January 21st, 2021

лошадь, диаграмма, Фейнман

Обзор экзотических кварковых состояний

Theory Overview of Heavy Exotic Spectroscopy: https://arxiv.org/abs/2101.08241
Ciaran Hughes
This proceeding broadly overviews the current landscape of heavy exotic spectroscopy. Such work includes the composition of certain X, Y , and Z states, and proceeds to discuss tetraquarks made exclusively of four quarks.
Comments: Proceedings For Review Talk at Beauty 2020, 8 pages
лошадь, диаграмма, Фейнман

Резонансы, рассеяние и реакции из первых принципов

Обзорчик на 9 страничек:

Nuclear Resonances, Scattering and Reactions from First Principles: Progress and Prospects: https://arxiv.org/abs/2101.07921
Sofia Quaglioni, Petr Navratil
We present a brief overview of recent developments in ab initio calculations of nuclear scattering and reactions with a focus on applications of the no-core shell model with continuum method.
Comments: 9 pages, 7 figures (one more figure than in the published version)
лошадь, диаграмма, Фейнман

Модележка квантовых задач

Близко к тому, в чем мы ковыряемся...

tRecX -- an environment for solving time-dependent Schrödinger-like problems: https://arxiv.org/abs/2101.08171
Armin Scrinzi
tRecX is a C++ code for solving generalized inhomogeneous time-dependent Schrödinger-type equations idΨ/dt=H[t,Ψ]+Φ in arbitrary dimensions and in a variety of coordinate systems. The operator H[t,Ψ] may have simple non-linearities, as in Gross-Pitaevskii and Hartree(-Fock) problems. Primary application of tRecX has been non-perturbative strong-field single and double photo-electron emission in atomic and molecular physics. The code is designed for large-scale {\it ab initio} calculations, for exploring models, and for advanced teaching in computational physics. Distinctive numerical methods are the time-dependent surface flux method for the computation of single and double emission spectra and exterior complex scaling for absorption. Wave functions and operators are handled by tree-structures with the systematic use of recursion on the coarse-grain level. Numerical, analytic, and grid-based discretizations can be combined and are treated on the same abstract level. Operators are specified in the input using a script language including symbolic algebra. User-friendly in- and output, error safety, and documentation are integrated by design.
лошадь, диаграмма, Фейнман

На редкость подробно расписанная модележка дозы альфа-облучения

По первому впечатлению - хоть бери и воплощай, или студентам предлагай как бакалаврскую работу:))

A mathematical model to describe the alpha dose rate from a UO2 surface: https://arxiv.org/abs/2101.08174
Angus Siberry, David Hambley, Anna Adamska, Ross Springell
A model to determine the dose rate of a planar alpha-emitting surface, has been developed. The approach presented is a computationally efficient mathematical model using stopping range data from the Stopping Ranges of Ions in Matter (SRIM) software. The alpha dose rates as a function of distance from irradiated UO2 spent fuel surfaces were produced for bench-marking with previous modelling attempts. This method is able to replicate a Monte Carlo (MCNPX) study of an irradiated UO2 fuel surface within 0.6 % of the resulting total dose rate and displays a similar dose profile.
лошадь, диаграмма, Фейнман

К терапии тяжелыми ионами

Хорошо все расписано и проиллюстрировано.

Analysis of Bragg Curve Parameters and Lateral Straggle for Proton and Carbon Beams: https://arxiv.org/abs/2101.08023
Fatih Ekinci, Erkan Bostanci, Ozlem Dagli, Mehmet Serdar Guzel
Heavy ions have varying effects on the target. The most important factor in comparing this effect is Linear Energy Transfer (LET). Protons and carbons are heavy ions with high LET. Since these ions lose energy through collisions as they move through the tissue, their range is not long. This loss of energy increases along the way, and the maximum energy loss is reached at the end of the range. This whole process is represented by the Bragg curve. The input dose of the Bragg curve, full width at half maximum (FWHM) value, Bragg peak amplitude and position, and Penumbra thickness are important factors in determining which particle is advantageous in tumor treatment. While heavy ions move through the tissue, small deviations occur in their direction of travel due to Coulomb collisions. These small deviations cause lateral straggle in the dose profile. Lateral straggle is important in determining the type and energy of the particle used in tumor treatments close to critical organs. In our study, when the water phantom of protons and carbon beams with different energies is taken into consideration, the input dose, FWHM value, peak amplitude and position, penumbra thickness and lateral straggle are calculated using the TRIM code and the results are compared with Monte Carlo (MC) simulation. It was found that the proton has an average of 63% more FWHM and 53% more Penumbra than the carbon ion. The carbon ion has an average of 28-45 times greater Bragg peak amplitude at the same Bragg peak location than the proton. It was observed that the proton scattered approximately 70% more in lateral straggle. The difference was found to be around 1.32 mm. In line with all these results, the most commonly used proton and carbon heavy ions in hadron therapy applications were compared.
лошадь, диаграмма, Фейнман

Городские утки

Позавчера по местному ТВ сообщили, что проводился какой-то учет, и в центре города, на реке Везёлке насчитали 250 этих самых уток (а севернее города, в возле Шопино, где есть какие-то незамерзающие родники, к уткам прибился одинокий лебедь!).

Перед Новым годом я ходил их поснимать, большинство из них толклись прямо на парковой дорожке, под ногами у людей:

DSC_5738_утки.jpg © qedqed.iMGSRC.RU

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