The Experts below are selected from a list of 72537 Experts worldwide ranked by ideXlab platform
Bo Zhao - One of the best experts on this subject based on the ideXlab platform.
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observation of a Threshold Behavior in an ultracold endothermic atom exchange process involving feshbach molecules
Physical Review A, 2019Co-Authors: Huan Yang, Bo ZhaoAbstract:Chemical reactions at ultracold temperature provide an ideal platform to study chemical reactivity at the fundamental level, and to understand how chemical reactions are governed by quantum mechanics. Recent years have witnessed the remarkable progress in studying ultracold chemistry with ultracold molecules. However, these works were limited to exothermic reactions. The direct observation of state-to-state ultracold endothermic reaction remains elusive. Here we report on the investigation of endothermic and nearly thermoneutral atom-exchange reactions in an ultracold atom-dimer mixture. By developing an indirect reactant-preparation method based on a molecular bound-bound transition, we are able to directly observe a universal endothermic reaction with tunable energy Threshold and study the state-to-state reaction dynamics. The reaction rate coefficients show a strikingly Threshold phenomenon. The influence of the reverse reaction on the reaction dynamics is observed for the endothermic and nearly thermoneutral reactions. We carry out zero-range quantum mechanical scattering calculations to obtain the reaction rate coefficients, and the three-body parameter is determined by comparison with the experiments. The observed endothermic and nearly thermoneutral reaction may be employed to implement collisional Sisyphus cooling of molecules, study the chemical reactions in degenerate quantum gases and conduct quantum simulation of Kondo effect with ultracold atoms.
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observation of a Threshold Behavior in an ultracold endothermic atom exchange process involving feshbach molecules
Physical Review A, 2019Co-Authors: Y Liu, Bo Zhao, Huan Yang, Jue Nan, D Zhang, Lan Liu, Jun Rui, Jianwei PanAbstract:We report on the investigation of endothermic and nearly thermoneutral atom-exchange collisions in an ultracold atom-dimer mixture. By developing an indirect preparation method based on a molecular bound-bound transition, we are able to directly observe an endothermic collision with a tunable energy Threshold and study the state-to-state collision dynamics. The collision rate coefficients show a striking Threshold phenomenon. The influence of the reverse process on the collision dynamics is observed for the endothermic and nearly thermoneutral collisions. We carry out zero-range quantum-mechanical scattering calculations to obtain the collision rate coefficients, and the three-body parameter is determined by comparison with the experiments. The observed endothermic and nearly thermoneutral collisions may be employed to implement quantum simulation of the Kondo effect with ultracold molecules.
Huan Yang - One of the best experts on this subject based on the ideXlab platform.
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observation of a Threshold Behavior in an ultracold endothermic atom exchange process involving feshbach molecules
Physical Review A, 2019Co-Authors: Huan Yang, Bo ZhaoAbstract:Chemical reactions at ultracold temperature provide an ideal platform to study chemical reactivity at the fundamental level, and to understand how chemical reactions are governed by quantum mechanics. Recent years have witnessed the remarkable progress in studying ultracold chemistry with ultracold molecules. However, these works were limited to exothermic reactions. The direct observation of state-to-state ultracold endothermic reaction remains elusive. Here we report on the investigation of endothermic and nearly thermoneutral atom-exchange reactions in an ultracold atom-dimer mixture. By developing an indirect reactant-preparation method based on a molecular bound-bound transition, we are able to directly observe a universal endothermic reaction with tunable energy Threshold and study the state-to-state reaction dynamics. The reaction rate coefficients show a strikingly Threshold phenomenon. The influence of the reverse reaction on the reaction dynamics is observed for the endothermic and nearly thermoneutral reactions. We carry out zero-range quantum mechanical scattering calculations to obtain the reaction rate coefficients, and the three-body parameter is determined by comparison with the experiments. The observed endothermic and nearly thermoneutral reaction may be employed to implement collisional Sisyphus cooling of molecules, study the chemical reactions in degenerate quantum gases and conduct quantum simulation of Kondo effect with ultracold atoms.
