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Purpose. The purpose of this paper is to include comparison of results of the modeling and calculation in the Mentor Siemens software MotorSolve and experiment of the brushless permanent magnet motor. Methodology. Numerical investigation using licensed software MotorSolve is performed. Calculations of motor parameters and characteristics are made using Finite Element Method. The experimental investigations were made on the hysteresis dynamometer AHD-603. Results. The results of the investigations show that the calculations of the parameters and characteristics of the motor in MotorSolve software almost match with the results of the experiments. Practical value. The high efficiency of the MotorSolve software for the modeling, calculation and research of the brushless permanent magnet motors are confirmed., Рассмотрены некоторые возможности программного комплекса MotorSolve для моделирования и анализа вентильных двигателей с постоянными магнитами. Представлены результаты расчета параметров и характеристик вентильного двигателя с известными геометрическими размерами и обмоточными данными статора. Результаты расчета сопоставлены с результатами экспериментальных исследований.

We report the observation of oscillatory redox reactions on the surface of multilayer graphene oxide (GO) films at room temperature. The redox reactions exhibited dampened oscillatory behavior with a period of about 5 days and were found to be dependent on the time elapsed from film deposition. The kinetic behavior observed for the oxidation–reduction reactions and the metastability of the surface functional groups are adequately described by two models involving GO reactions and reactant diffusion.

In situ optical diagnostics are used to reveal the isothermal nucleation and growth mechanisms of graphene on Ni across a wide temperature range (560 C < T < 840 C) by chemical vapor deposition from single, sub-second pulses of acetylene. An abrupt, two-orders of magnitude change in growth times (~ 100s to 1s) is revealed at T = 680 C. Below and above this temperature, similar sigmoidal kinetics are measured and attributed to autocatalytic growth reactions but by two different mechanisms, surface assembly and dissolution/precipitation, respectively. These data are used to develop a simple and general kinetic model for graphene growth that includes the nucleation phase and includes the effects of carbon solubility in metals, describes delayed nucleation, and allows the interpretation of the competition between surface and bulk growth modes. The sharp transition in growth kinetics at T = 680 C is explained by a change in defect site density required for nucleation due to a transition in the carbon-induced mobility of the Ni surface. The easily-implemented optical reflectivity diagnostics and the simple kinetic model described here allow a pathway to optimize the growth of graphene on metals with arbitrary carbon solubility.

Modern methods for the treatment of malignant brain tumors are insufficiently effective. One reason for this is that the existing technologies and methods are focused on removing all neoplastic cellsfrom the body. Understanding the mechanisms of systemic migration of stem cells provides a new view on the role of this phenomenon in the development of malignant tumors. Migration and homing of normal stem cells, being originally the regulatory process, ensuring revascularization and remodeling of ischemic or traumatic injury of brain, play a role of the axial conductor of neoplastic process in carcinogenesis. The use of the phenomenon of migration and homing of stem cells in the tumor center for therapeutic purposes opens the possibility of overcoming the blood-brain barrier, reducing the toxicity of chemotherapy and increasing the radiation therapy efficiency, makes possible the directed influence on the hypoxic zone of the tumor, can directly affect to the key life processes of tumor stem cells. These arguments allow to consider the mechanisms of systemic migration and homing of stem cells to neoplastic foci as a fundamental theoretical platform for the creation of a fundamentally new class of anti-cancer, cell personalized medicines.

A theoretical model is presented that explains spontaneous changes in the crystalline orientation of nanoparticles. The spontaneous changes in crystalline orientation are attributed to the crystal anisotropy of the surface energy of nanocrystalline particles. We consider an important specific case of the chemical vapor deposition growth of carbon nanofibers, where previous studies have shown that both the catalyst nanoparticle shape and the nanofiber growth rate change with changes in the chemical potential of diluted carbon. Energetic considerations of the nanoparticle’s free surface and its interfacial energy with the nanofiber during these shape changes are shown to force a reorientation of the nanoparticle crystallographic axes at a critical growth rate. The model therefore reveals the mechanism by which the shape and crystallographic orientation of the catalyst nanoparticle are linked to the nanofiber growth rate. The model suggests a new way, based upon measurable geometry of nanoparticles during in situ growth experiments, to estimate the role of chemisorption in the attraction of the graphene film to the curved catalyst surface and the anisotropy energy of this interface.

