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1.
The decay of Re 186 was investigated with a double focusing spectrometer and scintillation spectrometer. Four transitions were observed with energies of 122·7±0·1 keV, 137·2 keV, 632·2±1·5 keV and 768·2±1·5 keV and the relative-ray intensities 18, 246, 0·9 and 1 respectively. TheK-conversion coefficients determined for low-energy transitions are in good agreement with the theoretical values (
K
122·7
=0·53±0·05,
K
137·2
=0·44±0·02). The relative intensities of theK, L, M andN conversion lines were also determined for these transitions:KL
I
+IIL
III
M=1·20±0·201·32±0·20 1±0·150·57±0·08 for 122·7 keV transition,KL
I
+IIL
III
MN=1·57±0·081· 72±0080·70±0·030·20±0·01 for 137·2 keV transition. In the beta spectrum two groups were observed with the end points of 1076±3 keV and 939±3 keV and relative intensities 74±4% and 21±4% respectively. For the branching ofK-capture it was found that 1·5% populates the 122·7 keV level and 3·5% the ground state. The decay scheme from the present results is proposed.The authors would like to thank M. Buriánek and V. Kopiva for help in the measurements. 相似文献
2.
The initial permeability disaccommodation in ferritesMn
x
Fe3–xO4+
, 0·5x1, was studied in a temperature range around –200°C to +180°C. Four separate bands were found in the relaxation spectrum of these ferrites.
Mn x Fe3–x O4+
Mn x Fe3–x O4+ , 0,5x1, –200°C +180°C. .相似文献
3.
G. A. Mezincescu 《Communications in Mathematical Physics》1986,103(1):167-176
The integrated density of states has C-like singularities, ln|k(E)–k(E
c
)|=–|E–E
c
|–v/2
c
(E), with
c
>0, a milder function at the edges of the spectral gaps which appear when the distribution function of the potentiald has a sufficiently large gap. The behaviour of
c
nearE
c
is determined by the local continuity properties ofd near the relevant edge:
c
(E)=O(1) ifd has an atom and =O(ln|E–E
c
|) if is (absolutely) continuous and power bounded. 相似文献
4.
H. W. Gronert D. M. Herlach A. Schröder R. van den Berg H. von Löhneysen 《Zeitschrift für Physik B Condensed Matter》1986,63(2):173-178
Low-temperature measurements of the thermal conductivity (0.3KT5K) and of the specific heatC (0.07KT3.5K) of splat-cooled amorphous superconducting Zr0.67Ni0.33(T
c
2.7K) after different annealing stages are reported. increases progressively (up to 55%) after annealing. An analysis of with the help of normal-state measurements belowT
c
in an overcritical field shows that the phonon-electron scattering remains unaltered after annealing. Hence the increase in must be entirely attributed to structure-induced (intrinsic) scattering, i.e. by two-level tunneling states (TLS) at low temperatures (T1K). The specific heat shows a small decrease aboveT
c
(by 8%) which is attributed to a small diminution of the electronic density of states at the Fermi level and to a small increase in the Debye temperature. ForTT
c
where TLS dominate, the specific heatC decreases less upon annealing than expected from the increase of in the standard tunneling model. This points to a change in the TLS relaxation time spectrum upon annealing, as observed previously for Zr
x
Cu1–x
glasses. 相似文献
5.
Rinaldo Schinazi 《Journal of statistical physics》1994,74(5-6):1005-1016
The contact process onZ has one phase transition; let
c
be the critical value at which the transition occurs. Let
N
be the extinction time of the contact process on {0,...,N}. Durrett and Liu (1988), Durrett and Schonmann (1988), and Durrett, Schonmann, and Tanaka (1989) have respectively proved that the subcritical, supercritical, and critical phases can be characterized using a large finite system (instead ofZ) in the following way. There are constants 1() and 2() such that if <
c
, lim
N
N
/logN = 1/1(); if >
c
, lim
N
log
N
/N = 2(); if =
c
, lim
N
N
/N= and lim
N
N
/N
4=0 in probability. In this paper we consider the asymmetric contact process onZ when it has two distinct critical values
c1<
c2. The arguments of Durrett and Liu and of Durrett and Schonmann hold for <
c1 and >
c2. We show that for [
c1<
c2), lim
N
N
/N=-1/, (where
i
is an edge speed) and for =
c2, lim
N
log
N
/logN=2 in probability. 相似文献
6.
Quantum shot noise consists of individual pulses which contribute time-dependent (operator) potentials toward a total potentialV(t). The averaged quantity T exp
t0
t
dtV(t) in general can no longer be calculated explicitly, in contrast to the classical case, and expansions are of interest. Noncommutative cumulant expansions are not directly applicable if the correlation functions ofV(t) have singularities, as happens in applications. It is shown here that these expansions, when applied to quantum shot noise, can be partially summed to give expansions in powers of the pulse density. Three types of such expansions are established explicitly, and for two of them the derivation is direct. For one of them the first-order approximation is closely connected to the so-called unified theory of spectral-line broadening. 相似文献
7.
