Non-circular semiconductor nanorings of type I and II: Emission kinetics in the exciton Aharonov-Bohm effect

Transition energies and oscillator strengths of excitons in dependence on magnetic field are investigated in type I and II semiconductor nanorings. A slight deviation from circular (concentric) shape of the type II nanoring gives a better observability of the Aharonov-Bohm oscillations since the ground state is always optically active. Kinetic equations for the exciton occupation are solved with acoustic phonon scattering as the major relaxation process, and absorption and luminescence spectra are calculated showing deviations from equilibrium. The presence of a non-radiative exciton decay leads to a quenching of the integrated photoluminescence with magnetic field.Comment: The first version submitted to Phys. Rev. B on April 16, 2007. Revised (this) version on July 31, 200

СТАН ТА ТЕНДЕНЦІЇ МІЖБЮДЖЕТНОГО РЕГУЛЮВАННЯ В УКРАЇНІ В УМОВАХ ФІСКАЛЬНОЇ ДЕЦЕНТРАЛІЗАЦІЇ

A balanced socio-economic development of any country is closely related to the efficiency of the system of intergovernmental relations, which should be aimed at optimizing the process of fiscal decentralization and clear definition of the powers of local government. Interbudgetary regulation in Ukraine reflects processes of the national and political importance and is of great importance in the composition of intergovernmental fiscal relations, which priority is growing in terms of decentralization reforms. Purpose. The main objectives of this study are: to summarize a complex task that is resolved in the process of budgetary control; to analyze the dynamics of revenues of the consolidated budget of Ukraine in 2007-2016 and the proportion of own local revenues in GDP; to distinguish formation features of Ukrainian local budgets by region; to analyze volumes of local budgets per capita in terms of area; to highlight the leverage rate of local budgets; to analyze the share of interbudget transfers in total local budgets. Results. The study is a synthesis of the complex challenges that must be resolved in the process of budgetary control, such as: balancing the budget; foster the interest of local governments in the maximum revenue mobilization; reallocation of existing budgetary resources, taking into account local features. The dynamics of the revenues of the consolidated budget of Ukraine in 2007-2016 was analyzed and concluded that the proportion of own local revenues in GDP tended to decrease with a simultaneous increase in the share of the interbudget transfers from the state budget. Abovementioned resulted in the ensuring of a stable share of local budgets in the GDP structure (at 14-15%). As a result of the intergovernmental fiscal decentralization reform by the results of 2016 the share of own revenues of local budgets Ukraine in GDP rose to 7.2%, or 1.1% compared to 2015 with a simultaneous decrease in the interbudget transfers share from the state budget to 8.2% (0.6% compared to 2015). Analyzed the share interbudget transfers in total local budgets, which for a long period tended to increase (from 47.2% in 2007 to 53.4% in 2016), which is contrary to the basic principles of fiscal decentralization. Conclusion. Grounded features of Ukrainian local budget revenues by region and proved that the unevenness of income between regions of Ukraine are often equivalent to the level of industrial production. Analyzed volumes of local budgets per capita in terms of area. Presented the list of influence instruments on local budgets indexes of incomes, including the increase in the minimum wage, inflation, continuing reform of the budget system in the direction of fiscal decentralization and transfer volumes.Представлен комплекс задач, который должен решаться в процессе межбюджетного регулирования, проанализирована динамика доходной части сводного бюджета Украины в 2007-2016 гг. и удельный вес собственных доходов местных бюджетов в структуре ВВП, выделены особенности формирования доходов местных бюджетов Украины по регионам. Проанализированы объемы доходов местных бюджетов на душу населения в разрезе территорий, освещены рычаги влияния на показатель доходов местных бюджетов, проведен анализ удельного веса межбюджетных трансфертов в общей структуре местных бюджетов.Узагальнено комплекс завдань, що має вирішуватись у процесі міжбюджетного регулювання, проаналізовано динаміку дохідної частини зведеного бюджету України у 2007–2016 рр. та питому вагу власних доходів місцевих бюджетів в структурі ВВП, виокремлено особливості формування доходів місцевих бюджетів України за регіонами. Проаналізовано обсяги доходів місцевих бюджетів на душу населення у розрізі територій, висвітлено важелі впливу на показник доходів місцевих бюджетів, здійснено аналіз питомої ваги міжбюджетних трансфертів у загальній структурі місцевих бюджетів

Вивчення параметрів гострої та підгострої токсичності препарату “Рибохін” на моделі коропа

