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141.
142.
T. K. Kar Swarnakamal Misra B. Mukhopadhyay 《Journal of Applied Mathematics and Computing》2006,22(1-2):387-401
This paper deals with the problem of a ratio-dependent prey-predator model with combined harvesting. The existence of steady states and their stability are studied using eigenvalue analysis. Boundedness of the exploited system is examined. We derive conditions for persistence and global stability of the system. The possibility of existence of bionomic equilibria has been considered. The problem of optimal harvest policy is then solved by using Pontryagin’s maximal principle. 相似文献
143.
Efficient and high-power intracavity frequency doubled diode-side-pumped Nd:YAG/KTP continuous wave (CW) green laser 总被引:1,自引:0,他引:1
Highly efficient continuous wave (CW) green beam generation by intracavity frequency doubling of a diode side-pumped Nd:YAG laser using a single pump head based on a copper-coated flow tube in a V-shaped cavity geometry has been demonstrated. A maximum 30.5 W of CW green power was obtained at a total diode pumping power of 260 W corresponding to 11.7% conversion efficiency of diode pump power to CW green power and 4.7% conversion efficiency of electrical power to CW green power. The performance of the laser by considering the pump power induced thermal lensing effect and the M2-parameter at the fundamental wavelength has been analyzed. 相似文献
144.
G. Singh A. Mukhopadhyay P. L. Jain 《Zeitschrift für Physik A Hadrons and Nuclei》1993,345(3):305-309
The techniques of scaled factorial moments and multifractals have been employed to study the dynamical fluctuations of the produced singly charged particles in collisions of84Kr ions at 1.52 A GeV in nuclear emulsion. The power law behaviors are observed in the data. The generalized dimensions are determined by using the methods of intermittency and multifractals. 相似文献
145.
D. Mukhopadhyay 《Physics letters. A》1976,55(6):371-372
The plasma frequency in many-valley semiconductors has been calculated under high field conditions. It is observed that the carrier population in the different valleys can be obtained from a measurement of the plasma frequency under high-field condition. 相似文献
146.
147.
The problem of calculating the non-retarded Van der Waals type of interaction between two spherical voids in an electron gas is presented from a new approach. The formulation is based on an integral equation for the self-induced density oscillations derived from a semi-classical treatment of the density-density response theory for inhomogeneous electron systems. The interaction energy between two identical voids is found to obey d-6 law for large separation d between the voids, the law being determined by the dipolar plasma oscillations alone. 相似文献
148.
We study the full polarization dynamics of two interacting systems of spin and spin I for the Breit-Rabi hamiltonian, the sum of contact hyperfine and Zeeman terms. We obtain the time dependence of the polarizations by solving the eigenvalue problems for the interaction hamiltonian and discuss some applications. 相似文献
149.
Malay Ghosh Gutti Jogesh Babu Nitis Mukhopadhyay 《Probability Theory and Related Fields》1975,33(1):49-54
For a sequence of independent and identically distributed positive random variables, the almost sure convergence of sums of maxima (when suitably normalized) to appropriate constants is proved for both bounded and unbounded random variables. A similar result is also proved for sums of minima of such variables. 相似文献
150.
A. Fonseca K. Hernadi P. Piedigrosso J.-F. Colomer K. Mukhopadhyay R. Doome S. Lazarescu L.P. Biro P. Lambin P.A. Thiry D. Bernaerts J.B. Nagy 《Applied Physics A: Materials Science & Processing》1998,67(1):11-22
The quantities of deposited carbon were measured and the quality of the nanotubes was characterized by means of transmission
electron microscopy and scanning tunneling microscopy. The inner and outer diameters of the nanotubes were also measured and
the diameter distribution histograms were established. The multi-wall straight and coiled nanotubes were found to be quite
regular with an average inner (outer) diameter of 4–7 nm (15–25 nm) and with lengths up to 50 μm. The walls contain concentric
cylindrical graphene sheets separated by the graphitic interlayer distance. The single-wall nanotubes were found as bundles
of hundreds of aligned straight 1-nm-diameter nanotubes with lengths up to 1-μm.
The influence of various parameters such as the method of catalyst preparation, the nature and the pore size of the support,
the nature of the metal, the quantity of catalyst active particles, and the reaction conditions on the nanotubes formation
were studied. The numbers and dimensions of the catalyst active particles dispersed on the support were found to be of importance
in regulating the shape of the produced nanotubes. Following these results, a model of growth mechanism was suggested for
the nanotubes obtained by this method.
Received: 5 January 1998 相似文献