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It is shown that, in the presence of a magnetic field, a quantized vortex line in a superfluid liquid acquires a linear polarization charge, which is localized near the vortex axis over a length on the order of the coherence length. It is found that the total charge of a rectilinear vortex is nonzero, while the vortex pair and vortex ring have a nonzero dipole moment. The electric fields of rectilinear vortices near the end surface of a cylindrical vessel filled with a superfluid liquid are calculated. The electric polarization of superfluid systems in the presence of thermally activated vortex pairs and vortex rings has been studied. It is shown that such a polarization arises in the presence of relative motion of the normal and superfluid components. [ABSTRACT FROM AUTHOR]

Strong driving of quantum systems opens opportunities for both controlling and characterizing their states. For theoretical studying of these systems properties we use the rate-equation formalism. The advantage of such approach is its relative simplicity. We used the formalism for description of a two-level system with further expanding it on a case of a multi-level system. Obtained theoretical results have good agreement with experiments. The presented approach can also be considered as one more way to explore properties of quantum systems and underlying physical processes such as, for instance, Landau–Zener–Stückelberg–Majorana transitions and interference. [ABSTRACT FROM AUTHOR]

The dislocation model of the supersolid state of 4He was proposed in 1987 by one of the authors of the review. The model obtained strong support by numerous experimental and theoretical investigations from 2007 to date. In these investigations, the validity of the idea put forward in 1987 was confirmed, and new conceptions of the superclimb of dislocations and of the giant isochoric compressibility or the syringe effect were proposed. In this paper, we review the main achievements of theoretical and experimental studies of a dislocation-induced supersolid and present current understanding of this phenomenon. [ABSTRACT FROM AUTHOR]

The article presents the information on different structural types of refractory products used for blowing metal in steel-teeming ladles and the key factors influencing their efficiency. The influence of basic refractory materials and their manufacture quality on the technological performance of the products is also evaluated. Based on continuous monitoring of the metal blowing efficiency, the structural types of argon-conducting units were determined, which are most consistent with the requirements of the technological process of cleaning steel in the steel-teeming ladles of the oxygen converter shop of the Magnitogorsk Iron and Steel Works PJSC. [ABSTRACT FROM AUTHOR]

Using coherent-state formalism (the Keldysh formalism), the article describes a transition from a homogeneous superfluid state to a supersolid state in a two-dimensional dilute gas of electron-hole pairs with spatially separated components. Such a transition is heralded by the appearance of a roton-type minimum in the collective excitation spectrum, which touches the abscissa axis as the distance between the layers or the pair density increases. This signals the instability of the system with respect to the appearance of a spatial modulation of the pair density. It has been found that a first-order transition to a hexagonal supersolid phase takes place a little earlier. A theory without phenomenological constants has been developed for an arbitrary relation between the effective masses of an electron and a hole. A phase diagram for the system has been plotted in the variables "the chemical potential of pairs – the distance between the layers." It has been shown that there is a jump in the average density of the condensate during the phase transition. It has been established that with an increase in the chemical potential, the inhomogeneous phase breaks up into high-density regions surrounded by lines at which the density becomes zero, with these lines forming a continuous network. [ABSTRACT FROM AUTHOR]

Crossed electric and magnetic fields influence dipolar neutral particles in the same way as the magnetic field influences charged particles. The effect of crossed fields is proportional to the dipole moment of the particle (inherent or induced). We show that this effect is quite spectacular in a multilayer system of polar molecules. In this system molecules may bind in chains. At low temperature the gas of chains becomes the superfluid one. The crossed fields then induce vortices in the superfluid gas of chains. The density of vortices is proportional to the number of particles in the chain. The effect can be used for monitoring the formation and destruction of chains in multilayer dipolar gases. [ABSTRACT FROM AUTHOR]

The thermal counterflow in superfluid helium placed in a magnetic field is shown to lead to the emergence of an electric field in the surrounding space. This effect is caused by the counterflow nature of thermal conductivity in superfluid systems: heat transfer in such systems is associated with the motion of the normal component, while the average mass flow transported by the normal component is compensated by the mass flow carried by the superfluid component. The local mass flow is nonzero. The effect occurs in case of stationary and non-stationary (second-sound) heat flows. The features of the effect for a number of samples with various geometries are considered. It was established that the magnitude of the arising electric field substantially depends on the shape of the sample containing helium and the direction of the magnetic field. [ABSTRACT FROM AUTHOR]

