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Pershin Anton - - 2012
The photoelectric power conversion efficiency of polymer solar cells is till now, compared to conventional inorganic solar cells, still relatively low with maximum values ranging from 7% to 8%. This essentially relates to the existence of exciton and charge carrier loss phenomena, reducing the performance of polymer solar cells significantly. ...
Colla Thiago E - - 2012
The thermodynamic properties of highly charged colloidal suspensions in contact with a salt reservoir are investigated in the framework of the renormalized Jellium model (RJM). It is found that the equation of state is very sensitive to the particular thermodynamic route used to obtain it. Specifically, the osmotic pressure calculated ...
McLaughlin Keith - - 2012
A highly accurate aniostropic intermolecular potential for diatomic hydrogen has been developed that is transferable for molecular modeling in heterogeneous systems. The potential surface is designed to be efficacious in modeling mixed sorbates in metal-organic materials that include sorption interactions with charged interfaces and open metal sites. The potential parameters ...
Hausmann Ralf - - 2012
PURPOSE OF REVIEW: Each day, the human kidneys filter about 140 l of primary urine from plasma. Although this ultrafiltrate is virtually free of plasma protein, the glomerular filter never clogs under physiological conditions. Upto today it is still not entirely resolved as to how the kidney accomplishes this extraordinary task. ...
Kim Mun Dae - - 2012
We study a readout scheme of a superconducting flux qubit state with a Cooper pair box as a transmon. The qubit states consist of the superpositions of two degenerate states where the charge and phase degrees of freedom are entangled. Owing to the robustness of the transmon against external fluctuations, ...
Zheng Haiwu - - 2012
BiFeO(3) (BFO) microspheres were synthesized by a facile hydrothermal method. The optical absorption spectrum indicates that on site Fe(3+) crystal-field transitions and the charge transfer excitations can be observed. Magnetic measurements show a spin-glass behavior and room temperature weak ferromagnetism. The surface photovoltage spectroscopy of the BFO shows two response ...
Dufaux Thomas - - 2012
Charge recombination dynamics in semiconductor nanostructures is of vital importance for photovoltaic or photodetector device applications. We use local photocurrent measurements to explore spatially separated drift- and diffusion-currents close to the edge of gold contacts on top of cadmium sulfide nanowires. By theoretical modeling of the experimental photocurrent profiles, the ...
La Mantia Fabio - - 2012
A theoretical treatment of a Schottky barrier dynamic response is developed on the basis of a general model of a semiconductor with thickness comparable in length to the space charge region width. It is shown that, when the space charge region approaches the metal/semiconductor interface, the electric field at this ...
Berthelot Johann - - 2012
Amplifying local electromagnetic fields by engineering optical interactions between individual constituents of an optical antenna is considered fundamental for efficient nonlinear wavelength conversion in nanometer-scale devices. In contrast to this general statement we show that high field enhancement does not necessarily lead to an optimized nonlinear activity. In particular, we ...
Duan Ning - - 2012
We report a normal incidence Ge/Si avalanche photodiode with separate-absorption-charge-multiplication (SACM) structure by selective epitaxial growth. By proper design of charge and multiplication layers and by optimizing the electric field distribution in the depletion region to eliminate germanium impact-ionization at high gain, a high responsivity of 12 A/W and a ...
Zhang Peng - - 2012
We describe an Ewald-summation method to incorporate long-range electrostatic interactions into fragment-based electronic structure methods for periodic systems. The present method is an extension of the particle-mesh Ewald technique for combined quantum mechanical and molecular mechanical (QM/MM) calculations, and it has been implemented into the explicit polarization (X-Pol) potential to ...
Kučera Ondřej - - 2012
Spontaneous mechanical oscillations were predicted and experimentally proven on almost every level of cellular structure. Besides morphogenetic potential of oscillatory mechanical force, oscillations may drive vibrations of electrically polar structures or these structures themselves may oscillate on their own natural frequencies. Vibrations of electric charge will generate oscillating electric field, ...
