Analytic formulae for high harmonic generation

Analytic formulae describing harmonic generation by a weakly bound electron are derived quantum mechanically in the tunneling limit. The formulae confirm the classical three-step model and provide an analytic explanation for oscillatory structures on the harmonic generation plateau

XUV-assisted high-order-harmonic-generation spectroscopy

Using the analytic time-dependent effective range theory, we study two-color high-order harmonic generation (HHG) involving a weak extreme ultraviolet (XUV) pulse and an intense infrared laser field. Our analysis shows that XUV-assisted HHG spectra contain multiple additional plateau structures originating from absorption of one or more XUV photons at the photorecombination step of HHG. We show also that the HHG rate corresponding to the nth plateau can be presented in a factorized form involving the XUV-assisted (multiphoton) photorecombination cross section (PRCS) corresponding to absorption of n XUV photons of energy Ω and emission of a harmonic of energy Ωh. This factorization allows one to extract the PRCS from the HHG spectrum and to retrieve the cross section of the inverse process: the photoionization cross section involving absorption of a single photon of energy Ωh and emission of n XUV photons of frequency Ω. The analytic HHG results are in excellent agreement with numerical solutions of the three-dimensional time-dependent Schrödinger equation

XUV-assisted high-order-harmonic-generation spectroscopy

Using the analytic time-dependent effective range theory, we study two-color high-order harmonic generation (HHG) involving a weak extreme ultraviolet (XUV) pulse and an intense infrared laser field. Our analysis shows that XUV-assisted HHG spectra contain multiple additional plateau structures originating from absorption of one or more XUV photons at the photorecombination step of HHG. We show also that the HHG rate corresponding to the nth plateau can be presented in a factorized form involving the XUV-assisted (multiphoton) photorecombination cross section (PRCS) corresponding to absorption of n XUV photons of energy Ω and emission of a harmonic of energy Ωh. This factorization allows one to extract the PRCS from the HHG spectrum and to retrieve the cross section of the inverse process: the photoionization cross section involving absorption of a single photon of energy Ωh and emission of n XUV photons of frequency Ω. The analytic HHG results are in excellent agreement with numerical solutions of the three-dimensional time-dependent Schrödinger equation

Development and implrmrntation of an interactive lesson with students of a comprehensive school on the topic “Hygienic value of food additives”

The article discusses the topic of nutritional supplements, their importance in human life and use, as well as in what quantities they are found in students' food products and how to distinguish them correctly.В статье рассмотрена тема пищевых добавок, их значение в жизни человека и применение, а также в каких количествах они встречаются в продуктах питания учеников и как правильно их различать

Atomic photoionization experiment by harmonic-generation spectroscopy

Citation: Frolov, M. V., Sarantseva, T. S., Manakov, N. L., Fulfer, K. D., Wilson, B. P., Tross, J., . . . Trallero-Herrero, C. A. (2016). Atomic photoionization experiment by harmonic-generation spectroscopy. Physical Review A, 93(3), 5. doi:10.1103/PhysRevA.93.031403Measurements of the high-order-harmonic generation yield of the argon (Ar) atom driven by a strong elliptically polarized laser field are shown to completely determine the field-free differential photoionization cross section of Ar, i.e., the energy dependence of both the angle-integrated photoionization cross section and the angular distribution asymmetry parameter

Analysis of incidence in the child population of Yekaterinburg in 2021

The aim of the study - to study the structure of morbidity and compare the most significant acute (OD) and chronic diseases (CRD) of the child population among preschool educational institutions, schools and USPO in 4 districts of the city of Yekaterinburg.Цель исследования – изучить структуру заболеваемости и сравнить наиболее значимые острые и хронические заболевания детского населения среди ДОУ, школ и УСПО в 4 районах города Екатеринбург

On the issue of assessing the risk of developing pathology of the bronchopulmonary and cardiovascular systems in workers engaged in obtaining rough copper

The purpose of the study is to study the occupational risks and the risk of developing pathology of the bronchopulmonary and cardiovascular systems of workers of the copper smelting shop, to propose preventive measures.Цель исследования – изучить профессиональные риски и риск развития патологии бронхолёгочной и сердечно-сосудистой системы рабочих медеплавильного цеха, предложить профилактические мероприятия

Exploration of hyperfine interaction between constituent quarks via eta productions

In this work, the different exchange freedom, one gluon, one pion or Goldstone boson, in constituent quark model is investigated, which is responsible to the hyperfine interaction between constituent quarks, via the combined analysis of the eta production processes, $\pi^{-}p\rightarrow\eta n$ and $\gamma p\rightarrow\eta p$. With the Goldstone-boson exchange, as well as the one-gluon or one-pion exchange, both the spectrum and observables, such as, the differential cross section and polarized beam asymmetry, are fitted to the suggested values of Particle Data Group and the experimental data. The first two types of exchange freedoms give acceptable description of the spectrum and observables while the one pion exchange can not describe the observables and spectrum simultaneously, so can be excluded. The experimental data for the two processes considered here strongly support the mixing angles for two lowest S11 sates and D13 states as about -30 and 6 degree respectively.Comment: 7 pages, 4 figures, 4 table

ВЛИЯНИЕ НИКОТИНОВОЙ КИСЛОТЫ НА ВЫЖИВАЕМОСТЬ И НЕЙРОДЕГЕНЕРАЦИЮ В МОЗГЕ ТРАНСГЕННЫХ DROSOPHILA MELANOGASTER С ГИПЕРЭКСПРЕССИЕЙ ГЕНА АРР ЧЕЛОВЕКА

Transgenic Drosophila melanogaster lines modeling the main neuromorphological markers of Alzheimer's disease were used to study the neuroprotective properties of nicotinic acid. Thirty days old flies treated with nicotinic acid showed better survival rate and reduced neurodegeneration.На трансгенных линиях Drosophila melanogaster, воспроизводящих основные нейроморфологические признаки болезни Альцгеймера, исследованы нейропротекторные свойства никотиновой кислоты. Показано, что никотиновая кислота увеличила выживаемость всех исследованных линий и снизила уровень нейродегенерации в мозге 30-дневных мух