Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
In this paper we propose an improved three-dimensional (3D) boundary charge method (BCM) for a composite dielectric system in which insulators, i.e., dielectric materials exist together with conducting electrodes. The method is based on the idea that the composite dielectric system can equivalently be replaced with a…
Organic–inorganic hybrids of a cross-linked polyimide and silica were prepared via the sol–gel route using an acetylene-terminated oligomeric isoimide and tetraethoxysilane (TEOS) precursors. Two coupling agents, γ-mercaptopropyltrimethoxysilane (MPTMS), and triethoxysilane were employed to compatibilise the organic a…
Halohydrin dehalogenases are key enzymes in the bacterial degradation of vicinal halopropanols and structurally related nematocides. Crystals of the enantioselective halohydrin dehalogenase HheC from Agrobacterium radiobacter AD1 have been obtained at room temperature from hanging-drop vapour-diffusion experiments aga…
The de novo phasing of the structures of two crystal forms of tryparedoxin II from Crithidia fasciculata has been carried out using single-wavelength anomalous diffraction techniques exploiting only the small anomalous signal from the S atoms intrinsic to the native protein. Data were collected at 1.77 A wavelength, w…
tert -Butoxygallane, [tBuOGaH 2 ] 2, reacts with tetraphenyl-1,3-disiloxanediol, HO(Ph 2 )Si−O−Si(Ph 2 )OH, with hydrogen elimination to form the bicyclic compound [(OSiPh 2 OSiPh 2 O)[Ga(H)] 2 (OtBu) 2 ] ( 1 ). The skeleton of molecule 1 consists of a four-membered Ga 2 O 2 ring to which a five-membered O−Si−O−Si−O b…
The recombinant catalase-peroxidase of Synechococcus PCC 7942 overexpressed in Escherichia coli was purified and crystallized by the hanging-drop vapour-diffusion method using sodium formate as a precipitant. The crystals belonged to the tetragonal space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell parameters a = b…
A neutral gadolinium complex, Gd-HPDO3A, is shown to be a good candidate to use to obtain heavy-atom derivatives and solve macromolecular structures using anomalous dispersion. Tetragonal crystals of a gadolinium derivative of hen egg-white lysozyme were obtained by co-crystallization using different concentrations of…
We show here how a Ru(bpy)2(CE-bpy) complex can be used for the ECL detection of sodium ion in both aqueous and nonaqueous media. Recognition of Na+ by the crown ether moiety in CE-bpy results in a significant increase in the ECL emission intensity of the complex.
A 3-D network polymer, Mn(NITpPy)2(tp)(H2O)2, has been synthesized and structurally and magnetically characterized. In the crystal structure, the 1-D chains are formed by [Mn(NITpPy)2]2+ units and terephthalate ligands, and they are linked together by hydrogen bonds to give rise to a 3-D network. Magnetic measurements…
Photocoloration of microcrystalline powder of spirooxazine and spiropyran compounds induced by femtosecond laser excitation was investigated using time-resolved and steady state diffuse reflectance spectroscopy. The intermediate products were observed in a ns time region, and assigned to non-planar open forms. On the…
Swelling of poly(methyl methacrylate) and poly(butyl methacrylate) samples in supercritical carbon dioxide and propagation of diffusion fronts in the samples were studied in situ at various temperatures and pressures using direct optical observation. The difference in the appearance of diffusion fronts in these polyme…
A new class of diblock copolymers was synthesized from biodegradable poly(lactic acid) and poly(ethylene glycol)minus signmonoamine. These polymers were activated by covalently attaching linkers such as disuccinimidyl tartrate or disuccinimidyl succinate to the hydrophilic polymer chain. The polymers were characterize…
Oxidative polymerization of bisphenolic monomers has been performed using peroxidase as catalyst in an aqueous organic solvent. Peroxidase induced the polymerization of an industrial product, bisphenol F, consisting of 2,2'-, 2,4'-, and 4,4'-dihydroxydiphenylmethanes. Under the selected conditions, the quantitative fo…
The serum transferrins are monomeric proteins with a molecular mass of around 80 kDa and are responsible for the transport of iron in vertebrates. The three-dimensional structures of diferric porcine and rabbit serum transferrin have been refined against X-ray diffraction data extending to 2.15 and 2.60 A, respectivel…
The phase behavior of polystyrene−polyisoprene diblock copolymers diluted with solvents strongly selective for polyisoprene was investigated using variable-temperature small-angle X-ray scattering. Tetradecane was employed as a model selective solvent; its addition induced lyotropic order−order transitions, with as ma…
Powder diffraction patterns of ordered mesoporous materials are simulated with a newly developed program, which allows investigation of the influence of any desired matter distribution in the unit cell on the diffraction pattern. The simulation process can be subdivided into two major steps. First, a unit cell is gene…
In this paper we show that 1-electron properties such as Compton profiles and structure factors of crystals can be asymptotically retrieved through cluster-based calculations, followed by an appropriate partition of the 1-electron reduced density matrix (1RDM). This approach, conceptually simple, is checked with respe…
A theory for the reliable prediction of the EPR g-tensor for paramagnetic defects in solids is presented. It is based on density functional theory and on the gauge including projector augmented wave (GIPAW) approach to the calculation of all-electron magnetic response. The method is validated by comparison with existi…
This paper shows that the phenomenon of orbital ordering should be detectable by energy-filtered quantitative convergent-beam electron diffraction (QCBED). The structure factors of LaMnO(3) crystals are calculated using a non-spherical atomic scattering model of the Mn(3+) ion. Several low-order electron structure fac…
In the present study, we investigated the effects of annealing of amorphous hydrogenated carbon (a-C:H) films, particularly with respect to structural changes of the carbon network and their impact on the hydrogen-atom-induced erosion. The a-C:H films were deposited at 300 K on a Pt(111) single crystal using the ion-b…