The experimental rotational spectra of the deformed nuclei available in even-even and odd-A nuclei in the rare-earth and actinide regions are systematically analyzed with several rotational spectra formulas, including Bohr-Mottelson＇s I（I＋ 1）-expansion, Harris＇ ω^2-expansion, ab and abc formulas. It is shown that the simple 2-parameter ab formula is much better than the widely used 2-parameter Bohr-Mottelson＇s AB formula and Harris＇ αβ formula. The available data of the rotational spectra of both ground-state band in even-even nuclei and one-quasiparticle band in odd-A nuclei can be conveniently and rather accurately reproduced by ab formula and abc formula. The moment of inertia and the variation with rotational frequency of angular momentum can be satisfactorily reproduced by ab and abc formulas.
Sanchez and Lacombe have developed a lattice fluid theory based on a well-defined statistical mechanical model.Taking the lattice fluid as a candidate of dark energy,we investigate the cosmic evolution of this fluid.Using the combined observational data of Type Ia Supernova(SNe Ia) Union2.1,Baryon Acoustic Oscillations(BAO) data from 6dFGS,SDSS and WiggleZ survey,and Observational Hubble Data(OHD),we find the best fit value of the parameters:A = 0.3 ± 0.2(1σ) ± 0.4(2σ) ± 0.8(3σ) and Ω m = 0.31 ± 0.02(1σ) ± 0.05(2σ) ± 0.07(3σ).The cosmological implications of the model are presented.
