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The finite element model updating method of dynamical systems based on results of modal tests is proposed. The purpose of updating is to change eigenspectrum. The method alters a stiffness matrix by adding an updating finite element model created on the nodes of the intial one with respect to the existing links between the linear degrees of freedom. The stiffnesses of the updating elements are utilized as the updating parameters to be defined. The objective function equals to the least square weighted sum of residuals between the target, which were determined experimentally, and current values of modal stiffnesses. The iterative solution process is carried out. At each iteration step the conjugate gradient method is applied to solve the unconstrained minimization problem. The modeshapes, which were calculated as the result of solving the generalized eigenvalue problem at the previous iteration step, are employed to calculate the current modal stiffnesses. The method does not have a limit to a size of matrices and keeps their sparsity and symmetry. It provides the model updating of selected regions of a structure and step-by-step model updating of predefined groups of eigenfrequencies. Moreover, geometrical features of a structure, such as the presence of the symmetry planes and structurally identical elements, may be taken into account. The method is implemented into a program and verified by the example of the free dynamically-scaled model of Tu-204. In order to perform the ground vibration testing, the model was suspended with a low-rigidity flexible support. The finite element model made of solid elements has been updated on the basis of the six experimentally determined sets of eigenfrequencies. The target frequencies from each set have been achieved with a high level of accuracy.

A common feature of neurodegenerative disorders, in particular Alzheimer's disease (AD), is a chronic neuroinflammation associated with aberrant neuroplasticity. Development of neuroinflammation affects efficacy of stem and progenitor cells proliferation, differentiation, migration, and integration of newborn cells into neural circuitry. However, precise mechanisms of neurogenesis alterations in neuroinflammation are not clear yet. It is well established that expression of NLRP3 inflammasomes in glial cells marks neuroinflammatory events, but less is known about contribution of NLRP3 to deregulation of neurogenesis within neurogenic niches and whether neural stem cells (NSCs), neural progenitor cells (NPCs) or immature neuroblasts may express inflammasomes in (patho)physiological conditions. Thus, we studied alterations of neurogenesis in rats with the AD model (intra-hippocampal injection of Aβ1-42). We found that in Aβ-affected brain, number of CD133+ cells was elevated after spatial training in the Morris water maze. The number of PSA-NCAM+ neuroblasts diminished by Aβ injection was completely restored by subsequent spatial learning. Spatial training leads to elevated expression of NLRP3 inflammasomes in the SGZ (subgranular zones): CD133+ and PSA-NCAM+ cells started to express NLRP3 in sham-operated, but not AD rats. Taken together, our data suggest that expression of NLRP3 inflammasomes in CD133+ and PSA-NCAM+ cells may contribute to stimulation of adult neurogenesis in physiological conditions, whereas Alzheimer's type neurodegeneration abolishes stimuli-induced overexpression of NLRP3 within the SGZ neurogenic niche.

We present here the results obtained during the development of a portable device for rapid assessment of the functional state of the homeostasis system based on analysis of capillary blood. Vascular-thrombocytic hemostasis was assessed in volunteers in real time using the device. The results of piezocoagulography conducted using the portable device were compared to the results obtained by low-frequency piezothromboelastography (Mednord ARP-01M). These data showed a strong correlation, evidencing the potential of the method and device developed here for studies of the functional state of the hemostasis system at the patient’s bedside or outside hospital.

The Landé or g-factors of charge carriers are decisive for the spin-dependent phenomena in solids and provide also information about the underlying electronic band structure. We present a comprehensive set of experimental data for values and anisotropies of the electron and hole Landé factors in hybrid organic-inorganic (MAPbI3, MAPb(Br0.5Cl0.5)3, MAPb(Br0.05Cl0.95)3, FAPbBr3, FA0.9Cs0.1PbI2.8Br0.2, MA=methylammonium and FA=formamidinium) and all-inorganic (CsPbBr3) lead halide perovskites, determined by pump-probe Kerr rotation and spin-flip Raman scattering in magnetic fields up to 10 T at cryogenic temperatures. Further, we use first-principles density functional theory (DFT) calculations in combination with tight-binding and k ⋅ p approaches to calculate microscopically the Landé factors. The results demonstrate their universal dependence on the band gap energy across the different perovskite material classes, which can be summarized in a universal semi-phenomenological expression, in good agreement with experiment., Nature Communications;13

