144 research outputs found

    Structure of natural impact glasses on AFM data

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    This work was supported by the RSF (project No. 17-17-01080)

    Mild template synthesis of copper(II)-containing macrocyclic compounds in the CuII-1,2-diaminoethanedithione-1,2-ethanedione-1,2 and Cu II-1,2-diamino-ethanedithione-1,2-butanedione-2,3 triple systems into Cu2[Fe(CN)6]-gelatin-immobilized matrix implantates

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    The complexing processes in the CuII-1,2-diaminoethanedithione- 1,2-ethanedione-1,2 and CuII-1,2-diaminoethanedithione-1,2- butanedione-2,3 triple systems occuring in the copper(II)hexacyanoferrate(II) gelatin-immobilized matrix in contact with aqueous alkaline solutions (pH~12) containing 1,2-diaminoethanedithione-1,2 and ethanedione-1,2 or butanedione-1,2 under room temperature, and between MCl2, 1,2-diaminoethanedithione- 1,2 and ethanedione-1,2 or butanedione-1,2 in the ethanol solutions, upon heating up to ~80 °C, have been studied. In both systems indicated, template synthesis occurs in the gelatin-immobililized matrix but does not occur in the ethanol solution. As a result of template synthesis, macrocyclic CuII chelates with 2,7-dithio-3,6-diazaoctadien-3,5-dithioamide-1,8 and its 4,5-dimethylsubstituted derivative are formed in the gelatin-immobililized matrix. 1,2-diaminoethanedithione-1,2 and ethanedione-1,2 or butanedione-2,3 are the ligand synthons in the processes indicated. © 2007 Springer

    Copper(II)- heterocyclic compounds with 4,5-dimethyl-2,3,6,7-tetraazaoctadien-3,5-dithiohydrazide-1,8 and 3,10-dithio-6,7,13,14-tetramethyl-1,2,4,5,8,9,11, 12-octaazacyclotetradekatetraen-1,5,7,12 obtained in gelatin- immobilized matrix as a result of template synthesis

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    Soft template synthesis of macrocyclic coordination compounds with 4,5-dimethyl-2,3,6,7-tetraaza-octadien-3,5-dithiohydrazide-1,8 and 3,10-dithio-6,7,13,14-tetramethyl-1,2,4,5,8,9,11, 12-octaazacyclo-tetradekatetraen-1,5,7,12 in the triple Cu(II)-thiocarbohydrazide- 2,3- butanedione system in the copper(II)hexacyanoferrate(II) gelatin-immobilized matrix has been carried out. Also, it has been established that similar process in the nickel(II)hexacyanoferrate(II) matrices does not occur under such conditions

    Mild template synthesis in the Cu(II)-dithiomalonamide-formaldehyde ternary system

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    Complex formation in the ternary system Cu(II)-dithiomalonamide H 2NC(=S)CH2C(=S)NH2-formaldehyde in aqueous ethanol containing copper(II) chloride, dithiomalonamide and formaldehyde, as well as in thin-layer gelatin-immobilized copper(II) hexacyanoferrate(II) matrix implants contacting with alkaline (pH > 10) aqueous solutions containing the same organic compounds was studied. In the first case, a Cu(II) bischelate complex with singly deprotonated dithiomalonamide is formed exclusively, whereas in the second case template synthesis occurs to form a macrocyclic CuL chelate (L is 1,11-diamino-1,11-disulfanyl-4,8-diaza-6-oxaundeca-1,10-diene-3,9- dithione). In the latter case, dithiomalonamide and formaldehyde function as ligsons. The above-mentioned chelate is not formed on direct contact of the reagents in aqueus ethanol both in the presence and in the absence of Cu(II). A scheme of chemical reactions that occur in the system under consideration was proposed. © 2008 MAIK Nauka

    Interactions between diurnal winds and floodplain mosaics control the insect boundary layer in a river corridor

