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233.
Nuclear substate parameters have been determined for the 21+ state of 24Mg following the 12C(16O, α) reaction in the vicinity of the Coulomb barrier. Hauser-Feshbach fits describe the data rather poorly and suggest the need for including exit-channel partial-wave interference, particularly around the “quasimolecular” resonant anomaly at 9.3 MeV c.m. Fits employing a Breit-Wigner resonance amplitude plus an incoherent compound nucleus background are most consistent with the resonance being 3? or 5?. 相似文献
234.
Richard P. Metzger JR Oguzhan Cifdaloz Thanate Dhirasakdanon Bruno Welfert 《International Journal of Mathematical Education in Science & Technology》2013,44(6):877-896
This paper describes an interactive modelling, simulation, animation, and real-time control (MoSART) environment for a class of ‘cart-pendulum’ electromechanical systems that may be used to enhance learning within differential equations and linear algebra classes. The environment is useful for conveying fundamental mathematical/systems concepts through computer-aided analysis, design, graphical visualization, and 3D animation. Referred to as Cart-Pendulum Control3D-Lab1, the environment is based on Microsoft Windows/Visual C++/Direct-3D and MATLAB/Simulink2. Pull-down menus provide access to systems/models/control laws, exogenous signals, parameters, animation models and visual indicators, a suite of (easy-to-modify) Simulant diagrams containing models and control laws, MATLAB m-files for detailed analysis and design, and detailed documentation for each of the above. Three blocks enable animation, joystick inputs, and real-time animation within Simulant. Examples are presented to illustrate the utility of the environment as a valuable tool for analysing/visualizing the above class of electromechanical systems and for enhancing mathematics instruction. 相似文献
235.
K. Minamisono P. F. Mantica T. J. Mertzimekis A. D. Davies M. Hass J. Pereira J. S. Pinter W. F. Rogers J. B. Stoker B. E. Tomlin R. R. Weerasiri 《The European physical journal. Special topics》2007,150(1):145-146
The nuclear magnetic moment of the ground state of 57Cu(Iπ = 3/2-, T1/2 = 196.3 ms) has been measured to be |μ(57Cu)| = (2.00 ±0.05) μN using the β-NMR technique. Together with the known magnetic moment of the mirror partner 57Ni, the spin expectation value was extracted as
= -0.78 ± 0.13. Discrepancy between present results and shell model calculations in the full fp shell implies significant
shell breaking at 56Ni with the neutron number N = 28. 相似文献
236.
Richardson G; King JR 《The Quarterly Journal of Mechanics and Applied Mathematics》2007,60(2):161-200
We consider a steady flow driven by pushing a finger of gasinto a highly shear-thinning power-law fluid, with exponentn, in a Hele-Shaw channel. We formulate the problem in termsof the streamfunction , which satisfies the p-Laplacian equation (with ), and investigate travelling wave solutions in the large-n (extreme shear-thinning) limit.We take a Legendre transform of the free-boundary problem for, which reduces it to a linear problem on a fixed domain. The solution to this problem is foundby using matched asymptotic expansions and the resulting shapeof the finger deduced (being, to leading order, a semi-infinitestrip). The nonlinear problem for the streamfunction is alsotreated using matched asymptotic expansion in the physical plane.The finger-width selection problem is briefly discussed in termsof our results. 相似文献
237.
Abstract Humic substances are the major organic constituents of soils and sediments. They also occur in small concentrations in natural surface waters and groundwaters. They form through the breakdown of plant and animal tissues by chemical and biological processes that tend to produce complex chemical structures that are more stable than the original material from which they were derived. One of the more important characteristics of humic substances is their ability to form water-soluble and water-insoluble complexes with metal ions and hydrous oxides and to interact with clay minerals and various organic compounds such as alkanes, fatty acids, and toxic organic substances such as pesticides. 相似文献
238.
Minamisono K Mantica PF Mertzimekis TJ Davies AD Hass M Pereira J Pinter JS Rogers WF Stoker JB Tomlin BE Weerasiri RR 《Physical review letters》2006,96(10):102501
The nuclear magnetic moment of the ground state of (57)Cu(Iota(pi) = 3/2(-), T(1/2) = 196.3 ms) has been measured to be /mu((57)Cu)/ = (2.00 +/- 0.05)mu(N) using the beta-NMR technique. Together with the known magnetic moment of the mirror partner (57)Ni, the spin expectation value was extracted as = -0.078 +/- 0.13. This is the heaviest isospin mirror T = 1/2 pair above the (40)Ca region for which both ground state magnetic moments have been determined. The discrepancy between the present results and shell-model calculations in the full f p shell giving mu((57)Cu) approximately 2.4mu(N) and approximately 0.5 implies significant shell breaking at (56)Ni with the neutron number N = 28. 相似文献
239.
Hassène Gritli Nahla Khraief Safya Belghith 《Communications in Nonlinear Science & Numerical Simulation》2012,17(11):4356-4372
This paper presents a study of the passive dynamic walking of a compass-gait biped robot as it goes down an inclined plane. This biped robot is a two-degrees-of-freedom mechanical system modeled by an impulsive hybrid nonlinear dynamics with unilateral constraints. It is well-known to possess periodic as well as chaotic gaits and to possess only one stable gait for a given set of parameters. The main contribution of this paper is the finding of a window in the parameters space of the compass-gait model where there is multistability. Using constraints of a grazing bifurcation on the basis of a shooting method and the Davidchack–Lai scheme, we show that, depending on initial conditions, new passive walking patterns can be observed besides those already known. Through bifurcation diagrams and Floquet multipliers, we show that a pair of stable and unstable period-three gait patterns is generated through a cyclic-fold bifurcation. We show also that the stable period-three orbit generates a route to chaos. 相似文献