In the field stationary experiment, the dynamics of the general biological activity of chernozem, depending on the biomass of plant residues, methods of the basic soil tillage under different hydrothermal conditions was studied. It was established, that the release of carbon dioxide by microorganisms from the soil more intensively occurred on the background of deep tillage, where the best conditions for aeration and distribution of plant residues in the profile of the arable layer were found. Minimization of soil tillage, in consequence of the compaction of the arable layer by more than 1.3 g / cm³ limited the volume of active zone of biotic activity and growth processes of field crops in crop rotation while inhibiting the overall biological activity and reducing the amount of carbon dioxide released. However, small soil tillage contributed to the enhancement of the anti-erosion resistance of the chernozem surface from the shock energy of rain drops, and also provided more favorable conditions for the humification of organic residues instead of undesirable intensive mineralization, especially humus. [ABSTRACT FROM AUTHOR]

It has been shown that a heat flux induced by the temperature gradient ∇T in He-II placed in a magnetic field H generates an electric field E ∼ H × ∇T. The effect occurs in superfluid dielectric systems because of their heat superconductivity. The magnitude of the field significantly depends on the shape of a sample with helium and on the direction of the magnetic field with respect to the sample. It has been shown that the effect exists at both static and time dependent temperature gradient (at the propagation of the second sound). [ABSTRACT FROM AUTHOR]

It is predicted that oscillations of temperature during propagation of third sound in a thin superfluid film cause appearance of an alternating electric field in the surrounding space (a peculiar non-stationary thermoelectric effect). The magnitude of this field depends significantly on the substrate type and the method of its coating. It is shown that the differential thermal EMF (the ratio of electric potential amplitude to the film temperature amplitude) can exceed such one in metals and reach 10-4 V/K. [ABSTRACT FROM AUTHOR]

A method for shotcreting steel-pouring ladles under PAO MMK oxygen-converter workshop (OCW) conditions is described. Tests are conducted in the period 2018 – 2020. Results of the work performed are identification of operating parameters that affect wear of the working layer of the lining of steel-pouring ladles beneath the shotcrete layer, prospects for maintaining the lining by shotcreting in order to reduce lining working layer wear and as a result increase the life of PAO MMK OCW steel-pouring ladles. [ABSTRACT FROM AUTHOR]

• Quantum transport phenomena in magnetic fields in a highly mobile two-dimensional electron gas have been intensively studied for several decades. (iii) Superconducting quantum systems • Quantum engineering often deals with large structures of which the simulation is complicated. N. Chiang (Tszyan) I et al. i investigated the spin contributions to the Nernst-Ettingshausen, and Hall effects in metals with spin-orbit interaction. [Extracted from the article]

This review is devoted to the theory of electron-hole superfluidity in bilayer systems. This is a discussion of the state in which electrons and holes from adjacent layers form bound pairs, and a nondissipative transfer of charge is caused by the motion of pairs as wholes. The occurrence of the flow of bound pairs is equivalent to the flow in conducting layers of equal in modulus but oppositely directed electric currents. Therefore, such superfluidity can be examined as a unique superconductivity that is often called counterflow superconductivity. Although this phenomenon was predicted about 40 years ago, the intensive study of the problem of electron-hole superconductivity in bilayer systems continues to date. An extensive description of theoretical representations and approaches to the problem of electron-hole superconductivity is presented in this review. [ABSTRACT FROM AUTHOR]

We theoretically describe a driven two-electron four-level double-quantum dot (DQD) tunnel coupled to a fermionic sea using the rate-equation formalism. This approach allows to find occupation probabilities of each DQD energy level in a relatively simple way, compared to other methods. Calculated dependencies are compared with the experimental results. The system under study is irradiated by a strong driving signal, and as a result, one can observe Landau–Zener–Stückelberg–Majorana (LZSM) interferometry patterns which are successfully described by the considered formalism. The system operation regime depends on the amplitude of the excitation signal and the energy detuning, so one can transfer the system to the necessary quantum state in the most efficient way by setting these parameters. Obtained results give insights about initializing, characterizing, and controlling the quantum system states. [ABSTRACT FROM AUTHOR]

