Energy levels of Nd(IV) and Er(IV) in Y2O3

1969 ◽  
Vol 47 (24) ◽  
pp. 2753-2761 ◽  
Author(s):  
P. A. Narayana

The free-ion energy levels of Nd(IV) and Er(IV) in Y2O3 are expanded in a Taylor series, taking the effects of both linear and nonlinear configurational interactions into account. Numerical values of the partial derivatives of the energy levels with respect to F2, F4, F6, ξ, α, β, Y(22,1), and Y(22,3) are tabulated. The r.m.s. deviation in the case of Nd(IV) is improved from 90 cm−1 to 48 cm−1 and, in the case of Er(IV), the r.m.s. deviation is improved from 61.5 cm−1 to 43 cm−1. The improvements are the result of the inclusion of the extra parameters.

1993 ◽  
Vol 193 (1-2) ◽  
pp. 203-206 ◽  
Author(s):  
C.K. Jayasankar ◽  
A. Renuka Devi ◽  
E. Rukmini ◽  
M.F. Reid

Author(s):  
Mihaela-Ligia M. Unguresan ◽  
Delia Maria Gligor ◽  
Francisc Dulf ◽  
Tiberiu Colosi

The paper presents the dispersion of the concentration y(t, s) on the length (s) with respect to time (t), corresponding to the adsorption process of a phenothiazine derivative on graphite electrodes. The numerical simulation by equations with partial derivatives of the second order with two independent variables (t and s) (PDE II.2), based on (Mpdx) which associates with Taylor series was performed. Also, the adsorption process defined by PDE II.2 was included in a regulation scheme of concentration y(t, s) with multiple freedom levels. It insures good performances and a remarkable flexibility for extending the method in similar categories of applications.


Author(s):  
Ruifei Peng ◽  
Haitian Yang ◽  
Yanni Xue

A package solution is presented for the full-scale bounds estimation of temperature in the nonlinear transient heat transfer problems with small or large uncertainties. When the interval scale is relatively small, an efficient Taylor series expansion-based bounds estimation of temperature is stressed on the acquirement of first and second-order derivatives of temperature with high fidelity. When the interval scale is relatively large, an optimization-based approach in conjunction with a dimension-adaptive sparse grid (DSG) surrogate is developed for the bounds estimation of temperature, and the heavy computational burden of repeated deterministic solutions of nonlinear transient heat transfer problems can be efficiently alleviated by the DSG surrogate. A temporally piecewise adaptive algorithm with high fidelity is employed to gain the deterministic solution of temperature, and is further developed for recursive adaptive computing of the first and second-order derivatives of temperature. Therefore, the implementation of Taylor series expansion and the construction of DSG surrogate are underpinned by a reliable numerical platform. The parallelization is utilized for the construction of DSG surrogate for further acceleration. The accuracy and efficiency of the proposed approaches are demonstrated by two numerical examples.


1993 ◽  
Vol 316 ◽  
Author(s):  
J. Ullmann ◽  
A. Weber ◽  
U. Falke

ABSTRACTFor a deeper understanding of the creation of carbon films the hydrogen-free ion assisted evaporation (IAE) method with neon species was used. Variation of the ion parameters energy and ion to neutral arrival ratio, delivering the necessary energy for modification of the film growth, results in different microstructures investigated with EELS, HRTEM and TED as well as different microhardnesses measured by dynamical Vickers indentation. A possible film growth mechanism is proposed based on an ion etching of mainly sp2-bonded carbon surface atoms and on defect dominated structure modification below the surface depending on the ion energy


Author(s):  
Nitin Arora ◽  
Ryan P. Russell ◽  
Nathan J. Strange

1968 ◽  
Vol 5 (2) ◽  
pp. 401-413 ◽  
Author(s):  
Paul J. Schweitzer

A perturbation formalism is presented which shows how the stationary distribution and fundamental matrix of a Markov chain containing a single irreducible set of states change as the transition probabilities vary. Expressions are given for the partial derivatives of the stationary distribution and fundamental matrix with respect to the transition probabilities. Semi-group properties of the generators of transformations from one Markov chain to another are investigated. It is shown that a perturbation formalism exists in the multiple subchain case if and only if the change in the transition probabilities does not alter the number of, or intermix the various subchains. The formalism is presented when this condition is satisfied.


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