Surface physical changes (disorder and/or damage) due to femtosecond pulsed laser irradiation are observed in a new regime of extremely low laser fluence (,1023 of the single shot damage fluence) and large number of laser shots (.1010). No bulk damage was detected. The surface disorder is reversible by thermal annealing at 580 ±C. We propose a new mechanism for femtosecond laser-induced surface...

We derive an exact representation of the exchange-correlation energy within density functional theory (DFT) which spawns a class of approximations leading to correct long-range asymptotic behavior. Using a simple approximation, we develop an electronic structure theory that combines a new local correlation energy (based on Monte Carlo calculations applied to the homogeneous electron gas) and a ...

Transition state theory (TST) provides a simple interpretation of many thermally activated processes. It applies successfully on timescales and length scales that differ several orders of magnitude: to chemical reactions, breaking of chemical bonds, unfolding of proteins and RNA structures and polymers crossing entropic barriers. Here we apply TST to out-of-equilibrium transport through confine...

s From The 2012 Meeting Of The Association Of Surgeons In Training

Electrical interactions between molecular vibrations can be non-linear and thereby produce intermolecular coupling even in the absence of a chemical bond. We use this fact to detect the formation of an intermolecular complex using electron-vibration-vibration two-dimensional infrared spectroscopy (EVV 2DIR) and also to determine the distance and angle between the two molecular species.

bonding brackets to the enamel surface has gained much popularity today. new adhesive systems have been introduced and marketed and a considerable increase in research regarding bond strength has been published. a considerable amount of these studies deal with shear bond strength of adhesives designed for orthodontic purpose. previous studies have used variety of test designs. this diversity in...

Bosonic and fermionic Hubbard models on the checkerboard lattice are studied numerically for infinite on-site repulsion. At particle density n=1/4 and strong nearest-neighbor repulsion, insulating Valence-Bond crystals (VBC) of resonating particle pairs are stabilized. Their melting into superfluid or metallic phases under increasing hopping is investigated at T=0 K. We identify a novel and unc...

Ultrafast electron diffraction is a unique method for the studies of structural changes of complex molecular systems. In this contribution, we report direct ultrafast electron diffraction study of the evolution of short-lived intermediates in the course of a chemical change. Specifically, we observe the transient intermediate in the elimination reaction of 1,2-diiodotetrafluoroethane (C2F4I2) t...