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。
We present a versatile and highly configurable scanning acoustic platform. This platform, comprising of a high frequency transducer, bespoke positioning system and temperature-regulated sample unit, enables the acoustic probing of materials over a wide range of length scales and with minimal thermal aberration. In its…
The magnetism of C-doped SnO2 (001) surfaces is studied using first-principles calculations. It is found that carbon does not induce magnetism in bulk SnO2 when located at the oxygen site but shows a large magnetic moment at the SnO2 (001) surface. The magnetic moment is mainly contributed by the carbon atoms due to e…
We present a detailed analysis of the results of our numerical study of the crystal and electronic structure of the room temperature organometallic ferrimagnet of general composition V(TCNE)$_{x}$ with $% x\approx 2$. The results of the LSDA+$U$ study show that the experimentally determined structure complies with the…
Negative refraction is such a prominent electromagnetic phenomenon that most researchers believe it can only occur in artificially engineered metamaterials. In this article, we report negative refraction for all incident angles for the first time in a naturally existing material. Using ellipsometry measurement of the…
With a motivation to understand microscopic aspects of ScN, ZrN, and HfN relevant to the thermoelectric properties of nitride metal/semiconductor superlattices, we determine their electronic structure, vibrational spectra and thermal properties using first-principles calculations based on density functional theory wit…
In this paper, we report the synthesis of hexagonally ordered aluminum-containing mesoporous silica, Al-MCM-41, from natural attapulgite (Al-substituted Si(8)O(20)Mg(5)(OH)(2)(H(2)O)(4) x 4 H(2)O) without addition of silica or aluminum reagents. A pretreatment process involving sequential mechanical grinding and acid…
Because of the unique combination of their attractive properties, porous ceramics are considered as candidate materials for several engineering applications. The production of porous ceramics from polysiloxane precursors offers advantages in terms of simple processing methodology, low processing cost, and easy control…
Several finely dispersed low-temperature dioctahedral micas and micaceous minerals that form solid solutions from (Mg,Fe)-free illite to aluminoceladonite via Mg-rich illite, and from Fe 3+ -rich glauconite to celadonite have been studied by X-ray diffraction and chemical analysis. The samples have 1M and 1Md structur…
The dielectric response of hard (Fe-doped) and soft (Nb-doped) rhombohedral Pb(Zr0.58Ti0.42)1−xMexO3 (Me=Fe or Nb) ceramics was studied at subswitching conditions over a wide range of temperatures (50–450 °C) and frequencies (10 mHz to 10 kHz). The results show qualitative differences in the behavior of the acceptor-…
Partial discharge (PD) measurements are an important tool for assessing the health of power equipment. Different sources of PD have different effects on the insulation performance of power apparatus. Therefore, discrimination between PD sources is of great interest to both system utilities and equipment manufacturers.…
Thermal conductivity is one of the key parameters in the figure of merit of thermoelectric materials. Over the past decade, most progress in thermoelectric materials has been made by reducing their thermal conductivity while preserving their electrical properties. The phonon scattering mechanisms involved in these str…
Nanoseparation and concomitant purification of nanoparticles by ultracentrifugation in a nonhydroxylic organic density gradient has been demonstrated by separating several typical colloidal nanoparticles, including Au, Ag, and CdSe. Successful separation of Au nanowires from their spherical counterparts showed that co…
Ultraviolet (UV) photodetectors based on ternary Zn2GeO4 nanowire (NW) networks are demonstrated. The devices show fast response and recovery time, which is attributed to the unique NW-NW junction barrier dominated conductance for network devices. The UV-light induced barrier height modulation is much faster than the…
A series of chiral NNO-tridentate Schiff base ligands derived from natural amino acids were reacted with zinc(bis-trimethylsilylamide)(2) to provide metal complexes which have been fully characterized. One of these derivatives was further reacted with p-fluorophenol to yield a phenoxide complex. X-ray crystallographic…
Gold-nickel nanoparticles (NPs) of 3-4 nm diameter embedded in silica nanospheres of around 15 nm have been prepared by using [Au(en)(2)Cl(3)] and [Ni(NH(3))(6)Cl(2)] as precursors in a NP-5/cyclohexane reversed-micelle system, and by in situ reduction in an aqueous solution of NaBH(4)/NH(3)BH(3). Compared with monome…
Various types of nanoparticles, such as liposomes, polymeric micelles, dendrimers, superparamagnetic iron oxide crystals, and colloidal gold, have been employed in targeted therapies for cancer. Both passive and active targeting strategies can be utilized for nano-drug delivery. Passive targeting is based on the enhan…
A facile way to synthesize nanometer-sized polymer (polypyrrole, PPy) particles is explored on the basis of the formation of complexes between water-soluble polymers and metal cations in aqueous solution. The metal cation is used as an oxidizing agent to initiate the chemical oxidation polymerization of the correspond…
Changes in the dielectric breakdown field of polyimide (PI) films have been studied from 25 to 400°C under dc ramps. Both the area (from 0.0707 to 19.635 mm2) and thickness (from 1.4 to 6.7 ¿m) dependences of the dielectric breakdown field have been carried out using the Weibull distribution function. The 63%-breakdow…
The recently introduced transformation-electromagnetics techniques provide a new methodology for designing devices that possess novel wave-material interaction properties. They are based on the form invariance of Maxwell's equations under coordinate transformations. These methods provide an extremely versatile set of…
Information on environmental concentrations is needed to assess the risks that engineered nanomaterials (ENM) may pose to the environment. In this study, predicted environmental concentrations (PEC) were modeled for nano-TiO2, carbon nanotubes (CNT) and nano-Ag for Switzerland. Based on a life-cycle perspective, the m…