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Formation and transport of oxidized reactive nitrogen, ozone, and secondary organic aerosol in Tokyo
Measurements of the major reactive nitrogen species (NOy)i (NOx, peroxyacyl nitrates, HNO3, and particulate nitrate (NO3-), total reactive nitrogen (NOy), volatile organic compounds, OH and HO2, and organic aerosol were made near the urban center of Tokyo in different seasons of 2003-2004 to study the processes involving oxidized forms of reactive nitrogen and O3. Generally, NOx constituted the dominant fraction of NOy throughout the seasons. The NOx/NOy and HNO3/NOy ratios were lowest and highest, respectively, in summer, owing to the seasonally high OH concentration. The fraction of NOy that remained in the atmosphere after emission (RNOy) decreased with the decrease in the NOx/NOy ratio in summer and fall. It is likely that the median seasonal-diurnal variations Of Ox = O3 + NO2 were controlled by those of the background O3 levels, photochemical O3 formation, and vertical transport. Ox showed large increases during midday under stagnant conditions in mid-August 2004. Their in situ production rates calculated by a box model were too slow to explain the observed increases. The high Ox was likely due to the accumulation of Ox from previous days in the upper part of the boundary layer (BL) followed by transport down to near the surface by mixing after sunrise. Considering the tight correlation between Ox and secondary organic aerosol (SOA), it is likely that SOA also accumulated during the course of sea-land breeze circulation in the BL. Copyright 2008 by the American Geophysical Union
Electric Conductivity of the Zero-gap Semiconducting State in Alpha-(BEDT-TTF)2I3 Salt
The electric conductivity which reveals the zero gap semiconducting (ZGS)
state has been investigated as the function of temperature and life time
in order to understand the ZGS state in quarter-filled
-(BEDT-TTF)I salt with four sites in the unit cell. By treating
as a parameter and making use of the one-loop approximation, it is found
that the conductivity is proportional to and for
and independent of and for . Further the
conductivity being independent of in the ZGS state is examined in terms of
Born approximation for the impurity cattering.Comment: 5 pages, 4 figures, submitted to J. Phys. Soc. Jp
K3-fibered Calabi-Yau threefolds I, the twist map
A construction of Calabi-Yaus as quotients of products of lower-dimensional
spaces in the context of weighted hypersurfaces is discussed, including
desingularisation. The construction leads to Calabi-Yaus which have a fiber
structure, in particular one case has K3 surfaces as fibers. These Calabi-Yaus
are of some interest in connection with Type II -heterotic string dualities in
dimension 4. A section at the end of the paper summarises this for the
non-expert mathematician.Comment: 31 pages LaTeX, 11pt, 2 figures. To appear in International Journal
of Mathematics. On the web at
http://personal-homepages.mis.mpg.de/bhunt/preprints.html , #
Superconductivity in Organic Compounds with Pseudo-Triangular Lattice
We study spin fluctuation (SF) mediated superconductivity (SC) in a
half-filled square lattice Hubbard model with the transfer matrices -t between
nearest neighbor sites and -t' between a half of next nearest neighbor sites
neighboring along only one of the directions, considering application of
this model to organic kappa-(BEDT-TTF)2X compounds. Varying the t'/t value from
0 to 1, one can interpolate between a square and an equilateral triangular
lattice, the latter giving frustration to antiferromagnetically (AF) coupled
spin systems. Within the fluctuation exchange (FLEX) approximation, we
calculate chi(q,omega), Tc and the SC order parameter for various model
parameter values and find that both AF and SC are suppressed as one approaches
the frustration geometry or |(t'/t)-1| \to 0. The SC phase, however, extends
beyond the AF phase boundary fairly close to t'/t=1 for realistic U/t values.
