Investigation of optoelectronic properties of pure and Co substituted α-Al_2O_3 by Hubbard and modified Becke–Johnson exchange potentials

Advanced GGA ＋ U（Hubbard） and modified Becke–Johnson（mBJ） techniques are used for the calculation of the structural, electronic, and optical parameters of α-Al2-x CoxO3（x = 0.0, 0.167） compounds. The direct band gaps calculated by GGA and m BJ for pure alumina are 6.3 eV and 8.5 eV, respectively. The m BJ approximation provides results very close to the experimental one（8.7 eV）. The substitution of Al with Co reduces the band gap of alumina. The wide and direct band gap of the doped alumina predicts that it can efficiently be used in optoelectronic devices. The optical properties of the compounds like dielectric functions and energy loss function are also calculated. The rhombohedral structure of theα-Al2-x CoxO3（x = 0.0, 0.167） compounds reveal the birefringence properties.

Bottomonium Spectrum and Decays with One Gluon Exchange Potential

The phenomenological non-relativistic quark model （NRQM） has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. The Hamiltonian used in the investigation has kinetic energy, confinement potentiM and one gluon exchange potential （OGEP）. An overall agreement is obtained with the experimental masses and decay widths.

The Effects of Na^+/Ca^(2+) exchange (NCX) on the Repolarization of Canine Ventricular Myocyte-Potential Arrhythmogenic Effect of NCX during a Mis-matched Repolarization and Relaxation Xiamen Zhongshan Hospital, Xiamen Medical College, Xiamen University

Objective Background and Objects: Naturally occurring temporal variability of action potentialduration (APD) in isolated myocytes has been noted. Most of the studies have beenfocusing on analyzes of the differences in ionic channels and currents among theepicardial-, mid-myocardial-(M) and endocardial myocytes, and the rate-dependent (adaptation) characteristics of APD. We have found that the change in APD during achange in frequency of stimulation mostly reflects a change in rate of repolarization at distinct membrane potential levels. We assumed that in the myocytes, there is balancing mechanism, which is constantly adjusting the various ionic currents accommodating to the changing conditions. This intrinsic ability of adaptation is important and may offer some of the consequences of the transmural heterogeneity in adaptation of APD. This adaptive behaviors maybe equally important in maintaining the normal electrophysiological properties and in induction of arrhythmia in a case of error in normal adaptation. Though most studies of Na +/Ca 2+ exchange (NCX) has been emphasized on its reverse activaty during pathyological condition. Our hypothesis is that reverse activaty of NCX also plays an important role in adjusting the repolarization of AP during a physiological condition. A mismatch between action potential (AP) repolarization and relaxation of the contraction can be caused by intracellular Ca 2+ transport abnormalities. Ca 2+ influx via reverse activation of NCX can load the sarcoplasmic recticulum (SR), which has arrhythmogenic effect.Methods We studied the single myocytes from the left ventricle of adult mongrel dogs. During the cell separation, collagenase was perfused through LAD by Langandorff system. We use the patch-clamp system to determinded AP in current clamp mode. Myocyte contraction was imaged by a video camera, shortening of unloaded myocytes was detected by a video edge motion detector, using changes in light intensity at the edges of the myocyte. Results From 60 consecutive recorded APs at a constant 1.0 Hz stimulation under steady state conditions we found there is a variance in the repolarization between 10mV and-40mV. We also found the variance in the APD during the rate adaptation range of repolarization. Fluctuation in the transient may contribute to the APD variability. To test thishypothesis we block the transient by intracellular dialysis with 10 mM EGTA(n=19), this caused a significant reduction in the coefficient variability (CV=SD/mean APD%) from 2.3± 0.8 to 1.3± 0.3 P< 0.01. During a rate change of the stimulation from 0.6 Hz to 1.0 Hz. The AP duration increased from 278±8 msec to 320±9 msec, Mean+SD, n=5, 50 APs, P< 0.05. contraction is accompanied by an after-contraction(A-CON). The relaxation of contraction precedes the repolarization of the AP. We assumed that the enhancement of repolarization and the production of after-contraction can be possibly induced by reverse mode of NCX. Reducing [Na +] o by substitution of 40mM Na + with Li + favors NCX activating the reverse mode, which significantly decreased the dome of the AP from 4.8± 0.3 to -10.6± 1.2mV, P< 0.05, and increased the APD from 330±13 to 368±14 msec. P< 0.05.Conclusions Intracellular calcium transient most likely contributes to the beat-to-beat variance of action potential duration in canine ventricular myocyte. And it attributes to the voltage-dependent switch of NCX mode. Calcium concentration is high inmyocytes during the repolarization, and high intracellular Ca 2+ activates NCX in such a manner, that it generates an inward (positive, depolarizing) current. This current works against the repolarization, it is prolonging it, with other words it increases the duration of the action potential. The magnitude of calcium concentration during repolarization is very much dependent on calcium transport in the SR. The calcium transport in the SR is subject to adrenergic actions, and other physiologic and pathologic regulators. Under pathologic conditions

