In this paper,we investigate the optical properties of a non-rotating charged black hole(BH)in the Einstein-Maxwell-scalar(EMS)theory,together with a plasma medium.We first consider the photon sphere and shadow radius...In this paper,we investigate the optical properties of a non-rotating charged black hole(BH)in the Einstein-Maxwell-scalar(EMS)theory,together with a plasma medium.We first consider the photon sphere and shadow radius under the impact of the plasma medium existing in the environment surrounding the BH in the EMS theory.We show that the radius of the photon sphere and the BH shadow decrease under the influence of the parameterβ.We further study gravitational weak lensing in detail by adapting general methods and derive the light ray's deflection angle around the BH together with the plasma environment.It is found that for uniform plasma,the deflection angle increases with the rise of the plasma parameter,whereas it decreases with the increase of the plasma parameter for non-uniform plasma.Besides,we also study the magnification of image brightness.展开更多
The article is devoted to the economic and biological characteristics of promising desert semi-shrub halophytes (Kochia prostrate, Salsola orientalis, Ceratoides ewersmaniana, Halothamhus subaphyllus, Camphorosma less...The article is devoted to the economic and biological characteristics of promising desert semi-shrub halophytes (Kochia prostrate, Salsola orientalis, Ceratoides ewersmaniana, Halothamhus subaphyllus, Camphorosma lessingii) to improve saline lands of the Kyzylkum desert.展开更多
The article provides an analysis of the distribution of fourteen species belonging to seven sections of the genus Dracocephalum in the phytogeographical regions of Uzbekistan.
In this article, the lifetime data subjecting to right random censoring is considered. Nonparametric estimation of the distribution function based on the conception of presmoothed estimation of relative-risk function ...In this article, the lifetime data subjecting to right random censoring is considered. Nonparametric estimation of the distribution function based on the conception of presmoothed estimation of relative-risk function and the properties of the estimator by using methods of numerical modeling are discussed. In the model under consideration, the estimates were compared using numerical methods to determine which of the estimates is actually better.展开更多
The temperature dependence of the density of states in strong magnetic fields. On the basis of the model constructed, a computer program calculating the density of electronic states in a quantizing magnetic field. Use...The temperature dependence of the density of states in strong magnetic fields. On the basis of the model constructed, a computer program calculating the density of electronic states in a quantizing magnetic field. Used new, based on quantum statistics, the approach to the calculation of the temperature dependence of the density of states in a strong magnetic field. Mathematical modeling of the density of states using the experimental values of a continuous density of states makes it possible to calculate the Landau levels.展开更多
Nanoscale superlattice has been investigated theoretically. It has been shown that the deformation effects on the energy spectrum of nanoscale superlattice by changing the interatomic distances as well as varying the ...Nanoscale superlattice has been investigated theoretically. It has been shown that the deformation effects on the energy spectrum of nanoscale superlattice by changing the interatomic distances as well as varying the width and height of the potential barrier. The potential deformation has been estimated. It has been shown that for different edges of forbidden bands the deformation potential has different values. It has been also analyzed the dependence of the effective mass on energy. It has been determined that the effective mass crosses periodically the zero mark. It has been concluded that this phenomena contributes to the periodic change of the oscillation frequency de Haas-van Alphen effect.展开更多
The large life cycle Rhaponticum integrifolium in natural populations (Qashqadaryo, Uzbekistan) was studied. Duration of before generative, generative and senile periods of Rhaponticum integrifolium is 2 - 5, 8 - 10 a...The large life cycle Rhaponticum integrifolium in natural populations (Qashqadaryo, Uzbekistan) was studied. Duration of before generative, generative and senile periods of Rhaponticum integrifolium is 2 - 5, 8 - 10 and 2 - 4 years respectively. The beginning of phenophases depends on the height of the terrain above sea level: raising the terrain from 400 to 1500 m leads to a delay in the onset of phenophases. Age states of Rhaponticum integrifolium in different ecological and phytogenetic conditions were revealed. Updated distribution of detected participation of vegetation and the raw Rhaponticum integrifolium in Uzbekistan, describes the dynamics of the contents ecdysteroids in the periods of vegetation. At the same time, a map of the species area in Central Asia was made and the term of its phytomass recovery under different operating modes of thickets was determined.展开更多