The polarization charge $$\rho _\mathrm {pol}$$ of an inhomogeneous superfluid system is expressed as a function of the order parameter $$\Phi (\mathbf{r}_1 ,\mathbf{r}_2 )$$ . It is shown that if the order parameter changes on macroscopic distances, the polarization charge $$\rho _\mathrm{pol} $$ is proportional to $$A\nabla ^2n$$ , and the polarization $$\mathbf{P}$$ is proportional to $$A\nabla n$$ , where n is the density of the system. For noninteracting atoms, the proportionality coefficient A is independent of density, and in the presence of interaction A is proportional to n. The change of the Bose gas density is found in the presence of a flow $$\mathbf{w}=\mathbf{v}_n -\mathbf{v}_s $$ passing the vortex. It is found that a vortex in a superfluid film creates an electric potential above the film. This potential has the form of a potential of a dipole, allowing to assign a dipole moment to the vortex. The dipole moment is a sum of two terms, the first one is proportional to the relative flow velocity $$\mathbf{w}$$ and the second one is proportional to $$\left[ {{\mathbf {\kappa }} \times \mathbf{w}} \right] $$ , where $$\mathbf{\kappa }$$ is the vortex circulation. [ABSTRACT FROM AUTHOR]

Prismatic sensors of two standard sizes are used to determine the heat-transfer coefficients of high-pressure nitrogen at different turbine rotor speeds of a SECO/WARWICK 10.0VPT-4020/24N vacuum furnace. The adequacy of the values obtained is estimated. [ABSTRACT FROM AUTHOR]

We predict that the propagation of the third sound in a film is accompanied by the emergence of the electric field in the surrounding space, which can be observed by modern methods. It has been shown that the influence of thermally activated vortices on this effect is weak even near the superfluid transition. [ABSTRACT FROM AUTHOR]

A study is made of complexly alloyed steel 8Kh4V9F2-Sh, which is used for fabricating parts of engineering bearings operating under extreme conditions. Vacuum processes are shown to be preferable to gas carburizing for hardening the races of precision bearings. Vacuum carburizing is shown to be an effective technique for forming quality diffusion layers. [ABSTRACT FROM AUTHOR]

The stability conditions for a superfluid phase in double layer systems with pairing of spatially separated electrons and holes were studied in the low density limit, and the general expression for the collective excitation spectrum was obtained. It was shown that as the distance d between the layers increases, a minimum appears in the excitation spectrum. When d reaches a critical value, the superfluid state becomes unstable with respect to the formation of a phase of the Wigner-crystal type. The same instability occurs at a fixed d upon an increase in the density of charge carriers. It was established that the critical distance and the critical density are related through inverse-power dependence. The impact of impurities on the temperature of the superfluid transition was investigated and the conditions under which it is small were established. It was shown that the critical temperature Tc ≈ 100K can be reached in the diluted systems. [ABSTRACT FROM AUTHOR]

We present a semiclassical theory for the delayed response of a quantum dot (QD) to oscillations of a coupled nanomechanical resonator (NR). We prove that the back action of the QD changes both the resonant frequency and the quality factor of the NR. An increase or decrease in the quality factor of the NR corresponds to either an enhancement or damping of the oscillations, which can also be interpreted as Sisyphus amplification or cooling of the NR by the QD. [ABSTRACT FROM AUTHOR]

We analyze a system composed of a qubit coupled to the electromagnetic fields in two high quality quantum oscillators. A particular realization of such a system is the superconducting qubit coupled to a transmission-line resonator driven by two signals with frequencies close to the resonator's harmonics. This doubly driven system can be described in terms of the doubly dressed qubit states. Our calculations demonstrate the possibility to change the number of photons in the resonator and the transmission of the fundamental-mode signal over a wide parameter range exploiting resonances with the dressed qubit. Experiments show that in the case of high quality resonators the dressed energy levels and corresponding resonance conditions can be probed, even for high driving amplitudes. The interaction of the qubit with photons of two harmonics can be used for the creation of quantum amplifiers or attenuators. [ABSTRACT FROM AUTHOR]

