3,215 research outputs found
Chiral Symmetry and N*(1440) -> N pi pi Decay
The N*(1440) -> N pi pi decay is studied by making use of the chiral
reduction formula. This formula suggests a scalar-isoscalar pion-baryon contact
interaction which is absent in the recent study of Hern{\'a}ndez et al. The
contact interaction is introduced into their model, and is found to be
necessary for the simultaneous description of g_{RN pi pi} and the pi-pi and
pi-N invariant mass distributions.Comment: 12 page
Dynamic absorption of carbon dioxide on microporous carbons
Adsorption of carbon dioxide on microporous carbon
Accurate retrieval of structural information from laser-induced photoelectron and high-harmonic spectra by few-cycle laser pulses
By analyzing ``exact'' theoretical results from solving the time-dependent
Schr\"odinger equation of atoms in few-cycle laser pulses, we established the
general conclusion that differential elastic scattering and photo-recombination
cross sections of the target ion with {\em free} electrons can be extracted
accurately from laser-generated high-energy electron momentum spectra and
high-order harmonic spectra, respectively. Since both electron scattering and
photoionization (the inverse of photo-recombination) are the conventional means
for interrogating the structure of atoms and molecules, this result shows that
existing few-cycle infrared lasers can be implemented for ultrafast imaging of
transient molecules with temporal resolution of a few femtoseconds.Comment: 4 pages, 4 figure
Role of the Schizosaccharomyces pombe F-box DNA helicase in processing recombination intermediates.
In an effort to identify novel genes involved in recombination repair, we isolated fission yeast Schizosaccharomyces pombe mutants sensitive to methyl methanesulfonate (MMS) and a synthetic lethal with rad2. A gene that complements such mutations was isolated from the S. pombe genomic library, and subsequent analysis identified it as the fbh1 gene encoding the F-box DNA helicase, which is conserved in mammals but not conserved in Saccharomyces cerevisiae. An fbh1 deletion mutant is moderately sensitive to UV, MMS, and ¿ rays. The rhp51 (RAD51 ortholog) mutation is epistatic to fbh1. fbh1 is essential for viability in stationary-phase cells and in the absence of either Srs2 or Rqh1 DNA helicase. In each case, lethality is suppressed by deletion of the recombination gene rhp57. These results suggested that fbh1 acts downstream of rhp51 and rhp57. Following UV irradiation or entry into the stationary phase, nuclear chromosomal domains of the fbh1¿ mutant shrank, and accumulation of some recombination intermediates was suggested by pulsed-field gel electrophoresis. Focus formation of Fbh1 protein was induced by treatment that damages DNA. Thus, the F-box DNA helicase appears to process toxic recombination intermediates, the formation of which is dependent on the function of Rhp51
Potential for ultrafast dynamic chemical imaging with few-cycle infrared lasers
We studied the photoelectron spectra generated by an intense few-cycle
infrared laser pulse. By focusing on the angular distributions of the back
rescattered high energy photoelectrons, we show that accurate differential
elastic scattering cross sections of the target ion by free electrons can be
extracted. Since the incident direction and the energy of the free electrons
can be easily changed by manipulating the laser's polarization, intensity, and
wavelength, these extracted elastic scattering cross sections, in combination
with more advanced inversion algorithms, may be used to reconstruct the
effective single-scattering potential of the molecule, thus opening up the
possibility of using few-cycle infrared lasers as powerful table-top tools for
imaging chemical and biological transformations, with the desired unprecedented
temporal and spatial resolutions.Comment: 16 pages, 6 figure
Capacity building in Ocean Bathymetry: The Nippon Foundation GEBCO Training Programme at the University of New Hampshire
A successful Capacity Building project in hydrography is underway at the University of New Hampshire. Organised by the General Bathymetric Chart of the Oceans and sponsored by the Nippon Foundation, the programme trains hydrographers and other marine scientists in bathymetric mapping. Participants are formally prepared to produce bathymetric maps when they return to their home countries through a combination of graduate level courses and workshops, practical field training, participation in deep ocean research cruises, working visits to other laboratories and institutions, focused lectures from visiting experts, and the preparation of a bathymetry map of their area from public domain data. Intangible but necessary preparation includes the networking with professionals in bathymetry and related fields within Ocean Mapping, and the building of a cadre of graduates who will form the basis of international bathymetric mapping in the future
Phase Diagram of Lattice-Spin System RbCoBr
We study the lattice-spin model of RbCoBr which is proposed by Shirahata
and Nakamura, by mean field approximation. This model is an Ising spin system
on a distorted triangular lattice. There are two kinds of frustrated variables,
that is, the lattice and spin. We obtain a phase diagram of which phase
boundary is drawn continuously in a whole region. Intermediate phases that
include a partial disordered state appear. The model has the first-order phase
transitions in addition to the second-order phase transitions. We find a
three-sublattice ferrimagnetic state in the phase diagram. The three-sublattice
ferrimagnetic state does not appear when the lattice is not distorted.Comment: 5 pages, 4 figures, jpsj2.cls, to be published in J. Phys. Soc. Jpn.
Vol.75 (2006) No.
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