Saint Petersburg Mining University
  • Saint Petersburg, Russia
Recent publications
We report on the fabrication and studies of Ø100 μm half-disk lasers with an active region based on InGaAs/GaAs quantum dots providing very high modal gain. Such resonators support whispering gallery modes propagating at the cavity periphery. The microlasers show directional light outcoupling: continuous-wave output power emitted from the flat side reaches 17 mW, which is about 7 times greater than the power emitted from the back semicircular side. Single-mode lasing in a wide range of the injection currents is observed. P-side down bonding of the devices onto Si-board allowed increasing the maximum optical power to more than 30 mW and the lasing was observed up to 93°C. The 3 dB modulation bandwidth of 4.6 GHz was measured likely being limited by RC-parasites.
Transversal structural elements in cross-striated muscles, such as the M-band or the Z-disc, anchor and mechanically stabilize the contractile apparatus and its minimal unit—the sarcomere. The ability of proteins to target and interact with these structural sarcomeric elements is an inevitable necessity for the correct assembly and functionality of the myofibrillar apparatus. Specifically, the M-band is a well-recognized mechanical and signaling hub dealing with active forces during contraction, while impairment of its function leads to disease and death. Research on the M-band architecture is focusing on the assembly and interactions of the three major filamentous proteins in the region, mainly the three myomesin proteins including their embryonic heart (EH) isoform, titin and obscurin. These proteins form the basic filamentous network of the M-band, interacting with each other as also with additional proteins in the region that are involved in signaling, energetic or mechanosensitive processes. While myomesin-1, titin and obscurin are found in every muscle, the expression levels of myomesin-2 (also known as M-protein) and myomesin-3 are tissue specific: myomesin-2 is mainly expressed in the cardiac and fast skeletal muscles, while myomesin-3 is mainly expressed in intermediate muscles and specific regions of the cardiac muscle. Furthermore, EH-myomesin apart from its role during embryonic stages, is present in adults with specific cardiac diseases. The current work in structural, molecular, and cellular biology as well as in animal models, provides important details about the assembly of myomesin-1, obscurin and titin, the information however about the myomesin-2 and -3, such as their interactions, localization and structural details remain very limited. Remarkably, an increasing number of reports is linking all three myomesin proteins and particularly myomesin-2 to serious cardiovascular diseases suggesting that this protein family could be more important than originally thought. In this review we will focus on the myomesin protein family, the myomesin interactions and structural differences between isoforms and we will provide the most recent evidence why the structurally and biophysically unexplored myomesin-2 and myomesin-3 are emerging as hot targets for understanding muscle function and disease.
The results of calculations of permeability of coal beds by Kozeny-Carman model are reported. The applicability of the model is proven in the case of known total porosity and specific surface of pore volume of fossil coal that are measured by small-angle neutron scattering experiments. By means of the fractal theory, it is shown that when the depth of coal bed increases, the reduction of the fractal dimension results in enlarged volume of macropores that provide enhanced permeability and gas content of deep seated coal beds.
Most of the light from blazars, active galactic nuclei with jets of magnetized plasma that point nearly along the line of sight, is produced by high-energy particles, up to around 1 TeV. Although the jets are known to be ultimately powered by a supermassive black hole, how the particles are accelerated to such high energies has been an unanswered question. The process must be related to the magnetic field, which can be probed by observations of the polarization of light from the jets. Measurements of the radio to optical polarization—the only range available until now—probe extended regions of the jet containing particles that left the acceleration site days to years earlier1–3, and hence do not directly explore the acceleration mechanism, as could X-ray measurements. Here we report the detection of X-ray polarization from the blazar Markarian 501 (Mrk 501). We measure an X-ray linear polarization degree ΠX of around 10%, which is a factor of around 2 higher than the value at optical wavelengths, with a polarization angle parallel to the radio jet. This points to a shock front as the source of particle acceleration and also implies that the plasma becomes increasingly turbulent with distance from the shock. Polarization measurements are reported for the blazar Mk501, revealing a degree of X-ray polarization that is more than twice the optical value and supporting the shock-accelerated energy-stratified electron population scenario.