Responses of leaf water potential and gas exchange to the precipitation manipulation in two shrubs on the Chinese Loess Plateau

Regulation of leaf gas exchange plays an important role in the survival of trees and shrubs under future climate change. However, the responses of leaf water potential and gas exchange of shrubs in semi-arid areas to the precipitation alteration are not clear. Here, we conducted a manipulated experiment with three levels of precipitation, i.e., a control with ambient precipitation, 50% above ambient precipitation(irrigation treatment), and 50% below ambient precipitation(drought treatment), with two common shrubs, Salix psammophila C. Wang & C. Y. Yang(isohydric plant, maintaining a constant leaf water potential by stomatal regulation) and Caragana korshinskii Kom.(anisohydric plant, having more variable leaf water potential), on the Chinese Loess Plateau in 2014 and 2015. We measured the seasonal variations of predawn and midday leaf water potential(Ψpd and Ψmd), two parameters of gas exchange, i.e., light-saturated assimilation(An) and stomatal conductance(gs), and other foliar and canopy traits. The isohydric S. psammophila had a similar An and a higher gs than the anisohydric C. korshinskii under drought treatment in 2015, inconsistent with the view that photosynthetic capacity of anisohydric plants is higher than isohydric plants under severe drought. The two shrubs differently responded to precipitation manipulation. Ψpd, An and gs were higher under irrigation treatment than control for S. psammophila, and these three variables and Ψmd were significantly higher under irrigation treatment and lower under drought treatment than control for C. korshinskii. Leaf water potential and gas exchange responded to manipulated precipitation more strongly for C. korshinskii than for S. psammophila. However, precipitation manipulation did not alter the sensitivity of leaf gas exchange to vapor-pressure deficit and soil moisture in these two shrubs. Acclimation to long-term changes in soil moisture in these two shrubs was primarily attributed to the changes in leaf or canopy structure rather than leaf gas exchange. These findings will be useful for modeling canopy water-carbon exchange and elucidating the adaptive strategies of these two shrubs to future changes in precipitation.

Didactics of Languages:Implementing Dynamic Exchanges and Enhancing the Potential of Creativity in a Mentoring Context

Group dynamics is applied not only in the professional life but also in the educational framework becoming one of the tools of group therapy aiming at reducing conflicts and tensions.Under this perspective it would be interesting to study the dynamic exchanges that take place within the interrelations of the facilitator with his target group aiming at further exploiting the cognitive and affective resources of the participants in order to manage their potential more effectively and to accompany them in any training situation.From an actional perspective the adoption of collaborative tasks promotes cooperation and problem solving in a mentoring context,where the members invest in the realization of a meaningful action project in order to implement creative tasks and cultivate transversal skills using digital technology.