The outstanding optical quality of lead halide perovskites inspires studies of their potential for the optical control of carrier spins as pursued in other materials. Entering largely uncharted territory, time-resolved pump-probe Kerr rotation is used to explore the coherent spin dynamics of electrons and holes in bulk formamidinium caesium lead iodine bromide (FA0.9 Cs0.1 PbI2.8 Br0.2 ) and to determine key parameters characterizing interactions of their spins, such as the g-factors and relaxation times. The demonstrated long spin dynamics and narrow g-factor distribution prove the perovskites as promising competitors for conventional semiconductors in spintronics. The dynamic nuclear polarization via spin-oriented holes is realized and the identification of the lead (207 Pb) isotope in optically detected nuclear magnetic resonance proves that the hole-nuclei interaction is dominated by the lead ions. A detailed theoretical analysis accounting for the specifics of the lead halide perovskite materials allows the evaluation of the underlying hyperfine interaction constants, both for electrons and holes. Recombination and spin dynamics evidence that at low temperatures, photogenerated electrons and holes are localized at different regions of the perovskite crystal, resulting in their long lifetimes up to 44 μs. The findings form the base for the tailored development of spin-optoelectronic applications for the large family of lead halide perovskites and their nanostructures.

Aim. The presented study aims to examine, analyze, and systematize scientific knowledge in the field of infrastructure systems for the formation of conditions for creating competitive modern enterprises based on IT technologies.Tasks. The authors define the concept of innovation infrastructure; analyze the external and internal environment of providing a competitive infrastructure for business structures; determine the specific aspects of the formation of theoretical foundations of infrastructure support for the competitiveness of business structures; examine the potential for the digitalization of the economy in the infrastructure support for the creation of competitiveness of business structures.Methods. This study uses general scientific methods of cognition to critically analyze modern mechanisms of infrastructure support for the competitive advantages of innovation-oriented business structures.Results. External institutions participating in the innovation process in Russia are examined and typified. Their specific features are identified, and the history of their formation and role in the infrastructure are described. The concept of infrastructure support is examined. A correlation between innovation infrastructure and the creation of the competitive advantages of business structures is established.Conclusions. Based on the examined materials, the authors describe the prospects of using modern information technologies in the design of infrastructure for innovative projects. The study provides recommendations for the transformation of competitiveness support institutions and modernization of the management of the internal elements of innovative business infrastructure in the context of the digitalization of the economy. The authors create prerequisites for the development of an advanced digital application that would combine and balance a lot of data and aspects of infrastructure support for the competitiveness of business structures, improving the efficiency of development of innovative projects, their implementation, and management of business structure competitiveness.

Voltage control of ferromagnetism on the nanometer scale is highly appealing for the development of novel electronic devices with low power consumption, high operation speed, reliable reversibility and compatibility with semiconductor technology. Hybrid structures based on the assembly of ferromagnetic and semiconducting building blocks are expected to show magnetic order as a ferromagnet and to be electrically tunable as a semiconductor. Here, we demonstrate the electrical control of the exchange coupling in a hybrid consisting of a ferromagnetic Co layer and a semiconductor CdTe quantum well, separated by a thin non-magnetic (Cd,Mg)Te barrier. The electric field controls the phononic ac Stark effect—the indirect exchange mechanism that is mediated by elliptically polarized phonons emitted from the ferromagnet. The effective magnetic field of the exchange interaction reaches up to 2.5 Tesla and can be turned on and off by application of 1V bias across the heterostructure., Manipulating magnetic orders by electric fields promises energy efficient spintronic applications. Here the authors demonstrate electrical control of s-p exchange interaction in a ferromagnet-semiconductor quantum well structure due to the phononic ac Stark effect.

