共查询到19条相似文献,搜索用时 171 毫秒
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用Seyler-Blanchard动量相关非定域相互作用的含温Thomas-Fermi统计理论,对半无穷大核物质模型计算了核物质表面能系数σ(T,δ)随温度T和不对称度δ的变化,发现在低温T≤5MeV和不对称度δ≤0.2时,可以近似写成σ(T,δ)=σ0(T)[1+K(T)δ2],其中σ0(T)和K(T)可以拟合成温度T的二次函数. 相似文献
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The implications of the f1(1285)-f1(1420) mixing for the K1(3P1)- K1(1P1) mixing angle are investigated. Based on the f1(1285)-f1(1420) mixing angle ∼ 50° suggested from the analysis for a substantial body of data concerning the f1(1420) and f1(1285), the masses of the K1(3P1) and K1(1P1) are determined to be ∼ 1307.35±0.63 MeV and 1370.03±9.69 MeV, respectively, which therefore suggests that the K1(3P1)- K1(1P1) mixing angle is about ±(59.55±2.81)°. Also, it is found that the mass of the h′1(1P1) (mostly of sˉ) state is about 1495.18±8.82 MeV. Comparison of the predicted results and the available experimental information of the
h1(1380) shows that without further confirmation on the h1(1380), the assignment of the h1(1380) as the sˉ member of the 1P1 meson nonet may be premature. 相似文献
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一种新型的两态叠加MSCS光场的广义非线性等阶N次方H压缩 总被引:41,自引:28,他引:13
本文利用新近建立的多模压缩态理论,详细研究了一种新型的两态叠加多模薛定谔猫态(即MSCS)光场|ψ(2)〉q的广义非线性等阶N次方H压缩效应.结果发现:1态|ψ(2)〉q是一种典型的非经典光场;当压缩阶数N与腔模总数q这两者之积为偶数,即qN=2p,并且p为奇数亦即p=2m’+1(m’=0,1,2,3,…,…)时,如果各模的初始相位和∑j=1qψj态间的初始相位差(θpq(I)-θnq(R))、各多模相干态光场的总的平均光子数∑j=1qRj2等满足一定的量子化条件(或者当∑j=1qRj2在总的平均光子数∑j=1qRj2的一系列压缩区内连续取值时),态|ψ(2)〉q总可呈现出周期性变化的、任意阶的广义非线性等阶N次方H压缩效应.2态|ψ(2)〉q的第一及第二两个正交分量,其压缩结果(亦即压缩程度和压缩深度)完全相同,但压缩条件不同;两者的等阶N次方H压缩效应呈现出周期性的互补关系.3与文献16相比,本文所研究的态|ψ(2)〉q的等阶N次方H压缩效应是比其等阶N次方Y压缩效应更高阶的广义非线性等阶高阶压缩效应. 相似文献
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Angular dependences of 9Be NMR (±1/2) and (±1/2 ? ±3/20 transition frequencies are measured in a single-crystal beryllium metal plate in a field of 7.04T. The isotropic K iso and anisotropic K aniso components of the Knight shift are determined. The measured values of K iso and T 1 are considered in terms of the contact, polarization, and orbital contributions. 相似文献
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A scheme for a nonlocal theory of quantized fields based on the hypothesis of stochastic space is proposed. Within this scheme the gauge-invariant quantum electrodynamics of particles with spin 0, 1/2, 1 and four-fermion weak interactions are constructed, and nonlocal corrections to the anomalous magnetic moments of leptons and to the Lamb shift are calculated. Some consequences of the neutrino oscillations and the electromagnetic properties of neutrinos are considered in detail. Further the rare decayK L 0 →Μ+Μ? and the mass difference ofK L 0 andK S 0 mesons are investigated in this model. It is shown that the parameter of nonlocality (elementary lengthl) of weak interactions which can characterize a domain of unification of weak and electromagnetic interactions is ~10?16 cm. The low-energy experiments imply that quantum electrodynamics is valid up to distances of order ~10?15 cm. 相似文献
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V. P. Gavrilin V. M. Mitlin L. I. Koshkin Yu. A. Bratashevskii N. N. Pafomov 《Russian Physics Journal》1973,16(8):1134-1137
A study of crystallographic and uniaxial anisotropy in monocrystalline Li-ferrite films in the temperature range 4.2–550°K is presented. The experimental results K1(T) agree well with calculations based on the one ion model with crystalline field coefficients of aA=–2.77 ·10–2 cm–1, aB=3.34 · 10–2 cm–1. An experimental function Ku(T) is obtained which does not contradict the assumption that anisotropic stresses are responsible for the development of uniaxial anisotropy in Li-ferrite films.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 113–116, August, 1973. 相似文献