The policy documents devoted to advancement of science in Russia for the period till 2020 set a national goal to raise the level of competitiveness of national universities, research centers and research teams up to the world level. To achieve this goal we need to acknowledge the necessity to adopt the universally recognized criteria for assessment of a scientist's performance and to main- tain the highest standards of the national education and research activities. This article presents the results of analysis of compliance of Russian research works with the world standards of quali- ty and effectiveness. The analysis is based on materials of the international conference "Science online: online resources for science and education" and publications in Internet.

Silicon nanowire and nanopillar structures have drawn increased attention in recent years due in part to their unique optical properties. Herein, electron beam lithography combined with reactive-ion etching is used to reproducibly create individual silicon nanopillars of various sizes, shapes, and heights. Finite difference time domain analysis predicts local field intensity enhancements in the vicinity of appropriately sized and coaxially illuminated silicon nanopillars of approximately 2 orders of magnitude. While this level of enhancement is modest when compared to plasmonic systems, the unique advantage of the silicon nanopillar resonators is that they enhance optical fields in substantially larger volumes. By analyzing experimentally measured strength of the silicon Raman phonon line (500 cm(-1)), it was determined that nanopillars produced local field enhancements that are consistent with these predictions. Additionally, we demonstrate that a thin layer of Zn phthalocyanine on the nanopillar surface with a total amount of30 attomoles produced prominent Raman spectra, yielding enhancement factors (EFs) better than 2 orders of magnitude. Finally, silicon nanopillars of cylindrical and elliptical shapes were labeled with different fluorophors and evaluated for their surface-enhanced fluorescence (SEF) capability. The EFs derived from analysis of the acquired fluorescence microscopy images indicate that silicon nanopillar structures can provide enhancements comparable or even stronger than those typically achieved using plasmonic SEF structures without the limitations of the metal-based substrates, such as fluorescence quenching and an insufficiently large probe volume. It is anticipated that dense arrays of silicon nanopillars will enable SEF assays with extremely high sensitivity, while a broader impact of the reported phenomena is anticipated in photovoltaics, subwavelength light focusing, and fundamental nanophotonics.

Comparative assessment of the efficacy and safety of enoxaparin and dabigatran thromboprophylaxis after total hip arthroplasty was performed. Hemorrhagic and thrombotic complications as well as indices of laboratory tests after application of new oral thrombin inhibitor Dabigatran Etexilate were taken into account. Study included 161 patients who were randomized into two groups and operated on under spinal anesthesia. First group (81 patients) was on subcutaneous enoxaparin (40 mg/day), second group (80) was on dagibartan (200 mg/day). The day before surgery and on 5th and 10th days after arthroplasty duplex angioscanning of lower extremities and assessment of blood clotting parameters was performed. It was shown that in case of significant intraoperative blood loss thromboprophylaxis with both enoxaparin and dabigatran was similar to that with low-molecular-weight heparin. Postoperative thrombogenic risk by D-dimers level was higher with enoxaparin versus dabigatran application. Peroral use of anticoagulants is more acceptable due to its noninvasiveness, safety, low requirements in laboratory monitoring and convenience of application in out-patient conditions. In patients with low compliance testing of blood plasma thrombin can be used for the confirmation of dabigatran intake when necessary.

A review is given on the recent studies of spin dynamics in diluted magnetic semiconductor quantum wells. The experiments are using time-resolved photoluminescence techniques to study: spin–lattice relaxation of magnetic Mn 2+ ions; spin interaction between free carriers and magnetic ions; spin diffusion in the magnetic ion system.

The magnetization kinetics in (Zn,Mn)Se/(Zn,Be)Se quantum wells is studied on a ps-time scale after pulsed laser excitation. The magnetization induced by an external magnetic field is reduced by up to 30% within about 100 ps due to spin and energy transfer from photocarriers to magnetic Mn ions. A model based on spin-momentum coupling in the valence band is suggested for explaining this transfer.

