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。
The term "housane" refers to molecules possessing a bicyclo[2.1.0]pentane core. One was designed, synthesized, and used as a precursor of daucene, a member of the carotane class of sesquiterpenes. The total synthesis was completed, thereby marking the first time that housane-derived cation radicals have been used as t…
Metal nanoshells, which consist of nanometer-scale dielectric cores surrounded by thin metallic shells, have been designed and studied for their linear optical responses. The plasmon resonance of metal nanoshells displays geometric tunability controlled by the ratio of shell thickness either to the core radius or to t…
Colored carbocations beyond the visible! A porphyrin dimer carbocation is synthesized with effective delocalization over 18 conjugated bonds. Placing a carbocation at the center of a conjugated porphyrin dimer shifts its absorption into the infrared and results in strong ultrafast nonlinear optical behavior.
The exploitation of a purely electronic phase change such as the Mott transition could lead to the ultimate electronic device. C. Vaju et al. demonstrates electric-pulse control of the Mott transition in a sulfide (see figure). In this highlight, this breakthrough is reviewed with a brief tutorial of the Mott transiti…
Abstract Cellulose‐ graft ‐poly(ethylene glycol) copolymers were synthesized, and the thermal properties of the copolymers were investigated. The cellulose‐ graft ‐poly(ethylene glycol) copolymers showed solid–solid phase‐transition behavior with a high thermal storage density and good thermal stability in the tempera…
Here we present an easy one-step approach to pattern uniform catalyst lines for the growth of dense, aligned parallel arrays of single-walled carbon nanotubes (SWNTs) on quartz wafers by using photolithography or polydimethylsiloxane (PDMS) stamp microcontact printing (µCP). By directly doping an FeCl 3 /methanol solu…
There is a growing need for cellular imaging with fluorescent probes that emit at longer wavelengths to minimize the effects of absorption, autofluorescence, and scattering from biological tissue. In this paper a series of new environmentally sensitive hemicyanine dyes featuring amino(oligo)thiophene donors have been…
In directional solidification, as the solidification velocity increases, the growth direction of cells or dendrites rotates from the direction of the thermal gradient to that of a preferred cristalline orientation. Meanwhile, their morphology varies with important implications for microsegregation. Here, we experiment…
Abstract Seven halogen‐free flame retardant (FR) compounds were evaluated using pyrolysis combustion flow calorimetry (PCFC) and cone calorimetry. Performance of wires coated with the compounds was evaluated using industry standard flame tests. The results suggest that time to peak heat release rate (PHRR) and total h…
The Vickers hardness and electrical conductivity time–temperature–property (TTP) diagrams for 7055 aluminium alloy were evaluated by an interrupted quench technique. The results show that the critical temperature range was approximately from 230 to 420°C, with the nose temperature of ∼355°C. Rapid decrease in hardness…
The preparation and stabilization of nanoparticles are becoming very crucial issues in the field of so-called "nanocatalysis". Recent developments in supramolecular self-assembled porous materials have opened a new way to get nanoparticles hosted in the channels of such materials. In this paper, a new approach towards…
Analytical ultracentrifugation (AUC) was used to characterize the size distribution and surface chemistry of quantum dots (QDs). AUC was found to be highly sensitive to nanocrystal size, resolving nanocrystal sizes that differ by a single lattice plane. Sedimentation velocity data were used to calculate the ligand pac…
A recently developed method of synthesis of pi-extended porphyrins made it possible to prepare a series of tetrabenzoporphyrins (TBP) with different numbers of meso-aryl substituents. The photophysical parameters of free-bases and Pd complexes of meso-unsubstituted TBP's, 5,15-diaryl-TBP's (Ar2TBP's) and 5,10,15,20-te…
This paper describes a systematic study on the intercalation of an unstable chiral drug l -dopa into layered double hydroxides (LDHs) and the enhancement of its chemical and stereochemical stabilities through host−guest interactions, by virtue of combining experimental and theoretical investigations. l -Dopa has been…
We have used the two-step growth technique, quench condensing followed by an anneal, to grow ultra thin films of silver on glass substrates. As has been seen with semiconductor substrates this process produces a metastable homogeneous covering of silver. By measuring the in situ resistance of the film during growth we…
Reduced Bloch mode expansion is presented for fast periodic media band structure calculations. The expansion employs a natural basis composed of a selected reduced set of Bloch eigenfunctions. The reduced basis is selected within the irreducible Brillouin zone at high symmetry points determined by the medium's crystal…
Combined in situ X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) studies have been conducted to follow gold structural changes of low-content (<1%Au) gold-ceria catalysts in water-gas shift (WGS) reaction tests at 100 and 200 °C; and after heating the used catalysts in…
In this article, we provide a detailed description of the synthesis and properties of Pt dendrimer-encapsulated nanoparticles (DENs) prepared using sixth-generation, hydroxyl-terminated, poly(amidoamine) (PAMAM) dendrimers (G6−OH) and three different PtCl 4 2− /G6−OH ratios: 55, 147, and 240. Results obtained from UV−…
The isothermal magnetoresistance [R($θ$)] of [001] and [110] epitaxial films of La$_{2 / 3}$Sr$_{1 / 3}$MnO$_{3}$ measured as a function of the angle $θ$ between current ($\vec{I}$) and magnetic field ($\vec{H}$), both in the plane of the film, is measured at several temperatures between 10 and 300K. The magnetic easy…
We investigate theoretically the rates of nonradiative decay of excited semiconducting nanotubes by a variety of decay mechanisms and compare them with experimental findings. We find that the multiphonon decay (MPD) of free excitons is too slow to be responsible for the experimentally observed lifetimes. However, MPD…