In the present paper asymptotic solution of boundary-value problem of three-dimensional micropolar theory of elasticity with free fields of displacements and rotations is constructed in thin domain of the shell. This ...In the present paper asymptotic solution of boundary-value problem of three-dimensional micropolar theory of elasticity with free fields of displacements and rotations is constructed in thin domain of the shell. This boundary-value problem is singularly perturbed with small geometric parameter. Internal iteration process and boundary layers are constructed, problem of their jointing is studied and boundary conditions for each of them are obtained. On the basis of the results of the internal boundary-value problem the asymptotic two-dimensional model of micropolar elastic thin shells is constructed. Further, the qualitative aspects of the asymptotic solution are accepted as hypotheses and on the basis of them general applied theory of micropolar elastic thin shells is constructed. It is shown that both the constructed general applied theory of micropolar elastic thin shells and the classical theory of elastic thin shells with consideration of transverse shear deformations are asymptotically confirmed theories.展开更多
The sources about the seasonal and blossoming biology of some Ferula L. (F angrenii, F. ovina, F. dshizakensis, F. helenae) types which can be found in Western Pamir-Alay have been given in the article.
The article presents the features of biology and ecology, growth and development of various </span><i><span style="font-family:Verdana;">Lycium</span></i><span style="fo...The article presents the features of biology and ecology, growth and development of various </span><i><span style="font-family:Verdana;">Lycium</span></i><span style="font-family:Verdana;"> L</span></span><span style="font-family:Verdana;">.</span><span style="font-family:""><span style="font-family:Verdana;"> species in different ecological conditions of Uzbekistan. The distribution area covers mainly semi-desert and desert zones of Uzbekistan and the description of co-growing coenoses is presented. Based on the study of ecological and biological properties and economically valuable characteristics of </span><i><span style="font-family:Verdana;">Lycium</span></i><span style="font-family:Verdana;"> L</span></span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> species, ecologically significant species were selected as a source material for introduction into culture and use in pharmacology. Useful properties and harms are presented.展开更多
It is shown that the mean value of the capacitive current arising in the p-n-junction in a microwave field is zero, and the average value of the active current independently of the current value is different from zero...It is shown that the mean value of the capacitive current arising in the p-n-junction in a microwave field is zero, and the average value of the active current independently of the current value is different from zero and is equal to the current generated by the diode.展开更多
It is shown that the increase in the current of an asymmetric p-n-junction, caused by perturbation of potential barrier height and increasing recombination current in a strong microwave field, is suppressed by light g...It is shown that the increase in the current of an asymmetric p-n-junction, caused by perturbation of potential barrier height and increasing recombination current in a strong microwave field, is suppressed by light generated photo carriers, leading to the displacement of current-voltage characteristics of p-n-junction into the direction of smaller current values.展开更多
It is shown that the nonideality coefficient m actually depends on the electron temperature Te, and the hole temperature Th. We get more general expression for the nonideality coefficient, taking into account the conc...It is shown that the nonideality coefficient m actually depends on the electron temperature Te, and the hole temperature Th. We get more general expression for the nonideality coefficient, taking into account the concentration of electrons and holes, as well as their temperature, coefficient and diffusion length, the temperature of the phonons, the applied voltage, and the height of the potential barrier.展开更多
