1,702 research outputs found
Periodic Solutions of a Class of Non-autonomous Second-Order Systems
AbstractSome existence theorems are obtained by the least action principle for periodic solutions of nonautonomous second-order systems with a potential which is the sum of a subconvex function and a subquadratic function
Subharmonic solutions for nonautonomous sublinear second order Hamiltonian systems
AbstractSome existence theorems are obtained for subharmonic solutions of nonautonomous second order Hamiltonian systems by the minimax methods in critical point theory
Effects of Geometrical Symmetry on the Vortex Nucleation and Penetration in Mesoscopic Superconductors
We investigate how the geometrical symmetry affects the penetration and
arrangement of vortices in mesoscopic superconductors using self-consistent
Bogoliubov-de Gennes equations. We find that the entrance of the vortex happens
when the current density at the hot spots reaches the depairing current
density. Through determining the spatial distribution of hot spots, the
geometrical symmetry of the superconducting sample influences the nucleation
and entrance of vortices. Our results propose one possible experimental
approach to control and manipulate the quantum states of mesoscopic
superconductors with their topological geometries, and they can be easily
generalized to the confined superfluids and Bose-Einstein condensates
Electroneutrality Breakdown and Specific Ion Effects in Nanoconfined Aqueous Electrolytes Observed by NMR
Ion distribution in aqueous electrolytes near the interface plays critical
roles in electrochemical, biological and colloidal systems and is expected to
be particularly significant inside nanoconfined regions. Electroneutrality of
the total charge inside nanoconfined regions is commonly assumed a priori in
solving ion distribution of aqueous electrolytes nanoconfined by uncharged
hydrophobic surfaces with no direct experimental validation. Here, we use a
quantitative nuclear magnetic resonance approach to investigate the properties
of aqueous electrolytes nanoconfined in graphitic-like nanoporous carbon.
Substantial electroneutrality breakdown in nanoconfined regions and very
asymmetric responses of cations and anions to the charging of nanoconfining
surfaces are observed. The electroneutrality breakdown is shown to depend
strongly on the propensity of anions toward the water-carbon interface and such
ion-specific response follows generally the anion ranking of the Hofmeister
series. The experimental observations are further supported by numerical
evaluation using the generalized Poisson-Boltzmann equationComment: 26 pages, 3 figure
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