Методика расчета ошибок курса при наведении самолета на маневрирующую воздушную цель

The article presents theoretical calculations that explain the origin of errors in the course of an aircraft in an automated control system when pointing at a maneuvering air target. The peculiarity of pointing at a maneuvering target is related to the execution of turns, which are characterized by overloads. The curvature of the trajectory in such areas is usually approximated by a circle of a certain radius, depending on the value of the overload and flight speed to intercept. In the automated control system, the current course of the aircraft is determined as the direction of movement by two marks corresponding to the current and previous moments of information update time. For a target moving in a straight line, this approach is valid. However, in a turn where the guidance path is a curved line, the true heading will correspond to the tangent at the turn point. The difference in these approaches determines the error of the course calculation. This article provides a formulaic calculation of turn radii for flight speeds to intercept an air target and overloads, as well as the calculation of true and current courses. The peculiarity of the methodology is a strict formalized mathematical description. The article presents the dependences of heading errors from the aircraft’s intercept flight speed and overloads using the example of the Su-27 multifunctional fighter.Представлены теоретические расчеты, поясняющие происхождение ошибок расчета курса самолета в автоматизированной системе управления при наведении его на маневрирующую воздушную цель. Особенностью наведения на маневрирующую цель является выполнение виражей, для которых характерны перегрузки. Кривизну траектории на таких участках принято аппроксимировать окружностью определенного радиуса, зависящего от величины перегрузки и скорости полета на перехват. В автоматизированной системе управления текущий курс летательного аппарата определяется как направление движения по двум отметкам, соответствующим текущему и предыдущему моментам времени обновления информации. Для цели, движущейся прямолинейно, такой подход справедлив. Однако при совершении виража, когда траектория наведения есть кривая линия, истинный курс будет соответствовать касательной в точке виража. Разница этих подходов определяет ошибку вычисления курса. В статье приведен формульный расчет радиусов виражей для скоростей полета на перехват воздушной цели и перегрузок, а также расчет истинного и текущего курсов. Особенность методики состоит в строгом формализованном математическом описании. Приведены зависимости ошибок по курсу от скорости полета самолета на перехват и перегрузок на примере многофункционального истребителя Су-27

Picosecond Fluorescence Relaxation Spectroscopy of the Calcium-Discharged Photoproteins Aequorin and Obelin

Addition of calcium ions to the Ca2+-regulated photoproteins, such as aequorin and obelin, produces a blue bioluminescence originating from a fluorescence transition of the protein-bound product, coelenteramide. The kinetics of several transient fluorescent species of the bound coelenteramide is resolved after picosecond-laser excitation and streak camera detection. The initially formed spectral distributions at picosecond-times are broad, evidently comprised of two contributions, one at higher energy (25000 cm-1) assigned as from the Ca2+-discharged photoprotein-bound coelenteramide in its neutral state. This component decays much more rapidly (t1/2 2 ps) in the case of the Ca2+-discharged obelin than aequorin (t1/2 30 ps). The second component at lower energy shows several intermediates in the 150-500 ps times, with a final species having spectral maxima 19400 cm-1, bound to Ca2+-discharged obelin, and 21300 cm-1, bound to Ca2+-discharged aequorin, and both have a fluorescence decay lifetime of 4 ns. It is proposed that the rapid kinetics of these fluorescence transients on the picosecond time scale, correspond to times for relaxation of the protein structural environment of the binding cavit

СТРУКТУРА И ЭЛЕМЕНТНЫЙ СОСТАВ АНОДНЫХ АЛЮМООКСИДНЫХ ПЛЕНОК, СФОРМИРОВАННЫХ В СЕРНОКИСЛОМ ЭЛЕКТРОЛИТЕ ВЫСОКОЙ КОНЦЕНТРАЦИИ

Porous aluminium anodization process has been investigated in 63 wt % sulfuric electrolyte. Porous alumina formed at anodic voltages till 16 V had the «honey comb» cell structure while porous alumina formed at anodic voltages more than 16 V displayed the tubular cell structure with thickness expansion factor more than 2,5. The obtained results can be explained by resulted of Al(OH)3 formation during anodization process at high electric field inside anodic films.Представлены результаты исследования электрохимического анодирования алюминиевой фольги и тонких алюминиевых пленок, осажденных на кремниевые пластины, в сернокислом электролите высокой концентрации при разных напряжениях формовки. Показано, что при увеличении напряжения формовки более 16 В происходит формирование трубчатой структуры анодного оксида, большую часть которого составляет гидрооксид алюминия. При этом коэффициент роста толщины анодных пленок увеличивается до 3, а коэффициент формовки гексагональных ячеек снижается до 2,2 нм/В

