In this work,shear strain modeling in materials consisting of a thin polymer layer(~15 nm),adhesive bonded to a rigid substrate,considered not to be impacted by deformation,was performed.A discrete-continuum model of ...In this work,shear strain modeling in materials consisting of a thin polymer layer(~15 nm),adhesive bonded to a rigid substrate,considered not to be impacted by deformation,was performed.A discrete-continuum model of chains system with a given stiffness with polar groups is developed.The polymer chain was considered in the framework of the persistene model,and the polar groups were based on the lattice model on the tetragonal lattice.It was assumed that the main contribution to the energy of interchain interactions is due to the potential of the polar groups and was calculated using the Metropolis algorithm.The potential interactions between the nearest polar groups of chains included the energy of dipole–dipole interactions(Keesom energy)and the Lennard–Jones potential.It is taken into account that the possible orientations of the polar groups are determined by the average elongation of the chain.Calculations showed that the dependence of free energy on the interchain distance has two minima.The first minimum is characterized by the orientational ordering of the polar groups,the second—by their disordered state.The depth and position of the minima depend on temperature,bending stiffness of the chain,the modulus of the dipole moment of the polar groups and the depth of the potential well in the Lennard–Jones energy.A step-by-step simulation of shear strain in a polymer layer in an orientationally disordered state was carried out.The obtained stress–strain diagrams make it possible to estimate the value of the elastic limit and also to determine the stresses at the points of phase transitions from a disordered to an orientationally ordered state.展开更多
Three novel β-cyclodextrin compounds derived with piperidine which is flexible, L-proline containing a chiral center, ionic liquid with 3,5-diamino-1,2,4-triazole as the cation were designed and synthesized as chiral...Three novel β-cyclodextrin compounds derived with piperidine which is flexible, L-proline containing a chiral center, ionic liquid with 3,5-diamino-1,2,4-triazole as the cation were designed and synthesized as chiral selectors for enantiomer separation, whose name were(mono-6-deoxy-6-(piperidine)-β-cyclodextrin, mo no-6-deoxy-6-( L-p ro li ne)-β-cyclodextri n, mono-6-deoxy-6-(3,5-diamino-1,2,4-triazole)-β-cyclodextrin, multi-substituted 3,5-diamino-1,2,4-triazole-(p-toluenesulfonic)-β-cyclodextrin),respectively. In addition, to enhance the polarity of chiral stationary phases, hydrosilylation and silylation reactions were implemented to derive ordinary silica, the common used selector carrier, to hydride silica, whose surface is covered with proton. 31 pyrrolidine compounds and some chiral drugs were tested in both polar organic mobile phase mode and normal mobile phase mode. 6-Deoxy-6-Lproline-β-cyclodextrin-CSP showed satisfactory separations in polar organic mobile phase mode and exihibited a strong separation capability in different pH values; multi-substituted 3,5-diamino-1,2,4-triazole-(p-toluenesulfonic)-β-cyclodextrin-CSP can separate pyrrolidine compounds in both mobile phase modes with high resolutions and separation efficiency compared to commercially available CSPs,making it to be the most valuable object to study. The composition of mobile phase, type of stationary phase as well as the peak problem of chromatograms was discussed deeply.展开更多
The Polar Urals region of northern Russia is well known for large chromium （Cr）-bearing massifs with major chromite orebodies, including the Centralnoye I deposit in the Ray-Iz ultramafic massif of the Ural ophiolit...The Polar Urals region of northern Russia is well known for large chromium （Cr）-bearing massifs with major chromite orebodies, including the Centralnoye I deposit in the Ray-Iz ultramafic massif of the Ural ophiolite belt. New data on platinum （Pt）-group elements （PGE）, geochemistry and mineralogy of the host dunite shows that the deposit has anomalous iridium （Ir） values. These values indicate the predominance of ruthenium--osmium--iridium （Ru--Os--Ir）-bearing phases among the platinum-group mineral （PGM） assemblage that is typical of mantle-hosted chromite ores. Low Pt values in chromites and increased Pt values in host dunites might reflect the presence of cumulus PGM grains. The most abundant PGM found in the chromite is erlichmanite （up to 15 μm）. Less common are cuproiridsite （up to 5 μm）, irarsite （up to 4--5 μm）, and laurite （up to 4 μm）. The predominant sulfide is heazlewoodite, in intergrowth with Ni--Fe alloys, sporadically with pentlandite, and rarely with pure nickel. Based on the average PGE values and esti- mated Cr-ore resources, the Centralnoye I deposit can be considered as an important resource of PGE.展开更多
基金The study was supported by the Russian Foundation for Basic Research,Project No.19-42-350001.
