Materials Literature
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A first-principles quantum chemistry method, based on the Kohn-Sham density-functional theory, is used to investigate the adsorption of CO and O2 on small gas-phase gold cluster anions. The saturated adsorption of carbon monoxide on gold cluster anions AuN- (N=2-7) is discussed. The adsorption ability of CO reduces wi…
We directly visualize single polymers with persistence lengths l(p), ranging from 0.05 to 16 microm, dissolved in the nematic phase of rodlike fd virus. Polymers with a sufficiently large persistence length undergo a coil-rod transition at the isotropic-nematic transition of the background solvent. We quantitatively a…
The photoluminescence quantum efficiency of semiconductor nanocrystals at room temperature was markedly enhanced about 50 times by surface treatment of the nanocrystals after synthesis, and the original photoluminescence peak position and narrow line width were maintained. Simply, the nanocrystal surface was treated w…
There are many technological applications using thin polymer films that would be crucially influenced by confinement-induced changes in the transport properties of the film. In the present, we utilize specular X-ray reflectivity (SXR, to measure film thickness h ), beam positron annihilation lifetime spectroscopy (PAL…
Mo takes the tube: A saddle-distorted MoV–porphyrin complex forms a tubular assembly through intermolecular π–π interactions, which has an internal diameter of 1 nm (see picture). Within such tubes, tetranuclear MoVI–oxo clusters could be size-selectively included through intermolecular hydrogen-bonding interactions.
We recently developed several methods to enhance the cell-polymer interactions. Optimal conditions for each method have been revealed separately by in vitro cell culture. As a practical consideration for construction of tissue-engineered organs, it is necessary to consider which is the most suitable and convenient in…
Experimental and theoretical evidence is presented for the nondissociative chemisorption of O2 on free Au cluster anions (Aun-, n=number of atoms) with n=2, 4, 6 at room temperature, indicating that the stabilization of the activated di-oxygen species is the key for the unusual catalytic activities of Au-based catalys…
Calcium carbonate was precipitated from calcium hydroxide and carbonic acid solutions at 25 degrees C, with and without addition of different magnesium (MgSO(4), Mg(NO(3))(2) and MgCl(2)) and sodium salts (Na(2)SO(4), NaNO(3) and NaCl) of identical anions, in order to study the mode of incorporation of magnesium and i…
We use first-principles calculations for transition-metal impurities V, Cr, Mn, Fe, Co, and Ni in GaAs, as well as Cr and Mn in GaN, GaP, and GaSb, to identify the basic features of the electronic structures of these systems. The microscopic details of the hole state such as the symmetry and the orbital character, as…
A cluster-forming ligand, p-tert-butylsulfonylcalix[4]arene (H4L), allows the formation of lanthanide wheels whose cluster cores contain eight lanthanide ions (GdIII, SmIII, NdIII, or PrIII; shown in green in the picture) connected by L4− ions, which act as both a tetradentate and a bisbidentate μ3-ligand, and eight b…
Composition, crystal structure, and stability of the thermoelectric material, known in the literature as “Zn 4 Sb 3 ”, has been characterized using low- and room-temperature single-crystal X-ray diffraction techniques, as well as in situ room- and high-temperature powder X-ray diffraction methods. We have found that t…
The bond-order potential (BOP) for transition metals is a real-space semiempirical description of interactions between the atoms, which is based on the tight-binding approximation and the d-band model. This scheme provides a direct bridge between the electronic level modeling and the atomistic modeling, where the elec…
For carbon nanotubes, we determine the role of disorder and helicity in the transport length scales and intrinsic conductance. Our results highlight different physical phenomena originating from defect scattering and multishell conduction. Those effects are sensitive to the position of the Fermi level, and allow for a…
Unprecedented 18‐molybdosulfite Dawson clusters encapsulate two pyramidal sulfite ions as templates, and exhibit a short S⋅⋅⋅S interaction between the two ions, which was characterized by DFT calculations. The [Mo 18 O 54 (SO 3 ) 2 ] 4− ion is the first discrete thermochromic polyoxometalate cluster: its color varies…
We report the first direct observation of ferromagnetic spin polarization of Au nanoparticles with a mean diameter of 1.9 nm using X-ray magnetic circular dichroism (XMCD). Owing to the element selectivity of XMCD, only the gold magnetization is explored. Magnetization of gold atoms estimated by XMCD shows a good agre…
A many-body theory approach is developed for the problem of positron-atom scattering and annihilation. Strong electron-positron correlations are included non-perturbatively through the calculation of the electron-positron vertex function. It corresponds to the sum of an infinite series of ladder diagrams, and describe…
An ab initio structure optimization technique is newly developed to determine the valley line on a total-energy surface for zone-center distortions of ferroelectric perovskite oxides and is applied to barium titanate BaTiO3 and lead titanate PbTiO3. The proposed technique is an improvement over King-Smith and Vanderbi…
Efficient photocyclization from a low-lying triplet state is reported for a photochromic dithienylperfluorocyclopentene with Ru(bpy)3 units attached via a phenylene linker to the thiophene rings. The ring-closure reaction in the nanosecond domain is sensitized by the metal complexes. Upon photoexcitation into the lowe…
Cerium oxide nanoparticles ${\mathrm{CeO}}_{2\ensuremath{-}x}$ (\ensuremath{\sim}3--20 nm in diameter) made by a vapor phase condensation method, have been studied by several methods of transmission electron microscopy (TEM): electron energy loss spectroscopy (EELS), high resolution imaging, and electron diffraction.…
Non-liner behavior of dissipation current that flows in polymer materials contains much information about dielectric property under AC high field application. Recently, the properties were evaluated by using film sample of non-polar dielectric materials. AC dissipation current measurement shows the formation of AC spa…