A Modified Scheme of Triplectic Quantization

A modified version of triplectic quantization, first introduce by Batalin and Martnelius, is proposed which makes use of two independent master equations, one for the action and one for the gauge functional such that the initial classical action also obeys that master equation.Comment: 8 page

UV continuum emission and diagnostics of hydrogen-containing non-equilibrium plasmas

For the first time the emission of the radiative dissociation continuum of the hydrogen molecule ($a^{3}\Sigma_{g}^{+} \to b^{3}\Sigma_{u}^{+}$ electronic transition) is proposed to be used as a source of information for the spectroscopic diagnostics of non-equilibrium plasmas. The detailed analysis of excitation-deactivation kinetics, rate constants of various collisional and radiative transitions and fitting procedures made it possible to develop two new methods of diagnostics of: (1) the ground $X^{1}\Sigma_{g}^{+}$ state vibrational temperature $T_{\text{vib}}$ from the relative intensity distribution, and (2) the rate of electron impact dissociation (d[\mbox{H_{2}}]/dt)_{\text{diss}} from the absolute intensity of the continuum. A known method of determination of $T_{\text{vib}}$ from relative intensities of Fulcher-$\alpha$ bands was seriously corrected and simplified due to the revision of $d \to a$ transition probabilities and cross sections of $d \gets X$ electron impact excitation. General considerations are illustrated with examples of experiments in pure hydrogen capillary-arc and H$_{2}$+Ar microwave discharges.Comment: REVTeX, 25 pages + 12 figures + 9 tables. Phys. Rev. E, eprint replaced because of resubmission to journal after referee's 2nd repor

Ising-like Spin Anisotropy and Competing Antiferromagnetic - Ferromagnetic Orders in GdBaCo_{2}O_{5.5} Single Crystals

In RBaCo_{2}O_{5+x} compounds (R is rare earth), a ferromagnetic-antiferromagnetic competition is accompanied by a giant magnetoresistance. We study the magnetization of detwinned GdBaCo_{2}O_{5.5} single crystals, and find a remarkable uniaxial anisotropy of Co^{3+} spins which is tightly linked with the chain oxygen ordering in GdO_{0.5} planes. Reflecting the underlying oxygen order, CoO_2 planes also develop a spin-state order consisting of Co^{3+} ions in alternating rows of S=1 and S=0 states. The magnetic structure appears to be composed of weakly coupled ferromagnetic ladders with Ising-like moments, which gives a simple picture for magnetotransport phenomena.Comment: 5 pages, 4 figures, accepted to Phys.Rev.Let

Funkcionalne mreže za ergonomiju i zadaci pouzdanosti u povodu 90. godišnjice A. Gubinskyja i V. Evgrafova

The paper considers the tasks of discovering ergonomic reserves for increasing the reliability and efficiency of automated systems. The authors show the necessity of using the Activity Approach and the Theory of Functional Networks, developed by the scientific school of Professor Anatoly Ilyich Gubinsky. The authors describe the history of Functional Networks approach and the current state of development of the functional networks models and show the possibilities for automating the assessment of reliability of human-machine interactions. The research describes the common ergonomics issues and its effective solution by the introduction of automated procedures for the analysis and evaluation of functional networks. The authors further present the ways of using the developed models in decision support systems in the automated systems design and operation.U radu se razmatraju zadaci otkrivanja ergonomskih rezervi za povećanje pouzdanosti i učinkovitosti automatiziranih sustava. Autori pokazuju nužnost korištenja pristupa aktivnosti i teorije funkcionalnih mreža, koje je razvila znanstvena škola profesora Anatolyja Ilyich Gubinsky. Autori opisuju povijest pristupa funkcionalnih mreža i trenutno stanje razvoja modela funkcionalnih mreža te prikazuju mogućnosti automatizacije procjene pouzdanosti interakcija čovjek-stroj. Istraživanje opisuje uobičajena pitanja ergonomije i njezino učinkovito rješenje uvođenjem automatiziranih postupaka za analizu i evaluaciju funkcionalnih mreža. Autori nadalje predstavljaju načine korištenja razvijenih modela u sustavima za podršku odlučivanju u projektiranju i radu automatiziranih sustava

Photoconductive detection of hydrogen in ZnO and rutile TiO2

Hydrogen donors in ZnO and rutile TiO2 are probed by means of photoconductivity and IR absorption. It is shown that the O–H bonds giving rise to the local vibrational modes (LVMs) of interstitial hydrogen at 3611 and 3290 cm−1 in the case of ZnO and TiO2, respectively, also occur in the photoconductivity spectra as Fano resonances. The effects of isotope substitution, concentration, sample thickness, influence of other donors present in both oxides are considered. Based on the shape and frequency of these resonances, it is concluded that the apparent ionization energy of interstitial hydrogen in rutile TiO2 is less than 300 meV. By a direct comparison, we also demonstrate that photoconductive detection of LVMs of defects in thin semiconductor films is superior to the standard IR absorption

Magnetotransport Properties of Antiferromagnetic YBa_2Cu_3O_6.25 Single Crystals

In-plane and out-of-plane magnetoresistivities (MR) of antiferromagnetic YBa_2Cu_3O_6.25 single crystals were measured in magnetic fields H applied along the (ab) plane. In-plane MR is a superposition of two components: The first component is strongly in-plane anisotropic, changing sign from negative when H is parallel to the electrical current I to positive when H is perpendicular to I. The second component is positive, quadratic in H, and isotropic in the (ab)-plane. The out-of-plane MR displays a fourfold symmetry upon in-plane rotation of the magnetic field, with maxima along the easy axes of antiferromagnetic spin ordering and minima along unfavorable directions of spin orientation (45 degrees from the Cu-O-Cu bonds).Comment: 8 pages, 4 figure

Normal-state resistivity anisotropy in underdoped RBa_2Cu_3O_{6+x} crystals

We have revealed new features in the out-of-plane resistivity rho_c of heavily underdoped RBa_2Cu_3O_{6+x} (R=Tm,Lu) single crystals, which give evidence for two distinct mechanisms contributing the c-axis transport. We have observed a crossover towards "metal-like" (d rho_c/d T > 0) behavior at the temperature T_m which quickly increases with decreasing doping. The "metal-like" conductivity contribution dominates at T < T_m and provides a saturation of the resistivity anisotropy, rho_c / rho_{ab}. The antiferromagnetic ordering is found to block this "metal-like" part of the c-axis conductivity and complete decoupling of CuO_2 planes, which may be the reason of superconductivity disappearance.Comment: RevTex, 4 pages including 4 eps figures. To be published in Phys.Rev.Let

On the method of photoconductive detection of defects in semiconductors by vibrational mode-related Fano resonances

The method of photoconductive detection of defect-related vibrational modes in semiconductors by Fano resonances is validated by a combined photoconductivity and infrared absorption study of the interstitial hydrogen donor in ZnO. Depth-resolved isotopic substitution experiments with varying concentrations of H and D show that the effect of vibrational mode-related absorption has to be taken into account in order to allow for an unambiguous interpretation of the experimental data. A quantitative model is presented which describes the influence of sample thickness, defect concentration, and the presence of other donors on the sign, magnitude, and shape of the Fano resonances. Implications for the photoconductive detection of defect-related vibrational modes are discusse