The Saffman-Taylor viscous fingering instability occurs when a less viscous fluid displaces a more viscous one between narrowly spaced parallel plates in a Hele-Shaw cell. Experiments in radial flow geometry form fan-like patterns, in which fingers of different lengths compete, spread and split. Our weakly nonlinear analysis of the instability predicts these phenomena, which are beyond the scop...

We study the tunneling mechanism of nonlinear optical processes in solids induced by strong coherent laser fields. The theory is based on an extension Landau-Zener model with nonadiabatic geometric effects. In addition to rectification effect known previously, we find two effects, namely perfect and counterdiabaticity at fast sweep speed. apply this twisted Schwinger effect, i.e., pair producti...

the structures and stability of 531 novel boron nitride substituted isomers of 12-crown-4 etherverified theoretically. for a collection of 23 selected bn isomers, structural geometry, vibrationalstability, energy gaps, natural bond population analysis, and nonlinear optical responses investigatedtheoretically. the changes of standard enthalpies for ionization reactions and electron affinityreac...

We performed second harmonic generation (SHG) imaging of collagen in rat-tendon cryosections, using femtosecond laser scanning confocal microscopy, both in backscattering and transmission geometries. SHG transmission images of collagen fibers were spatially resolved due to a coherent, directional SHG component. This effect was enhanced with the use of an index-matching fluid (n(i) = 1.52). The ...

Understanding the neural control and mechanics of human eye movement has significant implications for treating vision disorders. A computational model incorporating physiological properties and nonlinear kinematics of the oculomotor plant’s geometry and extraocular muscle (EOM) mechanics is desirable for scientific studies and clinical applications. We simulate realistic three-dimensional eye f...

The photorefractive properties of semi-insulating AlGaAs-GaAs multiple quantum wells are described for the transverse Franz-Keldysh geometry with the electric field in the plane of the quantum wells. Combining the strong electroabsorption of quantum-confined excitons with the high resistivity of semi-insulating quantum wells yields large nonlinear optical sensitivities. The photorefractive quan...

We geometrically study the Legendre duality relation that plays an important role in statistical physics with the standard or generalized entropies. For this purpose, we introduce dualistic structure defined by information geometry, and discuss concepts arising in generalized thermostatistics, such as relative entropies, escort distributions and modified expectations. Further, a possible genera...