Materials Literature
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We present the structure-dependent nonlinear optical (NLO) properties of fully conjugated tri(perylene bisimides) (triPBIs) toward the understanding of the role of conformational flexibility and pi-electron conjugation in molecular NLO properties of model graphene-nanoribbon (GNR)-like molecules. In the present paper,…
Ceramers constitute a new type of porous hybrid ceramic which is obtained by pyrolysis of polysiloxane precursors with organic side groups at temperatures low enough that part of the polymer has not yet been decomposed (≈500 °C). By using different precursors, interesting possibilities arise to change the structural a…
Silk fiber-reinforced polypropylene (PP) matrix composites were prepared by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus, impact strength (IS), and hardness of the prepared composite (20 wt%) were found to be 54.7 MPa, 1826.2 MPa, 58.3 MPa, 3750.7 MPa, 17.6 kJ/m 2 , and 95,…
Reactions between molybdenum suboxide cluster anions, Mo(x)O(y)(-) (x=1-4; y < or = 3x), and water (H(2)O and D(2)O) have been studied using mass spectrometric analysis of products formed in a high-pressure, fast-flow reactor. Product distributions vary with the number of metal atoms in the cluster. Within the MoO(y)(…
Defined perpendicular anisotropy gradients in the Co sublayers of a [Co(0.6 nm)/Au(2 nm)](3) sputter-deposited multilayer have been introduced by light ion bombardment through a wedged Au stopper layer. Within such a layer system, domain walls between up- and down-magnetized areas are controllably movable by an extern…
Four different‐sized pure Al powders were used to react with distilled water at 55°C in a low vacuum, and their effect on the reaction dynamics and hydrogen‐generation rate was investigated. It was found that the Al particle sizes not only affect the hydrogen‐generation rate but also affect the induction time for the…
This paper investigates the energy transfer of Sm 3+ →Eu 3+ in (Ca, Ba) 3 (VO 4 ) 2 :Sm 3+ , Eu 3+ phosphors. The multipolar mechanism of energy transfer (Sm 3+ →Eu 3+ ) was found to be dipole–quadrupole. The energy transfer efficiency and possibility were calculated according to the emission intensity and lifetime of…
Precision dendrimer: Nine different dendrimer components with precise numbers of a functional ligand were isolated leading to an order of magnitude improvement in the purity of each component.
Molecular models of gelatin-based materials formed the basis for the knowledge-based design of a physically cross-linked polymer system. The computational models with 25 wt.-% water content were validated by comparison of the calculated structural properties with experimental data and were then used as predictive tool…
We address recent experiments (Science 2009, 325, 1367) reporting on highly efficient multiplication of electron-hole pairs in carbon nanotube photodiodes at photon energies near the carrier multiplication threshold (twice the quasi-particle band gap). This result is surprising in light of recent experimental and theo…
The defect structure of Fe(3+)-, Cu(2+)-, Mn(4+)- and Gd(3+)-doped PbTiO(3) nano-powders has been studied by electron paramagnetic resonance (EPR) spectroscopy. Analogous to the situation for 'bulk' ferroelectrics, Fe(3+) and Cu(2+) act as acceptor-type functional centers that form defect complexes with charge-compens…
Abstract A simple, facile and versatile approach is presented for the preparation of PMMA/ZnO nanocomposite materials, which possess high transparency, no color, good thermal stability, UV absorption and improved mechanical properties. The employed process involved mixing of ZnO nanoparticles dispersed in DMAc with th…
We examined non-stoichiometric CaAl(x)Si((7-3x)/4)N(3):Eu(2+) phosphors that were intentionally prepared with x = 0.7-1.3 to identify the origin of the deconvoluted Gaussian components that constitute the emission spectra of stoichiometric CaAlSiN(3):Eu(2+) phosphors. The Al/Si molar ratio around the Eu(2+) activator…
In this paper we demonstrate that the Kubas interaction, a nondissociative form of weak hydrogen chemisorption with binding enthalpies in the ideal 20-30 kJ/mol range for room-temperature hydrogen storage, can be exploited in the design of a new class of hydrogen storage materials which avoid the shortcomings of hydri…
Ferromagnetic ordering at room temperature (RTFM) in MgO thin films deposited by RF magnetron sputtering under various atmospheric conditions and temperatures is reported. A saturation magnetization (M(S)) value as high as 1.58 emu g(-1) is (0.046 μB/unit cell) observed for a 170 nm film deposited at RT under an oxyge…
Hyper-Raman spectra for pyridine and pyridine on the surface of a tetrahedral 20 silver atom cluster are calculated using static hyperpolarizability derivatives obtained from time dependent density functional theory. The stability of the results with respect to choice of exchange-correlation functional and basis set i…
By performing density functional theory calculations, we show the mechanism details of CO oxidation catalyzed by several Pt m Au n ( m + n = 4) clusters. It is found that in all situations, the reaction prefers to proceed via the single-center pathway to the two-center pathway according to a two-step mechanism: the in…
A novel method is reported for the preparation of transparent polycrystalline yttria ceramics in oxygen atmosphere. Zirconia and other additives were added to control the grain growth. Pores can be eliminated clearly at a temperature <1650°C with the grain size around 1 μm. The grain growth kinetics and the mechani…
The spatial distribution of photocurrents generated in nanoscale devices comprising a contact between a graphene sheet and a cadmium sulfide nanowire is explored. The magnitude and spatial extent of the photocurrent can be improved through appropriate chemical modification of the graphene–CdS interface. Moreover, the…
The effect of electron-impurity and electron-electron interactions on the energy spectrum of electrons moving in graphene is investigated in the presence of a high magnetic field. We find that the width of the broadened Landau levels exhibits an approximate $1/B$ dependence near half filling for charged impurity scatt…