The investigation on anomalous isotope effect coefficient of LaSrCuO superconductor

In this research, the anomalous isotope effect coefficient of LaSrCuO superconductor was investigated in the weak-coupling method. The constant and van Hove singularity density of state, pseudogap, and the form of pseudogap temperature dependence on critical temperature are included in our calculation. Finally, the numerical results are shown in comparison with the experimental data of LaSrCuO superconductor. We found that the van Hove singularity density of state and the inversely relation of pseudogap temperature and critical temperature can fit well with the anomalous isotope effect coefficient data of LaSrCuO superconductor.

Solving 2-D Slamming Problems by the MPS Method With Source Term Correction

An improved moving particle semi-implicit (MPS) method was developed to solve water entry problems. The traditional mixed source term was modified based on a prediction-correction scheme to suppress pressure oscillations. An improved free surface identification method was implemented for fluid computations. A weak coupling method was adopted for fluid-structure interaction. The structures were modeled by isotropic linear elastic particles. The application of the source term correction method leads to a better pressure prediction and therefore a more accurate interaction between the fluid and the structure. Validation studies were carried out for water entry of two rigid wedges, a rigid ship section, and a flexible wedge. The results by the present MPS method are in good agreement with experimental data and other published numerical results.

Parameterization of stochastic multiscale triads

We discuss applications of a recently developed method for model reduction based on linear response theory of weakly coupled dynamical systems. We apply the weak coupling method to simple stochastic differential equations with slow and fast degrees of freedom. The weak coupling model reduction method results in general in a non-Markovian system; we therefore discuss the Markovianization of the system to allow for straightforward numerical integration. We compare the applied method to the equations obtained through homogenization in the limit of large timescale separation between slow and fast degrees of freedom. We numerically compare the ensemble spread from a fixed initial condition, correlation functions and exit times from a domain. The weak coupling method gives more accurate results in all test cases, albeit with a higher numerical cost.

Parametrization of stochastic multiscale triads

We discuss applications of a recently developed method for model reduction based on linear response theory of weakly coupled dynamical systems. We apply the weak coupling method to simple stochastic differential equations with slow and fast degrees of freedom. The weak coupling model reduction method results in general in a non-Markovian system, we therefore discuss the Markovianization of the system to allow for straightforward numerical integration. We compare the applied method to the equations obtained through homogenization in the limit of large time scale separation between slow and fast degrees of freedom. We numerically compare the ensemble spread from a fixed initial condition, correlation functions and exit times from a domain. The weak coupling method gives more accurate results in all test cases, albeit with a higher numerical cost.

EXPERIMENTAL TRACKING OF UNSTABLE ORBITS IN DRIVEN DIODE RESONATOR BY WEAK COUPLING

The weak coupling method is demonstrated to stabilize and track the unstable orbits in the diode resonator system. Continuous tracking of the unstable orbits could be achieved over a wide range from the periodic down to the deep chaotic regime as the control parameter is varied continuously without changing the feedback control parameter. During the tracking of unstable orbits, hysteresis as well as switching of the attractors are observed and these are supposed to be the generic properties of continuous tracking.