The riparian (tugai) forest ecosystems of Central Asia are a biodiversity hotspot with unique many trees and shrubs. Intense human pressure and global warming have caused habitat destruction in Zerafshan State Nationa...The riparian (tugai) forest ecosystems of Central Asia are a biodiversity hotspot with unique many trees and shrubs. Intense human pressure and global warming have caused habitat destruction in Zerafshan State National park and it’s 23.5 ha. There grow more than 300 higher plants. We analysed the wild flora and the remains of the species diversity that previously existed on the site of the forestry enterprise, the modern biodiversity of trees and shrubs in the described territory are represented by 52 species from among representatives of 21 plant families. These monitoring and results indicated that some tree species might in the near future become extinct in the wild. We therefore recommend that the local people be encouraged to stop using these trees.展开更多
Central Asia is one of the main centers of origin of bulbous geophytes, including the family Amaryllidaceae Juss. The anatomical features of many endemic, red-book bulbous geophytes are still poorly understood. The ar...Central Asia is one of the main centers of origin of bulbous geophytes, including the family Amaryllidaceae Juss. The anatomical features of many endemic, red-book bulbous geophytes are still poorly understood. The article presents the results of a structural study of the inflated part of the stem (fistular), stem and pedicels of an endemic A. praemixtum species grow in two different environmental conditions in the Aktau mountain Nurata Range (Uzbekistan, Province Navoi) and in the conditions of introduction in the Tashkent Botanical Garden (Uzbekistan, Tashkent city). Diagnostic signs of vegetative organs were revealed and various combinations of xeromorphic and mesomorphic signs were determined. Comparative anatomical study of vegetative organs of A. praemixtum is of great theoretical and practical importance in relation to taxonomy and ecology.展开更多
In this study,we examine the effects of weak gravitational lensing and determine the shadow radius around black holes within the Dyonic ModMax(DM)spacetime,also accounting for models with nonuniform plasma distributio...In this study,we examine the effects of weak gravitational lensing and determine the shadow radius around black holes within the Dyonic ModMax(DM)spacetime,also accounting for models with nonuniform plasma distributions.By analyzing various gravitational lens models,we compare corrections to vacuum lensing due to gravitational effects within plasma and plasma inhomogeneity,finding that these effects could be observed in hot gas within galaxy clusters.Starting with the orbits of photons around a black hole in DM,we investigate the shadow and weak gravitational lensing phenomena.Utilizing observational data from the Event Horizon Telescope for M87*and SgrA*,we constrain parameters within DM gravity.To connect our findings to observations,we examine the magnification and positioning of lensed images,along with the weak deflection angle and magnification for sources near different galaxies.展开更多
The article presents the results of studies of the anatomical structure of the vegetative organs of </span><i><span style="font-family:Verdana;">Allium </span><span style="fon...The article presents the results of studies of the anatomical structure of the vegetative organs of </span><i><span style="font-family:Verdana;">Allium </span><span style="font-family:Verdana;">kysylkumi</span></i><span style="font-family:Verdana;"> of the Amaryllidaceae family, which grows in the conditions of Kyzylkum (Kokchatau outlier mountain). The characteristic diagnostic features have been determined: the outer membrane of epidermal cells is well developed by the outer folded cuticle, cutinized and more thickened;leaves are amphistomatic;stomata are the most submerged, </span><span style="font-family:Verdana;">anomocytic</span><span style="font-family:Verdana;"> type;isolateral-palisade type of leaf mesophyll;the conducting bundles </span><span style="font-family:Verdana;">are closed, collateral and are arranged in two rows, of which the upper side is represented only by small bundles, in the lower row, 3 large bundles alternate with one small bundle;peduncle and peduncle, parenchymal-beam type of structure;the epidermis is single-row, fold</span><span style="font-family:Verdana;">ed cuticle with more thickened and cutinized;the crustal parenchyma is thin-walled, round-oval, chlorophyll-bearing;the presence of lactic acid is in the cow parenchyma;the primary cortex is separated from the central cylinder by a ring of sclerenchyma;the central cylinder is extensive;closed collateral-type conductive bundles.