1,075 research outputs found
Developing of modern cultivation technology of organic potatoes
Medium term field experiment demonstrates the effectiveness of biological ways to
increase potatoes yield on the sod-podzolic, light loamy soil.
The effects of the following two groups of factors were studied:
1. The level of mineral nutrition provided by compost;
2. Microbiological pant protection product (bio preparations): Flavobacterin which has
N fixer attribute and Vitaplan and Kartofen, which have bio fungicide features.
Potatoes varieties ‘Nevsky’ and ‘Udacha’ were cultivated. The compost was applied in the dose
range from 0 to 160 kg N ha-1
. Treatment with bio-preparations was carried out by potato tubers
during planting and leaves during the growing season. Weeds were removed mechanically.
Weather conditions had a significant impact on the formation of the crop. The average yield of
standard potato tubers for 2017–2018 ranged from 14.1 to 29.3 t ha-1
. The use of both
microbiological preparations and compost gave approximately the same effect and increased
yields by 35–37% compared to the control. The use of compost together with bio-preparations
provided an output of 27.6–29.3 t ha-1of potatoes. In 2019, the joint use of compost and biopreparations allowed to reach a yield of 40 tons ha-1 of marketable potatoes. On the basis of the
obtained data, the mathematical dependences of the yield of potatoes on the dose of compost, the
type of biological preparation and the complex indicator of the year conditions were determined
Condensate fraction and critical temperature of a trapped interacting Bose gas
By using a mean field approach, based on the Popov approximation, we
calculate the temperature dependence of the condensate fraction of an
interacting Bose gas confined in an anisotropic harmonic trap. For systems
interacting with repulsive forces we find a significant decrease of the
condensate fraction and of the critical temperature with respect to the
predictions of the non-interacting model. These effects go in the opposite
direction compared to the case of a homogeneous gas. An analytic result for the
shift of the critical temperature holding to first order in the scattering
length is also derived.Comment: 8 pages, REVTEX, 2 figures, also available at
http://anubis.science.unitn.it/~oss/bec/BEC.htm
Conserving and Gapless Approximations for an Inhomogeneous Bose Gas at Finite Temperatures
We derive and discuss the equations of motion for the condensate and its
fluctuations for a dilute, weakly interacting Bose gas in an external potential
within the self--consistent Hartree--Fock--Bogoliubov (HFB) approximation.
Account is taken of the depletion of the condensate and the anomalous Bose
correlations, which are important at finite temperatures. We give a critical
analysis of the self-consistent HFB approximation in terms of the
Hohenberg--Martin classification of approximations (conserving vs gapless) and
point out that the Popov approximation to the full HFB gives a gapless
single-particle spectrum at all temperatures. The Beliaev second-order
approximation is discussed as the spectrum generated by functional
differentiation of the HFB single--particle Green's function. We emphasize that
the problem of determining the excitation spectrum of a Bose-condensed gas
(homogeneous or inhomogeneous) is difficult because of the need to satisfy
several different constraints.Comment: plain tex, 19 page
Geology, geochemistry, mineralogy and genesis of the Spetsugli high-germanium coal deposit in the Pavlovsk coalfield, Russian Far East
The geology, mineralogy, and geochemistry of the Spetsugli high-germanium coal deposit in the Pavlovsk coalfield were studied. The deposit is characterized by the complex polyelemental composition of the ores and can be evaluated as a complex rare metal-coal deposit. The metal-bearing coals of the deposit are characterized by abnormally high, tens or even hundreds of times greater than the mean contents for brown coals of the world, for Ge, Sb, Hg, W, Li, Be, Cs, and As. Somewhat less anomalous are the levels of accumulation of U, Mo, Y, Rb, medium and heavy lanthanides, Zn, and Ga. Detailed mineralogical and geochemical characteristics of the germanium mineralization and associated anomalous concentrations of W, Sb, Hg, As Li, Be, Cs, U, Mo, Y, Rb, and HREE are described in the paper. The variations in concentrations were studied in vertical profiles and laterally. Complex mineralogical-geochemical and geological-structural analysis of the composition and structural features of the Spetsugli Ge-coal deposit allow us to revise the accepted hydrothermal model of the Ge mineralization formation in coals and substantiate the previously proposed hypergenic model for deposits of this type. The new data are in good agreement with the hydrogenic hypergenic model of the formation of complex Ge coal deposits where the source of metals is the basement rocks or the coal-bearing depression margins. The formation of the Ge and associated mineralization in the Spetsugli deposit was controlled by the weathering crust formation on hydrothermally altered rare metal granites of the Voznesenk Complex, broken through by the Late Permian dikes. The isotopic ages of the granites (448.2 Ma) and dikes (263.6 Ma) were determined and also the rhyolitic tuffs (25.1 Ma) which overlie the Eocene-Oligocene coal- bearing sediments in the basin. The isotopic age of the granites (448.2 Ma), dikes (263.6 Ma), and rhyolite tuffs overlapping the carbonaceous deposits (25.1 Ma) was determined. The rare metal mineralization is related to the basement protrusion in the centre of the deposit, forming a concentric-zone halo of Ge and associated elements around it. The basement protrusion granites were hydrothermally altered to form quartz-albite-microcline metasomatites and greisen containing the W-Mo and Hg-Sb-As mineralization. The metasomatically altered granites and dikes were transformed into a kaolin weathering crust as a result of late hypergenic alterations, with destruction of primary endogenous mineralization and removal of major elements to the surrounding paleopeatlands. Both types of endogenous mineralization in granites and dikes have anomalous accumulation of W, Mo, Sb, Hg, As, Li, Rb, Cs, Be, U, Y, lanthanides, Zn and Ga in the germanium-bearing coals during the Eocene- Oligocene time