E. Boschitz 《Czechoslovak Journal of Physics》1986,36(2):215-224
Summary There has been remarkable experimental and theoretical progress in the field ofd interactions in the last few years. Within the uncertainties of the theory the experimental data in thed breakup and thed elastic scattering reaction can be fairly well reproduced. Theoretical problems remain in the absorption channel, but there is a hope that with a few additional measurements of tensor polarization and spin transfer observables in this reaction a partial wave amplitude analysis may localize the theoretical difficulties. In addition it is very important to provide data on the deuteron tensor polarizations and the spin transfer parameters for thed elastic scattering reaction in order to obtain a reliable set of phase shifts, which may reveal resonance structures in this reaction channel.Invited talk to the symposium Mesons and Light Nuclei, Bechyn, Czechoslovakia, May 27–June 1, 1985. 相似文献
8.
We establish a new three-mode entangled state representation , of continuum variables, which make up a complete set. Using optical four-wave mixing and a beam splitter transform we can prepare , . Based on , a new number-difference--operational-phase uncertainty relation is established and the corresponding squeezing dynamics is discussed. 相似文献
9.
A. Ja. Režnikova 《Journal of statistical physics》1981,25(2):291-308
Let HL = –d2/dt2+q(t,) be an one-dimensional random Schrödinger operator in 2(–L, L) with the classical boundary conditions. The random potential q(t,) has a form q(t, )=F(xt), where xt is a Brownian motion on the Euclidean v-dimensional torus, FSv R1 is a smooth function with the nondegenerated critical points, mins
v F = 0. Let
are the eigenvalues of HL) be a spectral distribution function in the volume [– L,L] and N() = limL(1/2L)NL() be a corresponding limit distribution function.Theorem 1. If L then the normalized difference N
L
*
()=[NL() -2L·N()]2L tends (in the sense of Levi-Prokhorov) to the limit Gaussian process N*(); N*()0, 0, and N*() has nondegenerated finitedimensional distributions on the spectrum (i.e., > 0). Theorem 2. The limit process N*() is a continuous process with the locally independent increments. 相似文献
10.
M. Ghosh A. K. Sen B. K. Chakrabarti G. A. Kohring 《Journal of statistical physics》1990,61(1-2):501-504
The variation of the convergence time, as a function of the storage capacity is studied numerically for systems ranging in size fromN=1000 toN=16,000 neurons. is found to increase likeexp[–A(c–)] as one nears the critical storage capacity
c
=0.142=0.002. 相似文献
11.
We review some exact results for the motion of a tagged particle in simple models. Then, we study the density dependence of the self-diffusion coefficientD
N() in lattice systems with simple symmetric exclusion in which the particles can jump, with equal rates, to a set ofN neighboring sites. We obtain positive upper and lower bounds onF
N()=N{(1–)–[DN()/DN(0)]}/[(1–)]x for [0, 1]. Computer simulations for the square, triangular, and one-dimensional lattices suggest thatF
N becomes effectively independent ofN forN20. 相似文献
12.
Abraham Boyarsky 《Journal of statistical physics》1988,50(1-2):213-229
Let : [0, 1][0, 1] be a piecewise monotonie expanding map. Then admits an absolutely continuous invariant measure. A result of Kosyakin and Sandler shows that can be approximated by a sequence of absolutely continuous measures
n
invariant under piecewise linear Markov maps itn. Each itn is constructed on the inverse images of the turning points of . The easily computable measures
n
are used to estimate the Liapunov exponent of . The idea of using Markov maps for estimating the Liapunov exponent is applied to both expanding and nonexpanding maps. 相似文献
13.
Matsuta K. Minamisono T. Tanigaki M. Fukuda M. Nojiri Y. Mihara M. Onishi T. Yamaguchi T. Harada A. Sasaki M. Miyake T. Minamisono K. Fukao T. Sato K. Matsumoto Y. Ohtsubo T. Fukuda S. Momota S. Yoshida K. Ozawa A. Kobayashi T. Tanihata I. Alonso J. R. Krebs G. F. Symons T. J. M. 《Hyperfine Interactions》1996,97(1):519-526
The magnetic moments of the proton drip-line nuclei13O(I
= 3/2–,T
1/2 = 8.6 ms) and 9C(I
= 3/2–,T
1/2 = 126 ms) have been determined for the first time through the combined techniques of polarized radioactive nuclear beams and-NMR detection. The observed magnetic moments are ¦(13O)¦ = 1.3891 ±0.0003
N and ¦(9C)¦ = 1.3914 ±0.0005
N. Spin expectation values are deduced to be 0.76 and 1.44 for13O and9C, respectively. While the of13O is consistent with the systematics from isospinT= 1/2 mirror pairs, the of9C is unusually large, even far larger than the single particle value, = 1. 相似文献
14.
