Влияние регуляторов роста на рост, продуктивность и качество урожая томата в условиях дельты Волги

Relevance. Tomato considered a significant vegetable crop that plays a prominent role in the field of human health. At present, there are large numbers of tomato cultivars with a wide range of morphological and sensorial characteristics which determine their use. Farmers often use some chemical substances which have similar structure and activity with endogenous plant hormone called (exogenous) as a low-cost alternative to regulate plant growth and increase yield. Thus, the use of Plant Growth Regulators (PGRs) has become an important component of the agro-technical procedures for most cultivated species.Methods. This study aims to evaluate the effect of four growth regulators (Krezacin, Chitosan, Zircon and Energene) on growth, productivity and quality of two Russian tomato varieties (Moriana and Superjol) under delta Volga conditions. Each type applied three times on both cultivars (Soaking tomato seeds before sowing, spraying on plants at vegetative phase, spraying on plants at flowering phase with three replications.Results. The results showed that; combination between Energene and cultivar Moriana enhanced the most of studied characters (Germination – 83.1%, fresh weight of Arial parts – 241.9 g, dry weight – 74.4 g, Number of № flowers/plant – 51.0, № fruits /plant – 35.6, fruit set – 69.8%, plant yield – 2.44 kg, TSS – 5.1°Brix, Content of Ascorbic Acid – 25.6 mg/100 g); Interaction between “Energene x Superjol” gave the maximum value for Plant height (85.6 cm), Fruit weight (72.6 g); while “Krezacin x Moriana” registered the highest fruit dry matter (6.77%) and Acidity (0.53%); Applying Zircon on Cultivar Moriana increased number of leaves/plant (56.8) and nitrate contents (27.6 mg/kg); the maximum LAI (150.1 cm2 ) obtained from interaction between Chitosan and cultivar Superjol whereas, “Chitosan x Moriana” treatment gave the highest level of Carotenoids (4.12%). Актуальность. Томат считается важной овощной культурой, которая играет большую роль в сохранении здоровье человека, поэтому исследования морфологических, физиологических и пищевых свойств томата актуальны. Фермеры часто используют некоторые химические вещества, которые имеют сходную структуру и активность с эндогенным растительным гормоном, называемым (экзогенным), в качестве недорогой альтернативы для регулирования роста растений и увеличения урожайности. Влияние многих из этих веществ на рост и качество сельскохозяйственных культур еще не изучено.Методика. Целью данного исследования является оценка влияния четырех регуляторов роста (Крезацин, Хитозан, Циркон и Энерген) на рост, продуктивность и качество двух российских сортов томата (Моряна и Супергол) в условиях дельты Волги.Результаты. Результаты показали, что использование Энерген на сорте Моряна усилило большинство изученных признаков (всхожесть – 83,1%, свежая масса вегетативных частей – 241,9 г, сухая масса вегетативных частей – 74,4 г, количество цветков / растений – 51,0, количество плодов / растений – 35,6, урожайность растений – 2,44 кг, сумма сахаров – 5,1°Brix, содержание аскорбиновой кислоты – 25,6 мг/100 г. Применение Энергена на сорте Супергол дало максимальное значение высоты растений (85,6 см), массы плода (72,6 г); в то время как при использовании Крезацина на сорте Mоряна было достигнуто самое высокое содержание сухого вещества в плодах (6,77%) и кислотность (0,53%). Применение Циркона на сорте Моряна привело к увеличению количества листьев на растении (56,8) и содержания нитратов (27,6 мг/кг). Максимальный LAI (150,1 см2 ) получен при использовании хитозана на сорте Супергол, тогда как его применение на сорте Моряна дало самый высокий уровень каротиноидов (4,12%).