The work is an experimental study of optical spin polarization in InAs/GaAs quantum dots (QDs) with 2 resident electrons or holes. A capture of a photo-generated electron-hole pair into such a QD creates a negative or positive tetron (double-charged exciton). Spin polarization was registered by the circular polarization of the QD photoluminescence (PL). The spin state was found to differ radically in the dots with opposite in sign charge. Particularly, under excitation in a GaAs barrier, the ground state PL polarization is negative (relative to the polarization of an exciting light) in the negatively charged QDs and positive in the positively charged QDs. With increasing excitation intensity, the negative polarization rises from zero up to a saturation level, while the positive polarization decreases. The negative polarization increases in weak magnetic fields applied in Faraday geometry, but strong fields suppress it. The positive polarization always increases as a function of magnetic field. We propose a theoretical model that qualitatively explains the experimental results.

The behavior of the optical-orientation signal under resonant optical excitation of localized excitons in quantum wells with semimagnetic layers was studied both experimentally and theoretically. The most remarkable experimental observation made in this study is the increase in the degree of polarization of the quantum well radiation in the conditions in which the Hanle effect is observed. The behavior of magnetically induced circular luminescence polarization in a slightly tilted field (quasi-Voigt geometry) also appears unusual. Possible specific contributions to the optical exciton orientation in semimagnetic nanostructures are discussed. A theoretical model is proposed which, while being based on the well-known concepts of collective spin dynamics of magnetic ions in the exchange field of a photoexcited hole, takes into account fluctuations of the local magnetization. The calculations agree quantitatively with experiment for reasonable values of the parameters.

Fine and hyperfine splittings arising from electron, hole, and nuclear spin interactions in the magnetooptical spectra of individual localized excitons are studied. We explain the magnetic field dependence of the energy splitting through competition between Zeeman, exchange, and hyperfine interactions. An unexpectedly small hyperfine contribution to the splitting close to zero applied field is described well by the interplay between fluctuations of the hyperfine field experienced by the nuclear spin and nuclear dipole/dipole interactions.

Confinement of vibronic excitations in semiconductor nanocrystal (NC) quantum dots (QDs) has become a subject of intensive studies in recent years. In this paper we demonstrate the possibility of constructing the spherical QD acoustic phonon eigenmodes by use of nothing but symmetry analysis and apply this treatment to the specific case of CuCl NCs.

It is shown that the mixed character of spheroidal vibrational modes of semiconductor quantum dots of spherical shape may lead to the appearance of a line in the low-frequency Raman spectra of nanocrystals whose spec-tral position is independent of the average radius of nanocrystals in the sample over a wide range of sizes. This effect is associated with the rapid saturation of the dispersion dependence for transversal acoustic phonons in the bulk semiconductor. The maximum radius of quantum dots at which the line indicated above is observed in the spectrum has been estimated.

We review results of magnetooptical studies related to various methods of spin splitting engineering possible in quantum well (QW) structures made of II-VI diluted magnetic semiconductors (DMS). The experiments made use of unique structures, based on Cd 1-x-y Mn x Mg y Te, with a precise in-plane profiling of either QW width or n-type doping intensity and of structures with digital profiling of the composition of constituent materials in the growth direction. The most typical version of the spin splitting engineering, available also in bulk DMSs, namely the one via an adjustment of (homogeneous) Mn composition, or via the lattice temperature or/and a magnetic field, was used to study magnetooptical properties of QW containing electrons as a function of their g-factor (tuned from g * eff = - 1.46 to + 55!). We also demonstrate three further methods of modifying the spin splitting in low-dimensional structures made of DMSs. They involve: (i) atomically precise control over Mn ion spatial distribution in the growth direction, (ii) reduction of the s-d exchange constant with increasing electron confinement, (iii) modification of Mn spin temperature by the electron gas heated by photo-excited carriers.

We observed a giant splitting of exciton spin sublevels in CdS nanocrystals, each doped on the average by one Mn ion. The splitting, which exists in zero external magnetic field, is caused by the gigantic internal magnetic field of the Mn ion and results from the enhancement of the short range spin–spin interactions in nanocrystal quantum dots. The splitting is seen in the strong magnetic circular dichroism of the CdS band edge transitions. The magnitude of the observed band edge splitting is in good agreement with a theoretical calculation of the effective magnetic field.