Classical deep level transient spectroscopy (DLTS) and its modification are used to study the time constants of electron capture by substitutional Cu atoms and thermal electron emission from Cu atoms in plastically deformed Cu-doped n-type germanium. The activation energy E, the electron capture cross-section, the energy E of the third acceptor level of Cu atoms, and the ionization entropy are determined. The lack of E-level broadening, the exponential capture kinetics for a filling-pulse duration of t ≲ 1 ms, the fact that the Cu-atom recombination parameters are independent of the dislocation density, and the low concentration of Cu atoms in the deformed samples suggest that the DLTS spectra are due to Cu atoms located outside the Read cylinders. [ABSTRACT FROM AUTHOR]

In the article by Shevchenko and A. S. Rukin, Pis'ma v Zh. Eksp. Teor. Fiz. 90, 46 (2009), it has been found that quantized vortices in superfluid systems acquire a charge in a magnetic field. A compensating charge with the opposite sign on a surface of the system can be at a macroscopic distance apart from the charge of the vortex. It is shown that as a result the total energy of the vortex charge and the compensating charge can be negative in the presence of an inhomogeneous electric field, normal to a homogeneous magnetic field. The conditions under which this leads to the spontaneous emergence of quantized vortices in the system are found. A possibility to observe the effect in He II, Bose gases of alkali metals and systems with spatially indirect excitons is discussed. [ABSTRACT FROM AUTHOR]

The approach by Ettore Majorana for non-adiabatic transitions between two quasi-crossing levels is revisited and significantly extended. We rederive the transition probability, known as the Landau–Zener–Stückelberg–Majorana formula, and introduce Majorana's approach to modern readers. This result, typically referred as the Landau–Zener formula, was published by Majorana before Landau, Zener and Stückelberg. Moreover, we go well beyond previous results and we now obtain the full wave function, including its phase, which is important nowadays for quantum control and quantum information. The asymptotic wave function correctly describes the dynamics away from the avoided-level crossing, while it has limited accuracy in that region. [ABSTRACT FROM AUTHOR]

The issue of adequate describing a gas of complex particles, composed of an even number of fermions, as point bosons is studied in alkali metals. In the low-density approximation we obtain the equation for the complex order parameter [uppercase_phi_synonym](r1, r2) representing the wave function of atoms with taking into account the internal motion of the valence electrons. For superfluid systems formed by particles with internal degrees of freedom, this equation replaces the Gross-Pitaevskii equation. It is shown that, in general, exchange effects should be considered in the same approximation as effects of the direct interaction of atoms with each other. In particular, in the case of only the Coulomb interaction the neglect of exchange effects leads to qualitatively incorrect results. The problem of spontaneous polarization in superfluid systems is studied. The expression for the electric polarization of the inhomogeneous superfluid system is obtained. [ABSTRACT FROM AUTHOR]

Two basic physical models, a two-level system and a harmonic oscillator, are realized on the mesoscopic scale as coupled qubit and resonator. The realistic system includes moreover the electronics for controlling the distance between the qubit energy levels and their populations and to read out the resonator's state, as well as the unavoidable dissipative environment. Such rich system is interesting both for the study of fundamental quantum phenomena on the mesoscopic scale and as a promising system for future electronic devices. We present recent results for the driven superconducting qubit-resonator system, where the resonator can be realized as an LC circuit or a nanomechanical resonator. Most of the results can be described by the semiclassical theory, where a qubit is treated as a quantum two-level system coupled to the classical driving field and the classical resonator. Application of this theory allows to describe many phenomena for the single and two coupled superconducting qubits, among which are the following: the equilibrium-state and weak-driving spectroscopy, Sisyphus damping and amplification, Landau-Zener-Stückelberg interferometry, the multiphoton transitions of both direct and ladder-type character, and creation of the inverse population for lasing. [ABSTRACT FROM AUTHOR]

We consider theoretically a superconducting qubit-nanomechanical resonator (NR) system, which was realized by LaHaye et al. [Nature (London) 459, 960 (2009)]. First, we study the problem where the state of the strongly driven qubit is probed through a frequency shift of the low-frequency NR. In the case where the coupling is capacitive, the measured quantity can be related to the so-called quantum capacitance. Our theoretical results agree with the experimentally observed result that, under resonant driving, the frequency shift repeatedly changes sign. We then formulate and solve the inverse Landau-Zener-Stiickelberg problem, where we assume the driven qubit's state to be known (i.e., measured by some other device) and aim to find the parameters of the qubit's Hamiltonian. In particular, for our system the qubit's bias is defined by the NR's displacement. This may provide a tool for monitoring of the NR's position. [ABSTRACT FROM AUTHOR]

The article discusses a study on the genesis of various hydrocarbon compounds and the possibility of their generation and migration from deep-seated carbon-rich fluid sources. The study identified soluble carbaceous materials (SCM) in the carbon-bearing metasomatites from the Arshan tectonic zone at the southeastern part of Sayan in Russia. The composition of SCM from rocks is described. It revealed that the rock samples contained complex organic compounds which can be indicative of CM.

