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801.
基于密度泛函理论结合对称性破损态方法(DFT-BS),相对论效应选择DKH2,运用不同的密度泛函和基组对GdNi双核配合物[Ni(3-MeOsaltn)(MeOH)(ac)Gd(hfac)_2]的磁性质进行研究。结果显示,B3LYP泛函计算的结果与实验数据非常吻合,能够准确描述Gd Ni双核配合物的磁性质。磁轨道和自旋布居分析表明,顺磁中心Gd~Ⅲ主要是自旋极化作用,顺磁中心Ni~Ⅱ主要是自旋离域作用。顺磁中心Gd~Ⅲ、Ni~Ⅱ与桥联氧原子之间存在较强的轨道相互作用。磁轨道主要由顺磁中心Ni~Ⅱ的3dz2和3dx2-y2轨道、酚氧桥联配体中氧原子的2pz轨道、醋酸桥中氧原子的2pz轨道和顺磁中心Gd~Ⅲ的4fxyz、4fz2x轨道组成。随着Gd-O-Ni键角的增大,顺磁中心HS态和BS态自旋密度的平方差随之减小,反铁磁性相互作用的贡献减小,配合物磁耦合常数增大。 相似文献
802.
Fractal fluctuations in cardiac time series 总被引:1,自引:0,他引:1
B. J. West R. Zhang A. W. Sanders S. Miniyar J. H. Zuckerman B. D. Levine 《Physica A》1999,270(3-4):552-566
Human heart rate, controlled by complex feedback mechanisms, is a vital index of systematic circulation. However, it has been shown that beat-to-beat values of heart rate fluctuate continually over a wide range of time scales. Herein we use the relative dispersion, the ratio of the standard deviation to the mean, to show, by systematically aggregating the data, that the correlation in the beat-to-beat cardiac time series is a modulated inverse power law. This scaling property indicates the existence of long-time memory in the underlying cardiac control process and supports the conclusion that heart rate variability is a temporal fractal. We argue that the cardiac control system has allometric properties that enable it to respond to a dynamical environment through scaling. 相似文献
803.
B. Borderie F. Gulminelli M.F. Rivet L. Tassan-Got M. Assenard G. Auger F. Bocage R. Bougault R. Brou Ph. Buchet J. Colin R. Dayras A. Demeyer J.D. Frankland E. Galichet E. Genouin-Duhamel E. Gerlic M. Germain D. Guinet P. Lautesse J.L. Laville J.F. Lecolley T. Lefort R. Legrain N. Le Neindre M. Louvel A.M. Maskay L. Nalpas A.D. Nguyen M. Parlog E. Plagnol A. Rahmani T. Reposeur E. Rosato F. Saint-Laurent S. Salou J.C. Steckmeyer M. Stern G. Tabacaru B. Tamain O. Tirel D. Vintache C. Volant 《The European Physical Journal A - Hadrons and Nuclei》1999,6(2):197-202
Vaporized sources produced in collisions between 36Ar and 58Ni at 95 MeV per nucleon have been detected with the multidetector INDRA. Complete information concerning the deexcitation
properties of quasi-projectiles, including second moments of chemical composition, is compared to a quantum statistical model
describing a gas of fermions and bosons in thermal and chemical equilibrium. Inclusions in the calculation of all known discrete
levels of nuclear species which deexcite into light particles and of a final state excluded volume interaction are found decisive
to very well reproduce the experimental data, which strongly supports that thermodynamical equilibrium was achieved at freeze-out
for such sources.
Received: 6 April 1999 相似文献
804.
Charge-dependent correlations from both background and charge separation contribute to experimental observables in heavy-ion collisions. In this paper, we use stochastic hydrodynamics to study background charge asymmetry due to fluctuations. Using the rapidity-dependent correlation and a simple ansatz for particle distributions, we find a fluctuation-induced correlation to provide a type of background F -correlation. Experimental data for Au+Au collisions at $\sqrt{{s}_{\mathrm{NN}}}=200\,\mathrm{GeV}$ are compared. We also make predictions for F -correlations in isobar collisions. Combining this with our previous chiral magnetic effect results, we obtain δ -correlations for collisions in the three types of system. Computations from our model show an almost identical background with less than 2% difference for isobars, but roughly 10% difference for their charge separations. In combination with our earlier works, we provide a consistent method of calculating both the chiral magnetic effect and the charged background in the context of stochastic hydrodynamics. 相似文献
805.
A summary of selected thermophysical properties of refractory metallic carbides is reported with a critical evaluation of the data. A target of this work was to collect a wide and selected set of data spanning from physical and physico-chemical parameters to more specialistic physico-mechanical items of informations, all useful for technological applications. A second target was to obtain a comprehensive view of the matter concerning cubic carbides. On the collected data the authors have carried out a number of elaborations, correlation analyses, search for trends and graphic presentations in order to assess the validity of numerical figures inside a more general context and to extract some physical and/or physico-chemical meaning also through the aid of proposed equations. 相似文献
806.
Peter Fulde Patrick Unger Jun-Ichi Igarashi 《International journal of quantum chemistry》1997,63(3):645-653
Until now, solids with strongly correlated electrons can be treated only by model Hamiltonians. Even then a calculation of spectral densities is not simple, because the strong Coulomb interactions prevent us from treating correlations perturbatively. We show that projection and partitioning techniques are a very valuable tool here. The method is applied to computations of the density of states of transition metals, in particular, Ni. Here, the band narrowing and the sattlite peak at 6 eV due to correlations are reproduced. A second application concerns the spectral density of doped and undoped Cu(SINGLE BOND)O planes which are part of the high-Tc superconducting materials. © 1997 John Wiley & Sons, Inc. J Quant Chem 63: 645–653, 1997 相似文献
807.
Dr. Julia Neumann Dr. Sang Soo Lee Eric J. Zhao Dr. Paul Fenter 《Chemphyschem》2023,24(22):e202300742
The front cover artwork is provided by Argonne National Laboratory. The image shows the arrangement of correlated cations and anions at a charged solid surface in contact with highly concentrated electrolyte solutions. Read the full text of the Research Article at 10.1002/cphc.202300545 . 相似文献
808.