We demonstrate the realization of the resonant spin amplification (RSA) effect in Faraday geometry where a magnetic field is applied parallel to the optically induced spin polarization so that no RSA is expected. However, model considerations predict that it can be realized for a central spin interacting with a fluctuating spin environment. As a demonstrator, we choose an ensemble of singly-charged (In,Ga)As/GaAs quantum dots, where the resident electron spins interact with the surrounding nuclear spins. The observation of RSA in Faraday geometry requires intense pump pulses with a high repetition rate and can be enhanced by means of the spin-inertia effect. Potentially, it provides the most direct and reliable tool to measure the longitudinal $g$ factor of the charge carriers., 7 pages including 4 figures; 8 pages supplement including 4 figures

The effective $g$ factor of holes is measured in modulation-doped ZnSe/(Zn,Mg)(S,Se) quantum wells and from surface-state $p$-doped CdTe/(Cd,Mg)Te quantum wells by time-resolved pump-probe Kerr rotation. The measurements are performed at a temperature of 1.7 K and in magnetic fields up to 5 T applied in the Voigt geometry with orientation perpendicular to the quantum-well growth axis. The absolute value of the in-plane hole $g$ factor increases with growing magnetic field in both studied heterostructures. A theoretical model is developed that considers the influence of magnetic field and interface mixing of heavy-hole and light-hole states on the $g$ factor. The model results are in good agreement with the experimental data.

In this paper, we discuss an application of the method of the Digital Laser Speckle Image Correlation method (DIC) for studying the aggregation function of platelets in whole blood with the maximum standardization of the pre-analytical and analytical stages of the study. Materials and images are provided, methods are explained.

The recombination dynamics and spin polarization of excitons in CdSe nanocrystals synthesized in a glass matrix are investigated using polarized photoluminescence in high magnetic fields up to 30 Tesla. The dynamics are accelerated by increasing temperature and magnetic field, confirming the dark exciton nature of low-temperature photoluminescence (PL). The circularly polarized PL in magnetic fields reveals several unusual appearances: (i) a spectral dependence of the polarization degree, (ii) its low saturation value, and (iii) a stronger intensity of the Zeeman component which is higher in energy. The latter feature is the most surprising being in contradiction with the thermal population of the exciton spin sublevels. The same contradiction was previously observed in the ensemble of wet-chemically synthesized CdSe nanocrystals but was not understood. We present a theory which explains all the observed features and shows that the inverted ordering of the circularly polarized PL maxima from the ensemble of nanocrystals is a result of competition between the zero phonon (ZPL) and one optical phonon-assisted (1PL) emission of the dark excitons. The essential aspects of the theoretical model are different polarization properties of the dark exciton emission via ZPL and 1PL recombination channels and the inhomogeneous broadening of the PL spectrum from the ensemble of nanocrystals exceeding the optical phonon energy.

We report on theoretical and experimental study of the spin polarization recovery and Hanle effect for the charge carriers interacting with the fluctuating nuclear spins in the semiconductor structures. We start the theoretical description from the simplest model of static and isotropic nuclear spin fluctuations. Then we describe the modification of the polarization recovery and Hanle curves due to the anisotropy of the hyperfine interaction, finite nuclear spin correlation time, and the strong pulsed spin excitation. For the latter case, we describe the resonance spin amplification effect in the Faraday geometry and discuss the manifestations of the quantum Zeno effect. The set of the experimental results for various structures and experimental conditions is chosen to highlight the specific effects predicted theoretically. We show that the spin polarization recovery is a very valuable tool for addressing carrier spin dynamics in semiconductors and their nanostructures., Comment: 16 pages, 15 figures

