The temperature–frequency dependence of the complex elastic modulus of an adhesive composition based on unsaturated polyketone was studied by dynamic mechanical analysis. It was shown that, in the ...temperature range of –100 to +60°C, two relaxation processes occur, which are related to the presence of two polymer networks in an adhesive composition. The regularities of the effect of γ radiation on the temperature dependence of the complex elastic modulus of an adhesive composition were established.
Interrelation between the morphology, physiology, biochemistry, and productivity of potato plants was shown for the first time using the example of a mid-season-ripening variety (v.) Siversky and a ...mid-early Tretyakovka v. The yield of Siversky v. turned out to be 1.6 times higher than the yield of Tretyakovka. Aboveground biomass of Siversky v. was distinguished by an increased content of photosynthetic pigments, a greater variability of the protein and lipid metabolism indicators, and more intense oxidation processes and antioxidant protection, which can be the key to its greater productivity. Multivariate statistical analysis showed that the greatest relationship in the climatic conditions of central Russia in 2020 was found for productivity and such indicators as the stomata number per unit leaf area, the number of stems, and the content of pigments, phospholipids, neutral lipids, and water-soluble part of the protein. Thus, both morphological and physiological–biochemical properties can influence the course and direction of the production process, and, hence, the yield of a certain variety.
The purpose of the study is to identify the relationship between drought resistance indicators and the yield of potato plants under unfavorable conditions. A xeromorphic leaf structure is considered ...to be a diagnostic sign of plant drought resistance. The objects of the study were 24 potato varieties. Planting of seeds, preplanting tillage, harvesting, and crop recording were carried out in the period of 2020–2022 on the territory of the Samara Research Institute of Agriculture (branch of the Samara Scientific Center, Russian Academy of Sciences). Growing conditions for 2021 and 2022 were characterized by elevated temperatures and insufficient moisture. The number and size of stomata per unit leaf area were chosen as the criterion for xeromorphism. The studied varieties were divided into two groups (
n
= 12 each) according to the number of stomata. In the first group, the average number of stomata was 26 000 pcs./cm
2
of leaf, and that in the second group was 35 000 pcs. (
F
= 41,
p
= 0.03). More developed structural features of xeromorphism and the accumulation of certain types of metabolites in the second group of varieties led to a 1.6 times greater yield than in the first less xeromorphic group (
F
= 9,
p
= 0.004). The second group was characterized by a large number of mesophyll cells per unit leaf area (584 000 pcs./cm
2
vs. 557 000 pcs.), high content of phospholipids (36 mg/g dry weight vs. 31 mg/g), dry weight (0.19 vs. 0.17 g/g wet weight), and the ratio of membrane lipids to membrane proteins (1.4 vs. 1.2). In the less xeromorphic group of plants, the level of oxidative stress, assessed by LPO products, was 0.050 μM/g fresh weight and was 12% higher than in the more xeromorphic group (
F
= 6,
p
= 0.08). The revealed positive correlation between yield and xeromorphic genotypes indicates the prospects of using this criterion in potato breeding or creating a variety model.
The contribution of the morpho-physiological parameters of leaves and tubers of 22 potato varieties (
Solanum tuberosum
L.) to the formation of yield under conditions of insufficient soil moisture ...and high air temperatures is studied. Discriminant analysis found that the stomata size (12%), chlorophyll content (10%), number of tubers (29%), and average tuber weight (21%) determined the gradation of plants by yield. The specific surface density of leaves (38%), the content of chlorophyll (13%) and carotenoids (13%), and the leaf area (12%) made the greatest contribution to discrimination in relation to ecological plasticity. It is concluded that the number of stomata per unit area of the leaf, the specific surface density of the leaf, and the content of photosynthetic pigments are the key characteristics that contribute to both the high yield and the adaptive capacity of potatoes.
Twenty-four potato (
Solanum tuberosum
L.) varieties differing in ripening groups (early, middle-early, and mid-season-ripening) were studied. Potatoes were grown under the conditions of the Middle ...Volga region of Russia in 2019–2021. It was found statistically that the yield (t/ha) of the early and mid-season-ripening varieties was negatively correlated with the increase in average temperatures during the growing season from May to August (
R
= –0.97,
p
= 0.04). Soil moisture content at a depth of 20 cm was positively correlated with the yield of middle-early varieties (
R
= 0.97,
p
= 0.04). The average tuber weight in the early varieties was sensitive to the increase in average temperatures (
R
= –0.95,
p
= 0.04). An increase in soil moisture content was beneficial to the average tuber weight (
R
= 0.98,
p
= 0.04), though only in the middle-early and mid-season-ripening groups. However, the soil moisture content and the tuber numbers in the mid-season-ripening varieties were negatively correlated (
R
= –0.96,
p
= 0.05).
Studies of the chemical structure of ionic liquids and its influence on the curing regularities and the properties of epoxide-containing liner compositions and the epoxy binder were performed. The ...used ionic liquids were compounds in which imidazolium and pyrrolidinium cations correspond to dicyanamide and tetracyano-borate anions. It was shown that ionic liquids with a dicyanamide anion possess a catalytic activity that is expressed in acceleration of curing of the epoxy-rubber liner composition, the EDT-10 epoxy binder, and the microorganoplastic on its basis. It was established that the use of ionic liquids as a curing catalyst instead of dimethylbenzylamine does not affect physical and mechanical characteristics, such as lifetime, strength, swelling in transformer oil, and structural glass-transition temperature of the liner composition and provides a high stable strength of microorganoplastic.
A method is proposed for the formation of ZnO nanoparticles (NP) in dimethylformamide, which permits variation of the mean NP diameter from 3.6-3.7 to 6.0 nm by selecting the suitable duration and ...temperature of the post-synthesis heat treatment. The ZnO nanoparticles in DMF display characteristic photoluminescence, emitting in a broad band with maximum at 2.24-2.25 eV, with a quantum yield up to 13%, and a mean radiative lifetime of ~2 μs. Giant enhancement of Raman scattering on the surface phonons of the ZnO NP is observed upon the photoexcitation of these NP with an island-like silver film deposited on their surface.
Changes in the characteristics of a high-filled polymeric compound are investigated in the area of its fastening to a rigid multilayer substrate. It is established that, in the fastening area, an ...increase in the amount of the rubber sol-fraction and the content of the high-filled polymeric compound plasticizer is observed, as well as an increase in the modulus of elasticity and a decrease in the strain of the HFPC.
A study of the influence of ionic liquids on the curing and properties of a strengthening composition based on polyesterurethane rubber with epoxyurethane end groups has been carried out. The ...catalytic activity of ionic liquids has been found to be dependent on the anion chemical structure and to increase as the anion size decreases. It has been shown that introduction of methylbenzylamine and ionic liquid (1-ethyl-3-methyl-imidazolyl dicyanamide) results in strengthening compositions with close mechanical properties, lifetime, swelling in transformer oil, and glass transition temperature.
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