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 have developed a two-phase approach for the synthesis of shape-controlled colloidal zirconia nanocrystals, including spherical-, teardrop-, rod-, and rice grain-shaped particles. We found that the key factors for controlling the shape were the reaction time, the nature of the capping agent, and the monomer concentr…
In these experiments, double-stranded, linear DNA sequences were adsorbed into the pores of spherically shaped acid-prepared mesoporous silica (APMS). The lengths of the sequences were either 760 base pairs or 2000 base pairs. DNA adsorption into the interior of the mesoporous material was confirmed using confocal mic…
The valley splitting of the first few Landau levels is calculated as a function of the magnetic field for electrons confined in a strained silicon quantum well grown on a tilted SiGe substrate, using a parameterized tight-binding method. For a zero substrate tilt angle, the valley splitting slightly decreases with inc…
Gold-tipped CdSe rods (nanodumbbells) were solubilized in an aqueous phase and self-assembled in a head-to-tail manner using biotin disulfide and avidin. The disulfide end of the biotin molecule attaches to the gold tip of the nanodumbbell, and the biotin end of the molecule is able to conjugate to an avidin protein.…
Gibbs free-energy calculations based on density functional theory have been used to determine the possible source of failure of boron carbide just above the Hugoniot elastic limit (HEL). A range of B4C polytypes is found to be stable at room pressure. The energetic barrier for shock amorphization of boron carbide is b…
The floating-zone method and high-pressure synthesis have been used to obtain the hexagonal and the perovskite $R\mathrm{Mn}{\mathrm{O}}_{3}$ $(R=\mathrm{Y},\phantom{\rule{0.3em}{0ex}}\mathrm{Ho},\phantom{\rule{0.3em}{0ex}}\mathrm{Er},\phantom{\rule{0.3em}{0ex}}\mathrm{Tm},\mathrm{Yb},\phantom{\rule{0.3em}{0ex}}\mathr…
We discuss the influence of electrical effects on spin transport, and in particular the propagation and relaxation of spin polarized electrons in the presence of inhomogeneous electric fields. We show that the spin relaxation length strongly depends on electric field gradients, and that significant suppression of elec…
We deposited thin layers of CdS and ZnS nanoparticles embedded in a thermoplastic cyclo-olephin copolymer (COC) with elevated optical transparency and highly bio-compatible. The nanoparticles were obtained by thiolate precursors previously dispersed in the polymer upon thermal treatment at temperatures ranging between…
Comments on "Giant Dielectric Response in the One-Dimensional Charge-Ordered Semiconductor (NbSe_{4})_{3}I" (D. Staresinic et al., Phys. Rev. Lett. 96, 046402 (2006)) and "Colossal Magnetocapacitance and Colossal Magnetoresistance in HgCr_{2}S_{4}" (S. Weber et al., Phys. Rev. Lett. 96, 157202 (2006))
We report direct experimental evidence of the effect of quenched random field on magnetic ordering of La_(0.5)Gd_(0.2)Sr_(0.3)MnO_(3) manganites system. We demonstrate magnetic measurements providing serious evidence to support that quenched random field of Gd divides the system in finite size clusters which undergo c…
The dynamical process where an edge dislocation in fcc copper bypasses an impenetrable precipitate is investigated by means of molecular dynamics simulation. A mechanism that is quite different from the Orowan mechanism is observed, where a dislocation leaves two prismatic loops near a precipitate, i.e., the Hirsch me…
We present a formulation of a nonequilibrium Green's function method for thermal current in nanojunction atomic systems with nonlinear interactions. This first-principles approach is applied to the calculation of the thermal conductance in a one-dimensional chain and carbon nanotube junctions. It is shown that nonline…
Novel NIR fluorescent, conformational restricted aza-dipyrromethene boron difluoride (aza-BODIPY) dyes were prepared by an efficient process. Such conformational restricted aza-BODIPY dyes possess intense absorption, strong fluorescence, high chemical and photostability. Additionally, the sharp fluorescence of non-ami…
The hypothesis that high-Curie-temperature ferromagnetism in cobalt-doped ZnO (${\mathrm{Co}}^{2+}\mathrm{\text{:}}\text{ }\text{ }\mathrm{ZnO}$) is mediated by charge carriers was tested by controlled introduction and removal of the shallow donor interstitial zinc. Using oriented epitaxial ${\mathrm{Co}}^{2+}\mathrm{…
Single crystalline and nearly monodisperse In2O3 nanocrystals with both dot and flower shapes were synthesized in a simple reaction system. This system used indium carboxylates as the precursors with or without alcohol as the activating reagents in a hydrocarbon solvent under elevated temperatures. Limited ligand prot…
In this paper, a hydrothermal synthetic route has been developed to prepare a class of rare-earth fluoride nanocrystals, which have shown gradual changes in growth modes with decreasing ionic radii and may serve as a model system for studying the underlying principle in the controlled growth of rare-earth nanocrystals…
A real turn-on: Two nonplanar three-coordinate boron compounds were synthesized as fluorescent sensors for fluoride that utilize charge-transfer emission. The fluorescence of one of the sensors turns on (see picture) and the other turns off in the presence of fluoride.
A facile wet chemical synthesis method was used to prepare a range of single-crystal Na(Y1.5 Na0.5)F6 nanorods with controllable aspect ratios. Their novel multicolor upconversion (UC) fluorescence has been successfully realized by doping Yb3+/Er3+ (green) and Yb3+/Tm3+ (blue) ion pairs. When doped with Eu3+ and Tb3+…
A new method to stabilize and functionalize surfaces for surface-enhanced Raman spectroscopy (SERS) is demonstrated. Atomic layer deposition (ALD) is used to deposit a sub-1-nm alumina layer on silver film-over-nanosphere (AgFON) substrates. The resulting overlayer maintains and stabilizes the SERS activity of the und…
The nature of the charge carriers in 2D few-layer graphites (FLGs) has been recently questioned by transport measurements [K. S. Novoselov, Science 306, 666 (2004)10.1126/science.1102896] and a strong ambipolar electric field effect has been revealed. Our density functional calculations demonstrate that the electronic…