Near IR laser light visualizators using nonlinear GaSe and other layered crystallites

Two methods of preparation of the devices for visualization of pulsed and continuous near-IR (near infrared) are described and the results of conversion of pulsed and continuous IR (800–1360 nm) laser radiation into the visible range of spectra (400–680 nm) by using a transparent substrate covered with the particles (including nanoparticles) of effective nonlinear materials of GaSe _x S_{1 − x} (0.2 ≤ x ≤ 0.8) are presented. Converted light can be detected in transmission or reflection geometry as a visible spot corresponding to the real size of the incident laser beam. Developed device structures can be used for checking if the laser is working or not, for optical adjustment, for visualization of distribution of laser radiation over the cross of the beam and for investigation of the content of the laser radiation. Low energy (power density) limit for visualization of the IR laser pulses with 2–3 ps duration for these device structures are: between 4.6–2.1 μJ (3 × 10⁻⁴−1 × 10⁻⁴ W/cm²) at 1200 nm; between 8.4–2.6 μJ (4.7 × 10⁻⁴−1.5 × 10⁻⁴ W/cm²) at 1300 nm; between 14.4–8.1 μJ (8.2 × 10⁻⁴–4.6 × 10⁻⁴ W/cm²) at 1360 nm. Threshold damage density is more than 10 MW/cm² at λ = 1060 nm, pulse duration τ = 35 ps. The results are compared with commercially existing laser light visualizators.     

Preparation of complexes of 1-amino-6,7-O-cyclohexylidene-4-azaheptane with transition metal acetates

1-Amino-6,7-O-cyclohexylidene-4-azaheptane (L) has been synthesized starting from 1-chloro-2,3-O-cyclohexylidenepropane prepared by the reaction of epichlorohydrin with cyclohexanone, catalyzed by BF₃OEt₂. Complexes of this ligand with Co(II), Ni(II) and Cu(II) acetates were prepared. The structures of the ligand and its complexes are proposed based on the elemental analyses, IR, UV-VIS, and ¹H and ¹³C NMR spectra, magnetic susceptibilities, and conductomety data.     

On Lie ideals with generalized derivations

Let R be a prime ring with characteristic different from 2, let U be a nonzero Lie ideal of R, and let f be a generalized derivation associated with d. We prove the following results: (i) If a ∈ R and [a, f(U)] = 0 then a ∈ Z or d(a) = 0 or U ? Z; (ii) If f ²(U) = 0 then U ? Z; (iii) If u ² ∈ U for all u ∈ U and f acts as a homomorphism or antihomomorphism on U then either d = 0 or U ? Z.     

Weakly ferromagnetic microspheres bearing paramagnetic CrBO3 core and nonmagnetic polyvinylbutyral shell

A new class of core–shell microspheres was prepared through a modified solvent evaporation technique by coating chromium orthoborate (CrBO₃) particles with a commercial resin, namely Mowital®B30HH (polyvinyl butyral, PVB). Well‐shaped spherical particles were obtained in diameters ranging from 40 to 420 µm. The morphological, structural, thermal, and magnetic properties were characterized by SEM, FTIR, UV–Vis, VSM (Vibrating Sample Magnetometry), and thermal analysis techniques. Uncoated CrBO₃ is paramagnetic at room temperature and antiferromagnetic at low temperatures (T_N = 12 K) while PVB itself is nonmagnetic at room temperature. The results indicated that the microspheres having a paramagnetic core and nonmagnetic shell displayed weakly ferromagnetic properties at room temperature. The observed ferromagnetism was correlated with the particle size and higher saturation magnetization values were achieved with smaller microspheres. This unconventional magnetic behavior can be tuned by varying the particle size and may allow CrBO₃/PVB microspheres to serve as a smart material in future applications. Copyright © 2009 John Wiley & Sons, Ltd.     

Novel Molecular Building Blocks Based on the Boradiazaindacene Chromophore: Applications in Fluorescent Metallosupramolecular Coordination Polymers

Bright polymers : Fluorescent coordination polymers made up of versatile functionalized bodipy (boron‐dipyrrin) chromophore building blocks, such as that depicted, are described. Polymerization is signaled by changes in fluorescence emission intensity and shifts in peak emission wavelengths.

     

Pressure dependence of the electron-phonon interaction derived from normal state resistivity: Al and Pb

It is suggested that the pressure dependence of the electron-phonon coupling, λ, and the normal state temperature derivative of resistivity, d?/dT, are related by the simple expression d ln λ/dp=d ln (d?/dT)/dp. Published results support this relation for Al and Pb.     

Safflower seed oil of Turkish origin as a diesel fuel alternative

Applied Biochemistry and Biotechnology - Among the biomass resources, vegetable oils seem to have the potential to be used as fuel alternatives for diesel engines. The major restricting factor in...     

Electrophilic substitution reactions of indole alkaloids with α,β-unsaturated carbonyl compounds in the presence of K10 montmorillonite

Reactions of indole, 1-methylindole, and 3-methylindole with dimethyl acetylenedicarboxylate in the presence of K10 montmorillonite as a catalyst led to the formation of the corresponding dimethyl 2,2-bis(indolyl)butanedioates. The reaction of 2-methylindole with dimethyl acetylenedicarboxylate gave dimethyl 2-(2-methyl-1H-indol-3-yl)maleate and dimethyl 2-methyl-1H-1-benzoazepine-3,4-dicarboxylate. Dimethyl 1,5-dimethyl-1H-1-benzoazepine-3,4-dicarboxylate was obtained by treatment of 1,3-dimethylindole with dimethyl acetylenedicarboxylate using K10 clay as a catalyst. Published in Russian in Zhurnal Organicheskoi Khimii, 2006, Vol. 42, No. 6, pp. 900–902. The text was submitted by the authors in English.     

Chemical effects on L shell fluorescence yields of Ba, La and Ce compounds

Chemical effects on the average L shell fluorescence yields (v_L) for Ba, La and Ce compounds were investigated. Samples were excited by gamma-rays with 59.5 keV energy photons from a ²⁴¹Am radioisotope source. L X-rays emitted by samples were counted by a Si(Li) detector with a resolution 155 eV at 5.9 keV. Chemical effects on the average L shell fluorescence yield (v _L) for Ba, La and Ce compounds were observed. The values are compared with theoretical and experimental ones for the pure elements.