The effective electron $g$ factor, ${g}_{\text{eff}}$, is measured in a two-dimensional electron gas (2DEG) in modulation-doped ZnSe- and CdTe-based quantum wells by means of time-resolved pump-probe Kerr rotation. The measurements are performed in magnetic fields applied in the Voigt geometry, i.e., normal to the optical axis parallel to the quantum well plane, in the field range $0.05--6$ T at temperatures $1.8--50\phantom{\rule{0.28em}{0ex}}\mathrm{K}$. The ${g}_{\text{eff}}$ absolute value considerably increases with increasing electron density ${n}_{e}$. ${g}_{\text{eff}}$ changes in the ZnSe-based QWs from $+1.1$ to $+1.9$ in the ${n}_{e}$ range $3\ifmmode\times\else\texttimes\fi{}{10}^{10}\ensuremath{-}1.4\ifmmode\times\else\texttimes\fi{}{10}^{12}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$ and in the CdTe-based QWs from $\ensuremath{-}1.55$ down to $\ensuremath{-}1.76$ in the ${n}_{e}$ range $5\ifmmode\times\else\texttimes\fi{}{10}^{9}\ensuremath{-}3\ifmmode\times\else\texttimes\fi{}{10}^{11}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$. The modification of ${g}_{\text{eff}}$ reduces with increasing magnetic field, increasing temperature of lattice and 2DEG, the latter achieved by a higher photoexcitation density. A theoretical model is developed that considers the renormalization of the spin-orbit coupling constant of the two-dimensional electrons by the electron-electron interaction and takes into account corrections to the electron-electron interaction in the Hubbard form. The model results are in good agreement with experimental data.

A common feature of neurodegenerative disorders, in particular Alzheimer's disease (AD), is a chronic neuroinflammation associated with aberrant neuroplasticity. Development of neuroinflammation affects efficacy of stem and progenitor cells proliferation, differentiation, migration, and integration of newborn cells into neural circuitry. However, precise mechanisms of neurogenesis alterations in neuroinflammation are not clear yet. It is well established that expression of NLRP3 inflammasomes in glial cells marks neuroinflammatory events, but less is known about contribution of NLRP3 to deregulation of neurogenesis within neurogenic niches and whether neural stem cells (NSCs), neural progenitor cells (NPCs) or immature neuroblasts may express inflammasomes in (patho)physiological conditions. Thus, we studied alterations of neurogenesis in rats with the AD model (intra-hippocampal injection of Aβ1-42). We found that in Aβ-affected brain, number of CD133+ cells was elevated after spatial training in the Morris water maze. The number of PSA-NCAM+ neuroblasts diminished by Aβ injection was completely restored by subsequent spatial learning. Spatial training leads to elevated expression of NLRP3 inflammasomes in the SGZ (subgranular zones): CD133+ and PSA-NCAM+ cells started to express NLRP3 in sham-operated, but not AD rats. Taken together, our data suggest that expression of NLRP3 inflammasomes in CD133+ and PSA-NCAM+ cells may contribute to stimulation of adult neurogenesis in physiological conditions, whereas Alzheimer's type neurodegeneration abolishes stimuli-induced overexpression of NLRP3 within the SGZ neurogenic niche.

The effect of a lateral electric current on the photoluminescence H band of an AlGaAs/GaAs heterostructure is investigated. The photoluminescence intensity and optical orientation of electrons contributing to the H band are studied by means of continuous-wave and time-resolved photoluminescence spectroscopy and time-resolved Kerr rotation. It is shown that the H band is due to recombination of the heavy holes localized at the heterointerface with photoexcited electrons attracted to the heterointerface from the GaAs layer. Two lines with significantly different decay times constitute the H band: a short-lived high-energy one and a long-lived low-energy one. The high-energy line originates from recombination of electrons freely moving along the structure plane, while the low-energy one is due to recombination of donor-bound electrons near the interface. Application of a lateral electric field of \ensuremath{\sim}100--200 V/cm results in a quenching of both lines. This quenching is due to a decrease of electron concentration near the heterointerface as a result of a photocurrent-induced heating of electrons in the GaAs layer. On the contrary, electrons near the heterointerface are effectively cooled, so the donors near the interface are not completely empty up to \ensuremath{\sim}100 V/cm, which is in stark contrast with the case of bulk materials. The optical spin polarization of the donor-bound electrons near the heterointerface weakly depends on the electric field. Their polarization kinetics is determined by the spin dephasing in the hyperfine fields of the lattice nuclei. The long spin memory time (g40 ns) can be associated with suppression of the Bir-Aronov-Pikus mechanism of spin relaxation for electrons.