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observation of a Threshold Behavior in an ultracold endothermic atom exchange process involving feshbach molecules
Physical Review A, 2019Co-Authors: Y Liu, Bo Zhao, Huan Yang, Jue Nan, D Zhang, Lan Liu, Jun Rui, Jianwei PanAbstract:We report on the investigation of endothermic and nearly thermoneutral atom-exchange collisions in an ultracold atom-dimer mixture. By developing an indirect preparation method based on a molecular bound-bound transition, we are able to directly observe an endothermic collision with a tunable energy Threshold and study the state-to-state collision dynamics. The collision rate coefficients show a striking Threshold phenomenon. The influence of the reverse process on the collision dynamics is observed for the endothermic and nearly thermoneutral collisions. We carry out zero-range quantum-mechanical scattering calculations to obtain the collision rate coefficients, and the three-body parameter is determined by comparison with the experiments. The observed endothermic and nearly thermoneutral collisions may be employed to implement quantum simulation of the Kondo effect with ultracold molecules.
Jianwei Pan - One of the best experts on this subject based on the ideXlab platform.
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observation of a Threshold Behavior in an ultracold endothermic atom exchange process involving feshbach molecules
Physical Review A, 2019Co-Authors: Y Liu, Bo Zhao, Huan Yang, Jue Nan, D Zhang, Lan Liu, Jun Rui, Jianwei PanAbstract:We report on the investigation of endothermic and nearly thermoneutral atom-exchange collisions in an ultracold atom-dimer mixture. By developing an indirect preparation method based on a molecular bound-bound transition, we are able to directly observe an endothermic collision with a tunable energy Threshold and study the state-to-state collision dynamics. The collision rate coefficients show a striking Threshold phenomenon. The influence of the reverse process on the collision dynamics is observed for the endothermic and nearly thermoneutral collisions. We carry out zero-range quantum-mechanical scattering calculations to obtain the collision rate coefficients, and the three-body parameter is determined by comparison with the experiments. The observed endothermic and nearly thermoneutral collisions may be employed to implement quantum simulation of the Kondo effect with ultracold molecules.
Daqing Jiang - One of the best experts on this subject based on the ideXlab platform.
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Threshold Behavior in two types of stochastic three strains influenza virus models
Physica A-statistical Mechanics and Its Applications, 2020Co-Authors: Qun Liu, Daqing Jiang, Tasawar Hayat, Ahmed Alsaedi, Bashir AhmadAbstract:Abstract In this paper, we study two types of stochastic models consisting of three strains of influenza. For each type of the stochastic model, we establish sufficient conditions for extinction and persistence in the mean of these diseases by using the stochastic Lyapunov analysis method. Meanwhile, we obtain the Threshold between persistence in the mean and extinction of the diseases.
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Threshold Behavior in a stochastic delayed sis epidemic model with vaccination and double diseases
Journal of The Franklin Institute-engineering and Applied Mathematics, 2019Co-Authors: Qun Liu, Daqing Jiang, Tasawar Hayat, Ahmed AlsaediAbstract:Abstract In this paper, we investigate the Threshold dynamics of a stochastic delayed SIS epidemic model with vaccination and double diseases which make the research more difficult. We establish sufficient conditions for extinction and persistence in the mean of the two diseases. We also obtain the Threshold between persistence in the mean and extinction of the stochastic system. It is shown that: (i) time delay and environmental white noise have important effects on the persistence and extinction of the two diseases; (ii) the two diseases can coexist under certain conditions. Finally, some numerical simulations are provided to demonstrate the analytical results.
