Distribution of Ir and Pt isotopes produced as fragments of 1 A GeV Au projectiles: a thermometer for peripheral nuclear collisions

Cross sections of iridium and platinum isotopes have been measured, which were produced as fragments from ¹⁹⁷Au projectiles interacting with aluminum target nuclei at 1 A GeV. The fragments were identified by a kinematic analysis (ΔE−Bρ-time-of-flight) and by an ion-optical separation at the projectile-fragment separator FRS at GSI. Indications are found for high excitation energies and weak proton-neutron correlations in the peripheral nuclear-collision process.     

Experimental evidence for the influence of the atomic shell structure on the energy loss of high energy heavy ions in matter

Secondary electron yield measurements for ²⁵²Cf fission products in carbon foils reveal significant deviations for the electronic stopping cross section from semiempirical predictions. This effect may correspond to the Z₁ oscillations observed previously at much lower ion velocities.     

Unelastische Elektronenstreuung an14N für Anregungsenergien zwischen 8,5 und 11,5 MeV

¹⁴N was investigated by inelastic scattering of 35... 58 MeV electrons (scattering angles 117 to 165°). For theM1-transitions to the 2⁺,T=1 levels at 9.17 and 10.43 MeV, ground state radiation widths of (7.7±0.9) eV, and (12.1±1.5) eV, respectively, were obtained. The ratio of these two widths is 1.57±0.07. The 3^?,T=1 level at 8.90 MeV is excited by anM2-transition withΓ _γ ⁰ =(6.6±2.2) · 10^?3 eV. An excitation of a level at (11.01±0.07) MeV is observed.     

Evidence for an isomeric state in 216Th

A new α-line with E_α = 9.912±0.020 MeV is assigned to an isomeric state in ²¹⁶Th. It decays with a half-life of $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 180±40 μ}\text{s}$. There are indications for a dominating γ-branch.     

The electrical conductivity of binary disordered systems,percolation clusters,fractals and related models

We review theoretical and experimental studies of the AC dielectric response of inhomogeneous materials, modelled as bond percolation networks, with a binary (conductor-dielectric) distribution of bond conductances. We first summarize the key results of percolation theory, concerning mostly geometrical and static (DC) transport properties, with emphasis on the scaling properties of the critical region around the percolation threshold. The frequency-dependent (AC) response of a general binary model is then studied by means of various approaches, including the effective-medium approximation, a scaling theory of the critical region, numerical computations using the transfer-matrix algorithm, and several exactly solvable deterministic fractal models. Transient regimes, related to singularities in the complex-frequency plane, are also investigated. Theoretical predictions are made more explicit in two specific cases, namely R-C and RL-C networks, and compared with a broad variety of experimental results, concerning, for example, granular composites, thin films, powders, microemulsions, cermets, porous ceramics and the viscoelastic properties of gels.     

Treatment of SMC Composite Waste for Recycling as Reinforcing Fillers in Thermoplastics

Needs for recycling thermoset composite materials are considerably increasing. Unfortunately, such materials are particularly difficult to recycle due to their crosslinked nature. In this paper, we focus on the case of Sheet Moulding Compounds (SMC), which consist of an unsaturated polyester filled with glass fibres and calcium carbonate. We consider the possibilities of mechanical treatments allowing to obtain ground fractions that could be used as fillers for the reinforcement of thermoplastics. Two processes are described and compared with an existing industrial one. Finally, optimised fractions of SMC waste are introduced into polypropylene, leading to promising results in term of mechanical properties.     

A generalized hecke identity

The classical Hecke identity gives the Fourier transform of the product of a homogeneous harmonic polynomial h times the Gaussian e^−1/2<...>. A similar formula is valid when the Gaussian is replaced by the tempered distribution e^i/2<...>. It is shown that there is a similar identity when the inner product is replaced by an indefinite quadratic formq and h is a Л-harmonic distribution, where Л is the differential operator canonically associated toq. Another generalization is obtained in the context of representations of Jordan algebras, in the spirit of Herz's previous work on matrix spaces.