Eduard Herlt 《General Relativity and Gravitation》1979,11(5):337-342
This paper shows that a new class of axially symmetric static electrovacuum/magnetovacuum solutions is obtainable from Weyl's class of static vacuum solutions. The new class contains an infinite set of asymptotically flat solutions (in closed form) each of which involves an arbitrary set (d, i) of parameters. These parameters have to be interpreted as functions of massm, chargee, and higher electric/magnetic multipole moments
i
of the particle. The cased = 0,
i
=0 leads to the Darmois solution and the cased = 0,
i
0 leads to the results of [1]. The case d=0, e=i=0 leads to the Schwarzschild solution, the cased 0,
i
=0,e 0 leads to the Reissner-Nordström solution. To get more general examples is a lengthy but straightforward exercise. 相似文献
15.
LetI be a set of invariants and be a set of angle variables for a system of differential equations with anO() vector field. When time dependent stochastic perturbations, also ofO(), are added to the system, we have shown that under suitable conditionsI becomes a stochastic adiabatic invariant satisfying a diffusion equation on time scales of order 1/2, in the limit as »0. Here we show that the angle variables converge weakly to a Gaussian Markov process on an O(-4/3) time scale, and thus the phase becomes randomized at these times. Application to nearly integrable Hamiltonian systems is considered.Supported by NSF grant DMR-8704348 相似文献
16.
Successive band-splitting transitions occur in the one-dimensional map xi+1=g(xi),i=0, 1, 2,... withg(x)=x, (0 x 1/2) –x +, (1/2 <x 1) as the parameter is changed from 2 to 1. The transition point fromN (=2n) bands to 2Nbands is given by=(2)1/N (n=0, 1,2,...). The time-correlation function
i=xix0/(x0)2,xi xi–xi is studied in terms of the eigenvalues and eigenfunctions of the Frobenius-Perron operator of the map. It is shown that, near the transition point=2,
i–[(10–42)/17] i,0-[(102-8)/51]i,1 + [(7 + 42)/17](–1)ie–yi, where2(–2) is the damping constant and vanishes at=2, representing the critical slowing-down. This critical phenomenon is in strong contrast to the topologically invariant quantities, such as the Lyapunov exponent, which do not exhibit any anomaly at=2. The asymptotic expression for
i has been obtained by deriving an analytic form of
i for a sequence of which accumulates to 2 from the above. Near the transition point=(2)1/N, the damping constant of
i fori N is given by
N=2(N-2)/N. Numerical calculation is also carried out for arbitrary a and is shown to be consistent with the analytic results. 相似文献
17.
Y. Zhou J. Zhou X. Chang F. Xia C. H. Shih 《Applied Physics A: Materials Science & Processing》1996,62(3):213-216
The microstructure of fiber-like SiC/Si3N4 composite particulate was investigated using high-resolution transmission electron microscopy techniques. The SiC/Si3N4 composite particulate consisted of a-SiC core and a -Si3N4 outer shell. Two kinds of composite particulate were distinguished when the observed orientation of the SiC core was <110>. In one type of the SiC/Si3N4 composite particulate, a crystal relationship of (111)-SiC | (102) -Si3N4 and (111)-SiC (114) -Si3N4 was identified; in the other type of the SiC/Si3N4 composite particulate, a crystal relationship of (111)-SiC (001) -Si3N4, and (111)-SiC (101) -Si3N4 was observed. 相似文献
18.
Interphase boundaries between 3C SiC grains and two different -Si3N4 morphologies in Si3N4–SiC composites have been studied by transmission electron microscopy. In general, boundaries between small -Si3N4 intragranular precipitates and surrounding SiC grains were relatively free of intergranular films, whereas boundaries between large -Si3N4 grains and adjacent SiC grains were invariably covered with thin intergranular films. Orientation relationships approximating to [110] 3C SiC [0001] -Si3N4 and (001) 3C SiC (10
0) -Si3N4 were found to dominate between 3C SiC grains and the intragranular -Si3N4 precipitates, but there was no evidence of any favoured orientation relationship between the large -Si3N4 grains and adjacent SiC grains. The rationale for special orientation relationships arising when there is no intergranular film present at 3C SiC–-Si3N4 interfaces is explored geometrically using the near-coincidence site lattice model, with the significant result that the dominant orientation relationships between 3C SiC grains and the intragranular -Si3N4 precipitates have low misfits relative to all other possible orientation relationships between 3C SiC and -Si3N4. 相似文献
19.
For classical point particles in a box with potential energy H(N)=N
–1(1/2)
ij=1
N
V(x
i,x
j) we investigate the canonical ensemble for largeN. We prove that asN the correlation functions are determined by the global minima of a certain free energy functional. Locally the distribution of particles is given by a superposition of Poisson fields. We study the particular case =[–L, L] andV(x, y)=}- cos(x–y),L}>0, }>0.References 相似文献
20.
The non-linear distribution of lattice strain
310vs sin2
observed on the surface of a polished steel specimen can be interpreted by tri-axial stress state with surface components of stress tensor
11(0)=
22(0) and gradientsg
11=
11/T, g
33=
33/T. The distribution of experimental values
is duscussed from the viewpoint of various ways of calculating
11.The authors would like to thank Dr. J. Musil, D. Sc. of the Institute of Physics of Czechoslovak Academy of Sciences for kindly providing the samples which made possible this study. 相似文献