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71.
Weber T Czasch A Jagutzki O Müller A Mergel V Kheifets A Feagin J Rotenberg E Meigs G Prior MH Daveau S Landers AL Cocke CL Osipov T Schmidt-Böcking H Dörner R 《Physical review letters》2004,92(16):163001
We report the first kinematically complete study of the four-body fragmentation of the D2 molecule following absorption of a single photon. For equal energy sharing of the two electrons and a photon energy of 75.5 eV, we observed the relaxation of one of the selection rules valid for He photo-double-ionization and a strong dependence of the electron angular distribution on the orientation of the molecular axis. This effect is reproduced by a model in which a pair of photoionization amplitudes is introduced for the light polarization parallel and perpendicular to the molecular axis. 相似文献
72.
We present a calculation of the B0-B(-)0 mixing matrix element in the framework of QCD sum rules for three-point functions. We compute alpha(s) corrections to a three-point function at the three-loop level in QCD perturbation theory, which allows one to extract the matrix element with next-to-leading order (NLO) accuracy. This calculation is imperative for a consistent evaluation of experimentally measured mixing parameters since the coefficient functions of the effective Hamiltonian for B0-B(-)0 mixing are known at NLO. We find that radiative corrections violate factorization at NLO; this violation is under full control and amounts to 10%. The resulting value of the B parameter is found to be B(B)(m(b))=1+0.1(PT)-0.05(non-PT). 相似文献
73.
Reversible addition-fragmentation chain transfer (RAFT) radical polymerisation enables to synthesise well-defined homopolymers and block copolymers based on 2-(acetoacetoxy)ethyl methacrylate, which are capable to strongly coordinate to metals and metal ions. 相似文献
74.
Scarpellini M Neves A Hörner R Bortoluzzi AJ Szpoganics B Zucco C Nome Silva RA Drago V Mangrich AS Ortiz WA Passos WA de Oliveira MC Terenzi H 《Inorganic chemistry》2003,42(25):8353-8365
The tridentate Schiff base [(2-(imidazol-4-yl)ethyl)(1-methylimidazol-2-yl)methyl)imine (HISMIMI) and its reduced form HISMIMA were synthesized and characterized, as well their mononuclear cis-dihalo copper(II) complexes 1 and 2, respectively. In addition, the dinuclear [CuII(mu-OH)2CuII](2+) complexes (3) and (4) obtained from complexes 1 and 2, respectively, were also isolated and characterized by several physicochemical techniques, including magnetochemistry, electrochemistry, and EPR and UV-vis spectroscopies. The crystal structures of 1 and 2 were determined by X-ray crystallography and revealed two neutral complexes with their tridentate chelate ligands meridionally coordinated. Completing the coordination spheres of the square-pyramidal structures, a chloride ion occupies the apical position and another is bonded in the basal plane. In addition, complexes 1 and 2 were investigated by infrared, electronic, and EPR spectroscopies, cyclic voltammetry, and potentiometric equilibrium studies. The hydrolytic activity on phosphate diester cleavage of 1 and 2 was investigated utilizing 2,4-BDNPP as substrate. These experiments were carried out at 50 degrees C, and the data treatment was based on the Michaelis-Menten approach, giving the following kinetic parameters (complex 1/complex 2): vmax (mol L(-1) s(-1))=16.4x10(-9)/7.02x10(-9); KM (mol L(-1))=17.3x10(-3)/3.03x10(-3); kcat (s(-1))=3.28x10(-4)/1.40x10(-4). Complex 1 effectively promoted the hydrolytic cleavage of double-strand plasmid DNA under anaerobic and aerobic conditions, with a rate constant of 0.28 h(-1) for the decrease of form I, which represents about a 10(7) rate increase compared with the estimated uncatalyzed rate of hydrolysis. 相似文献
75.
Leonardo C. Ferreira Carlos A. L. Filgueiras Lorenzo C. Visentin Jairo Bordinho Manfredo Hrner 《无机化学与普通化学杂志》2008,634(11):1896-1900
The preparation and characterization of two novel HgCl2 and Hg(SCN)2 complexes with bis[N‐(2‐tert‐butylphenyl)imine]acenaphthene is here described. One‐pot reaction techniques were used, leading to high yields of 75 % and 81 %, respectively. The complexes were characterized by microanalysis, i.r. and 1HNMR spectroscopy, and by single crystal X‐ray diffraction. The structures of the complexes present similar characteristics, the most outstanding being the formation of dimers via intermolecular interaction. Whereas the HgCl2 complex shows a unidimensional network due to strong π–π interactions, its Hg(SCN)2 counterpart displays a supramolecular arrangement resulting from non classical hydrogen bond formation. 相似文献
76.
77.
Ohne Zusammenfassung 相似文献
78.
E. Wörner 《Fresenius' Journal of Analytical Chemistry》1900,39(3):197-198
Ohne Zusammenfassung 相似文献
79.
80.
Ohne Zusammenfassung 相似文献