The order parameter is of x2-y2-type for t'/t1.Comment: 4 pages, 5 eps figures, to appear in J. Phys. Soc. Jp
X-ray and UV spectroscopy of Cygnus X-1 = HDE226868
Observations are presented of Cygnus X-1 with the solid-state spectrometer on the Einstein Observatory. The X-ray spectra of two intensity dips viewed near superior conjunction did not exhibit increased photoelectric absorption. Rather the data support a model in which an increase in the electron scattering optical depth modifies both the observed spectrum and the intensity. The characteristic temperature of the intervening material is greater than 5 x 10 to the 7th power K. These measurements were in part simultaneous with observations by IUE. The ultra violet spectrum and intensity remained relatively constant during an X-ray intensity dip
Integrabilities of the Model with Impurities
The hamiltonian with magnetic impurities coupled to the strongly correlated
electron system is constructed from model. And it is diagonalized exactly
by using the Bethe ansatz method. Our boundary matrices depend on the spins of
the electrons. The Kondo problem in this system is discussed in details. The
integral equations are derived with complex rapidities which describe the bound
states in the system. The finite-size corrections for the ground-state energies
are obtained.Comment: 24 pages, Revtex, To be published in J. Phys.
The beta function of the multichannel Kondo model
The beta function of the multichannel Kondo model is calculated exactly in
the limit of large spin N and channel number M=gamma*N, with constant gamma.
There are no corrections in any finite order of 1/N. One zero is found at a
finite coupling strength, showing directly the Non--Fermi liquid behavior of
the model. This renormalization group flow allows to introduce a variational
principle for the entropy, to obtain the low temperature thermodynamics. Such
in particular the low temperature thermodynamics of the non--crossing
approximation to the Kondo model becomes accessible.Comment: 4 page
Correlation induced switching of local spatial charge distribution in two-level system
We present theoretical investigation of spatial charge distribution in the
two-level system with strong Coulomb correlations by means of Heisenberg
equations analysis for localized states total electron filling numbers taking
into account pair correlations of local electron density. It was found that
tunneling current through nanometer scale structure with strongly coupled
localized states causes Coulomb correlations induced spatial redistribution of
localized charges. Conditions for inverse occupation of two-level system in
particular range of applied bias caused by Coulomb correlations have been
revealed. We also discuss possibility of charge manipulation in the proposed
system.Comment: 6 pages, 4 figures Submitted to JETP Letter
Phase Diagram of -(BEDT-TTF)ICl under High Pressure Based on the First-Principles Electronic Structure
We present a theoretical study on the superconductivity of
-(BEDT-TTF)ICl at 14.2 K under a high hydrostatic
pressure recently found, which is the highest among organic superconductors. In
the present work, we study an effective model using the fluctuation-exchange
(FLEX) approximation based on the results of first-principles calculation. In
the obtained phase diagram, the superconductivity with -like symmetry
is realized next to the antiferromagnetic phase, as a result of the
one-dimensional to two-dimensional crossover driven by the pressure.Comment: 4 pages, 3 figures. accepted for publication in J. Phys. Soc. Jpn.
errors correcte
Superconductivity and Pseudogap in Quasi-Two-Dimensional Metals around the Antiferromagnetic Quantum Critical Point
Spin fluctuations (SF) and SF-mediated superconductivity (SC) in
quasi-two-dimensional metals around the antiferrromagnetic (AF) quantum
critical point (QCP) are investigated by using the self-consistent
renormalization theory for SF and the strong coupling theory for SC. We
introduce a parameter y0 as a measure for the distance from the AFQCP which is
approximately proportional to (x-xc), x being the electron (e) or hole (h)
doping concentration to the half-filled band and xc being the value at the
AFQCP. We present phase diagrams in the T-y0 plane including contour maps of
the AF correlation length and AF and SC transition temperatures TN and Tc,
respectively. The Tc curve is dome-shaped with a maximum at around the AFQCP.
The calculated one-electron spectral density shows a pseudogap in the
high-density-of-states region near (pi,0) below around a certain temperature T*
and gives a contour map at the Fermi energy reminiscent of the Fermi arc. These
results are discussed in comparison with e- and h-doped high-Tc cuprates.Comment: 5 pages, 3 figure
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