首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
Slow production via dd-CF using a two-layer arrangement is investigated. To determine its feasibility, experimental measurements are now in progress using the muonic X-ray detection method. The following experimental steps are being considered: (1) measurement of the number of stopped inside a solid H2/D2 layer by detecting p K X-rays, (2) hot d emission detection by placing a secondary target at a distance of 10–30 mm from the layer and by detecting specific delayed X-rays, (3) measurement of the disappearance of d emission as the added D2 layer is increased, (4) dd-CF measurement by detecting fusion protons, and (5) slow emission detection. Results of the initial test experiment are presented.  相似文献   

2.
The method of complex angular moments is used to analyze the experimental data on the inelastic reactions p ()K, taking into account branch cuts in the j-plane in the eikonal approximation. An optical model for the backward scattering is considered. Agreement with experiment is obtained in the region of small angles for the reactions (0)K0. In the case of P K0(K+) processes, agreement is obtained with the experimental results for large (180) scattering angles.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 26–30, August, 1972.  相似文献   

3.
LetH l be the Hamiltonian in aP()2 theory with sharp space cutoff in the interval (–l/2,l/2). LetE l =inf(H l ), (l)=–E l /l, and let l be the vacuum forH l . discuss properties of (l) and l . In particular, asl, there are finite constants <0 and such that (l), ((l)–)l, and hence (l)=+/l+o(l –1). Moreover exp(–c 1 l) l 1exp(–c 2 l) forc 1,c 2 positive constants, where l 1 is theL 1(Q, d0) norm of 1 with respect to the Fock vacuum measure. We also present a new proof of recent estimates of Glimm and Jaffe on local perturbations ofH l in the infinite volume limit.Research sponsored by AFOSR under Contract No. F44620-71-C-0108.On leave from Istituto di Fisica Teorica, Universitá di Napoli and Istituto Nazionale di Fisica Nucleare, Sezione di Napoli.A. Sloan Foundation Fellow.  相似文献   

4.
It is shown for a one-dimensional approximation that, around a disturbance in the ion concentrationn +(x, t) in the axial direction of a cylindrical plasma, a corresponding electron distributionn (x, t) is established with such a large velocity that under the usual conditions of a discharge plasma this electron distribution follows the relatively slow changes in ion concentration practically without delay. Relation (24) then holds for the electron concentration, the parametersl 1,l D being given by Eqs. (15) and (16). As long as the disturbance of the ions isn +(x) 0, a space chargeq 0(n +-n) is produced and maintained in the plasma even if the disturbance of the equilibrium state of the plasma in the initial stage was electrically neutral (i.e.n +(x, t=0)==n (x,t=0)). The dimensions of these space charges can be many orders larger than the Debye characteristic lengthl D ; this is shown on an example of a spatially periodic curven +(x). The unique (quasi-stationary) expression of the electron concentrationn by means of the deflection of the ion concentrationn +(x, t) permits a considerable simplification of the solution of the problems connected with axially disturbing the homogeneous state of a plasma, sincen (x, t) can be eliminated from the equations of continuity of the plasma by substituting from (24), and the problem becomes that of determining the curve of the ion concentrationn + from the equations modified in this way.
, +(, t) - (, t) , . (24), l 1 l D (15) (16). +() 0, q 0(n+ — n), , (..n +(x,0)=(, 0)). () +(, t) , , . . (, t) n + .
  相似文献   

5.
The contributed papers submitted to the session C Hypernuclear and kaon physics and not presented orally at the Conference are briefly reviewed here.Rapporteur talk at the symposium Mesons and Light Nuclei IV, Bechyn, Czechoslovakia September 5–10, 1988.  相似文献   

6.
A study has been made of the effects of radiation corrections of order as regards the probability of lepton decay of a moving neutral vector meson V e+e and V + (V = 0, , ); -e universality has been checked by examining the effects of radiation corrections due to exchange of virtual photons between lepton and antilepton, and also to vacuum polarization by e+e electron and +muon closed loops; in addition, a study has been made of the emission of soft photons as regards the partial width for the electron and muon modes of V-meson decay. Closed expressions (1), (4), and (5) for the corrections imply that the ratio ¦Rv¦ for the probabilities of decay of a V meson to e+e and +, which are given by (11), agree well with the available evidence on 0 e+e + decays and indicates a possible deviation from -e universality in e+e+ decays.Read at the meeting on high-energy physics, Nuclear Physics Section Academy of Sciences of the USSR (Moscow, February 11–15, 1974).Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 84–89, July 1975.We are indebted to Professor A. A. Sokolov for a discussion.  相似文献   

