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131.
Aubert B Bona M Karyotakis Y Lees JP Poireau V Prudent X Tisserand V Zghiche A Garra Tico J Grauges E Lopez L Palano A Pappagallo M Eigen G Stugu B Sun L Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Lynch G Osipenkov IL Ronan MT Tackmann K Tanabe T Wenzel WA del Amo Sanchez P Hawkes CM Soni N Watson AT Koch H Schroeder T Walker D Asgeirsson DJ Cuhadar-Donszelmann T Fulsom BG Hearty C Mattison TS McKenna JA Barrett M Khan A 《Physical review letters》2008,100(15):151802
We report a measurement of the branching fractions for _B-->D(*)(pi)l- _nu(l) decays based on 341.1 fb(-1) of data collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC PEP-II e+ e- storage rings. Events are tagged by fully reconstructing one of the B mesons in a hadronic decay mode. We obtain B(B- -->D(0)l-_nu(l)=(2.33+/-0.09(stat)+/-0.09(syst)%, B(B- -->D(*0)l-_nu(l)=(5.83+/-0.15(stat) +/-0.30(syst) %, B(_B(0)-->D+l-_nu(l)=(2.21+/-0.11(stat) +/-0.12(syst)%, B(_B(0)-->D(*)l-_nu(l)=(5.49+/-0.16(stat)+/-0.25(syst)%, B(B- -->D+pi-l-_nu(l)=(0.42+/-0.06(stat)+/-0.03(syst)%, B(B- -->D(*)+pi-l-_nu(l)=(0.59+/-0.05(stat)+/-0.04(syst)%, B(_B(0)-->D(0)pi+l-_nu(l)=(0.43+/-0.08(stat)+/-0.03(syst)%, and B(_B(0)-->D(*0)pi+l-_nu(l)=(0.48+/-0.08(stat)+/-0.04(syst)%. 相似文献
132.
Julien MH de Vaulx C Mayaffre H Berthier C Horvatić M Simonet V Wooldridge J Balakrishnan G Lees MR Chen DP Lin CT Lejay P 《Physical review letters》2008,100(9):096405
From 59Co and 23Na NMR, we demonstrate the impact of the Na+ vacancy ordering on the cobalt electronic states in Na0.75CoO2: at long time scales, there is neither a disproportionation into 75% Co3+ and 25% Co4+ states, nor a mixed-valence metal with a uniform Co3.25+ state. Instead, the system adopts an intermediate configuration in which 30% of the lattice sites form an ordered pattern of localized Co3+ states. Above 180 K, an anomalous mobility of specific Na+ sites is found to coexist with this electronic texture, suggesting that the formation of the latter may contribute to stabilizing the Na+ ordering. Control of the ion doping in these materials thus appears to be crucial for fine-tuning of their thermoelectric properties. 相似文献
133.
Eric F. Connor Inez Lees Derek Maclean 《Journal of polymer science. Part A, Polymer chemistry》2017,55(18):3146-3157
Polymer drugs are those in which a polymer agent has a direct therapeutic effect on the body. A major investigated area of polymer drugs is their use as binding agents, or sequestrants, which can neutralize or remove undesired components from the body. By taking advantage of the unique properties of crosslinked, insoluble polymers, new polymer drugs continue to be developed for oral use, acting in the gastrointestinal tract and excreted in the feces. Soluble polymer binders may be administered by a variety of routes and act at diverse sites of therapeutic action. This article reviews the properties of polymer drugs, particularly sequestrants, with an emphasis on recent advances in polymer properties which may enhance the utility of this class of drugs. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3146–3157 相似文献
134.
135.
In this work, the results of detailed spectroscopic analyses of the high-resolution Fourier transform infrared (IR) C-O stretch and far-infrared (FIR) torsion-rotation bands of methyl alcohol are applied to assign and predict FIR laser lines optically pumped by a CO2 laser in the dense Q-branch region of the C-O stretch band. The assignments are supported by means of closed combination loops of accurately measured transition frequencies. For the predicted FIR lines, the frequencies are deduced with an accuracy of ±0.001 cm−1, which is at least an order of magnitude better than can be obtained from direct wavelength measurements. The IR and FIR spectroscopic data relevant to the assignments are included. 相似文献
136.
