Photon assisted tunneling in pairs of silicon donors

Shallow donors in silicon are favorable candidates for the implementation of solid-state quantum computer architectures because of the promising combination of atomiclike coherence properties and scalability from the semiconductor manufacturing industry. Quantum processing schemes require (among other things) controlled information transfer for readout. Here we demonstrate controlled electron tunneling at 10 K from P to Sb impurities and vice versa with the assistance of resonant terahertz photons

ВИДОВИЙ СКЛАД ТА СТАН РАРИТЕТНИХ ДЕНДРОЕКЗОТІВ ВІДДІЛУ PINOPHYTA БОТАНІЧНОГО САДУ ЧЕРНІВЕЦЬКОГО НАЦІОНАЛЬНОГО УНІВЕРСИТЕТУ ІМЕНІ ЮРІЯ ФЕДЬКОВИЧА

An effective direction of rare exotic plant species preservation is their ex situ cultivation conditions that is realized for introduced plants in botanical gardens, dendrological parks and other preserved parks. Lately, first actions for preservation rare woody plants in ex situ conditions in Ukraine are inventory research, elucidation of their spreading in cultivated area, their conservation status due to the Red Lists of international significance (such as The IUСN Red List of Threatened Species) and estimation of their adaptation level. Therefore, the purpose of our research is to analyze species composition, conservation status due to The IUСN Red List of Threatened Species, geographical origin, taxation parameters, winter resistance and generative development of Pinophyta rare woody exotic plants cultivated in Chernivtsi National University Botanical Garden. At the beginning of 2018, 39 species of rare dendroexotic plants of Pinophyta are growing in the open ground conditions in Botanical Garden. They belong to 20 genus, 4 families. The authors have ascertained that 19 species originated in East Asia and 14 species are from North America. 51. 3 % of species are endemics and 3 species are relicts. All species are recorded in The Red List of Threatened Species and are distributed by 5 categories; species from LC category are predominated (26 species). According to The IUCN Red List, all species that belong to EN (Endangered) and CR (Critically Endangered) categories and 4 species of NT (Near Threatened) category are endemics, so they need special conservation actions. 33 species are trees (29 among them are trees of first magnitude) and 3 species are shrubs. All species retain the growth form, while 7 species have reached the typical height for them. 35 species are revealed to be completely winter-hardly. 22 species form seeds and 5 species are self-propagated. Thus, Pinophyta rare woody exotic plants of Chernivtsi National University Botanical Garden are valuable as a reserve of genetic material and plants in the scientific and educational meaning. Trees of 10 species that have a special historical, collectible and scientific value are pointed out; they are from 110 to above 140 years old. Investigated plants have also forestry, meliorative, decorative and medicinal value. Further successful preservation of these species in the Pre-Carpathian region will be possible if their resistance to biotic factors, ecological and coenotic peculiarities is studied.Наведено результати аналізу видового складу, географічного походження, таксаційних показників, зимостійкості, здатності до генеративного розвитку та розподілу за категоріями раритетності згідно до Червоним списком МСОП деревних інтродуцентів відділу Pinophyta ботанічного саду Чернівецького національного університету ім. Юрія Федьковича. З'ясовано, що в умовах відкритого ґрунту Саду зростає 39 видів раритетних дендроекзотів відділу Pinophyta із 20 родів, 4 родин. Проведено розподіл за категоріями раритетності відповідно до критеріїв Червоного списку МСОП і показано, що 66,7 % досліджуваних видів належить до таких, які перебуває під невеликою загрозою (категорія LC). Природоохоронний статус 17,9 % видів відповідає категоріям CR, EN і VU. За географічним походженням, домінують представники Східної Азії (19 видів) та Північної Америки (14 видів); ендемічними є 51,3 % видів. Установлено, що в умовах Саду всі види зберігають притаманну їм форму росту, при цьому 7 видів досягли характерної для них висоти. Абсолютно зимостійкими в умовах ботанічного саду є 35 видів; формують насіння – 22 види, з них розмножуються самосівом 5 видів. Виділено представників, які мають особливу історичну, колекційну і наукову цінність. Подальшому успішному збереженню досліджуваних видів в умовах Передкарпаття сприятимуть вивчення їхньої стійкості до біотичних факторів та з'ясування еколого-ценотичних особливостей

Indeterminacy and instability in Petschek reconnection

We explain two puzzling aspects of Petschek's model for fast reconnection. One is its failure to occur in plasma simulations with uniform resistivity. The other is its inability to provide anything more than an upper limit for the reconnection rate. We have found that previously published analytical solutions based on Petschek's model are structurally unstable if the electrical resistivity is uniform. The structural instability is associated with the presence of an essential singularity at the X-line that is unphysical. By requiring that such a singularity does not exist, we obtain a formula that predicts a specific rate of reconnection. For uniform resistivity, reconnection can only occur at the slow, Sweet-Parker rate. For nonuniform resistivity, reconnection can occur at a much faster rate provided that the resistivity profile is not too flat near the X-line. If this condition is satisfied, then the scale length of the nonuniformity determines the reconnection rate

