The site distribution of Ti and V and the metal-metal interaction in the ternary system (V,Ti)5S8

The phase relations of the ternary system V_1?xTi_xS_1.57 are presented on the basis of X-ray diffractometry. The site distribution of Ti and V atoms in the structure is clarified through an NMR absorption study at room temperature. The phase relations and the site distribution of Ti and V, which appear to be closely related to each other, are discussed in terms of the metal-metal interaction of the face-shared octahedra in the metal-deficient distorted NiAs structure.     

Vapor-liquid equilibria for polyisobutylene solutions

Vapor sorption isotherms in binary solutions of polyisobutylene (PIB), (M_η = 4.7 × 10⁶ g/mol) in hydrocarbons (cyclopentane; cyclohexane; n-heptane; 2,2-dimethyl butane; and 2,2,4-trimethyl pentane) and chlorinated methanes [carbon tetrachloride (CCI₄) and chloroform (CHCI₃)] have been determined at 23.5°C using the piezoelectric sorption method. The polymer-solvent interaction parameter χ obtained agrees with previously published values determined by using gas-liquid chromatography and a quartz-helix vapor sorption apparatus. The Flory theory of corresponding-states has been applied to the experimental results through the χ parameter and affords a good prediction of the concentration dependence of χ for solutions of chloroform, carbon tetrachloride, n-heptane, and 2,2-dimethyl butane in PIB. The experimental values of \documentclass{article}\pagestyle{empty}\begin{document}$ [\partial (a_1 /\psi _1 )/\partial a_1 ]_{T,P} $\end{document} for the PIB solutions are constant over the measured concentration range, for example \documentclass{article}\pagestyle{empty}\begin{document}$ [\partial (a_1 /\psi _1 )/\partial a_1 ]_{T,P} $\end{document} = ?4.1 for CCI₄, ?3.65 for CHCI₃, ?3.0 for 2,2-dimethyl butane and n-heptane, ?2.7 for 2,2,4-trimethyl pentane, ?2.7 for cyclohexane, and ?1.7 for cyclopentane, where a₁ is the solvent activity and ψ₁ is the solvent segment fraction. The correlations between the values of \documentclass{article}\pagestyle{empty}\begin{document}$ [\partial (a_1 /\psi _1 )/\partial a_1 ]_{T,P} $\end{document} and the theories of Guggenheim, Miller, Huggins, and Flory are discussed.     

Non-equilibrium thermo-field dynamics for a non-bilinear Hamiltonian

The non-equilibrium thermo-field dynamics proposed by Arimitsu and Umezawa are generalized to the case of a non-bilinear unperturbed Hamiltonian which includes not only a bilinear part but also a non-bilinear part with momentum mixing. The forms of the quasi-particle operators for a semi-free boson field are derived. The form of the two-point Green’s function for the semi-free boson field is evaluated. A form of the admittance for a boson system interacting with its heat reservoir, which includes effects of the initial correlation and memory, is derived using the TCLE method formulated in terms of generalized non-equilibrium thermo-field dynamics. The expressions of the zeroth-order, first-order and second-order parts of the admittance in powers of the boson-boson interaction, are derived.     

Quantitative analysis of ethanol–methanol–water ternary solutions using Raman spectroscopy

Raman spectroscopy was used for rapid in-situ measurement of alcohols in ethanol-methanol-water ternary systems. Mass fractions of the individual components were determined using calibration curves for binary systems of ethanol-water, methanol-water, and ethanol-methanol. Calibration curves were constructed by calculating the ratio of the Raman peak intensity of a component and that of an external standard (acetonitrile). Assuming additivity of the spectra, simultaneous equations were written, and mass fractions of ethanol, methanol, and water in the ternary solutions were determined by solving the system of equations through calculating an inverse matrix. The relative errors between the mass fractions obtained from the Raman spectra and those obtained from mass measurements were <0.6%.     

Hooking Together Sigmoidal Monomers into Supramolecular Polymers

Supramolecular polymers show great potential in the development of new materials because of their inherent recyclability and their self‐healing and stimuli‐responsive properties. Supramolecular conductive polymers are generally obtained by the assembly of individual aromatic molecules into columnar arrays that provide an optimal channel for electronic transport. A new approach is reported to prepare supramolecular polymers by hooking together sigmoidal monomers into 1D arrays of π‐stacked anthracene and acridine units, which gives rise to micrometer‐sized fibrils that show pseudoconductivities in line with other conducting materials. This approach paves the way for the design of new supramolecular polymers constituted by acene derivatives with enhanced excitonic and electronic transporting properties.     

Local structural analysis of In-doped Bi2Se3 topological insulator using X-ray fluorescence holography

We performed X-ray fluorescence holography measurements on an In-doped Bi₂Se₃ topological insulator and obtained an in-plane atomic image in the vicinity of In. We found that atomic images at the positions of the first nearest neighbors (NNs) are very weak whereas those at the positions of the second and the third NNs are relatively strong. On the basis of the fact that In is half of the atomic number of Bi, we attributed the origin of this feature to the clustering of the In atoms in the Bi plane. We calculated the intensity of the atomic images and confirmed that the formation of In cluster results in a decrease by 30% in the first NN atomic image intensity. However, the decrease in the magnitude is not enough to explain the experimental results, suggesting another contribution such as the lattice distortions. The effect of the lattice distortion on the atomic image intensity is discussed on the basis of the simulation including the positional fluctuation of In atoms.     

Neutron activation analysis of carbonate reference materials: coral (JCp-1) and giant clam (JCt-1)

Journal of Radioanalytical and Nuclear Chemistry - Two kinds of carbonate reference materials, coral (JCp-1) and giant clam (JCt-1), were subjected to neutron activation analysis (NAA) using the...     

Formation of an Azaruthenacyclopentadiene Skeleton via Ammonia Activation by an Electron-Deficient Ru3 Cluster

A dicationic triruthenium complex containing a μ₃-η³-C₃ ring, [(Cp*Ru)₃(μ₃-η³-C₃MeH₂−)(μ₃-CH)(μ-H)]²⁺ ( 1 a , Cp*=η⁵-C₅Me₅), reacted with ammonia to yield a μ-amido complex, [(Cp*Ru)₃(μ₃-η³-CHCMeCH) (μ₃-CH)(μ-NH₂)]²⁺ ( 5 ), via N−H bond scission. Subsequent treatment with base resulted in C−N bond formation to yield a μ₃-η²:η²-1-azabutadien-4-yl complex, [(Cp*Ru)₃(μ₃-CH)(μ₃-η²:η²-NH=CH−CMe=CH−)]⁺ ( 6 a ). The azaruthenacyclopentadiene skeleton was alternatively synthesized by the photolysis of mono-cationic complex [(Cp*Ru)₃(μ₃-η³-C₃RH₂−)(μ₃-CH)]⁺ ( 2 a ; R=Me, 2 b ; R=H) in the presence of ammonia. The C₃ ring skeleton was broken via the electron transfer to the π*(C−C) orbital in the C₃ ring, and a transiently generated unsaturated μ₃-allylic species can take up ammonia, resulting in N−H bond scission followed by C−N bond formation.