15,465 research outputs found
Growth, transport, and magnetic properties of Pr0.67Ca0.33MnO3 thin films
We have grown Pr0.67Ca0.33MnO3 thin films on LaAlO3 using pulsed laser deposition. Below 50 K, a field induced insulator-metal transition results in changes in resistivity of at least 6 orders of magnitude. The field induced conducting state is metastable at low temperature. The temperature dependence of the resistivity exhibits considerable hysteresis in a field of 40 kOe but becomes reversible in a field of 80 kOe
Vitamin or antioxidant intake (or serum level) and risk of cervical neoplasm: a meta‐analysis
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86903/1/BJO_3032_sm_TableS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/86903/2/j.1471-0528.2011.03032.x.pd
Stabilization of a Fabry-Perot interferometer using a suspension-point interferometer
A suspension-point interferometer (SPI) is an auxiliary interferometer for
active vibration isolation, implemented at the suspension points of the mirrors
of an interferometric gravitational wave detector. We constructed a prototype
Fabry-Perot interferometer equipped with an SPI and observed vibration
isolation in both the spectrum and transfer function. The noise spectrum of the
main interferometer was reduced by 40 dB below 1 Hz. Transfer function
measurements showed that the SPI also produced good vibration suppression above
1 Hz. These results indicate that SPI can improve both the sensitivity and the
stability of the interferometer.Comment: 14 pages, 8 figures; added discussion; to be published in Physics
Letters
Production and optical properties of liquid scintillator for the JSNS experiment
The JSNS (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron
Source) experiment will search for neutrino oscillations over a 24 m short
baseline at J-PARC. The JSNS inner detector will be filled with 17 tons
of gadolinium-loaded liquid scintillator (LS) with an additional 31 tons of
unloaded LS in the intermediate -catcher and outer veto volumes.
JSNS has chosen Linear Alkyl Benzene (LAB) as an organic solvent because
of its chemical properties. The unloaded LS was produced at a refurbished
facility, originally used for scintillator production by the RENO experiment.
JSNS plans to use ISO tanks for the storage and transportation of the LS.
In this paper, we describe the LS production, and present measurements of its
optical properties and long term stability. Our measurements show that storing
the LS in ISO tanks does not result in degradation of its optical properties.Comment: 7 pages, 4 figures
EM Decay of X(3872) as the charmonium
The recently BaBar results raise the possibility that X(3872) has negative
parity. This makes people reconsider assigning X(3872) to the state. In this paper we give a general form of the wave function of
mesons. By solving the instantaneous Bethe-Salpeter equation, we get
the mass spectrum and corresponding wave functions. We calculate
electromagnetic decay widths of the first state which we assume to be
the X(3872) particle. The results are keV, eV and keV. The ratio of branch fractions
of the second and first channel is about 0.002, which is inconsistent with the
experimental value . So X(3872) is unlikely to be a
charmonium state. In addition, we obtain a relatively large decay width for
channel which is keV.Comment: Revised versio
Population Growth and Competition Models with Decay and Competition Consistent Delay
We derive an alternative expression for a delayed logistic equation in which
the rate of change in the population involves a growth rate that depends on the
population density during an earlier time period. In our formulation, the delay
in the growth term is consistent with the rate of instantaneous decline in the
population given by the model. Our formulation is a modification of [Arino et
al., J.~Theoret.~Biol.~241(1):109--119, 2006] by taking the intraspecific
competition between the adults and juveniles into account. We provide a
complete global analysis showing that no sustained oscillations are possible. A
threshold giving the interface between extinction and survival is determined in
terms of the parameters in the model. The theory of chain transitive sets and
the comparison theorem for cooperative delay differential equations are used to
determine the global dynamics of the model.
We extend our delayed logistic equation to a system modeling the competition
of two species. For the competition model, we provide results on local
stability, bifurcation diagrams, and adaptive dynamics. Assuming that the
species with shorter delay produces fewer offspring at a time than the species
with longer delay, we show that there is a critical value, , such that
the evolutionary trend is for the delay to approach .Comment: 22 pages, 6 figures, 1 tabl
Calorimetric Evidence for Nodes in the Overdoped Ba(FeCo)As
We present low-temperature specific heat of the electron-doped
Ba(FeCo)As, which does not show any indication of
an upturn down to 400 mK, the lowest measuring temperature. The lack of a
Schottky-like feature at low temperatures or in magnetic fields up to 9 Tesla
enables us to identify enhanced low-temperature quasiparticle excitations and
to study anisotropy in the linear term of the specific heat. Our results can
not be explained by a single or multiple isotropic superconducting gap, but are
consistent with multi-gap superconductivity with nodes on at least one Fermi
surface sheet.Comment: 5 pages 4 figure
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