Propagation Properties of Electromagnetic Wave in a Plasma Slab

In this paper, the calculated results about the propagation properties of electromagnetic wave in a plasma slab are described. The relationship of the propagation properties with frequencies of electromagnetic wave, and parameters of plasma (electron temperature, electron density, dimensionless collision frequency and the size of the plasma slab) is analyzed.

Measurement of small vibration amplitudes of a rough surface by an interferometer with a self-pumped phase-conjugate mirror

The application of a Michelson interferometer with a self-pumped phase-conjugate mirror to measure small vibration amplitudes of a rough surface is described. The distorted wave front of the light that is diffusely reflected from the rough surface is restored by phase conjugation to provide an interference signal with a high signal-to-noise ratio. The vibration amplitudes of a stainless-steel sample are measured with a precision of similar to 5 nm. (C) 2000 Optical Society of America OCIS codes: 120.3180, 190.5040, 120.7280.

Decay dynamics of excited CS2 and NH3 investigated by femtosecond laser

By using the home-made femtosecond laser system and the time-of-flight mass spectrometer, the decay dynamics of excited carbon disulfide (CS2) and ammonia (NH3) are investigated in real time by pump-probe multiphoton ionization detection. The estimated lifetime constant of the NH3 (A) over tilde (1)A(2)' state (51+/-4 fs) agreed quite well with the literature report. For the first time, the decay lifetime constants of the NH3 (E) over tilde'(1)A(1)' state (937+/-93 fs), the CS2 (a) over tilde (3)A(2) state (153+/-10 fs), and the CS2 Rydberg state [(3)/(2)]6ssigma(g) ((3)Pi(g)) (948+/-23 fs) are obtained.

Synthesis and Characterization of Coil-Rod-Coil Triblock Copolymers Comprising Fluorene-Based Mesogenic Monodisperse Conjugated Rod and Poly(ethylene oxide) Coil

A series of coil-rod-coil triblock copolymers (i.e., F3T8EO8, F3T8EO17, F3T8EO45, and F3T8EO125) with a mesogenic monodisperse conjugated oligomer comprising 3 fluorene, 8 thiophene, and 2 phenyl units as the rod and poly(ethylene oxide) (PEO) as the coil were synthesized. A reference compound, that is F3T8ME2, with the identical rod but without PEO was also prepared for comparison. The volume fraction of PEO (f(PEO)) was 0, 0.16, 0.28, 0.50, and 0.73 for F3T8ME2, F3T8EO8, F3T8EO17, F3T8EO45, and F3T8EO125, respectively. It was found that the introduction of PEO into the triblock copolymers encouraged the formation of H-type aggregation and f(PEO)-dependent highly ordered mesophases while f(PEO) < 0.73. For F3T8ME2, only nematic mesophase was observed. In contrast, F3T8EO8 and F3T8EO17, with f(PEO) of 0.16 and 0.28, respectively, are smectic A (SA) mesomorphism.

Structural and Bluish-White Luminescent Properties of Li+-Doped BPO4 as a Potential Environmentally Friendly Phosphor Material

Many efforts have been devoted to exploring novel luminescent materials that not contain expensive or toxic elements, or do not need a mercury vapor plasma source. In this paper, BPO4 and Li+-doped BPO4 powder samples were prepared by the Pechini-type sol-gel (PSG) process. The structure and optical properties of the resulting samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), photoluminescence (PL) excitation and emission spectra, kinetic decay, and X-ray photoelectron spectra (XPS), respectively. It was found that PSG -derived Li+-doped BPO4 annealed at 960 degrees C exhibited bright bluish-white emission centered at 416 nm. The luminescence decay curves analysis indicates that each sample has two kinds of lifetimes (5.9 ns and 0.529 ms) and two types of kinetic decay behaviors which can be fitted into a single-exponential function and a double-exponential function, respectively.

Spatially-confined crystallization of poly(vinylidene fluoride)

Nanometre-sized poly(vinylidene fluoride) (PVDF) particle domains in a confined space were obtained by blending PVDF with excess poly(methyl methacrylate) (PMMA). When these particles were small enough they showed beta -form structure, which was different from the structure of bigger particles or PVDF bulk. However, the beta -form was thermodynamically metastable because it could eventually be transformed to a more stable phase by annealing at a certain temperature. Larger particle domains were of identical phase to the bulk, indicating that small size favours the formation of the beta -form. (C) 2000 Society of Chemical Industry.

