Propriétés Régularisantes de Certains Semi-Groupes Non Linéaires

Let φ be a convex l.s.c. function fromH (Hilbert) into ] - ∞, ∞ ] andD(φ)={u ∈H; φ(u)<+∞}. It is proved that for everyu ₀ ∈D(φ) the equation − (du/dt)(t ∈ ∂φ(u(t)),u(0)=u ₀ has a solution satisfying ÷(du(t)/dt)÷ ≦(c ₁/t)+c ₂. The behavior ofu(t) in the neighborhood oft=0 andt=+∞ as well as the inhomogeneous equation (du(t)/dt)+∂φ(u(t)) ∈f(t) are then studied. Solutions of some nonlinear boundary value problems are given as applications.      

Thapsigargin,constitution of a sesquiterpene lactone histamine liberator from thapsia garganica

The major skin irritating constituent of the root of Thapsia garganica L. has been shown to be a hexaoxygenated-C₆-guaianolide esterificated with four carboxylic acids.     

Synthesis and structure of the new mesoionic 1-thiasydnonimine system

Synthesis of 5-acylimino-3-methyl-1,2,3-thiadiazole 4 is described and its molecular structure is confirmed by NMR and X-Ray diffraction analysis.     

Time resolved study of superelastic collisions in laser excited strontium vapor

We present a time-resolved experimental study of ionization by superelastic collisions in excited strontium vapor. Using short duration laser pulses for resonant excitation, we clearly observe that a delay time is necessary to reach runaway collisional ionization after the end of laser excitation.     

Zur Photoleitung von Sb2Se3-Aufdampfschichten

Ohne Zusammenfassung     

Rosigenin,an unusual metabolite from mycosphaerella rosigena1

A new metabolite, 3,6-dimethyl-4,10-dihydroxy-2-oxaspiro[4.5]dec-7-en-1,9-dione (1a), was isolated from a strain of Mycosphaerella rosigena grown on potato-agar medium. The structure was determined on the basis of chemical and spectroscopic evidence and confirmed by X-ray analysis.     

Messung der Neutronenpolarisation bei der Reaktion12C(d,n 0)13N mit Hilfe der Mott-Schwinger-Streuung

The polarization of neutrons produced in the reaction¹²C(d, n ⁰)¹³N was measured. Deuterons from the Karlsruhe isochronous cyclotron were used to induce this reaction at 51,5 MeV laboratory energy. The degree of polarization was determined by using the special features of Mott-Schwinger scattering. With an uranium scatterer analysing efficiencies of up to 0.92 can be obtained at very small angles (0.23°). The analysing efficiency can be calculated if the differential cross section at 0° and the total cross section is known. These quantities were experimentally determined. The differential cross section for 49.4 MeV neutrons, scattered by uranium, was measured between 0.88° and 2.10°. By an extrapolation the value 43.4±2.6 b/sr was found for the nuclear differential cross section at zero degree. A total cross section ofσ _t=4.80±0.22 b was obtained. The neutron polarization was measured at a reaction angle of 24.5° and the result isP=?0.45±0.07. This value is fairly above the semiclassical 1/3 limit and can be only explained, if spin orbit forces are taken into account. For (d, n) reactions this is the first neutron-polarization measurement above an energy of 20 MeV.     

Wide-angle high-energy proton spectra by 800 MeV/A C,Ne, and Ar beams

Inclusive proton spectra, as well as two-particle correlations, resulting from collisions between energetic nuclei have been measured. Protons associated with large momentum transfers show exponential-type energy distributions having a decay constant about (70–90 MeV)^?1. For light-mass targets a strong two-particle correlation has been observed, which is kinematically consistent with quasi-elastic pp scatterings.     

The tensor polarization of 5Li (32−) in the reaction α + d → α + p + n

At the Hamburger Isochronous Cyclotron the formation of the particle unstable ground state of ${}^5\text{Li(}\text{3}\text{2}{}^{\mathrm{?}}$ has been investigated in the reaction α + d → α + p + n at E_α = 28.3 MeV. The neutrons were detected in two liquid scintillation counters, while a large Si (Li) detector was used to observe the α-particles. In a first analysis, the tensor polarization parameters of the five-nucleon system ⁵Li are determined from the experimental data. The results are in quite good agreement with theoretical predictions of Hackenbroich et al.