| 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. |
- Chen, Ruikui, et al.
(författare)
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Photoinduced intramolecular charge-transfer state in thiophene-π-conjugated donor-acceptor molecules.
- 2008
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Ingår i: Journal of Molecular Structure. - : Elsevier BV. - 0022-2860 .- 1872-8014. ; 876:1-3, s. 102-109
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Tidskriftsartikel (refereegranskat)abstract
- Novel thiophene-π-conjugated donor-acceptor mols., 5-[2-(1,2,2,4-tetramethyl-1,2,3,4-tetrahydroquinolin-6-yl)-vinyl]-thiophene-2-carbaldehyde (QTC) and (1-cyano-2-{5-[2-(1,2,2,4-tetramethyl-1,2,3,4-tetrahydroquinolin-6-yl)-vinyl]-thiophen-2-yl}-vinyl)-phosphonic acid di-Et ester (QTCP), were designed and synthesized. Combined exptl. and theor. methods were performed to investigate the photoinduced intramol. charge-transfer (ICT) processes of these compds. Steady-state absorption and fluorescence measurements in different solvents indicate the photoinduced ICT characters of QTC and QTCP. Solvent dependency of the large Stokes shifts and high dipole moment of the excited state also support the charge-transfer character of the excited state. Theor. calcns. based on time-dependent d. functional theory (TDDFT) method were performed to investigate ICT states of these compds. The results reveal that the excited states have adopted a distortion of the C=C double bond between the donor moiety and the thiophene-π-bridge. [on SciFinder(R)]
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| 3. |
- Sun, Jielin, et al.
(författare)
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Evidence for two independent prostate cancer risk-associated loci in the HNF1B gene at 17q12
- 2008
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Ingår i: Nature Genetics. - London : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 40:10, s. 1153-1155
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We carried out a fine-mapping study in the HNF1B gene at 17q12 in two study populations and identified a second locus associated with prostate cancer risk, 26 kb centromeric to the first known locus (rs4430796); these loci are separated by a recombination hot spot. We confirmed the association with a SNP in the second locus (rs11649743) in five additional populations, with P = 1.7 10-9 for an allelic test of the seven studies combined. The association at each SNP remained significant after adjustment for the other SNP.
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| 4. |
- Sun, S. G., et al.
(författare)
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Studies of a series of novel rhenium(I) bipyridyl dyes for solar cells
- 2005
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Ingår i: Chinese Chemical Letters. - 1001-8417 .- 1878-5964. ; 16:5, s. 677-680
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Tidskriftsartikel (refereegranskat)abstract
- A series of novel rhenium(I) 2,2'-bipyridyl complexes [fac-Re(4,4'-di-COOEt-bpy)-(CO)(3)(Xpy)PF6], where bpy is 2,2'-bipyridine, py is pyridine and X is 3-methyl, 3-hydroxy, or 3-amino, were synthesized, their photophysical and electrochemical properties were studied. The Re(II/I) oxidation potentials decreased as the X group becomes more electron donating from H to 3-methyl, 3-hydroxy, or 3-amino, which might be a very convenient ways for adjusting the electron transfer driving force.
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| 5. |
- Zhao, Guang-Jiu, et al.
(författare)
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Photoinduced intramolecular charge transfer and S-2 fluorescence in thiophene-pi-conjugated donor-acceptor systems : Experimental and TDDFT studies
- 2008
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 14:23, s. 6935-6947
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Tidskriftsartikel (refereegranskat)abstract
- Experimental and theoretical methods were used to study newly synthesized thiophene-pi-cojugated donor-acceptor compounds, which were found to exhibit efficient intramolecular charge-transfer emission in polar solvents with relatively large Stokes shifts and strong solvatochromism. To gain insight into the solvatochromic behavior of these compounds, the dependence of the spectra on solvent polarity was studied on the basis of Lippert-Mataga models. We found that intramolecular charge transfer in these donor-acceptor systems is significantly dependent on the electron-with-drawing substituents at the thienyl 2-position. The dependence of the absorption and emission spectra of these compounds in methanol on the concentration of trifluoroacetic acid was used to confirm intramolecular charge-tranfer emission. Moreover, the calculated absorption and emission energies, which are in accordance with the experimental values, suggested that fluorescence can be emitted from different geometric confirmations. In addition, a novel S-2 fluorescence phenomenon for some of these compounds was also be observed. The fluorescence excitation spectra were used to confirm the S-2 fluorescence. We demonstrate that S-2 fluorescence can be explained by the calculated energy gap between the S-2 and S-1 states of these molecules. Furthermore, nonlinear optical behavior of the thiophene-pi-conjugated compound with diethylcyanomethylphosphonate substituents was predicted in theory.
