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。
Sustained photogeneration of hydrogen was observed on metal~free as well as on platinized SrTi0 3 single crystals illuminated in aqueous alkaline electrolytes or in the presenee of electrolyte films.Hydrogen evolution rates increased with eleetrolyte hydroxide concentration) most strongly at hydroxide concentrations a…
Abstract Allophane samples from soils, pumice, and stream beds have been studied by electron optical, infrared absorption, X-ray fluorescence, gas chromatography, and phosphate adsorption methods. The allophane particles were hollow spherules or polyhedra 35 and 50 Å in diameter with molar Al/Si ratios close to 2.0. T…
The sintering behavior of binary ZnO ceramics (containing 0.01–1 mol% of added Bi2O3) showed that densification in the initial stage of sintering and grain growth of the ZnO matrix are enhanced in the presence of a liquid Bi2O3 phase. Exaggerated grain growth of ZnO was observed above 1100 °C and in mixtures containin…
At normal temperatures and pressures water is known to have a strong influence on the strength of ceramics and glasses. Behaving as a stress corrosion agent, water causes these materials to fail prematurely as a consequence of subcritical crack growth. A basic premise of this paper is that stress corrosion cracking of…
Abstract Current theories on the origin of high electrical conductivity in TCNQ-based materials emphasize the need for incomplete charge transfer as well as segregated stacks of donor and acceptor molecules and uniform spacing within the stacks. The requirements for an “organic metal” are discussed in terms of partial…
Abstract The tensile behavior of blends of linear polyethylene (PE) and isotactic polypropylene (PP) was examined in relation to their morphology. Yield stress increases monotonically with increasing PP content, while true ultimate strength is much lower in all blends than in the pure polymers as a result of early fra…
Following the structure analysis of uranocene, U(C{sub 8}H{sub 8}){sub 2}, we found to our surprise that almost nothing was known about the structure and bonding of organoactinides and lanthanides - a situation we have endeavored to change during the intervening years. The reported synthesis of uranocene in 1968 by Mu…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotoresponsive crown ethers. 1. Cis-trans isomerism of azobenzene as a tool to enforce conformational changes of crown ethers and polymersSeiji Shinkai, Takahiro Nakaji, Yoshihiro Nishida, Toshiyuki Ogawa, and Osamu ManabeCite this: J. Am. Chem. Soc. 1980, 102, 18, 5860–586…
Abstract not Available.
Abstract An analysis is given of the well‐known Moss formula connecting the energy gap to the refractive index of semiconductors. Based on Penn's model for the dielectric function of semiconductors and the treatment of Wemple, the refractive index is related to the energy gap. For small gaps, the relation is shown to…
The corrosion of iron in bicarbonate solutions has been investigated potentiostatically and by Auger electron spectroscopy. The dissolution of iron in the active and prepassive regions is greatly accelerated by the presence of bicarbonate, owing to the formation of the stable soluble complex anion Fe(CO3)22-. A mechan…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA semiclassical treatment of electron-exchange reactions. Application to the hexaaquoiron(II)-hexaaquoiron(III) systemBruce S. Brunschwig, Jean Logan, Marshall D. Newton, and Norman SutinCite this: J. Am. Chem. Soc. 1980, 102, 18, 5798–5809Publication Date (Print):August 1,…
Approximate methods are used to calculate the growth of grain-boundary cavities by power-law creep, under multi axial stress states. The time to fracture at constant stress is given by t f =t n+ɑ/n+1)εss1n(1/(n+1)f i )where t n is the nucleation time (the time at which the voids first appear), εss is the steady-state…
In Pb(Sc0.5Ta0.5)O3 it has been shown that the degree of order in the B-site Sc3+, Ta5+ cations can be controlled by suitable thermal annealing. For samples which have been well-ordered by long annealing, dielectric measurements on single crystals show a normal first-order ferroelectric phase change at 13 °C and a max…
A new equation is derived for large amplitude forced radial oscillations of a bubble in an incident sound field. It includes the effects of acoustic radiation, as in Keller and Kolodner’s equation, and the effects of viscosity and surface tension, as in the modified Rayleigh equation due to Plesset, Noltingk and Neppi…
We assess various approximate forms for the correlation energy per particle of the spin-polarized homogeneous electron gas that have frequently been used in applications of the local spin density approximation to the exchange-correlation energy functional. By accurately recalculating the RPA correlation energy as a fu…
International audience
High-pressure x-ray scattering studies of $2H$-Ta${\mathrm{Se}}_{2}$ reveal reentrant behavior of the charge-density-wave (CDW) lock-in transition. As pressure is increased the normal-to-incommensurate CDW transition changes less than 5 K; however, the lock-in transition, initially suppressed to $T\ensuremath{\rightar…
The infrared absorption from molecular monolayers is enhanced a factor of 20 by thin metal overlayers or underlayers with use of the attenuated-total-reflection technique. The total enhancement, including contributions from the attenuated-total-reflection geometry, is almost ${10}^{4}$. This effect is consistent with…
Dielectric constant (K), loss (tan δ), and conductivity (σ) of single crystals of PbI2 are measured (E ∥ c-axis) as a function of frequency in the range 102 to 107 Hz and at temperatures between 77 to 560 K. At room temperature (≈︁ 303 K), the K-value at 106 Hz is 6.7. The dielectric constant of this crystals increase…