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1.
The behavior of the magnetization M and the magnetic susceptibility χ is theoretically analyzed for ferromagnets at the temperature T=T m corresponding to the maximum of the function χ(T). Four new methods of determining the Curie temperature TC with the use of the derived relationships are proposed. One of these methods is based on the relationship χ(T m ) =21/3χ(TC) (the 21/3 rule). The results are applied for processing experimental data obtained for lanthanum manganite of composition La0.85Sr0.15MnO3. 相似文献
2.
A. G. Gavriliuk S. A. Kharlamova I. S. Lyubutin I. A. Troyan S. G. Ovchinnikov A. M. Potseluiko M. I. Eremets R. Boehler 《JETP Letters》2004,80(6):426-432
The optical properties and structure of gadolinium iron borate GdFe3(BO3)4 crystals are studied at high pressures produced in diamond-anvil cells. X-ray diffraction data obtained at a pressure of 25.6 GPa reveal a firstorder phase transition retaining the trigonal symmetry and increasing the unit cell volume by 8%. The equation of state is obtained and the compressibility of the crystal is estimated before and after the phase transition. The optical spectra reveal two electronic transitions at pressures ~26 GPa and ~43 GPa. Upon the first transition, the optical gap decreases jumpwise from 3.1 to ~2.25 eV. Upon the second transition at P=43 GPa, the optical gap deceases down to ~0.7 eV, demonstrating a dielectric-semiconductor transition. By using the theoretical model developed for a FeBO3 crystal and taking into account some structural analogs of these materials, the anomalies of the high-pressure optical spectra are explained. 相似文献
3.
E. A. Bogomolov G. I. Vasilyev W. Menn PAMELA Collaboration 《Physics of Atomic Nuclei》2018,81(3):390-395
Preliminary results of measurements of the solar modulation of the isotopic hydrogen and helium content in galactic cosmic rays are presented for the first time. These data were obtained between 2006 and 2014 in the PAMELA international orbital experiment via measuring the time of flight of nuclei in the Pamela scintillation telescope and via analyzing, in the multilayered calorimeter of the PAMELA magnetic spectrometer, ionization losses of nuclei whose rigidity was known from trajectory measurements and which traversed the instrument without undergoing nuclear interactions. The results of these measurements are compared with existing experimental and calculated data, which are quite scanty. 相似文献
4.
T. Shizuma T. Ishii H. Makii T. Hayakawa S. Shigematsu M. Matsuda E. Ideguchi Y. Zheng M. Liu T. Morikawa 《The European Physical Journal A - Hadrons and Nuclei》2007,32(1):1-4
In this paper we present for the first time the measured delayed neutron (DN) yields and time spectra from high-energy protons
interacting with thick natPb targets. The 1GeV protons from the accelerator impinged on targets of different thicknesses producing a huge number of
spallation-fission products, some of which can be DN precursors. After the beam is switched off, the DNs were detected with
optimized 3He counter. The production yields of light DN precursors as 17N and “usual” fission products as 87Br and 88Br, which dominate the total DN activity, are obtained both for thin and thick targets. These new data are of great interest
for the new generation high-power spallation targets based on liquid-metal technologies. Our findings also should help to
constrain the physics models within the simulations codes. 相似文献
5.
Within the framework of the single-channel approximation, an {αtd} model of the 9
Be nucleus is presented. A comparative analysis of the t 6
Li wave functions describing relative motion of bound states constructed in {ααn} and {αtd} cluster representations is carried out on the example of calculations of the 9
Be(γ,t0)6
Li process characteristics.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 85–89, January, 2008. 相似文献
6.
A. Heusler T. Faestermann R. Hertenberger R. Krücken H. -F. Wirth P. von Brentano 《The European Physical Journal A - Hadrons and Nuclei》2010,46(1):17-26
From 208Pb (p, p’) via isobaric analog resonances in 209Bi , at E
x = 6420 keV in the doubly magic nucleus 208Pb , a new state with spin 2- with half the s
1/2
p
3/2 strength and major g
7/2
f
5/2 , d
3/2
f
5/2 fractions is identified. Ten more 2- states up to E
x = 7.0 MeV are identified and their structure discussed, among them six states with new spin assignments. The known 6314 1- state is shown to contain almost the entire s
1/2
p
3/2 strength. 相似文献
7.
