Exchange Energy Research Articles

Analysis of Exchange Power in the Power System of an Unmanned Aerial Vehicle with a BlDC Engine

The purpose of this work is the analysis of the power supply system of unmanned aerial vehicle. One of the most important tasks of this system is to ensure the smallest possible losses in order to achieve greater endurance of the aircraft, which means – the ability to complete the mission. The presence of an inactive component of consumed power obviously reduces the efficiency of the entire unmanned aerial vehicle. Considering also that due to the influence of wind, speed changes and other factors, the power system spends a significant amount of time in the transition mode, the impact of this phenomenon becomes even more significant. Thus, the phenomenon of the occurrence of exchange power in the power supply system of an unmanned aerial vehicle is analyzed. One of the most common solutions for unmanned aerial vehicles is the use of a BLDC motor, which is a further development of DC motors and was created with the aim of improving their basic characteristics. This type of engine has gained its popularity due to numerous advantages: high reliability, efficiency, speed and others. The principles of control of the BLDС engine are given. The unmanned aerial vehicle power supply system, built on the basis of a buck converter and a bridge inverter, was analyzed. An equivalent circuit of the converter is built, taking into account the losses in the electric circuit. On its basis the relations for determining the value of exchange power in the power supply system are derived. With the help of these expressions, it is possible to determine the value of the exchange energy at an arbitrary time interval in the real power supply system of the aircraft. A model of the power supply system of an unmanned aerial vehicle with a BLDC engine was built in the Matlab Simulink software environment. A time diagram is obtained, on the basis of which it is possible to draw a conclusion about the content of exchange power in the converter circuit. To minimize this phenomenon, it is necessary to develop a compensation system or an intelligent control system.

Multi objective ecological optimization of an irreversible Stirling cryogenic refrigerator cycle

The primary objective of the current study is to demonstrate the multi-objective, ecological optimization of an irreversible Stirling cycle-based cryogenic refrigerator. The novelty of the work lies in the ecological optimization of the system, where irreversibilities are considered during the study and the thermal reservoirs have finite energy. The heat source and heat sink exchange energy with the working fluid and respective thermodynamic processes are carried out. The aim is to maximize the ecological objective function and the ecological coefficient of performance, and the effect of design variables on the objective function is investigated. The heat sink capacitance rate, temperature ratio, heat source, and sink capacitance rates, and effectiveness of the hot and cold side heat exchangers are regarded as the design variables. A heat transfer search algorithm is used to optimize the objective functions, and multiple optimal solutions are presented using the Pareto optimal curve. The multi-criteria decision technique TOPSIS is employed to select the ideal solution. For an ideal point selected through TOPSIS, the system works at an optimum ECF and ECOP of 787 W and 5.9, respectively. The ECOP of the system for the current study is 1.81 times and 4.03 times higher than the existing literature. However, the maximum ECF of 1797 W or maximum ECOP of 17.2 can be obtained for the given constraints of design variables.

How the Exchange Energy Can Affect the Power Laws Used to Extrapolate the Coupled Cluster Correlation Energy to the Thermodynamic Limit.

Finite size error is commonly removed from coupled cluster theory calculations by N-1 extrapolations over correlation energy calculations of different system sizes (N), where the N-1 scaling comes from the total energy rather than the correlation energy. However, previous studies in the quantum Monte Carlo community suggest an exchange-energy-like power law of N-2/3 should also be present in the correlation energy when using the conventional Coulomb interaction. The rationale for this is that the total energy goes as N-1 and the exchange energy goes as N-2/3; thus, the correlation energy should be a combination of these two power laws. Further, in coupled cluster theory, these power laws are related to the low G scaling of the transition structure factor, S(G), which is a property of the coupled cluster wave function calculated from the amplitudes. We show here that data from coupled cluster doubles calculations on the uniform electron gas fit a function with a low G behavior of S(G) ∼ G. The prefactor for this linear term is derived from the exchange energy to be consistent with an N-2/3 power law at large N. Incorporating the exchange structure factor into the transition structure factor results in a combined structure factor of S(G) ∼ G2, consistent with an N-1 scaling of the exchange-correlation energy. We then look for the presence of an N-2/3 power law in the energy. To do so, we first develop a plane-wave cutoff scheme with less noise than the traditional basis set used for the uniform electron gas. Then, we collect data from a wide range of electron numbers and densities to systematically test five methods using N-1 scaling, N-2/3 scaling, or combinations of both scaling behaviors. We find that power laws that incorporate both N-1 and N-2/3 scaling perform better than either alone, especially when the prefactor for N-2/3 scaling can be found from exchange energy calculations.