This study is devoted to assessing the potential for accumulating heavy metals (Fe, Mn, Cu, Zn) of nine species of aquatic and coastal plants growing in the water area of the Okhta River (St. Petersburg, Russian Federation). The list of studied species included the following: hornwort (Ceratophyllum demersum L.), water soldier (Stratiotes aloides L.), yellow water-lily (Nuphar lutea (L.) Sm.), arrowhead (Sagittaria sagittifolia L.), broadleaf cattail (Typha latifolia L.), water arum (Calla palustris L.), acute sedge (Carex acuta L.), reed canary grass (Phalaris arundinacea L.), and meadowsweet (Filipendula ulmaria (L.) Maxim.). The values of the bioconcentration factor for particular plant tissues were calculated. It has been established that the concentrations of metals in plant tissues can be thousands and tens of thousands of times higher than their content in water. At the same time, the ability of plants to accumulate metals varies greatly and depends on a number of factors, such as environmental conditions, the growing season, the type and ecological group of the plant. The study also attempts to determine the spatial and temporal dynamics of the content of heavy metals in higher aquatic plants. The main difficulties in data interpretation are indicated. The data obtained show the different significance of the study macrophyte species both for bioindication purposes and for use in wastewater treatment. The possibility of using such species as Sagittaria sagittifolia L., Typha latifolia L., Ceratophyllum demersum L., and Calla palustris L. for bioremediation is substantiated.
One of the most controversial and discussed issues related to the development of the hydrocarbon raw material base in recent years is the issue of exploring the possibilities of involvement in industrial development accumulations associated with high-carbon shale complexes that are widespread in Russia. Interest therein is supported by the system of benefits provided by the Government for low-permeability reservoirs and special preferential conditions for geological exploration provided to subsurface users in recent years. An important effect was also achieved by developing a methodology for reserves assessment and placing on the state balance a whole series of fields with oil deposits in the Domanik formation of the Volga-Ural oil and gas province (OGP). Simultaneously, the assessment of the potential of high-carbon formations in the Russian Federation mainly continues to be the subject of scientific research without an applied component, due to its inapplicability for selecting both the most significant areas for exploration and the possibilities of using it to justify investments. Here, the uncertainty is related to the estimation of possible production levels with an unclear correlation between development technologies, filtration and reservoir properties, and the potential of high-carbon strata. This study discusses two approaches that allow assessment of the potential of the main high-carbon strata distributed in Russia.
The article is devoted to the optimization of the working cycle of the production line. The article describes a simulation model, which is aimed at increasing the efficiency of technological preparation of production by optimizing the technological parameters of the production line by synchronizing the duration of technological operations. Synchronization of technological operations is carried out by choosing rational cutting parameters for each technological transition. Determination of rational cutting parameters is based on the calculation of the total processing error, which improves the quality of products. The article considers an example of optimization of the working cycle of a production line for the manufacture of a “Bushing” part from titanium alloy VT41. The choice of rational cutting parameters for each technological transition was based on the analysis of the total value of interruptions in the production line. Taking into account the permissible cutting parameters for each technological transition, calculated on the basis of the total processing error, such values were taken as rational values at which the total amount of breaks was minimal. The simulation model described in the article makes it possible to increase the efficiency of the production line, as well as to improve the quality of products due to a preliminary assessment of the accuracy of individual dimensions.
The study was carried out in order to experimentally define parameters of the shaped charge jet and energy distribution in it. Experiments were performed using ultra-high-speed SFR-2M camera and shadow installation IAB-451. Performance parameters of elongated shaped charges with different cavity configurations were examined. Parameters of detonation waves in charges of different configurations were estimated. For charges of the ESC-7M, ESC-11M and ESC-13M types, it was found that the detonation velocities are determined by the density of the press-fitting of the compositions and range from 8200÷9000 m/s. Motion speed dependencies of charge shell material were established for different designs with and without taking into account material strength. Values of incidence angles between shaped charge jet front and lateral surface of the charge were identified. Developed mathematical model allows to determine parameters of the «jet-slug» system not only for the initial moment of system formation, but for each subsequent step up to system demolition. As a result of this study, it was proposed to expand the scope of the use of elongated shaped charges in mining, while such charges are often used only in special blasting.
The article features of dynamics of post-traumatic symptoms and displays of personal desadaptation of the police officers who have carried out operational and service tasks in special conditions are considered. The empirical study involved 195 police officers aged from 26 to 32 years. Techniques: the standardized multifactorial method of research of the personality (L.N. Sobchik), the questionnaire of traumatic stress I.O. Kotenev. As a result of research it is established, that over time, changes of personal features, posttraumatic symptoms often proceed latently in the form of progredient (towards increase or decrease) or "wave-like" orientation (with alternation of periods of improvement and deterioration of a condition). Symptoms of "intrusion", "avoidance" and physiological hyperexcitability increase from the moment of performance of operational and service tasks in special conditions, and stabilize after three years. Neurotic control, pessimism and social introversion increase linearly. Optimism, distress and flashbacks of psychotraumatic events decrease progrediently. In the post-traumatic period from 1.5 to 3 years, the number of persons with signs of emotional lability, rigidity, non-productive tension and chronic fatigue grows. After 4 years, impulsiveness and aggravation increase, and the ability to withstand emotional stresses decreases. Practical recommendations for psychological rehabilitation of the specified negative manifestations are offered.
