Classical approach in quantum physics

The application of a classical approach to various quantum problems - the secular perturbation approach to quantization of a hydrogen atom in external fields and a helium atom, the adiabatic switching method for calculation of a semiclassical spectrum of hydrogen atom in crossed electric and magnetic fields, a spontaneous decay of excited states of a hydrogen atom, Gutzwiller's approach to Stark problem, long-lived excited states of a helium atom recently discovered with the help of Poincar$\acute{\mathrm{e}}$ section, inelastic transitions in slow and fast electron-atom and ion-atom collisions - is reviewed. Further, a classical representation in quantum theory is discussed. In this representation the quantum states are treating as an ensemble of classical states. This approach opens the way to an accurate description of the initial and final states in classical trajectory Monte Carlo (CTMC) method and a purely classical explanation of tunneling phenomenon. The general aspects of the structure of the semiclassical series such as renormgroup symmetry, criterion of accuracy and so on are reviewed as well. In conclusion, the relation between quantum theory, classical physics and measurement is discussed.Comment: This review paper was rejected from J.Phys.A with referee's comment "The author has made many worthwhile contributions to semiclassical physics, but this article does not meet the standard for a topical review"

ПРОБЛЕМЫ ОЦЕНКИ ЭФФЕКТИВНОСТИ ИНДИВИДУАЛЬНО-НАКОПИТЕЛЬНОЙ МОДЕЛИ ПЕНСИОННОГО СТРАХОВАНИЯ

Topic. The article presents the results of actuarial analysis of the newest and most controversial component of the Russian system of compulsory pension insurance — accrual one. The prospect of its further development is estimated. The effectiveness of this method of pension provision is assessed by the author from the point of view the role and degree of performance of the institutional functions of the state pension system (i.e., ensuring a decent level of material security of pensioners), and the possibility of achieving the targets formulated in 2012 in the government’s Strategy for the long-term development of the pension system of the Russian Federation.Purpose. Development of economically reasoned justification of real financial relations between participants of the insurance pension system within the framework of individual-accrual models of pension provision.Methodology. The main methodological feature and originality of this study is a multi-factor analysis, using methods of comparative analysis and actuarial forecasting of the whole set of conditions for the formation and implementation by insured persons of their pension rights in the individual-accrual model (both external to the pension system and internal as well), not carried out in other studies on this problem.Results.The article presents the results of economicstudies of the national practice of formation and implementation of pension rights of workers in the framework of the individual-accrual pension insurance program. Those results can be used in substantiating the directions of reforming the accrual methods of pension provision:The degree of direct dependence of the pension system efficiency on external macroeconomic and demographic factors is proved.We formulated criteria for evaluating the effectiveness of the accrual component of the pension system.It is given the characteristic and the main tasks of the accrual component of the compulsory pension insurance system.There are proposed measures to improve the functioning of the accrual component in the existing Russian reality and in the long term.Conclusions. The accrual method of formation and realization of pension rights in specific long-term socioeconomic conditions does not allow the main categories of insured persons to form the level of pensions provided in the solidarity system, and also sharply increases the budgetary risks not only of the Russian Pension Fund (PFR), but also of the Federal budget.В статье представлены результаты актуарного анализа состояния самого нового и наиболее спорного компонента российской системы обязательного пенсионного страхования — накопительного. Оценивается перспектива его дальнейшего развития. Эффективность данного способа пенсионного обеспечения оценивается автором по роли и степени выполнения институциональных функций государственной пенсионной системы (обеспечения достойного уровня материального благосостояния пенсионеров) и достижения ориентиров, заданных правительственной Стратегией долгосрочного развития пенсионной системы Российской Федерации2012 г.Цель статьи — выработка экономически аргументированного обоснования реальных финансовых отношений между участниками страховой пенсионной системы в рамках индивидуально-накопительных моделей пенсионного обеспечения.Главной методологической особенностью и оригинальностью данного исследования является многофакторный анализ с использованием методов сравнительного анализа и актуарного прогнозирования, всего комплекса условий формирования и реализации застрахованными лицами своих пенсионных прав в индивидуально-накопительной модели (как внешних по отношению к пенсионной системе, так и внутрисистемных), не проводившийся в других исследованиях, посвященных данной проблеме.В статье представлены результаты профессионально-экономических исследований отечественной практики формирования и реализации пенсионных прав работников в рамках индивидуально-накопительной программы пенсионного страхования, которые могут быть использованы при обосновании направлений реформирования накопительных способов пенсионного обеспечения:доказана степень непосредственной зависимости эффективности пенсионной системы от внешних макроэкономических и демографических факторов;выработаны критерии оценки эффективности накопительного компонента пенсионной системы;дана характеристика и сформулированы основные задачи накопительного компонента системы обязательного пенсионного страхования;предложены меры по совершенствованию порядка функционирования накопительного компонента в существующих российских реалиях и в долгосрочной перспективе.В результате исследования сделан вывод о том, что накопительный способ формирования и реализации пенсионных прав в конкретных долгосрочных социально-экономических условиях не позволяет основным категориям застрахованных лиц сформировать уровень пенсий, обеспечиваемый в солидарной системе, а также он резко увеличивает бюджетные риски не только ПФР, но и федерального бюджета

