Materials Literature
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Low-energy (0.5−30 eV) electron irradiation of the thymine- and halogen-substituted nonamers Au/Cy* 6 T 3 and Au/Cy* 6 (FU,BrU,IU) 3, chemisorbed onto a gold surface, leads to the desorption of neutral CN and OCN from fragmentation of the DNA base ring. No neutral halogen-containing species are detected. The cross sec…
Dendrimers are well defined, highly branched macromolecules that radiate from a central core and are synthesized through a stepwise, repetitive reaction sequence that guarantees complete shells for each generation, leading to polymers that are monodisperse. The synthetic procedures developed for dendrimer preparation…
Scratch damage modes in zirconia‐based ceramics—Mg‐PSZ, Y‐TZP, and Ce‐TZP—are investigated. Precursor indentation tests with a tungsten carbide sphere foreshadow the nature of damage: in Mg‐PSZ, extensive (quasi‐)plastic deformation in the region outside and beneath the contact; in Y‐TZP, less plastic deformation bene…
We present a detailed electromagnetic analysis for the radiation of an electric source located inside grating structures. Our analysis is based on the differential method and uses the scattering-matrix algorithm. We show that gratings that exhibit periodic modulations along two spatial directions (crossed gratings) en…
A water-soluble porphyrin, meso -tetra(4-sulfonatophenyl)porphyrin (TSPP), has been associated with two different polycations, poly(diallyldimethylammonium chloride) (PDDA) and poly(ethyleneimine) (PEI), to investigate the effects of polymer binding upon the TSPP structure and excited-state dynamics both in solution a…
The translational diffusion coefficients of supercooled heavy water ( 2 H 2 O) at atmospheric pressure were examined using pulsed-gradient spin−echo NMR diffusion measurements down to 244 K. At this temperature the diffusion coefficient was 1.67 × 10 -10 m 2 s -1 . The temperature dependence of the 2 H 2 O diffusion w…
The effect of hot‐pressing temperature on the densification behavior and mechanical properties of titanium diboride (TiB 2 ) was investigated. TiB 2 specimens were hot‐pressed for 1 h at temperatures in the range of 1500°–1800°C, with an addition of 2.5 wt% of silicon nitride (Si 3 N 4 ) as a sintering aid. The densit…
H-bonding was used to alter the molecular packing of a bithiazole oligomer. Comparison of the solid-state UV−vis absorption spectra of the H-bonded oligomer with a related non-H-bonded oligomer allowed for the assignment of the optical signature of π stacking in crystals or ordered aggregates of conjugated oligomers o…
High-luminance electroluminescent devices have been newly developed using a Ga 2 O 3 :Mn thin film prepared by a sol-gel process. The sol-gel process, which eliminates the need for vacuum processes, enabled the inexpensive preparation of Ga 2 O 3 :Mn thin films on large-area thick ceramic sheet insulators. Gallium ace…
Voltage-modulated scanning force microscopy has been applied to investigate domain kinetics in triglycine sulfate single crystals, thermally quenched from the paraelectric to the ferroelectric phase. Temporal analysis of the equal-time correlation functions shows that the average domain size grows initially with a pow…
Abstract A series of amorphous fluoro‐polyetherimides based on 2,2′‐bis(3,4‐dicarboxyphenyl) hexafluropropane dianhydride (6FDA) and di‐ether‐containing diamines 4,4′‐bis(3‐aminophenoxy)diphenyl sulfone ( m ‐SED), 4,4′‐bis(4‐aminophenoxy)diphenyl sulfone ( p ‐SED), 4,4′‐bis(4‐aminophenoxy)diphenyl propane (BPADE) were…
Rust formed on weathering steel and that on mild steel were studied by Mössbauer spectroscopy at various temperatures from room temperature to 12 K. The observed spectra were decomposed into the contribution of fine antiferromagnetic particles of α-FeOOH (85 at.%, T N =403 K) and that of γ-FeOOH (15 at.%, T N =73 K).…
A new modification of MnSb 2 S 4 was synthesized by solid state reaction of MnS, and Sb 2 S 3 at 500 °C. The monoclinic, purple-red compound crystallizes in the HgBi 2 S 4 structure type. Single crystal measurements provided the space group C2/m (no. 12) with a = 12.747(3) Å, b = 3.799(1) Å, c = 15.106(3) Å, β = 113.9…
In this work we have studied the dispersion of the disorder-induced (D) and the second-order (G') Raman bands in single wall carbon nanotubes using several laser excitation energies (E laser) in the range 1.5-3.0 eV. An anomalous step-like behavior was observed in the E laser dependence of the G'-band frequency. This…
Nickel zinc ferrite of composition Ni0·5 Zn0·5 Fe2O4 was prepared by the citrate precursor method at temperatures as low as 100°C. This is much lower than those used in the conventional ceramic method for the preparation of ferrites (~1000°C). The dc resistivity of the sintered specimens was observed to be ~108 Ω cm w…
[reaction: see text] A cerium(IV) double decker porphyrin (1) bearing four 4-methoxyphenyl groups was synthesized. Compound 1 shows a positive, homotoropic allosteric effect in metal recognition of Ag(+) ion, and the peripheral pi clefts of 1 act as effective binding sites for Ag(+) ion.
This work reports Raman detection of the tetragonal $\ensuremath{\rightarrow}$ monoclinic phase transition in ${\mathrm{PbZr}}_{0.52}{\mathrm{Ti}}_{0.48}{\mathrm{O}}_{3}$ ceramics near the morphotropic phase boundary at low temperatures. The transition is characterized by changes in the frequency of lattice modes with…
Inorganic nano- and microtubes intercalated with silver and gold are reported here for the first time. These alloyed phases of MoS2 and WS2 are stabilized by the tubular structure—remaining unknown in the bulk material. Analysis with TEM shows that the Au intercalated tubes (the Figure shows the termination of an Au–W…
The Adam-Gibbs paper [G. Adam and J. H. Gibbs, J. Chem. Phys. 43, 139 (1965)], one of the most cited works in physics, has a continuing influence on research into glass transition. This paper is generally considered as the turning point from rare free volume to small configurational entropy as the reason for slow mole…
The LB technique is an important way to obtain the ordered aggregate of nanometre-sized particles. However, with the usual LB technique only those particles capped by short-chain molecules (<C 12 ) can form a highly ordered two-dimensional (2D) arrangement. When the capping molecules become longer, it is difficult to…