Magnetars are neutron stars with ultra-strong magnetic fields, which can be observed in x-rays. Polarization measurements could provide information on their magnetic fields and surface properties. We observe polarized x-rays from the magnetar 4U 0142+61 using the Imaging X-ray Polarimetry Explorer, finding a linear polarization degree of 13.5 ± 0.8% averaged over the 2 to 8 keV band. The polarization changes with energy: the degree is 15.0 ± 1.0% at 2 to 4 keV, drops below the instrumental sensitivity around 4 to 5 keV, and rises to 35.2 ± 7.1% at 5.5 to 8 keV. The polarization angle also changes by 90° around 4 to 5 keV. These results are consistent with a model in which thermal radiation from the magnetar surface is reprocessed by scattering off charged particles in the magnetosphere.
Countering the growing carbon emissions of the global economy is one of the cornerstones of the modern concept of sustainable development. While developed countries have been actively and willingly engaged in this struggle over the past decades, the question of how countries with substantial reserves of primary energy resources should be involved in these processes is still debatable. At the same time, the role of these countries in shaping the global carbon emissions is so visible that without adequate measures to stimulate industry in these countries, the efforts made by developed countries will have only a fragmented and insufficient effect. This article provides an overview of the key tools used to intensify the development of renewable energy as the main driver of reducing the carbon intensity of the energy sector, as well as an analysis of their significance from the perspective of countries with a resource-based economy. It shows the differences in the perception of the ongoing global processes of greening the energy sector and proposes key vectors that will generate interest in resource-economy countries. It was found that: (1) renewable energy is a promising solution to reduce carbon emissions, but only for countries that do not possess vast reserves of fuel raw materials; (2) focusing on a limited list of climate policies has devastating long-term consequences for the fossil energy industries, as seen in the decline in investment in exploration, which is a threat for global energy security; (3) engagement of countries with resource-based economy in the fight against the growth of carbon dioxide emissions should be based on the realization of their resource potential through the development of circular economy technologies, like carbon capture, utilization, and storage.
We develop and analyze a new method for manipulation of energy in a quantum harmonic oscillator using coherent, e.g., electromagnetic, field and incoherent control. Coherent control is typically implemented by shaped laser pulse or tailored electromagnetic field. Incoherent control is implemented by engineered environment, whose mean number of excitations at the frequency of the oscillator is used as a control variable. An approach to coherent and incoherent controls design based on the speed gradient algorithms in general, finite and differential forms is proposed. It is proved that the differential form is able to completely manipulate the energy of the oscillator: an arbitrary energy can be achieved starting from any initial state of the oscillator. The key instrument which allows for complete energy manipulation in this case is the use of the engineered environment. A robustified speed-gradient control algorithm in differential form is also proposed. It is shown that the proposed robustified control algorithm ensures exponential stability of the closed loop system which is preserved for sampled-data control.
This work describes the experience in developing and testing software for oil industry automation control systems based on the simulation of technological processes and control systems combined in virtual reality, this approach is called virtual commissioning and is widely used in the world both to create automated process control systems and to simulate interactions between different systems.
The results of SIMS and EPMA studies on the silicate minerals and bulk compositions (SEM-EDS) of porphyritic and nonporphyritic chondrules from Elenovka and Knyahinya meteorites are reported. The trace element composition of silicate minerals (olivine, low-Са pyroxene) in equilibrated ordinary chondrites (EOC) has not been affected considerably by thermal metamorphism on the chondritic parent bodies. Therefore, equilibrated chondrites can be used for chondrule-forming processes studies. Low-Са pyroxene in nonporphyritic chondrules contains higher REE, Ba, Sr concentrations than that in porphyritic chondrules at similar trace element concentrations in the olivine of chondrules. The data obtained indicate that the formation of non-porphyritic chondrules was triggered by an increase in the cooling rate of chondrules upon the formation of pyroxene, rather than a difference in the initial conditions of chondrule formation. Higher refractory incompatible element (Nb, LREE) concentrations in the olivine of chondrules than those in the olivine of the matrix and contrasting trace element (Zr, Sr, Cr, REE) concentrations in the low-Са pyroxene of the chondrules and the matrix suggest that the matrix and chondrules of the meteorites formed in one reservoir under different physico-chemical conditions (density, redox state, rotation speed, homogeneity, temperature, shocks, electrical discharge, etc.).