Non-sequential double ionization below laser-intensity threshold: Anticorrelation of electrons without excitation of parent ion

Two-electron correlated spectra of non-sequential double ionization below laser-intensity threshold are known to exhibit back-to-back scattering of the electrons, viz., the anticorrelation of the electrons. Currently, the widely accepted interpretation of the anticorrelation is recollision-induced excitation of the ion plus subsequent field ionization of the second electron. We argue that another mechanism, namely simultaneous electron emission, when the time of return of the rescattered electron is equal to the time of liberation of the bounded electron (the ion has no time for excitation), can also explain the anticorrelation of the electrons in the deep below laser-intensity threshold regime. Our conclusion is based on the results of the numerical solution of the time-dependent Schr\"{o}dinger equation for a model system of two one-dimensional electrons as well as an adiabatic analytic model that allows for a closed-form solution.Comment: 6 pages and 3 figure

Incompressible magnetohydrodynamic modes in the thin magnetically twisted flux tube

Context. Observations have shown that twisted magnetic fields naturally occur, and indeed are omnipresent in the Sun’s atmosphere. It is therefore of great theoretical interest in solar atmospheric waves research to investigate the types of magnetohydrodynamic (MHD) wave modes that can propagate along twisted magnetic flux tubes. Aims. Within the framework of ideal MHD, the main aim of this work is to investigate small amplitude incompressible wave modes of twisted magnetic flux tubes with m ≥ 1. The axial magnetic field strength inside and outside the tube will be allowed to vary, to ensure the results will not be restricted to only cold plasma equilibria conditions. Methods. The dispersion equation for these incompressible linear MHD wave modes was derived analytically by implementing the long wavelength approximation. Results. It is shown, in the long wavelength limit, that both the frequency and radial velocity profile of the m = 1 kink mode are completely unaffected by the choice of internal background magnetic twist. However, fluting modes with m ≥ 2 are sensitive to the particular radial profile of magnetic twist chosen. Furthermore, due to background twist, a low frequency cut-off is introduced for fluting modes that is not present for kink modes. From an observational point of view, although magnetic twist does not affect the propagation of long wavelength kink modes, for fluting modes it will either work for or against the propagation, depending on the direction of wave travel relative to the sign of the background twist

Free Boundary Poisson Bracket Algebra in Ashtekar's Formalism

We consider the algebra of spatial diffeomorphisms and gauge transformations in the canonical formalism of General Relativity in the Ashtekar and ADM variables. Modifying the Poisson bracket by including surface terms in accordance with our previous proposal allows us to consider all local functionals as differentiable. We show that closure of the algebra under consideration can be achieved by choosing surface terms in the expressions for the generators prior to imposing any boundary conditions. An essential point is that the Poisson structure in the Ashtekar formalism differs from the canonical one by boundary terms.Comment: 19 pages, Latex, amsfonts.sty, amssymb.st

Hadronic Regge Trajectories: Problems and Approaches

We scrutinized hadronic Regge trajectories in a framework of two different models --- string and potential. Our results are compared with broad spectrum of existing theoretical quark models and all experimental data from PDG98. It was recognized that Regge trajectories for mesons and baryons are not straight and parallel lines in general in the current resonance region both experimentally and theoretically, but very often have appreciable curvature, which is flavor-dependent. For a set of baryon Regge trajectories this fact is well described in the considered potential model. The standard string models predict linear trajectories at high angular momenta J with some form of nonlinearity at low J.Comment: 15 pages, 9 figures, LaTe

Crown ethers: novel permeability enhancers for ocular drug delivery?

