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61.
Groh DE Mantica PF Stuchbery AE Stolz A Mertzimekis TJ Rogers WF Davies AD Liddick SN Tomlin BE 《Physical review letters》2003,90(20):202502
Spin polarization of 37K nuclei produced via single proton pickup from a 9Be target by a beam of 150 MeV/nucleon 36Ar has been observed. Positive spin polarization with magnitude (8.5+/-0.6)% was deduced near the peak of the 37K momentum distribution. The variation of the spin polarization as a function of outgoing 37K momentum is explained by a classical conservation model, as previously applied to describe the induced spin polarization observed for fragments produced in intermediate-energy heavy-ion reactions, with the condition that the picked-up proton has an average momentum equal to the Fermi momentum and is aligned along the incident beam direction. 相似文献
62.
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
63.
M. D. Schulte S. J. Clarson L. V. Natarajan D. W. Tomlin T. J. Bunning 《Liquid crystals》2013,40(4):467-475
The effects of fluorinated acrylate monomers on the electro-optical and morphological properties of polymer dispersed liquid crystal (PDLC) films are reported. The partial fluorination of host polymer matrices resulted in improved optical properties and better defined morphologies. An enhancement in contrast ratio was observed for fluorinated systems containing trifluoroethyl acrylate (TFEA) and hexafluoroisopropyl acrylate (HFIPA). Conversely, the incorporation of methyl acrylate (MA), a chemically similar non-fluorinated acrylate, resulted in no appreciable change in contrast ratio and an increase in relaxation time. Scanning electron microscopy morphological studies were conducted to understand further the influence of fluorinated monomers in PDLC systems. 相似文献
64.
Du?an M. Stipanovi? Claire J. Tomlin George Leitmann 《Applied Mathematics and Optimization》2012,66(3):455-473
In this paper the problem of accomplishing multiple objectives by a number of agents represented as dynamic systems is considered. Each agent is assumed to have a goal which is to accomplish one or more objectives where each objective is mathematically formulated using an appropriate objective function. Sufficient conditions for accomplishing objectives are derived using particular convergent approximations of minimum and maximum functions depending on the formulation of the goals and objectives. These approximations are differentiable functions and they monotonically converge to the corresponding minimum or maximum function. Finally, an illustrative pursuit-evasion game example with two evaders and two pursuers is provided. 相似文献
65.
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
66.
Advanced biofuels have the potential to supplant significant fractions of conventional liquid fossil fuels. However, the range of potential compounds could be wide depending on selected feedstocks and production processes. Not enough is known about the engine relevant behavior of many of these fuels, particularly when used within complex blends. Simulation tools may help to explore the combustion behavior of such blends but rely on robust chemical mechanisms providing accurate predictions of performance targets over large regions of thermochemical space. Tools such as automatic mechanism generation (AMG) may facilitate the generation of suitable mechanisms. Such tools have been commonly applied for the generation of mechanisms describing the oxidation of non-oxygenated, non-aromatic hydrocarbons, but the emergence of biofuels adds new challenges due to the presence of functional groups containing oxygen. This study investigates the capabilities of the AMG tool Reaction Mechanism Generator for such a task, using diethyl ether (DEE) as a case study. A methodology for the generation of advanced biofuel mechanisms is proposed and the resultant mechanism is evaluated against literature sourced experimental measurements for ignition delay times, jet-stirred reactor species concentrations, and flame speeds, over conditions covering φ = 0.5–2.0, P = 1–100 bar, and T = 298–1850 K. The results suggest that AMG tools are capable of rapidly producing accurate models for advanced biofuel components, although considerable upfront input was required. High-quality fuel specific reaction rates and thermochemistry for oxygenated species were required, as well as a seed mechanism, a thermochemistry library, and an expansion of the reaction family database to include training data for oxygenated compounds. The final DEE mechanism contains 146 species and 4392 reactions and in general, provides more accurate or comparable predictions when compared to literature sourced mechanisms across the investigated target data. The generation of combustion mechanisms for other potential advanced biofuel components could easily capitalize on these database updates reducing the need for future user interventions. 相似文献