In this study, we extend the three‐regime bubble model of Pang et al. (2021, Journal of Econometrics, 221(1):227‐311) to allow the forth regime followed by the unit root process after recovery. We provide the asymptotic and finite sample justification of the consistency of the collapse date estimator in the two‐regime AR(1) model. The consistency allows us to split the sample before and after the date of collapse and to consider the estimation of the date of exuberation and date of recovery separately. We have also found that the limiting behavior of the recovery date varies depending on the extent of explosiveness and recovering. This article is protected by copyright. All rights reserved.
From 1914 onwards, leader‐centric imagery became a prominent component of hegemonic Russian political discourse, and these early cults of military and political leaders served as inspiration for later veneration of Lenin and Stalin. The case of Leon Trotsky, a top leader of the Red Army and the Soviet state, is of crucial importance for understanding the political universe of the revolutionary era. However, among the many biographies of Trotsky, including those which focus heavily on his Civil War‐era political activities, few consider how the symbolic image of Trotsky was manifested in political communication. This article addresses the genesis of the Trotsky cult in its early stage during the Russian Civil War, asking who and how participated in the formation of the cult, and what its meanings were in the context of the revolutionary milieu. Based on an analysis of dominant narratives in the Soviet press, including Trotsky's personal newspaper, as well as of the language of the people's letters to the leader, the article concludes that the cult‐building is best understood as a part of multiple, local, often individual initiatives, rather than as a conscious, well‐coordinated, top‐down political propaganda strategy of Soviet officials.
Introduction. Understanding the grounds of the law-abiding behavior of young people is a socially significant, but poorly studied research domain. Knowledge of the psychological causes of law-abiding behavior is important for the implementation of preventive work with deviant youth and the socialization of the younger generation. Contemporary scientific ideas do not have sufficient information about the role of the entire system of relations of the subject with the social environment for the motivation of law-abiding behavior, focusing on the study of the role of its specific participants - family members, relatives, friends and colleagues. The study is focused on the relations with the social environment as a motive for law-abiding behavior. For this purpose, the study performs a cross-cultural assessment of these relationships in Chinese and Russian youth samples. Methodology, methods and techniques. The methodological basis of the study is the social network approach to the social environment studies. This approach makes it possible to describe the social environment as a quasi-social group, the basis (center) of which is the subject, while the rest of the participants are connected to the subject through social and psychological relations. Application of this approach reveals the significance of the social environment as a motive for law-abiding behavior, showing the effect of relations with the social environment on delinquent behavior readiness. Cross-cultural studies represent the research strategy. Information collecting method is a questionnaire analyzing the social relations and the motives of law-abiding behavior, as well as a standardized self-report measuring the subjective interaction features. Results processing method: descriptive statistics, non-parametric alternative to one-way analysis of variance - Kruskal-Wallis H-test. Survey sample: 100 people, consisted of Russian (50 people) and Chinese (50 people) students, of the similar age and gender. Results: the social environment features have been determined affecting law-abiding behavior and making up motivation: (1) Social environment parameters (volume, homogeneity, interaction difficulties) within the average (standard) values do not affect the law-abiding behavior of young people; (2) Self-assessment of interaction with the social environment enhances the motivation for law-abiding behavior for Russian youth; (3) Social support from individuals in the social environment enhances the motivation for law-abiding behavior in the Russian and Chinese sampling; (4) The system of motives for law-abiding behavior can be represented as emotional, social, personal and rational motives developed under the social environment influence. Scientific Novelty. The data obtained expand the understanding of the motivating role of relationships with the social environment, showing that the help and support of others, as well as self-assessment of interaction with the social environment, enhances the law-abiding behavior motivation. Practical Significance. The represented classification of the motives of law-abiding behavior can be applied to develop procedures for measuring and evaluating the readiness of young people to comply with legal standards.