High energy γ-rays inelastic scattering studies and DFT strategies of divalent high-Z perovskites EuTMO3 (TM = Ti and Zr)

Electron momentum densities (EMDs) of divalent high-Z perovskites EuTiO3 and EuZrO3 have been measured using 20 Ci 137Cs Compton spectrometer at 0.34 a.u. (momentum resolution). Theoretical directional and isotropic Compton profiles (CPs) for both the perovskites have been deduced using linear combination of atomic orbitals (LCAO) scheme with density functional theory (DFT). The DFT approximation dependent local density and generalized gradient approximations (GGA) along with second order GGA (SOGGA) and hybrid WC1LYP are considered in the present work. While validating the approximation for exchange and correlation energies using experimental CPs, the WC1LYP scheme has been identified as a better prescription for both the perovskites. To scrutinize the nature of bonding, we have calculated the Mulliken's populations (MP) and also scaled the experimental EMDs on equal-valence-electron-density, which explicitly show that EuTiO3 is more ionic than the EuZrO3. Going beyond the CPs, the electronic properties like energy bands and density of states (DOS) have also been enumerated using full potential linearized augmented plane wave (FP-LAPW) with GGA and GGA+Hubbard correction (U). Both the compounds show semiconducting behaviour with FP-LAPW-GGA+U scheme.

Competition between exchange and magnetostatic energies in domain pattern transfer from BaTiO3 (111) to a Ni thin film

We use spin-polarized low-energy electron microscopy to investigate domain pattern transfer in a multiferroic heterostructure consisting of a (111)-oriented ${\mathrm{BaTiO}}_{3}$ substrate and an epitaxial Ni film. After in situ thick-film deposition and annealing through the ferroelectric phase transition, interfacial strain transfer from ferroelastic domains in the substrate and inverse magnetostriction in the magnetic thick film introduce a uniaxial in-plane magnetic anisotropy that rotates by ${60}^{\ensuremath{\circ}}$ between alternating stripe regions. We show that two types of magnetic domain wall can be initialized in principle. Combining experimental results with micromagnetic simulations, we show that a competition between the exchange and magnetostatic energies in these domain walls has a strong influence on the magnetic domain configuration.

Gap Filling Method and Estimation of Net Ecosystem CO2 Exchange in Alpine Wetland of Qinghai–Tibet Plateau

The net ecosystem CO2 exchange (NEE) and water and energy fluxes at the alpine ecosystem level were obtained through the eddy covariance technique in an alpine wetland of the Longbao Region, Qinghai–Tibet Plateau. Our research used the NEE as the research object combined with meteorological factors. The NEE prediction model was constructed using Reddyproc and machine learning. Moreover, the effects of the data and features on the models and the selection of the model parameters were discussed. The results revealed the following information: (1) After removing the NEE outliers according to the friction wind speed thresholds of the different seasons, the NEE interpolation accuracy (R2) reached 0.65. Additionally, the NEE data dispersion decreased after removing the outliers, and the data quality improved effectively. (2) The decision coefficients (R2) of the eight kinds of combined machine learning algorithm models varied from 0.22 to 0.62, and the root mean square error (RMSE) ranged from 2.10 to 2.99 μmol s−1 m−2. Additionally, the multilayer perceptron (MLP) model had the best stability and the best interpolation effect. (3) There was a seasonal difference between the estimated values of Reddyproc and the estimated values of MLP. The monthly mean values of January, February, March, and October were lower than the monthly mean values of the latter, while the monthly mean values from April to September were higher than the monthly mean values of the latter, indicating that the prediction of the machine learning algorithm tends towards the carbon source in the cold season (nongrowing season) and tends towards the carbon sink in the warm season (growing season). (4) Reddyproc detected the outliers through the relationship between the night NEE and frictional wind speed, which made it possible to accurately estimate the nighttime flux under the condition of determining the threshold of the night frictional wind speed, thus obtaining a better NEE estimate with fewer input parameters. Before the training and prediction of the MLP model, the NEE was detected for the time series outliers, and the prediction accuracy was significantly improved, indicating that the elimination of the time series outliers is essential for NEE model training and further indicating that the understanding of the potential mechanism of the NEE is of great significance for the prediction model.

