On the transverse momentum distribution of strange hadrons produced in relativistic heavy ion collisions

Particles with strange quark content produced in the system 1.93A·GeV⁵⁸Ni on⁵⁸Ni have been investigated at GSI Darmstadt with the FOPI detector system. The correlation of these produced particles was analyzed with respect to the reaction plane. baryons exhibit a very pronounced sideward flow pattern which is qualitatively similar to the proton flow. However, the kaon (K ⁺,K _s ⁰ ) flow patterns are significantly different from that of the protons, and their form may be useful to restrict theoretical models on the form of the kaon potential in the nuclear medium.The authors would like to thank G. Q. Li for helpful correspondence.     

Semiconductor-encapsulated peptide-amphiphile nanofibers

We report here on the use of peptide-amphiphile (PA) nanofibers displaying the S(P)RGD peptide sequence on their exterior as templates for the mineralization of cadmium sulfide (CdS). At low Cd:PA ratios, the nanofibers nucleate and organize quantum-confined 3-5 nm CdS nanocrystals into linear arrays. Tubular structures, in which the PA fibers are completely encapsulated by the semiconductor, are produced at higher Cd:PA ratios.     

Novel podands and macrocycles with diacetal (tetraoxadecalin) cores: synthesis, structure, stereochemistry and cation inclusion

A series of functionalized 2,6-dialkyl-cis-1,3,5,7-tetraoxadecalin podands (3-10, alkyl = hydroxy-, mesyloxy-, halo-, azido- and aminomethyl and -ethyl) were prepared, characterized, and used as precursors for a new and interesting class of macrocycles and cryptands (12-21), with the aim to use these as host-guest inclusion systems. Extensive spectroscopic work was performed, structural endorsement was obtained from X-ray diffraction analyses and further insight into the structures was obtained from theoretical/computational studies. A number of macrocycles in the series exhibited good complexation with alkaline-earth metal ions.     

Separation of the First Adsorbed Layer from Others and Calculation of the BET Compatible Surface Area from Type II Isotherms

In the previous paper it has been proven that a BET compatible specific surface area, asc(N2, 77), can be calculated from any Type I isotherm measured below the critical temperature. In this paper it is proven that the same calculation can be performed from any Type II isotherms if the isotherm has a pure monolayer domain. In order to distinguish the mono- and multilayer adsorption the relative free energy of the surface as a function of the adsorbed amount, pir(ns), and the functions psi(pr) and psi(ns) are applied, both defined by the differential expression (ns/pr)(dpr/dns). When the multilayer adsorption becomes the dominant process then the function pir(ns) has a point of inflexion and functions psi(pr) and psi(ns) have maximum values. It has been demonstrated that in most of the Type II isotherms the mono- and multilayer domains can be separated, so the monolayer component isotherm can be calculated by the T (Tóth) equation. Therefore, it is possible to calculate the BET compatible specific surface area discussed in detail in the previous paper. It has also been proven that there are Type II isotherms which describe only multilayer adsorption; i.e., the functions psi(pr) and psi(ns) do not have maximum values. In these cases the Harkins-Jura equation should be applied. Copyright 1999 Academic Press.