Use of computers to exclude the influence of radiometer instability upon measurement results

A radiometer, practically insensitive to great fluctuations in the equipment amplification coefficient, was developed by dividing the useful signal by a reference signal and modulating the two signals at different frequencies. The signals are simultaneously separated by corresponding synchronous detectors and recorded over two channels. The operation is simplified by replacing the continuous signals by a sampling of discrete values, and using a digital computer. The four steps involved in the process are described and a block diagram is included. This technique not only directly connects the radiometer with the computer, but also records all data provided by the control and signal channels

Self-consistent approach for the quantum confined Stark effect in shallow quantum wells

A computationally efficient, self-consistent complex scaling approach to calculating characteristics of excitons in an external electric field in quantum wells is introduced. The method allows one to extract the resonance position as well as the field-induced broadening for the exciton resonance. For the case of strong confinement the trial function is represented in factorized form. The corresponding coupled self-consistent equations, which include the effective complex potentials, are obtained. The method is applied to the shallow quantum well. It is shown that in this case the real part of the effective exciton potential is insensitive to changes of external electric field up to the ionization threshold, while the imaginary part has non-analytical field dependence and small for moderate electric fields. This allows one to express the exciton quasi-energy at some field through the renormalized expression for the zero-field bound state.Comment: 13 pages, RevTeX4, 6 figure

Decay modes of two repulsively interacting bosons

We study the decay of two repulsively interacting bosons tunneling through a delta potential barrier by direct numerical solution of the time-dependent Schr\"odinger equation. The solutions are analyzed according to the regions of particle presence: both particles inside the trap (in-in), one particle in and one particle out (in-out), and both particles outside (out-out). It is shown that the in-in probability is dominated by exponential decay, and its decay rate is predicted very well from outgoing boundary conditions. Up to a certain range of interaction strength the decay of in-out probability is dominated by the single particle decay mode. The decay mechanisms are adequately described by simple models.Comment: 18 pages, 13 figure

Conceptual inconsistencies in finite-dimensional quantum and classical mechanics

Utilizing operational dynamic modeling [Phys. Rev. Lett. 109, 190403 (2012); arXiv:1105.4014], we demonstrate that any finite-dimensional representation of quantum and classical dynamics violates the Ehrenfest theorems. Other peculiarities are also revealed, including the nonexistence of the free particle and ambiguity in defining potential forces. Non-Hermitian mechanics is shown to have the same problems. This work compromises a popular belief that finite-dimensional mechanics is a straightforward discretization of the corresponding infinite-dimensional formulation.Comment: 5 pages, 2 figure

ІНФОРМАЦІЙНО-АНАЛІТИЧНА СИСТЕМА ЗАКЛАДІВ ОХОРОНИ ЗДОРОВ'Я "ЕЛЕКТРОННА ЛІКАРНЯ"

Problems of creating a modern information and analytical system for establishments of public health service in Ukraine are considered.It is shown on a concrete example that exactly information is a basis for decision-making in a hospital. Therefore, the automatization of establishment will sure to result in increase of efficiency of its workand, consequently, to improved quality of rendering medical care. The development of information and analytical system "Electronic hospital" was carried out in two stages and the following step of its development should be connected to telemedicine.It is noted, that under new social and economic conditions a weak part in information system in public health service in Ukraine is the absence of authorized integral standards in medical information. The necessity of developing the integral unified medical documentation is emphasized.Рассмотрены проблемы создания современной информационно - аналитической системы для учреждений здравоохранения.Показано на конкретном примере, что именно информация является основой для принятия решений в больнице. Поэтому автоматизация учреждения обязательно приведет к повышению эффективности его работы и, как следствие, - к улучшению качества оказания медицинской помощи. Разработка информационно-аналитической системы «Электронная больница» осуществлялась в два этапа и следующая ступень её развития должна быть связана с телемедициной.Отмечается, что в новых социально - экономических условиях слабым звеном в информатизации системы здравоохранения в Украине является отсутствие утвержденного единого стандарта медицинской информации.Подчеркивается необходимость разработки единой медицинской унифицированной документации.Затронуты также важные вопросы использования международных стандартов обмена информацией.Розглянуті проблеми створення сучасної інформаційно - аналітичної системи для установ охорони здоров'я в Україні.Показано на конкретному прикладі, що саме інформація є основою для прийняття рішень в лікарні. Тому автоматизація установи обов'язково приведе до підвищення ефективності її роботи і, як наслідок, - до поліпшення якості надання медичної допомоги. Розробка інформаційно - аналітичної системи «Електронна лікарня» здійснювалася в два етапи і наступний ступінь її розвитку повинен бути пов'язаний з телемедициною.Наголошується, що в нових соціально - економічних умовах слабкою ланкою в інформатизації системи охорони здоров'я в Україні є відсутність затвердженого єдиного стандарту медичної інформації.Підкреслюється необхідність розробки єдиної медичної уніфікованої документації