Coulomb, exchange, kinetic, nuclear attraction and ionization energies of two-electron quantum dot with finite confinement potential

We have calculated Coulomb, exchange and configuration-average ionization energies for the ground and excited configurations in helium atom confined by a spherical cavity of finite barrier height. In addition, we have carried out kinetic energies, nuclear attraction energies, confining potential energies and probabilities of finding the electrons that occupy different subshells. In the strong and intermediate confinement regions, the results show that the barrier height of potential well and dot size have a strong influence on the energies and probabilities. The kinetic energies of electrons in 1s and nl orbitals increase as the height of the potential barrier increases, but in nuclear attraction energies the opposite behavior occurs. It is found that Coulomb and exchange energies rapidly decrease after the critical confinement radii, in which the electron in nl orbital escapes out of the well. The configuration-ionization confinement radius depends strongly on the potential barrier height.

Crystallite size-dependent magnetic moment in hydrogen bridged manganese tetracyanonickelate based two-dimensional metal-organic frameworks

Two-dimensional (2D) metal–organic frameworks (MOFs) are the coordination network of organic cyanide (CN) ligands and metal cyanometallates. They possess great potential as molecular magnets between subzero up to above room temperature. These complexes are greatly sought after due to the unique structural features that allow them to offer tunable magnetic properties by changing crystal entities and/or through external stimulation such as light and heat. Layered structure of tetracyanonickellate based MOFs T(H2O)2Ni(CN)4·.4H2O, T = Mn herein called Mn-MOF, have been synthesized by the chemical precipitation method with controlled particle size using tri-sodium citrate dihydrate (TSCD) as the chelating agent. This work involves the study of spontaneous magnetism in the layered solid, the effect of their crystallite sizes and morphology on the magnetic susceptibility. The magnetic interaction takes place in-plane between the pseudo-octahedral metal (T) ions through the diamagnetic Ni2+ center, and out-of-plane through the hydrogen bonding bridge formed in the interlayer spacing. Magnetic properties were measured using Vibrating Sample Magnetometry (VSM) and calculated for Curie temperatures with magnetic exchange energies using the Curie-Weiss mean field theory and total angular momentum of the involved metal ions. The MOFs exhibit a paramagnetic behavior above 50 K and show increased magnetic susceptibility on cooling with a paramagnetic to weak ferromagnetic (wFM) transition below 50 K. A field-dependent response of the magnetic ordering temperature from 34 to 44 K was also observed for the Mn(H2O)2Ni(CN)4·.4H2O complex. The value of magnetic exchange coupling between interlayer metal centers increases though the hydrogen bonding network which results increased magnetic moment with decreased crystallite surface area to volume ratio.

Efficiency of winter barley cultivation methods for herbage for bulk feed conservation

