Materials Literature
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Fine structures in electron energy-loss spectra, observed 30-40 eV beyond the threshold of oxygen K-edges in perovskite-type manganites BiMnO3 and LaMnO3, are discussed. LaMnO3 with orthorhombic symmetry (space group Pbnm) shows a clear peak in this region. However, BiMnO3 with a heavily distorted perovskite-type stru…
Der Zusammenhalt von Riesenvesikeln kann durch Substanzen wie Poly-L-lysin (kationisch), Polyvinylpyrrolidon (nichtionisch) und Heparin (anionisch) gefördert oder verhindert werden. Dies lässt sich mikroskopisch verfolgen; bei einem elektrostatisch zusammengehaltenen Paar von Vesikeln erwies sich die Adhäsion als zeit…
CuS 2 and CuSe 2 with pyrite structures were systematically studied by transport, magnetization, and specific-heat measurements. In remarkable contrast to other 3d transition-metal pyrites, a clear indication of strong electron correlations was absent in the electronic properties of Cu pyrites. We interpret this as a…
Ein Back-to-Front-Ansatz für die Synthese von Azuliporphyrinen aus einem Azulipyrran 1 wurde entwickelt. Mit dieser Methode gelang erstmals die rationale Synthese des Dicarbaporphyrinoids 2.
Abstract New phenolic hydroxyl‐pendant aromatic polyimides were synthesized with the N ‐silylated diamine method in two steps: the ring‐opening polyaddition of tetrakis(trimethylsilyl)‐substituted 4,4′‐diamino‐3,3′‐dihydroxybiphenyl to various aromatic tetracarboxylic dianhydrides, giving trimethylsiloxy‐pendant poly(…
The cooling effect of an ambient gas on arc discharge for the growth of carbon nanotubes has been investigated in terms of the diameter of the nanotube. A small diameter nanotube with high purity is successfully obtained by cooling of ambient He gas using a water-cooling coil placed around the arc discharge. Furthermo…
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…