The goal of the work was to study of acute and subacute toxicity parameters of “Rybokhin” biological product (AI – chloroquine refer to derivatives 4-aminohinolines) on the model of carp. This drug is effective in the treatment of diseases caused by parasitic Protozoa and Monogenea. Carp scales of two years old were used in experiments. To determine acute toxicity, the fish were prescribed with chloroquine (by AI) in doses of 100; 200; 300; 400; 500; 600; 800; 1000 mg/kg of live weight. Two experimental and control fish groups of 30 individuals each were formed to determine subacute toxicity of “Rybokhin”. Experimental groups of fish were prescribed with “Rybokhin” in a dose (by AI) of 50 mg/kg and 10 mg/kg for two consecutive days. Blood samples were collected from six fish species from each group for clinical and biochemical indicators after 48 hours, 7, 14, 21 and 28 days. The hemoglobin content, number of red blood cells and leukocytes blood were determined. The intensity of peroxide oxidation of lipids (PОL), catalase activity, level of total antioxidant capacity (TAC), total proteins, albumin, globulins and glucose, circulating immune complexes (CІC) and seromucoids concentration, level of enzymatic activity: aspartate transaminase (АSТ), alanine transaminase (АLТ), ά-amylase blood plasma were determined. According to the research results, indicators of acute toxicity for carp were determined, namely LD50 of chloroquine is 528.66 ± 68.01 mg/kg; LD16 – 224.512 mg/kg; LD84 – 832.81 mg/kg; LD100 – 984.89 mg/kg, which indicate that the drug is low-toxic to fish (belongs to the fourth group of toxicity). When administrating of 50.0 mg/kg of “Rybokhin” (by AI) twice a day, the most expressed metabolic changes in fish body were observed on 21 day after its last administration. Thus, the drug’s toxic impact is in proteinogram alteration, transamination processes and in decreasing of fish immune reactivity. It points to the prevalence of catalytic processes over anabolic. Metabolic alterations are obviously directed to the activation of detoxication processes with increased energy use in fish body after getting of higher dosage of the product. So, on 28 day of experiment, the major part of studied parameters retrieved to control level. It was found that when the product was administrated twice a day in the dosage 10.0 mg/kg (by AI), which is used for treatment of parasitic diseases, no reliable changes of clinical and biochemical indices were detected in fish blood during the experiment.Метою досліджень було визначити параметри гострої та підгострої токсичності препарату “Рибохін” (ДР – хлорохін, якій є похідною 4-амінохінолінів) на моделі коропа лускатого. Даний препарат є ефективним при лікуванні захворювань, спричинених паразитичними найпростішими (Protozoa) та моногенетичними присиcнями (Monogenea). У експериментах використовували коропа лускатого дволітнього віку. При визначенні гострої токсичності рибам задавали хлорохін (ДР) у дозах 100; 200; 300; 400; 500; 600; 800; 1000 мг/кг маси тіла. Для визначення підгострої токсичності препарату “Рибохін” було сформовано дві дослідні та контрольна групи риб по 30 особин у кожній. Рибі дослідних груп дві доби поспіль задавали препарат “Рибохін” у добовій дозі 50 мг/кг та 10 мг/кг маси тіла (за ДР). Через 48 год, 7, 14, 21 та 28 діб з метою клініко-біохімічних досліджень проводили відбір крові у шести особин риб з кожної групи. У крові визначали вміст гемоглобіну, кількість еритроцитів і лейкоцитів. У плазмі крові визначали інтенсивність процесів пероксидного окиснення ліпідів (ПОЛ), каталазну активність, рівень загальної антиокиснювальної активності (загальна АОА); вміст загальних протеїнів, альбуміну і глюкози; концентрацію циркулюючих імунних комплексів (ЦІК) і серомукоїдів; рівень ензиматичної активності: аспартатамінотрансферази (АсАТ), аланінамінотрансферази (АлАТ) і ά-амілази. За результатами досліджень визначено показники гострої токсичності для коропа: LD50 хлорохіну становить 528,66 ± 68,01 мг/кг; LD16 – 224,512 мг/кг; LD84 – 832,81 мг/кг; LD100 – 984,89 мг/кг маси тіла, які вказують, що препарат є малотоксичним для риб (належить до четвертої групи токсичності). Максимальну вираженість метаболічних змін в організмі риб за дворазового застосування препарату “Рибохін” в добовій дозі 50,0 мг/кг маси тіла (за ДР) виявляли на 21-шу добу після останнього задавання. Так, механізми токсичної дії препарату полягають у перебудовах в протеїнограмі і процесах переамінування та гальмуванні імунної реактивності в організмі риб, що вказує на превалювання катаболічних процесів над анаболічними. Метаболічні перебудови, очевидно, спрямовані на активацію процесів детоксикації з підвищенням енергетичних затрат в організмі риби внаслідок потрапляння підвищених доз препарату. Отже, на 28-му добу експерименту левова частка досліджених показників за значенням відновлювалась до контрольного рівня. Встановлено, що за дворазового введення препарату в добовій дозі 10,0 мг/кг маси тіла (за ДР), яка є лікувальною при боротьбі із паразитарними хворобами, у динаміці експерименту не виявляли достовірних змін клініко-біохімічних показників крові дослідних риб

Coupling between magnon and ligand-field excitations in magnetoelectric Tb3Fe5O12 garnet

