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1.
G. P. Berman 《Journal of Applied Mechanics and Technical Physics》1974,15(3):424-426
The article discusses transverse vibrations of finite amplitude in an electron-ion ring. Far from the region of linear resonances, an equation is obtained for slowly varying amplitudes, and the conditions are found for the excitation of instability of the negative pressure type. Near the lower boundary of the region of linear instability, the conditions are found under which nonlinearity breaks down the stability of the vibrations with finite amplitudes.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 3, pp. 170–172, May–June, 1974.The author is indebted to B. V. Chirikov for his evaluation of the results of the work. 相似文献
2.
3.
Friction factors and velocity profiles in turbulent drag reduction can be compared to Newtonian fluid turbulence when the shear viscosity at the wall shear rate is used for the Reynolds number and the local shear viscosity is used for the non-dimensional wall distance. On this basis, an apparent maximum drag reduction asymptote is found which is independent of Reynolds number and type of drag reducing additive. However, no shear viscosity is able to account for the difference between the measured Reynolds stress and the Reynolds stress calculated from the mean velocity profile (the Reynolds stress deficit). If the appropriate local viscosity to use with the velocity fluctuation correlations includes an elongational component, the problem can be resolved. Taking the maximum drag reduction asymptote as a non-Newtonian flow, with this effective viscosity, leads to agreement with the concept of an asymptote only when the solvent viscosity is used in the non-dimensional wall distance. 相似文献
4.
5.
Jamie B. Côté Andrew RoughtonJoanna Nasielski Jeff WilsonJi Chang You Judd M. Berman 《Tetrahedron letters》2011,52(44):5750-5751
The acid mediated cyclization of a protected N-acylhydroxyguanidine into the corresponding 3-amino-1,2,4-oxadiazole and confirmation of its structure by single crystal X-ray crystallography is reported herein. The yield of the cyclization is comparable to literature reports utilizing alternative procedures. Importantly, these new conditions provide complementary chemoselectivity to current synthetic procedures which may be useful for the synthesis of 3-amino-1,2,4-oxadiazoles in general. 相似文献
6.
The gradual covering location problem seeks to establish facilities on a network so as to maximize the total demand covered, allowing partial coverage. We focus on the gradual covering location problem when the demand weights associated with nodes of the network are random variables whose probability distributions are unknown. Using only information on the range of these random variables, this study is aimed at finding the “minmax regret” location that minimizes the worst-case coverage loss. We show that under some conditions, the problem is equivalent to known location problems (e.g. the minmax regret median problem). Polynomial time algorithms are developed for the problem on a general network with linear coverage decay functions. 相似文献
7.
Hossein Abouee-Mehrizi Sahar Babri Oded Berman Hassan Shavandi 《Mathematical Methods of Operations Research》2011,74(2):233-255
In this paper, we consider the problem of making simultaneous decisions on the location, service rate (capacity) and the price
of providing service for facilities on a network. We assume that the demand for service from each node of the network follows
a Poisson process. The demand is assumed to depend on both price and distance. All facilities are assumed to charge the same
price and customers wishing to obtain service choose a facility according to a Multinomial Logit function. Upon arrival to
a facility, customers may join the system after observing the number of people in the queue. Service time at each facility
is assumed to be exponentially distributed. We first present several structural results. Then, we propose an algorithm to
obtain the optimal service rate and an approximate optimal price at each facility. We also develop a heuristic algorithm to
find the locations of the facilities based on the tabu search method. We demonstrate the efficiency of the algorithms numerically. 相似文献
8.
J. Glister G. Ron B.W. Lee R. Gilman A.J. Sarty S. Strauch D.W. Higinbotham E. Piasetzky K. Allada W. Armstrong J. Arrington H. Arenhövel A. Beck F. Benmokhtar B.L. Berman W. Boeglin E. Brash A. Camsonne J. Calarco J.P. Chen S. Choi E. Chudakov L. Coman B. Craver F. Cusanno J. Dumas C. Dutta R. Feuerbach A. Freyberger S. Frullani F. Garibaldi J.-O. Hansen T. Holmstrom C.E. Hyde H. Ibrahim Y. Ilieva C.W. de Jager X. Jiang M.K. Jones Hyekoo Kang A. Kelleher E. Khrosinkova E. Kuchina G. Kumbartzki J.J. LeRose R. Lindgren P. Markowitz S. May-Tal Beck E. McCullough D. Meekins 《Physics letters. [Part B]》2011
9.
Oleg L. Berman Roman Ya. Kezerashvili Yurii E. Lozovik David W. Snoke R. Balili B. Nelsen L. Pfeiffer K. West 《Superlattices and Microstructures》2011
The theoretical and experimental status of the Bose–Einstein Condensation (BEC) of trapped quantum well (QW) polaritons in a microcavity is presented. The results of recent experiments that have shown the possibility to create an in-plane harmonic potential trap for a two-dimensional (2D) exciton polaritons in a cavity are discussed. We report the theory of BEC and of the trapped QW exciton polaritons in a microcavity. In addition, we study the BEC of trapped magnetoexciton polaritons in a graphene layer (GL) embedded in an optical microcavity in high magnetic field. In both cases the polaritons are considered to be in a harmonic potential trap. We compare the theoretical results with the existing experiments and discuss the experimental observation of predicted phenomena. 相似文献
10.
Optimal location with equitable loads 总被引:1,自引:0,他引:1
Oded Berman Zvi Drezner Arie Tamir George O. Wesolowsky 《Annals of Operations Research》2009,167(1):307-325
The problem considered in this paper is to find p locations for p facilities such that the weights attracted to each facility will be as close as possible to one another. We model this problem
as minimizing the maximum among all the total weights attracted to the various facilities. We propose solution procedures
for the problem on a network, and for the special cases of the problem on a tree or on a path. The complexity of the problem
is analyzed, O(n) algorithms and an O(pn
3) dynamic programming algorithm are proposed for the problem on a path respectively for p=2 and p>2 facilities. Heuristic algorithms (two types of a steepest descent approach and tabu search) are proposed for its solution.
Extensive computational results are presented. 相似文献