<Emphasis Type="Italic">FCC/BCC</Emphasis> competition and enhancement of saturation magnetization in nanocrystalline Co-Ni-Fe films

The structure, chemical composition, and magnetic properties of electrochemically deposited nanocrystalline Co-Ni-Fe films were investigated using a number of techniques. A high saturation magnetic induction up to B _s = 21 kG was attained. An enhancement of the saturation magnetization compared to the ideal anticipated one was revealed, which correlated with the nonlinear behavior of the structural phase composition and lattice parameters with the change of the composition. The text was submitted by the authors in English.     

Preparation of 3-substituted and 2,3-disubstituted-4,4,4-trifluoro-2-butenoic acids—Perkin condensation of activated aromatic ketones

The Perkin reaction of the activated aromatic ketones (2,2,2-trifluoroacetophenone and its 4′-phenyl-derivative) with various condensing agents (acetic anhydride, propionic anhydride, phenylacetic acid/acetic anhydride) gives the title compounds in good or moderate yields, and high E-stereoselectivity. For some derivatives an appreciable amount of the Z isomer was also formed. Several of the resulting butenoic acids and their methyl esters are synthesised and characterised for the first time.     

Spectral boundary controllability of networks of strings

In this Note we give a necessary and sufficient condition for the spectral controllability from one simple node of a general network of strings that undergoes transversal vibrations in a sufficiently large time. This condition asserts that no eigenfunction vanishes identically on the string that contains the controlled node. The proof combines the Beurling–Malliavin's theorem and an asymptotic formula for the eigenvalues of the network. The optimal control time may be characterized as twice the sum of the lengths of all the strings of the network. To cite this article: R. Dáger, E. Zuazua, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 545–550.     

Dynamic study of gated saturable absorbers

The capability of gated saturable absorbers for single-pulse selection is studied theoretically using the classical space-time-dependent rate-equation model. The dynamics of operation is followed experimentally by the well-known pump—probe technique. Comparing the theoretical and experimental results, it is found that gated saturable absorbers can efficiently be used for pulse forming and pulse selection of pulses longer than picosecond.     

Forecasting call frequency at a financial services call centre

A forecasting model is developed for the number of daily applications for loans at a financial services telephone call centre. The purpose of the forecasts and the associated prediction intervals is to provide effective staffing policies within the call centre. The model building process is constrained by the availability of only 2 years and 7 months of data. The distinctive feature of the data is that demand is driven in the main by advertising. The analysis given focuses on applications stimulated by press advertising. Unlike previous analyses of broadly similar data, where ARIMA models were used, a model with a dynamic level, multiplicative calendar effects and a multiplicative advertising response is developed and shown to be effective.