Nitration Mechanism of Dibenzo-18-crown-6 with Potassium Nitrate in Polyphosphoric Acid Alkylation with Substituted Phenacyl

Russian Journal of Organic Chemistry -     

The CCFM Monte Carlo generator CASCADE Version 2.2.03

The European Physical Journal C - Cascade is a full hadron level Monte Carlo event generator for ep, γp and $p\bar{p}$ and pp processes, which uses the CCFM evolution equation for the initial...     

Sulfonation of Benzocrown Ethers by Potassium Sulfate in Polyphosphoric Acid

A new method is developed for the sulfonation of benzocrown ethers with potassium sulfate in polyphosphoric acid. The reaction takes place spontaneously and gives high yields of the sulfonic acids.     

Rapid determination of copper(I,II) ions using reagent indicator paper

A rapid, sensitive, and highly selective test based on the reaction of copper(I) with thio-Michler’s ketone was developed for the detection and semiquantitative determination of 0.001–2 mg/L copper in natural and potable waters using preconcentration in a portable indicator device. Diffuse reflectance spectroscopy was used to select reagent concentrations for immobilization on paper and study the conditions and performance characteristics of the procedure.     

Electronic and spatial structure of nanoclusters of Sn2P2S6 ferroelectric crystals

The results obtained from ab initio calculations of the optimized configuration and electronic structure of the cluster models of Sn₂P₂S₆ ferroelectric crystals are presented. The calculations have been performed using the spin-restricted Hartree-Fock method and the density functional theory in the DZVP basis set. It has been shown that the clusters are stable and retain the topology of the simulated crystal. The influence of the cluster sizes on the properties under investigation has been analyzed.     

Search for the ϕ → π+π−γγ and ϕ → π+π−η decays with the CMD-2 detector

The ? → π⁺π^?γγ and ? → π⁺π^?η decays are sought in the experimental data obtained with the CMD-2 detector in the region of the ?-meson resonance. Upper limits ?(? → ππγγ)< 1.2 × 10^?4 and ?(? → ππη) < 6.1 × 10^?5 (both at a C.L. of 90%) are determined for the branching ratios of these decays.     

Intercalation of Iron Atoms under Graphene Formed on Silicon Carbide

The intercalation of iron under a graphene monolayer grown on 4H-SiC(0001) is studied. The experiments have been carried out in situ under conditions of ultrahigh vacuum by low-energy electron diffraction, high-energy-resolution photoelectron spectroscopy using synchrotron radiation, and near carbon K-edge X-ray absorption spectroscopy. The deposited iron film thicknesses have been varied within 0.1–2 nm and the sample temperatures from room temperature to 700°C. It is shown that the intercalation process begins at temperatures higher than ~350°C. In this case, it is found that intercalated iron atoms are localized not only between graphene and a buffer layer coating SiC, but also under the buffer layer itself. The optimal conditions of the intercalation are realized in the range 400–500°C, because, at higher temperatures, the system becomes unstable due to the chemical interaction of the intercalated iron with silicon carbide. The inertness of the intercalated films to action of oxygen is demonstrated.

     

The OLVE-HERO Calorimeter Prototype Tests at Heavy Ion Beams of CERN SPS

Physics of Particles and Nuclei Letters - A project of the OLVE-HERO space detector is proposed for CR measurement in the range of 1012–1016 eV and will include a large ionization-neutron 3D...