ESR study of Gd in TmSb: Determination of the host excited crystalline field splitting levels

The ESR thermal broadening of Gd in the metallic Van Vleck paramagnet, TmSb, is used to extract the excited crystalline field splitting energy level, Θ₅⁽²⁾, of Tm⁺³.     

Microbial sensors of ultraviolet radiation based on recA’::lux fusions

Escherichia coli strains containing plasmid-borne fusions of the recA promoter-operator region to the Vibrio fischeri lux genes were previously shown to increase their luminescence in the presence of DNA damage hazards, and thus to be useful for genotoxicant detection. The present study expands previous work by demonstrating and investigating the luminescent response of these strains to ultraviolet radiation. Several genetic variants of the basic recA'::lux design were examined, including a tolC modification of membrane efflux capacity, a chromosomal integration of the recA'::lux fusion, a different lux reporter (Photorhabdus luminescens instead of V. fischeri, allowing the assay to be run at 37 degrees C), and a different host bacterium (Salmonella typhimurium instead of E. coli). Generally, two modifications provided the fastest responses: the use of the S. typhimurium host or the P. luminescens lux reporter. Highest sensitivity, however, was demonstrated in an E. coli strain in which a single copy of the V. fischeri lux fusion was integrated into the bacterial chromosome.     

Volume‐dependent potential approach for tungsten

A scheme to produce density‐of‐states‐(DOS)‐dependent potentials for d‐metals on the basis of the local density approximation calculations is suggested. As an example this scheme is applied to construct a DOS‐dependent potential for tungsten. The second moment of the tungsten DOS is calculated. We show that the obtained potentials give a good agreement of cohesive properties with the experimental data. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 71: 343–348, 1999     

Influence of pH on the Spectral-Luminescent Characteristics of the Soft Protein Crown of Silver Nanoparticles

Journal of Applied Spectroscopy - The spectral and fluorescent characteristics of bovine serum albumin (BSA) molecules in the soft crown of silver nanoparticles (Ag-NPs) were studied at various pH...     

Twistorial examples of almost Hermitian manifolds with Hermitian Ricci tensor

We construct new twistorial examples of non-Kähler almost Hermitian manifolds with Hermitian Ricci tensor by means of a natural almost Hermitian structures on the twistor space of an almost Hermitian four manifold.     

Harmonic almost-complex structures on twistor spaces

We prove that the Atiyah-Hitchin-Singer [1] and Eells-Salamon [6] almost-complex structures on the negative twistor space of an oriented Riemannian four-manifold are harmonic in the sense of C. Wood [17, 18] if and only if the base manifold is, respectively, self-dual or self-dual and of constant scalar curvature. The stability of these almost-complex structures is also discussed. Research supported in part by the NSF grant INT-9903302. Both authors are members of EDGE, Research Training Network HPRN-CT-2000-00101, supported by the European Human Potential Programme.     

Normality of the Twistor Space of a 5-Manifold with an Irreducible SO(3)-Structure

Mediterranean Journal of Mathematics - A manifold with an irreducible SO(3)-structure is a 5-manifold M whose structure group can be reduced to the group SO(3), non-standardly imbedded in SO(5)....     

Study of the local symmetry properties of Dy in the metallic compound,LaSb

Electron Spin Resonance study of Dy in LaSb single crystal indicates appreciable angular variation of the ESR linewidth at X band frequency. The data is interpreted in terms of a random stress model with possible local tetragonal distortions.     

The configuration of the hydrogen atoms in HfV2Hx compounds at low temperatures: A NMR study

The ⁵¹V nuclear electric quadrupole interaction and the shape of the proton resonance line in the low temperature phase of the HfV₂H_x (0≤x≤4) compounds has been studied by NMR. The data yield information about the hydrogen arrangement in the low temperature phase. They confirm the results of recent neutron diffraction studies that for x=4 and ordered super lattice of the hydrogen atoms exists, with the hydrogen atoms occupying only tetrahedral interstitial sites formed by two Hf and two V atoms. Our results show that in the lower concentration compound the hydrogen atoms most probably also occupy the same type of interstices, but without crystallographic order.