Donnan Electric Potential Dependence of Intraparticle Diffusion of Malachite Green in Single Cation Exchange Resin Particles: A Laser Trapping-Microspectroscopy Study

A laser trapping-microspectroscopy technique combined with excitation energy transfer from a fluorescent cationic dye (Rhodamine B, RB+) to a non-fluorescent cationic dye (Malachite Green, MG+) was employed to study pH effects on the diffusion coefficients of MG+ (D(MG+)) in single cation-exchange resin microparticles with the diameters of 16 μm. When RB+-pre-adsorbed resin particles were soaked in an aqueous MG+ solution, the RB+ fluorescence was quenched gradually with the soaking time. The time course of the quenching efficiency of RB+ by MG+ was then used to evaluate the D(MG+) value in the particle. The D(MG+) value increased from 1.1 × 10-11 to 4.3 × 10-11 cm2.s–1 on going the solu- tion pH value from 9 to 4. The results were explained reasonably by a Donnan electric potential model.

Structure and Properties of Hydrotalcite Using Electrostatic Potential Energy Model

The electrostatic potential energy model of hydrotalcites was based on the theory of crystallography. The anionic potential energy of MgAl-hydrotalcites, with 20 layers and 2107 anions per layer, was calculated, and the anionic stability of the hydrotalcites was investigated. The charge density of the layer and the distance between the adjacent anions varied with the molar ratio of Al^3＋/（Mg^2＋ ＋ Al^3＋）. Anionic potential energy depended on the charge and size of the anions. Calculation results remained consistent with thermal stability and the ion exchange ability reported. This model is able to predict anionic stability of the hydrotalcites.

Study on the permselectivity of ion exchange membrane

Ion exchange membranes with high permselectivity (the character of separatingcations from anions or anions from cations) and high selectivity (the character of separatingcations or anions of different valencies) are important for electrodialysis process. The Donnanequilibrium theory, based on the equilibrium of ions and no electric field, can not exactly explainthe permselectivity of ion exchange membrane for ED process, since it is impossible to set up a ionexchange equilibrium between membrane and solution and to neglect the influence of electricaldriving force on ions during ED process. A novel model named 'anti-electric potential' isestablished to interpret the permselectivity of ion exchange membrane, according to thedetermination of electric potential between membranes and the variation of elements content insolutions and membranes. The results of experiment prove that the 'anti-electric potential' reallyexists within membranes. As for the selectivity, the results reveal that electric potential andhydration energy have great influence on the concentration and mobility of ions in membranes.

Effect of Interaction Potential on Laser-assisted e-Ar Scattering

The interaction potentials between electron and atom play an important role in electron- atom scattering. Using three potential models, the absolute differential cross section has been calculated by the second Born approximation theory. Results show that these model potentials are successful in the laser-assisted e-Ar scattering system. The influence of static potential, exchange potential and polarization potential on the absolute differential cross section is also analyzed and discussed.

Oscillatory Behavior of In-medium Interparticle Potential in Hot Gauge System with Scalar Bound States

We investigate the in-medium interparticle potential of hot gauge system with bound states by employing the QED and scalar QED coupling. At the finite temperature an oscillatory behavior of the potential has been found as well as its variation in terms of different free parameters. We expect the competition among the parameters will lead to an appropriate interparticle potential, which could be extended to discuss the fluid properties of QGP with scalar bound states.

NUCLEON-NUCLEON INTERACTION WITH A FLAT BOTTOM LINEAR CONFINEMENT POTENTIAL IN THE QUARK MODEL

Nucleon-nucleon interaction is studied in the non-relativistic quark model with a flat bottom linear confinement potential.The results are consistent with the calculated ones from the lattice quantum chromodynamics.The quark-quark interaction also consists of those caused by the one gluon exchange and the one pion exchange.The phenomenological sigma meson exchange between two nucleons is also included to fit the S-wave N-N scattering data.The calculated NN channel S-wave phase shifts show that the flat bottom linear confinement potential can provide part of the medium range attraction.