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F.K. Lotgering 《Journal of Physics and Chemistry of Solids》1974,35(12):1633-1639
The saturation magnetization σs and uniaxial anisotropy constants K1 and K2 are measured on a polycrystalline, crystal-oriented sample of LaFe12O19 contaminated with known amounts of Fe3O4 and LaFeO3. K1 and K2 increase strongly with decreasing temperature and the value of K1 = (19–24) × 105 erg/g at T = 0 shows that the substance is considerably more anisotropic than BaFe12O19 (K1 ? 8·5 × 105 erg/g) at low temperatures. The σs-T curve is more convex than that of BaFe12O19, so that σs is 11 per cent higher at room temperature but lower at T = 0. The value σs(T = 0) = 96·2 G cm3/g (19·2 μB/molecule) and the anisotropic behaviour are attributed to the presence of 1 Fe2+/molecule occupying the octahedral 2a sites in the magnetoplumbite lattice and having a uniaxial anisotropy of 10–15 cm?1/ion.From measurements on polycrystalline, crystal-oriented samples of BaFe10·8Fe2+0·6Ti4+0·6O19 and BaFe10·5Fe2+1·0Sb5+0·5O19 it was found that, in comparison with LaFe11Fe2+O19, σs (T = 0) is smaller and K1 is much smaller and much less temperature-dependent. The difference in anisotropic behaviour is attributed to a different distribution of the Fe2+ ions among the lattice sites due to the effective positive charge of the Ti4+ and Sb5+ ions. 相似文献
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M. Zelený 《Czechoslovak Journal of Physics》1976,26(10):1174-1178
Conclusion The change from the zero to the first approximations is accompanied by the change of the sign ofK
1,K
2
1
being of the same order asK
1
1
. It implies that the neglection of further members of the expansion in (2) may not be quite right. Therefore it might be better to take into consideration also the effect of the further members in (5), but in such a case equation (7) would contain so many unknown parametersK
i
j
, that another way how to solve it would be necessary. In our case, (7) is an equation of a tangent to the curveK
1
0
=f(1–x
2) at const.H, which has enabled us to determine the dependencesK
1
1
(T, H) andK
2
1
(T, H). Generally, there are other methods of studying the parametersK
i
j
(based on the analysis of torque curves for example) which are more suitable in similar cases, but these methods usually allow necessary measurements only in the fields considerably less than those used in [5]. 相似文献
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The defect (Mn2+,Ni2+,Fe2+) induced magnon gap modes in the layered antiferromagnets K2CoF4 and Rb2CoF4 were investigated with the methods of FIR absorption-and IR emission spectroscopy. The anisotropic exchange-parameters describing the strongly localized Mn2+ spin excitations far below the host lattice magnon band and the Ni2+ excitations in the vacinity of this band are presented. In the diluted system K2Co1-cMncF4 localized Mn2+ cluster modes up to about C≈0.1 were observed. The excitation energy of these modes can only be explained by assuming an anisotropic Mn2+-Mn2+ exchange which is in contrast to the pure isomorphous system K2MnF4. In the spin mismatch system K2CoF4: Fe the magnetic moments of the isolated Fe2+ impurities are pulled from the plane perpendicular to the c-axis and aligned parallel to the easy axis of the magnetic crystal. 相似文献
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Yu.P. Malakian 《Nuclear Physics B》1978,133(1):145-156