On the Evolution of Ion Bunch Profile in the Presence of Longitudinal Coherent Electron Cooling

In the presence of longitudinal coherent electron cooling, the evolution of the line-density profile of a circulating ion bunch can be described by the 1-D Fokker-Planck equation. We show that, in the absence of diffusion, the 1-D equation can be solved analytically for certain dependence of cooling force on the synchrotron amplitude. For more general cases with arbitrary diffusion, we solved the 1-D Fokker-Planck equation numerically and the numerical solutions have been compared with results from macro-particle tracking

Дендросозофіти ботанічного саду Чернівецького національного університету імені Юрія Федьковича

Collection of information about specific composition, distribution and state of cultivated rare arboreous plants is an important step in creation of conservation measures for these species ex-situ condition. But such information for Chernivtsi region outlined only partially. So, the purpose of our research was to analyze specific composition, their conservation status due to The IUСN Red List of Threatened Species and to evaluate the acclimatization degree of rare aboriginal and introduced arboreous plants cultivated in the Chernivtsi National University Botanic Garden. Conservation status of these species we determined due to The IUСN Red List of Threatened Species, European Red List of Vascular Plants and Red Data Book of Ukraine (2009). Estimation of acclimatization degree, accordingly to M. A. Kochno scale, includes growth, generative development, winter and drought resistance. To the beginning of 2019, 211 species of arboreous plants are growing in the open ground conditions in the Chernivtsi National University Botanic Garden. They are from 87 genus 37 families 2 orders. All species are recorded to The IUCN Red List of Threatened Species and are distributed by 6 categories: 5 of them – to the category CR, 11 species – to EN, 4 – to VU, 9 – to NT, 166 – to LC and 15 species – to the DD category. In the European Red List of Vascular Plants we found 9 species and in the Red Data Book of Ukraine – 7 species. 192 species adapted to the conditions of cultivation completely, and therefore have a higher degree of acclimatization (I). 16 species adapted to cultivation conditions slightly (degree of acclimatization is II), and the degree of acclimatization of 3 species (Diospyros lotus L., Laurocerasus officinalis Roem., Ilex aquifolium L.) varies depending on winter conditions. 174 species in the Botanic Garden form a viable seed. The rest of the species do not fructify because of their young age (11 species), cultivation under the inappropriate ecological conditions (13 species), flowering in the autumn-winter period (Hamamelis virginiana L.). The dioecious species, which are represented only by the male in the Botanic Garden, do not form seeds too. Non-viable seeds form Taxodium distichum (L.) Rich. and Sequoiadendron giganteum Lindl. Consequently, from a group of threatened species (category CR, EN, VU) does not form seeds only 1 of them. High adaptive parameters and the ability to seed reproduction of the majority of investigated species indicate that the collections of the Chernivtsi National University Botanic Garden have high potential for the effective conservation ex-situ of rare arboreous plants.Встановлено, що у ботанічному саду Чернівецького національного університету в умовах відкритого ґрунту зростає 211 видів дендросозофітів із 87 родів, 37 родин, 2 відділів. Серед них із відділу Pinophyta провідними за кількістю видів є роди Pinus L., Abies Mill., Picea Dietr., Juniperus L., а із Magnoliophyta – Rhododendron L., Magnolia L., Acer L., Quercus L., Malus Mill. У Червоному списку МСОП досліджувані види віднесено до 6 категорій раритетності; з них переважає група таксонів з низьким рівнем ризику зникнення (82,9 % видів). До групи під загрозою зникнення (категорії CR, EN, VU) входить 20 видів. До Європейського Червоного списку внесено 9 із досліджуваних видів. 7 видів внесено до Червоної книги України (2009), а Syringa josіkaea – також до Додатку І Бернської конвенції. Показано, що в умовах ботанічного саду Чернівецького національного університету 174 із досліджуваних дендросозофітів формують життєздатне насіння, а у 42 із них відзначено самосів. Виявлено, що 192 види повністю пристосувалися до умов культивування і мають найвищий ступінь акліматизації (І). Виділено види, які в Чернівецькій області стали інвазійними (Robinia pseudoacacia L., Acer negundo L., Quercus rubra L.), а також типові для Буковини види; всі вони мають категорію LC у Червоному списку МСОП. Успішна акліматизація та здатність до насіннєвого розмноження більшості видів свідчать про те, що колекційні фонди ботанічного саду Чернівецького національного університету є потенціалом для ефективного збереження дендросозофітів ex-situ

Charge and matter distributions and form factors of light, medium and heavy neutron-rich nuclei

Results of charge form factors calculations for several unstable neutron-rich isotopes of light, medium and heavy nuclei (He, Li, Ni, Kr, Sn) are presented and compared to those of stable isotopes in the same isotopic chain. For the lighter isotopes (He and Li) the proton and neutron densities are obtained within a microscopic large-scale shell-model, while for heavier ones Ni, Kr and Sn the densities are calculated in deformed self-consistent mean-field Skyrme HF+BCS method. We also compare proton densities to matter densities together with their rms radii and diffuseness parameter values. Whenever possible comparison of form factors, densities and rms radii with available experimental data is also performed. Calculations of form factors are carried out both in plane wave Born approximation (PWBA) and in distorted wave Born approximation (DWBA). These form factors are suggested as predictions for the future experiments on the electron-radioactive beam colliders where the effect of the neutron halo or skin on the proton distributions in exotic nuclei is planned to be studied and thereby the various theoretical models of exotic nuclei will be tested.Comment: 26 pages, 11 figures, 3 tables, accepted for publication in Phys. Rev.