The coherent spin dynamics of electrons in tunnel-coupled CdTe and (Cd,Mn)Te quantum wells (QWs) is studied by time-resolved pump-probe Kerr rotation. The coupled QWs have different thicknesses; the narrow one is doped by ${\mathrm{Mn}}^{2+}$ magnetic ions. A short range proximity effect between them is observed: the Zeeman splitting of electrons in the wide QW is given in addition to the intrinsic electron $g$ factor by the exchange interaction with the ${\mathrm{Mn}}^{2+}$ ions mediated by electron tunneling into the narrow QW. The exchange interaction strength scales with the ${\mathrm{Cd}}_{0.88}{\mathrm{Mg}}_{0.12}\mathrm{Te}$ barrier thickness separating the QWs. The Kerr rotation signal measured on the wide QW shows two close frequencies of electron spin Larmor precession in a transverse magnetic field. These components have very different spin dephasing times, 50 ps and 1 ns. The two frequencies originate from electrons in the wide QW being either part of an exciton or being resident. The proximity effect of the exciton electron is smaller due to the binding by Coulomb interaction, which decreases the tunneling to the narrow well. The experimental data are in good agreement with model calculations.

Pathologies associated with perinatal exposure of the CNS to damaging factors, including hypoxia, are a serious problem. However, the mechanisms by which they influence the development of brain damage have been insufficiently studied. The purpose of this study is to analyze the BBB permeability and expression of markers of its structural and functional integrity in animals with hypoxia (rats subjected to hypoxia at the age of P7) at the early (1 hour after the hypoxia) and delayed (P28) periods of their development. In sections of the rat brains, we immunohistochemically evaluated the expression of HIF-1 and Rac1; the Evans blue dye content was measured by the photometric method in the brain homogenates. In animals subjected to hypoxia, BBB permeability increased, CD31 expression was reduced, RAC1 expression increased, HIF-1-positive cells were retained in the hippocampus mainly at the early stage of development; CD31 and RAC1 expression was suppressed during the delayed period of development. The most-pronounced brain damage at the age of P7 corresponds to changes in the structural and functional integrity and permeability of the BBB; the recovery of a neurological deficit and the permeability of the BBB (at the age of P28) under damage to the brain corresponds to the period of reparative angiogenesis, as well as manifestations of HIF-1 effects in endothelial cells and astrocytes in the cortex and limbic system.

The work presents the experimental results of the dynamics of the domain wall in the plate of yttrium orthoferrite. In our case the speeds of this motion are much less than the speeds of sound in these crystals. A constant magnetic field was oriented parallel to the plate along the domain wall motion and at the angle ≈ 50° to the sample plane and parallel to the plate along the DW motion. We consider forced vibrations of the domain wall under the influence of weak alternating magnetic fields. The domain walls motion was caused by an alternating magnetic field, which was generated by the coils. The effect of the constant magnetic field on the domain wall dynamics has been found.

The expression of thrombospondin-1 (TS-1) and its receptors CD47 and CD36 in the cerebral cortex and hippocampus of rats under damaging factors in the early postnatal period was studied. After hypoxia on the 7th day of postnatal development, an increase in the number of CD47-expressing cerebral endothelial cells (days of postnatal development: P28–P70) and reduction in the number of TS-1-expressing astrocytes in the cortex at P28 were observed. In animals subjected to early postnatal stress at the age of P2–P15, a decrease in TS-1-expressing astrocytes in the cortex and hippocampus was registered (predominantly at the age of P28). It was noted that these changes characterize the period of long-term effects (P28–P70) of early stress that is relevant to the processes of reparative angiogenesis and arresting of neurological deficits.