It is shown that, within deep narrow quantum potential wells in systems based on semimagnetic semiconductors containing Mn2+ ions, both magnitude and sign of the exchange interaction between electrons in the conduction band and in the d-shell of a magnetic ion depend significantly on the spatial position of this ion. This situation allows magnetic polarons with zero magnetic moment to appear, for which the localized-electron-induced spatial distribution of polarization of the surrounding magnetic ions exhibits an antiferromagnetic character. The possibility of experimental detection of these “nonmagnetic” magnetic polarons is considered.

Peculiarities of optical spectra in diluted magnetic semiconductors are used to find out the characteristic size of the localized exciton state in ${\mathrm{Cd}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{Te}$ alloys. Three methods for evaluation of the exciton localization radius are suggested. Two of them are based on spin-related phenomena. The localization radius is calculated from measured magnetic-polaron energies and from the degree of the magnetic-field-induced circular polarization of luminescence. The exciton localization radius is determined for a set of samples with Mn content varying from 0.1 up to 0.4. The results of the two spin-related methods are in good agreement to each other. Their comparison with the results of the third approach based on the exciton linewidth analysis allows the conclusion that both the electron and hole of the exciton are localized within the same volume. This latter method, verified by comparison with two others, is applicable also to a wider class of semiconductor compounds which do not contain magnetic impurities.

We provide an experimental evidence and a theoretical substantiation for a strong reduction of the $s\ensuremath{-}d$ exchange interaction between electrons and Mn-ion spins with increasing degree of the confinement in nanostructures of diluted magnetic semiconductors. By spin-flip Raman scattering a strong (up to $25%$) reduction of the exchange parameter is observed in $(\mathrm{Cd},\mathrm{Mn})\mathrm{Te}/(\mathrm{Cd},\mathrm{Mn},\mathrm{Mg})\mathrm{Te}$ quantum well structures. As a responsible mechanism we suggest switching-on of the kinetic exchange for the conduction electrons with finite $\mathbf{k}$ vectors. Quantitative agreement between experimental data and calculations is achieved.

A theory of Raman scattering of light by acoustic phonons in spherical nanocrystals of zinc-blende and wurtzite semiconductors has been developed with the inclusion of the complex structure of the valence band. The deformation-potential approximation was used to describe the exciton-phonon interaction. It is shown that this approximation allows only Raman scattering processes involving spheroidal acoustic phonons with a total angular momentum F=0 or 2. The effect of phonon quantum confinement on linewidth in Raman scattering spectra and scattered polarization is analyzed. An expression for the shape of the spectral line corresponding to nonresonant scattering from F=0 phonons was obtained.

Effective mass calculation of the acceptor ground state g-factor is presented for two limiting cases: infinite and zero spin–orbit coupling. Simple analytical expressions for the g-values are obtained within the framework of the zero-radius potential model. These results are in good agreement with experimental data for GaAs. Analytical expressions for the tensor g-factor are presented for strained wide-bandgap semiconductors with weak spin–orbit interaction (such as GaN). These results can be used for qualitative analysis of ODMR and ESR experimental data.

We report on optical studies of exciton magnetic polarons in artificial crystals of digital alloys of diluted magnetic (semimagnetic) semiconductors built of alternating CdTe and ${\mathrm{Cd}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{Te}$ layers, each only a few monolayers thick. Specially designed quantum well structures with the digital magnetic alloy in the quantum well region were grown and studied experimentally by magneto-optical methods. Precise comparative studies of the structures grown simultaneously either on (120)- or (100)-oriented substrates were performed by photoluminescence excitation spectroscopy and photoluminescence under selective excitation. While no difference in magnetic properties, as measured by the giant Zeeman splitting of excitonic states, was observed between (120)- and (100)-oriented diluted magnetic structures, the exciton magnetic polaron energy was found to be by $10--40%$ larger in (120)-oriented structures than in (100)-oriented counterparts. This increase is explained by the effect of the heavy-hole effective mass anisotropy: greater hole mass in [120] direction causes an enhancement of an initial exciton localization which, in turn, gives rise to an increase of the magnetic polaron energy. Results of model calculations are in good agreement with experimental data.