Yu Junjie - - 2012
We describe a kind of true 3D array of focused vortices with tunable topological charge, called the 3D Dammann vortex array. This 3D Dammann vortex array is arranged into the structure of a true 3D lattice in the focal region of a focusing objective, and these focused vortices are located ...
Feng Yejun - - 2012
Quantum criticality is a central concept in condensed matter physics, but the direct observation of quantum critical fluctuations has remained elusive. Here we present an X-ray diffraction study of the charge density wave (CDW) in 2H-NbSe(2) at high pressure and low temperature, where we observe a broad regime of order ...
Kashyap Hemant K - - 2012
Structural patterns that have the same spatial periodicity but a phase offset give rise to peaks and anti-peaks (negative-going peaks) at the same q value in the SAXS structure function S(q). As an example, in ionic liquids we often find charge alternation, and at the distance where one finds a ...
Vaity Pravin - - 2012
We make optical vortices of different topological charge and diffract them through a quadratic phase mask using the same spatial light modulator. This phase mask shows the diffraction in which the positive diffracted order has different dynamics than the negative diffracted order. The diffraction pattern and its orientation depend on ...
Chen Y - - 2012
Bias stress effect in "air-gap" organic field-effect transistors is investigated in the absence of a material gate dielectric, dependent only on the semiconductor's properties. It is stronger with increasing density of trap states in the semiconductor. A general theoretical model based on carrier trapping and relaxation in localized tail states ...
Skab Ihor - - 2012
We show that a system of glass disks compressed along their diameters enables one to induce a doubly charged vortex beam in the emergent light when the incident light is circularly polarized. Using such a disk system, one can control the efficiency of conversion of the spin angular momentum to ...
Agana Bernard A - - 2012
Electro-ultrafiltration is a method that can be employed for treating wastewater containing charged particles. In this method, an electric field produced by an applied voltage influences the movement and electrophoretic mobility of the charged particles - minimizing concentration polarization and improving permeate flux. The present study has evaluated the influence ...
Domingos Sérgio R - - 2012
We have observed large second-order nonlinear optical and vibrational circular dichroism (VCD) responses in a charge-transfer-type L-Histidinium salt. Using X-ray Diffraction, VCD spectroscopy, and time-dependent density functional theory to characterize the compound, we employ a two-level model to explain and quantify the strongly enhanced optical signals. We find that both ...
Skorb Ekaterina V - - 2012
Porous silicon with unique optical properties was formed through an ultrasonication method. This technique allows the one step formation of silicon with a purposefully variable porous structure, provides for the possibility of patterned surface-selective modification, and forms photoluminescent centers and defect states, which can act as centers for charge separation.
Weng Shih-Chang - - 2012
Charge disproportion at octahedral Fe sites in magnetite was observed at low temperature using two inversion-symmetry related three-wave resonant x-ray diffraction, 022-311 and 002-3[over ¯]1[over ¯]1, near the iron K edge. Both of the three-wave cases involve the (002) forbidden-weak reflection. The self-normalized three-wave to two-wave (002) diffraction intensity ratio ...
Chen C F - - 2012
Voltage-controlled neuromuscular electrical stimulation has been considered to be safer in noninvasive applications notwithstanding the fact that voltage-controlled devices purportedly generate forces less predictable than their current-controlled equivalents. This prompted us to evaluate relevant electrical parameters to determine whether forces induced by voltage-controlled stimuli were able to match to those ...
Bialynicki-Birula Iwo - - 2012
The uncertainty relation for the photons in three dimensions that overcomes the difficulties caused by the nonexistence of the photon position operator is derived in quantum electrodynamics. The photon energy density plays the role of the probability density in configuration space. It is shown that the measure of the spatial ...
Yang Jieun - - 2012
A facile method for the fabrication of negatively and positively charged rGO field effect transistors (FETs) is proposed, which utilizes electrostatic attraction between electrodes and rGO sheets. Negatively and positively charged rGO sheets are functionalized with carboxylic acid and amine groups, respectively. The FET of amine-functionalized rGO exhibits an n-doping ...
