A non-destructive analysis of the influence of sputter-etching on the magnetic surface properties of manganese zinc ferrite (100) surfaces using ellipsometry and the polar magneto-optical Kerr effect

Ellipsometry and the polar magneto-optical Kerr effect have been used in the photon energy range 0.65 eV?hv?5.4 eV to study sputter-etched manganese zinc ferrite (100) surfaces. With an annealed sample as a reference, a stratified media calculation indicates the presence of a paramagnetic surface layer of 8–40 nm thickness, depending on sputter parameters. Conversion electron Mössbauer spectroscopy and Rutherford backscattering spectroscopy fully confirmed these results.     

A short synthetic route to biologically active (+/-)-daurichromenic acid as highly potent anti-HIV agent

The efficient total synthesis of biologically interesting (+/-)-daurichromenic acid is accomplished starting from 2,4-dihydroxy-6-methylbenzoic acid or 2,4-dihydroxy-6-methylbenzaldehyde in one or two steps.     

Measurement of the refractive index and optical absorption spectra of epitaxial bismuth substituted yttrium iron garnet films at uv to near-ir wavelengths

Refractive-index and optical-absorption spectra of Bi-substituted yttrium iron garnet films, epitaxially grown by liquid-phase epitaxy, have been measured in the spectral regime 0.26 m1.9 m by thin-film interference for 0.52 m and by ellipsometry for0.52 m. The Y_3–x–y Bi _x Pb _y Fe_5–z Pt _z O₁₂ films contain bismuth in the range Ox 1.42, lead in the range 0.01 y0.08 and platinum in the range 0.005<=z0.03. There is satisfactory coincidence between the results from ellipsometry and thin-film interference in the overlapping wavelength region. The materials investigated are the same as reported earlier from this laboratory in ter mof their magnetic and magnetooptic properties.     

Synthesis and molecular and electronic structure of dibenz(b,f)-1,4-oxazepine

Russian National Scientific-Research Institute of Organic Chemistry and Technology. Translated fromZhurnal Struktumoi Khimii, Vol. 36, No. 1, pp. 197–201, January–February, 1995.     

Synthesis of 7-Hydroxyspiropyran

The 7-acetoxyspiropyrans (4a and 4b) have been prepared by the reaction of Fischer's bases (3) with 2,4-diacetoxybenzaldehyde in refluxing ethanol in moderate yields. The acetyl group of 7-acetoxy-spiropyran 4a was easily removed to give a 7-hydroxyspiropyran 6 in high yield under the basic condition.     

Synthesis of 1,3-Diketones by Reaction of α-Haloketones with Acyl Cyanides Promoted by Samarium Diiodide

α-Haloketones reacted with acyl cyanides to form 1,3-diketones in the presence of samarium diiodide. The reaction was assumed to proceed via a mechanism involving samarium enolates formed in situ from α-haloketones.     

Picosecond Soliton Pulse Generation with a Zinc Phthalocyanine Thin-Film Saturable Absorber Via Mode Locking in an Erbium-Doped Fiber Laser Cavity

Journal of Russian Laser Research - In this paper, we employ a Zinc Phthalocyanine (ZnPc) organic material to construct a saturable absorber (SA) that is used in a laser cavity to generate...     

Multi-criteria risk evaluation model for developing ventilator-associated pneumonia

Central European Journal of Operations Research - Ventilator-associated pneumonia is a hospital-acquired infection of the lungs occurring in mechanically ventilated patients. An active risk...