Spin-dependent photon echoes in combination with pump-probe Kerr rotation are used to study the microscopic electron spin transport in a CdTe/(Cd,Mg)Te quantum well in the hopping regime. We demonstrate that independent of the particular spin relaxation mechanism, hopping of resident electrons leads to a shortening of the photon echo decay time, while the transverse spin relaxation time evaluated from pump-probe transients increases due to motional narrowing of spin dynamics in the fluctuating effective magnetic field of the lattice nuclei., 11 pages, 8 figures

Modal testing is an efficient tool for checking and updating of computational dynamic models of aircraft. Test objects are fixed by special elastic suspension systems during the modal testing time. Stiffness characteristics of such systems are determined on the assumption that the impact of the suspension on the eigentones of elastic vibrations of a freely flying aircraft should not exceed the pre-arranged level. It is therefore considered that the vibration frequency of the structure as a rigid body on the suspension should be several times lower than the natural frequency of the first flexible mode. Besides, different sources recommend various ratios between these frequencies. As to the modal testing of large flexible space structures, the task of creating such a suspension becomes many times more difficult because such structures can have very low natural frequencies of flexible modes. The influence of the suspension system on the accuracy of the aircraft modal testing results manifests itself in two ways. On the one hand, the use of the suspension leads to an increase of all natural frequencies of the test object. On the other hand, the occurrence of modes of the object as a rigid body with non-zero frequencies leads to the aircraft phase resonance frequency shifts which determine the natural frequencies of flexible mode tones. The paper presents a technique for correcting an aircraft computational dynamic model taking into account the suspension system. The correction is based on the fact that the errors in measurement of displacements in modal tests (i.e. eigenmodes as well) are greater than the errors in determining natural frequencies by more than an order of magnitude. The effect of modes of an object as a rigid body on an elastic suspension system on the accuracy of determination of its natural frequencies, generalized masses and generalized damping factors of flexible modes is analyzed.

We studied antitumor properties of modified detonation nanodiamonds loaded with doxorubicin on in vivo model of Ehrlich ascites carcinoma. The type of tumor development and morphological characteristics of the liver, kidneys, and spleen were evaluated in experimental animals. Modified nanodiamonds injected intraperitoneally produced no antitumor effect on Ehrlich carcinoma. However, doxorubicin did not lose antitumor activity after sorption on modified nanodiamonds.

Anisotropy of bulk acoustic wave propagation in rhombohedral crystal is investigated. The phase velocities for different acoustic modes were analytically calculated from the solution of the Christoffel Matrix eigenvalues problem for homogeneous media. Other related wave quantities such as group velocity, slowness vector and power flow angle were also obtained as functions of the elastic stiffness constants and the propagation or ray direction. The normal, slowness and ray surfaces reflect the anisotropy of elastic properties and allow one to obtain the directions of strictly transversal and longitudinal modes and acoustic axes. The resulting graphics were performed in polar coordinates using standard OriginPro plotting tools. All the calculations have been performed for a crystal of hematite but the method is applicable to analysis of elastic properties in different crystals.

The spin inertia measurement is a recently emerged tool to study slow spin dynamics, which is based on the excitation of the system by a train of circularly polarized pulses with alternating helicity. Motivated by the experimental results reported in E. A. Zhukov et al., arXiv:1806.11100 we develop the general theory of spin inertia of localized charge carriers. We demonstrate that the spin inertia measurement in longitudinal magnetic field allows one to determine the parameters of the spin dynamics of resident charge carriers and of photoexcited trions, such as the spin relaxation times, longitudinal g-factors, parameters of hyperfine interaction and nuclear spin correlation times., Comment: 11 pages, 7 figures. This is a joint submission with "Spin Inertia of Resident and Photoexcited Carriers in Singly-Charged Quantum Dots" by the same authors

