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1.
The variation of the size of two-body objects is investigated, as the separation energy approaches zero, with both long range potentials and short range potentials having a repulsive core. It is shown that long range potentials can also give rise to very extended systems. Except for the l = 0 state, the asymptotic laws differ according to the range of the potential. For short range potentials defined by two and three parameters, their sensitivity to the shape and length is studied. These ideas as well as the transition from the short to the long range regime for the l = 0 case are illustrated using the Kratzer potential. 相似文献
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We analyze the charge transfer statistics through a quantum dot in the Kondo regime, when coupled to an arbitrary number of terminals N. Special attention is paid to current cross correlations between concurring transport channels, which show distinct Hanbury Brown-Twiss antibunching for N>2 reflecting the fermionic nature of charge carriers. While this effect weakens as one moves away from the Kondo fixed point, a new type of correlations between nonconcurring channels emerges which are due entirely to the virtual polarization of the Kondo singlet. As these are not obscured by the background from fixed-point correlations they provide a promising means for extracting information on the parameters of the underlying Fermi-liquid model from the experimental data. 相似文献
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We address the relation between long-range correlations and charge transfer efficiency in aperiodic artificial or genomic DNA sequences. Coherent charge transfer through the highest occupied molecular orbital states of the guanine nucleotide is studied using the transmission approach, and the focus is on how the sequence-dependent backscattering profile can be inferred from correlations between base pairs. 相似文献
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M. Arnold J. Kowalski G. zu Putlitz T. Stehlin F. Träger 《Zeitschrift für Physik A Hadrons and Nuclei》1985,322(2):179-182
Mass-separated beams of clusters with a single, well-defined number of atoms or molecules are indispensable for studies of cluster properties. This paper presents a technique with the potential to generate such a beam which contains neutral clusters of one size only. For this purpose mass-selected cluster ions have been neutralized by charge transfer reactions in metal and sulphur vapors. Relative charge exchange cross sections were measured for different cluster sizes. They reveal pronounced variations of the electronic structure of these particles. Thus, the study of charge transfer processes is introduced as a method to probe the positions of electronic energy levels in neutral clusters. 相似文献
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Yunseok Kim Jiyoon Kim Simon Bühlmann Seungbum Hong Yong Kwan Kim Seung‐Hyun Kim Kwangsoo No 《固体物理学:研究快报》2008,2(2):74-76
We have investigated polarization reversal and charge transfer effects by a grounded tip on 50 nm thick ferroelectric thin films using piezoelectric force microscopy and Kelvin force microscopy. We observed the polarization reversal in the center of written domains, and also identified another mechanism, which is the transfer of screen charges toward the grounded tip. In order to overcome these phenomena, we successfully applied a modified read/write scheme featuring a bias voltage. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Studies on materials with long charge decay times (notably pharmaceutical powders) have shown that the local charge decay time constant comes to increase linearly with time during the progress of charge decay. This is an empirical result. This linear increase provides the basis for calculating the time to 1/e and/or to 10% from much shorter periods of observation than the times to achieve these decays. The approach involves simple numerical processing of the rate of increase in the local charge decay time constant with time and the intercept of this at some selected time. This analysis is useful for assessing and comparing materials that have decay times over say 104 s. 相似文献
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A simple, rapid and sensitive method for the spectrophotometric determination, of bisoprolol was developed. The proposed methods were based on the charge-transfer reactions of bisoprolol, as n-electron donor, with 7,7,8,8-tetracyanoqumodimethane (TCNQ) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as ??-acceptors to give highly colored complexes. The proposed methods were validated according to the ICH guidelines with respect to linearity, limit of detection, limit of quantification, accuracy, precision, recovery and specificity. Beer??s law is obeyed over the concentration ranges of 10?C60 and 10?C80 ??g/mL bisoprolol with TCNQ and DDQ, respectively. The proposed methods were successfully applied to the assay of bisoprolol in pharmaceutical preparations. 相似文献
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Using space-time resolved solutions to relativistic quantum field theory, we analyze the electron-positron creation process from vacuum in the long-time regime in which multiple pairs are produced. We find that for a supercritical potential of finite extension, the time dependence of the production rate of pairs is described by four distinct regimes that have their direct counterparts in the time evolved spatial density of the particles. These regimes include the shape-invariant birth process, an entanglement-induced reduction of interference, a recurrent Pauli suppression of pair production induced by electron-potential scattering, and finally a production halt associated with a population of supercritical and a partial population of subcritical bound states. 相似文献