Introduction. Aggressiveness is one of the forms of manifestation of the personality deviations and is differentiated by the degree of intensity from its normal indicators to extreme ones. In the activities of police officers, aggressiveness acts as a defense mechanism, which often exceeds the limits of moderately protective reactions and reaches the level of extreme aggression, manifested as an inadequate response to the exposure of the environmental stimuli. Theoretical analysis of the phenomena of aggressiveness and hostility, as well as the peculiarities of their manifestation in the professional activities of police officers shows the propensity of employees to aggressive and hostile forms of behavior, characterized by stability and stereotypes, determined by both the emotions of fear and formed personality deformities, pathological properties of character. The need for self-control of emotional reactions and lack of competence in assessing the emotional states of others increases the risks of aggressiveness and deviant behavior of police officers and forms a type of destructive personality. For the sphere of professional activity this is a significant obstacle in ensuring its effectiveness and reliability. Prevention of aggressiveness and hostility requires the development and implementation of technology that ensures the development of negative affects regulation skills, emotional states and behavior. The purpose of the study was to identify the degree of intensity of various indicators of aggressiveness and hostility of police officers, as well as to analyze their changes due to the application of the technology development abilities of emotional-volitional self-regulation. Methodology, methods and techniques. A complex of empirical and mathematical methods was used in the analysis of changes in the aggression indicators. Empirical data were obtained with the following techniques: the scale of neuropsychic adaptation (J.N. Gurvich), the method «Types of aggressiveness» (L.G. Pochebut), the Cook-Medley Hostility Scale. Data processing was performed using a specialized software package IBM SPSS Statistics 23 and Microsoft Excel. The research used a comparative analysis of empirical data. A group of employees (n=82) with signs of neuropsychic maladaptation of a nonpathological nature was separated from the total sample of subjects (n=253) and divided into an experimental (n=41) and a control group (n=41). In the experimental group, classes were organized for the development of abilities to emotional-volitional self-regulation (forming experiment). Results and interpretation. A comparative analysis of the values of aggressiveness and hostility of police officers before and after the experiment showed reliable differences for 3 indicators out of 9 (33.33%): self-aggression, total aggressiveness index, and hostility. In the values of the control and experimental groups during the realization of the ascertaining experiment no reliable differences were revealed, after the experiment statistically significant differences in the indicators were found: verbal aggression, emotional aggression, self-aggression, total aggressiveness index, cynicism, aggressiveness, hostility. Scientific novelty of the study lies in identifying the indicators of aggression and hostility of police officers experiencing states of neuropsychic maladaptation, in clarifying the role of abilities to emotional and volitional self-regulation in the prevention of aggression and hostility, in determining the parameters of changes in the intensity of aggressive and hostile manifestations in the experiment. Practical Significance. The change in the indicators of aggressiveness and hostility, identified as a result of the forming experiment, indicates the effectiveness of the technology development abilities to emotional and volitional self-regulation and on this basis allows to develop author programs to manage negative emotions and implement the prevention of deviant behavior of police officers.
In modern Russia many people become victims of crimes every day. Insufficient adaptation of Russians to ensure personal security is caused by their personal criminal vulnerability (victimization). The victimological situation in the country, without exaggeration, can be assessed as extremely tense, revealing the need to create a system of measures to ensure the proper security of citizens and legal entities. The solution of this problem is impossible without a deep study of the real state of victimization of the population. On the basis of official criminal statistics, the authors present the dynamics, state, structure of the negative consequences of crime. The assessment of material damage from crimes committed in the country is given. The specificity of arrays of victims of crimes in transport is shown in comparison with the general array of victims of crimes. The geography of criminal victimization is reflected. The nature of latent victimization is investigated. The ratio of criminal victims among legal entities and individuals is considered. The results of the proposed analysis of criminal victimization of the population will make it possible to make management decisions aimed at effective fighting crime.
The article deals with one of the urgent problems of modern educational practice – the problem of prevention of deviant behavior of adolescents as a necessary condition for the progressive and safe development of society and civilization as a whole. When examining the problem under consideration, the authors focus on the study of the phenomenon of deviant behavior, since the effective implementation of preventive educational practice requires a deeper and more comprehensive understanding of the essence of deviant behavior. On the basis of this statement, the authors have studied the main types of deviant behavior, its leading socio-psychological determinants, the system of the most adopted scientific approaches to the interpretation of this scientific category, as well as pedagogical strategies for the prevention of this type of behavior. The complex of applied forms and methods of pedagogical prevention crucially determines the effectiveness of preventive measures, and therefore, this aspect is also reflected in our article. Particular attention is paid to the problem of spiritual and moral education of the younger generation. Achieving a high level of spirituality and morality both of an individual and society is considered as a kind of unconditional guarantee of preventive work to prevent adolescent deviance.
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1,868 members
Ekaterina Samylovskaya
  • Department of History
Sergey Tsirel
  • Geomechanics center
Alexander Tatarenko
  • Department of Electrical and Electronics Engineering
Viktor Alekseev
  • Department of Geology
A. S. Mustafaev
  • General & Technical Physics
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Vladimir Litvinenko
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