Precision measurements of the lambda(+)(c) and D0 lifetimes

We report new precision measurements of the lifetimes of the Lambda(+)(c) and D0 from SELEX, the charm hadroproduction experiment at Fermilab. Based upon 1630 Lambda(+)(c) and 10 210 D0 decays we observe lifetimes of tau[Lambda(+)(c)] = 198.1+/-7.0+/-5.6 fs and tau[D0] = 407.9+/-6.0+/-4.3 fs.     

LC-APCI-MS-MS methodology for determination of glybenclamide in human plasma

A liquid chromatographic/atmospheric pressure chemical ionization tandem mass spectrometric method (LC-APCI-MS-MS) for the determination of glybenclamide in human plasma is described. Glypizide, an analogue of glybenclamide, was used as internal standard. The analyte was extracted from plasma with diethyl ether/dichloromethane (70:30 v/v). The chromatography uses C₁₈ and 0.01 mol L^–1 acetic acid/acetonitrile (20:80 v/v) as stationary and mobile phase, respectively. Quantitation was preformed by using multiple reaction monitoring (MRM) of the precursor ion (m/z 494.2368.8) and the related product ion (m/z 446.0347.3) using the internal standard method. The analytical curve was linear in the range 1–300 ng mL^–1, and for a 400-L sample of human plasma, the limit of determination of the method was 1 ng mL^–1. The coefficients of variation of the method for intra-assay (within-run precision) and inter-assay (between-run precision) were less than 10%. The method was shown to be suitable for pharmacokinetic studies.An erratum to this article can be found at     

The influence of the entrance channel dynamics on the evaporation residue formation

The dynamical effects of the entrance channel on the competition between quasifission and fusion processes, and on the evaporation residue formation are investigated. We have analyzed the results and compared our calculations with the experimental data obtained in the ¹⁶ O + ²⁰⁴ Pb and ⁹⁶ Zr + ¹²⁴ Sn reactions having very different mass asymmetries and leading to the ²²⁰ Th ^* compound nucleus. We have found that different partial capture cross-sections for these reactions lead to different fusion-quasifission competitions and, consequently, to different partial fusion cross-sections of the compound nucleus formed in the two reactions. The dynamical conditions also affect the fission-evaporation competition of the excited intermediate nuclei along the CN de-excitation cascade and, consequently, the evaporation residue formation.Received: 8 March 2004, Revised: 5 April 2004, Published online: 25 October 2004PACS: 25.70.Jj Fusion and fusion-fission reactions - 25.70.-z Low and intermediate energy heavy-ion reactions - 27.80. + w - 27.90. + b      

The Steady State Fluctuation Relation for the Dissipation Function

We give a proof of transient fluctuation relations for the entropy production (dissipation function) in nonequilibrium systems, which is valid for most time reversible dynamics. We then consider the conditions under which a transient fluctuation relation yields a steady state fluctuation relation for driven nonequilibrium systems whose transients relax, producing a unique nonequilibrium steady state. Although the necessary and sufficient conditions for the production of a unique nonequilibrium steady state are unknown, if such a steady state exists, the generation of the steady state fluctuation relation from the transient relation is shown to be very general. It is essentially a consequence of time reversibility and of a form of decay of correlations in the dissipation, which is needed also for, e.g., the existence of transport coefficients. Because of this generality the resulting steady state fluctuation relation has the same degree of robustness as do equilibrium thermodynamic equalities. The steady state fluctuation relation for the dissipation stands in contrast with the one for the phase space compression factor, whose convergence is problematic, for systems close to equilibrium. We examine some model dynamics that have been considered previously, and show how they are described in the context of this work.     

Electro-initiated cationic polymerizations—VII: The use of perchlorates and of complex anions containing salts for the electropolymerization of oxyheterocyclic compounds

Electropolymerizations of some oxyheterocyclic monomers have been carried out under amperostatic conditions at Pt electrodes in both 1,2-dichloroethane and acetonitrile solution with various electrolytes. The experiments in 1,2-dichloroethane confirmed results previously obtained for vinylic compounds. The results in acetonitrile in the presence of perchlorates needed an investigation of the electrolysis in the absence of monomer. Both amperostatic and potentiostatic electrolyses showed that the acidity responsible for the polymerization is only one of the various products formed by the reaction between anodically produced chlorine dioxide and the solvent, so that the polymerization cannot be controlled. Cyclic voltammetries carried out on various lactones and on oxirane showed the impossibility of performing direct electropolymerization via anodic monomer oxidation. Hence, some reported electropolymerizations of such monomers under similar conditions must be attributed to the mixture of acids formed by secondary reactions in the anolyte.     

Boundedness of solutions of linear differential systems with periodic coefficients

Archive for Rational Mechanics and Analysis -     

Pseudopotentials for non-linear evolution equations in 2 + 1 dimensions

In this paper the concept of pseudopotential is generalized to non-linear evolution equations in 2 + 1 dimensions. If the equations satisfied by the pseudopotential are of a Riccati-type in the x-variable, it is shown how to obtain both the generalized AKNS system and the auto-Bäcklund transformation for the corresponding non-linear evolution equation. Several examples are given: Kadomtsev-Petviashvili, modified Kadomtsev-Petviashvili, (2 + 1 dim.)-Harry-Dym, and (2 + 1 dim.)-Sawada-Kotera equations.