New results in subdifferential calculus with applications to convex optimization

Chain and addition rules of subdifferential calculus are revisited in the paper and new proofs, providing local necessary and sufficient conditions for their validity, are presented. A new product rule pertaining to the composition of a convex functional and a Young function is also established and applied to obtain a proof of Kuhn-Tucker conditions in convex optimization under minimal assumptions on the data. Applications to plasticity theory are briefly outlined in the concluding remarks.The financial support of the Italian Ministry for University and Scientific and Technological Research is gratefully acknowledged.     

Generalized Schur-Coleski factorization with applications to image processing

A special type of factorization for operators defined on partially ordered Hilbert resolution spaces is considered. The main result includes, as a particular case, the classical Schur-Coleski triangular factorization. Connections with stochastic optimization and image-processing problems are established.This research was sponsored in part under NSF grant 78/88/71, AFOSR grant 78-3500 and Canadian Research Council grant CNRC-A-8244.     

Reaction of vinylcyclopropanes with butyllithium

Vinylcyclopropanes III and IV gave mainly allyl anions I, II, and XIII respectively under strong metalating conditions. Cyclopropyllithiums V and XV were also formed unexpectedly in significant quantities and were further explored.     

Experimental study of the reaction νμ + e− → μ− + νe

The first observation of the reaction ν_μ + e^? → μ^? + ν_e has been made in the bubble chamber Gargamelle exposed to the CERN SPS wide-band neutrino beam. A signal of 26 ± 6 events has been found. This is 0.90 ± 0.20 times the prediction of the V - A theory.     

Preparation and characterization of sintered pellets and «Thick» films of Bi2Sr2Y x Ca1−x Cu2O8

Il Nuovo Cimento D - A systematic study of yttrium substitution for calcium in the high-temperature superconductor Bi2Sr2CaCu2O8 compound has been performed. The samples of Bi2Sr2Y x Ca1−x...     

A time-domain algorithm for NMR spectral normalization

Recently, a new method for quantitatively comparing NMR spectra of control and treated samples, in order to examine the possible occurring variations in cell metabolism and/or structure in response to numerous physical, chemical, and biological agents, was proposed. This method is based upon the utilization of the maximum superposition normalization algorithm (MaSNAl) operative in the frequency domain and based upon maximizing, by an opportune sign variable measure, the spectral region in which control and treated spectra are superimposed. Although the frequency-domain MaSNAl algorithm was very precise in normalizing spectra, it showed some limitations in relation to the signal-to-noise ratio and to the degree of diversity of the two spectra being analyzed. In particular, it can rarely be applied to spectra with a small number of visible signals not buried in the noise such as generally in vivo spectra. In this paper, a time-domain normalization algorithm is presented. Specifically, it consists in minimizing the rank of a Hankel matrix constructed with the difference of the two free induction decay signals. The algorithm, denoted MiRaNAl (minimum rank normalization algorithm), was tested by Monte Carlo simulations as well as experimentally by comparing two samples of known contents both with the new algorithms and with an older method using a standard. Finally, the algorithm was applied to real spectra of cell samples showing how it can be used to obtain qualitative and quantitative biological information.     

First hint on a change of the 210Po alpha-decay half-life in the metal Cu

In the metal Cu cooled to T = 12K the α-decay half-life of ²¹⁰Po nuclides, located inside the metal, was measured to be shorter by 6.3±1.4% compared to that at room temperature.     

Pulsed laser photodeposition of a-Se nanofilms by ArF laser

Pulsed laser photodeposition from amorphous selenium aqueous colloid solutions using ArF laser radiation at a wavelength of λ = 193 nm has been investigated. Nanometer thick layers were obtained on UV transparent silica substrates in contact with the solution for various photodeposition parameters. Amorphous Se layers, 20 nm thick, were obtained typically by 40 laser pulses of 30 ns duration with a fluence of 50 mJ/cm². Deposition thresholds for depositing 1 nm thick layers were as low as 5 pulses. The deposited nanometer thin surface morphology was analyzed by Evanescent Field Optical Microscopy, Scanning Electron Microscopy and Atomic Force Microscopy. The nanometer thicknesses were evaluated by utilizing the differential evanescent light pattern emanating from the substrates.