Hofmann D - - 2012
We present a solution scheme for the time-dependent Kohn-Sham self-interaction correction. Based on the generalized optimized effective potential approach, the multiplicative Kohn-Sham potential is constructed in real time and real space for the self-interaction corrected local density approximation. Excitations of different character, including charge-transfer excitations that had been regarded as ...
Cardano Filippo - - 2012
We describe the polarization topology of the vector beams emerging from a patterned birefringent liquid crystal plate with a topological charge q at its center (q-plate). The polarization topological structures for different q-plates and different input polarization states have been studied experimentally by measuring the Stokes parameters point-by-point in the ...
Liang Zixian - - 2012
We show that by coiling up space using curled perforations, a two-dimensional acoustic metamaterial can be constructed to give a frequency dispersive spectrum of extreme constitutive parameters, including double negativity, a density near zero, and a large refractive index. Such an approach has band foldings at the effective medium regime ...
Stone Greg - - 2012
We report changes in the Raman spectra at ferroelectric domain walls in near-stoichiometric LiNbO<sub>3</sub> and stoichiometric LiTaO<sub>3</sub>. We find a decrease of intensity for the regular bulk Raman peaks along with increases of intensity in spectral regions that correspond to phonons, which propagate at an angle with respect to the ...
Schubert A - - 2012
A synchrotron beam has been used to test the spatial resolution of a single-photon-resolving integrating readout-chip coupled to a 320 µm-thick silicon strip sensor with a dedicated readout system. Charge interpolation methods have yielded a spatial resolution of σ(x) ≃ 1.8 µm for a 20 µm-pitch strip.
Choe Jong-Ho - - 2012
We study the scattering properties of an optical slot antenna formed from a narrow rectangular hole in a metal film. We show that slot antennas can be modeled as bound charge oscillators mediating resonant light scattering. A simple closed-form expression for the scattering spectrum of a slot antenna is obtained ...
Aaltonen T - - 2012
In this Letter, we present a precise measurement of the total ZZ production cross section in pp[over ¯] collisions at sqrt[s]=1.96  TeV, using data collected with the CDF II detector corresponding to an integrated luminosity of approximately 6  fb^{-1}. The result is obtained by combining separate measurements in the four-charged (ℓℓℓ^{'}ℓ^{'}) and ...
Houel J - - 2012
We probe local charge fluctuations in a semiconductor via laser spectroscopy on a nearby self-assembled quantum dot. We demonstrate that the quantum dot is sensitive to changes in the local environment at the single-charge level. By controlling the charge state of localized defects, we are able to infer the distance ...
Dadvand Afshin - - 2012
Conductive and emissive: Organic transistors made from a simple styrylanthracene derivative have high charge mobility and high luminescence quantum yields. These properties are attributed to the lack of singlet fission, and challenge the idea that the efficient π interactions required for high mobility always lead to quenching of emission. The ...
Li G - - 2012
We demonstrate trapping and quantum state control of single cesium atoms in a 532 nm wavelength bottle beam trap. The three-dimensional trap is formed by crossing two unit charge vortex beams. Single atoms are loaded with 50% probability directly from a magneto-optical trap. We achieve a trapping lifetime of up ...
Xu Zhenli - - 2012
Electrostatic interactions between multiple colloids in ionic fluids are attracting much attention in studies of biological and soft matter systems. The evaluation of the polarization surface charges due to the spherical dielectric discontinuities poses a challenging problem to highly efficient computer simulations. In this paper, we propose a new method ...
Lodewyck Jerome - - 2012
We report on the observation of a dc Stark frequency shift at the 10-(13) level by comparing two strontium optical lattice clocks. This frequency shift arises from the presence of electric charges trapped on dielectric surfaces placed under vacuum close to the atomic sample. We show that these charges can ...
Bohinc Klemen - - 2012
In the classical mean-field description of the electric double layer, known as the Poisson-Boltzmann model, ions interact exclusively through their Coulomb potential. Ion specificity can arise through solvent-mediated, nonelectrostatic interactions between ions. We employ the Yukawa pair potential to model the presence of nonelectrostatic interactions. The combination of Yukawa and ...
