6,330 research outputs found
Effect of Sewage on Plasma Cortisol and Element Concentrations in Goldfish, Carassius auratus
開始ページ、終了ページ: 冊子体のページ付
Transport properties of double-walled carbon nanotube quantum dots
The transport properties of quantum dot (QD) systems based on double-walled
carbon nanotube (DWCNT) are investigated. The interplay between microscopic
structure and strong Coulomb interaction is treated within a bosonization
framework. The linear and nonlinear G-V-V_g characteristics of the QD system is
calculated by starting from the Liouville equation for the reduced density
matrix. Depending on the intershell couplings, an 8-electron periodicity of the
Coulomb blockade peak spacing in the case of commensurate DWCNT QDs and a
4-electron periodicity in the incommensurate case are predicted. The
contribution of excited states of DWCNTs to the nonlinear transport is
investigated as well.Comment: 18 pages, 7 figure
Glasslike vs. crystalline thermal conductivity in carrier-tuned Ba8Ga16X30 clathrates (X = Ge, Sn)
The present controversy over the origin of glasslike thermal conductivity
observed in certain crystalline materials is addressed by studies on
single-crystal x-ray diffraction, thermal conductivity k(T) and specific heat
Cp(T) of carrier-tuned Ba8Ga16X30 (X = Ge, Sn) clathrates. These crystals show
radically different low-temperature k(T) behaviors depending on whether their
charge carriers are electrons or holes, displaying the usual crystalline peak
in the former case and an anomalous glasslike plateau in the latter. In
contrast, Cp(T) above 4 K and the general structural properties are essentially
insensitive to carrier tuning. We analyze these combined results within the
framework of a Tunneling/Resonant/Rayleigh scatterings model, and conclude that
the evolution from crystalline to glasslike k(T) is accompanied by an increase
both in the effective density of tunnelling states and in the resonant
scattering level, while neither one of these contributions can solely account
for the observed changes in the full temperature range. This suggests that the
most relevant factor which determines crystalline or glasslike behavior is the
coupling strength between the guest vibrational modes and the frameworks with
different charge carriers.Comment: 8 pages, 4 figures, 4 tables, submitted to Phys. Rev.
Distinct Fe-induced magnetic states in the underdoped and overdoped regimes of La2-xSrxCu1-yFeyO4 revealed by muon spin relaxation
Zero-field and longitudinal-field muon-spin-relaxation measurements have been
performed in partially Fe-substituted La2-xSrxCu1-yFeyO4 in a wide range of
hole concentration, to investigate the magnetic state induced by the Fe
substitution recently suggested from the neutron-scattering measurements [Phys.
Rev. Lett. 107, 127002 (2011)]. It has been found that the magnetic transition
temperature is notably enhanced through the 1% Fe substitution in a wide range
of hole concentration where superconductivity appears in Fe-free La2-xSrxCuO4.
In the underdoped regime, the Fe-induced magnetic order can be understood in
terms of the concept of stripe pinning by Fe as in the case of the Zn-induced
one in La2-xSrxCu1-yZnyO4. In the overdoped regime, on the other hand, the
Fe-induced magnetic order is short-ranged, which is distinct from the stripes.
It is plausible that a spin-glass state of Fe spins derived from the
Ruderman-Kittel-Kasuya-Yosida interaction is realized in the overdoped regime,
suggesting a change of the ground state from the strongly correlated state to
the Fermi-liquid state with hole doping in La-214 high-Tc cuprates.Comment: 10 pages, 6 figures, accepted for publication in Phys. Rev.