7.
An expression for the decay rate (0 ) has been derived in the frameworkof the spinor strong interaction theory, a first-principles strong interaction theoryproposed some years ago as an alternative to low-energy QCD. The startingpoint is the SO(3) gauge-invariant action for two quark mesons which has beensuccessful in accounting for confinement, + + , e+, and 0 e+, nonexistenceof the Higgs boson, and other low-energy mesonic phenomena. The quasi-four-quarkmeson equations developed for the decay of a vector meson into twopseudoscalar mesons V PP has been taken over here to apply to P(0) VV(+ ) (plus + and which annihilate each other). This mechanismin principle agrees with that of the assumption of vector meson dominance inthe literature. It, together with the effect of form factors, arises naturally in theformalism and need not be assumed. Equations for the perturbed vector mesonwave functions cannot be simply solved and an assumption has been made toobtain an estimate of their magnitude. Together with a constant associated withthe strong coupling obtained earlier from V() PP(K+K), the estimated decayrate is 19.2 eV, in order-of-magnitude agreement with data (7.74 eV).  相似文献   

8.
Scalar scattering of light on the 3p and 3s subshells of the argon atom (Stokes scattering) and anti-Stokes scattering on the excited 4p and 4s states of argon are examined in the Hartree-Fock approximation. The calculation is made in a velocity form and in a length form. It is shown that the value in the r form is 1.5–2 times greater than in the form.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 36–42, January, 1977.  相似文献   

9.
The contact angle at the intersection of a grain boundary in Al bicrystals with the solid Al/liquid Al–Sn interphase boundary has been measured for two symmetric tilt <011> {001} grain boundaries with tilt angles of 32° and 38.5°. The temperature dependencies (T) present the evidence of the grain boundary wetting phase transition at Tw. The observed hysteresis is consistent with the assumption that the wetting transition is of first order. The determined discontinuity in the temperature derivative of the grain boundary energy is–5.6 J/m2K (T w1=617°C) for the boundary with a low energy (=38.5°) and –17 J/m2K (T w2=604°C) for the grain boundary with a high energy (=32°).  相似文献   

10.
Numerical simulations are done of Langevin dynamics for a uniform-orderparameter, field-swept Landau model,= –|a/2|m 2+|b/4|m 4mh(t) , to study hysteresis effects. The field is swept at a constant rateh(t)=h(0)+ht. The stochastic jump values of the field {hJ from an initially prepared metastable minimumm(0) are recorded, on passage to a global minimum m(). The results are: (a) The mean jump¯h J(h) increases (hysteresis loop widens) with h, confirming a previous theoretical criterion based on rate competition between field-sweep and inverse mean first-passage time (FPT); (b) The broad jump distribution(h J,h) is related to intrinsically large FPT fluctuations ( 22)/ 2 O(1), and can be quantitatively understood. Possible experimental tests of the ideas are indicated.  相似文献   

11.
The emissivity in the 2.7 m range is examined with a spectrometer having 25 cm–1 for 2.5, ,7.5 cm·atm,4 8cm·atm, 400T1000° K; 150P730 mm Hg. It is found that relation (1) is obeyed to within /0.1, though the calculated transmission is usually less than the measured value. It is shown that the relation is obeyed on account of the mutual position of the CO2 and H2O lines in the band, i.e., one gas may be considered as unselective relative to the other.  相似文献   

12.
The paper deals with the problem of the anomalous divergence of an infinite geometric series of complex amplitudes, pointed out by Berning. It is shown that the paradox is of a formal mathematical nature and has no consequences for multiple beam interference as a method of derivation.
, . , - .
  相似文献   

13.
The half-life of64Cu in Cu–Au solid solutions has been measured as a function of the Cu concentration. Relative changes of electron densities (0)/(0) at the Cu nucleus are deduced. The observed nonlinear concentration dependence of (0)/(0) is discussed in terms of volume and charge transfer effects.  相似文献   