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    Insect flight along river corridors is a fundamental process that facilitates sustainable succession and diversity of aquatic and terrestrial insect communities in highly dynamic fluvial environments. This study examines variations in the thickness of the insect boundary layer (i.e., the pre-surface atmosphere layer in which air velocity does not exceed the sustained speed of flying insects) caused by interactions between diurnal winds and the heterogenous habitat mosaics in the floodplain of a braided river. Based on advective–diffusive theory, we develop and test a semi-empirical model that relates vertical flux of flying insects to vertical profiles of diurnal winds. Our model suggests that, in the logarithmic layer of wind, the density of insect fluxes decreases exponentially with the altitude due to the strong physical forcing. Inside the insect boundary layer, the insect fluxes can increase with the altitude while the winds speed remains nearly constant. We suggest a hypothesis that there is a close correspondence between the height of discontinuity points in the insect profiles (e.g. points with abrupt changes of the insect flux) and the displacement heights of the wind profiles (e.g. points above which the wind profile is logarithmic). Vertical profiles were sampled during three time-intervals at three different habitat locations in the river corridor: a bare gravel bar, a gravel bar with shrubs, and an island with trees and shrubs. Insects and wind speed were sampled and measured simultaneously over each location at 1.5-m intervals up to approximately 17 m elevation. The results support our working hypothesis on close correspondence between discontinuity and displacement points. The thickness of the insect boundary layer matches the height of the discontinuity points and was about 5 m above the bare gravel bar and the gravel bar with shrubs. Above the island, the structure of the insect boundary layer was more complex and consisted of two discontinuity points, one at the mean height of the trees’ crowns (ca. 15 m), and a second, internal boundary layer at the top of the shrubs (ca. 5 m). Our findings improve the understanding of how vegetation can influence longitudinal and lateral dispersal patterns of flying insects in river corridors and floodplain systems. It also highlights the importance of preserving terrestrial habitat diversity in river floodplains as an important driver of both biotic and abiotic (i.e., morphology and airscape) heterogeneity

    Interactions between diurnal winds and floodplain mosaics control the insect boundary layer in a river corridor

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    Insect flight along river corridors is a fundamental process that facilitates sustainable succession and diversity of aquatic and terrestrial insect communities in highly dynamic fluvial environments. This study examines variations in the thickness of the insect boundary layer (i.e., the pre-surface atmosphere layer in which air velocity does not exceed the sustained speed of flying insects) caused by interactions between diurnal winds and the heterogenous habitat mosaics in the floodplain of a braided river. Based on advective–diffusive theory, we develop and test a semi-empirical model that relates vertical flux of flying insects to vertical profiles of diurnal winds. Our model suggests that, in the logarithmic layer of wind, the density of insect fluxes decreases exponentially with the altitude due to the strong physical forcing. Inside the insect boundary layer, the insect fluxes can increase with the altitude while the winds speed remains nearly constant. We suggest a hypothesis that there is a close correspondence between the height of discontinuity points in the insect profiles (e.g. points with abrupt changes of the insect flux) and the displacement heights of the wind profiles (e.g. points above which the wind profile is logarithmic). Vertical profiles were sampled during three time-intervals at three different habitat locations in the river corridor: a bare gravel bar, a gravel bar with shrubs, and an island with trees and shrubs. Insects and wind speed were sampled and measured simultaneously over each location at 1.5-m intervals up to approximately 17 m elevation. The results support our working hypothesis on close correspondence between discontinuity and displacement points. The thickness of the insect boundary layer matches the height of the discontinuity points and was about 5 m above the bare gravel bar and the gravel bar with shrubs. Above the island, the structure of the insect boundary layer was more complex and consisted of two discontinuity points, one at the mean height of the trees’ crowns (ca. 15 m), and a second, internal boundary layer at the top of the shrubs (ca. 5 m). Our findings improve the understanding of how vegetation can influence longitudinal and lateral dispersal patterns of flying insects in river corridors and floodplain systems. It also highlights the importance of preserving terrestrial habitat diversity in river floodplains as an important driver of both biotic and abiotic (i.e., morphology and airscape) heterogeneit

