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1.
The g-factors of some members of the ground state band and of the 2+ state in the %-vibrational band have been measured in 160,162,164Dy using the Coulomb Excitation Transient Field technique, induced by 58Ni projectiles at 230, 210 and 217 MeV, respectively. The g-factors in the ground state band are consistent with a constant value, while that of the 2+% states is about 20% larger in average than those in the ground state band. Results are discussed in the frame of the systematics in this nuclear region.  相似文献   

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Pion production in heavy-ion collisions is considered within the hydrodynamic approach. It is shown that consideration of pion production as a result of Δ-resonance decay (Δ → N + π) leads to hardening of the high-energy “tails” of subthreshold pions.  相似文献   

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Increasing the concentration of indium atoms and hydrogen was found in the α-phase of the foil of a Pd-In alloy (with 5.3 and 5.0 at % In) after its electrolytic hydrogenation and 500-h relaxation. It is shown that the structural variations in the foil during the β → α transformation are nonmonotonic.  相似文献   

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Two silicate glasses which have different acoustic properties and different thickness, were taken as the specimens, their frequency dependences of the longitudinal attenuation coefficients were measured in the frequency range of 50 to 300 MHz by the pulse reflection method, and the diffraction loss included in the measurement was corrected by theoretical calculation using A. O. Williams' expression. It has been shown that the measurement error of attenuation coefficient due to diffraction loss could be corrected very well by this method, regardless of the thickness of specimens.  相似文献   

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New data on variations in vertical distribution of stratospheric ozone overMoscow in the cold half-year of 2015–2016 are presented. This period differed significantly from previous winters in a number of stratospheric parameters. The features of these ozone variations are considered and their relation to the stratospheric dynamics is studied. The most significant decrease in the ozone concentration in comparison with average values was observed at the beginning of March, 2016. The development of further significant ozone layer depletion similar to that occurred in spring 2011 was prevented by major sudden stratospheric warming in March 2016.  相似文献   

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Physics of Atomic Nuclei - A review is given of measurements of the first five polarization coefficients $${{A}_{0}}$$ – $${{A}_{4}}$$ of angular distributions of muons resulting from the Z0...  相似文献   

9.
We make several observations concerning the low quark mass region with Wilson fermions and how this is connected with the ? regime in the continuum. A transition from tiny cutoff effects to rather large discretization errors would take place in general with Wilson fermions if we lower the quark mass at finite lattice spacing. We argue that these two regions exhibit rather different behaviours concerning the coupling between cutoff effects and zero-modes. We interpolate between these two regimes adding to the continuum ? regime formulae, in the spirit of the Symanzik expansion, the relevant operators parametrising the leading cutoff effects. We compute the partition function, the chiral condensate, scalar and pseudo-scalar correlation functions. The final formulae can be used to fit lattice data to extract physical low energy constants, and to estimate systematic uncertainties coming from discretization errors. Moreover they suggest ways on how to remove these cutoff effects, the core of which are captured by the continuum zero modes.  相似文献   

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We study the possibility of the small-polaron creation in α-helix proteins, accounting for the self-trapping of the intramolecular vibration energy quanta. The small-polaron concept of energy transfer in polypeptides has been revisited on the basis of these results. It was found that traditional small-polaron theories cannot be directly applied to the vibrational quanta transfer in these substances. In particular, true eigenstates of system should correspond to a partial dressed polarons rather than to the fully dressed small polaron states.  相似文献   

11.
A. W. Thomas 《中国物理 C》2010,34(9):1153-1156
One of the most fascinating challenges facing modern strong interaction physics is to understand the origin of the spin of the nucleon in terms of the spin and orbital angular momentum of the quarks and gluons.We review recent progress on this problem as well as some of the uncertainties associated with state of the art lattice QCD simulations.In particular,we explain the importance of the corrections associated with chiral extrapolation and finite volume corrections,especially for the term B(0) extracted from the appropriate low moment of the deeply virtual Compton scattering amplitude.  相似文献   

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In connection with my previous paper Locality, Reflection, and Wave-Particle Duality [Found. Phys. 17, 813 (1987)], in this paper I distinguish explicitly, in the locality problem, between assertions, deductively established results, interpretations, intuitions, and facts. This clarifies the structure of the problem.  相似文献   