K.D. Vernon-Parry L.T. Romano J.S. Lees C.R.M. Grovenor 《Physica C: Superconductivity and its Applications》1990,170(5-6):388-394
Degradation processes in 2212 thallium-based superconductors have been investigated using X-ray diffraction and electron microscopy techniques. It has been shown that the formation of amorphous or microcrystalline material by decomposition of the superconducting phase is followed by the crystallization of BaCo3 and other oxide compounds. The influence of preexisting BaCO3 on the rate of this degradation process has also been studied, and the results indicate that the removal of this stable precursor compound is an important step in improving the long term stability of the 2212 phase. 相似文献
137.
Oxygen-18 has been used as a tracer to study diffusion in the c-direction of rutile single crystals in the temperature range 1173–1473K. The distribution of the tracer was determined by means of a nuclear technique. The diffusion coefficient can be represented in this temperature range by the equation . A diffusion coefficient obtained at 1673 K using a different technique agrees well with the value obtained by extrapolation from the other results. Consideration of the results from specimens with different impurity concentrations leads to the conclusion that the diffusion which has been studied is extrinsic.The results obtained in this investigation are in good agreement with those of Haul and Dümbgen[l] and (by extrapolation) Gruenwald and Gordon [2] but not with those of Doskocil and Pospisil[3] and Bagshaw and Hyde[4]. 相似文献
138.
ALEPH Collaboration D. Buskulic D. Casper I. De Bonis D. Decamp P. Ghez C. Goy J. P. Lees M. N. Minard P. Odier et al. 《Zeitschrift fur Physik C Particles and Fields》1995,69(1):183-193
Using 22 pb−1 of data collected at LEP in 1992 on the peak of the Z resonance, the ALEPH collaboration has measured the polarisation of
the tau leptons decaying into
,πν, ρν and a1
ν from their individual decay product distributions. The measurement of the tau polarisation as a function of the production
polar angle yields the two parametersN
τ andN
e, where, in terms of the axial and vector couplingsg
Al andg
Vl,N
l=2g
Vl gAl/(g
Vl
2
+g
Al
2
). This analysis follows to a large extent the methods devised for the 1990 and 1991 data but with improvements which bring
a better understanding of the systematic uncertainties. Combining the 1992 measurements with our previously published results
yieldsN
τ=0.136±0.012±0.009 andN
e=0.129±0.016±0.005. Assuminge−τ universality, the measurements imply an effective weak mixing angle of sin
2
θ
W
eff
=0.2332±0.0014.
Deceased 相似文献
139.
The effects of dissolved electrolytes on the structure of liquid formamide have been investigated by Raman spectroscopy. The spectral features are dependent on the concentration and nature of the dissolved electrolyte and are discussed in terms of direct electrolyte formamide interactions. Two vN—H bands, arising from ion—formamide species, have been observed superimposed on the spectrum of residual liquid formamide. The results lend further support to the interaction model for electrolytes in liquid formamide previously proposed by us on the basis of nuclear magnetic resonance and infrared spectral data. 相似文献
140.
Two structurally simple and easily synthesized luminescent anion receptors featured with an amide-type anion binding site and rhenium(I) tricarbonyl pyridine signaling units have been developed, and they display outstanding sensitivity and selectivity toward a variety of anionic species. These complexes are highly emissive in solution. Upon anion binding, the emission intensity was significantly quenched. The sensitivities of these complexes are so high that the emission intensity can be effectively quenched by as much as 10% even in the presence of only 10(-8) M cyanide or fluoride anions. The ability of formation of intramolecular hydrogen bonding between the amide protons and central pyridine is believed to be responsible for the observed high selectivity. 相似文献