A potential game-based outsourcing computation framework for multiple calculators

Outsourcing computation enables a computationally weak client to outsource the computation of a function f to a more powerful but untrusted server.The traditional outsourcing computation model forbids communication between players,but it has little effect.Based on the game theory,this paper establishes an outsourcing computation model which is more in line with the actual scene.Firstly,we construct a structural mapping relationship between security outsourcing computation and the optimization problem.Secondly,by designing the individual potential function and the global potential function,the individual goal is consistent with the global goal to ensure the correctness of the calculation results.Finally,in the information exchange environment between calculators,we construct a Zero-determinant strategy to ensure that the calculator chooses the strategy according to the predetermined target.

On the Mechanism of Nucleon-Nucleon Attraction by Pion Exchange

A formula is derived for the central nucleon-nucleon potential, based on an analysis of the physical origin of the nucleon-nucleon attraction by pion exchange. The decrease of the dynamical mass of the interaction field, exchanged pion in this case, is the principal mechanism responsible for the nuclear attraction in a similar way that the decrease of the kinetic energy of the exchange electron in the diatomic molecule is directly responsible for the covalent molecular attraction. The minimum value of this central nucleon-nucleon potential and the position of the minimum are similar with the values reported in literature for a potential calculated by lattice QCD, which shares the features of the phenomenological nucleon-nucleon potentials. The Schrodinger equation with this central nucleon-nucleon potential was solved numerically for different values of the pion mass. The binding energy increases with the decrease of the pion mass. For masses higher than the real pion mass the nucleon-nucleon system is unbound. We discuss on the two pion exchange and hard core repulsion. The minimum value of the potential for two pion exchange is comparable with the minimum value of the CD Bonn potential. For a hard core radius of 0.5 fm the binding energy is equal to the deuteron binding energy.

Exchange-Correlation Functional Comparison of Electronic Energies in Atoms Using a Grid Basis

Calculation of total energies of the electronic ground states of atoms forms the basis for the frozen-core pseudopotentials used in atomistic calculations of much larger scale. Reference values for these energies provide a benchmark for the validation of new software to calculate such potentials. In addition, basic atomic-scale electronic properties such as the (first) ionization energy provide a simple check on the approximation used in the calculation method. We present a comparison of the total energies and ionization energies of atoms Z = 1 - 92 calculated in density functional theory with several levels of exchange-correlation functional and the Hartree-Fock method, comparing ionization energies to experiment. We also investigate the role of relativistic treatment on these energies.

A Study of Superconducting La₂CuO₄via Generalized BCS Equations Incorporating Chemical Potential

We address the Tc (s) and multiple gaps of La2CuO4 (LCO) via generalized BCS equations incorporating chemical potential. Appealing to the structure of the unit cell of LCO, which comprises sub- lattices with LaO and OLa layers and brings into play two Debye temperatures, the concept of itinerancy of electrons, and an insight provided by Tacon et al.’s recent experimental work concerned with YBa2Cu3O6.6 which reveals that very large electron-phonon coupling can occur in a very narrow region of phonon wavelengths, we are enabled to account for all values of its gap-to-Tc ratio (2Δ0/kBTc), i.e., 4.3, 7.1, ≈8 and 9.3, which were reported by Bednorz and Müller in their Nobel lecture. Our study predicts carrier concentrations corresponding to these gap values to lie in the range 1.3 × 1021 - 5.6 × 1021 cm-3, and values of 0.27 - 0.29 and 1.12 for the gap-to-Tc ratios of the smaller gaps.

