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101.
Aubert B Bona M Boutigny D Karyotakis Y Lees JP Poireau V Prudent X Tisserand V Zghiche A Garra Tico J Grauges E Lopez L Palano A Eigen G Stugu B Sun L Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Groysman Y Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Lopes Pegna D Lynch G Mir LM Orimoto TJ Ronan MT Tackmann K Wenzel WA del Amo Sanchez P Hawkes CM Watson AT Held T Koch H Lewandowski B Pelizaeus M Schroeder T Steinke M Walker D Asgeirsson DJ Cuhadar-Donszelmann T Fulsom BG 《Physical review letters》2007,99(20):201802
We perform an amplitude analysis of B+/--->phi(1020)K*(892)+/- decay with a sample of about 384 x 10(6) BB[over ] pairs recorded with the BABAR detector. Overall, twelve parameters are measured, including the fractions of longitudinal fL and parity-odd transverse f perpendicular amplitudes, branching fraction, strong phases, and six parameters sensitive to CP violation. We use the dependence on the Kpi invariant mass of the interference between the JP=1(-) and 0+ Kpi components to resolve the discrete ambiguity in the determination of the strong and weak phases. Our measurements of fL=0.49+/-0.05+/-0.03, f perpendicular=0.21+/-0.05+/-0.02, and the strong phases point to the presence of a substantial helicity-plus amplitude from a presently unknown source. 相似文献
102.
Araújo MJ Mattar NS Reis AS Serra IC Fialho EM Assunção AK Dutra RP Nogueira AM Libério SA Guerra RN Lopes AS Ribeiro MN Nascimento FR 《Natural product research》2011,25(11):1037-1046
The propolis of Scaptotrigona aff. postica is popularly used in Maranh?o State, Brazil, for treating wounds and respiratory illnesses. Nevertheless, little is known about the chemical composition of this propolis and the adverse effects of its use. Hence, this study is a pharmacognostic characterisation of the propolis hydroalcoholic extract (PHE) from S. aff. postica. The methodology consisted of an evaluation of the sensory and chemical parameters. Chemical analysis of PHE indicated high concentrations of phenolic and triterpens substances, and the absence of steroids. Additionally, we evaluated the acute toxicity of propolis using 48 Swiss male and female mice. The animals received single doses of PHE (1000, 2000 or 4000 mg kg?1) orally and were observed for 14 days. After this period, the mice were sacrificed and the blood was used for biochemical and haematological evaluation. PHE did not induce any death, and the acute treatment significantly reduced serum concentrations of alanine aminotransferase and alkaline phosphatase. The resultant data indicate that PHE from S. aff. postica has low toxicity when used orally, even in high doses. 相似文献
103.
Teresa M V D Pinho e Melo Cláudia S J Lopes António M d'A Rocha Gonsalves Ana M Beja José A Paix?o Manuela R Silva Luiz Alte da Veiga 《The Journal of organic chemistry》2002,67(1):66-71
Nucleophilic substitution reactions of 2-halo-2H-azirines 1a, 1b, 1d, and 1e with potassium phthalimide and aniline allowed the preparation of new substituted 2H-azirines 2-5. The reactions of 2-bromo-2H-azirine 1a with methylamine led to the synthesis of alpha-diimines 7 and 8. 2-Halo-2H-azirines were also established as building blocks for the synthesis of a range of heterocyclic compounds, namely, quinoxalines 10a-10d, 3-oxazoline 14, and 2H-[1,4]oxazines 18 and 20. X-ray crystal structures of alpha-diimine 7, 3-oxazoline 14, and 2H-[1,4]oxazine 18 are reported. 相似文献
104.
This paper describes a methodology for adapting the acoustoultrasonic technique for use in monitoring structures or mechanical
components. As a practical example, the adaptation of the technique for monitoring fatigue tests on front suspension arms
is considered. From this particular example, it will be shown that the procedure is suitable for application to more general
cases. The results of a number of fatigue tests carried out at the Fiat Research Center on a typical component test rig are
also presented. 相似文献
105.
106.
Robert Vestberg Christina Nilsson Cesar Lopes Per Lind Bertil Eliasson Eva Malmstrm 《Journal of polymer science. Part A, Polymer chemistry》2005,43(6):1177-1187
The synthesis and characterization of dendron‐coated 2,5‐bis(phenylethynyl)thiophene chromophores are described. The dendrimers were grown divergently on the arylthiophene core with the versatile anhydride of 2,2‐bis(methylol)propionic acid. The arylthiophene core was synthesized with Sonogashira coupling reactions. Structurally well‐defined dendrimers up to the fourth generation were grown, as confirmed by size exclusion chromatography, NMR, and matrix‐assisted laser desorption/ionization time‐of‐flight analysis. The different dendritic substitution did not influence the absorption spectra of the compounds in or near the visible region. Solutions of arylthiophenes had good transparency at wavelengths greater than 400 nm. The dendritic thiophenes exhibited an optical‐power limit at the laser wavelength of 532 nm. However, the magnitude of the optical‐power limit of these compounds was slightly lower than that of a nondendritic arylthiophene with n‐pentyl substituents. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1177–1187, 2005 相似文献
107.
108.
L. Ferreira-Mendonça V. L. R. Lopes J. M. Martínez 《Computational Optimization and Applications》2008,40(3):373-388
Optimality (or KKT) systems arise as primal-dual stationarity conditions for constrained optimization problems. Under suitable
constraint qualifications, local minimizers satisfy KKT equations but, unfortunately, many other stationary points (including,
perhaps, maximizers) may solve these nonlinear systems too. For this reason, nonlinear-programming solvers make strong use
of the minimization structure and the naive use of nonlinear-system solvers in optimization may lead to spurious solutions.
Nevertheless, in the basin of attraction of a minimizer, nonlinear-system solvers may be quite efficient. In this paper quasi-Newton
methods for solving nonlinear systems are used as accelerators of nonlinear-programming (augmented Lagrangian) algorithms,
with equality constraints. A periodically-restarted memoryless symmetric rank-one (SR1) correction method is introduced for
that purpose. Convergence results are given and numerical experiments that confirm that the acceleration is effective are
presented.
This work was supported by FAPESP, CNPq, PRONEX-Optimization (CNPq / FAPERJ), FAEPEX, UNICAMP. 相似文献
109.
Karine L Marques Jo?o L M Santos Jo?o A Lopes José L F C Lima 《Analytical sciences》2008,24(8):985-991
An automated multi-pumping flow system is proposed for the simultaneous chemiluminometric determination of benserazide and levodopa using multivariate calibration methods. The developed methodology is based on chemiluminescence (CL) emission generated by the reaction of benserazide with luminol, and on a concurrent inhibiting effect of levodopa on this reaction. A multi-pumping flow system comprising multiple solenoid micro-pumps as the only active components was developed to implement a stopped-flow approach for signal acquisition and processing. Artificial neural networks were used to establish a relationship between the CL emission profile and the concentration of both drugs. The concentration values used to establish the experimental calibration samples were varied between 5 and 30 mg l(-1) for levodopa and between 2.5 and 20 mg l(-1) for benserazide. The proposed method was successfully applied to the simultaneous determination of levodopa and benserazide in pharmaceutical formulations combining both drugs. 相似文献
110.