نتایج جستجو برای: delocalization

تعداد نتایج: 2887  

2015
Juliane Q. Gong Patrick Parkinson Dmitry V. Kondratuk Guzmán Gil-Ramírez Harry L. Anderson Laura M. Herz

Conjugated polymers with cyclic structures are interesting because their symmetry leads to unique electronic properties. Recent advances in Vernier templating now allow large shape-persistent fully conjugated porphyrin nanorings to be synthesized, exhibiting unique electronic properties. We examine the impact of different conformations on exciton delocalization and emission depolarization in a ...

Journal: :Ultramicroscopy 2007
R F Egerton

We discuss various factors that determine the performance of electron energy-loss spectroscopy (EELS) and energy-filtered (EFTEM) imaging in a transmission electron microscope. Some of these factors are instrumental and have undergone substantial improvement in recent years, including the development of electron monochromators and aberration correctors. Others, such as radiation damage, delocal...

Journal: :The journal of physical chemistry. A 2009
Chunxing She James E McGarrah Suk Joong Lee Joshua L Goodman SonBinh T Nguyen J A G Williams Joseph T Hupp

Solution-phase transient dc photoconductivity (TDCP) measurements are used to address the question of exciton localization/delocalization in strongly coupled oligomeric porphyrins and in well-defined, higher-order assemblies of oligomers (ladder and prism assemblies). The approach used is determination of the excited-state excess polarizability volume, Delta alpha(V)--a quantity known to report...

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2012
Cathal Smyth Francesca Fassioli Gregory D Scholes

We review various methods for measuring delocalization in light-harvesting complexes. Direct relations between inverse participation ratios (IPRs) and entanglement measures are derived. The B850 ring from the LH2 complex in Rhodopseudomonas acidophila is studied. By analysing electronic energy transfer dynamics in the B850 ring using different metrics for quantifying excitonic delocalization, w...

1997
Joshua Feinberg

We study localization and delocalization in a class of non-hermitean Hamiltonians inspired by the problem of vortex pinning in superconductors. In various simplified models we are able to obtain analytic descriptions, in particular of the non-perturbative emergence of a forked structure (the appearance of “wings”) in the density of states. We calculate how the localization length diverges at th...

Journal: :Chemical communications 2009
Mamoru Fujitsuka Sachiko Tojo Teruo Shinmyozu Tetsuro Majima

Intramolecular dimer radical anions of [3n]cyclophanes generated by gamma-ray irradiation in low-temperature glassy matrices showed an absorption band attributable to charge resonance around 936-1210 nm, from which the stabilization energy of the dimer radical anions were analyzed on the basis of pi-electron delocalization over two benzene rings and the damping factor (beta) was estimated to be...

2005
B. R. Maddox A. Lazicki C. S. Yoo V. Iota M. Chen A. K. McMahan M. Y. Hu P. Chow R. T. Scalettar W. E. Pickett

We present resonant inelastic x-ray scattering (RIXS) and x-ray emission spectroscopy (XES) results which suggest Kondo-like aspects in the delocalization of 4f electrons in Gd metal to 113 GPa. Analysis of the RIXS data reveal a prolonged and continuous process throughout the entire pressure range, so that the volume collapse transition at 59 GPa is only part of the delocalization phenomenon. ...

2008
Enza Orlandi

We prove a finite volume lower bound of the order √ logN on the delocalization of a disordered continuous spin model (resp. effective interface model) in d = 2 in a box of size N . The interaction is assumed to be massless, possibly anharmonic and dominated from above by a Gaussian. Disorder is entering via a linear source term. For this model delocalization with the same rate is proved to take...

1998
Sumati Surya Donald Marolf

We address the delocalization of low dimensional D-branes and NS-branes when they are a part of a higher dimensional BPS black brane, and the homogeneity of the resulting horizon. We show that the effective delocalization of such branes is a classical effect that occurs when localized branes are brought together. Thus, the fact that the few known solutions with inhomogeneous horizons are highly...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید