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1.
ForA any subset of () (the bounded operators on a Hilbert space) containing the unit, and and restrictions of states on () toA, ent A (|)—the entropy of relative to given the information inA—is defined and given an axiomatic characterisation. It is compared with ent A A (|)—the relative entropy introduced by Umegaki and generalised by various authors—which is defined only forA an algebra. It is proved that ent and ent S agree on pairs of normal states on an injective von Neumann algebra. It is also proved that ent always has all the most important properties known for ent S : monotonicity, concavity,w* upper semicontinuity, etc.  相似文献   

2.
Let be an infinite dimensional Hilbert space and () the set of all (orthogonal) projections on . A comparative probability on () is a linear preorder on () such thatOP1,1O and such that ifPR,QR, thenPQP+RQ+R for allP, Q, R in (). We give a sufficient and necessary condition for to be implemented in a canonical way by a normal state onB(), the bounded linear operators on .  相似文献   

3.
A rigorous construction of new super-selection selectors — so-called soliton-sectors — for the quantum sine-Gordon equation and the (·)2-quantum field models with explicitly broken isospin symmetry in two space-time dimensions is presented. These sectors are eigenspaces of the chargeQdx(grad )(x) with non-zero eigenvalue. The scattering theory for quantum solitons is briefly discussed and shown to have consequences for the physics in the vacuum sector. A general theory is developed which explains why soliton-sectors may exist for theories in two but not in four space-time dimensions except possibly for non-abelian Yang-Mills theories.Supported in part by the National Science Foundation under Grant NSF-GP-39048 and by the ETH, Zürich.  相似文献   

4.
Inflationary cosmology makes the universe eternal and provides for recurrent universe creation, ad infinitum — making it also plausible to assume that our Big Bang was also preceeded by others, etc.. However, GR tells us that in the parent universe's reference frame, the newborn universe's expansion will never start. Our picture of reality in spacetime has to be enlarged.Wolfson Distinguished Chair in Theoretical Physics.Also on leave from the University of Texas, Center for Particle Physics, Austin, Texas.  相似文献   

5.
We continue the analysis of the conjugate equation for the generating function of a Gibbs random point field corresponding to a stationary solution of the classical BBGKY hierarchy. This equation was established and partially investigated in the preceding papers under the same title. In the present paper we reduce a general theorem about the form of solutions of the conjugate equation to a statement which relates to a special case where the interacting particles constitute a quasi—one dimensional configuration.  相似文献   

6.
From analysis of anisotropical lattice bands properties of 50 reflection spectra both of the CO stretching and bending bands measured from some pearl (Ca++CO 3 –– or Ca++HCO 3 –– layer) we discussed following subjects.i) Quantized properties present both in reflectivity and in energy. ii) classifications of the Optical Activity. iii) Polar distributions of the CO3 oscillators in Ca++CO 3 –– surface mono-layer. iv) Force constants of these oscillators. v) Step variation of the dipolemoment and their influences to the degree of Optical Activity. vi) Two types of hysteresis loops of the values of YN (M2Jbend ()/M1Jstret. ()) derived from the oscillators which are at innert-state, at weak active-state and at active-state.  相似文献   

7.
We analyze the low-temperature phase of ferromagnetic Kax-Ising models in dimensionsd2. We show that if the range of interactions is –1, then two disjoint translation-invariant Gibbs states exist if the inverse temperature satisfies –1N, where =d(1–)/(2d+2)(d+1), for any >0. The proof involves the blocking procedure usual for Kac models and also a contour representation for the resulting long-range (almost) continuous-spin system which is suitable for the use of a variant of the Peierls argument.  相似文献   

8.
In the special type of the quark model we obtain the ratio=h A/hV of the axial (hA) and vector (hV) form factors for the decays e ¯ve and K e¯ve different from unity. The low-energy theorem, relating the electric polarizability of the charged pion with the ratio, is analyzed. It is shown that < 1 corresponds to , calculated by accounting the contribution of the scalar meson(700) into the amplitude of the Compton effect on the pion. In the absence of the(700) contribution we have=1.Dedicated to Academician Václav Votruba on the occasion of his eightieth birthday.  相似文献   

9.
10.
The magnetic properties of thin ferromagnetic films are studied taking into account the magnetic anisotropy term in the Hamiltonian. In the second approximation equations are obtained for the magnetization of the monatomic layers parallel to the surface of the thin film. From these equations one obtains the Curie temperature, which depends on the thickness of the thin film and the ratio a between the anisotropy constant and the exchange energy between two neighbours. A value can be chosen for such that the thin film becomes ferromagnetic only for a thickness greater than a definite value and in this manner the theoretical results can be fitted to the experimental data. The situation in cobalt thin films is dealt with in particular.
. , . , . , , - , . , , .


The author extends his thanks to the research workers of CIFA 1 as well as to Dr. L. Valenta for information on the same subject.  相似文献   

11.
The potentials of an electromagnetic field of multipoles in a dielectric, which is realized by a dielectric sphere having a perfectly conducting surface, are derived. The diagonal values of the energy for thez component of the angular momentum and the square of the angular momentum of the field are determined and also the ratio between thez component of the angular momentum and the energy and the ratio between the square of the angular momentum and the square of the energy. It is shown that the total angular momentum can be divided in the usual way into orbital and spin parts but that these parts cannot be interpreted as the orbital and spin angular momentum because their eigenvalues cannot be the eigenvalues of any operator of infinitesimal rotation. In the commutation rules of a multipole field the vector character of the field is to a certain extent suppressed and the spin of the photon in a state with a certain value of the energy, parityz component of the angular momentum and the square of the angular momentum is not defined.
, . ,z— , , z— . , , , , , - . , ,z— .


In conclusion the author thanks Dr. . Muziká for directing the work, F. Samek for valuable remarks and discussion and J. Kvasnica for help in preparing the paper for publication and for adding a number of remarks.  相似文献   

12.
PLD and CVD methods, plasma or bias assisted, have been used to prepare thin films of nano-clustered graphite. The experimental conditions (vz. deposition apparatus, substrate temperature, working pressure, inert sustaining gases, parent species, and applied voltage) have been changed with the final aim of obtaining small graphene particles with the basal planes oriented along the growth vector and perpendicular to the n-Si100 substrate. Pulsed laser ablation (Nd:YAG, 2nd harmonic: =532 nm, h=2.33 eV, =7 ns, =10 Hz, 7 J/cm2), assisted by an RF-plasma, of a pyrolytic graphite target gave good results for nano-structure formation, provided high substrate temperature and high inert gas pressure are maintained. CVD methods, in the presence of high substrate temperature and a DC bias, showed a good attitude to drive a longitudinal growth of graphene layers and nano-wires from a reactive gas flow of Argon/Hydrogen and Methane. The morphology of the films grown at different conditions have been characterised by scanning electron microscopy (SEM). Film quality and nano-particle dimensions have been estimated by Raman spectroscopy. PACS 81.07.-b; 81.15.-z; 78.30.-j; 68.37.-d  相似文献   

13.
A fully micro realistic, propensity version of quantum theory is proposed, according to which fundamental physical entities—neither particles nor fields—have physical characteristics which determine probabilistically how they interact with one another (rather than with measuring instruments). The version of quantum smearon theory proposed here does not modify the equations of orthodox quantum theory: rather it gives a radically new interpretation to these equations. It is argued that (i) there are strong general reasons for preferrring quantum smearon theory to orthodox quantum theory; (ii) the proposed change in physical interpretation leads quantum smearon theory to make experimental predictions subtly different from those of orthodox quantum theory. Some possible crucial experiments are considered.  相似文献   

14.
The structure function S(k; ) for the one-dimensional one-component log–gas is the Fourier transform of the charge–charge, or equivalently the density–density, correlation function. We show that for |k|j in the power series expansion of f(k; ) about k=0 is of the form of a polynomial in /2 of degree j divided by (/2)j. The bulk of the paper is concerned with calculating these polynomials explicitly up to and including those of degree 9. It is remarked that the small k expansion of S(k; ) for the two-dimensional one-component plasma shares some properties in common with those of the one-dimensional one-component log–gas, but these break down at order k8.  相似文献   

15.
A study is made of the non-radiative transfer and diffusion of excitation energy in molecular crystals containing foreign molecules and its influence on the luminescent properties of these crystals.
,
, .
  相似文献   

16.
17.
/M1 ( — ,M — ) (= 1/137) - . 0,2% –v/c, , .
Radiative corrections to the electron polarization in the beta decay of a free neutron
An expression for the electromagnetic radiative corrections of the order (=1/137) to the longitudinal polarization degree of the electron in the beta decay of a free neutron is derived in the approximation /M1 ( is the neutron-proton mass difference,M — mass of the neutron). The corrections are not larger than 0·2% and it seems that they cannot explain the deviation of the experimental value for the electron polarization from the value –v/c (measured in the beta decay of nuclei).


. . . . . .  相似文献   

18.
The brightness waves of electroluminescence of ZnS—Cu were measured for the case of excitation with rectangular pulses as a function of the amplitude of the pulses and the temperature. A concrete model is proposed for electronic processes in barriers in ZnS crystals, the consequences of which for the decay of electroluminescence are in agreement with measurements.
ZnS-Cu,
e ZnS-Cu . ZnS-Cu, .


In conclusion the author thanks M. Trlifaj for valuable remarks and discussions, Z. Vojta and E. Rechziegel for constructing an important part of the apparatus and F. Karel for the electroluminescent crystals.  相似文献   

19.
20.
In this paper the magnetic properties of ferromagnetic thin layers are studied by calculating the partition function for the magnetic system inKirkwood's approximation of the second order. The results obtained for the Curie temperature and the magnetization are in somewhat better agreement with the experiment than those obtained by Valenta.
. , , .


The author extends his thanks to the group of research workers who performed the numerical calculation of the Curie temperatures on the computer CIFA 1, as well as gratitude to Dr. l. Valenta for so kindly supplying information on the results of his investigations on the same subject.  相似文献   

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