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。
Cohesive zone models provide an illuminating and tractable way to include constitutive nonlinearity into continuum models of defects. Powerful insights have been gained by studying both dislocations and cracks using such analyses. Recent work has shown that as a result of the locality assumption present in such cohesi…
In the present paper, the dielectric behaviour of the PbLixNb3xZr0.51Ti0.49-4xO3 ( PLNZT) system is analyzed. It is shown that the decrease in the dielectric constant with respect to an increase of the impurity content may be due to an aggregation trend of the interacting off-centre dipoles rather than due to cooperat…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTA Practical Method for Epoxidation of Terminal Olefins with 30% Hydrogen Peroxide under Halide-Free ConditionsKazuhiko Sato, Masao Aoki, Masami Ogawa, Tadashi Hashimoto, and Ryoji NoyoriView Author Information Department of Chemistry and Molecular Chirality Research Unit, Nagoy…
A kind of nano-amorphous thin film was prepared by RF sputtering. The results of XRD and HREM analysis showed that the film was mainly composed of nano-amorphous particles sized about 10 nm on average. The electrical conductivity was measured using an AC impedance technique in the temperature range 283 - 373 K. It was…
Previously, we discussed a purely classical model for analysing surface plasmons of the molecule. The molecule was described as an abrupt spherical shell containing an effective number of or electrons. This simple model was found to be quite applicable for analysis of electron energy loss spectra (EELS), describing th…
We used electrochemical impedance spectroscopy (EIS) to investigate microbial degradation of polyimides used as insulators in electronic packaging. The microbial inoculum was a fungal consortium isolated from degraded polyimides. Microorganisms grew on these polymers yielding distinctive EIS spectra indicative of fail…
A recently developed electro-optical Pockels effect technique, which allows the dynamic measurement of surface charge distributions, is employed to observe the dynamic behaviour of a partial discharge in a point - dielectric gap. One period of an 8 kV ac voltage is applied to a needle electrode with gap spacings rangi…
We have investigated the partial discharge (PD) due to electrical treeing degradation in low-density polyethylene (LDPE), ethylene - vinyl acetate copolymer (EVA) and ethylene - acrylic acid copolymer (EAA) by a computer-aided partial discharge measurement system which allowed us to obtain phase-resolved PD pulse data…
This review deals with the definition and development of hard magnetic materials with special emphasis on more recent developments in this field. After discussing the fundamental properties of all hard magnetic materials, based on the intrinsic and extrinsic properties, some remarks on the history of hard magnetic mat…
Carbon nanotubes have been opened using a variety of oxidants including and at room temperature. The opened nanotubes have been filled with metals such as Ag, Au, Pd and Pt by simple chemical means. The opened nanotubes, containing a high concentration of acidic functional groups, get covered or closed by reaction wit…
Diamond nanoparticles synthesized by the detonation of explosives were used as an additive in paraffin oil. The tribological properties of the two-phase lubricant of paraffin oil and diamond nanoparticles were investigated. The results show that, under boundary lubricating conditions, this kind of two-phase lubricant…
The crystallization kinetics of poly(L-lactide-co-meso-lactide) were determined over a range of 0% to 9% mesolactide. The kinetics were fit to the nonlinear Avrami equation and then to the Hoffman–Lauritzen equation modified for optical copolymers. The theory was found to fit the data well. The crystallization half-ti…
There are 590,232 federally reported bridges in the US with 186,733 or 31.6 percent being defined as substandard. Developing new methods for inspection and evaluation of bridges has recently received considerable attention. The characterization of aging responses in structural materials entails establishing the fundam…
A series of substituted triarylmethylium cations, including malachite green, tris(4-methoxyphenyl)methylium, and bis(4-methoxyphenyl)phenylmethylium cations, has been prepared adsorbed on tridirectional large pore zeolites Y and β in their H + or La 3+ form, as well as within the novel mesoporous aluminosilicate MCM-4…
The interconversion of model compounds {[(NH 3 ) 3 Cu] 2 (μ-η 2:η 2 -O 2 )} 2+ ( 1 ) and {[(NH 3 ) 3 Cu] 2 (μ-O) 2 } 2+ ( 2 ) has been examined using multireference second-order perturbation theory with an 8-electron/8-orbital active space. At this level of theory, 1 and 2 are separated by only 0.3 kcal/mol, and the b…
Oxygen intercalation into a pyrochlore at room temperature is reported. A simple chemical route was employed. Previously only perovskite or a few closely related phase have demonstrated an ability to act as hosts for such intercalation. The specific system studied was the interstitial solid solution Ce 2 Zr 2 O 7+ x (…
Using dynamic NMR spectroscopy, the kinetic isotope effects of the degenerate single hydron transfer in the conjugate 15 N-labeled porphyrin anion Por-H - dissolved in organic solvents have been measured as a function of temperature. Por-H - was generated by dissolving the labeled parent compound porphyrin together wi…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTHighly Enantioselective Epoxidation of trans-Stilbenes Catalyzed by Chiral KetonesDan Yang, Xue-Chao Wang, Man-Kin Wong, Yiu-Chung Yip, and Man-Wai TangView Author Information Department of Chemistry, The University of Hong Kong Pokfulam Road, Hong Kong Cite this: J. A…
A comprehensive electrochemical (cyclic and square-wave voltammetry, coulometry) and static spectroscopic (absorption, resonance Raman (RR), electron paramagnetic resonance (EPR)) study is reported for a series of dimeric and trimeric porphyrin-based arrays. All the arrays consist of tetraarylporphyrins linked via eth…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTn-Channel Organic Transistor Materials Based on Naphthalene FrameworksJoyce G. Laquindanum, Howard E. Katz, Ananth Dodabalapur, and Andrew J. LovingerView Author Information Bell Laboratories, Lucent Technologies 600 Mountain Ave., Murray Hill, New Jersey 07974 Cite th…