The measurement of the absorption spectra of chlorine e 6 photosensitizer and hemoglobin in whole blood by multiple light scattering

The potential of using multiple light scattering methods to monitor the state and concentration of photosensitizer and hemoglobin in whole blood is demonstrated. Samples of whole blood with various contents of chlorine e ₆ photosensitizer were studied in the spectral region of 620–850 nm. On the basis of experimentally measured coefficients of diffuse reflection and transmission, absorption spectra of blood with and without the photosensitizer and the concentrations of oxy-, deoxy-, and methemoglobin in the samples are calculated. On the basis of this information, the absorption spectrum of chlorine e ₆ in whole blood is reconstructed and its state and concentration are estimated for the first time. It is found that chlorine e ₆ in whole blood occurs mainly in the monomer form.     

Temporal characteristics of emission of working mixtures of a HgBr/HgCl excimer lamp

Results of a study of temporal characteristics of the emission of gas-discharge plasma of atmospheric pressure in multicomponent mixtures (mercury dibromide and dichloride with helium and additions of molecular nitrogen and xenon) of working media of HgBr/HgCl excimer lamps are presented. Gas-discharge plasma was produced and components of the working mixture were excited by high-frequency barrier and surface discharges occurring simultaneously. The repetition rate of the pumping pulse and its duration are 1000 Hz and ～100 ns, respectively. It is found that the amplitude and the length of emission pulses and their trailing edge are modified in HgBr₂: HgCl₂: Xe: He and HgBr₂: HgCl₂: N₂: He mixtures when xenon and molecular nitrogen are added, as compared to a HgBr₂: HgCl₂: He mixture. Regularities observed in temporal characteristics of gas-discharge plasma emission are discussed.     

Optimization of parameters and the ultimate sensitivity of interferometric detectors of gravitational waves

The signal-to-shot-noise ratio is calculated for three types of laser interferometers used in gravitational wave detectors: for two types of Fabry-Perot interferometers (with direct reading of the output signal and with the modulation technique used for outcoupling the signal) and for the Michelson interferometer with Fabry-Perot arms. It is shown that the signal-to-noise ratio can be substantially increased by using “supermirrors” with losses of the order of 10 ^?6. It is very important, in this case, to properly choose the mirror transmittance, because, otherwise, the sensitivity inevitably decreases by orders of magnitude and the requirements of lasers become more stringent. The efforts to increase the signal-to-noise ratio by increasing the power are limited either by an insufficient laser power or by the overheating of interferometer mirrors. Our estimates show that the present-day technical level with laser power of about 1 W provides sufficient sensitivity for detecting gravitational waves.     

Transcendence degree of zero-cycles and the structure of Chow motives

In the paper we introduce a transcendence degree of a zero-cycle on a smooth projective variety X and relate it to the structure of the motive of X. In particular, we show that in order to prove Bloch’s conjecture for a smooth projective complex surface X of general type with p _g = 0 it suffices to prove that one single point of a transcendence degree 2 in X(ℂ), over the minimal subfield of definition k ⊂ ℂ of X, is rationally equivalent to another single point of a transcendence degree zero over k. This can be of particular interest in the context of Bloch’s conjecture for those surfaces which admit a concrete presentation, such as Mumford’s fake surface, see [Mumford D., An algebraic surface with K ample, (K ²) = 9, p _g = q = 0, Amer. J. Math., 1979, 101(1), 233–244].     

On dense free subgroups of the automorphism group

We obtain results on existence of dense free subgroups of the automorphism group of a homogeneous model.     

Symmetry of crystals composed of two Bravais sublattices in 6D crystal spaces

It is shown that the symmetry of crystals composed of two Bravais sublattices can be determined in 6D spaces, which are two orthogonal 3D subspaces. Twenty one sets in 6D space satisfy this requirement. The Bravais classes in these sets and the conditions of translation compatibility of orthogonal 3D subspaces are discussed. A consideration of the subordination scheme for systems leaves only 19 significant sets. Crystals with a fluorite lattice, in which the cation sublattice has the translational symmetry of the crystal, and crystals with a cuprite lattice, in which the anion and cation sublattices have different translational symmetries, are considered as an illustration.     

X-ray diffraction study of 1,5-bis(2-Formylphenoxy)pentane

1,5-Bis(2-Formylphenoxy)pentane was studied by X-ray diffraction. There are two crystallographically independent molecules with similar geometric parameters in the asymmetric unit of the crystal structure. The molecules occupy special positions on a rotation axis.