Издательство: Учпедгиз
Год выпуска: 1957
Количество страниц: 108 с.
Киренский, Леонид Васильевич.
Ферромагнетизм и его применение. - Москва : Учпедгиз, 1957. - 104 с.
Количество страниц: 6 с.
The paper considers the problem of the noise impact of the CHP operation on adjacent settlements and on humans. At power generating facilities, the process of steam discharge from boilers is a powerful source of noise. This process occurs in emergency situations in order to reduce pressure and during kindling. When discharged from boilers through the GPC, an under expanded and non-isothermal steam flow with high speed, pressure and temperature emits a noise equivalent in characteristics to the sound of a jet engine. To perform the calculations, a request was made for data on steam parameters in front of the GPC from the Vyborgskaya CHP - 17 station, part of the TGC-1 power generating company in St. Petersburg. The calculation of the maximum value of the sound pressure of steam discharge from boilers was carried out. Sound pressure levels have been determined at various octave levels with average geometric frequencies in the range from 31.5 to 8000 Hz. A graph of the dependence of the sound pressure level on the octave level is constructed. It was revealed that the noise of steam discharge has a high-frequency character, the extreme value occurs at a frequency of 1000 Hz and is equal to 161.3 dB for boilers No. 4, 5, 6 and 158.7 dB for boilers No. 1, 2, 3. For comparison, the sound pressure level of the noise of an aircraft jet engine is approximately 160 db. To reduce the harmful effects of noise on humans and adjacent populated areas near the station, it is recommended to install special extinguishing agents - silencers.
Реев, В. Г. Расчет максимального звукового давления выброса пара из котлоагрегата ТЭЦ / В. Г. Реев, У. Д. С. Гунасекара ; Северо-Восточный федеральный университет им. М. К. Аммосова, Санкт-Петербургский политехнический университет Петра Великого // Вестник Северо-Восточного федерального университета им. М. К. Аммосова. - 2024. - Т. 21, N 2 (96). - С. 71-76. - DOI: 10.25587/2222-5404-2024-21-2-71-76
DOI: 10.25587/2222-5404-2024-21-2-71-76
Количество страниц: 9 с.
The high latitude ionospheric plasma is a difficult medium to describe due to the dependence of its parameters on heliogeophysical conditions. Its large-scale structure is influenced by processes such as magnetospheric convection, plasmaspheric flows of particles and heat, as well as the precipitation of energetic particles in the region of the auroral oval. These processes are non-stationary and their characteristics change significantly during periods of enhanced geomagnetic activity. Therefore, the modelling of the high-latitude ionosphere is associated with the development of a model that has a computationally stable numerical solution at a sufficiently high spatio-temporal resolution. For this purpose, in this work, we have carried out a study of the computational stability of the mathematical model of the high-latitude ionosphere (Eulerian approach) when different integration steps in time and space are specified. It is shown that the ionospheric model retains computational stability at all selected steps, and the results of numerical calculations are qualitatively consistence and describe the main large-scale structural formations of the high-latitude ionosphere. The results show that the developed model can be used in the study of non-stationary processes occurring in the ionospheric plasma, as well as in the study of the ionosphere during magnetic storms and substorms.
Гололобов, А. Ю. Исследование вычислительной устойчивости модели высокоширотной ионосферы / А. Ю. Гололобов, И. А. Голиков ; Институт космофизических исследований и аэрономии им. Ю. Г. Шафера // Вестник Северо-Восточного федерального университета им. М. К. Аммосова. - 2024. - Т. 21, N 2 (96). - С. 37-45. - DOI: 10.25587/2222-5404-2024-21-2-37-45
DOI: 10.25587/2222-5404-2024-21-2-37-45
Количество страниц: 11 с.
Currently, the use of electron microscopes in medicine is developing intensively, including scanning electron microscopes (SEM), which are designed to solve a huge number of problems in various fields with a wide range of electron accelerating voltages and electron beam energies. The development of an SEM with certain emission characteristics, with a range of lower beam energies for the study of biological samples, is an urgent task because modifying the SEM to solve problems in medicine, for example, would make it possible to obtain higher-quality images of biospecimens for diagnostics and monitoring the effectiveness of therapy. To develop new SEMs with certain characteristics, it is proposed to conduct less expensive research using numerical methods based on mathematical models of processes in electron-optical SEM systems. In this regard, this work sets the task of determining the size and shape of the beam, the main emission characteristics of the field electron cathode (FEC) of the SEM, which is under the influence of the electric field that excites electron emission and the external longitudinal magnetic field by studying the movement of the outermost electron of the beam, taking into account the influence of space charge beam electrons, external magnetic field. In the model, the FEC is approximated by a paraboloid of rotation, and the concept of a boundary “outermost” electron is introduced, the trajectory of which determines the shape and size of the beam. The problem of calculating the emission characteristics along the trajectory of the outermost electron of a FEC is solved using a mathematical model that includes the following equations: motion of the "outermost" electron, Maxwell outside and inside the beam, continuity of the current density, Fowler-Nordheim equation. As a result, a system of 18 first-order ordinary differential equations was obtained, the numerical calculation of which using the 4th order Runge-Kutta method allows us to obtain the emission characteristics of the FEC. As a result, it is suggested that it would be feasible to modify SEMs for more effective use in the medical field, taking into account their increasing use in disease diagnosis and the possible improvement of image quality through the development of FEC SEMs with more suitable characteristics.
