Materials Literature
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One of the biggest challenges in cell biology is the imaging of living cells. For this purpose, the most commonly used visualization tool is fluorescent markers. However, conventional labels, such as organic fluorescent dyes or green fluorescent proteins (GFP), lack the photostability to allow the tracking of cellular…
We present a review of the Raman spectra of graphite from an experimental and theoretical point of view. The disorder-induced Raman bands in this material have been a puzzling Raman problem for almost 30 years. Double-resonant Raman scattering explains their origin as well as the excitation-energy dependence, the over…
In this study, the erosion of poly(tetrafluoroethylene) TFE Teflon by hyperthermal atomic oxygen (AO) has been examined using X-ray photoelectron spectroscopy (XPS). The initial F/C atom ratio of 1.66 decreases to 1.15 after a 2 h exposure to a flux of 2 × 10 15 atoms/cm 2 s AO with an average kinetic energy ∼5 eV. Th…
The reaction of the cyclotetraphosphate ion (P(4)O(12)(4)(-)) with [CpTiCl(3)] (Cp = eta(5)-C(5)Me(5)) gives [(CpTi)(2)(P(4)O(12))(2)](2)(-) where the P(4)O(12) ligands adopt a saddle conformation, while that with [(CpTiCl)(3)(mu-O)(3)] leads to [(CpTi)(3)(mu-O)(3)(P(4)O(12))](-) containing a crown form P(4)O(12) liga…
The diffusion of all stable lanthanides was measured both in calcia stabilized zirconia (CSZ) and in yttria stabilized zirconia (YSZ) in the temperature range between 1,286 and 1,600 degrees C. The lanthanide diffusion coefficients obtained increase with increasing ionic radius. The experimental activation enthalpy of…
Rodlike fibrous structures are increasingly found with biomacromolecules, e.g. silks, elastin, and collagen. Here we propose a multiblock copolymer model that can lead to these larger-scale structures. One component consists of highly regular blocks, whereas the blocks of another, incompatible component exhibit a wide…
Applied electric fields are known to induce significant changes in the properties of systems of polarizable molecules or particles. For rod-shaped molecules, the field-induced behavior can be rather surprising, as in the case of the negative electric birefringence of concentrated solutions of rodlike polyelectrolytes.…
Strong optically stimulated luminescence (OSL), stimulated by blue light, has been observed, for the first time, in natural calcium fluoride (CaF(2)) phosphor, used as thermoluminescence dosemeters. Traps responsible for all three thermoluminescence (TL) peaks appearing upto 300 degrees C, i.e. 126, 196 and 264 degree…
Abstract Hybrid nanocomposite films of poly(vinylsilsesquioxane) (PVSSQ) and polyimide (PI) (PI/PVSSQ) were prepared via sol‐gel process from triethoxyvinylsilane (VSSQ) and thermal imidization from 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA)‐ p ‐phenylene diamine (PDA) polyamic acid (BPDA‐PDA PAA). We invest…
Modelling and analysis of the high-voltage flyback transformer utilised in small-sized high-voltage power supplies are presented. The equivalent circuit model, frequency characteristics and transient behaviour are investigated to analyse the effects of parasitic parameters in the discontinuous conduction mode. Simulat…
We have synthesized a coil-rod-coil molecule based on a reactive rod block that self-organizes into a 3-D hexagonal close-packed (hcp) bundle structure in the melt state. Photo-cross-linking within an aromatic bundle yielded macromolecular disklike objects (molecular weight of 330 kDa) with a narrow size distribution…
We present a review of our initial studies concerning the control of polymorphism in semicrystalline polymers with cyclodextrins (CDs). CDs are cyclic starch oligomers with six (α-CD), seven (β-CD), and eight (γ-CD) α-1,4-linked glucose units possessing bracelet structures with hydrophobic and hydrophilic interiors an…
We report a reversible liquid-solid transition upon heating of a simple solution composed of a-cyclodextrine (alpha CD), water, and 4-methylpyridine. These solutions are homogeneous and transparent at ambient temperature and solidify when heated to temperatures between 45 degrees and 75 degrees. Quasielastic and elast…
As trivalent ${\mathrm{Nd}}^{3+}$ and divalent ${\mathrm{Ca}}^{2+}$ ions have virtually the same ionic size, ${\mathrm{Nd}}_{x}{\mathrm{Ca}}_{2\ensuremath{-}x}{\mathrm{FeMoO}}_{6}$ is a quasi-ideal material to explore electron-doping effects in double perovskites. We report here a study of its structural, magnetic, an…
Porous thin films have been fabricated by physical vapor deposition at an extremely oblique angle of incidence (85°). This deposition technique, called glancing angle deposition (GLAD), was used to create thin films composed of isolated helical columns. By investigating a variety of dielectrics, we found that helical…
Can magnetic interactions between single-molecule magnets (SMMs) in a crystal establish long-range magnetic order at low temperatures deep in the quantum regime, where the only electron spin fluctuations are due to incoherent magnetic quantum tunneling (MQT)? Put inversely: can MQT provide the temperature dependent fl…
Recently, a novel, neural-networks-based method, the DFT-NEURON method, was developed to improve the accuracy of first-principles calculations and was applied to correct the systematic deviations of the calculated heats of formation for small-to-medium-sized organic molecules (Hu, L. H.; Wang, X. J.; Wong, L. H.; Chen…
Far infrared spectra of 14 commonly used explosive samples have been measured by using Fourier Transform Infrared Spectroscopy (FTIR) and THz Time-Domain Spectroscopy (THz TDS). New absorption resonances between 20 cm<sup>-1</sup> and 650 cm<sup>-1</sup> are reported. Below 20 cm<sup>-1</sup>, no clear absorption reso…
The preparation and properties of [Mn(4)O(3)(O(2)CPh-R)(4)(dbm)(3)] (R = H, p-Me, p-OMe, and o-Cl; dbm(-) is the anion of dibenzoylmethane) single-molecule magnets (SMMs) with virtual C(S) symmetry are reported. They were prepared by controlled potential electrolysis in 26-80% yields. The structures comprise a distort…
We studied the mechanism of CO oxidation on O-covered Pt(111) surfaces during CO exposure by means of time-resolved near edge x-ray absorption fine structure spectroscopy. Two distinct reaction processes were found to occur sequentially; isolated O atoms and island-periphery O atoms contribute to each process. Combina…