</span><b> </b><span style="font-family:Verdana;">In the vegetative organs of </span><i><span style="font-family:Verdana;">Allium </span><span style="font-family:Verdana;">kysylkumi</span></i><span style="font-family:Verdana;">, especially in the leaf, xeromorphic characters are pronounced, which indicates the fitness of this species in natural habitat. The revealed structural diagnostic signs of vegetative organs are </span><span style="font-family:Verdana;">species-specific,</span><span style="font-family:Verdana;"> and show the adaptation of this species to its natural habitat, these micromorphological signs are taxonomic significance for distinguishing and identifying </span><i><span style="font-family:Verdana;">Allium</span></i><span style="font-family:Verdana;"> species.展开更多
The study of the parameter space of chaotic systems is complicated by its high dimensionality (multi-parametricability). Two approaches to the study of chaotic systems are presented: multi-parameter analysis and optim...The study of the parameter space of chaotic systems is complicated by its high dimensionality (multi-parametricability). Two approaches to the study of chaotic systems are presented: multi-parameter analysis and optimal suppression of chaotic dynamics. For non-autonomous chaotic systems, this is the way to compare the effectiveness of various correction parameters that provide optimal removal of irregular dynamics. For the class of autonomous chaotic systems, this is the way to investigate the optimal conditions of super-stable behavior for the chaotic system.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.11675143the National Key Research and Development Program of China under Grant No.2020YFC2201503。
文摘In this paper,we investigate the optical properties of a non-rotating charged black hole(BH)in the Einstein-Maxwell-scalar(EMS)theory,together with a plasma medium.We first consider the photon sphere and shadow radius under the impact of the plasma medium existing in the environment surrounding the BH in the EMS theory.We show that the radius of the photon sphere and the BH shadow decrease under the influence of the parameterβ.We further study gravitational weak lensing in detail by adapting general methods and derive the light ray's deflection angle around the BH together with the plasma environment.It is found that for uniform plasma,the deflection angle increases with the rise of the plasma parameter,whereas it decreases with the increase of the plasma parameter for non-uniform plasma.Besides,we also study the magnification of image brightness.
文摘The article is devoted to the economic and biological characteristics of promising desert semi-shrub halophytes (Kochia prostrate, Salsola orientalis, Ceratoides ewersmaniana, Halothamhus subaphyllus, Camphorosma lessingii) to improve saline lands of the Kyzylkum desert.
文摘The article provides an analysis of the distribution of fourteen species belonging to seven sections of the genus Dracocephalum in the phytogeographical regions of Uzbekistan.
文摘In this article, the lifetime data subjecting to right random censoring is considered. Nonparametric estimation of the distribution function based on the conception of presmoothed estimation of relative-risk function and the properties of the estimator by using methods of numerical modeling are discussed. In the model under consideration, the estimates were compared using numerical methods to determine which of the estimates is actually better.
文摘The temperature dependence of the density of states in strong magnetic fields. On the basis of the model constructed, a computer program calculating the density of electronic states in a quantizing magnetic field. Used new, based on quantum statistics, the approach to the calculation of the temperature dependence of the density of states in a strong magnetic field. Mathematical modeling of the density of states using the experimental values of a continuous density of states makes it possible to calculate the Landau levels.
文摘Nanoscale superlattice has been investigated theoretically. It has been shown that the deformation effects on the energy spectrum of nanoscale superlattice by changing the interatomic distances as well as varying the width and height of the potential barrier. The potential deformation has been estimated. It has been shown that for different edges of forbidden bands the deformation potential has different values. It has been also analyzed the dependence of the effective mass on energy. It has been determined that the effective mass crosses periodically the zero mark. It has been concluded that this phenomena contributes to the periodic change of the oscillation frequency de Haas-van Alphen effect.