It is shown that in a magnetic field the quantized vortices in a superfluid acquire a real quantized electric charge concentrated in the vortex core. This charge is compensated by an opposite surface charge, located at macroscopic distance from the vortex axis. It is found that polarization caused by the vortex velocity field does not give rise to electric fields outside an infinite cylinder. The vortex-created electric fields can be observed only near the cylinder end surfaces, which must be covered by dielectric covers in order to prevent leakage of the superfluid. The influence of cover properties on the vortex-created potential is studied here. The potentials created by vortices on point and ring electrodes are calculated. [ABSTRACT FROM AUTHOR]

In bilayer systems, electron-hole (e-h) pairs with spatially separated components can exhibit a transition to a superfluid state. An influence of random inhomogeneities on superfluid properties of bilayer systems is considered. It is shown that ionized impurities and distortions of conducting layers reduce the density of superfluid current of e-h-pairs. In the case when the interlayer distance is less than or of the order of magnetic length, the fluctuations of the interlayer distance lead to a significant decrease of the superfluid transition temperature. [ABSTRACT FROM AUTHOR]

The dissipative dynamics of a two-qubit system is studied theoretically. We make use of the Bloch-Redfield formalism which explicitly includes the parameter-dependent relaxation rates. We consider the case of two flux qubits, when the controlling parameters are the partial magnetic fluxes through the qubits' loops. The strong dependence of the interlevel relaxation rates on the controlling magnetic fluxes is demonstrated for the realistic system. This allows us to propose several mechanisms for lasing in this four-level system. [ABSTRACT FROM AUTHOR]

Works devoted to the study and introduction of polymer quenching media in the last 10 years are analyzed. Results of operation of known polymer quenchants are presented. Properties of new polymer-based media are considered. [ABSTRACT FROM AUTHOR]

A detailed theory for a system of a superconducting qubit coupled to a transmission line resonator is presented. We describe the system by solving analytically and numerically the master equation for the density matrix, which includes a dissipative Lindblad term. We calculate the transmission coefficient, which provides a way to probe the dressed states of a qubit. The theoretical results are related to experiments with intermediate coupling between a qubit and a resonator when the coupling energy is of the same order as the qubit relaxation rate. [ABSTRACT FROM AUTHOR]

The article focuses on the investigation of radiative heat transfer using Surinov method. It compares the Gebhart method from that of Surinov in radiative heat transfer calculation. It also determines the distribution of density of effective radiation flux on the plates' surface. It states the importance of the estimation of error to compare the calculated heat transfer in a system. Moreover, it presents equations in calculating the effective and resultant radiation fluxes.

The electric polarization appearing in superfluid systems as a result of their inhomogeneity is studied. The problem is studied using the rarefied electron-hole gas model which the authors studied previously. A microscopic calculation is performed of the polarization of quantum vortices in the absence and presence of a magnetic field. It is established that in the presence of a magnetic field vortices acquire additional polarization, which results in the appearance of a quantized charge in a vortex core. It is shown that the van-der-Waals interaction of a superfluid system with a solid surface gives rise to polarization near the surface. A relation is established between the results obtained and the prediction of possible polarization of the medium in nonuniform motion. [ABSTRACT FROM AUTHOR]

Keldysh’s theory of a rarefied superfluid electron-hole gas is extended to the case of possible pair polarization. It is established that the complex order parameter [uppercase_phi_synonym](r1,r2), which is the wave function of a pair, satisfies a nonlinear, nonlocal, integrodifferential equation. The equation obtained is solved for the order parameter varying slowly over a distance of the order of the pair size. The dipole-moment density of the system is found from the known function [uppercase_phi_synonym](r1,r2), and it is shown that the inhomogeneity of the system engenders a dipole moment proportional and oriented parallel to the gradient of the particle density. It is determined that an additional dipole moment associated with pair polarization due to the Lorentz force appears in a magnetic field. [ABSTRACT FROM AUTHOR]