Fractal Weyl law for quantum fractal eigenstates

The properties of the resonant Gamow states are studied numerically in the semiclassical limit for the quantum Chirikov standard map with absorption. It is shown that the number of such states is described by the fractal Weyl law and their Husimi distributions closely follow the strange repeller set formed by classical orbits nonescaping in future times. For large matrices the distribution of escape rates converges to a fixed shape profile characterized by a spectral gap related to the classical escape rate.Comment: 4 pages, 5 figs, minor modifications, research at http://www.quantware.ups-tlse.fr

Archaeological supplement B to Damgaard et al. 2018: discussion of the archaeology of Central Asian and East Asian Neolithic to Bronze Age hunter-gatherers and early pastoralists, including consideration of horse domestication

This is the author accepted manuscript. The final version is available from Zenodo via the DOI in this recordThis is part of the additional supplementary material for Damgaard et al., The first horse herders and the impact of early Bronze Age steppe expansions into Asia. Science. DOI: 10.1126/science.aar7711. Note that the author accepted manuscript version of the article plus supplementary material and additional supplementary material is in ORE at http://hdl.handle.net/10871/32791The archaeological evidence relating to selected key cultures from Central and East Asia from the Neolithic to the Bronze Age is summarized. These cultures include the Eneolithic (Copper Age) Botai culture of northern Kazakhstan, the Bronze Age Okunevo culture from the Minusinsk Basin in Russia and Neolithic to Bronze Age cultures of the Baikal Region in East Siberia. Special consideration is given to the debate surrounding horse domestication within the Botai Culture, and the key lines of evidence are summarized

Siegert pseudostates: completeness and time evolution

Within the theory of Siegert pseudostates, it is possible to accurately calculate bound states and resonances. The energy continuum is replaced by a discrete set of states. Many questions of interest in scattering theory can be addressed within the framework of this formalism, thereby avoiding the need to treat the energy continuum. For practical calculations it is important to know whether a certain subset of Siegert pseudostates comprises a basis. This is a nontrivial issue, because of the unusual orthogonality and overcompleteness properties of Siegert pseudostates. Using analytical and numerical arguments, it is shown that the subset of bound states and outgoing Siegert pseudostates forms a basis. Time evolution in the context of Siegert pseudostates is also investigated. From the Mittag-Leffler expansion of the outgoing-wave Green's function, the time-dependent expansion of a wave packet in terms of Siegert pseudostates is derived. In this expression, all Siegert pseudostates--bound, antibound, outgoing, and incoming--are employed. Each of these evolves in time in a nonexponential fashion. Numerical tests underline the accuracy of the method

Anti-de-Sitter Island-Universes from 5D Standing Waves

We construct simple standing wave solutions in a 5D space-time with a ghost scalar field. The nodes of these standing waves are 'islands' of 4D Minkowski space-time. For the 5D model with increasing (decreasing) warp factor there are a finite (infinite) number of nodes and thus Minkowski island-universes having different parameters, such as gravitational and cosmological constants. This feature is similar to the assumptions of the landscape models, which postulate a large number of universes with different parameters. This standing wave solution also provides a new localization mechanism - matter fields can reside only on Minkowski 'islands', where the background space-time does not oscillate.Comment: 14 page pre-print format. Discussion about connection to Weyl gravity added and "E&M" localization method added. To be published MPL

Theory of x-ray absorption by laser-dressed atoms

An ab initio theory is devised for the x-ray photoabsorption cross section of atoms in the field of a moderately intense optical laser (800nm, 10^13 W/cm^2). The laser dresses the core-excited atomic states, which introduces a dependence of the cross section on the angle between the polarization vectors of the two linearly polarized radiation sources. We use the Hartree-Fock-Slater approximation to describe the atomic many-particle problem in conjunction with a nonrelativistic quantum-electrodynamic approach to treat the photon-electron interaction. The continuum wave functions of ejected electrons are treated with a complex absorbing potential that is derived from smooth exterior complex scaling. The solution to the two-color (x-ray plus laser) problem is discussed in terms of a direct diagonalization of the complex symmetric matrix representation of the Hamiltonian. Alternative treatments with time-independent and time-dependent non-Hermitian perturbation theories are presented that exploit the weak interaction strength between x rays and atoms. We apply the theory to study the photoabsorption cross section of krypton atoms near the K edge. A pronounced modification of the cross section is found in the presence of the optical laser.Comment: 13 pages, 3 figures, 1 table, RevTeX4, corrected typoe