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991.
Wenchang Chu 《Integral Transforms and Special Functions》2017,28(7):505-518
By reformulating four hypergeometric series formulae, we derive 36 Apéry-like series expressions for the Riemann zeta function, including a couple of identities conjectured by Sun [New series for some special values of L-functions. Nanjing Univ J Math. 2015;32(2): 189–218]. 相似文献
992.
993.
Toll convexity is a variation of the so-called interval convexity. A tolled walk between two non-adjacent vertices and in a graph is a walk, in which is adjacent only to the second vertex of and is adjacent only to the second-to-last vertex of . A toll interval between is a set . A set is toll convex, if for all . A toll closure of a set is the union of toll intervals between all pairs of vertices from . The size of a smallest set whose toll closure is the whole vertex set is called a toll number of a graph , . The first part of the paper reinvestigates the characterization of convex sets in the Cartesian product of two graphs. It is proved that the toll number of the Cartesian product of two graphs equals 2. In the second part, the toll number of the lexicographic product of two graphs is studied. It is shown that if is not isomorphic to a complete graph, . We give some necessary and sufficient conditions for . Moreover, if has at least two extreme vertices, a complete characterization is given. Furthermore, graphs with are characterized. Finally, the formula for is given — it is described in terms of the so-called toll-dominating triples or, if is complete, toll-dominating pairs. 相似文献
994.
995.
996.
997.
A Pantokratoras 《Heat and Mass Transfer》2005,41(12):1085-1094
The steady laminar boundary layer flow along a flat plate is studied taking into account the variation of fluid viscosity and fluid Prandtl number with temperature. In the forced convection case the plate moves with constant velocity and its temperature varies in power law with x. In the mixed convection case the plate temperature is constant and the fluid moves upwards due to an external free stream and due to buoyancy forces. The results are obtained with the direct numerical solution of the boundary layer equations. The study concerns the wall heat transfer, the wall shear stress and velocity and temperature profiles across the boundary layer. The results of the present work are different from those existing in the literature, which have been obtained with the assumption of constant Pr number. 相似文献
998.
A new phenomenon of acoustic streaming 总被引:2,自引:0,他引:2
This paper describes a new phenomenon of acoustic streaming which takes place when a Helmholtz resonator is excited by an
inside sound source with resonant frequency, and takes the form of a strong turbulent jet. The flow visualizations, hot wire
and LDV measurements are combined to investigate the process of acoustic streaming. It is found that this kind of acoustic
streaming results from the contribution of Reynolds stress. 相似文献
999.
Rong Sheng 《Acta Mechanica Sinica》1990,6(2):128-132
In this paper, the basic equations of two-phase liquid metal flow in a magnetic field are derived, and specifically, two-phase
liquid metal MHD flow in a rectangular channel is studied, and the expressions of velocity distribution of liquid and gas
phases and the ratioK
0 of the pressure drop in two-phase MHD flow to that in single-phase are derived. Results of calculation show that the ratioK
0 is smaller than unity and decreases with increasing void fraction and Hartmann number because the effective electrical conductivity
in the two-phase case decreases.
The Project is supported by the National Natural Science Foundation of China. 相似文献
1000.
The generalized Poisson distribution is well known to be a compound Poisson distribution with Borel summands. As a generalization we present closed formulas for compound Bartlett and Delaporte distributions with Borel summands and a recursive structure for certain compound shifted Delaporte mixtures with Borel summands. Our models are introduced in an actuarial context as claim number distributions and are derived only with probabilistic arguments and elementary combinatorial identities. In the actuarial context related compound distributions are of importance as models for the total size of insurance claims for which we present simple recursion formulas of Panjer type. 相似文献