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WANG Yu-Sa YANG Yan-Ji CHEN Yong LIU Xiao-Yan CUI Wei-Wei XU Yu-Peng LI Cheng-Kui LI Mao-Shun HAN Da-Wei CHEN Tian-Xiang HUO Jia WANG Juan LI Wei HU Wei ZHANG Yi LU Bo YIN Guo-He ZHU Yue ZHANG Zi-Liang 《中国物理C(英文版)》2014,38(6):066001-066001
Charged Coupled Devices (CCDs) have been successfully used in several low energy X-ray astronomical satellites over the past two decades. Their high energy resolution and high spatial resolution make them a perfect tool for low energy astronomy, such as observing the formation of galaxy clusters and the environment around black holes. The Low Energy X-ray Telescope (LE) group is developing a Swept Charge Device (SCD) for the Hard X-ray Modulation Telescope (HXMT) satellite. A SCD is a special low energy X-ray CCD, which can be read out a thousand times faster than traditional CCDs, simultaneously keeping excellent energy resolution. A test method for measuring the charge transfer efficiency (CTE) of a prototype SCD has been set up. Studies of the charge transfer inefficiency (CTI) with a proton-irradiated SCD have been performed at a range of operating temperatures. The SCD is irradiated by 3×108cm-2 10 MeV protons. 相似文献
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M. A. Kumakhov 《Technical Physics》2014,59(7):1091-1093
It is suggested that the effect of multiple contactless rotation of electrons in an electrified ring, which has been recently discovered by our group, be used for energy transfer over long distances. In experiments with the ring, electrons travel very long distances, ≥107 km. Electron losses due to radiation and losses in a residual gas are analyzed. It is shown that these losses are much lower than 10?4 % over a distance of ≥104 km. Analysis is performed with regard to the complicated profile of the track. The electrical power that can be transmitted through such a channel is estimated. It exceeds 1013 W at a channel diameter of several millimeters. If channels have the form of a solenoid or toroid, high magnetic fields arise in them, which may find different applications including magnetic plasma confinement. 相似文献
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The process of exciting atoms and atomic nuclei by relativistic electrons and positrons bound in a one-dimensional potential is investigated theoretically. It is shown that a pole corresponding to the emergence of a virtual photon on a bulk surface occurs in the matrix interaction element under definite kinematic relationships. It is obtained that the probability of the excitation process depends on the lifetime of the level being excited, the virtual photon, and the charged particle in a definite energetic state. An estimate of the magnitude of the excitation section of low-lying nuclear states yields a value exceeding by several, orders the section obtained for charged particles in the absence of a binding potential.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 7–11, May, 1987. 相似文献
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《Physics letters. A》2019,383(17):2004-2010
In this work we consider bipartite noisy bound entangled states with positive partial transpose, that is, such a state can be written as a convex combination of an edge state and a separable state. In particular, we present schemes to construct distinct classes of noisy bound entangled states which satisfy the range criterion. As a consequence of the present study we also identify noisy bound entangled states which do not satisfy the range criterion. All of the present states are constituted by exploring different types of product bases. 相似文献
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一个无序自旋玻璃系统可能有许许多多能量最小态或基态构型.有些格点的自旋可能在所有这些基态中都只取同一个值(这种情况称为自旋凝固).也有另外一种情况出现,即某些格点在一部分基态中自旋取向上而在其余的基态中自旋向下;这样的格点称为未凝固的格点.本文的工作表明,2个或多个未凝固的格点,虽然每个格点的自旋都随着基态的不同而改变,但是有可能某一些特定的自旋取向组合不会出现于任何一基态构型中.这种现象称为长程阻错.本文提出一个新的长程阻错序参量R来定量刻划这种现象,并将这一统计物理理论用于图的最小覆盖和K—SAT等组合优化问题. 相似文献
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J. Linares H. Spiering F. Varret 《The European Physical Journal B - Condensed Matter and Complex Systems》1999,10(2):271-275
It is well-known that 1D systems with only nearest neighbour interaction exhibit no phase transition. It is shown that the
presence of a small long range interaction treated by the mean field approximation in addition to strong nearest neighbour
interaction gives rise to hysteresis curves of large width. This situation is believed to exist in spin crossover systems
where by the deformation of the spin changing molecules, an elastic coupling leads to a long range interaction, and strong
bonding between the molecules in a chain compound leads to large values for nearest neighbour interaction constants. For this
interaction scheme an analytical solution has been derived and the interplay between these two types of interaction is discussed
on the basis of experimental data of the chain compound which exhibits a very large hysteresis of 50 K above RT at 370 K. The width and shape of the hysteresis loop depend on the
balance between long and short range interaction. For short range interaction energies much larger than the transition temperature
the hysteresis width is determined by the long range interaction alone.
Received 26 November 1998 相似文献