30,109 research outputs found
The generalized Kupershmidt deformation for constructing new integrable systems from integrable bi-Hamiltonian systems
Based on the Kupershmidt deformation for any integrable bi-Hamiltonian
systems presented in [4], we propose the generalized Kupershmidt deformation to
construct new systems from integrable bi-Hamiltonian systems, which provides a
nonholonomic perturbation of the bi-Hamiltonian systems. The generalized
Kupershmidt deformation is conjectured to preserve integrability. The
conjecture is verified in a few representative cases: KdV equation, Boussinesq
equation, Jaulent-Miodek equation and Camassa-Holm equation. For these specific
cases, we present a general procedure to convert the generalized Kupershmidt
deformation into the integrable Rosochatius deformation of soliton equation
with self-consistent sources, then to transform it into a -type
bi-Hamiltonian system. By using this generalized Kupershmidt deformation some
new integrable systems are derived. In fact, this generalized Kupershmidt
deformation also provides a new method to construct the integrable Rosochatius
deformation of soliton equation with self-consistent sources.Comment: 21 pages, to appear in Journal of Mathematical Physic
Synchronization of One Dimensional Array of Point Josephson Junctions Coupled to a Common Load
We study the synchronization in a one dimensional array of point Josephson
junctions coupled to a common capacitor, which establishes a long-range
interaction between junctions and synchronizes them. The stability diagram of
synchronization in a noise-free system is obtained. The current when junctions
transform from resistive state into superconducting state, is then calculated
and its dependence on the shunt parameters and the dissipation of junctions is
revealed. In the presence of thermal noise, the synchronized oscillations are
destroyed at a critical temperature and the system undergoes a continuous phase
transition of desynchronization. A possible stability diagram of the
synchronized oscillations with respect to thermal noise, current, dissipations
and shunt capacitance is then constructed. Finally we investigate the dynamic
relaxation from random oscillations into synchronized state. The relaxation
time increases with the system size and temperature, but is reduced by the
shunt capacitor.Comment: 11.2 pages, 14 figure
Measuring spectrum of spin wave using vortex dynamics
We propose to measure the spectrum of magnetic excitation in magnetic
materials using motion of vortex lattice driven by both ac and dc current in
superconductors. When the motion of vortex lattice is resonant with oscillation
of magnetic moments, the voltage decreases at a given current. From transport
measurement, one can obtain frequency of the magnetic excitation with the wave
number determined by vortex lattice constant. By changing the lattice constant
through applied magnetic fields, one can obtains the spectrum of the magnetic
excitation up to a wave vector of order .Comment: 4 pages, 2 figure
Microwave-induced nonequilibrium temperature in a suspended carbon nanotube
Antenna-coupled suspended single carbon nanotubes exposed to 108 GHz
microwave radiation are shown to be selectively heated with respect to their
metal contacts. This leads to an increase in the conductance as well as to the
development of a power-dependent DC voltage. The increased conductance stems
from the temperature dependence of tunneling into a one-dimensional electron
system. The DC voltage is interpreted as a thermovoltage, due to the increased
temperature of the electron liquid compared to the equilibrium temperature in
the leads
Coherent control at its most fundamental: CEP-dependent electron localization in photodissoziation of a H2+ molecular ion beam target
Measurements and calculations of the absolute carrier-envelope phase (CEP)
effects in the photodissociation of the simplest molecule, H2+, with a 4.5-fs
Ti:Sapphire laser pulse at intensities up to (4 +- 2)x10^14 Watt/cm^2 are
presented. Localization of the electron with respect to the two nuclei (during
the dissociation process) is controlled via the CEP of the ultra-short laser
pulses. In contrast to previous CEP-dependent experiments with neutral
molecules, the dissociation of the molecular ions is not preceded by a
photoionization process, which strongly influences the CEP dependence.
Kinematically complete data is obtained by time- and position-resolved
coincidence detection. The phase dependence is determined by a single-shot
phase measurement correlated to the detection of the dissoziation fragments.
The experimental results show quantitative agreement with ab inito 3D-TDSE
calculations that include nuclear vibration and rotation.Comment: new version includes minore changes and adding the supp_material.pd
Mass movement susceptibility mapping using satellite optical imagery compared with InSAR monitoring: Zigui County, Three Gorges region, China
Mass movements on steep slopes are a major hazard to
communities and infrastructure in the Three Gorges
region, China. Developing susceptibility maps of mass
movements is therefore very important in both current
and future land use planning. This study employed
satellite optical imagery and an ASTER GDEM (15 m)
to derive various parameters (namely geology; slope
gradient; proximity to drainage networks and proximity
to lineaments) in order to create a GIS-based map of
mass movement susceptibility. This map was then
evaluated using highly accurate deformation signals
processed using the Persistent Scatterer (PS) InSAR
technique. Areas of high susceptibility correspond well
to points of high subsidence, which provides a strong
support of our susceptibility map
Optical Transition and Momentum Transfer in Atomic Wave Packets
It is shown that the population Rabi-floppings in a lossless two-level atom,
interacting with a monochromatic electromagnetic field, in general are
convergent in time. The well-known continuous floppings take place because the
restricted choosing of initial conditions, that is when the atom initially is
chosen on ground or excited level before the interaction, simultaneously having
a definite value of momentum there. The convergence of Rabi-floppings in atomic
wave-packet-states is a direct consequence of Doppler effect on optical
transition rates (Rabi-frequencies): it gradually leads to ''irregular''
chaotic-type distributions of momentum in ground and excited energy levels,
smearing the amplitudes of Rabi-floppings. Conjointly with Rabi-floppings, the
coherent accumulation of momentum on each internal energy level monotonically
diminishes too.Comment: 6 pages, 10 Figure
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Comparing carbon sequestration in an oil reservoir to sequestration in a brine formation-field study
Geologic sequestration of CO2 in an oil reservoir is generally considered a different class than sequestration in
formations which contain only brine. In this paper, the significance and validity of this conceptualization is
examined by comparing the performance of CO2 injected into a depleted oil reservoir with the performance of
similar injection into non-oil bearing sandstones using a field test at Cranfield Field, Mississippi as a case study. The
differences considered are:
(1)Residual oil in the reservoir slightly reduces the CO2 breakthrough time and rate of pressure build up as
compared to a reservoir containing only brine, because under miscible conditions, more CO2 dissolves into oil
than in to brine.
(2)Dense wells provide improved assessment of the oil reservoir quality leading to improved prediction as well as
verification of CO2 movement in this reservoir as compared to the sparsely characterized brine leg. The value of
this information exceeds the risk of leakage.
Assessment of the difference made by the presence of residual oil requires a good understanding reservoir properties
to predict oil and gas distribution. Stratal slicing, attribute analysis and petrographic analyses are used to define the
reservoir architecture. Real-time pressure response at a dedicated observation well and episodic pressure mapping
has been conducted in the reservoir under flood since mid-2008; comparison measurements are planned for 2009 in
down-dip environments lacking hydrocarbons. Model results using GEM compositional simulator compare well in
general to measured reservoir response under CO2 flood; imperfections in model match of flood history document
uncertainties Time laps RST logging is underway to validate fluid composition and migration models. Monitoring
assessing the performance of the wells during the injection of CO2 suggests that the value of wells to provide field
data for characterization exceeds the risk of leakage.Bureau of Economic Geolog
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