Materials Literature
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Steady state and time-resolved photoluminescence measurements of a homologous series of CdSe cluster molecules were performed over a broad temperature range (T = 5–200 K). The absorption and low temperature PLE onset of the clusters shifts systematically to the blue in smaller clusters, manifesting the quantum confine…
The synthesis and evaluation of the liquid crystalline properties of non-conventional liquid crystals, consisting of two non-identical mesogenic segments interconnected via a paraffinic chain spacer, are of considerable current interest. In particular, chiral dimesogens possessing a cholesteryl ester unit as the chira…
We present results of the feasibility study on photoaddressable polymers (PAPs) applied to optical disc systems. PAPs represent a new class of organic rewritable materials that exhibit a huge signal birefringence ( Δ n ) at the readout wavelength. By optimizing the disc structure and the readout optics, the signal amp…
The non-resonant nonlinear optical properties of CdS nanocrystals (NCs) embedded in silica (i) and forming matrix-free (MF) almost close-packed films (ii) were studied using the Z-scan technique. Among the group (i), samples containing NCs covered with a HgS and CuS shell were investigated. The highest value of the no…
Sol–gel films containing manganese-doped CdS nanocrystals are synthesized. Photoluminescence spectra and kinetics of the Mn2+ ion emission at room temperature have been studied. It is found that the quantum confinement effect does not modify the emission lifetime as compared to bulk material.
One of the agro-environmental characteristics of Brittany is the extensive use of pesticides, which leads to high concentrations of atrazine in continental water systems. Periphytic algae play a basic part in aquatic ecosystems and some of them, diatoms, are highly sensitive to environmental changes. Analyses of diato…
Twenty hours of mechanical activation of mixed oxides at room temperature led to the formation of Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) in excess PbO. The crystallinity of the activation‐derived perovskite PMN phase was further established when the activated PMN–PbO phase mixture was subjected to calcination at 800°C. Pyrochlor…
We report on mass spectroscopic measurements of species originating from a microwave (MW) discharge plasma under simulated diamond deposition conditions. The plasma is produced in a 30 W MW flow tube through which flows a gas mixture of about 1% methane admixed in hydrogen. Plasma composition was investigated as a fun…
ABSTRACT: A considerable amount of squid mantle collagen, 45% to 70% of total collagen, was not solubilized even after 30 min of heating in boiling water with its fibrous structure left intact. Pyridinoline, one of the major intermo‐lecular crosslinks in matured collagen, was more predominantly included in the insolub…
Abstract When antisolvents are applied to crystallize sodium carbonate from aqueous solutions, the transition temperature at which the hydrates are in equilibrium is decreased. Two models proposed can predict the influence of the amount and type of antisolvent on the transition temperature. Only binary data of the wat…
Ring-opening polymerization of macrolides in the presence of aliphatic polyesters has been performed using Pseudomonas lipase as catalyst to produce ester copolymers with molecular weights of several thousands. The polymerization behavior was monitored by SEC and NMR. 13C NMR analysis showed that the resulting polymer…
The influence of the Mn2+ concentration, the nature of the passivating polymer and UV irradiation on the luminescence efficiency of nanocrystalline ZnS:Mn2+ is investigated. With increasing Mn2+ concentration the quantum efficiency increases, until it reaches a stable value. No drastic decrease in quantum efficiency i…
Samples prepared from three different amalgam brands were coupled to two gold alloys and orthodontic brackets. In the resulting galvanic cells, the amalgam coupled to gold were anodic, exhibiting galvanic current densities about one order of magnitude higher than the uncoupled corrosion current densities of 0.2-0.5 mi…
Six kaolinite [Al 2 Si 2 O 5 (OH) 4 ] samples were synthesized under different conditions of temperature, pressure, and pH from two different starting materials. Chemical composition and properties of the samples were characterized using classical methods (electron microprobe, atomic absorption spectrometry, X-ray dif…
After considerably long time of transesterification reactions between poly(ethylene terephthalate) (PET) and bisphenol-A polycarbonate (PC) in the molten state, random copolymers, referred to be TCET's, can be obtained, which have fairly good compatibilizing effect on the immiscible PC/PET blend. The compatibilizing e…
To define the transcriptional mechanisms contributing to stage- and tissue-specific expression of muscle genes, we performed transgenic analysis of Drosophila paramyosin gene regulation. This gene has two promoters, one for paramyosin and one for miniparamyosin, which are active in partially overlapping domains. Regio…
The temperature and field dependence of alternating-current (ac) susceptibility in a Ni 50 Mn 25 Ga 25 single crystal was measured using an ac susceptometer with a dc magnetic field oriented in the [100] and [110] directions, respectively. It is found that even at very low fields the premartensitic transition temperat…
The luminescence enhancement of Tb 3+ ion bound to amphiphilic linear−dendritic block copolymers [poly(acrylic acid)−dendritic polyether, PAA−Dendr.PE] was investigated. Tb 3+ ion complexes with a PAA chain of block copolymer to form a supramolecular luminophore. The observed prominent enhancement in luminescence prop…
Free-exciton recombination emission of 235 nm in wavelength is obtained by current injection at room temperature from a diamond-based pn junction diode composed of B-doped crystal grown by high-temperature, high-pressure synthesis and a S-doped homoepitaxial layer grown by the chemical vapor deposition method. The dio…
Absorption of far-infrared (FIR) radiation in very small CdSe crystallites (quantum dots, QDs) via excitation of confined dipolar vibrational modes was studied, both theoretically and experimentally. Spatial quantisation of optical phonons was analysed in the framework of a continuum model, which couples the phonon am…