文摘The large life cycle Rhaponticum integrifolium in natural populations (Qashqadaryo, Uzbekistan) was studied. Duration of before generative, generative and senile periods of Rhaponticum integrifolium is 2 - 5, 8 - 10 and 2 - 4 years respectively. The beginning of phenophases depends on the height of the terrain above sea level: raising the terrain from 400 to 1500 m leads to a delay in the onset of phenophases. Age states of Rhaponticum integrifolium in different ecological and phytogenetic conditions were revealed. Updated distribution of detected participation of vegetation and the raw Rhaponticum integrifolium in Uzbekistan, describes the dynamics of the contents ecdysteroids in the periods of vegetation. At the same time, a map of the species area in Central Asia was made and the term of its phytomass recovery under different operating modes of thickets was determined.
文摘In the present paper asymptotic solution of boundary-value problem of three-dimensional micropolar theory of elasticity with free fields of displacements and rotations is constructed in thin domain of the shell. This boundary-value problem is singularly perturbed with small geometric parameter. Internal iteration process and boundary layers are constructed, problem of their jointing is studied and boundary conditions for each of them are obtained. On the basis of the results of the internal boundary-value problem the asymptotic two-dimensional model of micropolar elastic thin shells is constructed. Further, the qualitative aspects of the asymptotic solution are accepted as hypotheses and on the basis of them general applied theory of micropolar elastic thin shells is constructed. It is shown that both the constructed general applied theory of micropolar elastic thin shells and the classical theory of elastic thin shells with consideration of transverse shear deformations are asymptotically confirmed theories.
文摘The sources about the seasonal and blossoming biology of some Ferula L. (F angrenii, F. ovina, F. dshizakensis, F. helenae) types which can be found in Western Pamir-Alay have been given in the article.
文摘The article presents the features of biology and ecology, growth and development of various </span><i><span style="font-family:Verdana;">Lycium</span></i><span style="font-family:Verdana;"> L</span></span><span style="font-family:Verdana;">.</span><span style="font-family:""><span style="font-family:Verdana;"> species in different ecological conditions of Uzbekistan. The distribution area covers mainly semi-desert and desert zones of Uzbekistan and the description of co-growing coenoses is presented. Based on the study of ecological and biological properties and economically valuable characteristics of </span><i><span style="font-family:Verdana;">Lycium</span></i><span style="font-family:Verdana;"> L</span></span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> species, ecologically significant species were selected as a source material for introduction into culture and use in pharmacology. Useful properties and harms are presented.
文摘It is shown that the mean value of the capacitive current arising in the p-n-junction in a microwave field is zero, and the average value of the active current independently of the current value is different from zero and is equal to the current generated by the diode.
文摘It is shown that the increase in the current of an asymmetric p-n-junction, caused by perturbation of potential barrier height and increasing recombination current in a strong microwave field, is suppressed by light generated photo carriers, leading to the displacement of current-voltage characteristics of p-n-junction into the direction of smaller current values.
文摘It is shown that the nonideality coefficient m actually depends on the electron temperature Te, and the hole temperature Th. We get more general expression for the nonideality coefficient, taking into account the concentration of electrons and holes, as well as their temperature, coefficient and diffusion length, the temperature of the phonons, the applied voltage, and the height of the potential barrier.
文摘The riparian (tugai) forest ecosystems of Central Asia are a biodiversity hotspot with unique many trees and shrubs. Intense human pressure and global warming have caused habitat destruction in Zerafshan State National park and it’s 23.5 ha. There grow more than 300 higher plants. We analysed the wild flora and the remains of the species diversity that previously existed on the site of the forestry enterprise, the modern biodiversity of trees and shrubs in the described territory are represented by 52 species from among representatives of 21 plant families. These monitoring and results indicated that some tree species might in the near future become extinct in the wild. We therefore recommend that the local people be encouraged to stop using these trees.
