Materials Literature
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The photoconductivity of nanorods self-assembled from meso-tetrakis(4-sulfonatophenyl)porphine is described. The nanorods are insulating in the dark. Upon illumination with 488 nm light, the nanorods become photoconductive, exhibiting a rapid turn on/off (<100 ms) of the current when the light is turned on/off. This p…
Results of molecular-mechanics simulations of axial and torsional deformations of a single wall carbon nanotube are used to find Young's modulus, the shear modulus, and the wall thickness of an equivalent continuum tube made of a linear elastic isotropic material. These values are used to compare the response of the c…
Abstract The full characterization of chitin obtained from squid, shrimp, prawn, lobsters, and king crab is reported. Elemental analysis, including metals such as Ca, Mg, Zn, Cd, Hg, Cr, Mn, Cu, and Pb, was performed, which is quite relevant because the skeleton composition is slightly different for each species. The…
We consider the temperature dependence of the sound attenuation and sound velocity in layered impure metals due to s-wave superconducting fluctuations of the order parameter above the critical temperature. We obtain the dependence on material properties of these fluctuation corrections in the hydrodynamic limit, where…
There are many applications driving the need for frequency agile solid state laser systems for use in the mid-infrared. Most of these are centred on the development of optical parametric oscillators (OPOs), which exploit the non-linear optical characteristics of non-centrosymmetric materials. In a new approach highlig…
Mechanisms of the reactions of representative dipeptides (Gly2, Gly-Ala), oligopeptides (Gly3, Gly4) and the polypeptide (poly-Gly)n) in solution and clay suspensions at 85 degrees C were investigated. The reaction products and their yields were analysed and determined by means of HPLC. Interestingly, hydrolysis, wher…
The increasing knowledge of the energy level structure of the lanthanides has led to new applications for these ions. The Gd3+/Eu3+ quantum cutting couple was discovered a few years ago and may be applied in phosphors for fluorescent tubes based on a VUV xenon discharge. The VUV absorption of the phosphor LiGdF4:Eu3+…
Three disubstituted N-confused porphyrins (2-4) were prepared in ca. 4% yield using a one-pot synthesis. These porphyrins bear 3,5-di-tert-butylphenyl groups substituted at the C(5) and C(20) meso positions and para-substituted (Br, NO(2), ethynyl) phenyl groups at the C(10) and C(15) meso positions. The specific orie…
For the control of three-way catalytic converters (TWCs), simplified models of not only the TWC but also the λ-sensors upstream and downstream of the TWC are required. The accurate interpretation of the sensor signals makes the correction or online identification of model parameters possible. Thus, a precise estimate…
A new isotactic, perfectly alternating polymer of ( S )-lactic acid and oxetane was synthesized by the entropically driven ring-opening polymerization of a 14-membered cyclic diester ( S,S - 3 ) mediated by a zinc alkoxide catalyst. The polymer ( S,S -PMOD) was characterized by NMR spectroscopy, size exclusion chromat…
[structure: see text] [structure: see text] [structure: see text] Several Precipiton phosphines were prepared and employed in the Staudinger reaction and in the reduction of secondary ozonides. Both amines and aldehdyes were obtained in good to excellent yields and purities. After use of the phosphine, isomerization a…
Hyperfine structure is observed on several infrared transitions to the 5I7 and 5I6 multiplets of the Ho3+ C4v centre in CaF2. Particularly complex and detailed hyperfine structures are observed for transitions to the Y3 level of the 5I7 multiplet, which include the appearance of ΔIz ≠ 0 transitions. The hyperfine line…
For pyrite, ${\mathrm{FeS}}_{2},$ both the imaginary and real parts of the anisotropy of the iron atomic scattering factor are experimentally determined as functions of the x-ray energy near the iron K-edge and compared with ab initio calculations. The anisotropy appears due to the deformations of the electronic state…
Abstract A study of the relaxations and the conductivity of poly(ether imide) (PEI) ULTEM 5000 was carried out. The results were compared with the ones obtained in a previous study of PEI ULTEM 1000. The glass transition temperature was determined by differential scanning calorimetry (DSC). Then, the relaxations of PE…
Static and time-resolved magneto-optical spectra of the ferromagnetic semiconductor (Ga,Mn)As show that a pulsed photoexcitation with a fluence of 10 microJ/cm(2) is equivalent to the application of an external magnetic field of about 1 mT, which relaxes with a decay time of 30 ps. This relaxation is attributed to the…
A facile method with interface assembly was developed to prepare TiO 2 /CdS composite hollow microspheres. By changing reactant concentration, stirring rate, and temperature, the hollow microspheres could be controlled in diameter, shell thickness, and composition. The morphology, structure, composition, and photolumi…
Abstract Copolymers of 2‐( o ‐chlorophenyl)‐4‐methylene‐1,3‐dioxolane with methyl methacrylate and styrene were synthesized in benzene at 85 °C in the presence of 2,2′‐azobisisobutyronitrile as initiator. The structure of the resulting copolymers was investigated and a polymerization mechanism was proposed. The intrin…
The liquid-crystal molecular order near the rubbed polymer surface is reexamined by the improved torque balance method. The surface azimuthal anchoring strength measured by the improved torque balance method is several times larger than that believed conventionally, considered to be significantly affected by the phase…
Abstract Bing cherries were coated with sodium caseinate‐ or milk protein concentrate‐based edible coatings. Besides the proteins (100 g kg −1 ), the coating formulations also included glycerol (about 300 g kg −1 protein) and either beeswax or a stearic–palmitic acid blend at a concentration of 0, 100 or 300 g lipid p…
A new synthesis of Bi(0) nanoparticles is reported. A low temperature solution phase reduction of BiCl 3 with t -BuONa activated sodium hydride at 65 °C has been successfully used to prepare large quantities of colloidal Bi(0) nanoparticles with a diameter in the range 1.8–3.0 nm. The resulting Bi nanoparticles were c…