The local quasiparticle density of states in the current-carrying d-wave superconducting structures is studied theoretically. The density of states can be accessed through the conductance of the scanning tunneling microscope. Two particular situations are considered: the current state of a homogeneous film, and a weak link between two current-carrying d-wave superconductors. [ABSTRACT FROM AUTHOR]

The Keldysh theory of the superfluidity of a diluted electron-hole gas has been generalized to the case of the possible polarization of the pairs. It has been shown that the inhomogeneity of the system induces the dipole moment, which appears near the system boundaries and is proportional to the gradient of the particle density. It has been found that the quantized vortices in the magnetic field carry a real electric charge. The charge density in He II rotating at a rate of 102s−1 in a magnetic field of 10 T is about 104 e cm−3, where e is the elementary charge. [ABSTRACT FROM AUTHOR]

A superfluid state can arise in bilayer systems as a result of pairing of spatially separated electrons and holes. In the limit of low electron–hole pair density the superfluid state can be described by a nonlinear dynamical equation. In the present paper a microscopic derivation of such an equation for the wave function of the electron–hole pair condensate in a strong magnetic field is presented. This equation is generalized to the cases where an electric field is applied to the system and where the composition of the semiconductor forming conducting layers varies in space. The solution of the dynamical equation gives the frequencies of the characteristic oscillations of the electron–hole pair condensate in excitonic traps produced by electric charge or variation of the composition of the semiconductor. [ABSTRACT FROM AUTHOR]

The Bose–Einstein condensation of vacancies in a three-dimensional decorated lattice is considered. The model describes possible scenario of superfluidity of solid helium, caused by the presence of zero-point vacancies in a dislocation network. It is shown that the temperature of Bose–Einstein condensation decreases under increase of the length of the network segments, and the law of decrease depends essentially on the properties of the vertices of the network. If the vertices correspond to barriers with a small transparency, the critical temperature varies inversely as the square of the length of the segment. On the contrary, if the vertices correspond to traps for the vacancies (it is energetically preferable for the vacancies to be localized at the vertices), an exponential lowering of the temperature of transition takes place. The highest temperature of Bose–Einstein condensation is reached in the intermediate case of vertices with large transparency, but in the absence of tendency of localization at them. In the latter case the critical temperature is inversely as the length of the segment. [ABSTRACT FROM AUTHOR]

The cooling capacity of aqueous solutions of polymer compositions based on polycarboxylic acids and copolymers of N-vinyl amides is studied. Tests of a new quenchant based on interpolymer complexes of anion-active components are performed and the process possibilities and the reproducibility of properties of different batches of this quenchant are estimated. [ABSTRACT FROM AUTHOR]

The impedance measurement technique consists in that the phase-dependent (parametric) inductance of the system is probed by the classical tank circuit via measuring the voltage. The notion of the parametric inductance for the impedance measurement technique is revisited for the case when a quantum system is probed. Measurement of the quantum state of the system of superconducting circuits (qubits) is studied theoretically. It is shown that the result of the measurement is defined by the partial energy levels population in the qubits and by its derivative. [ABSTRACT FROM AUTHOR]

