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51.
Low-power cw lasers are employed to study grating formation in blue-phase liquid crystals. We observed that undoped samples exhibit vanishingly small optical nonlinearities whereas methyl-red-dye doped samples produce strong nonlinear self-diffraction effects. The nonlinearities are attributed to director axis reorientation, disorder, and lattice distortion by the laser-excited dye molecules. The magnitude of the observed intensity-dependent index coefficient is in the range of 10-4-10-3 cm2/Watt. 相似文献
52.
Solid phase extraction (SPE) using Sep-Pak? cartridges is one of the techniques used for fractionation of antioxidant compounds in waste of dabai oil extraction (defatted dabai parts). The aim of this study was to determine the phenolic compounds and antioxidant capacity in crude extracts and several SPE fractions from methanolic extract of defatted dabai pulp and peel. Based on SPE, Sep-Pak? cyanopropyl and C18 cartridges were used to fractionate the antioxidant-rich crude extracts into water and methanolic fractions. Analyzed using LC-MS, flavonoids, anthocyanins, saponin derivatives and other unknown antioxidative compounds were detected in the defatted dabai crude extracts and their SPE fractions. Anthocyanins were the major phenolic compounds identified in the defatted dabai peel and detected in most of the SPE fractions. Methanolic fractions of defatted dabai parts embraced higher total phenolics and antioxidant capacity than water fractions. This finding also revealed the crude extracts of defatted dabai peel have the most significant antioxidant properties compared to the methanolic and water fractions studied. The crude extract of defatted dabai parts remain as the most potent antioxidant as it contains mixture of flavonoids, anthocyanins and other potential antioxidants. 相似文献
53.
Ann Ling Tan Li Jian Khoo Siti Salwa Alias Ahmad Azmin Mohamad 《Journal of Sol-Gel Science and Technology》2012,64(1):184-192
This work presents a photo electrochemical cell based on zinc oxide (ZnO) nanoparticles and poly(acrylic) acid (PAA) doped with sodium iodide (NaI) and iodine (I2) polymer gel electrolyte. The ZnO powders were synthesized by sol–gel storage and sol–gel centrifugation. The ZnO powder synthesized via sol–gel centrifugation showed the optimal structural properties, with largest crystallite sizes of 58 nm, average particles size between 20 and 80 nm and indirect band gap energy of 3.20 eV. The highest conductivity [(8.0 ± 0.1) × 10?2 S cm?1] was obtained for PAA + 0.8 M NaI + 0.02 M I2. This sample achieved the lowest activation energy (0.029 eV) and electrochemical stability at 1.6 V. The ZnO powder synthesized via sol–gel centrifugation and PAA + 0.8 M NaI + 0.02 M I2 was fabricated as a Cu–ZnO/PAA + 0.8 M NaI + 0.02 M I2/C-ITO photo electrochemical cell. 相似文献
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J.P. Seitz B.B. Back M.P. Carpenter I. Diszegi K. Eisenman P. Heckman D.J. Hofman M.P. Kelly T.L. Khoo S. Mitsuoka V. Nanal T. Pennington R.H. Siemssen M. Thoennessen R.L. Varner 《Nuclear Physics A》2005,750(2-4):245-255
The giant dipole resonance built on excited states was observed in very fissile nuclei in coincidence with evaporation residues. The reaction 48Ca + 176Yb populated evaporation residues of mass A=213–220 with a cross section of 200 μb at 259 MeV. The extracted giant dipole resonance parameters are in agreement with theoretical predictions for this mass region. 相似文献
56.
E.F. Moore M.P. Carpenter R.V.F. Janssens T.L. Khoo T. Lauritsen D. Ackermann I. Ahmad H. Amro D. Blumenthal S. Fischer G. Hackman D. Nisius F. Hannachi A. Lopez-Martens S. J. Asztalos R.M. Clark M.A. Deleplanque R.M. Diamond P. Fallon R. Krueken I-Y. Lee A.O. Macchiavelli F.S. Stephens J.A. Becker L. Bernstein L.P. Farris E.A. Henry A. Korichi 《Zeitschrift für Physik A Hadrons and Nuclei》1997,358(2):219-223
The lifetimes of states in Superdeformed (SD) bands in 192,194Hg have been measured using the Doppler shift attenuation method. Intrinsic quadrupole moments have been extracted for band 1 of 192Hg and for bands 1, 2, and 3 of 194Hg. It was found that the quadrupole moments for the “identical” SD bands in these nuclei are the same. In the same experiment, one-step transitions linking SD states to yrast and near yrast states for bands 1 and 3 of 194Hg have been identified. From this observation, excitation energies, spins and probable parities have been assigned to SD states in these bands. 相似文献
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