Avaliação dos aspectos financeiros das pequenas e médias empresas: experiência russa

The aim of this study was to assess the key financials of an array of micro-sized businesses, small and medium-sized enterprises as grouped by industry. This article deals with the assessment results of such financials as the net financial result of enterprises, the proportion of profitable and loss-making enterprises, the profitability of manufactured and sold products, the current levels of profit and loss, respectively, per profitable and loss-making enterprise. The dynamics of such financials during the period from 2010 to 2014 was presented. Accounting and statistical reporting was used as the input data. In the course of this research it was proven that during that period the profitable enterprises accounted for about 80%. However, the level of profitability did not depend on the size of an enterprise. The largest proportion of profitable enterprises was noted in such sectors as education and commerce. The net financial result per employee in micro-enterprises was significantly higher than those for medium-sized enterprises and small enterprises. The results of this study may be used to validate business development plans and programs for various regions and sectors of the Russian economy. El objetivo de este estudio fue evaluar las finanzas clave de una serie de pequeñas empresas, pequeñas y medianas empresas agrupadas por industria. Este artículo trata de los resultados de la evaluación de tales finanzas como el resultado financiero neto de las empresas, la proporción de empresas rentables y que generan pérdidas, la rentabilidad de los productos fabricados y vendidos, los niveles actuales de ganancias y pérdidas, respectivamente, por rentabilidad y pérdida empresa de creación. La dinámica de tales finanzas durante el período 2010-2014 se presentó. Los informes contables y estadísticos se usaron como datos de entrada. En el curso de esta investigación, se comprobó que durante ese período las empresas rentables representaron aproximadamente el 80%. Sin embargo, el nivel de rentabilidad no depende del tamaño de una empresa. La mayor proporción de empresas rentables se observó en sectores como la educación y el comercio. El resultado financiero neto por empleado en las microempresas fue significativamente mayor que el de las medianas y pequeñas empresas. Los resultados de este estudio pueden usarse para validar planes y programas de desarrollo comercial para diversas regiones y sectores de la economía rusa. O objetivo deste estudo foi avaliar as principais finanças de uma série de microempresas, pequenas e médias empresas agrupadas por setor. Este artigo trata dos resultados da avaliação de tais finanças como o resultado financeiro líquido das empresas, a proporção de empresas lucrativas e deficitárias, a rentabilidade dos produtos fabricados e vendidos, os níveis atuais de lucros e perdas, respectivamente, por lucro e perda empresa de fabricação. A dinâmica de tais finanças durante o período de 2010 a 2014 foi apresentada. Relatórios contábeis e estatísticos foram usados como dados de entrada. No decorrer desta pesquisa, ficou provado que, durante esse período, as empresas lucrativas representavam cerca de 80%. No entanto, o nível de lucratividade não dependia do tamanho de uma empresa. A maior proporção de empresas lucrativas foi observada em setores como educação e comércio. O resultado financeiro líquido por empregado nas microempresas foi significativamente superior ao das médias empresas e pequenas empresas. Os resultados deste estudo podem ser usados para validar planos e programas de desenvolvimento de negócios para várias regiões e setores da economia russa

Effects of e-beam parameters on coherent electron cooling

Coherent Electron Cooling (CeC) requires detailed control of the phase between the hadron an the FEL-amplified wave packet. This phase depends on local electron beam parameters such as the energy spread and the peak current. In this paper, we examine the effects of local density variations on the cooling rates for CeC. Coherent Electron Cooling (CeC) [1] is a new concept in intense, high energy hadron beamcooling, in which the Debye screened charge perturbation calculated in [2] is used to seed a high-gain free electron laser (FEL). Using delays to give the perturbing hadron an energy-dependent longitudinal displacement relative to its frequencymodulated charge perturbation, the hadron receives an energy-dependent kick which reduces its energy variation from the design energy. The equations of motion in [1] assume that the electron bunch is the same physical size as the hadron bunch, and has a homogeneous charge density across the entire bunch. In practice, the electron bunches will be much shorter than the hadron bunch, and this local spacial inhomogeneity in the charge distribution will alter the gain length of the FEL, resulting in both a change in the amplification of the initial signal and a phase shift. In this paper we consider these inhomogeneity effects, determining cooling equations for bunched beam CeC consistent with these effects and determining thresholds for the cooling parameters