The article presents the results of the economic and bioenergetic assessment of winter barley cultivation methods for harvesting bulky fodder. In a short-term experiment the effect of five levels of mineral nutrition on two methods of tillage in the crop rotation link soybean – winter barley, on fused leached chernozems of the southern foothill zone of Adygea has been studied. Differentdepth methods of tillage have been used for 20–22 cm (plowing) and 12–16 cm (surface tillage). As a background on the variants, the main fertilizer ammophos and ammonium nitrate have been used as top dressings (N30; N45; N60). It has been revealed that the use of surface treatment reduces the yield of winter barley green mass by 21-41%. The average yield varied from 8.8 for surface tillage to 12.8 t/ha for plowing. The highest level of productivity is 19.2 for plowing and 12.0 t/ha for surface treatment. It has been revealed that the green mass of the studied varieties of winter barley in 1 kg of natural feed contains, on average, from 0.42 to 0.605 EFU (energy feed units). Analysis of the nutritional value of the obtained green mass has shown: in 1 kg of dry matter of feed for plowing: crude protein 10.1%, exchange energy 11.72 MJ, feed units (Ke) 1.12; for surface treatment – 8.8%, 11.72 MJ, 1.13 (Ke). The highest yield has been formed according to the cultivation method, with the introduction of 60 kg of a.i. N by background (N24 P104) – by plowing. The most profitable plowing option is: Background + N60 (Romans variety), with a yield of 19.2 t / ha, the profit from the sale is 10603.8 thousand rubles, the profitability level is 58.3%. Bioenergetic assessment of cultivation methods has shown that for each unit of energy invested in the production of winter barley green mass, on the best options, from 2.75 to 2.92 units of energy have been obtained.

Productivity of cereal grasses with different ripening time depending on fertilizers

Aim. To determine productivity indicators of perennial cereal grasses with different ripening time depending on fertilizer. Methods. Field, laboratory, mathematical-statistical, economic-mathematical. Results. The results of studies on the productivity of perennial cereal grasses with different ripening time depending on fertilization on the sod-podzolic soil of the Carpathian region conducted during 2011−2013 are shown. Conclusions. Productivity of various types of perennial grasses on nitrogen-free backgrounds varied between 2.53–3.71 t/ha of dry weight, 1.81–2.67 t/ha of feed units, 0.27–0.42 t/ha of crude protein and 20.4−30.4 GJ/ha of exchangeable energy. The most productive were perennial fenugreek, festuca orientalis, awnless brome and reed canary grass. Nitrogen is the most effective nutrient element for the productivity of cereal grass stands. With the introduction of P60K60, compared to the option without fertilizers, productivity increases by 3–23%, N90 against the background of phosphorus and potassium – by 1.8–2.1 times. The difference in harvest ripeness between early- and medium-ripening grass stands in the 1st mowing was 12 days, and between early- and late-ripening – 22 days.

Direct numerical simulation of particle-laden flow in an open channel at

We perform two-way coupled direct numerical simulation of particle-laden flow in an open channel at a friction Reynolds number ( $Re_{\tau }$ ) of 5186, which exhibits many characteristics of high-Reynolds-number wall-bounded turbulence, such as the distinct separation of scales in the inner and outer layers. Three representative cases, an unladen case and low- and high-Stokes-number particle-laden cases, are performed to investigate the turbulent modification by particles. To this end, we compare several statistical quantities to understand the particle effect on momentum exchange and interphasial energy transfer. The modulation of large-scale motions (LSMs) and very-large-scale motions (VLSMs) are analysed using spectral information, and we find that the LSMs and VLSMs are generally weakened in the inner and outer layers, which is qualitatively different from similar simulations at lower Reynolds numbers ( $Re_{\tau } \approx 500$ ). The spatial structures are investigated with correlation analysis, and inclined VLSMs are observed in the near-wall region, with decreased inclination angles by particles. The particles tend to widen and shorten the spanwise and streamwise extent of coherent structures, respectively. Furthermore, we find that the vorticity vector displays a preferential alignment with the eigenvector corresponding to the intermediate eigenvalue of the strain-rate tensor, independent of the particle Stokes number.

Recent Developments on Understanding Charge Transfer in Molecular Electron Donor-Acceptor Systems.

