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。
Nitration of octafluoro[2.2]paracyclophane (OFP) provides an entry into the synthesis of a series of 11 monosubstituted OFPs, including the nitro, amino, chloro, bromo, iodo, hydroxy, and trifluoromethyl compounds. The NMR, mass spectrometric, and UV spectral properties of all of these derivatives are presented and di…
The authors have addressed the identification of molecular fossils of deoxophylloerythroetioporphyrin (DPEP) complexes of vanadium (V) and nickel (Ni) and its partitioning from crude oil into the environment. The analyses described here involve water/surfactant solutions that were in contact with the Boscan crude oil…
Two isostructural tellurium-rich tellurites, Na 2 WTe 4 O 12 ( 1 ) and Na 2 MoTe 4 O 12 ( 2 ), have been synthesized and structurally characterized by single-crystal X-ray diffraction studies. Three types of polyhedra, namely, MO 6 octahedra, TeO 3 pyramids, and TeO 5 square-pyramids, constitute the three-dimensional…
We analyze the Cerenkov emission of high-frequency confined acoustic phonons by drifting electrons in a quantum well. We find that the electron drift can cause strong phonon amplification (generation). A general formula for the gain coefficient, alpha, is obtained as a function of the phonon frequency and the structur…
Time-dependent properties of the speckled intensity patterns created by scattering coherent radiation from materials undergoing spinodal decomposition are investigated by numerical integration of the Cahn-Hilliard-Cook equation. For binary systems which obey a local conservation law, the characteristic domain size is…
Reaction of sodium azide with manganese(II) and pyridine derivatives such as 2-bzpy, 3-bzpy, and 3,5lut (2-benzoylpyridine, 3-benzoylpyridine, and 3,5-dimethylpyridine, respectively) led to the one-dimensional systems cis -[Mn(2-bzpy)(N 3 ) 2 ] n ( 1 ), trans -[Mn(3-Bzpy) 2 (N 3 ) 2 ] n ( 2 ), and cis- [Mn(3,5lut) 2 (…
As pointed out by Linus Pauling in his classic work on the relationship between crystal packing and ionic radius ratio, a difference in atomic size can be accommodated more readily by an ordered structure than by a disordered one. Because of mathematical complexity, however, very few works have been reported for subst…
We discuss the preparation of thin icosahedral films (Al-Cu-Fe and Al-Pd-Re) via the route of the amorphous (a-)phase which in some aspects is a precursor to the icosahedral phase. A direct transition from the a- to the i-phase occurs for Al-Cu-Fe films at 430 C on the time scale of minutes. The resulting films are of…
Amorphous samples of Al-Cu-Fe were crystallized to the icosahedral phase under the control of electrical conductivity and thermopower at a rather small temperature of T=720 K. A comparison between different annealing states of the amorphous and the resulting quasicrystalline phase done on the same sample shows aston-i…
Two recently commissioned infrared beamlines on the 1.4 bending magnet port at the Advanced Light Source, LBNL, are described. Using a synchrotron as an IR source provides three primary advantages: increased brightness, very fast light pulses, and enhanced far-IR flux. The considerable brightness advantage manifests i…
Intrinsic strain softening appears to be the main cause for the occurrence of plastic localization phenomena in deformation of glassy polymers. This is supported by the homogeneous plastic deformation behavior that is observed in polycarbonate samples that have been mechanically pretreated to remove (saturate) the str…
Cerium−zirconium mixed oxides (Ce x Zr (1 - x ) O 2 ), precalcined at 900 °C in dry air, were supplied by Rhodia Terres Rares as monophasic solid solutions. Introduction of some zirconium atoms in the ceria lattice by isomorphous substitution clearly influences the final properties of these materials as long as the cu…
One mechanism of silver resistance in microorganisms is accumulation of the metal ions in the cell. Here, we report on the phenomenon of biosynthesis of silver-based single crystals with well-defined compositions and shapes, such as equilateral triangles and hexagons, in Pseudomonas stutzeri AG259. The crystals were u…
Effect of poling on surface crystallization behavior of BaTiO3 in 15BaO–15TiO2–70TeO2 glass and on second-harmonic generation of the resultant glass ceramics has been examined. A direct current voltage in a range of 0.3–1 kV was applied to the original glass at around 400 °C, which is above its glass transition temper…
Both the “after-pulse effect” and the dynamic characteristics of photostructural transformations induced in glassy As0.5Se0.5 films by pulsed 532 nm excitation have been studied. The after-pulse effect investigation demonstrated more than a 103 times increase of the photosensitivity in case of pulsed excitation. Dynam…
Certain spin Hamiltonians that give rise to tunnel splittings that are viewed in terms of interfering instanton trajectories are restudied using a discrete WKB method, that is more elementary, and also yields wave functions and preexponential factors for the splittings. A novel turning point inside the classically for…
We have measured the deposition of potential energy of slow $(\ensuremath{\sim}6\ifmmode\times\else\texttimes\fi{}{10}^{5}\mathrm{m}/\mathrm{s})$, highly charged ions in solids with an ion implanted silicon detector. A large fraction (about $35%$ or 60 keV) of the potential energy dissipated by ${\mathrm{Au}}^{69+}$ i…
We report on the effect of pressure on the dual segmental relaxation of an athermal poly(isoprene-b-vinylethylene) (PI-PVE) diblock copolymer melt using dielectric spectroscopy. The quantity (∂ log τ/∂P)T is employed as a probe of the state of dynamic miscibility in the system. We find that pressure, unlike temperatur…
The nature of ion diffusivity in the vitreous conductor $2\mathrm{Ca}({\mathrm{NO}}_{3}{)}_{2}\ifmmode \dot{}\else \.{}\fi{}3{\mathrm{KNO}}_{3}$ (CKN) was studied by nonresonant dielectric hole burning. Spectral holes in the electric field relaxation are probed subsequent to a high electric sinusoidal burn field. For…
Low temperature properties of glasses are derived within a generalized tunneling model, considering the motion of charged particles on a closed path in a double-well potential. The presence of a magnetic induction field $\mathit{B}$ violates the time reversal invariance due to the Aharonov-Bohm phase, and leads to flu…