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排序方式: 共有810条查询结果,搜索用时 281 毫秒
731.
B. Rache Salles F. Vidal V.H. Etgens R. Breitwieser M. Marangolo M. Eddrief 《Physica B: Condensed Matter》2009,404(18):2684-2688
This paper reviews some recent works performed on MnAs/GaAs thin films and other related structures grown by molecular beam epitaxy. The impact of epitaxy on the magneto-structural properties of MnAs and possible applications of MnAs epilayers are discussed. A brief account of recent results obtained on the magneto-transport in MnAs/GaAs/MnAs magnetic tunnel junctions is also given, highlighting several appealing and promising properties of this system for spintronics applications. 相似文献
732.
Jordan Hristov 《中国颗粒学报》2009,(3)
The article presents an effort to create dimensionless scaling correlations of the overall bed porosity in the case of magnetically assisted fluidization in a tapered vessel with external transverse magnetic field. This is a stand of portion of new branch in the magnetically assisted fluidization recently created concerning employment of tapered vessels. Dimensional analysis based on "pressure transform" of the initial set of variables and involving the magnetic granular Bond number has been applied to deve... 相似文献
733.
Assane Lo 《Journal of statistical physics》2008,132(2):355-396
The aim of this paper is to apply direct methods to the study of integrals that appear naturally in Statistical Mechanics
and Euclidean Field Theory. We provide weighted estimates leading to the exponential decay of the two-point correlation functions
for certain classical convex unbounded models. The methods involve the study of the solutions of the Witten Laplacian equations
associated with the Hamiltonian of the system. 相似文献
734.
We consider invertible discrete-time dynamical systems having a hyperbolic product structure in some region of the phase space
with infinitely many branches and variable return time. We show that the decay of correlations of the SRB measure associated
to that hyperbolic structure is related to the tail of the recurrence times. We also give sufficient conditions for the validity
of the Central Limit Theorem. This extends previous results by Young in (Ann. Math. 147: 585–650, [1998]; Israel J. Math. 110: 153–188, [1999]).
Work carried out at the Federal University of Bahia, University of Porto and IMPA. J.F.A. was partially supported by FCT through
CMUP and POCI/MAT/61237/2004. V.P. was partially supported by PADCT/CNPq and POCI/MAT/61237/2004. 相似文献
735.
O.V. Danylenko O.V. Dolgov M.L. Kulic V. Oudovenko 《The European Physical Journal B - Condensed Matter and Complex Systems》1999,9(2):201-206
By assuming that the superconducting pairing is due to the forward E-P scattering (FEP pairing) it is shown that the critical temperature of clean systems depends linearly on the E-P coupling constant and the isotope effect is very small. Impurities with the pronounced forward scattering (FS impurities) change analytical properties of the quasiparticle Green's function substantially compared to the case of the
isotropic scattering. The FS impurities are pair-breaking and affect in the same way s- and d-wave
FEP pairing making in the dirty limit.The usual isotropic impurity scattering is pair-weakening for s-wave and pair-breaking for the d-wave
FEP pairing.
Received 1st July 1998 相似文献
736.
M. K. Kirejczyk 《The European Physical Journal A - Hadrons and Nuclei》2009,41(2):141-143
The -variable, a measure of statistical correlation of particle momenta, introduced by Mrówczyński and Gaździcki, has been calculated
for the events simulated with a simple thermal toy model. It is shown that mixing two thermal sources of unequal temperature
can result in negative values of . 相似文献
737.