Anomalous Resonance of the Symmetric Single-Impurity Anderson Model in the Presence of Pairing Fluctuations

We consider the symmetric single-impurity Anderson model in the presence of pairing fluctuations. In the isotropic limit, the degrees of freedom of the local impurity are separated into hybridizing and non-hybridizing modes. The self-energy for the hybridizing modes can be obtained exactly, leading to two subbands centered at $\pm U/2$. For the non-hybridizing modes, the second order perturbation yields a singular resonance of the marginal Fermi liquid form. By multiplicative renomalization, the self-energy is derived exactly, showing the resonance is pinned at the Fermi level, while its strength is weakened by renormalization.Comment: 4 pages, revtex, no figures. To be published in Physical Review Letter

Tight-binding modelling of the electronic band structure of layered superconducting perovskites

A detailed tight-binding analysis of the electron band structure of the CuO_2 plane of layered cuprates is performed within a sigma-band Hamiltonian including four orbitals - Cu3d_x^2-y^2, Cu4s, O2p_x, and O2p_y. Both the experimental and theoretical hints in favor of Fermi level located in a Cu or O band, respectively, are considered. For these two alternatives analytical expressions are obtained for the LCAO electron wave functions suitable for the treatment of electron superexchange. Simple formulae for the Fermi surface and electron dispersions are derived by applying the Loewdin down-fold procedure to set up the effective copper and oxygen Hamiltonians. They are used to fit the experimental ARUPS Fermi surface of Pb_0.42Bi_1.73Sr_1.94Ca_1.3Cu_1.92O_8+x and both the ARPES and LDA Fermi surface of Nd_2-xCe_xCuO_4-delta. The value of presenting the hopping amplitudes as surface integrals of ab initio atomic wave functions is demonstrated as well. The same approach is applied to the RuO_2 plane of the ruthenate Sr_2RuO_4. The LCAO Hamiltonians including the three in-plane pi-orbitals Ru4d_xy, O_a 2p_y, O_b 2p_x and the four transversal pi-orbitals Ru4d_zx, Ru4d_yz, O_a 2p_z, O_b 2p_z, are separately considered. It is shown that the equation for the constant energy curves and the Fermi contours has the same canonical form as the one for the layered cuprates.Comment: 21 pages, 10 figures, published in J. Phys.: Condens. Matter (complete and corrected References section

Universal scaling relation in high-temperature superconductors

Scaling laws express a systematic and universal simplicity among complex systems in nature. For example, such laws are of enormous significance in biology. Scaling relations are also important in the physical sciences. The seminal 1986 discovery of high transition-temperature (high-T_c) superconductivity in cuprate materials has sparked an intensive investigation of these and related complex oxides, yet the mechanism for superconductivity is still not agreed upon. In addition, no universal scaling law involving such fundamental properties as T_c and the superfluid density \rho_s, a quantity indicative of the number of charge carriers in the superconducting state, has been discovered. Here we demonstrate that the scaling relation \rho_s \propto \sigma_{dc} T_c, where the conductivity \sigma_{dc} characterizes the unidirectional, constant flow of electric charge carriers just above T_c, universally holds for a wide variety of materials and doping levels. This surprising unifying observation is likely to have important consequences for theories of high-T_c superconductivity.Comment: 11 pages, 2 figures, 2 table

