Influence of weather condtion on the field peas (PisumsativumL.ssp. sativum) vegetation period and yield

Field pea (Pisumsativum L. ssp. sativum) is a universal pulse crop. One of the actual problems in its production is the influence of weather condition on the variability of pea economic characters and its properties. The purpose of the research (2009–2018) was to compare the vegetation period and interstage periods of the Hangildin and Chishminskiy 229 pea varieties with weather condition and seed yield. According to the results of the conducted research, it can be seen that the duration of the vegetation period and the yield of field pea grain was influenced by weather condition. The average daily air temperature affected the duration of the sowingsprouting period in pea varieties Hangildin and Chishminskiy 229. The duration of the two periods (sprouting-flowering and flowering-ripeness) was influenced by features of the used varieties and the temperature condition (r = -0.472, the link is significant and r = -0.788). The duration of the sprouting-ripeness period depended on the average daily temperatures (r = -0.481), the amount of precipitation (r = 0.937), and the HTC (hydrothermal coefficient) (r = 0.927). Precipitation increased the duration of the full vegetation period (r = 0.892). On average, over 10 years of research on field pea it should be noted that there wasa close relationship between the duration of its vegetation period (r = 0.844), the duration of the flowering-ripeness period (r = 0.679) and the yield of seeds. The relationship between the seed yield and the sowing - sprouting period (r = 0.451) and between the seed yield and the sprouting - flowering period (r = 0.446) was revealed. The connection was found positive. The connection with the average daily air temperature of this period was negative (r = -0.213). The results of the research can be successfully used during cultivation of domestic and foreign varieties of field pea. In international practice, the results of this experiment can be successfully applied in selective improvement of field pea and the development of new, high-tech varieties

Morphological and structural features of the CdxPb1−xS films obtained by CBD from ethylenediamine-citrate bath

The calculating of ionic equilibria in the system «Pb(CH3COO)2 - CdCl2 - Na3C6H5O7 - ‎(NH3)2(CH2)2 - N2H4CS» allowed us to find conditions and concentration regions of PbS and CdS co-deposition. The determined conditions provided the CBD obtaining of CdxPb1−xS (0 ≤ x ≤ 0.033) substitutional solid solutions films with a cubic structure B1 (space group Fm ) with the grains preferred orientation (200). We established the evolution of the surface morphology of the synthesized films from cubic crystallites to hierarchical structure of globular aggregates by scanning electron microscopy. A quantitative analysis of diffraction patterns showed a decrease of microstrains in CdxPb1−xS films by a about factor of 3 with an increase of the cadmium chloride concentration in the reaction mixture from 0.005 to 0.14 mol/l. The excess of the cadmium content, established by EDX analysis, in the studied films as compared to its content in the solid solution is associated with the additional formation of the amorphous CdS phase up to 72 mol %.A Corrigendum is available for this article at https://doi.org/10.15826/chimtech.2021.8.2.12

Research of medical students’ motivation for studying mathematical disciplines

Mathematical disciplines within the educational programs of medical training are currently represented by a small number of auditory working hours. Most students do not focus on studying these disciplines, because they lack motivation. It is significant to examine motivational attitudes of medical students in relation to mathematical disciplines carefully in order to improve the teaching process.The problem of the research is to define resources of medical students’ motivation while studying mathematical disciplines.The research objectives are to reveal the incentives encouraging future doctors to study mathematical disciplines thoroughly.The research methods used are the method of survey, the method of analyzing products of activity, the method of generalization and systematization of the data obtained.The research results are the following: the incentives motivating medical students to study mathematical disciplines have been highlighted, the interconnection between motivational attitudes and students’ personal interests have been identified; the reasons influencing future doctors’ motivation to study mathematical disciplines have been defined; the principles of organizing mathematical training for medical students in the context of the motivational component of the university educational process have been named.Key findings are: the quality of medical students’ performance depends on the nature of their motivational attitudes towards the type of the discipline given; enhancing practice-oriented component while selecting educational material has a positive impact on the dynamics of future physicians’ motivation to study mathematical disciplines