Spin-orbit splitting, strain-potential constants, and the g factor of the acceptor-center ground state described by a superposition of a Coulomb and a central-cell potential have been calculated for wide-band-gap semiconductors, such as GaN. Analytical expressions for these parameters, which depend only on the light-to heavy-hole mass ratio, have been obtained within the zero-range potential model. It is shown that the differences between these parameters for the limiting cases of purely Coulomb and zero-range potentials do not exceed 7%, thus permitting one to use for estimates simple analytical expressions. Calculation of the acceptor-center ground state made for the hexagonal modification of GaN suggests a strong anisotropy of the g factor, whereas measurements yield a practically isotropic value of g close to that of a free electron. This contradiction is removed if a spontaneous strain due to the Jahn-Teller effect appears perpendicular to the C6 axis of the crystal near the acceptor center.

An experimental and theoretical study of the magnetic polaron states of two-dimensional excitons in quantum wells based on semimagnetic semiconductors (Cd,Mn)Te is reported. It is shown that magnetic-polaron formation in in-plane magnetic fields leads to a lowering of the system symmetry, provided the fields are not too strong. The magnetic moment of the polaron thus formed is not parallel to the external magnetic field and contains a component normal to the quantum-well plane. This spontaneous lowering of the symmetry results in a change of the polarization characteristics of the luminescence from magnetic polaron states and in a weakening (compared to the three-dimensional case) in the efficiency of magnetic field-induced polaron suppression.

The importance of fluorescent detection in many fields is well established. While advancements in instrumentation and the development of brighter fluorophore have increased sensitivity and lowered the detection limits of the method, additional gains can be made by manipulating the local electromagnetic field. Herein we take advantage of silicon nanopillars that exhibit optical resonances and field enhancement on their surfaces and demonstrate their potential in improving performance of biomolecular fluorescent assays. We use electron beam lithography and wafer scale processes to create silicon nanoscale pillars with dimensions that can be tuned to maximize fluorescence enhancement in a particular spectral region. Performance of the nanopillar based fluorescent assay was quantified using two model bioaffinity systems (biotin-streptavidin and immunoglobulin G-antibody) as well as covalent binding of fluorescently tagged bovine serum albumin (BSA). The effects of pillar geometry and number of pillars in arrays were evaluated. Color specific and pillar diameter dependent enhancement of fluorescent signals is clearly demonstrated using green and red labels (FITC, DyLight 488, Alexa 568, and Alexa 596). The ratios of the on pillar to off pillar signals normalized by the nominal increase in surface area due to nanopillars were found to be 43, 75, and 292 for the IgG-antibody assay, streptavidin-biotin system, and covalently attached BSA, respectively. Applicability of the presented approaches to the detection of small numbers of molecules was evaluated using highly diluted labeled proteins and also control experiments without biospecific analytes. Our analysis indicates that detection of fewer than 10 tagged proteins is possible.

A method for the determination of magnetic polaron parameters is suggested for diluted magnetic semiconductors with low manganese concentration x, when the magnetic polaron shift of the exciton energy cannot be observed in practice. We show that the average exchange field, created by the localized exciton, and the magnetic polaron energy can be determined from the experimentally measured magnetic-field dependences of the circular polarization of the luminescence and Zeeman splitting of the free exciton. Theoretical dependences of the circular polarization on the magnetic field have been calculated in the two-dimensional case for different temperatures. Results of the calculations are in good agreement with our experimental data for CdTe/Cd12xMnxTe quantum wells with x50.117 and 0.13. @S0163-1829~96!06731-8# In semimagnetic semiconductors the strong exchange interaction between the charge carriers and electrons in the deep magnetic shell of magnetic ions manifests itself in the giant Zeeman splitting of the valence- and conduction-band states, the large Faraday rotation, and the formation of magnetic polarons ~MP’s !. 1,2 The magnetic polaron represents a small region in the crystal with strongly correlated spins of magnetic ions and carriers localized in this region. This spin ordering results in a decrease of the carrier energy, which is usually detected in optical experiments as a Stokes shift between the maximum of the photoluminescence line and the maximum of the photoluminescence excitation spectrum. 3‐5 Magnetic polaron states of localized excitons have been studied in the semimagnetic semiconductors Cd12xMnxTe with considerable magnetic-ion concentrations ~x>0.2!. 6,7 Three-dimensional polaron dynamics have been studied

