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731.
A nonconvex programming problem, which arises in the context of application of Benders' decomposition procedure to a class of network optimization problems, is considered. Conditions which are both necessary and sufficient for a local maximum are derived. The concept of a basic local maximum is introduced, and it is shown that there is a finite number of basic local maxima and at least one such local maximum is optimal. 相似文献
732.
Summary of the fifth international workshop on slow positron beam techniques for solids and surfaces
733.
734.
Pyridoxine (vitamin B6) is easily oxidized to pyridoxal by active manganese dioxide. Pulse polarograms recorded from alkaline media (pH 12–13) containing pyridoxal are very well-defined. The current is diffusion-controlled and the peak current is proportional to the concentration of pyriodoxine. This provides a simple determination of pyridoxine in multivitamin tablets. There is no interference from other vitamins; nicotinamide can be determined simultaneously from the same polarogram. The method is not applicable to tablets containing the coloids Methocel 4000 or Kollidon, which are strongly adsorbed on the electrode and inhibit the electroreduction of pyridoxal. 相似文献
735.
736.
Sigman MS Vachal P Jacobsen EN 《Angewandte Chemie (International ed. in English)》2000,39(7):1279-1281
737.
Insight into the controversial mechanism of the Mn - salen-catalyzed epoxidation of olefins is provided in a theoretical study based on density functional theory. The calculations suggest that radical species A, but not manganaoxetanes B, are likely candidates for viable intermediates. 相似文献
738.
Jacobsen JL 《Physical review letters》2008,100(11):118102
We present a Monte Carlo method that allows efficient and unbiased sampling of Hamiltonian walks on a cubic lattice. Such walks are self-avoiding and visit each lattice site exactly once. They are often used as simple models of globular proteins, upon adding suitable local interactions. Our algorithm can easily be equipped with such interactions, but we study here mainly the flexible homopolymer case where each conformation is generated with uniform probability. We argue that the algorithm is ergodic and has dynamical exponent z=0. We then use it to study polymers of size up to 64(3)=262 144 monomers. Results are presented for the effective interaction between end points, and the interaction with the boundaries of the system. 相似文献
739.
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 Ofte I 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 Pripstein M Roe NA 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 Cottingham WN Walker D 《Physical review letters》2008,100(5):051802
We measure the absolute branching fraction for D(0)-->K(-)pi(+) using partial reconstruction of B(0)-->D(*+)Xl(-)nu(l) decays, in which only the charged lepton and the pion from the decay D(*+)-->D(0)pi(+) are used. Based on a data sample of 230 x 10(6) BB pairs collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, we obtain B(D(0)-->K(-)pi(+)) = (4.007+/-0.037+/-0.072)%, where the first uncertainty is statistical and the second is systematic. 相似文献
740.
Aubert B Bona M Karyotakis Y Lees JP Poireau V Prencipe E Prudent X Tisserand V Garra Tico J Grauges E Lopez L Palano A Pappagallo M Eigen G Stugu B Sun L Abrams GS Battaglia M Brown DN Cahn RN Jacobsen RG Kerth LT Kolomensky YG Kukartsev G Lynch G Osipenkov IL Ronan MT Tackmann K Tanabe T Hawkes CM Soni N Watson AT Koch H Schroeder T Walker D Asgeirsson DJ Fulsom BG Hearty C Mattison TS McKenna JA Barrett M Khan A Teodorescu L Blinov VE Bukin AD Buzykaev AR Druzhinin VP Golubev VB Onuchin AP 《Physical review letters》2008,101(16):161801
With the full BABAR data sample of 465 x 10(6) B(over)B pairs, we observe the decays B+/- -->phiK_(1)(1270) +/- and B +/- -->phiK*_(2)(1430)+/-. We measure the branching fractions (6.1+/-1.6+/-1.1) x 10(-6) and (8.4+/-1.8+/-1.0) x 10(-6) and the fractions of longitudinal polarization 0.46 (+0.12+0.06) _(-0.13-0.07) and 0.80(+0.09)_(-0.10)+/-0.03, respectively. We also report on the B+/- -->phiK*_(0)(1430)+/- decay branching fraction of (7.0+/-1.3+/-0.9) x 10(-6) and several parameters sensitive to CP violation and interference in the above three decays. Upper limits are placed on the B+/- decay rates to final states with phi and K_1(1400)+/-, K*(1410)+/-, K2(1770)+/-, or K_2(1820)+/-. Understanding the observed polarization pattern requires amplitude contributions from an uncertain source. 相似文献