文摘In this work,shear strain modeling in materials consisting of a thin polymer layer(~15 nm),adhesive bonded to a rigid substrate,considered not to be impacted by deformation,was performed.A discrete-continuum model of chains system with a given stiffness with polar groups is developed.The polymer chain was considered in the framework of the persistene model,and the polar groups were based on the lattice model on the tetragonal lattice.It was assumed that the main contribution to the energy of interchain interactions is due to the potential of the polar groups and was calculated using the Metropolis algorithm.The potential interactions between the nearest polar groups of chains included the energy of dipole–dipole interactions(Keesom energy)and the Lennard–Jones potential.It is taken into account that the possible orientations of the polar groups are determined by the average elongation of the chain.Calculations showed that the dependence of free energy on the interchain distance has two minima.The first minimum is characterized by the orientational ordering of the polar groups,the second—by their disordered state.The depth and position of the minima depend on temperature,bending stiffness of the chain,the modulus of the dipole moment of the polar groups and the depth of the potential well in the Lennard–Jones energy.A step-by-step simulation of shear strain in a polymer layer in an orientationally disordered state was carried out.The obtained stress–strain diagrams make it possible to estimate the value of the elastic limit and also to determine the stresses at the points of phase transitions from a disordered to an orientationally ordered state.
文摘Three novel β-cyclodextrin compounds derived with piperidine which is flexible, L-proline containing a chiral center, ionic liquid with 3,5-diamino-1,2,4-triazole as the cation were designed and synthesized as chiral selectors for enantiomer separation, whose name were(mono-6-deoxy-6-(piperidine)-β-cyclodextrin, mo no-6-deoxy-6-( L-p ro li ne)-β-cyclodextri n, mono-6-deoxy-6-(3,5-diamino-1,2,4-triazole)-β-cyclodextrin, multi-substituted 3,5-diamino-1,2,4-triazole-(p-toluenesulfonic)-β-cyclodextrin),respectively. In addition, to enhance the polarity of chiral stationary phases, hydrosilylation and silylation reactions were implemented to derive ordinary silica, the common used selector carrier, to hydride silica, whose surface is covered with proton. 31 pyrrolidine compounds and some chiral drugs were tested in both polar organic mobile phase mode and normal mobile phase mode. 6-Deoxy-6-Lproline-β-cyclodextrin-CSP showed satisfactory separations in polar organic mobile phase mode and exihibited a strong separation capability in different pH values; multi-substituted 3,5-diamino-1,2,4-triazole-(p-toluenesulfonic)-β-cyclodextrin-CSP can separate pyrrolidine compounds in both mobile phase modes with high resolutions and separation efficiency compared to commercially available CSPs,making it to be the most valuable object to study. The composition of mobile phase, type of stationary phase as well as the peak problem of chromatograms was discussed deeply.
文摘The Polar Urals region of northern Russia is well known for large chromium （Cr）-bearing massifs with major chromite orebodies, including the Centralnoye I deposit in the Ray-Iz ultramafic massif of the Ural ophiolite belt. New data on platinum （Pt）-group elements （PGE）, geochemistry and mineralogy of the host dunite shows that the deposit has anomalous iridium （Ir） values. These values indicate the predominance of ruthenium--osmium--iridium （Ru--Os--Ir）-bearing phases among the platinum-group mineral （PGM） assemblage that is typical of mantle-hosted chromite ores. Low Pt values in chromites and increased Pt values in host dunites might reflect the presence of cumulus PGM grains. The most abundant PGM found in the chromite is erlichmanite （up to 15 μm）. Less common are cuproiridsite （up to 5 μm）, irarsite （up to 4--5 μm）, and laurite （up to 4 μm）. The predominant sulfide is heazlewoodite, in intergrowth with Ni--Fe alloys, sporadically with pentlandite, and rarely with pure nickel. Based on the average PGE values and esti- mated Cr-ore resources, the Centralnoye I deposit can be considered as an important resource of PGE.