Crown ethers are cyclic molecules consisting of a ring containing several ether groups. The most common and important members of this series are 12-crown-4 (12C4), 15-crown-5 (15C5), and 18-crown-6 (18C6). These container molecules have the ability to sequester metal ions and their complexes with drugs are able to traverse cell membranes. This study investigated 12C4, 15C5 and 18C6 for their ability to increase solubility of ocular drugs and enhance their penetration into the cornea. Phase solubility analysis determined crown ethers’ ability to enhance the solubility of riboflavin, a drug used for the therapy of keratoconus, and these solutions were investigated for ocular drug permeation enhancing properties. Atomic absorption spectroscopy demonstrated crown ether solutions ability to sequester Ca2+ from corneal epithelia and crown ether mediated adsorption of riboflavin into the stroma was investigated. Induced corneal opacity studies assessed potential toxicity of crown ethers. Crown ethers enhanced riboflavin’s aqueous solubility and its penetration into in vitro bovine corneas; the smaller sized crown ethers gave greatest enhancement. They were shown to sequester Ca2+ ions from corneal epithelia, doing so loosens cellular membrane tight junctions thus enhancing riboflavin penetration. Induced corneal opacity was similar to that afforded by benzalkonium chloride and less than is produced using polyaminocarboxylic acids. However, in vivo experiments performed in rats with 12C4 did not show any statistically significant permeability enhancement compared to enhancer-free formulation

Modeling the Subsurface Structure of Sunspots

While sunspots are easily observed at the solar surface, determining their subsurface structure is not trivial. There are two main hypotheses for the subsurface structure of sunspots: the monolithic model and the cluster model. Local helioseismology is the only means by which we can investigate subphotospheric structure. However, as current linear inversion techniques do not yet allow helioseismology to probe the internal structure with sufficient confidence to distinguish between the monolith and cluster models, the development of physically realistic sunspot models are a priority for helioseismologists. This is because they are not only important indicators of the variety of physical effects that may influence helioseismic inferences in active regions, but they also enable detailed assessments of the validity of helioseismic interpretations through numerical forward modeling. In this paper, we provide a critical review of the existing sunspot models and an overview of numerical methods employed to model wave propagation through model sunspots. We then carry out an helioseismic analysis of the sunspot in Active Region 9787 and address the serious inconsistencies uncovered by \citeauthor{gizonetal2009}~(\citeyear{gizonetal2009,gizonetal2009a}). We find that this sunspot is most probably associated with a shallow, positive wave-speed perturbation (unlike the traditional two-layer model) and that travel-time measurements are consistent with a horizontal outflow in the surrounding moat.Comment: 73 pages, 19 figures, accepted by Solar Physic

ДИАГНОСТИКА ТЕХНОЛОГИЧЕСКИХ ХАРАКТЕРИСТИК МОЩНЫХ ТРАНЗИСТОРОВ С ПОМОЩЬЮ РЕЛАКСАЦИОННОГО ИМПЕДАНС–СПЕКТРОМЕТРА ТЕПЛОВЫХ ПРОЦЕССОВ

The efficient method of determining thermal parameters in high-power field-effect transistors has been developed and tested based on a study of transient processes during self heating by direct current. With the developed relaxation spectrometer of thermal processes differential distribution profiles of thermal resistance of KP723G transistors have been investigated which were selected in accordance with the regimes of setting of their crystals. Thermal resistance spectra have been obtained from the analysis of time−dependent dynamic thermal impedance using a new non−destructive method of differential spectroscopy using higher order derivatives (order 3). We present both continuous (integral) and discrete spectra of the distribution of internal thermal resistance in the transistors and the value of the junction/case thermal resistance. Thermal characteristics of the KP723G transistors and their imported counterparts IRLZ44 and IRLB3036 have been determined. The method of determining the active area of devices has been developed and its decrease during heating has been shown. The proposed methodology is useful in solving technological problems of forming the setting layers of crystals and intermediate layers between a crystal and a heat sink and also for the development of thermal models in SPICE modeling of powerful MOSFETs and diode emitters.На основе исследования переходных процессов при саморазогреве прямым током разработан и апробирован эффективный метод определения тепловых параметров мощных полевых транзисторов. С помощью разработанного релаксационного спектрометра тепловых процессов исследованы дифференциальные профили распределения теплового сопротивления транзисторов КП723Г, подобранных в партии в соответствии с режимами посадки их кристаллов на теплоотводящее основание. Спектры тепловых сопротивлений рассчитаны из анализа временной зависимости динамического теплового импеданса новым неразрушающим методом дифференциальной спектроскопии с использованием производных высших порядков (3-го порядка). Представлены как непрерывные (интегральные), так и дискретные спектры распределения внутреннего теплового сопротивления транзисторов, а также значения теплового сопротивления переход—корпус. Определены тепловые характеристики транзисторов КП723Г и их импортных аналогов IRLZ44 и IRLB3036. Развит метод оценки активной площади приборов и установлено ее уменьшение с нагревом. Показано, что предложенные методики полезны при решении технологических проблем формирования слоев посадки кристаллов и создания промежуточных слоев между кристаллом и теплоотводящим основанием, а также для разработки тепловых моделей при SPICE-моделировании мощных полевых транзисторов и диодных излучателей