In this study, the structural, electronic and optical properties of DO3A-based boronic acid derivates with and without UO22+ ion are studied by density functional calculations with M062X/6 - 31 g + (d) method, in aque...In this study, the structural, electronic and optical properties of DO3A-based boronic acid derivates with and without UO22+ ion are studied by density functional calculations with M062X/6 - 31 g + (d) method, in aqueous media. The quantum chemical properties such as EHOMO, ELUMO, the energy gap (ΔE), chemical potential (μ), hardness (η) are also performed. The theoretical essential UV-Vis. bands of DO3A-UO2(VI)-APB-o are at 392 and 687 nm. DO3A-UO2 (VI)-ABB-o structure has two main bands at 393 and 650 nm. In general, the bathochromic shift occurs and the HOMO-LUMO energy gap decreases to about 2 eV, by binding UO22+ ion in three different media. The notable shifts in NMR spectrums have been found on α-carbon of carbonyl group, ring carbons and amide protons. In IR-spectrums, the prominent peaks belong to BO-H and N-H of amide stretching vibrations of calculated structures.展开更多
Copper-manganese-aluminum （CMA） alloys, containing small additions of Fe, Ni, and Si, exhibit good strength and remarkable corrosion resistance against sea water. The alloys are used in as-cast condition, and their ...Copper-manganese-aluminum （CMA） alloys, containing small additions of Fe, Ni, and Si, exhibit good strength and remarkable corrosion resistance against sea water. The alloys are used in as-cast condition, and their microstructure can show wide variations. The morphology, crystallography and composition of the phases presented in an as-cast （CMA） alloy of nominal composition Cu-14%Mn-8%Al-3%Fe-2%Ni were investigated using optical, electron optical, and microprobe analytical techniques. The as-cast microstructure consisted of the grains of fcc α and bcc β-phases alongwith intermetallic precipitates of various morphologies. The room temperature microstructure exhibited four different types of precipitates inside the α-grains： the ＇large＇ dendritic-shaped particles and the cuboid-shaped precipitates, which were rich in Fe and Mn and had an fcc structure, while the ＇small＇ dendritic-shaped particles and the globular precipitates were based on FeaAI and had DO3 structure. These four different morphologies of intermetallic precipitates exhibited discrete orientation-relationships with the α-matrix. The β-grains only contained very small cuboid shaped precipitates, which could only be resolved through transmission electron microscopy. These precipitates were found to be based on Fe3Al and had the DO3 structure.展开更多
A simple modified analytic EAM model for bcc Fe and fcc Al was used to calculate the lattice constant and elastic constants of B2 FeAl and DO3 Fe3Al alloys. The formation energies of vacancy and antisite were also cal...A simple modified analytic EAM model for bcc Fe and fcc Al was used to calculate the lattice constant and elastic constants of B2 FeAl and DO3 Fe3Al alloys. The formation energies of vacancy and antisite were also calculated. The present calculations are in agreement with the experimental data and the theoretical results obtained by other authors.展开更多
In this work,conductive polymer nanocomposites were developed based on a biodegradable and biobased polymer(poly(lactic acid)),with the incorporation of only 0.3 wt%of carbon nanotubes(CNTs)to be used as volatile solv...In this work,conductive polymer nanocomposites were developed based on a biodegradable and biobased polymer(poly(lactic acid)),with the incorporation of only 0.3 wt%of carbon nanotubes(CNTs)to be used as volatile solvent sensors.The correct dispersion of the nanofiller was achieved thanks to a CNT non-covalent modification with an azo-dye(disperse orange 3)which allowed to reach the percolation for electric conduction in values as low as 0.3 wt%.The chemo-resistive properties of the developed sensors were investigated by exposure to organic vapors(ethanol,tetrahydrofuran and toluene)and water vapor,showing good selectivity.In addition,considering the manipulation to which the sensor will be exposed,wear resistance was characterized,finding that the incorporation of CNTs produced an increase in more than a 50%.展开更多
文摘In this study, the structural, electronic and optical properties of DO3A-based boronic acid derivates with and without UO22+ ion are studied by density functional calculations with M062X/6 - 31 g + (d) method, in aqueous media. The quantum chemical properties such as EHOMO, ELUMO, the energy gap (ΔE), chemical potential (μ), hardness (η) are also performed. The theoretical essential UV-Vis. bands of DO3A-UO2(VI)-APB-o are at 392 and 687 nm. DO3A-UO2 (VI)-ABB-o structure has two main bands at 393 and 650 nm. In general, the bathochromic shift occurs and the HOMO-LUMO energy gap decreases to about 2 eV, by binding UO22+ ion in three different media. The notable shifts in NMR spectrums have been found on α-carbon of carbonyl group, ring carbons and amide protons. In IR-spectrums, the prominent peaks belong to BO-H and N-H of amide stretching vibrations of calculated structures.
文摘Copper-manganese-aluminum （CMA） alloys, containing small additions of Fe, Ni, and Si, exhibit good strength and remarkable corrosion resistance against sea water. The alloys are used in as-cast condition, and their microstructure can show wide variations. The morphology, crystallography and composition of the phases presented in an as-cast （CMA） alloy of nominal composition Cu-14%Mn-8%Al-3%Fe-2%Ni were investigated using optical, electron optical, and microprobe analytical techniques. The as-cast microstructure consisted of the grains of fcc α and bcc β-phases alongwith intermetallic precipitates of various morphologies. The room temperature microstructure exhibited four different types of precipitates inside the α-grains： the ＇large＇ dendritic-shaped particles and the cuboid-shaped precipitates, which were rich in Fe and Mn and had an fcc structure, while the ＇small＇ dendritic-shaped particles and the globular precipitates were based on FeaAI and had DO3 structure. These four different morphologies of intermetallic precipitates exhibited discrete orientation-relationships with the α-matrix. The β-grains only contained very small cuboid shaped precipitates, which could only be resolved through transmission electron microscopy. These precipitates were found to be based on Fe3Al and had the DO3 structure.
文摘A simple modified analytic EAM model for bcc Fe and fcc Al was used to calculate the lattice constant and elastic constants of B2 FeAl and DO3 Fe3Al alloys. The formation energies of vacancy and antisite were also calculated. The present calculations are in agreement with the experimental data and the theoretical results obtained by other authors.
文摘In this work,conductive polymer nanocomposites were developed based on a biodegradable and biobased polymer(poly(lactic acid)),with the incorporation of only 0.3 wt%of carbon nanotubes(CNTs)to be used as volatile solvent sensors.The correct dispersion of the nanofiller was achieved thanks to a CNT non-covalent modification with an azo-dye(disperse orange 3)which allowed to reach the percolation for electric conduction in values as low as 0.3 wt%.The chemo-resistive properties of the developed sensors were investigated by exposure to organic vapors(ethanol,tetrahydrofuran and toluene)and water vapor,showing good selectivity.In addition,considering the manipulation to which the sensor will be exposed,wear resistance was characterized,finding that the incorporation of CNTs produced an increase in more than a 50%.