Математическое моделирование эмиссионных характеристик полевого электронного катода в растровом электронном микроскопе в условиях исследования биообразцов / С. Н. Мамаева, Н. В. Егоров, Б. В. Яковлев [и др.] ; Северо-Восточный федеральный университет им. М. К. Аммосова, Санкт-Петербургский государственный университет, Московский государственный университет имени М. В. Ломоносова // Вестник Северо-Восточного федерального университета им. М. К. Аммосова. - 2024. - Т. 21, N 1 (95). - С. 70-80. - DOI: 10.25587/2222-5404-2024-21-1-70-80
DOI: 10.25587/2222-5404-2024-21-1-70-80
Количество страниц: 13 с.
The interplanetary magnetic field (IMF), frozen into the solar wind plasma, determines the level of geomagnetic activity and significantly affects the large-scale structure of the high-latitude ionosphere. Variations in the IMF components lead to non-stationarity of the magnetospheric convection electric field, causing changes in the spatio-temporal distribution of charged particles in the ionosphere. The situation is complicated by the fact that the geographic and geomagnetic poles do not coincide, which leads to universal time control (UT control) of the parameters of the high-latitude ionosphere. The effect of the poles displacement is most manifest in winter. Therefore, in this work, within the framework of a nonstationary mathematical model of the F-region of the ionosphere in Euler variables, taking into account the displacement between the geographic and geomagnetic poles, we study the influence of the interplanetary magnetic field components on the large-scale structure of the high-latitude ionosphere in winter. For this, the Weimer model of high-latitude electric potentials, which depends on the IMF, was used. As a result, of numerical modelling, it is shown that the IMF components affect the shape, size and spatio-temporal location of the main structural features of the high-latitude ionosphere depending on universal time. The obtained effect of ionisation tongue separation requires experimental confirmation. The obtained results demonstrate that the developed non-stationary three-dimensional model of the ionosphere in Euler variables can be applied to the study of ionospheric disturbances, including ionospheric disturbances associated with changes in the IMF components.
Гололобов, А. Ю. Численное моделирование влияния ММП на крупномасштабную структуру ионосферы с учетом несовпадения полюсов / А. Ю. Гололобов, И. А. Голиков ; Институт космофизических исследований иаэрономии им. Ю. Г. Шафера // Вестник Северо-Восточного федерального университета им. М. К. Аммосова. - 2024. - Т. 21, N 1 (95). - С. 45-57. - DOI: 10.25587/2222-5404-2024-21-1-45-57
DOI: 10.25587/2222-5404-2024-21-1-45-57
Количество страниц: 12 с.
This work reports on the methods developed by our group at ShICRA SB RAS to forecast negative manifestations of space weather from ground-based measurements of cosmic rays. Such manifestations are registered on the Earth in the form of decreases in galactic cosmic rays known as the Forbush effects, various types of geomagnetic and ionospheric disturbances, as well as auroras. Only the latters are directly visible to the naked eye, while the rest can only be detected with the help of various instruments. These occurrences are all caused by passage through the Earth’s orbit, such as the substantial influxes of charged particles from both solar and interplanetary sources, interplanetary shock waves, ejections of solar material and high-speed solar wind streams, all of which are attributed to the level of solar flares and coronal activity. The state of near-Earth space weather is determined by their presence. To monitor this state, we use data collected from ground-based cosmic ray stations and employ multiple methods to analyse these measurements. Additionally, we incorporate data from the Dst-index of the geomagnetic field and measurements of the interplanetary environmental parameters gathered by ACE, WIND, SOHO and DSCOVR spacecraft at the L1 libration point to confirm events. This has led to the development of techniques for predicting terrestrial effects of space weather in the short-term (1-3 days). Our findings suggest that it is feasible to predict the occurrence of severe geomagnetic storms in real-time through the utilisation of solely ground-based measurements from cosmic ray stations.
Прогноз возмущений солнечного ветра и геомагнитных бурь на основе наземных измерений космических лучей / А. С. Зверев, П. Ю. Гололобов, В. Г. Григорьев [и др.] ; Институт космофизических исследований и аэрономии им. Ю. Г. Шафера // Вестник Северо-Восточного федерального университета им. М. К. Аммосова. - 2024. - Т. 21, N 1 (95). - С. 58-69. - DOI: 10.25587/2222-5404-2024-21-1-58-69
DOI: 10.25587/2222-5404-2024-21-1-58-69
Количество страниц: 8 с.
