Materials Literature
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The Macromolecular Structure Database (MSD) group (http://www.ebi.ac.uk/msd/) continues to enhance the quality and consistency of macromolecular structure data in the Protein Data Bank (PDB) and to work towards the integration of various bioinformatics data resources. We have implemented a simple form-based interface…
Recent theoretical work suggested the possibility of constructing a super-resolution diffraction-free lens by using a negative refractive index medium (NRIM). The key proposition is that evanescent waves can be greatly enhanced by increasing the thickness of the NRIM. We report here experimental evidence that confirms…
The charge doped into a semiconductor in a field effect transistor (FET) is generally confined to the interface of the semiconductor. A planar step at the interface causes a potential drop due to the strong electric field of the FET, which in turn is screened by the doped carriers. We analyze the dipolar electronic st…
We report on the photodetecting properties of a ZnO-based thin-film transistor (TFT) that has been fabricated on a SiO2/p-Si substrate by rf magnetron sputtering at room temperature. Our ZnO-based TFT exhibited a saturation current level of about 6.5 μA under a gate bias of 40 V, decent electron mobility of 0.1 cm2/V…
We report a Raman scattering study of polycrystalline CaCu$_3$Ti$_4$O$_{12}$ (CCTO) under pressure up to 5.32 GPa. The pressure dependence of several Raman modes was investigated. No anomalies have been observed on the phonon spectra thereby indicating that the T$_{h}$ (Im$\bar 3$) structure remains stable for pressur…
The electronic band structure of yttrium sesquicarbide Y2C3(Pu2C3 structural type) reported by Akimitsu et al. (2003) as a novel 18-K superconductor is investigated using the first-principle full-potential LMTO method and compared with those of yttrium mono- and dicarbide: cubic YC and 4-K superconductor YC2 (CaC2 str…
A high valent MnVO porphyrin dimer is prepared by peracid oxidation of an MnIII dimer under basic conditions at room temperature (see scheme; mCPBA=m-chloroperbenzoic acid). The addition of an acid to a solution of the MnVO complex results in quantitative dioxygen evolution. Water and/or hydroxide ions are the sourc…
Monolayer gold islands with a thickness of one or a few monolayers on an FeO(111) substrate are found to exhibit identical CO adsorption behavior as large gold particles (see picture). This result suggests that particle thickness does not play a significant role in CO adsorption, and therefore size effects seen for th…
BRENDA (BRaunschweig ENzyme DAtabase) represents a comprehensive collection of enzyme and metabolic information, based on primary literature. The database contains data from at least 83,000 different enzymes from 9800 different organisms, classified in approximately 4200 EC numbers. BRENDA includes biochemical and mol…
All materials undergo some degree of compaction or expansion when exposed to radiation. Multi-component materials are more susceptible to this effect than single-component materials (e.g., fused silica). Nonetheless, the much lower expansion characteristics of multi-component materials -- such as the ultra-low expansi…
Abstract The ultrasonic degradation of poly(vinyl acetate) (PVAc) solutions was carried out in dioxan at 25, 30, 35, 40, and 45 °C to investigate the effects of the temperature and solution concentration on the rate of degradation. The kinetics of degradation were studied by viscometry. The calculated rate constants i…
ADVERTISEMENT RETURN TO ISSUEPREVNoteThrough-Mask Anodic Patterning of Copper Surfaces and Film Stability in Biological MediaHaixia Dai, Corrine K. Thai, Mehmet Sarikaya, François Baneyx, and Daniel T. SchwartzView Author Information Departments of Chemical Engineering and Materials Science and Engineering, University…
Subunits of the enzymes in the crotonase superfamily form tight trimeric disks. In most members of this protein superfamily these disks assemble further into hexamers. Here we report on the 2.1 A structure of a tight hexameric crystal form of the yeast peroxisomal delta(3)-delta(2)-enoyl-CoA isomerase (Eci1p). A compa…
Electroluminescent (EL) BaAl2S4:Eu devices were prepared with a multilayered phosphor, composed of 10–20 alternating BaS:Eu and Al2S3 thin films and a total phosphor thickness of 300 nm. Depending on evaporation and annealing conditions, pure blue EL was obtained (CIE 1931 color coordinates x=0.120, y=0.098). The use…
Abstract We present results for the effects of a crosslinking agent, cure temperature, and UV flux on the electro‐optical properties of polymer‐dispersed liquid crystal (PDLC) cells. These cells were fabricated using a mixture of a liquid crystal (E8) and an acrylic monomer (CN135). The maximum in the first derivative…
Erbium-doped LaF3 transparent gels have been synthesized by the solution synthesis of metal inorganic precursors. The solid solubility of Er3+ can reach 60 mol %, which is almost double the solubility limit of Er3+ in LaF3 synthesized by the Bridgman technique. A quantitative analysis of the absorption and emission sp…
We have measured the energy and entropy differences between $\ensuremath{\beta}$ and martensitic phases in Cu-Zn and Cu-Zn-Al shape-memory alloy systems which display martensitic transitions in a range of temperatures between 30 K and 130 K. We show that the entropy difference originates in the low-energy ${\mathrm{TA…
Many ferroelectric materials like LiTaO3 and LiNbO3 exhibit peculiar behavior in terms of showing a large discrepancy between experimental and theoretical values of coercive field by the use of Landau–Ginzburg model. If a perturbation is given at zero field, then there is also perturbation or fluctuation in polarizati…
We report the kinetics of Mg reduction of SiO2 at the Cu–Mg/SiO2 interface during vacuum annealing. Annealing supersaturated Cu–Mg films to T>∼400 °C results in the interfacial segregation of Mg and the formation of cubic MgO on the silica side of the interface. At ∼475 °C, the film sheet resistance (RS) increa…
A novel method of preparing multiphase ceramic materials from mixtures of preceramic polymers is described. This method employs the typical immiscibility of polymer blends to prepare two-phase SiC−BN ceramic composites by co-pyrolysis of a mixture of two polymeric precursors, allylhydridopolycarbosilane (AHPCS) (nomin…