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21.
H. Fakhri 《International Journal of Theoretical Physics》2008,47(10):2625-2634
The hierarchy of supersymmetric partner Schrödinger equations for the superpotentials Acot?θ and Btanh?y with A and B as half-integer and negative integer numbers are solved. The number of bound states for given trigonometric and hyperbolic potentials are infinite and finite, respectively. In addition to the spectrum-generating corresponding to the standard supersymmetry which is based on shifting potential parameter, there exist three other different methods for generating the spectrum. The first method is based on supersymmetrizing two given models via infinite and finite number of their bound states. This is realized by the ladder operators which shift only quantum numbers. The second and third methods are based on supersymmetrizing any of the models via all bound states corresponding to hierarchy of their partner potentials. They are respectively realized via simultaneous increasing or decreasing of quantum number and the potential parameter, and also, increasing one of them while decreasing the other. Any of the second and third methods leads to introducing two different classes of the algebraic solutions for both models. 相似文献
22.
B.A. Mamedov 《Journal of Quantitative Spectroscopy & Radiative Transfer》2008,109(7):1277-1280
New analytical results are presented performing to cylindrical exponential integral (CEI) functions for integer and noninteger values of parameter n. These integrals are often employed of two-dimensional radiative transfer in an absorbing-emitting medium and determination of the radiative flux in cylindrical media. The simple and efficient algorithm for the calculation of these functions is developed. The series expansion relations established in this work are accurate enough in the whole range of parameters. 相似文献
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25.
正丁醇在N,N-二甲基甲酰胺+水溶液中的体积性质 总被引:3,自引:0,他引:3
测定了298。15K时正丁醇+N,N-二甲诺甲酰胺(DMF)+水三元系的密度求出正丁醇在DMF+水混合溶剂中的表观摩尔体积。观察2到:⑴Φ^0.E~fm与VDMF^E~fm之间存在相似变化关系,其中Φ2^0.E为正丁醇的过量无限稀释表观摩尔体积,VEMF^E为DMF+水二元系中DMF的过量偏摩尔体积,fm为混合溶剂中DMF的摩尔分数。⑵B1~fm与06212^0.E~fm之间存的反向变化关系。B1 相似文献
26.
在295K下,测定了周萘自由基的特殊1H-TRIPLE谱,探讨了选择抽运频率对摄录此类特殊TRIPLE谱成败的影响. 相似文献
27.
The dynamics of asset lifetime under technological change 总被引:2,自引:0,他引:2
The variable lifetime of assets is analyzed in a serial replacement problem. Technological change impacts the maintenance cost and new asset cost. The optimal asset lifetime appears to be constant only when both costs decrease with the same rate. We identify cases when the technological change decreases or increases the optimal lifetime. 相似文献
28.
A unification of some factorization results regarding products of positive-definite matrices, commutators, and products of involutions is presented. This topic was first presented by Sourour for fields with, in the latter two classes, sufficiently many elements in terms of the order of the matrix being factored. The current presentation is valid for matrices over any field with at least four elements, and is independent of the order of the matrix being factored. 相似文献
29.
R. Radha 《Journal of Mathematical Analysis and Applications》2009,354(2):564-574
The images of Hermite and Laguerre-Sobolev spaces under the Hermite and special Hermite semigroups (respectively) are characterized. These are used to characterize the image of Schwartz class of rapidly decreasing functions f on Rn and Cn under these semigroups. The image of the space of tempered distributions is also considered and a Paley-Wiener theorem for the windowed (short-time) Fourier transform is proved. 相似文献
30.
The structured Bessel-type functions of arbitrary even-order were introduced by Everitt and Markett in 1994; these functions satisfy linear ordinary differential equations of the same even-order. The differential equations have analytic coefficients and are defined on the whole complex plane with a regular singularity at the origin and an irregular singularity at the point of infinity. They are all natural extensions of the classical second-order Bessel differential equation. Further these differential equations have real-valued coefficients on the positive real half-line of the plane, and can be written in Lagrange symmetric (formally self-adjoint) form. In the fourth-order case, the Lagrange symmetric differential expression generates self-adjoint unbounded operators in certain Hilbert function spaces. These results are recorded in many of the papers here given as references. It is shown in the original paper of 1994 that in this fourth-order case one solution exists which can be represented in terms of the classical Bessel functions of order 0 and 1. The existence of this solution, further aided by computer programs in Maple, led to the existence of a linearly independent basis of solutions of the differential equation. In this paper a new proof of the existence of this solution base is given, on using the advanced theory of special functions in the complex plane. The methods lead to the development of analytical properties of these solutions, in particular the series expansions of all solutions at the regular singularity at the origin of the complex plane. 相似文献