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| 6. |
- Zhu, Bin, et al.
(författare)
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Compatible cathode materials for high performance low temperature (300-600°C) solid oxide fuel cells
- 2006
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Ingår i: Proceedings of 4th International ASME Conference on Fuel Cell Science, Engineering and Technology, FUELCELL2006. - : ASMEDC. - 0791837807 - 9780791837801
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Konferensbidrag (refereegranskat)abstract
- We have made extensive efforts to develop various compatible electrode materials for the ceria-based composite (CBC) electrolytes, which have been, reported as most advanced LTSOFC electrolyte materials (Zhu, 2003). The electrode materials we have investigated can be classified as four categories: i) LSCCF (LaSrCoCaFeO) and BSCF perovskite oxides applied for our CBC electrolyte LTSOFCs; ii) LFN (LaFeO-based oxides, e.g. LaFe0.8Ni 0.2O3) perovskite oxides; iii) lithiated oxides: e.g. LiNiOx, LiVOx or LiCuOx are typical cathode examples for the CBC LTSOFCs; iv) other mixed oxide systems, most common in a mixture of two-oxide phases, such CuOx-NiOx, CuO-ZnO etc. systems with or without lithiation are developed for the CBC systems, especially for direct alcohol LTSOFCs. These cathode materials used for the CBC electrolyte LTSOFCs have demonstrated excellent performances at 300-600°C, e.g. 1000 mWcm-2 was achieved at 580°C. The LTSOFCs can be operated with a wide range of fuels, e.g. hydrogen, methanol, ethanol etc with great potential for applications.
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| 7. |
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| 8. |
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| 9. |
- Gao, Aiping, et al.
(författare)
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Asymmetric oxidation of sulfides catalyzed by chiral (salen)Mn(III) complexes with a pyrrolidine backbone
- 2006
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Ingår i: Applied organometallic chemistry. - : Wiley. - 0268-2605 .- 1099-0739. ; 20:12, s. 830-834
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Tidskriftsartikel (refereegranskat)abstract
- Catalytic properties of a series of chiral (pyrrolidine salen)Mn(III) complexes for asymmetric oxidation of aryl methyl sulfides were evaluated. Moderate activity, good chemical selectivity and low enantioselectivity were attained with iodosylbenzene as a terminal oxidant. Enantioselectivity of sulfide oxidation was affected slightly by polar solvent and the sulfoxidation carried out in THF for thioanisole and in CH3CO2Et for electron-deficient sulfides gave better enatioselctivities. The addition of the donor ligand PPNO (4-phenylpyridine N-oxide) or MNO (trimethylamine N-oxide) only has a minor positive effect on the enantioselectivity. Also explored was the steric effect of the N-aza-substituent in the backbone of (pyrrolidine salen)Mn(III) complexes on the enantioselectivity of sulfide oxidation. The sulfides' access pathway is discussed based on the catalytic results.
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| 10. |
- Gao, Aiping, et al.
(författare)
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Asymmetric oxidation of sulfides catalyzed by vanadium(IV) complexes of dibromo- and diiodo-functionalized chiral Schiff bases
- 2006
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Ingår i: Cuihuà xuébào. - 0253-9837 .- 1872-2067. ; 27:8, s. 743-748
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Tidskriftsartikel (refereegranskat)abstract
- The catalyst system of VO(acac)(2) and Schiff base ligands derived from 3,5-dibromo- or 3,5-diiodosalicylaldehyde and inexpensive chiral amino alcohols was prepared. This catalyst displayed good yields and moderate to high enantioselectivity for the asymmetric oxidation of aryl methyl sulfides at room temperature when 1% catalyst (VO(acac)(2)/ligand molar ratio of 1: 2) and H2O2 Oxidant were used. The ligands derived from ( S)valinol exhibited considerably higher enantioselectivity than those ligands derived from ( S)-phenylalaninol and (R)-leucinol. The enantiomeric excess values were improved up to 88% for methyl phenyl sulfoxide and 92% for methyl p-bromophenyl sulfoxide by slow dropwise addition of H2O2 with the ligand prepared from 3 15-diiodosalicylaldehyde and (s)-valinol. The present study showed that the catalytic efficiency of VO(acac)(2) /Schiff base systems could not be improved by the addition of carboxylic acids or carboxylate salts.
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