The coherent spin dynamics of fluorine donor-bound electrons in ZnSe induced by pulsed optical excitation is studied in a perpendicular applied magnetic field. The Larmor precession frequency serves as a measure for the total magnetic field exerted onto the electron spins and, surprisingly, does not increase linearly with the applied field, but shows a step-like behavior with pronounced plateaus, given by multiples of the laser repetition rate. This discretization occurs by a feedback mechanism in which the electron spins polarize the nuclear spins, which in turn generate a local Overhauser field adjusting the total magnetic field accordingly. Varying the optical excitation power, we can control the plateaus, in agreement with our theoretical model. From this model, we trace the observed discretization to the optically induced Stark field, which causes the dynamic nuclear polarization., Understanding the electron and nuclear spin interactions is essential to the application of quantum information devices. Here the authors report a step-like electron Larmor frequency versus external magnetic field due to the discretization of the total magnetic field by the nuclear spin bath in ZnSe:F.

The spin dynamics in a broad range of systems can be studied using circularly polarized optical excitation with alternating helicity. The dependence of spin polarization on the frequency of helicity alternation, known as the spin inertia effect, is used here to study the spin dynamics in singly-charged (In,Ga)As/GaAs quantum dots (QDs) providing insight into spin generation and accumulation processes. We demonstrate that the dependence of spin polarization in $n$- and $p$-type QDs on the external magnetic field has a characteristic V- and M-like shape, respectively. This difference is related to different microscopic mechanisms of resident carriers spin orientation. It allows us to determine the parameters of the spin dynamics both for the ground and excited states of singly-charged QDs., Comment: 5 pages, 3 figures. This is a joint submission with "Theory of spin inertia in singly-charged quantum dots" by the same authors

The exchange interaction between magnetic ions and charge carriers in semiconductors is considered to be a prime tool for spin control. Here, we solve a long-standing problem by uniquely determining the magnitude of the long-range $p\ensuremath{-}d$ exchange interaction in a ferromagnet-semiconductor (FM-SC) hybrid structure where a 10-nm-thick CdTe quantum well is separated from the FM Co layer by a CdMgTe barrier with a thickness on the order of 10 nm. The exchange interaction is manifested by the spin splitting of acceptor bound holes in the effective magnetic field induced by the FM. The exchange splitting is directly evaluated using spin-flip Raman scattering by analyzing the dependence of the Stokes shift ${\mathrm{\ensuremath{\Delta}}}_{S}$ on the external magnetic field $B$. We show that in a strong magnetic field, ${\mathrm{\ensuremath{\Delta}}}_{S}$ is a linear function of $B$ with an offset of ${\mathrm{\ensuremath{\Delta}}}_{pd}=50--100\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}\mathrm{eV}$ at zero field from the FM induced effective exchange field. On the other hand, the $s\ensuremath{-}d$ exchange interaction between conduction band electrons and FM, as well as the $p\ensuremath{-}d$ contribution for free valence band holes, are negligible. The results are well described by the model of indirect exchange interaction between acceptor bound holes in the CdTe quantum well and the FM layer mediated by elliptically polarized phonons in the hybrid structure.

The kinetics of water vapor adsorption on the porous silicon surface is studied by the gas relaxometry method. The process multistepping which is reflected in sequential changes in H2O molecule diffusivities into the porous matrix, is found. Phenomenological models describing the experiment are considered.

Spin coherence of resident electrons and holes is measured in ZnSe-based quantum wells by means of time-resolved Kerr rotation technique. At a temperature of 1.8 K spin dephasing time for localized electrons can be as long as 33 ns, and for holes of 0.8 ns. Electron spin precession is clearly observed in a wide temperature range up to 230 K. The electron spin dephasing becomes much shorter of 0.2 ns for the quantum well with a high-density electron gas. Using vector magnet all components of the g-factors tensor are evaluated for the electrons and heavy-holes, revealing strong anisotropy for the heavy-holes.

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