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951.
B. Sun Yu. A. Litvinov P. M. Walker K. Beckert P. Beller F. Bosch D. Boutin C. Brandau L. Chen C. Dimopoulou H. Geissel R. Knöbel C. Kozhuharov J. Kurcewicz S. A. Litvinov M. Mazzocco J. Meng C. Nociforo F. Nolden W. R. Plass C. Scheidenberger M. Steck H. Weick M. Winkler 《The European Physical Journal A - Hadrons and Nuclei》2007,31(3):393-394
A new long-lived isomeric state in the near proton dripline nucleus 125Ce has been identified with Schottky mass spectrometry at GSI. The excitation energy E
* = 103(12)keV and the decay time of 193(1)s have been obtained from a single stored fully ionized 125m
Ce58+ ion. The data implies an E3 transition and a 1/2+ assignment for the spin of the isomer. 相似文献
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The paper presents an exact analysis of the dispersion of an immiscible solute in a non-Newtonian fluid (known as an incompressible second-order fluid which shows viscoelastic behaviour) flowing slowly in a parallel plate channel in the presence of a periodic pressure gradient. Using a generalized dispersion model which is valid for all times after the solute injection, the diffusion coefficients K i (τ)(i=1,2,3,…) are obtained as functions of time τ in the case when the initial solute distribution is in the form of a slug of finite extent. The analysis leads to the novel result that K 2(τ) (which is a measure of the longitudinal dispersion coefficient of the solute) has a steady part S in addition to a fluctuating part D 2(τ) due to the pulsatility of the flow. It is found that S decreases with increase in the viscoelastic parameter M for given values of the amplitude λ and frequency ω of the pressure pulsation. On the other hand, it is found that at a fixed instant τ, the amplitude of D 2(τ) increases with increase in M for given values of λ and ω. Further it is shown that at a given instant τ, the amplitude of D 2(τ) decreases with increase in ω for given λ and M and the profile for D 2(τ) becomes progressively flatter with increase in ω. Finally the axial distribution of the average concentration θ m of the solute over the channel cross-section is determined at different instants after the solute injection for several values of M, λ and ω. The present study is likely to have important bearing on the problem of dispersion of tracers in blood flow through arteries. 相似文献
955.
We consider a particular case of the matrix Carleman problem for two pairs of functions in a ring and find a constructive
solution of this problem. In addition, we propose an algorithm for the construction of solutions for two infinite systems
of smooth transition and for a system of two singular equations of special type.
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 49, No. 5, pp. 662–671, May, 1997 相似文献
956.
S. P. Sosnyts'kyi 《Ukrainian Mathematical Journal》1997,49(10):1598-1606
Theorems on equilibrium instability of conservative systems with gyroscopic forces are proved. The theorems obtained are nonlinear
analogs of the Kelvin theorem. The equilibrium instability of the Chaplygin nonholonomic systems is considered.
Institute of Mathematics, Ukrainian Academy of Sciences, Kiev. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 49,
No. 10, pp. 1422–1428, October, 1997. 相似文献
957.
Protein Conformation of a Lattice Model Using Tabu Search 总被引:1,自引:0,他引:1
We apply tabu search techniques to the problem of determining the optimal configuration of a chain of protein sequences on a cubic lattice. The problem under study is difficult to solve because of the large number of possible conformations and enormous amount of computations required. Tabu search is an iterative heuristic procedure which has been shown to be a remarkably effective method for solving combinatorial optimization problems. In this paper, an algorithm is designed for the cubic lattice model using tabu search. The algorithm has been tested on a chain of 27 monomers. Computational results show that our method outperforms previously reported approaches for the same model. 相似文献
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Polycarbonates and copolycarbonates based on BPSi and BPA were easily made using the standard interfacial technique. Molecular weight and NMR data indicate that up to 4 mol % of the BPSi decomposes during polymerization via a base-catalyzed rearrangement of BPSi to arylsiloxanes. Oxygen index studies show an increased flame resistance with increasing BPSi monomer content. DSC measurements show a decrease in glass transition with BPSi monomer concentration while TGA shows an increase in char residue with BPSi monomer content. In addition, TGA indicates no change in either thermal or thermooxidative stability with the relative BPSi/BPA concentrations. Outdoor weathering of BPSi PC and BPA PC films indicates that BPSi PC is ca. 5 times more weathering resistant than BPA PC. This latter result can be attributed to a combination of BPSi PC's lower UV absorptivity, higher water repellency, and lower likelihood for side chain photooxidation. © 1993 John Wiley & Sons, Inc. 相似文献