Charge transfer (CT) in molecular electron donor-acceptor systems is pivotal for artificial photosynthesis, photocatalysis, photovoltaics and fundamental photochemistry. We summarized the recent development in study of CT and discussed its application in thermally activated delayed fluorescence (TADF) emitters. The direct experimental proof of the spin multiplicity of the charge separated (CS) state with pulsed laser excited time-resolved electron paramagnetic resonance (TREPR) spectroscopy was discussed. Experimental determination of the electron exchange energy (J) of the CS state, with magnetic field effect on its yield or lifetime was introduced. The electron spin transfer accompanying the CT, studied with pulsed EPR spectra was briefly discussed. Tuning of the CT yield and kinetics with selective vibration excitation of the linker (the bridge) with IR pulse was presented. Above all, these studies show that there are more fun than simply monitoring the formation of the cations and anions and the kinetics or CS yields in this area.

Recent Developments on Understanding Charge Transfer in Molecular Electron Donor‐Acceptor Systems

AbstractCharge transfer (CT) in molecular electron donor‐acceptor systems is pivotal for artificial photosynthesis, photocatalysis, photovoltaics and fundamental photochemistry. We summarized the recent development in study of CT and discussed its application in thermally activated delayed fluorescence (TADF) emitters. The direct experimental proof of the spin multiplicity of the charge separated (CS) state with pulsed laser excited time‐resolved electron paramagnetic resonance (TREPR) spectroscopy was discussed. Experimental determination of the electron exchange energy (J) of the CS state, with magnetic field effect on its yield or lifetime was introduced. The electron spin transfer accompanying the CT, studied with pulsed EPR spectra was briefly discussed. Tuning of the CT yield and kinetics with selective vibration excitation of the linker (the bridge) with IR pulse was presented. Above all, these studies show that there are more fun than simply monitoring the formation of the cations and anions and the kinetics or CS yields in this area.

Kinetic Analysis of the Cation Exchange in Nanorods from Cu2-xS to CuInS2: Influence of Djurleite's Phase Transition Temperature on the Mechanism.

In the syntheses of ternary I-III-VI2 compounds, such as CuInS2, it is often difficult to balance three precursor reactivities to achieve the desired size, shape, and atomic composition of nanocrystals. Cation exchange reactions offer an attractive two-step alternative, by producing a binary compound with the desired morphology and incorporating another atomic species postsynthetically. However, the kinetics of such cation exchange reactions, especially for anisotropic nanocrystals, are still not fully understood. Here, we present the cation exchange reaction from Cu-deficient djurleite Cu2-xS nanorods to wurtzite CuInS2, with size and shape retention. With reaction parameters in a broad temperature range between 40 °C and 160 °C, we were able to obtain various intermediates. Djurleite has a bulk phase transition temperature at 93 °C, which influences the cation exchange considerably. Below the phase transition temperature, indium is only incorporated into the surface of the nanorods, while, at temperatures above the phase transition temperature, we observe a Janus-type exchange mechanism and the formation of CuInS2 bands in the djurleite nanorods. The findings suggest that the diffusion above the phase transition temperature is strongly favored along the copper planes of the copper sulfide nanorods over the diffusion through the sulfur planes. This results in a difference of 37 kJ mol-1 in the activation energy of the cation exchange below and above the phase transition temperature.

Effects of Coix seed extract, Lactobacillus paracasei K56, and their combination on the glycolipid metabolism in obese mice.

Coix seed extract (CSE) and probiotics have been reported to regulate glycolipid metabolism through different modes of action. We tested the effects of CSE, Lactobacillus paracasei K56, and their combination to determine whether they have synergistic effects on glycolipid metabolism of obese mice. We fed male C57BL/6J mice with high-fat diet for 8 weeks to establish an obesity model. The obesity mice were selected and divided into five groups: the model control group and four intervention groups. After 10 weeks of continuous gavage intervention, the mice in the intervention groups exhibited lower body weight (lower about 2.31-4.41g, vs. HFD 42.25g, p<0.01), and epididymal (lower about 0.58-0.92g, vs. HFD 2.50g, p<0.01) and perirenal fat content (lower about 0.24-0.42g, vs. HFD 0.88g, p<0.05); decreased fasting blood glucose, total cholesterol, triglycerides, and VLDL; and increased HLDL, respiratory exchange ratio, energy expenditure, and amount of exercise performed. K56+CSE-combined intervention groups were more effective in lowering blood glucose, IL-1β, and TNF-α levels than the CSE and K56 alone interventions. The content of fatty acid synthase and SREBP-1c protein in liver tissue was lower. The combination has synergistic effects on weight control, fat reduction, and blood glucose regulation by improving the chronic inflammatory state and reducing the content of lipid synthesis-related enzymes of obese mice, which can hinder chronic disease progression. PRACTICAL APPLICATION: Coix seed extract can be used in obese people to regulate abnormal glucose and lipid metabolism and delay the development of chronic diseases.

