2,012 research outputs found
Asymmetric sequential Landau-Zener dynamics of Bose condensed atoms in a cavity
We explore the asymmetric sequential Landau-Zener (LZ) dynamics in an
ensemble of interacting Bose condensed two-level atoms coupled with a cavity
field. Assuming the couplings between all atoms and the cavity field are
identical, the interplay between atom-atom interaction and detuning may lead to
a series of LZ transitions. Unlike the conventional sequential LZ transitions,
which are symmetric to the zero detuning, the LZ transitions of Bose condensed
atoms in a cavity field are asymmetric and sensitively depend on the photon
number distribution of the cavity. In LZ processes involving single excitation
numbers, both the variance of the relative atom number and the step slope of
the sequential population ladder are asymmetric, and the asymmetry become more
significant for smaller excitation numbers. Furthermore, in LZ processes
involving multiple excitation numbers, there may appear asymmetric population
ladders with decreasing step heights. During a dynamical LZ process, due to the
atom-cavity coupling, the cavity field shows dynamical collapse and revivals.
In comparison with the symmetric LZ transitions in a classical field, the
asymmetric LZ transitions in a cavity field originate from the
photon-number-dependent Rabi frequency. The asymmetric sequential LZ dynamics
of Bose condensed atoms in a cavity field may open up a new way to explore the
fundamental many-body physics in coupled atom-photon systems.Comment: 14 pages, 6 figure
A Model of Two-Way Selection System for Human Behavior
We propose a model of two-way selection system. It appears in the processes
like choosing a mate between men and women, making contracts between job
hunters and recruiters, and trading between buyers and sellers. In this paper,
we propose a model of two-way selection system, and present its analytic
solution for the expectation of successful matching total and the regular
pattern that the matching rate trends toward an inverse proportion to either
the ratio between the two sides or the ratio of the state total to the smaller
people number. The proposed model is verified by empirical data of the
matchmaking fairs. Results indicate that the model well predicts this typical
real-world two- way selection behavior to the bounded error extent, thus it is
helpful for understanding the dynamics mechanism of the real-world two-way
selection system.Comment: 8 pages, 4 figure
2-(1,2-Dimethyl-1H-indol-3-yl)-1-{5-[3-(1,3-dioxolan-2-yl)phenyl]-2-methylthiophen-3-yl}-3,3,4,4,5,5-hexafluorocyclopent-1-ene
The title compound, C29H23F6NO2S, a member of a new family of photochromic diarylethene compounds having an unsymmetrically substituted hexafluorocyclopentene unit, displays dihedral angles between the indole and thiophene rings of 52.5 (4)°, and between the indole ring and the planar C—C=C—C unit of the cyclopentene ring of 53.8 (6)°. The distance between the potentially reactive C atoms from the two heteroaryl substituents of 3.817 (6) Å is proven to be short enough for photocyclization to occur
Displacement sensor with a wide dynamic range based on a balloon-like long-period fiber grating
ObjectiveAiming at the problem of the narrow dynamic range of current optical fiber displacement sensors, a balloon-like long-period fiber grating (LPFG) displacement sensor with a simple structure and easy preparation method is designed. MethodsBased on simulation and optimization by RSOFT software, the measurement range is determined by the balloon-like optical fiber under different curvatures. A multimode fiber balloon-like LPFG (MMF-BLPFG) formed by periodically embedding multimode fiber (MMF) into single-mode fiber (SMF) provides a reference peak for measuring the displacement. Using a precise continuous cutting device as the experimental basis, test samples consistent with the simulation results are prepared for testing. ResultsThe maximum displacement measurement range of 36 mm is achieved by measuring the drift of two resonance peaks. ConclusionsThe proposed sensor has good application potential in large-scale measurement scenarios such as the stability measurement and continuous monitoring of the underwater drainage space piping systems of ships
Poly[[bis(acetonitrile-κN)bis[μ2-2,2′-(methylenedithio)bis(1,3,4-thiadiazole)-κ2 N 4:N 4′]copper(II)] bis(perchlorate) acetonitrile solvate]
