Gas‐Kinetic Temperature of Planar High‐Frequency Capacitive Discharge Plasma in N2/CO2/He Gas Mixtures

Using methods of emission spectroscopy, we have determined the gaskinetic temperature fields of planar highfrequency capacitive discharge plasma in N₂/CO₂/He gas mixtures depending on the excitation frequency, discharge current, pressure, and chemical composition of the mixture. It is shown that the dominant contribution to the neutral component heating in the center of the discharge chamber is made by the processes of V–T relaxation of vibrationally excited molecules N₂(X ¹, V) and CO₂(X ¹, V), whereas in the zones near the electrodes an important role in the heating is played, along with the V–T relaxation of the N₂(X ¹, V) and CO₂(X ¹, V) molecules, by the processes of deactivation of the metastable states A ³ of the N₂ molecule.     

Photometric and fluorimetric study of the acid-base behavior of 2,2′-diquinolyl and 2,2′,2″-terpyridyl

A photometric and fluorimetric study of the acid-base behavior of 2,2-diquinolyl and 2,2,2-terpyridyl was performed. In sulfuric acid medium, the doubly charged 2,2-diquinolynium ion undergoes the first dissociation atH ₀=0.20±0.09, as determined by fluorimetry (_ex=336 nm, _em=424 nm). Photometric titration is less accurate because of the overlapping of the absorption spectra. The second dissociation constant of 2,2-diquinolyl was determined by fluorimetric titration (_ex=336 nm, _em=420 nm), obtaining a value of 3.67±0.03. The triply charged 2,2,2-terpyridyl molecule was found to undergo the first dissociation atH ₀=–7.17±0.04, as determined by fluorimetric titration (_ex=316 nm, _em=350 nm), in aqueous sulfuric acid medium. Photometric titration (=335 nm) was performed in the presence of 6.5% ethanol because of the low solubility of the compound in water. In this ethanolicwater medium, a value of the dissociation constant atH ₀=–7.39±0.03 was calculated. The second dissociation constant was determined to be 2.81±0.12 by photometric titration at 285 nm, and values of 4.03±0.26 and 4.16±0.20 were found for the third dissociation constant by photometric titrations at 320 and 295 nm, in 10% ethanol, in close agreement with previously reported values. The fluorimetric titration profile obtained by exciting at 274 nm and measuring the fluorescence emission at 350 nm, in the zone betweenH ₀=–3 and pH=10, is complicated by the several equilibria involved.     

High-spin isomer in 93Mo

The high-spin states of ⁹³Mo have been studied by a ⁸²Se( ¹⁶O, 5n) ⁹³Mo reaction at a beam energy of 100 MeV using techniques of in-beam -ray spectroscopy. Measurements of -t, --t coincidences, -ray angular distributions and -ray linear polarizations were performed. The high-spin isomer was found as a (39/2^-) state at about 9.7 MeV. The near-yrast states in ⁹³Mo were interpreted using the weak-coupling picture of a d_5/2 neutron to a neutron magic core nucleus ⁹²Mo.     

Space Videophotometric System for Recording Optical Radiations in the Earth Atmosphere

This paper describes the VFS-3M videophotometric system designed for automatic remote recording of images and parameters of optical radiations following lightning discharges from aboard the Russian segment of the International space station. The characteristics of the system and the possibilities of recording such types of radiation as Red Sprites and Blue Jets are given.     

Calculation of the Tautomeric Properties of 3‐Formyl‐Tetrinic Acid by the ab initio and DFT Methods

We have carried out a nonempirical quantumchemical calculation with full optimization of the geometry of all theoretically possible tautomeric forms of 3formyltetrinic acid (FTRA) according to the Møller–Plesset secondorder perturbation theory with the use of a 6–31G(d) double zeta basis set. The correlation corrections to the total energy of molecules for optimized geometric configurations were calculated in the 631G(d,p) basis. All the possible tautomeric forms of FTRA and the harmonic vibrational frequencies were also calculated within the density functional theory (DFT) with the use of the Perdew–Burke–Ernzerhof (PBE) functional in a threeexponent basis. It is shown that FTRA in vapors (in the perfect gas approximation) exists in the form of a mixture of three enol forms, among which two exoforms predominate. The frequencies and forms of normal vibrations for each cisenol tautomer in the region of vibrations of ketogroups and double bonds differ widely, which permits identification of the tautomers present in the mixture. The possible mechanisms of enolenol transformations of 3acyltetrinic acids are discussed.     