Magnetization Dynamics in FexCo1-x in Presence of Chemical Disorder

In this paper, we present a theoretical formulation of magnetization dynamics in disordered binary alloys, based on the Kubo linear response theory, interfaced with a seamless combination of three approaches: density functional-based tight-binding linear muffin-tin orbitals, generalized recursion and augmented space formalism. We applied this method to study the magnetization dynamics in chemically disordered FexCo1−x (x = 0.2, 0.5, 0.8) alloys. We found that the magnon energies decreased with an increase in Co concentration. Significant magnon softening was observed in Fe20Co80 at the Brillouin zone boundary. Magnon–electron scattering increased with increasing Co content, which in turn modified the hybridization between the Fe and Co atoms. This reduced the exchange energy between the atoms and softened down the magnon energy. The lowest magnon lifetime was found in Fe50Co50, where disorder was at a maximum. This clearly indicated that the damping of magnon energies in FexCo1−x was governed by hybridization between Fe and Co, whereas the magnon lifetime was controlled by disorder configuration. Our atomistic spin dynamics simulations show reasonable agreement with our theoretical approach in magnon dispersion for different alloy compositions.

ТЕХНИКА И ТЕХНОЛОГИЯ ПОВЕРХНОСТНОГО УЛУЧШЕНИЯ ПОЙМЕННЫХ ЛУГОВ РЕСПУБЛИКИ ТАТАРСТАН

Research with the aim of developing and implementing highly effective methods of surface improvement of floodplain meadows with partial preservation of old herbage and sowing of new perennial grasses based on the widespread use of modern integrated agricultural machines and implements was carried out in 2016-2020 in the Republic of Tatarstan. The scheme of the experiment included the following options: processing of the sod of the floodplain meadow (factor A) – without processing; disking BDN 4 ×4 + flat-cutting processing to a depth of 22 ...24 cm KPG-2-150; processing with a universal cultivator-planar cutter with piercing action harrows (KPU-5,4) of the Perm Machine-Building Plant; processing with a cultivator-planar cutter equipped with a perforating action harrow (KPBL-3) of the Kazan State Agrarian University design; sowing of perennial grasses and mineral fertilizers (factor B) – without sowing and without fertilizers; sowing of alfalfa-stalk grass mixture at the rate of 12 kg/ha (6 million pcs/ha of germinating seeds) in combination with annual application in spring N45P20K45. The control was a natural grass stand without processing, without sowing and without applying mineral fertilizers. The results of the research have shown high efficiency of the complex application of the following agrotechnical techniques: layer-by-layer tillage using a cultivator-planer equipped with a perforating action harrow (KPBL-3), sowing seeds of perennial grasses and annual spring fertilizing N45P20K45. At the same time, the yield of the green mass of the floodplain meadow increases by 2.74 times compared to the original herbage, the profitability of feed production is 73.6%, the cost price is reduced to 6910 rubles. at the selling price for 1000 feed units, 12,000 rubles. The total energy costs for surface improvement of the floodplain meadow increase from 18.4 in the control variant to 21.6 GJ/ha, however, the accumulation of exchange energy in feed outstrips these costs by 3.2 times.

