02.00.00 Chemical sciences
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Description
The article presents the results of studies of changes in the atomic radii of isotopes of the elements of the periodic table. With using the mass-radial model of calculations, the values of atomic radii for isotopes of chemical elements were obtained. It is shown that the atomic radius of different isotopes of one element is different and depends on the mass and radius of the nucleus. To study the changes in ∆Rav values in the groups and periods of the Periodic Table of Chemical Elements, the ∆Rav dependences on the period number and group number are constructed. It is found that the values depending on the number ∆Rav period / group for the d-elements lie in the low ∆Rav values for selements - in high ∆Rav values, and p-elements - in average values ∆Rav. It is shown that when the atomic nucleus is increased by 1 neutron, the atomic radius increases from 0.01 to 4.76 pm, which is due to the physical effect inside the atom
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QuЕChERS SAMPLE PREPARATION IN THE DETERMINATION OF PESTICIDES OF DIFFERENT CHEMICAL CLASSES BY HPLC
DescriptionThe method has been developed of simultaneous determination of active ingredients of different kinds of pesticides in biological tissues (fish liver) by applying HPLC with ultra-violet detection and the rapid method of QuEChERS sample preparation. We defined optimum volume and composition of the reagents for the extraction, time of centrifugation and ultrasound treatment, the origin and composition of sorbents that ensure maximum extraction of the substances studied and further cleanup of interfering substances. Acetonitrile was used as a solvent. The extraction was carried out in the presence of a buffering mixture - trisodium citrate dihydrate and disodium citrate hemihydrate. Bondesil PSA bulk sorbents (alkylated amine containing two amine functional groups - secondary and primary) and C18E (reversed-phase sorbent based on silica gel with grafted octadecylsilane groups were used to purify the extract from coextractable substances (fats, proteins, sugars, organic and fatty acids, pigments and other impurities). The degree of extraction of the analyzed active ingredients of pesticides from the liver of fish was 79%. The detectable pesticide concentrations ranged from 0,4 to 0,97 mg/kg. The relative standard deviation of the analysis results amounted to 0,01-0,14
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DEVELOPMENT OF A METHOD FOR FIXING PERFTORSULFOPOLIMER MF-4SK ON A HETEROGENEOUS MEMBRANE-SUBSTRATE
DescriptionThe article illustrates the results of the research dedicated to finding a method of combining two polymeric materials - ion-exchange membranes having different chemical nature. It shows a method of applying a homogenous film MF 4SK on the surface of the heterogeneous membrane substrate to produce a chemically and mechanically stable asymmetric bipolar membrane. We have selected membrane substrate ensuring the best electrochemical performance
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DEVELOPMENT OF A NEW MODEL OF CALCULATIONS OF VALUES OF ATOMIC RADIUMS
DescriptionThe article presents the results of studies of changes in the atomic radii of the elements of the periodic table, depending on their atomic masses. It is shown that the appearance of p- and d-orbitals introduces a significant contribution to the value of the atomic radius, and the appearance of f-orbitals makes a significantly smaller contribution to the given value. A radial-mass model of calculations of atomic radii for the elements of the Periodic Table was developed. Optimal conditions for making calculations were chosen. For the first time the values of atomic radii for elements with the order number 103-120 are calculated. It is shown that the values of atomic radii for elements with the order number 103-120 are in the range from 140 to 335 picometers and regularly change in the period
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DEVELOPMENT OF TECHNOLOGY OF WHEY BASED DRINKS, ENRICHED WITH PLANT COMPONENTS
DescriptionData of application of researches of vegetative components in reception of drinks from dairy whey of a functional purpose are shown
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PLANT GROWTH REGULATORS IN THE SERIES OF NICOTINIC ACID DERIVATIVES
DescriptionThe article shows the information of the use of 2-R-sulfanyl nicotinates of potassium on rice crops. We have found that the compounds described increase yield and improve its quality
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SYNTESIS OF 2-R-4-HYDROXYMETHYL-6-METHYLNICOTINATES OF ALKALINE METALS
DescriptionNew 2-R-4-hydroxymethyl-6-methylnikotinates of alkaline metals are synthesized by alkaline hydrolysis of derivatives 6-methyl-1,3-dihydrofuro-[3,4-c]pyridine-3-on
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SYNTHESIS OF SUBSTITUTED ISOXAZOLO[5,4-b]PYRIDINE AND THEIR ANTIDOTE ACTIVITY
DescriptionTo develop the novel herbicide antidotes for the sunflower vegetative plants, the group of chemical compounds, belonging to the derivatives of isoxalopyrazolopyridines was synthesized and their antidote activity both in the laboratory and field experiments was studied. The compounds with a high antidote effect were found
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SYNTHESIS OF SUBSTITUTED PYRIDINE- 3-SULFONYL ISOCYANATES AND PYRIDINE- 3-SULFONYL UREAS
DescriptionAcylation of amides substituted with pyridine-3- sulfonic acids oxalil-chlorides and phosgene was studied. New pyridil-3-sulfonil isocyanates were synthesized. The conditions for this synthesis were optimized by taking into account the detailed understanding of this acylation. The synthesized pyridine-3-sulfonyl isozyanates were converted to pyridine-3-sulfonyl ureas. Biological activity of the new compounds was studied and the substances with high herbicidal effect were found
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Description
In this article the review about the results of syntheses of new derivatives of pyrasoles,I soxazoles and pyridines, containing furan fragment is given. New methods of the syntheses of material are offered and estimation of their biological activity is made