Intensity distribution in rotational line spectra

Completely resolved Doppler-free rotational line spectra of six vibronic two-photon bands in benzene C6 H6 and C6 D6 are presented. The excited final states possess different excess energies in S1 (1567 to 2727 cm−1 ) and are embedded in dense manifolds of background states with differing densities of states (1<rho<60 1/cm−1 ). The bands are analyzed by a statistical procedure. The intensity distribution of several hundreds of lines of each band is investigated. It is found that all weakly perturbed bands display a similar, peaked intensity distribution while in strongly perturbed bands the number of lines decreases monotonically with increasing intensity. The origin of this difference is discussed in terms of coupling to the many background states. The Journal of Chemical Physics is copyrighted by The American Institute of Physics

Some solutions of linearized 5-d gravity with brane

We consider linearized 5-d gravity in the Randall-Sundrum brane world. The class of static solutions for linearized Einstein equations is found. Also we obtaine wave solutions describing radiation from an imaginary point source located at the Planck distance from the brane. We analyze the fields asymptotic behavior and peculiarities of matter sources.Comment: Latex, 8 page

Dicke Coherent Narrowing in Two-Photon and Raman Spectroscopy of Thin Vapour Cells

The principle of coherent Dicke narrowing in a thin vapour cell, in which sub-Doppler spectral lineshapes are observed under a normal irradiation for a l/2 thickness, is generalized to two-photon spectroscopy. Only the sum of the two wave vectors must be normal to the cell, making the two-photon scheme highly versatile. A comparison is provided between the Dicke narrowing with copropagating fields, and the residual Doppler-broadening occurring with counterpropagating geometries. The experimental feasibility is discussed on the basis of a first observation of a two-photon resonance in a 300 nm-thick Cs cell. Extension to the Raman situation is finally considered

Non-linear spectroscopy of rubidium: An undergraduate experiment

In this paper, we describe two complementary non-linear spectroscopy methods which both allow to achieve Doppler-free spectra of atomic gases. First, saturated absorption spectroscopy is used to investigate the structure of the $5{\rm S}_{1/2}\to 5{\rm P}_{3/2}$ transition in rubidium. Using a slightly modified experimental setup, Doppler-free two-photon absorption spectroscopy is then performed on the $5{\rm S}_{1/2}\to 5{\rm D}_{5/2}$ transition in rubidium, leading to accurate measurements of the hyperfine structure of the $5{\rm D}_{5/2}$ energy level. In addition, electric dipole selection rules of the two-photon transition are investigated, first by modifying the polarization of the excitation laser, and then by measuring two-photon absorption spectra when a magnetic field is applied close to the rubidium vapor. All experiments are performed with the same grating-feedback laser diode, providing an opportunity to compare different high resolution spectroscopy methods using a single experimental setup. Such experiments may acquaint students with quantum mechanics selection rules, atomic spectra and Zeeman effect.Comment: 16 pages, 8 figure

Surface Hardening Low Alloy Structural Steel By Laser Welding

The paper studied the degree of surface hardening of various low-alloy structural steels by laser weld overlays. Laser welding carried out on the ”Scanner” and «Huffman HC-205.” Studies have been conducted microstructure and elemental composition of built-up layers and the heat-affected zones on steel substratesselected by scanning electron microscopy and X-ray microanalysis. There were also measured the microhardness and built according to the changes in the thickness microhardness themselves claddings and heat-affected zones. As a result, the optimal modes of application of the laser weld overlays on the substrate, allowing to minimize the size of the heat-affected zones and differences in microhardness values, whichreduces the likelihood of cracks and discontinuities. Keywords: surface hardening, nickel alloy, laser claddin

Lepidoptera (Insecta) of proposed specially protected natural area "Belokurikha nature park" (Northern Altai). First results

149 Lepidoptera species from 16 families were reported for the territory of the proposed protected area "Belokurikha Natural Park". This list is the primary data on the fauna of Lepidoptera in the region. Most of the species belongs to Euro-Siberian and Transpalaearctic groups

Brane Decay of a (4+n)-Dimensional Rotating Black Hole. II: spin-1 particles

The present works complements and expands a previous one, focused on the emission of scalar fields by a (4+n)-dimensional rotating black hole on the brane, by studying the emission of gauge fields on the brane from a similar black hole. A comprehensive analysis of the particle, energy and angular momentum emission rates is undertaken, for arbitrary angular momentum of the black hole and dimensionality of spacetime. Our analysis reveals the existence of a number of distinct features associated with the emission of spin-1 fields from a rotating black hole on the brane, such as the behaviour and magnitude of the different emission rates, the angular distribution of particles and energy, the relative enhancement compared to the scalar fields, and the magnitude of the superradiance effect. Apart from their theoretical interest, these features can comprise clear signatures of the emission of Hawking radiation from a brane-world black hole during its spin-down phase upon successful detection of this effect during an experiment.Comment: 35 pages, 19 figures, Latex fil

Comparative Evaluation of Protein Hydrolysates in the Process of Constructing Based on Them Nutrient Medium for Brucella Cultivating

Objective of the study is to conduct comparative assessment of specific activity of pancreatic hydrolysates of protein-containing products, both phytogenous and zoogenous, as regards Brucella test strains; and consequently, to develop nutrient medium for Brucella cultivation, to study its biological parameters. Materials and methods. Gelatin, soy, soy concentrate, corn gluten, fish meal, freshly frozen Caspian sprat, and bovine blood pancreatic hydrolysates, obtained using conventional methodology, served as the test objects. Determination of biological parameters of nutrient media, containing the studied hydrolysates was carried out using the test-strains of Brucella abortus 19 BA and B. melitensis Rev I. Results and discussion. Gelatin hydrolysate has the best biological parameters as regards the Brucella strains. Studied have been biological parameters of nutrient media, containing combination of gelatin hydrolysate and other selected hydrolysates. Experimental nutrient medium for Brucella cultivation has been developed. Comparative assessment of the experimental nutrient medium and two other commercial media used for cultivating Brucella has been performed

Brane decay of a (4+n)-dimensional rotating black hole: spin-0 particles

In this work, we study the `scalar channel' of the emission of Hawking radiation from a (4+n)-dimensional, rotating black hole on the brane. We numerically solve both the radial and angular part of the equation of motion for the scalar field, and determine the exact values of the absorption probability and of the spheroidal harmonics, respectively. With these, we calculate the particle, energy and angular momentum emission rates, as well as the angular variation in the flux and power spectra -- a distinctive feature of emission during the spin-down phase of the life of the produced black hole. Our analysis is free from any approximations, with our results being valid for arbitrarily large values of the energy of the emitted particle, angular momentum of the black hole and dimensionality of spacetime. We finally compute the total emissivities for the number of particles, energy and angular momentum and compare their relative behaviour for different values of the parameters of the theory.Comment: 24 pages, 13 figure

The correlation of experimental results for condensation of steam from its mixture with air in channel of plate heat exchanger based on mathematical modelling

The process of steam condensation in the presence of air in channels of plate heat exchanger is investigated experimentall and with mathematical modelling. The equation accounting for transvers mass flux on heat and mass transfer is obtained. The results allow design of platecondenserss for steam containing noncodensable gas