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Threshold Behavior of a stochastic lotka volterra food chain chemostat model with jumps
Physica A-statistical Mechanics and Its Applications, 2019Co-Authors: Miaomiao Gao, Daqing Jiang, Tasawar Hayat, Ahmed AlsaediAbstract:Abstract Taking levy jumps into account, a Lotka–Volterra food chain chemostat model in random environment is proposed and investigated. We first prove the existence and uniqueness of the global positive solution. Then conditions for extinction of the microorganisms are derived in two cases. Furthermore, we establish sufficient conditions for persistence in the mean of the system. Theoretical analysis indicates that the dynamics of the considered model are determined by two Threshold parameters R 0 s and R 1 s , and both white noise and levy noise are disadvantageous to the system. Finally, numerical simulations are given to illustrate the results.
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Threshold Behavior in a stochastic siqr epidemic model with standard incidence and regime switching
Applied Mathematics and Computation, 2018Co-Authors: Daqing JiangAbstract:This paper is concerned with the dynamical Behavior of a stochastic SIQR epidemic model with standard incidence which is disturbed by both white and telegraph noises. Firstly, we obtain sufficient conditions for persistence in the mean of the disease. Then we establish sufficient conditions for extinction of the disease. In addition, in the case of persistence, we get sufficient conditions for the existence of positive recurrence of the solutions by constructing a suitable stochastic Lyapunov function with regime switching. Meanwhile, the Threshold between persistence in the mean and extinction of the stochastic system is also obtained. Finally, some numerical simulations are introduced to demonstrate the analytical results.
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Threshold Behavior in a stochastic sis epidemic model with standard incidence
Journal of Dynamics and Differential Equations, 2014Co-Authors: Yuguo Lin, Daqing JiangAbstract:In this paper, we consider a stochastic SIS epidemic model with perturbed disease transmission coefficient. We discuss the Threshold Behavior in the sense that if \(\mathcal {R}_0^s 1\), the densities of the distributions of the solution can converge in \(L^1\) to an invariant density.
S H Glenzer - One of the best experts on this subject based on the ideXlab platform.
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observation of the density Threshold Behavior for the onset of stimulated raman scattering in high temperature hohlraum plasmas
Physical Review Letters, 2009Co-Authors: D H Froula, T Doppner, L Divol, R A London, R L Berger, N B Meezan, J S Ross, L J Suter, C Sorce, S H GlenzerAbstract:We show that the measured stimulated Raman scattering (SRS) in a large-scale high-temperature plasma scales strongly with the plasma density, increasing by an order of magnitude when the electron density is increased by 20%. This is consistent with linear theory, including pump depletion, in a uniform plasma and, as the density is typically constrained by other processes, this effect will set a limit on drive laser beam intensity for forthcoming ignition experiments at the National Ignition Facility. Control of SRS at laser intensities consistent with 285 eV ignition hohlraums is achieved by using polarization smoothing which increases the intensity Threshold for the onset of SRS by 1.6 +/- 0.2. These results were quantitatively predicted by full beam three-dimensional numerical laser-plasma interaction simulations.
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observation of the density Threshold Behavior for the onset of stimulated raman scattering in high temperature hohlraum plasmas
Physical Review Letters, 2009Co-Authors: D H Froula, T Doppner, L Divol, R A London, R L Berger, N B Meezan, J S Ross, L J Suter, C Sorce, S H GlenzerAbstract:We show that the measured stimulated Raman scattering (SRS) in a large-scale high-temperature plasma scales strongly with the plasma density, increasing by an order of magnitude when the electron density is increased by 20%. This is consistent with linear theory, including pump depletion, in a uniform plasma and, as the density is typically constrained by other processes, this effect will set a limit on drive laser beam intensity for forthcoming ignition experiments at the National Ignition Facility. Control of SRS at laser intensities consistent with 285 eV ignition hohlraums is achieved by using polarization smoothing which increases the intensity Threshold for the onset of SRS by $1.6\ifmmode\pm\else\textpm\fi{}0.2$. These results were quantitatively predicted by full beam three-dimensional numerical laser-plasma interaction simulations.