Updated Analysis of Gallium Chelate and Vanadium Chelate Solutions with 4‐(2‐Pyridylazo)Resorcinol and Xylenol Orange

The characteristic factors of the gallium and vanadium chelates with the ligands 4(2pyridylazo)resorcinol (PAR) and xylenol orange (XO) have been determined with the aid of the principle of correction, which makes it possible to eliminate the influence of the surplus ligand in the solution of its chelate with methane (which makes calculation easier) and thereby provides a more acceptable method in comparison with others. The real molar coefficients of extinction of the chelates Ga and V with PAR and XO have been determined and a detailed calculation of the stoichiometric ratios of chelates has been made. The results have shown that the chelates formed have the following structure: Ga(PAR), Ga(XO), V(PAR)₂, and V(XO).     

Monte Carlo study of the ising model phase transition in terms of the percolation transition of “physical clusters”

Finite squareL×L Ising lattices with ferromagnetic nearest neighbor interaction are simulated using the Swendsen-Wang cluster algorithm. Both thermal properties (internal energyU, specific heatC, magnetization |M|, susceptibility) and percolation cluster properties relating to the physical clusters, namely the Fortuin-Kasteleyn clusters (percolation probability P , percolation susceptibility _p, cluster size distributionn _l) are evaluated, paying particular attention to finite-size effects. It is shown that thermal properties can be expressed entirely in terms of cluster properties, P being identical to |M| in the thermodynamic limit, while finite-size corrections differ. In contrast, _p differs from even in the thermodynamic limit, since a fluctuation in the size of the percolating net contributes to, but not to _p. NearT _c the cluster size distribution has the scaling properties as hypothesized by earlier phenomenological theories. We also present a generalization of the Swendsen-Wang algorithm allowing one to cross over continuously to the Glauber dynamics.     

The maximum entropy principle as a consequence of the principle of Laplace

The maximum entropy principle states that the probability distribution which best represents our information is the one which maximizes the entropy with the given evidence as constraints. We prove that this principle is implied from the Laplace principle of equiprobabilities applied to the setS of allN-term sequences of results which are compatible with the given evidence. We generalize to the information gain method of Kullback.     

Investigation of Rust Formed on Steel Surfaces and Related Oxyhydroxides

In order to indentity the corrosion products formed on steel surfaces from ⁵⁷Fe Mössbauer spectroscopy, detailed Mössbauer parameters have been determined for various kinds of iron-oxyhydroxides: -FeOOH, -FeOOH, -FeOOH and -FeOOH. ⁵⁷Fe Mössbauer measurements of the iron oxyhydroxides indicate the following results. Fe occupies a single site in -FeOOH, but below the Néel temperature as at e.g., 300 K the Mössbauer spectrum is always broad, showing a distribution of the strength of the magnetic exchange interactions. Its shape depends on the grain-size and synthetic methods of the specimen. Fe occupies 3 sites in -FeOOH. High-purity reagents of -FeOOH always contain small amounts of -FeOOH and their Néel temperatures depend on the synthetic methods of the specimen. Mössbauer spectroscopy of the synthetic -FeOOH shows very broad distribution of the hyperfine magnetic fields.     

Intersubjectivity,relativistic covariance,and conditionals: response to C. I. J. M. Stuart

A misunderstanding persists between Stuart and me, which I do my best to clarify. Bayesian inverse subjectivities versus relativistic covariance and physical intersubjectivity are discussed. A joint number of chances formalism taking care of the propagation of the probability of causes is proposed.     