In a strongly anisotropic quantum well structure containing semimagnetic quantum wells of Cd 098 M 0.02 Te and nonmagnetic barriers of Cd 0.76 Mg 0.24 Te a large number of paramagnetic resonance Raman lines can be observed in Voigt-geometry due to collective multiple spin flips within the Zeeman split Mn 2+ ground state, especially close to resonance with the heavy hole dipole transitions of the narrowest quantum well. This effect exhibits interesting temperature dependent polarization properties. The polarization is also influenced by small Faraday-components of the external magnetic field. The experiments can be explained by a precession of the total spin of all Mn 2+ ions within the localization volume of a localized exciton in the sum of extemal and exchange field (B ext ⊥B exch ), B exch produced by the heavy hole. The polarization properties are interpreted by a random distribution of Faraday-components of B ext due to undulations of the quantum well.

Circular polarized photoluminescence induced by magnetic fields in the Faraday geometry has been studied in CdTe Cd 1−x Mn x Te superlattices. An inversion of the sign of the magnetic hysteresis has been observed under excitation by nonpolarized light in the presence of magnetic fields. This effect is due to a nonequilibrium magnetization of Mn-ions induced by the spin orientation of photocarriers on Zeeman sublevels and is explained in terms of the dynamic polarization via a specific Overhauser process. This nonequilibrium magnetization has a long relaxation time of about 103 s at temperatures of 1.6 K caused by the slow thermo-activated spin relaxation of antiferromagnetic clusters of Mn-ions located in the barrier layers.

We observed up to 15 paramagnetic resonance Raman lines due to collective multiple spin flips within the Zeeman split ${\mathrm{Mn}}^{2+}$ ground state ${}^{6}{S}_{5/2}$ in a quantum well structure with semimagnetic ${\mathrm{Cd}}_{0.98}{\mathrm{Mn}}_{0.02}\mathrm{Te}$ wells and nonmagnetic ${\mathrm{Cd}}_{0.76}{\mathrm{Mn}}_{0.24}\mathrm{Te}$ barriers with external magnetic fields ${B}_{\mathrm{ext}}\ensuremath{\le}7.5$ T. This effect appears near resonance with the heavy-hole transitions of narrow quantum wells in the Voigt backscattering geometry and can be explained by a precession of the total spin of all ${\mathrm{Mn}}^{2+}$ ions in the sum of external and exchange field ( ${\stackrel{\ensuremath{\rightarrow}}{B}}_{\mathrm{ext}}\ensuremath{\perp}{\stackrel{\ensuremath{\rightarrow}}{B}}_{\mathrm{exch}}$), the latter produced by the heavy hole.

The analysis was applied to the indicators of hemostasis system under application of new anticoagulant, dabigatran etexilat, after hip joint arthroplasty. It is established that among the coagulation methods analysis the most specific to the effect of dabigatran is the testing of thrombin and echitox time of coagulation. Considering low sensitivity of the echitox to anticoagulation effect of D-dimer the echitox test is optimal for laboratory monitoring of application of dabigatran after orthopedic intervention.

Circular polarized photoluminescence induced by magnetic fields in Faraday geometry has been used for the study of spin relaxation processes in CdTe/Cd 1− x Mn x Te short-period superlattices. The spin relaxation has been found to be effective for the free carriers with kinetic energy and to be suppressed for carriers localized at fluctuations of magnetization. The effect of the inversion of sign of the magnetic hysteresis has been observed under excitation by nonpolarized light in the presence of magnetic field. The effect is due to a nonequilibrium magnetization of the Mn-ions which is induced by spin orientation of carriers on Zeeman sublevels in magnetic fields. This magnetization has a long relaxation time of about 10 3 s at temperatures of 1.6 K caused by the “frozen” magnetic moments of spin-glass clusters situated in barrier layers.

