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。
Quantum-well (QW) states in {\it nonmagnetic} metal layers contained in magnetic multilayers are known to be important in spin-dependent transport, but the role of QW states in {\it magnetic} layers remains elusive. Here we identify the conditions and mechanisms for resonant tunneling through QW states in magnetic lay…
Surface functionalization of the solid heteropolyacid H3PW12O40 with a bulky PEG-containing quaternary ammonium cation through partial proton exchange leads to a polyoxometalate-based liquid salt with high-temperature proton conductivity ( approximately 10-3 S cm-1 at 140 degrees C) under dry conditions. The proton co…
Nanocrystalline cerium oxide based powders (CeO 2, (GdO 1.5 ) 0.2 (CeO 2 ) 0.8, and (SmO 1.5 ) 0.2 (CeO 2 ) 0.8 ) have been produced using combustion synthesis with glycine as fuel and nitrate as oxidizer. The pure CeO 2 powders prepared by using different glycine-to-nitrate ratios have been characterized by X-ray dif…
Ge(2)Bi(2)Te(5) in the GeTe-Bi(2)Te(3) pseudobinary system has two single-crystalline phases: a metastable phase with an NaCl-type structure and a stable phase with a nine-layer trigonal structure. In the metastable phase, the structure consists, in the hexagonal notation, of infinitely alternating stacks of Te and Ge…
The dielectric properties of $\mathrm{Ca}{\mathrm{Cu}}_{3}{\mathrm{Ti}}_{4}{\mathrm{O}}_{12}$, a material showing colossal values of the dielectric constant, were investigated over a broad temperature and frequency range extending up to $1.3\phantom{\rule{0.3em}{0ex}}\mathrm{GHz}$. A detailed equivalent-circuit analys…
A universal conduction model is proposed for high-voltage direct-current (HVDC) insulation materials. The model is able to reproduce many well-known experimental facts and is very useful for finite-element electro-thermal simulations required in the design process of HVDC cables and cable-accessories. The proposed mod…
Butyl acrylate resin–iron chelate was prepared by cross-linking with divinyl benzene and complexation with ferric chloride. The prepared resin was incorporated in different amounts into low-density polyethylene samples filled with magnesium hydroxide. Flammability properties were evaluated by cone calorimetry and ther…
Aim of this paper is to validate the effectiveness of an artificial intelligence technique devised for tree diagnosis in solid insulation systems. For this purpose, electrical and optical partial discharge (PD) measurements were carried out on specimens containing treed regions of different typologies ("bush" and "bra…
The common use of zinc oxide varistors has brought about qualitative changes in the overvoltage protection of electronic and electric power equipment. This is due to the special properties of ZnO varistors, mainly the high current-voltage characteristic nonlinearity and the capacity to withstand strong current surges.…
For the operation programs and preventive maintenance a fundamental focus is to monitor the efficiency of components of a distribution system. A right goal for the maintenance is the evaluation of synthetic parameters suitable to furnish, after each measuring time interval, the updated check up of the maintaining comp…
The effect of accelerated aging by immersion in boiling water on the tensile behavior of a hybrid ramie-cotton fabric polyester composite was evaluated. Under these conditions, fast water absorption by the lignocellulosic fibers took place, causing a sharp reduction in the tensile strength of the composite during the…
Two kinds of rubber composites were prepared by melt mixing of acrylonitrile-butadiene rubber (NBR) with zinc dimethacrylate (ZMA). In one system ZMA was added in the form of powder; and, in another system, the ZMA was prepared by in-situ reaction of ZnO and methacrylic acid (MA) during melt mixing. Both systems showe…
Time‐resolved laser‐induced fluorescence spectroscopy (TRLFS) was employed to determine the inner‐sphere (i.e., first coordination sphere) hydration number (N H2O) of lanthanide(III) ions (Ln = Sm, Eu, Tb, and Dy) in the TRPO‐dodecane/HNO3 (or HNO3–NaNO3) system under various conditions. In addition, the N H2O of Ln(I…
Studies of secondary and backscattered electron yield curves of thin-film dielectrics have recently been made using pulsed, low current electron beam methods to minimize insulator charging. These capabilities have allowed us to investigate the evolution of surface and internal charge profiles as a function of low ener…
Today, high voltage power semiconductors such as IGBTs, are being developed. As the voltage is increased, local electric fields applied to dielectric materials also increase. Local deterioration of dielectric materials due to partial discharges (PD) may appear and affect the reliability of the whole component. The usu…
Recently, potassium iodide was inserted into single-walled carbon nanotubes. We present here a first-principles density-functional theory calculation of the electronic and optical properties of a potassium iodide intercalated (10,10) nanotube. Band structure, density of states, and charge distribution of the intercala…
Abstract Poly(ethylene‐ co ‐octene) (PEO) is a new thermoplastic elastomer that has the wide variation in mechanical, thermal, optical, and elastomeric properties. The variety of PEO properties results from incorporation octene comonomer in polyethylene backbone. Because of the wide difference in the copolymer propert…
This investigation regards the partial discharges (PD) ageing processes of motor winding insulation (enamelled wires) subjected to "fast rising and dropping" voltages, i.e. to a PWM controlled inverter drive voltage waveform. Twisted pair specimens were fed till failure by two different PWM like (and by a sinusoidal)…
We have fabricated light emitting porous silicon micropatterns with controlled emission intensity. This has been achieved by direct write irradiation in heavily doped p-type silicon (0.02Ωcm) using a 2MeV proton beam, focused to a spot size of 200nm. After electrochemical etching in hydrofluoric acid, enhanced photolu…
The field emission properties of films of aligned multiwalled nanotubes produced by plasma-enhanced chemical vapor deposition are studied as a function of their length. The measured turn-on and threshold electric fields decrease strongly with increasing nanotube length, reaching values of below 1 V∕μm for the longest…