Three-body final state breakup in the27Al(14N,X) reaction at 116 MeV bombarding energy

The energy spectra and angular distributions of products in the reaction²⁷Al(¹⁴N,X) have been measured at 116 MeV bombarding energy. It is shown that the energy spectra of the products lighter than the projectile, are well described by a three-body breakup calculation. The experimental total breakup cross-section estimated in the present work, together with Glas-Mosel calculation of the fusion cross-section, are in a reasonable agreement with the optical model total reaction cross-section.     

High resolution NMR spectroscopy of heteroaromatic cations. II—pyrylium,thiapyrylium and seleninium cations

The barriers to internal rotation about the C? N bond in several thiopiperidides have been determined by the NMR technique. It was found that the barrier height (ΔG^?) increases in the series cinnamoylthiopiperidide<thiobenzoylpiperidide<phenylthioacetylpiperidide. This trend was discussed in terms of the electronic structure, using HMO calculations. For m-and p-substituted cinnamoylthiopiperidides the barriers were shown to increase with the electron withdrawing character of the substituent in the aromatic ring.     

Riemannian manifolds carrying a pair of skew symmetric conformal vector fields

We deal with a Riemannian manifoldM carrying a pair of skew symmetric conformal vector fields (X, Y). The existence of such a pairing is determined by an exterior differential system in involution (in the sense of Cartan). In this case,M is foliated by 3-dimensional totally geodesic submanifolds. Additional geometric properties are proved. Supported by a JSPS postdoctoral fellowship.     

Higher valency ion substitution into the manganese oxide framework

A new route for higher valency ion substitution into the manganese oxide (OMS-2) framework is reported. Isomorphously substituted vanadium and niobium OMS-2 were hydrothermally synthesized at 200 degrees C for a period of 2 days. Characterization by XRD, elemental analysis, Raman spectroscopy, and resistivity studies proved that vanadium was incorporated into the manganese oxide structure. The presence of vanadium in the framework changes the electrical properties, making the material very attractive for water sensing applications.     

Numerical predictions and experiments on the free-plate edge mode

In this paper, te edge mode variation is studied with three different methods: the reciprocal work method, already used by Torvik [J. Acoust. Soc. Am. 41 (1967) 346] to model this phenomenon, the S-parameter method and a finite element model that are applied for the first time to the study of the edge resonance. Moreover, laser probe measurements of the edge mode have also been performed and compared to the numerical predictions. The good agreement between the numerical predictions and the experimental data allows full understanding of the resonant phenomenon. The edge resonance is linked to the strong increase in amplitude of two complex Lamb waves, and the edge mode is proved to radiate into the plate as the first symmetrical Lamb mode S(0). Displacements at the edge and away from the edge have been computed and measured to evaluate the spatial and temporal behaviour of the edge mode. The dependence of the edge resonance frequency and amplitude on the Poisson coefficient has also been studied.     

Optical bistability in axially modulated OmniGuide fibers

We demonstrate the feasibility of optical bistability in an axially modulated nonlinear OmniGuide fiber through analytical theory and detailed numerical experiments. At 1.55-microm carrier wavelength, the in-fiber devices that we propose can operate with only a few tens of milliwatts of power, can have a nearly instantaneous response and recovery time, and can be shorter than 100 microm.     

Temperature field distribution in multi-layered solid media heated with multi-modes laser beam

In the present paper we want to develop an analytical model to study the thermal behavior of multi-layered solid media in interaction with a laser beam. We suppose that each layer has a constant thermal conductivity. We consider that the laser beam is formed by decoupled [Phys Rev A 1996; 53: 4435] multi-modes Hermite–Gauss beams. The model is applied using the classical heat equation which was solved using the integral transform method [Infrared Phys Technol 2002; 42: 31; Optics Laser Technol 2004; 36: 219–22; Optics Laser Technol 2004; 36: 677–9; Proc SPIE 2003; 5227: 323].     

Thermal degradation behavior of some ruthenium complexes with fluoroquinolone derivatives as potential antitumor agents

Three new complexes with ligands belong to the fluoroquinolone class having the general formula [RuL₂Cl₂]Cl nH₂O ((1) L: norfloxacin (nf), n = 4; (2) L: ciprofloxacin (cp), n = 3; (3) L: enrofloxacin (enro), n = 5) were synthesized and characterized by chemical analysis UV–Vis and IR spectroscopy. In all complexes fluoroquinolone derivative acts as bidentate chelate ligand. The thermal behavior steps were investigated in synthetic air flow. The thermal transformations are complex processes according to TG and DTG curves including dehydration, quinolone derivative degradation, as well as RuCl₃ conversion in RuO₂.     

Variational principles for symmetric bilinear forms

Every compact symmetric bilinear form B on a complex Hilbert space produces, via an antilinear representing operator, a real spectrum consisting of a sequence decreasing to zero. We show that the most natural analog of Courant's minimax principle for B detects only the evenly indexed eigenvalues in this spectrum. We explain this phenomenon, analyze the extremal objects, and apply this general framework to the Friedrichs operator of a planar domain and to Toeplitz operators and their compressions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)