High repetition rate CH4 laser

A 16-m CF₄ laser oscillator has operated at 1 kHz in a cooled static cell. Pump energies required from the low pressure, Q-switched, cw discharge CO₂ laser were as low as 60 J. The laser cavity employed a multiple-pass off-axis path resonator in a ring configuration. CF₄ laser power at 615 cm^–1 and a 1-kHz repetition rate exceeded 300 W.     

The correlation function in Wilson's theory of phase transitions: Above and below the transition

The correlation function and the correlation length are discussed in the theoretical framework of the Wilson-Feynman diagram expansion for small =4–d. It is shown explicitly that to order ² the scaling relation = (2–) is satisfied and that the correlation function is a homogeneous function ofk and . The explicit form of the scaled correlation function is exhibited.     

The βdecay of 147Cs to 147Ba

The ^--decay of ¹⁴⁷Cs to ¹⁴⁷Ba has been studied by means of - and X-ray spectroscopy. A new level scheme of ¹⁴⁷Ba is significantly modified and extended in comparison to the one previously reported. The Advanced Time-Delayed (t) method has been applied to measure half-lives of the 46.2 and 85.4 keV levels in ¹⁴⁷Ba yielding T_1/2 of 510(80) ps and 370(100) ps, respectively. The lifetime results combined with the deduced internal conversion coefficients allowed to assign M1 multipolarity to three transitions. The B(M1) values obtained for the 39.2, 46.2 and 85.4 keV transitions range from 0.017 to 0.043 W.u. and represent typical B(M1) strength in the Ba-Er region. Model calculations using a shell correction approach with the axially deformed Woods-Saxon potential predict for ¹⁴⁷Ba an octupole deformed ground state with ₃ = 0.11.     

Levels in <Superscript>127</Superscript>La fed by the <Superscript>127</Superscript>Ce beta-decay

The low-lying levels in ¹²⁷La have been studied through the -decay of ¹²⁷Ce ( T_1/2 = 29s) produced by bombarding a ^natMo target with a 185-MeV ³⁵Cl beam. Reaction products were on-line mass-separated, and -ray singles and - coincidence measurements were performed. Conversion electrons were also measured and multipolarities of transitions have been derived. The half-life of the 210.9-keV level was determined to be (1.9±0.3)ns by the - delayed coincidence technique. The level scheme obtained has been compared with calculations based on the Nilsson model.     

Collective structures of the <Superscript>131</Superscript>Cs nucleus

The collective structures of ¹³¹Cs have been investigated by in-beam -ray spectroscopic techniques following the ¹²⁴Sn (^11B , 4n) reaction at a beam energy E_lab = 57MeV. The previously established rotational bands, built on g_7/2, d_5/2 and the unique-parity h_11/2 orbitals, have been extended and evolve into new bands involving rotationally aligned (h_11/2)² and (h_11/2)² quasiparticles. In addition, a new multiquasiparticle band based on the g_7/2 g_7/2 h_11/2 configuration has also been observed. Theoretical interpretations for the assigned configurations are discussed in the framework of Total Routhian Surface (TRS) and Tilted Axis Cranking (TAC) model calculations. TAC model calculations predict a decrease in the B(M1) values with increasing rotational frequency for the g_7/2/d_5/2 (h_11/2)² and h_11/2 (h_11/2)² bands, thus indicating a magnetic rotation character for these bands.     

Influence of Thermal Annealing and Deposition Conditions on the Structure and Optical Properties of GRS‐Active Substrates Based on Silver Films

Using the methods of atomicforce microscopy, xray diffractometry, and spectrophotometry, we have studied the morphological, structural, and optical characteristics of GRSactive substrates based on original and annealed silver films. We show that the backing temperature during deposition is the factor which exerts the most substantial effect on the morphological and optical properties of silver films and also on their stability with time. The coefficients of the correlation of the deposition rate with the characteristics of the optical density spectra of silver films are calculated. It is found that hightemperature (350°C) annealing of a silver film leads to the selforganization of its surface into a quasiperiodic structure with semiellipsoidal islets. The contribution of the processes of excitation of plasma resonances to the formation of the optical density spectra is discussed. It is shown that as a result of thermal modification the concentration of the crystalline phase of silver in a silver film increases 2–3 times and also the dispersion of the orientation of crystallites decreases.     