The Pursuit of Fallacy in Density Functional Theory: The Quest for Exchange and Correlation, the Rigorous Treatment of Exchange in the Kohn-Sham Formalism and the Continuing Search for Correlation

As pointed out in the paper preceding this one, in the case of functionals whose independent variable must obey conditions of integral normalization, conventional functional differentiation, defined in terms of an arbitrary test function, is generally inapplicable and functional derivatives with respect to the density must be evaluated through the alternative and widely used limiting procedure based on the Dirac delta function. This leads to the determination of the rate of change of the dependent variable with respect to its independent variable at each isolated pair, , that may not be part of a functional (a set of ordered pairs). This extends the concept of functional derivative to expectation values of operators with respect to wave functions leading to a density even if the wave functions (and expectation values) do not form functionals. This new formulation of functional differentiation forms the basis for the study of the mathematical integrity of a number of concepts in density functional theory (DFT) such as the existence of a universal functional of the density, of orbital-free density functional theory, the derivative discontinuity of the exchange and correlation functional and the extension of DFT to open systems characterized by densities with fractional normalization. It is shown that no universal functional exists but, rather, a universal process based only on the density and independent of the possible existence of a potential, leads to unique functionals of the density determined through the minimization procedure of the constrained search. The mathematical integrity of two methodologies proposed for the treatment of the Coulomb interaction, the self-interaction free method and the optimized effective potential method is examined and the methodologies are compared in terms of numerical calculations. As emerges from this analysis, the optimized effective potential method is found to be numerically approximate but formally invalid, contrary to the rigorously exact results of the self-interaction-free method.

Topology-like dynamical behavior of magnetization reversal in exchange-bias systems

In an exchange-bias system, the barriers with intrinsic potential energy may be asymmetric due to unidirectional anisotropy. Based on the Stoner–Wohlfarth model, we show that the asymmetric barriers may lead to four kinds of dynamical process underlying the hysteresis-loop measurement. These kinds of dynamical processes are different in a topology-like property, which can be controlled by the orientation of the external field. In our study, a new analysis approach has been proposed to reveal the dynamical behaviors of magnetization reversal. With this approach, coercivity, exchange-bias field, and asymmetry of hysteresis loops can be quantitatively obtained.

Scaling for Experimental Inner-Sphere Reorganization Energy of Hydrated Ions via Accurate Potential Function

Reported here are several new calculation methods for the inner-sphere reorganization energy of hydrated metal ions involved in electron transfer processes.It is based on the self-exchange model of reorganization and utilizes the more exact potential functions between central metal ion and the inner-sphere ligands.The parameters involved are determined via the spectroscopic and thermodynamic data.The predictions of the inner-sphere reorganization energies from those models agree well with the photoemission experimental results.

Drought Tolerance and Recovery of the Sedge Carex planostachys (Cyperaceae) from Central Texas Woodlands

Carex planostachys Kunze (Cyperaceae, Cedar sedge) is an herbaceous species in a genus commonly inhabiting mesic or hydric habitats. Carex planostachys is found in arid and semi-arid Juniperus woodlands. Arid conditions impose survival challenges to plants in dry areas. Some plants have plasticity responses to soil water content and continued normal though reduced functions through droughts, but most herbaceous plants do not survive. Limited previous studies have suggested C. planostachys is tolerant of drought. Physiological responses of C. planostachys from Juniperus woodlands was examined is this study to determine how long plants could survive without water and if they are capable of recovery from very negative water potentials beyond what is considered the permanent wilting point for most herbaceous plants. Plants were placed in pots in partial shade in this experiment. Water loss from the soil with plants was an inverse 2nd order polynomial function with soil water decreasing from 32% to 8% by day 28 of the study. Leaf water potential was also an inverse 2nd order polynomial function but did not decline significantly until 14 days without watering. Leaf water potential was −10.0 MPa after 35 days without watering. Non-watered plants Anet, (photosynthetic rate) was significantly lower compared to the water treatment by day 21 as was stomatal conductance and transpiration. When non-watered plants were watered after 21, 28 or 35 days, full recovery of physiological responses occurred within 7 days. The length of time that C. planostachys was able to withstand drought was greater than the annual trends in lack of precipitation during springtime in this area. Carex planostachys can photosynthesize at water stress between −8 and −10 MPa. Carex planostachys drought and shade tolerance enables it to occupy an understory niche devoid of other herbaceous plants.