X-ray spectra of multiply-charged hollow ions in the emission from a femtosecond laser plasma

A new type of quasicontinuous emission spectrum from a femtosecond laser plasma near the Ly_α line of H-like ions is obtained and interpreted. It is shown that these spectra are emitted by multiply charged hollow ions, which are present in the plasma on account of its ultrahigh density, which, in turn, is due to the use of high-contrast laser pulses for producing the plasma. A new spectroscopic approach based on analysis of the composition of spectral complexes of hollow ions is discussed. Pis’ma Zh. éksp. Teor. Fiz. 67, No. 7, 467–472 (10 April 1998)     

Externally applied electric fields on immiscible lipid monolayers: repulsion between condensed domains precludes domain migration

Lipid and protein molecules anisotropically oriented at a hydrocarbon-aqueous interface configure a dynamic array of self-organized molecular dipoles. Electrostatic fields applied to lipid monolayers have been shown to induce in-plane migration of domains or phase separation in a homogeneous system. In this work, we have investigated the effect of externally applied electrostatic fields on different lipid monolayers exhibiting surface immiscibility. In the monolayers studied, lipids in the condensed state segregate in discontinuous round-shaped domains, with the lipid in the liquid-expanded state forming the continuous phase. The use of fluorescent probes with selective phase partitioning allows analyzing by epifluorescence microscopy the migrations of the domains under the influence of inhomogeneous electric fields applied to the surface. Our observations indicate that a positive potential applied to an electrode placed over the monolayer promotes a repulsion of the domains until a steady state is reached, indicating the presence of a force opposed to the externally applied electric force. The experimental results were modeled by considering that the opposing force is generated by the dipole-dipole repulsion between the domains.     

Spatiotemporal synchronization of coupled oscillators in a laboratory plasma

The spatiotemporal synchronization between two plasma instabilities of autonomous glow discharge tubes is observed experimentally. For this purpose, two tubes are placed separately and two chaotic waves interact with each other through a coupler. When the coupling strength is changed, the coupled oscillators exhibit synchronization in time and space. This is the first experimental evidence of spatiotemporal synchronization by mutual chaotic wave interaction in plasma.     

Zur Chemie in Schmelzlösungen. IV. Darstellung von kristallinen Boraten M2+M4+(BO3)2

Borates of the compositions formulated above are prepared in crystalline form by cooling their molten solutions in the corresponding borate M²⁺O · xB₂O₃. Some properties of the compounds are reported.