Resonant inelastic x-ray scattering in single-crystal superconducting PrFeAsO0.7
Resonant inelastic x-ray scattering (RIXS) spectra at the Fe K-edge were
measured for a single crystal of the iron oxypnictide superconductor PrFeAsO0.7
(Tc=42 K). They disclose a weak, broad feature centered around 4.5 eV energy
loss, which is slightly resonantly enhanced when the incident energy is tuned
in the vicinity of the 4p white line. We tentatively ascribe it to the
charge-transfer excitation between As 4p and Fe 3d.Comment: 2 pages, 2 figure
A New Reconfigurable Agricultural Vehicle Controlled by a User Graphical Interface: Mechanical and Electronic Aspects
The use of innovative mobile vehicles with increasingly advanced mechatronic aspects in the agricultural sector is becoming, in recent years, a stimulating field of research and comparison. In particular, the problem addressed in the present work refers to improving the locomotion of mobile vehicles on agricultural terrain by reducing the soil damage and improve the overall performance. Agricultural vehicles generally use tracks and wheels for locomotion; the main difference between the two systems is the contact area with the ground and, consequently, the pressure distribution. The present work presents a new reconfigurable agricultural vehicle that can switch from one locomotion system to another, choosing the suitable configuration according to the terrain conditions. All the mechanical and electronic aspects of the prototype developed are analyzed together with an in-depth analysis of the management of the innovative functions through a user-friendly graphical interface able to control the vehicle
Temperature Response Comparison of Controlled and Field Environments for Four Tropical Grasses
Tropical grasses are cultivated mostly as annuals in the warm region of SW Japan. They have a long-term sowing time after harvesting temperate Italian ryegrass. We compared the early growth of tropical grasses in a controlled environment vs. field data at 2 sowing times to determine their temperate response
Rigorous results on the local equilibrium kinetics of a protein folding model
A local equilibrium approach for the kinetics of a simplified protein folding
model, whose equilibrium thermodynamics is exactly solvable, was developed in
[M. Zamparo and A. Pelizzola, Phys. Rev. Lett. 97, 068106 (2006)]. Important
properties of this approach are (i) the free energy decreases with time, (ii)
the exact equilibrium is recovered in the infinite time limit, (iii) the
equilibration rate is an upper bound of the exact one and (iv) computational
complexity is polynomial in the number of variables. Moreover, (v) this method
is equivalent to another approximate approach to the kinetics: the path
probability method. In this paper we give detailed rigorous proofs for the
above results.Comment: 25 pages, RevTeX 4, to be published in JSTA
Charmonium properties in deconfinement phase in anisotropic lattice QCD
J/Psi and eta_c above the QCD critical temperature T_c are studied in
anisotropic quenched lattice QCD, considering whether the c\bar c systems above
T_c are spatially compact (quasi-)bound states or scattering states. We adopt
the standard Wilson gauge action and O(a)-improved Wilson quark action with
renormalized anisotropy a_s/a_t =4.0 at \beta=6.10 on 16^3\times (14-26)
lattices, which correspond to the spatial lattice volume V\equiv
L^3\simeq(1.55{\rm fm})^3 and temperatures T\simeq(1.11-2.07)T_c. We
investigate the c\bar c system above T_c from the temporal correlators with
spatially-extended operators, where the overlap with the ground state is
enhanced. To clarify whether compact charmonia survive in the deconfinement
phase, we investigate spatial boundary-condition dependence of the energy of
c\bar c systems above T_c. In fact, for low-lying S-wave c \bar c scattering
states, it is expected that there appears a significant energy difference
\Delta E \equiv E{\rm (APBC)}-E{\rm (PBC)}\simeq2\sqrt{m_c^2+3\pi^2/L^2}-2m_c
(m_c: charm quark mass) between periodic and anti-periodic boundary conditions
on the finite-volume lattice. In contrast, for compact charmonia, there is no
significant energy difference between periodic and anti-periodic boundary
conditions. As a lattice QCD result, almost no spatial boundary-condition
dependence is observed for the energy of the c\bar c system in J/\Psi and
\eta_c channels for T\simeq(1.11-2.07)T_c. This fact indicates that J/\Psi and
\eta_c would survive as spatially compact c\bar c (quasi-)bound states below
2T_c. We also investigate a -wave channel at high temperature with maximally
entropy method (MEM) and find no low-lying peak structure corresponding to
\chi_{c1} at 1.62T_c.Comment: 13 pages, 11 figure
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