Structure and element composition of anodic alumina films formed in high concentrated sulfuric electrolyte

Porous aluminium anodization process has been investigated in 63 wt % sulfuric electrolyte. Porous alumina formed at anodic voltages till 16 V had the «honey comb» cell structure while porous alumina formed at anodic voltages more than 16 V displayed the tubular cell structure with thickness expansion factor more than 2,5. The obtained results can be explained by resulted of Al(OH)3 formation during anodization process at high electric field inside anodic films

Unanimous Model for Describing the Fast Bioluminescence Kinetics of Ca²⁺-regulated Photoproteins of Different Organisms

Upon binding their metal ion cofactors, Ca2+-regulated photoproteins display a rapid increase of light signal, which reaches its peak within milliseconds. In the present study, we investigate bioluminescence kinetics of the entire photoprotein family. All five recombinant hydromedusan Ca2+-regulated photoproteins-aequorin from Aequorea victoria, clytin from Clytia gregaria, mitrocomin from Mitrocoma cellularia and obelins from Obelia longissima and Obelia geniculata-demonstrate the same bioluminescent kinetics pattern. Based on these findings, for the first time we propose a unanimous kinetic model describing the bioluminescence mechanism of Ca2+-regulated photoproteins

The mathematical model of heading channel autonomous system of aircraft landing on unequipped airfields by trajectory guiding

У роботі розроблено детерміновану математичну модель каналу курсу автономної системи траєкторного управління посадкою літаків на необладнані аеродром. Управління курсом ЛА здійснюється шляхом застосування режиму плоского розвороту.В работе разработана детерминированная математическая модель канала курса автономной системы траекторного управления посадкой самолетов на необорудованные аэродром. Управление курсом ЛА осуществляется путем применения режима плоского разворота.In this work is developed determinate mathematical model of heading channel autonomous system of aircraft landing on unequipped airfields by trajectory guiding. The guiding of aircraft implement by surface turn mode

The Role of Tyr-His-Trp Triad and Water Molecule Near the N1-Atom of 2-Hydroperoxycoelenterazine in Bioluminescence of Hydromedusan Photoproteins: Structural and Mutagenesis Study

Hydromedusan photoproteins responsible for the bioluminescence of a variety of marine jellyfish and hydroids are a unique biochemical system recognized as a stable enzyme-substrate complex consisting of apoprotein and preoxygenated coelenterazine, which is tightly bound in the protein inner cavity. The binding of calcium ions to the photoprotein molecule is only required to initiate the light emission reaction. Although numerous experimental and theoretical studies on the bioluminescence of these photoproteins were performed, many features of their functioning are yet unclear. In particular, which ionic state of dioxetanone intermediate decomposes to yield a coelenteramide in an excited state and the role of the water molecule residing in a proximity to the N1 atom of 2-hydroperoxycoelenterazine in the bioluminescence reaction are still under discussion. With the aim to elucidate the function of this water molecule as well as to pinpoint the amino acid residues presumably involved in the protonation of the primarily formed dioxetanone anion, we constructed a set of single and double obelin and aequorin mutants with substitutions of His, Trp, Tyr, and Ser to residues with different properties of side chains and investigated their bioluminescence properties (specific activity, bioluminescence spectra, stopped-flow kinetics, and fluorescence spectra of Ca2+-discharged photoproteins). Moreover, we determined the spatial structure of the obelin mutant with a substitution of His64, the key residue of the presumable proton transfer, to Phe. On the ground of the bioluminescence properties of the obelin and aequorin mutants as well as the spatial structures of the obelin mutants with the replacements of His64 and Tyr138, the conclusion was made that, in fact, His residue of the Tyr-His-Trp triad and the water molecule perform the “catalytic function” by transferring the proton from solvent to the dioxetanone anion to generate its neutral ionic state in complex with water, as only the decomposition of this form of dioxetanone can provide the highest light output in the light-emitting reaction of the hydromedusan photoproteins