Excitation gaps are of considerable significance in electronic structure theory. Two different gaps are of particular interest. The fundamental gap is defined by charged excitations, as the difference between the first ionization potential and the first electron affinity. The optical gap is defined by a neutral excitation, as the difference between the energies of the lowest dipole-allowed exci...

Onset and termination of electric stimulation may result in "make" and "break" excitation of the heart tissue. Wikswo et al. (30) explained both types of stimulations by virtual electrode polarization. Make excitation propagates from depolarized regions (virtual cathodes). Break excitation propagates from hyperpolarized regions (virtual anodes). However, these studies were limited to strong sti...

We use time-dependent density functional theory and time-dependent ZINDO (a semi-empirical method) to study transfer of an extra electron between a pair of pentacene molecules. A measure of the electronic transfer integral is computed in a dynamic picture via the vertical excitation energy from a delocalized anionic ground state. With increasing dimer separation, this dynamical measurement of c...

Coherent transient excitation of the spin ground states in singly charged quantum dots creates optically coupled and decoupled states of the electron spin. We demonstrate selective excitation from the spin ground states to the trion state through phase sensitive control of the spin coherence via these three states, leading to partial rotations of the spin vector. This progress lays the ground w...

Triggering of long-lived nuclear isomeric states via coupling to the atomic shells in the process of nuclear excitation by electron capture (NEEC) is studied. NEEC occurring in highly charged ions can excite the isomeric state to a triggering level that subsequently decays to the ground state. We present total cross sections for NEEC isomer triggering considering experimentally confirmed low-ly...

[1] Leaky wave excitation on three-dimensional, via-fed single and coupled microstrip interconnects is studied. Closed-form asymptotic expressions for the fields associated with the interconnect are derived and are applied in the traveling/standing wave and leaky wave regimes, both of which lead to radiation. The leaky wave beam angle is found to correspond to the usual two-dimensional ray opti...

The conversion of kinetic energy into target-like fragment excitation and orbital angular momentum into fragment spin has been studied in the reaction 333 MeV Si with ' 'Ta. The light charged particles were detected in a small, highly segmented, 4m phoswich detector system placed in the spin spectrometer, a 4m NaI array which served as a neutron and gamma detector. Multiplicities of light charg...

For the realization of noninvasive and regional myocardial tissue characterization, in the present study, we attempted to elucidate the characteristics of the myocardial response to electrical excitation and its propagation by an ex vivo experiment using a rat left ventricular wall. To visualize such a propagation phenomenon, whose speed is up to several m/s, high-frame-rate ultrasound was used...

As the leading cause of death in the United States, heart disease has become a principal concern in modern society. Cardiac arrhythmias can be caused by a dysregulation of calcium dynamics in cardiomyocytes. Calcium dysregulation, however, is not yet fully understood and is not easily predicted; this provides motivation for the subsequent research. Excitation-contraction coupling (ECC) is the p...