14.
The basic equations of the dynamics of the continuous distribution of dislocations analogical to Maxwell equations are derived in a series of papers [I, II, III]. The analogy of the elastic and electromagnetic fields is analyzed. In part [III] some special problems are discussed, such as the density of the forces acting on the dislocations, the energy dissipation during the movement of dislocations, which is expressed by an equation analogical to Ohm's law. The equations derived in the previous parts in four-dimensional symbolics are considered in the three-dimensional differential and integral form. It is found that in special cases the relations become the known ones of elastodynamics, hydrodynamics and the static theory of the continuous distribution of dislocations. It is found that Kröner's method of integrating the equations of the dislocation field by means of so-called incompatibility tensors is analogical to the integration of the Maxwell equations by means of Hertz vectors. The analogy between the elastic dislocation field and the electromagnetic field is discussed in detail.
III.
, . . : , , , , . , , . , , . , . .
  相似文献   

15.
16.
17.
The review of new theoretical and experimental results in the field of the pion-nucleus interaction which are presented in the contributed papers at the IV International symposium Mesons and Light Nuclei (Bechyn, 1988) is given. The discussion covers a wide area of problems from the -nucleon interaction to the pion interaction with light nuclei at low and intermediate energies.Rapporteur talk at the symposium Mesons and Light Nuclei, IV, Bechyn, Czechoslovakia, September 5–10, 1988.  相似文献   

18.
The nonlinear wave equation, tt –+3=0, has many solutions that are periodic in time and localized in space, all with infinte energies. The search for spherically symmetric solutions that are well represented by the simple approximation, (r, t)A(r) sin t, leads to a discrete spectrum of solutions{ N (r, t; )}. The solutions are nonlinear wavepackets, and they can be regarded as particles. The asymptotic theory () of the motion of the guiding center of theNth wavepacket, in the presence of a specified potential, is characterized by an infinite mechanical mass and an infinte interaction mass, and they are compatible. The rest mass in the classical relativistic mechanics of guiding centers ism 0 c 2= N ; i.e. the spectrum { N } determines a spectrum of Planck's constants.On leave (1972–73) Université de Paris VI, Département de Mécanique, 75 Paris 5e, France.  相似文献   

19.
The magnetic after-effect caused by the diffusion of electrons was studied in detail in MnMg ferrites of the series Mg x Mn1.15–x Fe1.85O4+ ; the comparative measurements were also carried out on a sample of MgFe2O4+(<0). By combining the two methods, (a) investigation of the disaccommodation of initial permeability at different temperatures and (b) measurement of the displacement of the maximum of the temperature dependence tan with the frequency, it was possible to study the relaxation processes whose time constants lay between 0.5 sec and several hours, or between 10–4 to 10–7 sec. It was found that the processes taking place at low temperatures and studied by method (a) differ from those observed at high temperatures by method (b), particularly in the lower activation energies and greater dispersion of the time constants. In addition to these two main relaxation processes a weak relaxation superposed over the main disaccommodation was found in ferrites with non-zero content of manganese. An analysis of the intensity of different relaxation effects showed the participation of Mn ions in these relaxation effects and it was found that both main relaxations are probably equivalent as regards the final steady state, to the creation of which they lead; they differ however in the mechanism of electron diffusion by which this state is realized. The main features of the different diffusion mechanisms are discussed.
-
, , MnMg Mg x Mn1.15–x Fe1.85O4+ . MgFe2O4+ (<0). ()- , () tg , , 0,5 sec , 10–4–10–7 sec. , , () , , (), , , . , . Mn , , , , , ; , , , . .


In conclusion the author thanks Dr. J. Bro and K. Závta for valuable discussion and F. Vilím for carefully carrying out the measurements.  相似文献   

20.
We derive the exact matrix field theory for a replicated grassmannian representation of a local pairing superconducting disorder ensemble including three superconducting order parameters and the spin-flip pairbreaking mechanism. Disorder is assumed to be gaussian distributed. We find by exactly solving the saddle-point equation the criterion for a vanishing gap –1 + –1 , where denotes the averaged superconducting order parameter, –1 the spin-flip scattering rate, and –1 the scattering rate corresponding to correlations of Re(–). Taken at =0, our field theory, which is exact in all orders of –1 , contains new terms in addition to those of theO( –1 ) model derived by Efetov et al. Our formulation transfers correctly to all orders the invariances of the action into symmetries of the matrix field theory. The saddle point approximation is outlined and it is shown how singular corrections to the saddle point density of states arise atE F in a gapless superconductor. Finally singular corrections in the two particle propagator, the density correlation function and the conductivity are calculated for =0 in one loop order. It turns out that these corrections can be entirely expressed by those of the single particle density of states.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号