The nuclear spectroscopic quadrupole moments for the πh9/25/2-, 1/2-[541] and the πh11/29/2-, 9/2-[514] isomeric states in 169Ta have been measured employing the time differential perturbed angular-distribution technique following the nuclear reaction
159Tb(16O, 6nγ)169Ta at beam energy 104 MeV. The ratio of the intrinsic quadrupole moments
has been derived as 1.87(13) from the measured quadrupole precession frequencies of the corresponding states. The model-independent
analysis of the equilibrium deformation indicates strong prolate- and oblate-driving nature of the 1/2-[541] and 9/2-[514] orbitals in 169,171Ta isotopes, respectively. 相似文献
8.
9.
C. Chen B. C. Gou 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(3):545-550
The hyperfine structure parameters of the 1s22snp (n=2, 3) 3P states for the beryllium isoelectronic sequence from Z= 4 to 10 are calculated with the full-core plus correlation (FCPC)
wave functions. For the 1s22s2p 3P state of the beryllium atom, the calculated fine structure parameters are in good agreement with the latest theoretical
and experimental data in the literature. It is shown that hyperfine constants of the low-lying excited states for the beryllium
atom can be calculated accurately using this theoretical method. For 1s22snp (n=2, 3) 3P states of the beryllium isoelectronic sequence, our predictions may provide valuable reference data for other theoretical
calculations and experimental measurements in future. 相似文献
10.
T. Grahn J. Pakarinen L. Jokiniemi M. Albers K. Auranen C. Bauer C. Bernards A. Blazhev P. A. Butler S. Bönig A. Damyanova T. De Coster H. De Witte J. Elseviers L. P. Gaffney M. Huyse A. Herzáň U. Jakobsson R. Julin N. Kesteloot J. Konki Th. Kröll L. Lewandowski K. Moschner P. Peura M. Pfeiffer D. Radeck P. Rahkila E. Rapisarda P. Reiter K. Reynders M. Rudiger M. -D. Salsac S. Sambi M. Scheck M. Seidlitz B. Siebeck T. Steinbach S. Stolze J. Suhonen P. Thoele M. Thürauf N. Warr P. Van Duppen M. Venhart M. J. Vermeulen V. Werner M. Veselsky A. Vogt K. Wrzosek-Lipska M. Zielińska 《The European Physical Journal A - Hadrons and Nuclei》2016,52(11):340
11.
12.
Different momentum space Faddeev-like equations and their solutions for the radiative pd-capture and the three-nucleon photodisintegration of 3He are presented. Applications are based on the AV18 nucleon-nucleon and the Urbana IX three-nucleon forces. Meson exchange currents are included using the Siegert theorem. A very good agreement has been found in all cases indicating the reliability of the used numerical methods. Predictions for cross-sections and polarization observables in the pd-capture and the complete three-nucleon breakup of 3He at different incoming-deuteron/photon energies are presented. 相似文献
13.
J. F. Sharpey-Schafer T. E. Madiba S. P. Bvumbi E. A. Lawrie J. J. Lawrie A. Minkova S. M. Mullins P. Papka D. G. Roux J. Timár 《The European Physical Journal A - Hadrons and Nuclei》2011,47(1):6
The concept that the first excited 0+ states in N = 90 nuclei are not a b \beta -vibration but a second vacuum formed by the combination of the quadrupole pairing force and the low density of oblate orbitals
near the Fermi surface is supported by the blocking of this collective mode in 154Gd from coupling to the [505]11/2- single-particle quasi-neutron orbital in 155Gd . The coupling of this orbital to the 2+
g \gamma -vibration in 154Gd is observed since this coupling is not Pauli-blocked. 相似文献
14.
P. Masłowski J. Domysławska K. Bielska R. Ciuryło D. Lisak R. S. Trawiński J. Szudy 《The European physical journal. Special topics》2007,144(1):239-242
Experimental results of a systematic study of profiles of the
hyperfine-structure components of the intercombination 51S0 – 5 3P1 line of
the even-odd 113Cd isotope perturbed by argon performed by means of a
laser-induced fluorescence method are reported. We have found that the values
of total line asymmetries of both hfs line components are different. 相似文献
15.