Proton and Oxygen-Ion Conductivities of Hexagonal Perovskite Ba5In2Al2ZrO13

The hexagonal perovskite Ba5 In2Al2ZrO13 and In3+-doped phase Ba5 In2.1Al2Zr0.9O12.95 were prepared by the solid-state synthesis method. The introduction of indium in the Zr-sublattice was accompanied by an increase in the unit cell parameters: a = 5.967 Å, c = 24.006 Å vs. a = 5.970 Å, c = 24.011 Å for doped phase (space group of P63 /mmc). Both phases were capable of incorporating water from the gas phase. The ability of water incorporation was due to the presence of oxygen deficient blocks in the structure, and due to the introduction of oxygen vacancies during doping. According to thermogravimetric (TG) measurements the compositions of the hydrated samples corresponded to Ba5 In2Al2ZrO12.7 (OH)0.6 and Ba5 In2.1Al2Zr0.9O12.54 (OH)0.82. The presence of different types of OH−-groups in the structure, which participate in different hydrogen bonds, was confirmed by infrared (IR) investigations. The measurements of bulk conductivity by the impedance spectroscopy method showed that In3+-doping led to an increase in conductivity by 0.5 order of magnitude in wet air (pH2O = 1.92·10−2 atm); in this case, the activation energies decreased from 0.27 to 0.19 eV. The conductivity−pO2 measurements showed that both the phases were dominant proton conductors at T < 500◦C in wet conditions. The composition Ba5 In2.1Al2Zr0.9O12.95 exhibited a proton conductivity ~10−4 S·cm−1 at 500◦C. The analysis of partial (O2−, H+, h•) conductivities of the investigated phases has been carried out. Both phases in dry air (pH2O = 3.5·10−5 atm) showed a mixed (oxygen-ion and hole) type of conductivity. The obtained results indicated that the investigated phases of Ba5 In2Al2ZrO13 and Ba5 In2.1Al2Zr0.9O12.95 might be promising proton-conducting oxides in the future applications in electrochemical devices, such as solid oxide fuel cells. Further modification of the composition and search for the optimal dopant concentrations can improve the H+-conductivity. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 22-23-20003Funding: This research was supported by the Russian Science Foundation and Government of Sverdlovsk region, Joint Grant 22-23-20003 https://rscf.ru/en/project/22-23-20003/

The Gd2−x Mgx Zr2 O7−x/2 Solid Solution: Ionic Conductivity and Chemical Stability in the Melt of LiCl-Li2 O

Materials with pyrochlore structure A2 B2 O7 have attracted considerable attention owing to their various applications as catalysts, sensors, electrolytes, electrodes, and magnets due to the unique crystal structure and thermal stability. At the same time, the possibility of using such materials for electrochemical applications in salt melts has not been studied. This paper presents the new results of obtaining high-density Mg2+-doped ceramics based on Gd2 Zr2 O7 with pyrochlore structure and comprehensive investigation of the electrical properties and chemical stability in a lithium chloride melt with additives of various concentrations of lithium oxide, performed for the first time. The solid solution of Gd2−x Mgx Zr2 O7−x/2 (0 ≤ x ≤ 0.10) with the pyrochlore structure was obtained by mechanically milling stoichiometric mixtures of the corresponding oxides, followed by annealing at 1500◦ C. The lattice parameter changed non-linearly as a result of different mechanisms of Mg2+ incorporation into the Gd2 Zr2 O7 structure. At low dopant concentrations (x ≤ 0.03) some interstitial positions can be substituted by Mg2+, with further increasing Mg2+-content, the decrease in the lattice parameter occurred due to the substitution of host-ion sites with smaller dopant-ion. High-density ceramics 99% was prepared at T = 1500◦ C. According to the results of the measurements of electrical conductivity as a function of oxygen partial pressure, all investigated samples were characterized by the dominant ionic type of conductivity over a wide range of pO2 (1 × 10–18 ≤ pO2 ≤ 0.21 atm) and T < 800◦ C. The sample with the composition of x = 0.03 had the highest oxygen-ion conductivity (10−3 S·cm−1 at 600◦ C). The investigation of chemical stability of ceramics in the melt of LiCl with 2.5 mas.% Li2 O showed that the sample did not react with the melt during the exposed time of one week at the temperature of 650◦ C. This result makes it possible to use these materials as oxygen activity sensors in halide melts. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Russian Foundation for Basic Research, РФФИ: 20-43-660033Funding: The work is financially supported by RFBR and Sverdlovsk region, project number 20-43-660033

New and Old Results in Resultant Theory

Resultants are getting increasingly important in modern theoretical physics: they appear whenever one deals with non-linear (polynomial) equations, with non-quadratic forms or with non-Gaussian integrals. Being a subject of more than three-hundred-year research, resultants are of course rather well studied: a lot of explicit formulas, beautiful properties and intriguing relationships are known in this field. We present a brief overview of these results, including both recent and already classical. Emphasis is made on explicit formulas for resultants, which could be practically useful in a future physics research.Comment: 50 pages, 15 figure