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Possible types of time dependences p(t) describing the kinetics of the βα a transformation in the Pd-H system are presented based on the theory of hierarchical structures. It is shown that one factor influencing the change in the time dependence p(t) is the degree of regularity in the distribution of defects in the hierarchical complexes and the strength of the hierarchical coupling determining the number of hierarchically coupled levels. Analysis of the relations obtained and the experimental data made it possible to distinguish the most likely physical causes for the retardation of the βα a transformation. Fiz. Tverd. Tela (St. Petersburg) 49, 1621–1626 (September 1999)  相似文献   

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We study the finite size effects on Bose–Einstein condensation (BEC) of an ideal non-relativistic Bose gas in the three-sphere (spatial section of the Einstein universe) and in a partially finite box which is infinite in two of the spatial directions (infinite slab). Using the framework of grand-canonical statistics, we consider the number of particles, the condensate fraction and the specific heat. After obtaining asymptotic expansions for large system size, which are valid throughout the BEC regime, we describe analytically how the thermodynamic limit behaviour is approached. In particular, in the critical region of the BEC transition, we express the chemical potential and the specific heat as simple explicit functions of the temperature, highlighting the effects of finite size. These effects are seen to be different for the two different geometries. We also consider the Bose gas in a one-dimensional box, a system which does not possess BEC in the sense of a phase transition even in the infinite volume limit.  相似文献   

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正We have recently pointed out [1] that the string swampland conjectures [2], if true, provide important constraints on dark energy models. The constraints apply to the field range of a scalar field?described by an effective field theory, and to the slope of the potential Ⅴ of such fields. Specifically, we considered the consequence of the constraint  相似文献   

18.
Rebound Effect in the Kerr-Newman-Kasuya Field   总被引:1,自引:0,他引:1       下载免费PDF全文
It is shown that the repulsive gravitational action of electric charge and magnetic charge make it possible that the neutral particles moving in the Kerr-Newman-Kasuya field stop and rebound at the surface of r = ro =(e^2 q^2)/(2m). The phenomenon of dragging of inertial frames is analysed.  相似文献   

19.
This note is a part of my effort to rid quantum mechanics (QM) nonlocality. Quantum nonlocality is a two faced Janus: one face is a genuine quantum mechanical nonlocality (defined by the Lüders’ projection postulate). Another face is the nonlocality of the hidden variables model that was invented by Bell. This paper is devoted the deconstruction of the latter. The main casualty of Bell’s model is that it straightforwardly contradicts Heisenberg’s uncertainty and Bohr’s complementarity principles generally. Thus, we do not criticize the derivation or interpretation of the Bell inequality (as was done by numerous authors). Our critique is directed against the model as such. The original Einstein-Podolsky-Rosen (EPR) argument assumed the Heisenberg’s principle without questioning its validity. Hence, the arguments of EPR and Bell differ crucially, and it is necessary to establish the physical ground of the aforementioned principles. This is the quantum postulate: the existence of an indivisible quantum of action given by the Planck constant. Bell’s approach with hidden variables implicitly implies rejection of the quantum postulate, since the latter is the basis of the reference principles.  相似文献   

20.
Optical absorption measurements ofZ 2 andZ 2 + centers in KCl:Ca are combined with electron spin resonance experiments in order to reveal the electronic and atomistic structure of these centers.Z 2 + centers are alignable in the crystal by polarized optical irradiation at suitable temperatures. From orientedZ 2 + centers equally orientedZ 2 centers can be produced, both types of centers showing a (100) axial symmetry. ConcerningZ 2 this is also confirmed by ESR measurements on their triplet state produced by optical excitation. Polarized excitations allow a determination of the ratio of oscillator strengths for transitions parallel and perpendicular to the center axis using the variations in ESR line intensities. ForZ 2 f /f =1.6 is found in this way; decomposition of the dichroism ofZ 2 + centers gives for this speciesf /f =1.8. It is shown that theZ 2(Ca) center is a molecule made up of a Ca++ ion and an anion vacancy in (100) nearest neighborhood, sharing two electrons with antiparallel spins in the ground state. Both, withZ 2 andZ 2 + , the absorption bands at lowest energies are best explained bys—d charge transfer transitions.  相似文献   

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