General Spectral Properties Research Articles

Environment dependence of spectral and dissipative properties of an open spin system.

In this paper we give a self-contained account of some general spectral and dissipative properties of open spin systems. These properties are discussed in the framework of completely positive quantum dynamical semigroup equations. Special classes of such open systems are studied in detail. The effects of the environment symmetry and the spin-surrounding interaction multipolarities on the shiftings and the splittings of energy levels and relaxation parameters are explained. The physical meaning of relaxation parameters is found. \textcopyright{} 1996 The American Physical Society.

Etude spectrale d'une famille d'op�rateurs non-sym�triques intervenant dans la th�orie des champs de reggeons

In this paper, we study a few spectral properties of a non-symmetrical operator arising in the Gribov theory. The first and second section are devoted to Bargmann's representation and the study of general spectral properties of the operator: For λ'>0 and λ'2^μλ' + λ2. We prove that the solutions of the equation u'(t) + Hλ>}μfλu(ί) = 0 are expandable in series of the eigenvectors of Hλ>tlXtλ for ί>θ/' ' In the last section, we show that the smallest eigenvalue σ(α) of the operator Hλ\μ,λ,a is analytic in α, and thus admits an expansion: σ(α) = σo + ασ1 + α2σ2+ . . ., where σ0 is the smallest eigenvalue of the operator Hλ'ίfltλ>0.

Spectrophotometric Investigation of Iron(III)-N-Phenylcin-namohydroxamic Acid System

Abstract N-Phenylcinnamohydroxamic acid, PCHA, was found to react with iron (III) to form complex species of different colour depending upon the reaction environment. The reaction conditions for the formation of the complex species were studied in aqueous-ethanolic medium. The general spectral properties of the species were investigated. The absorption curves were found to have two isobestic points. The number and composition of the complexes were determined and found to have composition 1:1, 1:2, 1:3 (Fe: PCHA). The wavelengths of the maximum absorbances were figured out to be 535, 495, and 445 nm for the I, II, and III complex species, respectively. It was verified that the Beer's law holds for these complexes at all wavelengths, and for the mixtures at the wavelengths of the isobestic points in a wide range of pH. The stepwise stability constants have been determined by the method of isobestic point and found to be log K1 = 11.55, log K2 = 10.11, and log Kg3 = 7.44 for the I, II, and III complex specie...

Inhibition of 25-hydroxyvitamin D 1α-hydroxylase by renal mitochondrial protein kinase-catalyzed phosphorylation

Partially purified chick kidney mitochondrial Type II protein kinase catalyzes the phosphorylation of 1α-hydroxylase cytochrome P-450 without affecting the rate of product formation in vitro when 1α-hydroxylase activity is reconstituted by the addition of [ferredoxin] and [ferredoxin reductase] to the phosphorylated cytochrome. The cytochrome's effective concentration, or its general spectral properties did not change upon phosphorylation. However, when the cytochrome and its ferredoxin were present simultaneously during the phosphorylation reaction, reconstitution of 1α-hydroxylase activity by the addition of ferredoxin reductase failed to catalyze product formation. Although a several fold increase in the kinase activity could be demonstrated in the presence of cAMP, the above phosphorylation effects appear to be cAMP-independent.

Spectrophotometry of IO: Preliminary Voyager 1 results

Multispectral images of Io acquired with the Voyager 1 narrow‐angle camera agree with Earth‐based spectrophotometry to better than 10%. Although the surface materials have general spectral properties similar to various allotropes of sulfur, their ultraviolet (UV) reflectances are much higher. It is likely that varying amounts of SO2 frost mixed with or absorbed on sulfur‐rich materials raises the UV reflectance. The possible association with large amounts of SO2 with low temperature forms of sulfur in the white patches on Io is consistent with Io surface models in which SO2 and S exist in thermally stable stratified zones.

High-resolution X-ray spectra of solar flares. IV - General spectral properties of M type flares

view Abstract Citations (119) References (11) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS High-resolution X-ray spectra of solar flares. IV - General spectral properties of M type flares Feldman, U. ; Doschek, G. A. ; Kreplin, R. W. ; Mariska, J. T. Abstract The spectral characteristics in selected narrow regions of the X-ray spectrum of class M solar flares are analyzed. High-resolution spectra in the ranges 1.82-1.97, 2.98-3.07, 3.14-3.24 and 8.26-8.53 A, which contain lines important for the determination of electron temperature and departure from ionization equilibrium, were recorded by spaceborne Bragg crystal spectrometers. Temperatures of up to 20,000,000 K are obtained from line ratios during flare rise phases in M as well as X flares, while in the decay phase the calcium temperature can be as low as 8,000,000 K, which is significantly lower than in X flares. Large nonthermal motions (on the order of 130 km/sec at most) are also observed in M as well as X flares, which are largest during the soft X-ray rise phase. Finally, it is shown that the method proposed by Gabriel and Phillips (1979) for detecting departures of electrons from Maxwellian velocity distributions is not sufficiently sensitive to give reliable results for the present data. Publication: The Astrophysical Journal Pub Date: November 1980 DOI: 10.1086/158434 Bibcode: 1980ApJ...241.1175F Keywords: Solar Flares; Solar Spectra; Solar X-Rays; X Ray Spectra; Electron Energy; High Resolution; Spectral Line Width; Solar Physics full text sources ADS | Related Materials (8) Part 1: 1979ApJ...233L.157D Part 2: 1980ApJ...238..365F Part 3: 1980ApJ...239..725D Part 5: 1981ApJ...245..315D Part 6: 1982ApJ...260..885F Part 7: 1985ApJ...292..309K Part 8: 1986ApJ...306..327K Part 9: 1989ApJ...345.1079D

Carbenium Periodide, I / Carbenium Periodides, I

Abstract Carbocations of the tri-phenylmethylseries give with In - salts which are characterized by the natur of the anion. The preparation and general physical, spectral and chemical properties of tris-(4-dimethylaminophenyl)-carbenium-triiodid (1), a salt of crystal violet, and bis-(4-dimethylaminophenyl)-phenyl-carbenium-triiodid (2), a salt of malachite green, are described. The structure of the cations and anions of these carbeniumsalts is determined from their spectral data.

Isolation of ascaris haemoglobins

1.1. The two haemoglobins of Ascaris have been studied in an effort to purify them, and to determine their approximate molecular weights and general spectral properties.2.2. It has not been found possible to obtain either haemoglobin free from contaminating protein except during ultracentrifugation.3.3. The isoelectric points of the haemoglobins are about 5.0 and 6.7.4.4. The molecular weights are about 14 000 and 280 000. These are uncommon values for haemoglobins and are apparently the first reported for nematode worms.5.5. The general spectral characters of both haemoglobins conform to those of other haemoglobins. However, even allowing for contamination, the protein absorption seems to be unusually high. It has not been possible to determine the reason for this.6.6. The properties of both haemoglobins differ from those of mammalian haemoglobin in every respect examined, and they are therefore specific proteins produced by the worm itself.