The magnetic susceptibility of Nd2O3, NdCo1 + x O3, and LaCo1 + x O3 ( x = 0, 0.05, 0.1, 0.15) has been measured at temperatures from 80 to 950 K, and the electrical conductivity of the neodymium and lanthanum cobaltites (enriched in cobalt relative to neodymium or lanthanum) with the general formulas Nd(La)Co1 + x O3 + 1.5 x , or Nd1/(1 + x)(La)1/(1 + x)CoO(3 + 1.5 x)/(1 + x), has been measured between 300 and 1050 K. The effective magnetic moments of paramagnetic ions have been determined in the temperature ranges of CurieWeiss behavior and have been used to evaluate the fractions of low-, intermediate-, and high-spin Co3+ ions. Raising the temperature from 320 to 660 K (non-Curie—Weiss behavior) increases the fraction of high-spin Co3+ ions in LaCo1 + x O3 + 1.5 x (La1/(1 + x)CoO(3 + 1.5 x)/(1 + x) from 27–43 to 56–61%. Moreover, in this temperature range the conductivity of the lanthanum cobaltites rises most steeply. In the range 660–950 K, no spin transition occurs in LaCo1 + x O3 + 1.5 x , the slope of the conductivity versus temperature curves gradually decreases, and the conductivity gradually saturates. The conductivity of NdCo1 + x O3 + 1.5 x (Nd1/(1 + x)CoO(3 + 1.5 x)/(1 + x)) varies considerably in the range 550–950 K, and the spin transition in these cobaltites takes place between 260 and 760 K. Above 760 K, the NdCo1 + x O3 + 1.5 x cobaltites with x = 0.05 and 0.10 contain, respectively, 72 and 83% high-spin Co3+ ions and 28 and 17% high-spin Co4+ ions, whereas neodymium cobaltite with x = 0.15 contains 83% high-spin and 17% intermediate-spin Co3+ ions. [ABSTRACT FROM AUTHOR]

The problem of the charge sensitive preamplifier (CSPA) saturation is considered. It is shown that statistical uncertainty of the CSPA saturation time intervals is small in real measurements and it is possible to apply a periodical programmable external reset of CSPA (as well as programmable protection of other electronic blocks in a spectrometer against distortions caused by the preamplifier reset pulse) without essential increase of the dead time. [ABSTRACT FROM AUTHOR]

The conditions for formation of a bound state between two-dimensional spatially separated electron and hole in a magnetic field normal to the plane of motion of the carriers are investigated. The binding energy, effective mass, and electric polarizability of the electron-hole pair are found as functions of the distance d between conducting layers. The features of the superfluidity of a Bose gas of electron-hole pairs in the case of low density are analyzed. It is established that quantized vortices in the superfluid phase have real electric charge, the value of which depends on the density of pairs and the distance between layers. In the case of small d and high magnetic fields the vortex charge q=νe, where ν is the filling factor of the lowest Landau level by carriers. The stability of the Bose gas of pairs against transition to the crystalline state is investigated, and it is shown that at small d the pair crystallization temperature Tm is substantially below the superfluid transition temperature Tc. With increasing d the temperature Tm grows more rapidly than Tc, and there exists a critical value d at which the superfluid phase vanishes. © 2005 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We study the dynamic behavior of a quantum two-level system with periodically varying parameters by solving numerically the master equation for the density matrix. Two limiting cases are considered: multiphoton Rabi oscillations and Landau–Zener transitions. The approach is applied to the description of the dynamics of superconducting qubits. In particular, the case of the interferometer-type charge qubit with periodically varying parameters (gate voltage or magnetic flux) is investigated. The time-averaged energy level populations are calculated as functions of the qubit’s control parameters. © 2005 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Potential interaction surface of polyhydrated monomethyl mercury cation with inorganic ligands (X = Cl, Br, I, HO, HS, HSe) has been studied by quantum chemical methods. Thermodynamic and kinetic parameters of complexation processes were determined. A relative stability of polyhydrated complexes (Me-Hg—X) to the dissociation of coordination bond Hg—X was found to increase in the series: HO ≪ I < Br < HS < HSe < Cl. [ABSTRACT FROM AUTHOR]

The article presents information on Viacheslav Ivanovich Khanzhin, who became the procurator of Tula Oblast, Russia, at the end of November 2001. The difference between Tula Oblast and other regions is that here a large part of the military-industrial complex was concentrated. After the well-known decline, many factories ground to a halt for lack of state orders. Khanzhin's strong scientific base collapsed and many institutes were wound up. A not completely correct policy played a role in this, when they tried to destroy the mines. Interested parties even paid the workers to flood the mines with water: that way they got rid of their competitors. Because coal is supplied to several electricity plants.

Quantum chemical methods were used to investigate the mechanism of interaction of polyhydrated Hg(II) with methylcobalamin — a derivative of vitamin B12. Migration of the methyl group in the B12·Hg(II) nH2O cluster, initiating the formation of methylmercury, is considered. The reaction of substitution of methylmercury for the cobalt atom in the corrin fragment of B12 has been studied. The thermodynamic and activation characteristics of these processes have been obtained. The mercury analog of vitamin B12 is shown to exist in two radically different conformations. [ABSTRACT FROM AUTHOR]