Materials Literature
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Five different ordered mesoporous silica samples displaying various pore sizes and structures (two small-pore MCM-41, two large-pore MCM-41, and one small-pore MCM-48) and one amorphous silica gel have been grafted with either aminopropyl or mercaptopropyl groups. The resulting aminopropyl-grafted silicas (APS) and me…
A new type of one-dimensional (1D) carbon structure, carbon nanowires (CNWs), was discovered in the cathode deposits prepared by hydrogen arc discharge evaporation of carbon rods. Observation of high-resolution transmission electron microscopy (HRTEM) indicates that a CNW consists of a multiwalled carbon nanotube (MWN…
Abstract A vinyl‐functionalized polyphosphate (PIOP) was synthesized by ring‐opening polymerization of 2‐isopropyl‐2‐oxo‐1,3,2‐dioxaphospholane and 2‐(2‐oxo‐1,3,2‐dioxaphosphoroyloxyethyl methacrylate) with triisobutylaluminum as an initiator. The number‐averaged molecular weight of the PIOP was 1.2 × 10 4 . The avera…
The bonding energetics in a variety of alkaline metal, alkoxides and phenoxides, MOR, was investigated based on the corresponding enthalpies of formation in the crystalline state determined by reaction-solution calorimetry. The results obtained at 298.15 K were as follows: Delta(f)H(m)(o)(MOR, cr)/kJ mol(-1) = 382.7+/…
Abstract A series of fluorinated poly(amide imide)s were prepared from 1,4‐bis(2′‐trifluoromethyl‐4′‐trimellitimidophenoxy)benzene and various aromatic diamines [3,3′,5,5′‐tetramethyl‐4,4′‐diaminediphenylmethane, α,α‐bis(4‐amino‐3,5‐dimethyl phenyl)‐3′‐trifluoromethylphenylmethane, 1,4‐bis(4′‐amino‐2′‐trifluoromethylp…
We demonstrate experimentally the technique of fabricating large diffractive optical elements (DOEs) in thick film on a concave lens surface (mirrors) with precise alignment by using the strategy of double exposure. We adopt the method of double exposure to overcome the difficulty of processing thick photoresist on a…
Abstract Thermally unstable polymers such as poly(methyl methacrylate) are degraded considerably during industrial processing. This degradation and its reduction to a minimum have been investigated in both lab and continuous pilot‐scale experiments. A three‐step degradation mechanism, starting at 180 °C, was proved by…
The reactions of neutral or cationic manganese carbonyl species towards the oxo-nitrosyl complex [Na(MeOH)[Mo(5)O(13)(OCH(3))(4)(NO)]](2-) have been investigated in various conditions. This system provides an unique opportunity for probing the basic reactions involved in the preparation of solid oxide-supported hetero…
In order to clarify the mechanism of the photoluminescence (PL) from amorphous silicon quantum dots $(a$-Si QDs), we calculate, in the tight-binding scheme, the emission spectra and the radiative recombination rate $\mathcal{P}$ of the direct band-to-band recombination process. For a-Si QDs smaller than 2.4 nm in diam…
The microstructure and dynamics of a colloidal system interacting via short-ranged interparticle potential is studied by ultra-small-angle x-ray scattering and x-ray photon correlation spectroscopy. A colloidal gas-liquid type transition is induced when the short-ranged attractive interactions attain sufficient magnit…
Abstract Nitrile rubber (NBR), poly(acrylonitrile‐ co ‐butadiene) or NBR packers, are used to seal oil‐well tubing, where they often come into contact with ZnBr 2 brines at high temperatures and pressures. Under these conditions, NBR exhibits accelerated chemical degradation, which results in embrittlement and crackin…
Abstract The aggregation structure and mechanical properties of liquid silicone rubber, polyurethane (PU), and epoxy (EP) blends were studied. The molecular structure was evaluated by FTIR, and the intermolecular interaction of the three‐phase polyblends was measured by dynamic mechanical analysis. The mechanical prop…
Abstract Potassium diphenyl sulfonate (SSK), poly(sulfonyl phenylene phosphonate) (PSPPP), and their mixtures are proved to be effective flame‐retardants for polycarbonates (PCs) by measuring the limited oxygen index values and UL‐94 of blends. The flame‐retardant systems are characterized by thermogravimetric analysi…
[7-(Dimethylamino)coumarin-4-yl]methyl (DMACM) and [7-(diethylamino)coumarin-4-yl]methyl (DEACM) esters of 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP) and 8-bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP) are described as novel caged compounds for 8-bromo-substituted cyclic nucleotides. Synthesis is…
The (1)H and (17)O NMR relaxometric properties of two cationic complexes formed by Gd(III) with a macrocyclic heptadentate triamide ligand, L(1), and its Nmethylated analogue, L(2), have been investigated in aqueous media as a function of pH, temperature and magnetic field strength. The complexes possess two water mol…
Protein crystallization is a major bottleneck in protein X-ray crystallography, the workhorse of most structural proteomics projects. Because the principles that govern protein crystallization are too poorly understood to allow them to be used in a strongly predictive sense, the most common crystallization strategy en…
We provide the proof for the ${}^{5}D$ term origin of an excited triplet observed in the recent electron-spin-resonance (ESR) experiments by Noguchi et al. [Phys. Rev. B 66, 094404 (2002)]. We have succeeded to fully describe experimental ESR results both for the zero-field g factor, of 3.35, and the splitting D of $4…
We have carried out extensive Monte Carlo simulations of the fusion of tense apposed bilayers formed by amphiphilic molecules within the framework of a coarse grained lattice model. The fusion pathway differs from the usual stalk mechanism. Stalks do form between the apposed bilayers, but rather than expand radially t…
The strongly enhanced cooperative influence of medium polarity and organic structural design on the first hyperpolarizability beta of a novel family of highly polarizable azinium-(CH=CH-thienyl)-dicyanomethanido chromophores 1-3 is described. The dyes can be efficiently synthesized by regioselective protonation/alkyla…
We present molecular dynamics simulations of the thermodynamic melting transition of a bcc metal, vanadium using the Finnis-Sinclair potential. We studied the structural, transport and energetic properties of slabs made of 27 atomic layers with a free surface. We investigated premelting phenomena at the low-index surf…