Huntemann N - - 2012
We experimentally investigate an optical frequency standard based on the 467 nm (642 THz) electric-octupole reference transition ^{2}S_{1/2}(F=0)→^{2}F_{7/2}(F=3) in a single trapped ^{171}Yb^{+} ion. The extraordinary features of this transition result from the long natural lifetime and from the 4f^{13}6s^{2} configuration of the upper state. The electric-quadrupole moment of the ^{2}F_{7/2} state ...
Wu Yi Y - - 2012
An analytical study is presented for the steady electrokinetic flow of electrolyte solutions in the fibrous medium constructed by an ordered array of identical, parallel, charged, circular cylinders. The electric field and pressure gradient are applied uniformly in the direction along the axes of the cylinders. The dielectric cylinders may ...
Kharchenko Andriy - - 2012
The orbital trap mass analyzer provides a number of unique analytical features along with inevitable limitations as an electrostatic instrument operating in high space charge regimes resulting in systematic measured frequency errors as an effect of stored ion clouds on the trap field and each other effect of non-ideal machining ...
Jayabharathi Jayaraman - - 2012
Two new heterocyclic imidazole derivatives consists of π-conjugated system attached to a phenanthrimidazole moiety have been synthesized in moderate yield by the condensation of 1,10-phenanthroline-5,6-dione with substituted aromatic aldehydes and 4-methoxyaniline in the presence of ammonium acetate in ethanol medium. The photophysical properties of these imidazole derivatives were studied in ...
Natali Dario - - 2012
A high-mobility organic semiconductor employed as the active material in a field-effect transistor does not guarantee per se that expectations of high performance are fulfilled. This is even truer if a downscaled, short channel is adopted. Only if contacts are able to provide the device with as much charge as ...
Fan Xiaofeng - - 2012
Boron nitride (BN) domains are easily formed in the basal plane of graphene due to phase separation. With first-principles calculations, it is demonstrated theoretically that the band gap of graphene can be opened effectively around K (or K') points by introducing small BN domains. It is also found that random ...
Qu Sanyin - - 2012
Diketopyrrolopyrrole (DPP) pigments have been widely used in inks, paints, and plastics since it was first developed back in the early 1970s. The DPP-based materials were gradually exploited by optical and electrical applications for the excellent fluorescent properties and good charge carrier mobility. In recent years, great interest has been ...
Berti Claudio - - 2012
ABSTRACT: The fast and accurate computation of the electric forces that drive the motion of charged particles at the nanometer scale represents a computational challenge. For this kind of system, where the discrete nature of the charges cannot be neglected, boundary element methods (BEM) represent a better approach than finite ...
Zeuner J M - - 2012
We report on the experimental demonstration of negative coupling constants between defect guides in a waveguide lattice. We find that coupling can only be negative if the defects are negative and an odd number of lattice sites is between the defect guides.
Berger Edmond L - - 2012
A large forward-backward asymmetry is seen in both the top quark rapidity distribution A_{FB}^{t} and in the rapidity distribution of charged leptons A_{FB}^{ℓ} from top quarks produced at the Tevatron. We study the kinematic and dynamic aspects of the relationship of the two observables arising from the spin correlation between ...
Li Xiaoran - - 2012
While it is known that the charge-carrier mobility in organic semiconductors is only weakly dependent on the electric field at low fields, the experimental mobility in organic field-effect transistors using silylethynyl-substituted pentacene is found to be surprisingly field dependent at low source-drain fields. Corroborated by scanning Kelvin probe measurements, we ...
Hu Zixuan - - 2012
We use a finite-difference time-domain (FDTD) approach to describe and control light-induced charge dynamics via two constructs consisting of nanoscale silver cylinders. The charge dynamics is found to be significantly different from the energy dynamics intensively studied in the past in similar systems. It is shown that two-color sources with ...
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