In the title compound, {[Cu(C5H4N4S4)2(C2H3N)2](ClO4)2·C2H3N}n, the CuII atom occupies a crystallographic inversion centre and is six-coordinated by six N atoms of four symmetry-related 2,2′-(methylenedithio)bis(1,3,4-thiadiazole) (L) ligands and two acetonitrile molecules in a slightly distorted octahedral geometry. The ligand L adopts an N:N′-bidentate bridging mode in a trans configuration, bridging the Cu atoms via translation symmetry, forming a two-dimensional layer-like structure. The perchlorate ions serve as acceptors for intermolecular C—H⋯O hydrogen bonds, which link the layers into a three-dimensional network. The ClO4
− anion is disordered with an occupation ratio of 0.658:0.342
Local and global polarization of hyperons across RHIC-BES energies: the roles of spin hall effect, initial condition and baryon diffusion
We perform a systematic study on the local and global spin polarization of
and hyperons in relativistic heavy-ion
collisions at beam energy scan energies via the (3+1)-dimensional CLVisc
hydrodynamics model with AMPT and SMASH initial conditions. Following the
quantum kinetic theory, we decompose the polarization vector as the parts
induced by thermal vorticity, shear tensor and the spin Hall effect (SHE). We
find that the polarization induced by SHE and the total polarization strongly
depends on the initial conditions. At GeV, SHE gives a sizeable
contribution and even flips the sign of the local polarization along the beam
direction for AMPT initial condition, which is not observed for SMASH initial
condition. Meanwhile, the local polarization along the out-of-plane direction
induced by SHE with AMPT initial condition does not always increase with
decreasing collision energies. Next, we find that the polarization along the
beam direction is sensitive to the baryon diffusion coefficient, but the local
polarization along the out-of-plane direction is not. Our results for the
global polarization of and agree well with the
STAR data. Interestingly, the global polarization of is
not always larger than that of due to various competing effects. Our
findings are helpful for understanding the polarization phenomenon and the
detailed structure of quark-gluon plasma in relativistic heavy-ion collisions.Comment: 13 pages, 8 figure
Glucose Sensing Optionally in Optical and Optoelectrical Modes Based on Au-TiO2 Schottky Nanojunctions
Abstract: In recent years, metallic nanostructures have been extensively researched in the field of plasmonic for optical and optoelectronic applications such as biochemical sensing. However, an additional optoelectronic converter or spectrometer is usually required for the sensing application. Herein, the orderly-patterned Au-TiO2 Schottky junction with an Al film that we coupled, which simultaneously works as an optical reflector and conducting layer, can achieve optical sensing of glucose by exciting surface plasmon resonance associated with the environment, and meanwhile can realize glucose detection with direct electrical-signal readout by collecting the photogenerated carriers inside the Au nanostructures and TiO2 film. When used in optical mode, the designed sensor shows a sensing sensitivity of up to 1200.0 nmRIU-1 in numerical calculation, and the measured value is 346.1 nmRIU-1. When used in optoelectrical mode, the glucose sensor under one-sun illumination obtains a sensitivity of 70.0 µAM-1cm-2 in the concentration range of 0–10 mM, with a detection limit of 0.05 µM (Signal/Noise=3). Simulation and experimental results demonstrated that the Al-film-coupled Au-TiO2 Schottky nanojunction can monitor glucose concentration optionally in optical and optoelectrical modes, which presents an alternative route to the miniaturized, portable, and multi-functioned sensors
catena-Poly[[[bis[2,2′-(propane-1,3-diyldithio)bis(1,3,4-thiadiazole)-κN 4]copper(II)]-bis[μ-2,2′-(propane-1,3-diyldithio)bis(1,3,4-thiadiazole)-κ2 N 4:N 4′]] bis(perchlorate)]
In the title compound, {[Cu(C7H8N4S4)4](ClO4)2}n, the CuII atom, occupying a crystallographic inversion centre, is six-coordinated by six N atoms of three symmetry-related 2,2′-(propane-1,3-diyldithio)bis(1,3,4-thiadiazole) (L) ligands in a slightly distorted octahedral geometry. The ligand L adopts two kinds of coordination modes in the crystal structure; one is a monodentate coordination mode and serves to complete the octahedral coordination of the Cu atom and the other is an N:N′-bidentate bridging mode in a trans configuration, bridging Cu atoms via translation symmetry along the b axis into a chain structure. The perchlorate ions serve as acceptors for intermolecular C—H⋯O hydrogen bonds, which link the chains into a three-dimensional network
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