An eta(6)-toluene complex of neodymium: [Nd(eta(6)-C6H5CH3)(AlCl4)(3)]

The Nd-III ion in hexa-mu-chloro-1:2 kappa(2)Cl;1:3 kappa(2)Cl;1:4 kappa(2)Cl-hexachloro-2 kappa(2)Cl,3 kappa(2)Cl,4 kappa(2)Cl- [1 (eta(6))- toluene] trialuminiumneodymium has distorted pentagonal bipyramidal coordination geometry. Five Cl atoms form the equatorial plane, and the toluene ring and the sixth Cl atom occupy the apical sites. The average Nd-C(eta(6)) and Nd-Cl distances are 2.926 (5) and 2.857 (1) Angstrom, respectively.

Effects of molecular weight and interaction parameter on the glass transition temperature of polystyrene mixtures and its blends with polystyrene/poly(2,6-dimethyl-p-phenylene oxide)

The glass transition temperature (T-g) of mixtures of polystyrene (PS) with different molecular weight and of blends of poly(2,6-dimethyl-p-phenylene oxide) (PPO) and polystyrene with different molecular weight (DMWPS) was studied by a DSC method. For the whole range of composition, the curves of T-g vs composition obtained by experiment were compared with predictions from the Fox, Gordon-Taylor, Couchman and Lu-Weiss, equations. It was found that the experimental results were not in agreement with those from the Fox, Gordon-TayIor and Couchman equations for the binary mixtures of DMWPS, where the interaction parameter chi was approximately zero. However, for the blends PPO/DMWPS (chi < 0), with an increase of molecular weight of PS, it was shown that the experimental results fitted well with those obtained from the Couchman, Gordon-Taylor and Fox equations, respectively. Furthermore, the Gordon-Taylor equation was nearly identical to the Lu-Weiss equation when \chi\ was not very large. Further, the dependence of the change of heat capacity associated with the glass transition (Delta C-p) on the molecular weight of PS was investigated and an empirical equation was presented. (C) 1997 Elsevier Science Ltd.

STRUCTURE OF THIAMINE BROMIDE SESQUIHYDRATE

3-[(4-Amino-2-methyl-5-pyrimidinyl)-methyl]-5-hydroxyethyl-4-methylthiazolium bromide sesquihydrate, C12H17N4OS+.Br-.1.5H2O, M(r) = 372.28, monoclinic, P2(1)/a, a = 11.676 (2), b = 24.819(7), c = 12.344 (3) angstrom, beta = 113.74(2)-degrees, V= 3274 (1) angstrom3 , Z = 8, D(x) = 1.51 g cm-3 (Mo Kalpha) = 0.71069 angstrom, mu = 26.2 cm-1, F(000) = 1528, T 293 K, R = 0.062 for 2720 observed reflections. Both the independent thiamine molecules A and B in the asymmetric unit adopt the common F conformation. A bromide anion is held by four neighbouring thiamine molecules through C(2)-H...Br hydrogen bonds and Br ... thiazolium-ring electrostatic interactions. Another bromide anion (or a water molecule) bridges the pyrimidine and thiazolium moieties of molecule A (or B) through a hydrogen bond with the amino group and an electrostatic interaction with the thiazolium ring.

Isolation and characterization of microsatellites in yellow perch (Perca flavescens)

A total of 45 microsatellite loci from yellow perch, Perca flavescens, were isolated and characterized. Among the 45 microsatellite loci, 32 had more than two alleles. A wild population of P. flavescens (n = 48) was used to examine the allele range of the microsatellite loci. Mendelian inheritance of alleles was confirmed by examining the amplified products in pair-mated families. The number of alleles for the 32 polymorphic loci varied from two to 16, and observed heterozygosity ranged between 0.024 (YP79) and 0.979 (YP60). Cross-species polymorphic amplification in four other Percidae species was successful for 22 loci.

The preparation and stability of the inclusion complex of astaxanthin with beta-cyclodextrin

Inclusion complex of astaxanthin with beta-cyclodextrin was prepared. The water solubility of the inclusion complex was < 0.5 mg/ml, which is better than that of astaxanthin. Large aggregates were observed in the aqueous solution of the inclusion complex. Furthermore, the stability of the inclusion complex against temperature and light was greatly enhanced compared to that of astaxanthin. (c) 2006 Elsevier Ltd. All rights reserved.