Single-particle levels and spin-orbit splitting in the vicinity of the doubly magic nucleus <Superscript>48</Superscript>Ca

On the basis of a detailed analysis of available experimental data, the spectrum of single-particle states and the isotopic dependence of spin-orbit splitting are determined for nuclei in the vicinity of the doubly magic nuclide ⁴⁸Ca. The spectrum of excited states of the isobaric nucleus ⁴⁸Sc is calculated.     

Anomalies in the Absorption and Reflection of a High-Power Ultrashort Laser Pulse by a Plasma with a Solid-State Density

The patterns of absorption and reflection of an ultrashort laser pulse by a plasma with a solid-state density, which are realized in the mode of the normal skin effect, are studied. It is shown that a decrease in low-power pulse duration shorter than the period corresponding to the fundamental frequency of radiation leads to an increase in the absorption coefficient. If the pulse power is so high as to provide electron heating during a time shorter than the reciprocal fundamental frequency, nonlinear suppression of absorption takes place and the spectrum of the reflected radiation contains odd harmonics of the fundamental frequency.     

Study of ferroelectric switching by domain-wall induced light scattering

Measurements of 90°-scattering of weak laser light are used to investigate pulsed domain switching in ferroelectrics. The studies were performed on strontium-barium niobate (SBN) single crystals. A good agreement of the switching parameters estimated from the optical measurements with those obtained by means of conventional electrical methods proves the validity of the optical method for switching studies. Due to the limited scattering volume in all three spatial dimensions, the method facilitates local probing of the switching within the crystal bulk. In particular, local specialities of the domain density can be detected. Furthermore, the excellent time resolution inherent in optical probing techniques allows for a comprehensive study of the dynamics.     

Dimeric stilbenes of the wood of Maackia amurensis

Dimeric stilbenes have been isolated from the wood of Amur maackia for the first time. Two of them have been identified as the known scirpusins A and B. The structure of a new dimeric stilbene with a dioxane linkage, which has been called maackinin, has been established. The PMR and¹³C NMR spectra of the substances isolated have been studied in detail.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 468–476, September–October, 1992.     

A structural investigation of a D-glucan fromYersinia pseudotuberculosis of serotype VI

It has been established that an -D-glucan isolated fromYersinia pseudotuberculosis, serotype VI, is branched and contains -14- and -16-bound D-glucopy-ranose residues in the main chain and the side chains, respectively.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostock. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 151–154, March–April, 1981.     

Steroid compounds of marine sponges. XI. Steroids of the Australian spongeTrachyopsis sp.

The compositions of two steroid fractions from the Australian spongeTrachvopsis sp. have been investigated. The fractions of steroid sulfates consisted of the trisulfates of halistanol (76%) and of 24-isopropyl-5-cholest-22-ene-2,3,6-triol (20%). In the sterol fraction, axinyssasterol (64%) and 24-isopropyl-5-cholest-22Z-en-3-ol (30%) were identified.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedineni, No. 2, pp. 215–218, March–April, 1990.