The paper presents the results of a study on the search for correct methods for measuring a high-value current pulse, which will be used to conduct research on the electroplastic effect. The electroplastic effect is the effect of electric current pulses on the plastic flow of metals. Electroplastic metal forming technology is a relatively new metal forming process that is energy efficient, environmentally friendly and versatile. In particular, it can be used to process metals or alloys that are difficult to process using conventional manufacturing processes. For the experimental study of the electroplastic effect, it became necessary to measure pulse currents of large magnitude, not only in amplitude, but also in the shape of the pulse. The pulsed current causes the formation of an alternating electromagnetic field near the conductors, so it can be measured with a Rogovsky current transformer. The results of the work present a schematic electrical diagram and a photograph with the appearance of an experimental installation for the study of the electroplastic effect. The results of measurements of the current value, the voltage drop on the sample and the dependence of the peak voltage values on the sample on the peak current value are shown. After making calculations and renormalising the data for the voltage drop on the sample according to the peak value of the current obtained on the transformer, the authors obtained the desired current values. The error of this method is estimated by calculating the total capacitance of capacitors, which does not exceed 2%.
Разработка способа измерения импульсных токов большой величины / В. П. Татаринов, П. С. Татаринов, Ю. В. Бебихов [и др.] ; Северо-Восточный федеральный университет им. М. К. Аммосова, Политехнический институт (филиал), Институт физики молекул и кристаллов УФИЦ, Институт проблем сверхпластичности металлов // Вестник Северо-Восточного федерального университета им. М. К. Аммосова. - 2024. - Т. 21, N 1 (95). - С. 81-88. - DOI: 10.25587/2222-5404-2024-21-1-81-88
DOI: 10.25587/2222-5404-2024-21-1-81-88
Количество страниц: 9 с.
The evaluation of heat input through fences is an important part of the task of predicting the summer thermal regime of a building under a transparent dome, the interest in the construction of which in the northern regions has increased recently. The calculation of the summer thermal regime of a building under a dome is complicated by taking into account the greenhouse effect, which requires solving the problem of radiative heat transfer in the system: opaque wall - semitransparent screen - environment. It is also necessary to take into account the convection in the dome space. А relatively simple model for calculating the characteristics of heat transfer through the wall of a building with a dome, which takes into account the greenhouse effect, is considered in this paper. Comparison of calculations with experimental data allows us to speak about the adequacy of the proposed model. It is shown that the presence of semitransparent screen due to the greenhouse effect leads to a significant raise in temperature under the dome and an increase in heat input into the building. The influence of ventilation in the dome space on heat access through the enclosing structure for the selected values of external parameters: external temperature and solar radiation was evaluated. The proposed model of heat transfer through the enclosing structure with a semitransparent screen can become part of a more complete model for calculating the thermal regime of a building under a dome.
Тимофеев, А. М. Влияние парникового эффекта на теплопередачу через ограждающие конструкции здания / А. М. Тимофеев, Д. В. Харюзов ; Северо-Восточный федеральный университет им. М. К. Аммосова // Вестник Северо-Восточного федерального университета им. М. К. Аммосова. - 2024. - Т. 21, N 1 (95). - С. 89-97. - DOI: 10.25587/2222-5404-2024-21-1-89-97
DOI: 10.25587/2222-5404-2024-21-1-89-97
Ответственность: Геннадиник Б. И. (Редактор)
Издательство: Наука. Сибирское отделение
Год выпуска: 1977
Количество страниц: 116 с.
- Институт мерзлотоведения им. П.И. Мельникова СО РАН > Публикации,
- Математика. Естественные науки > Физика,
- Математика. Естественные науки > Общая геология . Метеорология. Климатология. Историческая геология. Стратиграфия. Палеогеография,
- НАУКА ЯКУТИИ > МАТЕМАТИКА. ЕСТЕСТВЕННЫЕ НАУКИ > Геология. Геологические и геофизические науки,
- НАУКА ЯКУТИИ > МАТЕМАТИКА. ЕСТЕСТВЕННЫЕ НАУКИ > Физика.
Мельников, Владимир Павлович.
Электрофизические исследования мерзлых пород : (методология и практика) / В. П. Мельников ; ответственный редактор Б. И. Геннадиник ; Академия наук СССР, Сибирское отделение, Институт мерзлотоведения. - Якутск : Наука. Сибирское отделение, 1977. - 108 с., [2] л. ил.
Количество страниц: 4 с.
- Общественные науки. Образование > Народное образование. Воспитание. Обучение. Организация досуга > Общеобразовательная школа. Дошкольные учреждения,
- Математика. Естественные науки > Физика,
- НАУКА ЯКУТИИ > ОБЩЕСТВЕННЫЕ НАУКИ > Народное образование. Воспитание. Обучение. Организация досуга > Общеобразовательная школа. Дошкольные учреждения,
- НАУКА ЯКУТИИ > МАТЕМАТИКА. ЕСТЕСТВЕННЫЕ НАУКИ > Физика.
The article contains examples of integratedand creative tasks developed on the basis of the regionalcomponent and contributing to the formation of functionalliteracy. Tasks help students develop the skills to use natural science knowledge to understand physical processesand phenomena in the world around them.
Маркова, И. В. Национально-региональный компонент как основа формирования функциональной грамотности на уроках физики / И. В. Маркова ; МБОУ "Средняя общеобразовательная школа N 22" // Народное образование Якутии. - 2023. - N 1 (126). - С. 49-52.