Aparajita Dey S. Bhattacharya C. Bhattacharya K. Banerjee T. K. Rana S. Kundu S. R. Banerjee S. Mukhopadhyay D. Gupta R. Saha 《The European Physical Journal A - Hadrons and Nuclei》2009,41(1):39-51
Inclusive energy distributions for light charged particles (p , d , t and have been measured in the 20Ne (158, 170, 180, 200 MeV) + 12C
reactionsintheangularrange$10°$ - - $50°$.Exclusivelight-charged-particleenergydistributionmeasurementswerealsodoneforthesamesystemat158 MeVbombardingenergybyin - planelightchargedparticle - - fragmentcoincidence.Pre - equilibriumcomponentshavebeenseparatedoutfromprotonenergyspectrausingthemovingsourcemodelconsideringtwosources.ThedatahavebeencomparedwiththepredictionsofthestatisticalmodelcodeCASCADE.Ithasbeenobservedthatsignificantdeformationeffectswereneededtobeintroducedinthecompoundnucleusinordertoexplaintheshapeoftheevaporated$d$,$t$energyspectra.Forprotons, evaporatedenergyspectrawereratherinsensitivetonucleardeformation, thoughangulardistributionscouldnotbeexplainedwithoutdeformation.Thedecaysequenceofthehot$32S$nucleushasbeeninvestigatedthroughexclusivelight - - charged - particlemeasurementsusingthe$20Ne$$(158 MeV) + $12C
reaction. Information on the sequential decay chain has been extracted through a comparison of the experimental data with
the predictions of the statistical model. It is observed from the present analysis that exclusive light-charged-particle data
may be used as a powerful tool to probe the decay sequence of hot light compound systems. 相似文献
738.
We calculate the conductance through Aharonov-Bohm chain and ladder rings pierced by a magnetic flux which couples with the charge degrees of freedom. The system is weakly coupled to two leads and contains strongly interacting electrons modeled by the prototypical t-J and Hubbard models. For a wide range of parameters we observe characteristic dips in the conductance as a function of magnetic flux which are a signature of spin and charge separation. We also show how the dips evolve when the parameters of the models depart from the ideal case of total spin-charge separation. The ladder ring can be mapped onto an effective model for large anisotropy which can be easily analyzed. These results open the possibility of observing this peculiar many-body phenomenon in anisotropic ladder systems and in real nanoscopic devices. 相似文献
739.
基于密度泛函理论结合对称性破损态方法,选择不同的泛函方法和基组研究吡唑/草酸根混合配位的非对称双核铜配合物的磁学性质。结果表明,在B3LYP/def2-TZVP水平计算的磁耦合常数为-127.24cm~(-1),与实验值-129cm~(-1)基本吻合,可准确描述吡唑/草酸根混合配位的非对称双核铜配合物的磁学性质。磁轨道和自旋布居分析表明,顺磁中心Cu(Ⅱ)与桥联配体草酸根离子间存在较强的轨道相互作用,其磁轨道主要由顺磁中心Cu(Ⅱ)的3d_x2_(-y)2轨道、桥联配体草酸根离子的π键组成,顺磁中心Cu(Ⅱ)主要是自旋离域机理。配合物磁性与结构关系的研究表明,随着结构参数τ的增加,顺磁中心HS态和BS态自旋密度的平方差和自然磁轨道间重叠积分的平方随之增大,反铁磁性相互作用的贡献增大,配合物磁耦合常数J值减小。 相似文献
740.
Wen‐Yang Sun Dong Wang Bao‐Long Fang Zhi‐Yong Ding Huan Yang Fei Ming Liu Ye 《Annalen der Physik》2019,531(2)
Quantum resources play crucial roles for displaying superiority in many quantum communication and computation tasks. To reveal the intrinsic relations hidden in these quantum resources, many efforts have been made in recent years. In this work, the correlations of the tripartite W‐type states based on bipartite quantum resources are investigated. The inter‐relations among the degree of coherence, concurrence, Bell nonlocality, and purity are presented. Considering Bell nonlocal and Bell local (satisfied the Clauser–Horne–Shimony–Holt inequality) states for the two‐qubit subsystems derived from the tripartite W‐type states, exact lower and upper boundaries of the degree of coherence versus concurrence are obtained. Interestingly, exact relation among the degree of coherence, concurrence, and purity is obtained. Moreover, coherence is also closely related to entanglement in two specific scenarios: the tripartite W‐type state under decoherence and a practical system for a renormalized spin‐1/2 Heisenberg model. 相似文献