is reported. A series of 3-alkyl substituted 5-trichloromethyl-5-hydroxy-4,5-dihydroisoxazoles and 5-trichloromethyl isoxazoles [where 3-alkyl substituents are Me, Et, n-Pr, iso-Bu, BrCH2, iso-Pr, Br2CH and tert-Bu] as model compounds were used. 相似文献
In this Letter, using Backlund transformation and the new variable separation approach, we find a new general solution to the (3 1)-dimensional Burgers equation. The form of the universal formula obtained from many (2 1)-dimensional systems is extended. Abundant localized coherent structures can be found by seclecting corresponding functions appropriately. 相似文献
By means of a Painlevé-Baicklund transformation and a multi-linear separation-of-variable approach, abundant localized coherent excitations of a modified Broer-Kaup system are derived. There appear possible phase shifts for the interactions of the (2+1)-dimensional novel localized structures, which are discussed in this paper. 相似文献
In order to gain insight into the formamide molecule, seven tautomers and twelve transition states are found after being modeled by the density function theory of Becke's three-parameter hybride (B3LYP) type and ab initio Möller–Plesset second-order perturbation (MP2)-type methods. The isomerization phenomena between enol-keto tautomers and transition states via internal rotation or the proton transfer process are surveyed. A localized analysis is also introduced to ascertain the bond character caused by the delocalization of electrons, which will force the formamide tautomers to become planar. The trans effect in the molecule increases molecular stability. 相似文献
The reaction of dichloromaleic anhydride with 1,8-diaminonaphthalene in refluxing toluene or 1,2-dichloroethane produces the new heterocyclic compound 8,9-dichloropyrrolo[1,2-a]perimidin-10-one in low yields. 8,9-Dichloropyrrolo[1,2-a]perimidin-10-one has been isolated by column chromatography and characterized in solution by IR, 1H NMR, and UV/vis spectroscopies. The solid-state structure was unequivocally established by single-crystal X-ray diffraction analysis. 8,9-Dichloropyrrolo[1,2-a]perimidin-10-one crystallizes in the monoclinic space group P21/c, a = 7.475(1)Å, b = 10.650(2)Å, c = 14.468(2)Å, = 94.478(2)°, V = 1148.3(3) Å3, Z = 4, and dcalc = 1.672 Mg/m3; R = 0.0289, Rw = 0.0762 for 1644 reflections with I > 2(I). The nature of the HOMO and LUMO in 8,9-dichloropyrrolo[1,2-a]perimidin-10-one has been determined by extended Hückel molecular orbital calculations, and these data are discussed relative to the cyclic voltammetric data obtained at a platinum electrode. 相似文献
Ab initio molecular orbital theory and density functional theory calculations were performed on the electronic ground states of the open-shell PS2 molecule and its singly charged ions. A comparison of the optimized molecular structures indicates as the stepwise one-electron reduction of the PS2+ ion, to yield PS2 and PS2−, provokes a symmetric elongation of both PS bonds along with a bending of its linear equilibrium geometry. The ionization potential (IP), adiabatic electron affinity (EAad), and atomization energy (AE) of the open-shell PS2 molecule were calculated at different levels of theory. The following values were obtained at the more realistic UMP4SDTQ/6-311+G(3df)//UHF/6-311+G(3df) level of theory: IP=8.32 eV, EAad=3.03 eV and AE=12.40 eV. At the same level of theory, the calculated vertical detachment energy (VDE) of the PS2− anion is 3.22 eV. The donor–acceptor complexes formed in the gas-phase upon interaction of either one or two ammonia molecules with PS2+ were also investigated. The calculated gas-phase binding energies indicate that the formation of the bis-adduct is favored over that of the mono-adduct by a binding energy gain of about 20 kcal/mol. 相似文献