СРАВНИТЕЛЬНЫЕ ИССЛЕДОВАНИЯ ФИЗИОЛОГО-ХИМИЧЕСКИХ СВОЙСТВ НЕКОТОРЫХ СОРТОВ ТОМАТА В УСЛОВИЯХ АРИДНОЙ ЗОНЫ

Currently, in southern regions of Russia, mainly, tomatoes of foreign breeding are grown. First of all, this is due to the fact that until recently Russian varieties could not compete with foreign in terms of storage, transportation and guaranteed yield. But in connection with sharp changes in weather conditions, in the direction of increasing critical temperatures, the relevance of cultivating modern varieties of tomato of Russian selection possessing high heatresistant characteristics becomes relevant. The varieties of Tomato Selection of All-Russian Scientific Research Institute of Irrigation Vegetable and Melon Growing served as an object of research. The biochemical properties of fruits depend very strongly on the conditions of growth of the crop and on the genetic potential of the variety. The most important biochemical indicators of tomato fruit are the amount of dry matter, the amount of sugars, the pH of fruit juice, carotene, vitamin C (ascorbic acid) and the amount of nitrates. These indicators determine the quality of tomato fruits (products). Five varieties of tomatoes were evaluated for quality changes. The content of solids is maximally in the Morayan variety 6.60±0.04%, the lowest in the Cascader variety is 4.06±0.07%, therefore the most optimal technical properties for the Morayan variety. The content of sugars is maximally in the Moryan variety 4.36±0.05%, the lowest in the stunt Kaskader 2.22±0.04%. The maximum pH of the fruit juice in the variety Cascader is 3.75±0.07 less acidic juice medium, the most acidic medium in the Malinovka variety is 2.75±0.03. The maximum content of carotene in the Moryan variety is 3.03±0.07 mg%, the minimum in the Kaskader variety is 1.26±0.05 mg%. The largest amount of nitrates is able to accumulate a variety of Petrovsky 68.3±0.04 mg%, the minimum quantity in the Supergol variety is 19.0±0.04mg%. The content of ascorbic acid is the highest in the Moryan variety 21.0±0.03 mg%, the lowest in the Petrovsky variety 9.77±0.02.В настоящее время в южных регионах России в основном выращивают сорта и гибриды томата иностранной селекции. Прежде всего, это связано с тем, что до последнего времени сорта российской селекции не могли конкурировать с иностранными по срокам хранения, транспортировке и гарантированно стабильной урожайности. Но в связи с резкими изменениями погодных условий в сторону повышения критических температур актуальность возделывания современных сортов томата российской селекции, обладающих высокими жаростойкими характеристиками, становится актуальным. В связи с чем в качестве объекта исследования служили сорта томата селекции ВНИИООБ. Опыты закладывали в 2015-2017 годах на капельном орошении на Опытном поле ВНИИООБ в Камызякском районе Астраханской области. Изучали сорта томата: Моряна (st), Каскадер, Петровский, Супергол и Чижик. В ходе исследования оценивали качество и физиологические параметры плодов: сухое вещество, сумма сахаров, рН сока, содержания каротина, аскорбиновой кислоты, нитратов. В результате исследований установлено, что содержание сухого вещества максимально у сорта Моряна 6.60±0,04%, минимально у сорта Каскадер 4.06±0,07%, поэтому самые оптимальные технические свойства у сорта Моряна. Содержание сахаров максимально у сорта Моряна – 4.36±0,05%, минимально – у сорта Каскадер – 2.22±0,04%. Максимальная рН сока плодов у сорта Каскадер – 3.75±0,07, менее кислая среда сока, самая кислая среда у сорта Малиновка – 2.75±0,03. Максимальное содержание каротина у сорта Моряна – 3.03±0,07 мг%, минимальное – у сорта Каскадер 1.26±0,05 мг%. Самое большое количество нитратов способен накапливать сорт Петровский 68.3±0,04 мг%, минимальное количество – сорт Супергол 19.0±0,04 мг%. Содержание аскорбиновой кислоты самое высокое у сорта Моряна 21±0,03 мг%, самое низкое у сорта Петровский 9.77±0,02.

Orbital Magnetoresistance in the LaSrCuO System

Measurements of resistivity, Hall effect, and magnetoresistance have been made on seven c-axis oriented thin-film specimens of La(2-x)Sr(x)CuO(4) with values of x from 0.048 to 0.275, and one specimen that also contains Nd. The orbital magnetoresistance is found not to be proportional to the square of the tangent of the Hall angle except for values of x near 0.15 above about 80K. For smaller values of x the temperature dependence of the magnetoresistance is different, but quite similar in the various specimens, in spite of large differences in resistivity, Hall coefficient, and Hall angle.Comment: LaTeX, 14 pages, 4 embedded color eps figure

Phase Fluctuations and Pseudogap Phenomena

This article reviews the current status of precursor superconducting phase fluctuations as a possible mechanism for pseudogap formation in high-temperature superconductors. In particular we compare this approach which relies on the two-dimensional nature of the superconductivity to the often used $T$-matrix approach. Starting from simple pairing Hamiltonians we present a broad pedagogical introduction to the BCS-Bose crossover problem. The finite temperature extension of these models naturally leads to a discussion of the Berezinskii-Kosterlitz-Thouless superconducting transition and the related phase diagram including the effects of quantum phase fluctuations and impurities. We stress the differences between simple Bose-BCS crossover theories and the current approach where one can have a large pseudogap region even at high carrier density where the Fermi surface is well-defined. The Green's function and its associated spectral function, which explicitly show non-Fermi liquid behaviour, is constructed in the presence of vortices. Finally different mechanisms including quasi-particle-vortex and vortex-vortex interactions for the filling of the gap above $T_c$ are considered.Comment: 129 pages, Elsart, 28 EPS figures; Physics Reports, in press. Authors related information under "http://nonlin.bitp.kiev.ua/~sharapov/superconductivity.html