| 1. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 2. |
- Hu, Xia-lin, et al.
(författare)
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Evaluating the impacts of some environmentally relevant factors on the availability of bisphenol A with negligible-depletion SPME
- 2006
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Ingår i: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 65:11, s. 1935-1941
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Tidskriftsartikel (refereegranskat)abstract
- The effect of some environmentally relevant factors including salinity, pH, and humic acids on the availability of bisphenol A (BPA) was evaluated by using the negligible-depletion solid-phase microextraction (nd-SPME) biomimetic method. With the variation of salinity (0-500 mM NaCl) and pH (5.0-8.5) of aqueous solutions, the partition coefficients of BPA between the nd-SPME fiber and the aqueous solution varied in the range of logD = 3.55-3.86, which indicates that the salinity and pH can influence the availability of BPA. By using Acros humic acid as model dissolved organic matter (DOM), it was also demonstrated that the environmental factors such as salinity and pH could affect the partitioning of BPA between DOM and aqueous solutions. The determined partition coefficients of BPA between dissolved organic carbon (DOC) and aqueous solutions were in the range of log D-DOC = 4.03-5.60 for Acros humic acid solutions with 1-50 mg l(-1) DOC. The influence of salinity and pH on log D-DOC was more significant at low concentration (0-5 mg l(-1)) of DOC. (c) 2006 Elsevier Ltd. All rights reserved.
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| 3. |
- Liu, Jing-fu, et al.
(författare)
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Equilibrium sampling of freely dissolved alkylphenols into a thin film of 1-octanol supported on a hollow fiber membrane
- 2006
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 78:24, s. 8526-8534
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Tidskriftsartikel (refereegranskat)abstract
- A new negligible depletion extraction procedure was proposed for equilibrium sampling of 4-tert-octylphenol (OP) and 4-nonylphenol (NP) into a thin film of 1-octanol supported on a hollow fiber membrane. This thin liquid film extraction technique was directed at the determination of ( 1) freely dissolved concentrations, ( 2) distribution coefficients to 1-octanol (D-ow), and ( 3) binding to dissolved organic matter (D-DOC). The sampling device was prepared by dipping pieces of polypropylene microporous hollow fiber membrane (10-mm length, 30-mu m wall thickness, 240-mu m inner diameter) into 1-octanol for a few seconds to impregnate the pores of the hollow fiber wall. After stirring in 100 mL of sample solution for 24 h, the sampling device was harvested and desorbed with 30 mu L of methanol, of which 20 mu L was injected for HPLC analysis. With the measured Dow of a chemical and its equilibrium concentration in the 1-octanol sampling phase (C-octanol), the freely dissolved concentration (C-free) was calibrated based on C-free = C-octanol/D-ow. Measured log D-ow values of OP (4.32 +/- 0.06) and NP (4.79 +/- 0.02) were independent of the chemical concentration, only minimally affected by the environmentally relevant pH, buffering capacity, and salinity of samples, and agreed well with reported values. Log D-DOC values of OP (4.89 +/- 0.43) and NP (5.14 +/- 0.37), determined in Aldrich humic acid solution, agreed with reported partition coefficients to organic carbon ( log K-oc) for particles in river water and effluent wastewater. Short equilibration times and high enrichment factors were obtained for both analytes due to the high surface to volume ratio of the new sampler. The technique was successfully applied to determine C-free of OP and NP in real water samples and to study their association with humic acids and bovine albumin.
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| 4. |
- Tian, Yu-Peng, et al.
(författare)
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Investigations and facile synthesis of a series of novel multi-functional two-photon absorption materials
- 2007
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Ingår i: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 0959-9428 .- 1364-5501. ; 17:34, s. 3646-3654
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Tidskriftsartikel (refereegranskat)abstract
- Six centrosymmetric D-(pi-A)(3) structural triphenylamine derivatives that can be used as two- photon photopolymerization and optical data storage chromophores, tris[ 4-( 4- pyridylethenyl) phenyl] amine ( 1), tris[ 4-( 2- pyridylethenyl) phenyl] amine ( 2), tris( 4- cyanoethenylphenyl) amine ( 3), tris[ 4- butylacrylatephenyl] amine ( 4), tris[ 4- methylacrylatephenyl] amine ( 5) and tris[ 4- acrylicethenylphenyl] amine ( 6), have been successfully synthesized via a triple palladium-catalyzed Heck coupling reaction, and the novel chromophores were fully characterized by elemental analysis, IR, (1)H-NMR and ESIMS. The structure for 3 was determined by single crystal X-ray diffraction study. One- and two-photon absorption and fluorescence in various solvents were experimentally investigated. Two-photon initiated polymerization microfabrication and optical data recording experiments were carried out under 780 nm laser radiation, and the possible polymerization mechanism is discussed based on theoretical calculations. All the six chromophores have relatively large two-photon absorption crosssections, and exhibit optical memory and highly efficient two-photon initiated polymerization abilities.
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| 5. |
- Tian, Yu-peng, et al.
(författare)
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Synthesis, crystal structure and NLO properties of a novel ruthenium(II) complex with unusual coordination mode
- 2005
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Ingår i: Transition metal chemistry (Weinheim). - : Kluwer Academic Publishers. - 0340-4285 .- 1572-901X. ; 30:7, s. 778-785
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Tidskriftsartikel (refereegranskat)abstract
- A new Schiff base 4-[N-hydroxyethyl-N-(methyl)amino]benzaldehyde S-methyl dithiocarbazate (HL, where H is a dissociable proton) and the ruthenium complex [Ru(bpy)2L]PF6 (bpy = 2,2′-bipyridine) have been synthesized. The structural determinations of the ligand and its ruthenium complex, by X-ray crystallography, show that the ligand is coordinated as a monoanionic bidentate N, S-donor, forming a four-member chelate ring with a bite angle of 65.91°. The complex shows intense MLCT transitions in the visible region. Fluorescent and electrochemical properties have been also studied. The complex in DMF solution exhibited a strong two-photon absorption (t.p.a.) at 532 nm nanosecond laser pulses. The t.p.a. coefficient β, t.p.a. cross-section σ and the third-order optical nonlinearity χ(3) of the complex and the ligand have been determined by the Z-scan technique.
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| 6. |
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