The purpose of the study was to choose an optimal anesthetic method to ensure adequate cerebral blood flow and to reduce the number of perioperative complications during carotid endarterectomy. Total intravenous anesthesia with diprivan, combined cervical plexus block anesthesia, and inhaled sevoflurane anesthesia were assessed in 190 patients undergoing carotid endarterectomy. The study of cerebral blood flow and central hemodynamic parameters indicated that deprivan anesthesia suppressed the major hemodynamic parameters, causing associated cerebral circulation depression. The use of cervical plexus block as a major component of anesthesia after Pashchuk stabilized the mean blood pressure and cardiac index, causing the optimization of cerebral blood flow parameters with a considerable postload increase. During sevoflurane anesthesia, the most physiological conditions for the performance of the circulatory system were found at all stages of surgical treatment, which predetermined the stable parameters of central hemodynamics and cerebral blood flow. The studies revealed that deprivan anesthesia was followed by a considerable number of both cardiac and neurological complications. The patients with cervical plexus block had fewer neurological disorders, but the increased postload accompanying these changes caused an increase in the number of cardiac complications. The most optimal parameters of cerebral blood flow and central hemodynamics during sevoflurane anesthesia induced a statistically significant reduction in the number of cardiac and neurological complications.

A very general theoretical discussion of the values of sp − d exchange constants is given starting from symmetry properties of diluted magnetic semiconductors. Complex structure of the valence band is fully taken into account with interacting heavy and light holes as well as spin–orbit split-off states kept in the consideration. The form of the Hamiltonian is derived and shown to be, in a general case, anisotropic. A series of approximations is made that reduces the Hamiltionian to a simple form introduced in Chap. 1. Specific cases of two-dimensional quantum wells and zero-dimensional spherical quantum dots are considered. Finally, the role of sp − d interaction in spin relaxation processes is discussed.

Spin dynamics of free carriers and dynamics of the magnetization in diluted magnetic semiconductors are coupled to each other and mostly determined by the spin and energy transfer between the carriers, magnetic ions, and lattice. The efficiency of this transfer is examined here for low-dimensional heterostructures fabricated from II–VI semiconductor-based DMSs containing Mn2 + . We show here that the dynamics depends strongly on Mn content as well as on specific design of those structures. Therefore, it can be controlled by optical and electrical means.

We observed simultaneously two types of Raman spectra in a GaAs/AlGaAs superlattice under high magnetic field: a folded longitudinal acoustic phonon, IFA, and a structureless background, IB. The temperature dependence of the intensities in both spectra was studied in the range 2–100K and it was established that the background spectrum is due to the first-order Raman scattering from acoustic phonons with a wide range of wave vectors. We obtained the expression for the intensities ratio IB/IFA. It depends on the relationship between the homogeneous and the inhomogeneous broadening of the intermediate state of the photoexcited e-h pair. A rapid decrease of IB observed at T 30K is thought to be due to the increase of the homogeneous width with temperature.

Spin systems with a long-range sign-alternating interaction undergoing a fluctuation phase transition are investigated. A new approach to the calculation of corresponding thermodynamic quantities is suggested. It is based on the summation of the principal part of high-temperature series in z-1 performed in a way which leads to a correct description of the critical behavior in the one-loop approxiamtion (z is the number of the neighbor spins interacting with a given one). The accuracy of the method is of a universal nature; for three-dimensional spin systems the error of some particular calculations is below 2%.

Optical pumping of electron spins and negative photoluminescence polarization are observed when interface quantum dots in a GaAs quantum well are excited nonresonantly by circularly polarized light. Both observations can be explained by the formation of long-lived dark excitons through hole spin relaxation in the GaAs quantum well prior to exciton capture. In this model, optical pumping of resident electron spins is caused by capture of dark excitons and recombination in charged quantum dots. Negative polarization results from accumulation of dark excitons in the quantum well and is enhanced by optical pumping. The dark exciton model describes the experimental results very well, including intensity and bias dependence of the photoluminescence polarization and the Hanle effect.