Ternary complexes of some rare earth metal ions with 1,2-diaminocyclohexanetetraacetic acid and hydroxy acids

1:1:1, Rare earth ions-CDTA-hydroxy acids ternary systems have been studied pH-metrically. The formation constants (log K_MLL′) and free energies of formation (ΔF°) of the resulting octa-coordinated metal ion mixed-ligand complexes have been calculated. The order of stability in terms of metal ions has been reported as: La < Pr < Nd < Gd < Dy and in terms of hydroxy acids as: TAR < MAL.     

Analytic Calculation of Neutrino Mass Eigenvalues

Implication of the neutrino oscillation search for the neutrino mass square difference and mixing are discussed. We have considered the effective Majorana mass m _ee , related for ββ _0ν decay. We find limits for neutrino mass eigen value m _i in the different neutrino mass spectrum,which explain the different neutrino data.     

Double k-Class Estimators in Regression Models with Non-spherical Disturbances

In this paper, we consider a family of feasible generalised double k-class estimators in a linear regression model with non-spherical disturbances. We derive the large sample asymptotic distribution of the proposed family of estimators and compare its performance with the feasible generalized least squares and Stein-rule estimators using the mean squared error matrix and risk under quadratic loss criteria. A Monte-Carlo experiment investigates the finite sample behaviour of the proposed family of estimators.     

Oscillating Neutrino Mass States and Double Beta Decay

Physics of Atomic Nuclei - Neutrino oscillation is an experimentally established phenomenon by which neutrinos undergo flavor transformations periodically as they propagate large enough distances....     

Random-walk theory for localization

A continuous-time random-walk theory has been developed for Anderson localization. On a continuous time scale random walks are performed along extended (i.e., propagating) and localized (i.e., trap) states. Complete information of disorder is contained in a distribution function called “hopping time distribution function” ψ_nm(t), which gives the probability per unit time for transition from state m to state n in time t. The “stay-put” probability ??(t = ∞), which is the probability to rediscover an excitation at a site “0” at time t = ∞ if it was there at t = 0, is obtained in terms of ψ_nm(t). Appropriate forms for ψ_nm(t) are constructed which are in conformity with the photoconductivity experiments on dispersive transport, and ??(∞) are calculated. The results indicate that the entire spectrum consists of three regimes, namely, those of (i) “diffusion,” (ii) “weak diffusion,” and (iii) “no diffusion,” which, respectively, designate the extension, the power-law localization, and the exponential localization of states. The results also shed light on the question of “continuous or discontinuous (?)” transition across the mobility edge.     

The biosynthesis of nornuciferine-I(2-methoxy-6aα-aporphine-1-ol)

The incorporation of (±)-norcoclaurine, (±)-coclaurine, (±)-N-methylcoclairine, (±)-N-methylnorcoclaurine into nornuciferine-I in Croton sparsiflorus morong has been studied, and the specific utilization of the (±)-N-methylcoclaurine demonstrated. The evidence supports the direct oxidative coupling of (+)-(S)-N-methylcoclaurine to give N-methylcrotsparine, which in turn is shown to be a specific precursor of nornuciferine-I. The experiments also show that N-methylcrotsparine is reduced to N-methylcrotsparinol and it is N-methylcrotsparinol-I which is preferentially dehydrated and rearranged to nornuciferine-I.     

Fcc-hcp phase coexistence in Al at high pressures: Explanation in terms of density of states

The density of states (DOS) of fcc and hcp structures of Al has been calculated for normal and high pressures. It has been found that the DOS of both structures, near the Fermi level, is similar over a range of compressed volumes close to the fcc-hcp transition volume (V/V₀∼0.53). This similarity is the reason for the reported coexistence of fcc-hcp phases over a wide range of pressures near the fcc-hcp phase transition. All calculations have been performed using the FP-LAPW method with GGA.     

Experiment aimed at the study of 252Cf binary and ternary fission

A new experiment devoted to the fission of ²⁵²Cf is described. It continued a series of our experiments based on correlation measurements of γ rays emitted by fission fragment pairs. The measurements of γ-γ and γ-γ-γ coincidences were done at Gammasphere with closed ²⁵²Cf sources. The open source was used for the first time in the last experiment. Fission fragment detectors were arranged in the center hole of Gammasphere. Correlations between fission fragment masses, total kinetic energy, and γ rays were observed. The first, preliminary results of data analysis are discussed. The text was submitted by the authors in English.     

Capacity and entry issues in online exchanges

With the advent of open standards and Internet technologies, the number of sellers who can participate in online exchanges is greatly increased. We model the competition between identical sellers vying for the same business, and find that there exists a mixed-strategy equilibrium in prices. The results help us understand the dynamics between a seller’s capacity and his motivation to participate in an auction.