Materials Literature
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A series of trinuclear Cu(II)Ln(III)Cu(II) complexes with the bridging ligand 2,6-di(acetoacetyl)pyridine have been prepared by one-pot reaction with Cu(NO(3))(2).3H(2)O and Ln(NO(3))(3).nH(2)O in methanol. X-ray crystallographic studies for all the complexes indicate that two L(2)(-) ligands selectively sandwich two…
Reactivity, kinetic, and thermodynamic studies are reported for reactions of a rhodium(II) bimetalloradical with H(2), and with the methyl C-H bonds for a series of substrates CH(3)R (R = H, CH(3), OH, C(6)H(5)) using a m-xylyl diether tethered diporphyrin ligand. Bimolecular substrate reactions involving the intramol…
Abstract Polymer melt‐direct intercalation or exfoliation is a promising approach for the preparation of nanocomposites. The structure of nanoclay platelets in the nanocomposites depends not only on the properties of polymer matrix and nanoclay, but also on the operating conditions during processing. The objective of…
Polyelectrolyte multilayers with continuously variable amounts of ionizable weak acid functionality were prepared by blending ionizable and nonionizable polyelectrolytes in the deposition solutions. Diluting ionizable groups in this way yielded multilayers that were more structurally stable, shown by thickness and ato…
Calcium carbonate is an important and ubiquitous component of biological and geochemical systems. In this study, the surface chemistry of calcium carbonate with several trace atmospheric gases including HNO3, SO2, HCOOH, and CH3COOH is investigated with infrared spectroscopy. Adsorbed carbonic acid, H2CO3, is found to…
Here we review major breakthroughs in the rapidly developing research area of nanomaterial synthesis in supercritical fluids focusing on both the fundamental science and processing advantages in the application areas of separations, assembly and scale-up of synthesis. Density-tunable control of the solvation strength,…
We have utilized resonant x-ray diffraction at the Mn L(II,III) edges in order to directly compare magnetic and orbital correlations in Pr0.6Ca0.4MnO3. Comparing the widths of the magnetic and orbital diffraction peaks, we find that the magnetic correlation length exceeds that of the orbital order by nearly a factor o…
The pH-dependent loading and release behavior of small hydrophilic molecular probes in polyallylamine and hyaluronic acid multilayer films was investigated. These studies were carried out using the water-soluble dyes Indoine Blue and Chromotrope 2R, and their loading and release profiles were followed with UV−vis spec…
RATIONALE AND OBJECTIVES: To evaluate the safety and pharmacokinetics of a newly developed MR contrast medium consisting of very small superparamagnetic iron oxide particles (VSOP) coated with citrate (VSOP-C184) in a clinical phase I trial. METHODS: A total of 18 healthy subjects received either VSOP-C184 (core diame…
A two-phase sequential dynamic change in the secondary structure of hen egg lysozyme (Lys) adsorbed on solid substrates was observed. The first phase involved fast conversion of alpha-helix to random/turns (within the first minute or at very low coverage or high substrate wettability) with no perceptible change in bet…
The physical properties of ultrathin NaCl overlayers on the stepped Cu(311) surface have been characterized using scanning tunneling microscopy (STM) and spectroscopy, and density functional calculations. Simulations of STM images and differential conductance spectrum were based on the Tersoff-Hamann approximation for…
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…