Materials Literature
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An in-situ modified sol–gel method for the preparation of a Ni-based monolith-supported catalyst is reported. With the presence of a proper amount of plasticizer and binder, and at an optimized pH value, the stable boehmite sol was modified with metal ions (Ni, Li, La) successfully without distinct growth of the parti…
In a bid to explore how the presence of electrolyte ions influence the friction experienced by hydrogen bonding and nonhydrogen bonding solute molecules, rotational dynamics of two structurally similar nondipolar probes, 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) and 1,4-dioxo-3,6-diphenylpyrrolo…
For an infinitely long bar with rectangular cross section 2a×2b and constant susceptibility χ in a uniform transverse applied field Ha along dimension a, the fluxmetric and magnetometric demagnetizing factors Nf,m as functions of a/b and χ are accurately computed using a finite-elements method. By comparison of the co…
Time-dependent density-functional theory (TDDFT) calculations were carried out to predict the Q-like bands of the two structural isomers of the phenylene-linked free-base (FBBC) and zinc (ZnBC) bacteriochlorin dimers. The calculated singlet excitation energies and oscillator strengths for the low-lying excited states…
Reaction of Na[N(CN)2] with CuSO4·5H2O and 2,5-Me2pyz produced {Cu2(2,5-Me2pyz)[N(CN)2]4}n (2,5-Me2pyz = 2,5-dimethylpyrazine), which is an unusual five-connected, two-fold interpenetrated network that orders antiferromagnetically at low temperature.
To date, the field of supramolecular chirality has attracted much attention in the scientific community, in the context of its direct connection with various natural systems and many practical applications in the areas of catalysis,[1] nonlinear optics,[2] polymer and materials science,[3] molecular recognition,[4] mo…
Structure and counterion diffusional mobility in simple models of solvent-free linear chain ionic heteropolymers has been investigated using molecular dynamics computer simulation. A generic coarse grain Kramers model was used in which a fraction f of charged monomers are distributed uniformly along the chains. Only e…
The magnetic and transport properties of as-deposited and long-aged La0.8Ca0.2MnO3−δ films have been investigated in a wide temperature range. The x-ray diffraction data have shown separation of the film into two crystalline phases of the cubic and rhombohedral symmetry with different oxygen contents of δ≃0.08 and 0.1…
Direct 1,4-conjugate addition of naked aldehydes to vinylketones is catalysed effectively by N-methyl-3-aminopropylated FSM-16 mesoporous silica, which can be regarded as a novel heterogeneous catalysis for a practical C-C bond formation reaction.
A systematic study on the formation and the stability of Al70Cu20Fe10 quasicrystalline alloy has been carried out through mechanical alloying. The influence of the milling parameters, sequence of additive elements, and heat treatment on the formation of icosahedral phase has been investigated through x-ray diffraction…
The thermal expansion coefficients of a single crystal and ceramic of Nb2O5 are measured in the temperature range of −200–500 °C by the dilatometer technique. Both single crystals and ceramics of Nb2O5 and Nb2O5(1−x):xTiO2 show negative thermal expansion in this temperature range. Some contribution to the result could…
Abstract A series of new aromatic polyamides having pendent naphthoxy groups were synthesized by the triphenyl phosphite‐activated polycondensation of (2‐naphthoxy)terephthalic acid (NOTPA) with various aromatic diamines in a medium consisting of N ‐methyl‐2‐pyrrolidone (NMP), pyridine, and calcium chloride. The diaci…
Thermoluminescence of Eu and Ce co-doped CaGa 2 S 4 has been investigated for the first time. All co-doped samples were found to exhibit a long afterglow of the Eu emission having a peak energy of ∼2.20 eV. Analyses of measured transient thermoluminescence curves showed two activation energies, ∼0.2 eV and ∼0.94 eV, f…
A hot isostatic pressing technique was used to prepare bulk polycrystalline samples of the hydrogen-absorbing materials LaAlxNi5−x. Ultrasonic methods were used to measure the elastic moduli of these alloys. Small corrections were made for porosity so that values expected for the theoretical density were found. The va…
A polymerizable complex (PC) technique was utilized to prepare fine powders of high purity BaTinO2n + 1 with n = 1, 2 and 5 at lower temperatures than those used for the ordinary solid-state reaction procedure. The formation of pure BaTinO2n + 1 occurred when precursors obtained from PC-derived gel materials were heat…
Emission enhancement from BaTiO3:Pr3+ by addition of trivalent ion under excitation above the fundamental absorption edge of BaTiO3 host crystals has been investigated. In this system, energy transfer occurs from BaTiO3 to Pr3+. Emission of Pr3+ is intensified by addition of small trivalent ions, e.g., Yb3+ or Sc3+, w…
We performed local density approximation (LDA)-based ab initio calculations for isolated substitutional donor impurities (phosphorus single donor and sulfur double donor), hydrogen at various sites, and hydrogen-related complexes (phosphorus-hydrogen and sulfur-hydrogen) in diamond. Their stable atomic configurations…
Infrared and Raman spectra of vermiculite clay have been recorded, and an assignment of the observed features in the spectra is proposed on the basis of molecular dynamics calculations. For this purpose, a force field yielding a structure and vibrational spectra in good agreement with the experimental data was develop…
The demagnetizing problem should be studied numerically in nonellipsoids with nonzero susceptibility χ, except for a few limiting cases where analytical treatment turns out to be practical. In this work, for an infinitely long bar with rectangular cross section 2a×2b and χ=∞ and −1 in a uniform transverse applied fiel…
The image contrast of a single-walled carbon nanotube (SWCNT) is investigated via high resolution transmission electron microscopy (HRTEM) experiments and image simulations. It is found that the common practice of determining the tube diameter by measuring the two dark lines in the HRTEM image of a SWCNT is not very a…