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71.
An alternative approximation scheme has been used in solving the Schr?dinger equation to the more general case of exponential
screened Coulomb potential, V(r) = −(a/r)[1 + (1 + br)e
−2br
]. The bound state energies of the 1s, 2s and 3s-states, together with the ground state wave function are obtained analytically upto the second perturbation term.
相似文献
72.
The supersymmetric solutions of PT -symmetric and Hermitian/non-Hermitian forms of quantum systems are obtained by solving the Schr?dinger equation for the
Exponential-Cosine Screened Coulomb potential. The Hamiltonian hierarchy inspired variational method is used to obtain the
approximate energy eigenvalues and corresponding wave functions.
相似文献
73.
A wide variety of alkoxymethyltrifluoroborate substrates were prepared via SN2 displacement of potassium bromomethyltrifluoroborate with various alkoxides in excellent yields. These alkoxymethyltrifluoroborates were effectively cross-coupled with several aryl chlorides. This method provides a unique dissonant disconnect that allows greater flexibility in the design of new and improved synthetic pathways. 相似文献
74.
Park YH Ahn HR Canturk B Jeon SI Lee S Kang H Molander GA Ham J 《Organic letters》2008,10(6):1215-1218
Potassium hydroxyaryl- and (hydroxyalkyl)aryltrifluoroborates have been prepared in a simple one-pot process from the corresponding hydroxy-substituted aryl halides in 51-98% yields through an in situ protection of the free hydroxyl group with t-BuLi. Also, we successfully performed a microwave-promoted Suzuki-Miyaura cross-coupling reaction of these substrates with aryl- and alkenyl bromides in the presence of 0.5 mol % of Pd(OAc)2 catalyst without ligands. 相似文献
75.
Violeta?I.?UricanuEmail author Dan?Donescu Andrei?G.?Banu Sever?Serban Marilena?Vasilescu Mihaela?Olteanu Manuela?Dudau 《Journal of Sol-Gel Science and Technology》2005,34(1):23-39
The interplay between the chemical structure of the precursors, internal organization in the end materials and dye retention was investigated for composites (ormosils) doped with rhodamine B. Besides formulations with triethoxysilanes (RTES) only, we synthesized as well organic–inorganic hybrids with addition of titanium isopropoxide (TIP) and maleic anhydride (MA). The organic (R) functionality of RTES was changed from methyl (MeTES), to phenyl (PTES) and octyl (OTES). Atomic force microscopy and electron microscopy, coupled with thermogravimetric analysis prove that hydrophobicity increase stimulates the transition of film structure: from well-defined, compact particles (for MeTES), to a mixture of porous particles and non-granular material (for MeTES/PTES), with extreme results observed for octyl-based composites. For this latter, the apparent homogeneity comes from cluster-like organization, where the primary entities are pseudo—granules produced by hydrophobic interactions of oligomeric siloxanes. Controlling the composition and gelation procedure resulted in doped composites with good optical transparency and rhodamine B fluorescence emission bands at around 580 nm. Dye transport inside the inorganic structure is not facilitated when: (a) the particles have a compact (nonporous) inner structure and (b) the recipe does not contain the TIP/MA combination. For silica-based films, the dye is located in the macropores (between the granules) of the material and could be easy removed by washing with acetone. On the contrary, using TIP/MA changes not only the internal composition of the granular-like material (by creating a microporous titania-rich outer-shell of the particles) but also the affinity of the Rh-B to permeate and reside inside these new structures. 相似文献
76.
The spinless Bethe—Salpeter equation is solved for three attractive static quark-antiquark potentials of the form V(r)=–ar–+br+c, 01, and the effective non-Coulombic power-law potential of the formV(r)=ar
0.1+c to obtain the spin-averaged energy levels in bottomonium (b
) and charmonium (c
) families. The shifted 1/N expansion technique is used. Calculations of the energy eigenvalues are carried out up to third order and parameters of each potential are adjusted to obtain the best agreement with the experimental spin-averaged data (SAD). Flavor-dependent and flavor-independent cases are considered in this work. 相似文献
77.
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80.
The radial part of the effective mass Klein-Gordon equation for the Hulthen potential is solved by making an approximation
to the centrifugal potential. The Nikiforov-Uvarov method is used in the calculations. Energy spectra and the corresponding
eigenfunctions are computed. Results are also given for the case of constant mass. 相似文献