Angular momentum conservation in spin-lattice dynamics simulations

Kuzkin's angular momentum balance method is implemented in the LAMMPS SPIN package for atomistic spin-lattice dynamics, along with shifted-force exchange and N\'eel Hamiltonians parameterized to minimize energy drifts in the simulations. Angular momentum contributions arising from two mechanisms are quantified using this method: particle transport across the boundaries of a periodic simulation domain and external torques applied to the domain by periodic image atoms. When these mechanisms are accounted for, lattice angular momentum is exactly conserved in lattice systems and in spin-lattice systems with isotropic exchange interactions. The calculations show that spin-lattice angular momentum exchange only occurs when the N\'eel anisotropy energy is added to the exchange energy, and that with this addition, total angular momentum is approximately conserved in the magnetization direction but not in other directions. Inclusion of the N\'eel anisotropy increases the energy drifts observed in simulations of iron nanoparticles. These drifts are linearly proportional to the magnitude of the anisotropy energy and the simulation time step.

Modulating Exchange Bias, Anisotropic Magnetoresistance, and Planar Hall Resistance of Flexible Co/MnN Epitaxial Bilayers on Mica by Bending Strain.

The integration of ferromagnetic/antiferromagnetic bilayers with exchange bias effect on flexible substrates is crucial for flexible spintronics. Here, the epitaxial Co/MnN bilayers are deposited on mica by facing-target sputtering. A large in-plane exchange bias field (HEB) of 1800 Oe with a coercive field (HC) of 2750 Oe appears in the Co (3.8 nm)/MnN (15.0 nm) bilayer at 5 K after field cooling from 300 to 5 K. Effective interfacial exchange energy Jeff of the Co/MnN bilayer is 0.83 erg/cm2. The strain-induced maximum increase of HEB and HC reaches 18% and 21%, respectively, in the Co(3.8 nm)/MnN(15.0 nm) bilayer. Strain-modulated HEB is attributed to the change of interfacial exchange coupling between Co and MnN layers. HEB is inversely proportional to Co thickness but independent of MnN thickness. The change of HEB is less than 5% after 100 bending cycles, indicating mechanical durability. The out-of-plane exchange bias also appears since Co spins are not fully reversed due to the strong pinning effect. Anisotropic magnetoresistance (AMR) and planar Hall resistance (Rxy) show obvious hysteresis due to HEB. Exchange bias-induced phase difference of AMR and Rxy almost remains unchanged at different bending strains. The results provide the basis for understanding the bending strain tailored exchange bias.

Green mass productivity and quality of new sweet sorghum varieties in the ARC “Donskoy”

Introduction. In order to realize productive potential of any crop, a variety is of great importance. There is a number of requirements imposed on modern varieties, including not only productivity and quality, but alsocompliance with environmental and climatic conditions, resistance to unfavorable conditions, adaptability to mechanized harvesting. The purpose of the current work was to identify effective methods for developing sweet sorghum varieties, to estimate the sweet sorghum varieties developed by the Agricultural Research Center “Donskoy”” according to productivity and quality of green mass for silage. Methods. The paper presents the study results on the development and research of new sweet sorghum varieties in the Agricultural Research Center “Donskoy”” (Rostov region) through the years 2019–2021. The soil was an ordinary carbonate chernozem, with 3.6 % of humus in the arable layer. The objects of the study were sweet sorghum varieties. The ways to conduct trials, soil tillage and cultivation, as well as zootechnical analysis of green mass were determined according to generally accepted methods. Results. When developing a new variety, a number of characteristicsneeds to be taken into account according to which breeding is carried out from year to year, namely suitability for mechanized harvesting, stem succulence, tillering, stem diameter, length of a vegetation period, sugar content in stem sap, productivity and its main elements, etc. There are such methods for developing sweet sorghum varieties in the Agricultural Research Center “Donskoy”” as hybridization, incubation and selection of constant forms. As a result of the breeding work, there has been developed a number of varieties. In the State List there are 5 varieties of the Agricultural Research Center “Donskoy””. Green mass productivity of the new varieties Yuzhnoe and Feniks was 36 and 42 t/ha, respectively. The sugar-protein ratio of the variety Feniks was normal (1.1 : 1). Silage is recommended to be combined with protein cultures. The yield of exchangeable energy in green mass for silage (for cattle) obtained from new sweet sorghum varieties was 13.5–14.1 MJ/ha.