    Template synthesis in the Cu(II)-dihydrazinomethanethione-acetone ternary system

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    Complex formation in the Cu(II)-dihydrazinomethanethione (H 2NHN-CS-NHNH2)-acetone ternary system in an ethanol solution containing CuCl2, dihydrazinomethanethione, and acetone, as well as on contact of gelatin-immobilized copper(II) hecacyanoferrate(II) with alkaline (pH >10) aqueous solutions containing the above organic compounds was studied. It was found that template synthesis is realized in both cases but gives different products: in the first case, a heteroligand chelate of CuL 1(OH) with 9-hydrazino-9-mercapto-4,6,6-trimethyl-2,3,7,8- tetraazanona-3,8-dienethiohydrazide and hydroxide ion is formed, while in the second, a chelate of CuL2 with 2,8,10,10,16-pentamethyl-3,4,6,7,11, 12,14,15-octaazaheptadeca-2,5,7,12,15-pentaene-5,13-dithiol. In both cases, dihydrazinomethanethione and acetone function as ligsons. A scheme of involved processes is suggested. © 2009 Pleiades Publishing, Ltd. Reerernces:

    Mild template synthesis of a copper(II)-containing macrocyclic compound with 4,4,6-trimethyl-2,3,7,8-tetraazanonen-6-dithiohydrazide-1,9 in a gelatin-immbolized matrix

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    The complexing processes in the triple copper(II)-thiocarbohydrazide-propanone system taking place in a copper(II) hexacyanoferrate(II) gelatin-immobilized matrix in contact with aqueous-alkaline solutions (pH∼12), containing thiocarbohydrazide and propanone, have been studied. Template synthesis leading to a macrocyclic coordination compound with the tetradentate N,N,S,S-donor ligand, (4,4,6-trimethyl-2,3,7,8-tetraazanonen-6-dithiohydrazide-1,9), occurs under these specific conditions when thiocarbohydrazide and propanone are the ligand synthons

    Soft template synthesis of macrocyclic copper(II) chelates with 3,9-dithio-4,8-diaza-6-oxaundekandithioamide-1,11 in a Cu 2[Fe(CN)6]-gelatin-immobilized matrix

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    Soft template synthesis of macricyclic copper(II) chelates with 3,9-dithio-4,8-diaza-6-oxaundekandithioamide-1,11 in a Cu 2[Fe(CN)6]-gelatin-immobilized matrix (GIM), was presented. The process of template synthesis between copper(II), dithiomalonamide and methanol occurred only in GIM. Results indicated that the complexing process in the system under examination was independent of the gelatin type

    Template synthesis in the M(II)-thiocarbohydrazide-diacetyl triple system (M = Ni, Cu) in a metal(II)hexacyanoferrate(II) gelatin-immobilized matrix

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    Novel complexing processes in the CuII-thiocarbohydrazide- diacetyl triple system proceeding to a copper(II)hexacyanoferrate gelatin-immobilized matrix system in contact with aqueous-alkaline (pH 12) solutions containing thiocarbohydrazide and diacetyl, have been studied. It has been shown that mild template synthesis of copper(II) coordination compounds with (N,S,N,S)- and (N,N,N,N)- tetradentate ligands - 4,5-dimethyl-2,3,6,7- tetraazaoctadien-3,5-dithiohydrazide-1,8 and 3,10-dithio - 6,7,13,14- tetramethyl-1,2,4,5,8,9,11,12-octaazacyclotetradecatetraene-1,5,7,12 take place, respectively. At the same time, the complexing process in the system under examination, when it occurs in aqueous-ethanol solution between CuCl2 and the organic compounds indicated, leads to copper(II) coordination compounds with another (N,S,N,S)-tetradentate ligand - 3,9,10,16-tetramethyl-6,13 - dimercapto-2,17-dioxo-4,5,7,8,11,12,14,15-tetraazaoctadecahexaene - 3,6,8,10,12,15. In both cases, thiocarbohydrazide and diacetyl are ligand synthons in these complexing processes
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