Weak radiative decays KL → 2γ and KL → π+π?γ are considered in the Weinberg-Salam model for weak interactions and in the framework of asymptotically free gauge theory (AFGT) for strong interactions (SI). The problem of calculation of the decays at short and large distances is discussed. It is shown that only the large distance contribution is essential for each decay. The estimates of these contributions being rough, it proves impossible to compare them with experiment. However, using anomalous PCAC theory we derive the relation connecting the contributions for these two decays and, hence, the decay amplitudes via the known constants. Experimental data confirm the obtained result. The important result of the paper is that the matrix elements of the effective Hamiltonian specifying the decays at short distances are not dynamically enhanced, unlike the case of weak non-leptonic amplitudes. 相似文献
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We discuss the nature of the pairing mechanism and the physical properties associated with the normal as well as the superconducting state of cubic perovskites Ba0.6K0.4BiO3using the strong coupling theory. An interaction potential which includes the Coulomb, electron–optical phonon and electron–plasmon interactions is developed to elucidate the superconducting state. A model dielectric function is constructed with these interactions fulfilling thef-sum rule. The screening parameter (μ* = 0.26) infers the poor screening of charge carriers. The electron–optical phonon strength (λ) estimated as 0.98 is consistent with an attractive electron–electron interaction and supports the moderate to strong coupling theory. The superconducting transition temperature of Ba0.6K0.4BiO3is then estimated as 32 K. Ziman's formula of resistivity is employed to analyse and compare this with the temperature-dependent resistivity of a single crystal. The estimated contribution from the electron–optical phonon together with the residual resistivity clearly infers a difference when a comparison is made with experimental data. The subtracted data infer a quadratic temperature dependence in the temperature domain (30 ≤ T ≤ 200 K). The quadratic temperature dependence of ρ [ = ρexp − (ρ0 + ρe–ph)] is understood in terms of 3D electron–electron inelastic scattering. The presence of these el–el and el–ph interactions allows a coherent interpretation of the physical properties. Analysis reveals that a moderate to strong coupling exists in the Ba0.6K0.4BiO3system and the coupling of electrons with the high-energy optical phonons of the oxygen breathing mode will be a reason for superconductivity. The implications of the above analysis are discussed. 相似文献
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The ν1 (A1, 1583.22 cm−1) and ν4 (E, 1615.33 cm−1) Si-D stretching bands of monoisotopic D3Si35Cl have been studied by FTIR spectroscopy with a resolution of 3.3×10−3 cm−1. We have assigned 2341 rovibrational lines for ν1 (Jmax=70, Kmax=19) and 6207 for ν4 (Jmax=75, Kmax=27). Both (ΔK=±1, Δ?=±1) and (ΔK=±2, Δ?=?1) interactions connect the v1=1 and v4=1 levels, the latter exerting moreover a weak ?(2, 2) interaction. These interactions were taken into account in a nonlinear least-squares fit, refining 29 free parameters with a standard deviation of 0.257×10−3 cm−1 over 6722 nonzero-weighted data. Blended lines and about 250 of the 330 lines belonging to the K=11 subband of ν1 and the KΔK=−6 subband of ν4 were zero-weighted because they are locally perturbed respectively by the neighboring upper states of the 2ν3+ν6 (E, 1561.95 cm−1) and 3ν3 (A1, 1604.81 cm−1) bands. Equivalent fits were obtained for altogether three different models obeying constraints according to the theory of unitary equivalent reductions of the rovibrational Hamiltonian. By means of a band contour simulation both the transition moment ratio |M1:M4|=0.67 and a positive sign of the Coriolis intensity perturbation were determined. 相似文献