3,580 research outputs found
Melting of genomic DNA: predictive modeling by nonlinear lattice dynamics
The melting behavior of long, heterogeneous DNA chains is examined within the
framework of the nonlinear lattice dynamics based Peyrard-Bishop-Dauxois (PBD)
model. Data for the pBR322 plasmid and the complete T7 phage have been used to
obtain model fits and determine parameter dependence on salt content. Melting
curves predicted for the complete fd phage and the Y1 and Y2 fragments of the
X174 phage without any adjustable parameters are in good agreement with
experiment. The calculated probabilities for single base-pair opening are
consistent with values obtained from imino proton exchange experiments.Comment: 5 pages, 4 figures, to appear in Phys. Rev.
Required precision of mass and half-life measurements for r-process nuclei planned at future RI-beam facilities
In order to understand the r-process nucleosynthesis, we suggest precision
required for mass and beta-decay half-life measurements planned at future
RI-beam facilities. To satisfy a simple requirement that we put on nuclear
model predictions, it is concluded that the detectors for the mass measurements
must have a precision of 1sigma ~< 250 keV, and that the detectors for the
half-life measurements demand a precision of 1sigma ~< 0.15 ms. Both the above
precisions are required at the neutron richness of A/Z = 3.0 at the N=82 shell
closure and A/Z = 2.9 at the N=50 shell closure. For the doubly magic nuclide
78Ni, a precision of 1sigma ~< 300 keV and 1sigma ~< 5 ms are required,
respectively, for mass and half-life measurements. This analysis aims to
provide a first rough guide for ongoing detector developments.Comment: 8 pages, 2 figures. in Proceedings of Int. conf. The Future
Astronuclear Physics, From microscopic puzzles to macroscopic nightmares,
Eds. H.M.J. Boffin et al., EAS Publication Series, EDP Sciences, in press
(2004
Thermal Phase Transitions and Gapless Quark Spectra in Quark Matter at High Density
Thermal color superconducting phase transitions in three-flavor quark matter
at high baryon density are investigated in the Ginzburg-Landau (GL) approach.
We constructed the GL potential near the boundary with a normal phase by taking
into account nonzero quark masses, electric charge neutrality, and color charge
neutrality. We found that the density of states averaged over paired quarks
plays a crucial role in determining the phases near the boundary. By performing
a weak coupling calculation of the parameters characterizing the GL potential
terms of second order in the pairing gap, we show that three successive
second-order phase transitions take place as the temperature increases: a
modified color-flavor locked phase (ud, ds, and us pairings) -> a ``dSC'' phase
(ud and ds pairings) -> an isoscalar pairing phase (ud pairing) -> a normal
phase (no pairing). The Meissner masses of the gluons and the number of gapless
quark modes are also studied analytically in each of these phases.Comment: 15 pages, 6 figure
Recommended from our members
Tokyo University and the War
Tachibana Takashi analyzes the impact of World War II on Tokyo University and Tokyo University\u27s impact on the war: attacks from outside, faculty politics and purges, institutional expansion, the sacrifice of liberal arts students to the war machine, and heroic dissenting professors who tried in vain to bring the war to an early end.
Translated and edited by Richard H. Minearhttps://scholarworks.umass.edu/history_oapubs/1000/thumbnail.jp
Melting Pattern of Diquark Condensates in Quark Matter
Thermal color superconducting phase transitions in high density three-flavor
quark matter are investigated in the Ginzburg-Landau approach. Effects of
nonzero strange quark mass, electric and color charge neutrality, and direct
instantons are considered. Weak coupling calculations show that an interplay
between the mass and electric neutrality effects near the critical temperature
gives rise to three successive second-order phase transitions as the
temperature increases: a modified color-flavor locked (mCFL) phase (ud, ds, and
us pairings) -> a ``dSC'' phase (ud and ds pairings) -> an isoscalar pairing
phase (ud pairing) -> a normal phase (no pairing). The dSC phase is novel in
the sense that while all eight gluons are massive as in the mCFL phase, three
out of nine quark quasiparticles are gapless.Comment: minor changes in the text, fig.2 modifie
Beiträge zur Kenntnis der Psoriasis syphilitica
Verfasser machte klinische und histologische Untersuchungen über 6 Fälle von Psoriasis luetica und kam zum folgenden Schluss. Psoriasis luetica beträgt 2,7% der rezenten Syphilisfälle von sekundärem Stadium. Sie kommt von 3 Monaten bis 5 Jahre nach der Ansteckung zum Vorschein, bevorzugt Handteller und Fuszsohle, wo die Hornschicht der Epidermis phisiologisch gut entwickelt und am häufigsten einer mechanischen Reizung ausgesetzt ist, und wird sehr selten an Hand-und Fussrücken beobachtet. Die Krankheit kommt häufiger bei Mannern als bei Frauen vor und wird am meisten im 20.-40. Lj. angetroffen. Histologisch findet man Parakeratose, Wucherung oder Atrophie des Stratum granulosum und Akanthose. Gefässkapillaren, besonders in der oberen Kutisschicht, sind stark dilatiert; Zellinfiltration ist in der Papillar-und Subpapillarschicht deutlich zu erkennen. Infiltrierte Zellarten sind hauptsächlich Lymphozyten, Leucocyten, Plasmazellen, und Bindegewebszellen auch vermehrt. In Stachel-und Papillarschicht findet sich leichte Ödembildung.
Psoriasis luetica gehort im allgemeinen zur SpÖt- oder Recidivform der Lues secundaria und reagiert meistens gut auf zutreffende antiluische Kur; in einem Fall erwies sie sich einer kombinierten Arsen-Bismutbehandlung gegeneüber als sehr hartnäckig
Bonding in doped gallium nanoclusters: Insights from regional DFT
The molecular nature (Ga2)n of gallium makes this an interesting metal to investigate for the development of novel nano-materials. However, establishment of a targeted approach to manipulating the properties of gallium clusters requires a detailed understanding of how doping affects the bonding in these species. In this study, the bonding of gallium nanoclusters has been investigated using electron deformation densities and Regional Density Functional Theory (RDFT). Bonding throughout Ga12X clusters is generally intermediate between covalent and metallic. However, the presence of Ga2 subunits is clearly identified in clusters with endohedral dopants (Ga12X, X = Al, Si, P, Ga, Ge, As). Although there is evidence of Ga2 subunits in exohedral doped clusters, localised bonding to the dopant generally leads to significant disruption to the cluster framework. Maps of electronic chemical potential provide understanding for the observed differences in regioselectivity for hydrogen adsorption
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