Singular Perturbations of Self-Adjoint Operators

Singular finite rank perturbations of an unbounded self-adjoint operator A ₀ in a Hilbert space ₀ are defined formally as A ₍₎=A ₀+GG ^*, where G is an injective linear mapping from = ^d to the scale space _-k(A₀)k , kN, of generalized elements associated with the self-adjoint operator A ₀, and where is a self-adjoint operator in . The cases k=1 and k=2 have been studied extensively in the literature with applications to problems involving point interactions or zero range potentials. The scalar case with k=2n>1 has been considered recently by various authors from a mathematical point of view. In this paper, singular finite rank perturbations A ₍₎ in the general setting ran G – _k (A ₀), kN, are studied by means of a recent operator model induced by a class of matrix polynomials. As an application, singular perturbations of the Dirac operator are considered.     

Calculation of Quantum‐Chemical Characteristics of the Ground and Excited Electronic States of Porphin and Its Tetrapyrrole Isomers

Using the CNDO/S method, we have performed quantumchemical calculations of the ground and excited electronic states of porphin molecules (symmetry D _2h ) and a number of porphin isomers: porphycene (C_2h ), hemiporphycene, corphycene (C_2v ), isoporphycene, and three nonsynthesized structural isomers of the porphin skeleton by its bridge groups —(CH) _meso —. The results of the calculations are compared with the corresponding data for the freebase porphin molecule (H₂P). Near the boundary between the occupied and vacant orbitals the isomers form rows of singleelectron levels with similar energy characteristics. For the MOs of these isomers, the H₂P MOs closest in distribution on the comparable atomic centers are given. The weak (Q) and strong (B) transitions in the visible and near UV regions point to the porphyrin type of spectra of all the isomers. The calculation data on the excited electronic states of N, g, and ntype H₂P near and above the B states are given; the presence of such states in other isomers is shown. The calculation does not point to a difference in the position of the first singlet transitions in the first five isomers. The calculation data on the lower singlettriplet transitions are also reported.     

Interactions between dislocations and γ/γ' interfaces in superalloys

In situ transmission electron microscopy observations of the dislocation motion at vicinity of the /' interfaces in a Ni-base superalloy have been performed. They allow to identify the elemental mechanisms, under stress and at different temperatures, of the deformation propagation across the interfaces. It is shown that some of the mechanisms already analyzed in the literature occur. Moreover, new processes are revealed such as the formation of small dislocation pile-ups on the /' interfaces. Such a configuration, which increases the local stress, favors the overcoming of the interface.These observations together with new considerations on stresses are taken into account for proposing a new equilibrium equation for a dislocation abutting on a /' interface. This equation involves all the stress components acting on a dislocation: the applied stress, the misfit stress, the friction stress, the stress concentration due to the dislocation pile-up and the image stress.     

Role of Activator and Vacancy Centers in the Decay of the Gamma Scintillators of CsI–Na Crystals

The influence of the concentration of an activator (C _NaI) and of plastic deformation on a change in the contribution of a slow component to the decay of the -scintillations of CsI–Na crystals was investigated, as well as the influence of C _NaI on a change in the shape of the luminescence excitation spectrum in the region of absorption of activator centers (AC) and of vacancy-related centers (VRC) and also on a change in the intercenter time of deexcitation of the centers indicated. It is shown that AC and VRC participate in the photoluminescence and -scintillations of CsI–Na crystals. In the -scintillations, AC are responsible for the component ₁ = 370 nsec, whereas the components ₁ = 460 nsec and ₂ 2 sec are associated with VRC. The reduction of ₁ from 770 to 560 nsec with an increase in C _NaI from 2·10^–3 to 3·10^–2 mole% and from 570 to 470 nsec after plastic deformation of the crystals ( = 5%) along the 111 axis is caused by a decrease in the number of VRC. The mechanisms underlying the -scintillations of the CaI–Na crystals containing AC and VRC and also the decrease in the number of VRC are discussed.