文摘Central Asia is one of the main centers of origin of bulbous geophytes, including the family Amaryllidaceae Juss. The anatomical features of many endemic, red-book bulbous geophytes are still poorly understood. The article presents the results of a structural study of the inflated part of the stem (fistular), stem and pedicels of an endemic A. praemixtum species grow in two different environmental conditions in the Aktau mountain Nurata Range (Uzbekistan, Province Navoi) and in the conditions of introduction in the Tashkent Botanical Garden (Uzbekistan, Tashkent city). Diagnostic signs of vegetative organs were revealed and various combinations of xeromorphic and mesomorphic signs were determined. Comparative anatomical study of vegetative organs of A. praemixtum is of great theoretical and practical importance in relation to taxonomy and ecology.
基金partly supported by Research Grants FZ-20200929344 and F-FA-2021-510 of the Uzbekistan Ministry for Innovative DevelopmentTUBITAKSCOAP3 for their support。
文摘In this study,we examine the effects of weak gravitational lensing and determine the shadow radius around black holes within the Dyonic ModMax(DM)spacetime,also accounting for models with nonuniform plasma distributions.By analyzing various gravitational lens models,we compare corrections to vacuum lensing due to gravitational effects within plasma and plasma inhomogeneity,finding that these effects could be observed in hot gas within galaxy clusters.Starting with the orbits of photons around a black hole in DM,we investigate the shadow and weak gravitational lensing phenomena.Utilizing observational data from the Event Horizon Telescope for M87*and SgrA*,we constrain parameters within DM gravity.To connect our findings to observations,we examine the magnification and positioning of lensed images,along with the weak deflection angle and magnification for sources near different galaxies.
文摘The article presents the results of studies of the anatomical structure of the vegetative organs of </span><i><span style="font-family:Verdana;">Allium </span><span style="font-family:Verdana;">kysylkumi</span></i><span style="font-family:Verdana;"> of the Amaryllidaceae family, which grows in the conditions of Kyzylkum (Kokchatau outlier mountain). The characteristic diagnostic features have been determined: the outer membrane of epidermal cells is well developed by the outer folded cuticle, cutinized and more thickened;leaves are amphistomatic;stomata are the most submerged, </span><span style="font-family:Verdana;">anomocytic</span><span style="font-family:Verdana;"> type;isolateral-palisade type of leaf mesophyll;the conducting bundles </span><span style="font-family:Verdana;">are closed, collateral and are arranged in two rows, of which the upper side is represented only by small bundles, in the lower row, 3 large bundles alternate with one small bundle;peduncle and peduncle, parenchymal-beam type of structure;the epidermis is single-row, fold</span><span style="font-family:Verdana;">ed cuticle with more thickened and cutinized;the crustal parenchyma is thin-walled, round-oval, chlorophyll-bearing;the presence of lactic acid is in the cow parenchyma;the primary cortex is separated from the central cylinder by a ring of sclerenchyma;the central cylinder is extensive;closed collateral-type conductive bundles.</span><b> </b><span style="font-family:Verdana;">In the vegetative organs of </span><i><span style="font-family:Verdana;">Allium </span><span style="font-family:Verdana;">kysylkumi</span></i><span style="font-family:Verdana;">, especially in the leaf, xeromorphic characters are pronounced, which indicates the fitness of this species in natural habitat. The revealed structural diagnostic signs of vegetative organs are </span><span style="font-family:Verdana;">species-specific,</span><span style="font-family:Verdana;"> and show the adaptation of this species to its natural habitat, these micromorphological signs are taxonomic significance for distinguishing and identifying </span><i><span style="font-family:Verdana;">Allium</span></i><span style="font-family:Verdana;"> species.
文摘The study of the parameter space of chaotic systems is complicated by its high dimensionality (multi-parametricability). Two approaches to the study of chaotic systems are presented: multi-parameter analysis and optimal suppression of chaotic dynamics. For non-autonomous chaotic systems, this is the way to compare the effectiveness of various correction parameters that provide optimal removal of irregular dynamics. For the class of autonomous chaotic systems, this is the way to investigate the optimal conditions of super-stable behavior for the chaotic system.