The spectra of far-infrared transmission in Tb3Fe5O12 magnetoelectric single crystals have been studied in the range between 15 and 100 cm-1, in magnetic fields up to 10 T, and for temperatures between 5 and 150 K. We attribute some of the observed infrared-active excitations to electric-dipole transitions between ligand-field split states of Tb3+ ions. Anticrossing between the magnetic exchange excitation and the ligand-field transition occurs at the temperature between 60 and 80 K. The corresponding coupling energy for this interaction is 6 cm-1. Temperature-induced softening of the hybrid IR excitation correlates with the increase of the static dielectric constant. We discuss the possibility for hybrid excitations of magnons and ligand-field states and their possible connection to the magnetoelectric effect in Tb3Fe5O12.Comment: submitted to Phys. Rev. B on May 15th, 201

A new hard allotropic form of carbon: Dream or reality?

Abstract An unusual phase of carbon with the fcc crystal structure, the lattice constant of which is very close to that of diamond, was reported before in a number of publications. In all the published works, the existence of fcc carbon could not be unambiguously established, as only insignificant amounts of fcc carbon in mixture with other carbon modifications were obtained so far. The present work provides for the first time clear evidence for the existence of the carbon modification with the fcc crystal structure. Thin films consisting exceptionally of fcc carbon were obtained by various methods, namely by hot-filament CVD, plasma-assisted CVD and treatment of the diamond surface in hydrogen plasmas. Results of electron diffraction, Raman spectroscopy, AES, XPS, EELS and HRTEM of the films consisting of fcc carbon clearly indicate its unique crystal and electron structure. The micro-hardness of the films of fcc carbon was found to be equal to HV 0.01 = 250 which is quite different from the hardness of all the known carbon modifications

Stabilizing effect of nuclear quadrupole interaction on the polarization of electron-nuclear spin system in a quantum dot

Nuclear quadrupole interaction extends the limits imposed by hyperfine interaction on the spin coherence of the electron and nuclei in a quantum dot. The strain-induced nuclear quadrupole interaction suppresses the nuclear spin flip and makes possible the zero-field dynamic nuclear polarization in self-organized InP/InGaP quantum dots. The direction of the effective nuclear magnetic field is fixed in space, thus quenching the magnetic depolarization of the electron spin in the quantum dot. The quadrupole interaction suppresses the zero-field electron spin decoherence also for the case of non-polarized nuclei. These results provide a new vision of the role of the nuclear quadrupole interaction in nanostructures: it elongates the spin memory of the electron-nuclear system.Comment: 18 pages including 3 figures. Shortened version has been accepted for publication in Physical Review Letter

Finite-sample and asymptotic sign-based tests for parameters of non-linear quantile regression with Markov noise

One of the most noticeable features of sign-based statistical procedures is an opportunity to build an exact test for simple hypothesis testing of parameters in a regression model. In this article, we expanded a sing-based approach to the nonlinear case with dependent noise. The examined model is a multi-quantile regression, which makes it possible to test hypothesis not only of regression parameters, but of noise parameters as well

TRANSFORMATION OF APPROACHES IN MANAGEMENT AND MARKETING DUE TO THE COVID-19 PANDEMIC

The article summarizes and systematizes the theoretical and methodological principles of the management and marketing transformation caused by the COVID-19 pandemic. The topic of the research is relevant because the risks of most types of economic activities have increased in the conditions of the coronavirus crisis. These factors caused changes in consumer behavior and led to corresponding transformations in the management and marketing activities of business entities. The theoretical and analytical basis of the article includes fundamental works of scientists, statistical data of the State Statistics Service of Ukraine and leading consulting agencies. Methods of abstract-logical generalization, systematic and historical analysis and synthesis, monographic and survey-analytical, graphic methods were used in the research. It was determined that significant macroeconomic imbalances appeared in the conditions of the coronavirus crisis, the way of life changed, and society became less cohesive and mobile. Destruction of added value chains, logistics networks, decrease in total business activity of business entities led to a general deterioration of the population’s living standards and the parameters of their consumer confidence. It is shown that the COVID-19 pandemic contributed to changes in the hierarchy of consumer needs of Ukrainians, shifting the focus to physiological and safety needs. Therefore, most of the marketing trends during the coronavirus crisis in Ukraine are related to social distancing, seclusion of people and fear of disease. It has been established that the main tools of marketing management in the conditions of the COVID-19 pandemic have become personalized digital technologies aimed at meeting the consumers’ needs in conditions of social distancing and isolation. These technologies are managed as adaptively as possible, based on risk management, constant monitoring of feedback from focusing on social networks and services. It has been determined that the promising tools for the development of management, marketing and logistics in the post-pandemic world include the robotics of industry, trade and delivery of goods, the development of innovative technologies for air disinfection, household items and equipment, mass non-contact medical diagnostics, and home entertainment services