Radiation hardness of polysiloxane-based scintillators
Polysiloxane-based scintillators with different contant of aromatic chromophore groups have been obtained. 2,5-diphenyloxazole and its alkyl derivative were used as activators. The optical and scintillation properties of the obtained polysiloxane scintillators have been studied, and their radiation resistance has been determined. The prospect of using the material in fields with high dose loads is estimated.Отримано сцинтилятори на полісилоксанових основах, що містять у своєму складі різну кількість ароматичних хромофорних груп. Як активатори використано 2,5-дифенілоксазол і його алкілпохідне. Вивчено оптичні та сцинтиляційні властивості отриманих полісилоксанових сцинтиляторів, визначена їх радіаційна стійкість. Оцінено перспективу використання матеріалу в полях з великими дозовими навантаженнями.Получены сцинтилляторы на полисилоксановых основах, содержащих в своем составе разное количество ароматических хромофорных групп. В качестве активаторов использованы 2,5-дифенилоксазол и его алкилпроизводное. Изучены оптические и сцинтилляционные свойства полученных полисилоксановых сцинтилляторов, определена их радиационная стойкость. Оценена перспектива использования материала в полях с большими дозовыми нагрузками
Radiation hardness of polysiloxane-based scintillators
Polysiloxane-based scintillators with different contant of aromatic chromophore groups have been obtained. 2,5-diphenyloxazole and its alkyl derivative were used as activators. The optical and scintillation properties of the obtained polysiloxane scintillators have been studied, and their radiation resistance has been determined. The prospect of using the material in fields with high dose loads is estimated.Отримано сцинтилятори на полісилоксанових основах, що містять у своєму складі різну кількість ароматичних хромофорних груп. Як активатори використано 2,5-дифенілоксазол і його алкілпохідне. Вивчено оптичні та сцинтиляційні властивості отриманих полісилоксанових сцинтиляторів, визначена їх радіаційна стійкість. Оцінено перспективу використання матеріалу в полях з великими дозовими навантаженнями.Получены сцинтилляторы на полисилоксановых основах, содержащих в своем составе разное количество ароматических хромофорных групп. В качестве активаторов использовано 2,5-дифенилоксазол и его алкилпроизводное. Изучены оптические и сцинтилляционные свойства полученных полисилоксановых сцинтилляторов, определена их радиационная стойкость. Оценена перспектива использования материала в полях с большими дозовыми нагрузками
Relaxation rates and collision integrals for Bose-Einstein condensates
Near equilibrium, the rate of relaxation to equilibrium and the transport
properties of excitations (bogolons) in a dilute Bose-Einstein condensate (BEC)
are determined by three collision integrals, ,
, and . All three collision integrals
conserve momentum and energy during bogolon collisions, but only conserves bogolon number. Previous works have considered the
contribution of only two collision integrals, and . In this work, we show that the third collision integral makes a significant contribution to the bogolon number
relaxation rate and needs to be retained when computing relaxation properties
of the BEC. We provide values of relaxation rates in a form that can be applied
to a variety of dilute Bose-Einstein condensates.Comment: 18 pages, 4 figures, accepted by Journal of Low Temperature Physics
7/201
MHV Vertices and Scattering Amplitudes in Gauge Theory
The generic googly amplitudes in gauge theory are computed by using the
Cachazo-Svrcek-Witten approach to perturbative calculation in gauge theory and
the results are in agreement with the previously well-known ones. Within this
approach we also discuss the parity transformation, charge conjugation and the
dual Ward identity. We also extend this calculation to include fermions and the
googly amplitudes with a single quark-anti-quark pair are obtained correctly
from fermionic MHV vertices. At the end we briefly discuss the possible
extension of this approach to gravity.Comment: Latex file, 38 pages, 15 figures; v2, minor changes, references
added; v2, minor changes, 2 references adde
MHV Vertices and Fermionic Scattering Amplitudes in Gauge Theory with Quarks and Gluinos
The Cachazo-Svrcek-Witten approach to perturbative gauge theory is extended
to gauge theories with quarks and gluinos. All googly amplitudes with
quark-antiquark pairs and gluinos are computed and shown to agree with the
previously known results. The computations of the non-MHV or non-googly
amplitudes are also briefly discussed, in particular the purely fermionic
amplitude with 3 quark-antiquark pairs.Comment: 41 pages, 21 figures; v2, minor changes, references added;v3, 2
important additions, references adde
Radiative decays of light vector mesons
The new data on radiative decays into
from SND experiment at VEPP-2M
collider are presented.Comment: 5 pages, 2 figures, talk given at 8th International Conference on
Hadron Spectroscopy (HADRON 99), Beijing, China, 24-28 Aug 199
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