I. Sherstov S. Liu Ch. Lisdat H. Schnatz S. Jung H. Knöckel E. Tiemann 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(3):485-492
Absolute transition frequencies of the b 3Π(0u
+) - X 1Σg
+ system of K2 were measured in a molecular beam with Lamb dip absorption spectroscopy applying a frequency comb from a femtosecond pulsed
laser. Both, K atoms and K2 molecules are present in the beam and are expected to interact by collisions. The atoms can be deflected optically out of
the beam, and thus the collision rate between K atoms and K2 molecules is changed by about an order of magnitude. The molecular transition frequencies for low collisional rate are compared
with those for high one. Limits for the collisional frequency shift within the beam are determined. 相似文献
16.
The vibration frequencies of unstable ferroelectric and antiferrodistortion modes and the dependences of the energy on the
ion displacement amplitude have been calculated within the generalized Gordon-Kim model for distortions along eigenvectors
of these modes in the mixed compounds Sr1 − x
A
x
Ti1 − x
/4□
x/4O3 and Sr1 − y
A
2y
/3□
y/3TiO3 (A = Sc3+, In3+, La3+, Bi3+; □ is the vacancy). To compensate an excess positive charge, vacancies are introduced into the Ti4+ or Sr2+ site. Calculations have been performed in the “daverage” crystal approximation for impurity concentrations of 0.25 and 0.50.
To this end, a set of 40 atomic superlattices with various orderings of heterovalent ions Sr2+ and impurity A
3+ has been considered. It has been found that each impurity type, independently of charge balance, induces ferroelectric instabilities
in doped compounds. In the case of doping with In3+ and La3+ for concentration x = 0.25, the possibility of rotating the polarization vector has been shown. 相似文献
17.
E. V. Schmidt V. L. Ermakov O. I. Gnezdilov V. L. Matukhin B. V. Korzun A. A. Fadeeva I. Kh. Khabibullina 《Journal of Applied Spectroscopy》2009,76(5):667-671
Results of studies of non-stoichiometric CuInS2 semiconductor by 63Cu and 115In nuclear magnetic resonance are presented. It was established that deviation of the composition from stoichiometry causes
a quadrupolebroadened region of the NMR spectrum to change most. In this case a central peak whose shape is governed by the
chemical shift anisotropy remains unaffected. NMR spectra reveal two types of structural distortions in the nearest surroundings
of the In atoms. 相似文献
18.
We revisit the B+→X(3872)+K+ in the pQCD approach assigning to X(3872) a 23P1 charmonium state. In this theoretical framework all the phenomenological parameters in the wavefunctions and Sudakov factor
are a priori fixed by fitting other experimental data; therefore, there hardly are any free parameters in the whole numerical
computations. Our results are larger than the upper bound set by the BABAR measurements.
PACS 13.20.He; 12.38.Bx; 13.60.Le 相似文献
19.
M. A. Kalyar S. Mahmood S.-U. Haq N. Amin M. A. Baig 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(2):229-236
We report a systematic line shape analysis study of the 6p7p configuration
based 1P1, 3D1 and 3P1 autoionizing
resonances in barium using a Nd:YAG pumped dye laser system in conjunction
with a thermionic diode ion detector. The even parity isolated autoionizing
resonances have been approached via four intermediate states 6 snp
1P1 (6 ≤n ≤8) and 5d6p 1P1. A comparison of
the Fano parameters of the resonance profiles reveals that the width of an
autoionizing resonance is independent of the excitation path while the line
profile parameter changes with the selection of different intermediate
states. 相似文献
20.
G. E. Volovik 《JETP Letters》2010,91(4):201-205
The topological superfluid 3He-B provides many examples of the interplay of symmetry and topology. Here we consider the effect of magnetic field on topological
properties of 3He-B. Magnetic field violates the time reversal symmetry. As a result, the topological invariant supported by this symmetry
ceases to exist; and thus the gapless fermions on the surface of 3He-B are not protected any more by topology: they become fully gapped. Nevertheless, if perturbation of symmetry is small,
the surface fermions remain relativistic with mass proportional to symmetry violating perturbation—magnetic field. The 3He-B symmetry gives rise to the Ising variable I = ±1, which emerges in magnetic field and which characterizes the states of the surface of 3He-B. This variable also determines the sign of the mass term of surface fermions and the topological invariant describing
their effective Hamiltonian. The line on the surface, which separates the surface domains with different I, contains 1 + 1 gapless fermions, which are protected by combined action of symmetry and topology. 相似文献