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71.
Aubert B Bona M Boutigny D Couderc F Karyotakis Y Lees JP Poireau V Tisserand V Zghiche A Grauges E Palano A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Charles E Gill MS Groysman Y Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Lynch G Mir LM Orimoto TJ Pripstein M Roe NA Ronan MT Wenzel WA del Amo Sanchez P Barrett M Ford KE Hart AJ Harrison TJ Hawkes CM Watson AT Held T Koch H Lewandowski B Pelizaeus M Peters K 《Physical review letters》2006,97(23):232001
We report the first observation of an excited singly charmed baryon Omega c* (css) in the radiative decay Omega c0gamma, where the Omega c0 baryon is reconstructed in the decays to the final states Omega(-)pi+, Omega(-)pi+pi0, Omega(-)pi+pi(-)pi+, and Xi(-)K(-)pi+pi+. This analysis is performed using a data set of 230.7 fb(-1) collected by the BABAR detector at the PEP-II asymmetric-energy B factory at the Stanford Linear Accelerator Center. The mass difference between the Omega c* and the Omega c0 baryons is measured to be 70.8+/-1.0(stat)+/-1.1(syst) MeV/c2. We also measure the ratio of inclusive production cross sections of Omega c* and Omega c0 in e+e(-) annihilation. 相似文献
72.
Quantum error-correcting codes can protect multipartite quantum states from errors on some limited number of their subsystems (usually qubits). We construct a family of Bell inequalities which inherit this property from the underlying code and exhibit the violation of local realism, without any quantum information processing (except for the creation of an entangled state). This family shows no reduction in the size of the violation of local realism for arbitrary errors on a limited number of qubits. Our minimal construction requires preparing an 11-qubit entangled state. 相似文献
73.
Emily K. Corlett Helen Blade Leslie P. Hughes Philip J. Sidebottom David Walker Richard I. Walton Steven P. Brown 《Magnetic resonance in chemistry : MRC》2020,58(11):1026-1035
Single-crystal X-ray diffraction structures of the 5-amino-2-methylpyridinium hydrogen fumarate salt have been solved at 150 and 300 K (CCDC 1952142 and 1952143). A base–acid–base–acid ring is formed through pyridinium-carboxylate and amine-carboxylate hydrogen bonds that hold together chains formed from hydrogen-bonded hydrogen fumarate ions. 1H and 13C chemical shifts as well as 14N shifts that additionally depend on the quadrupolar interaction are determined by experimental magic angle spinning (MAS) solid-state nuclear magnetic resonance (NMR) and gauge-including projector-augmented wave (GIPAW) calculation. Two-dimensional homonuclear 1H-1H double-quantum (DQ) MAS and heteronuclear 1H-13C and 14N-1H spectra are presented. Only small differences of up to 0.1 and 0.6 ppm for 1H and 13C are observed between GIPAW calculations starting with the two structures solved at 150 and 300 K (after geometry optimisation of atomic positions, but not unit cell parameters). A comparison of GIPAW-calculated 1H chemical shifts for isolated molecules and the full crystal structures is indicative of hydrogen bonding strength. 相似文献
74.
A preliminary LEED theory experiment comparison for the InP(110) surface has been performed using experimental I(V) data recorded in the authors' laboratory from a clean, UHV-cleaved, single crystal specimen. A range of model surface geometries including both lateral and vertical displacements of the top layer In and P atoms have been examined. The results clearly demonstrate that the structure of this surface is substantially different from a simple termination of the bulk lattice and that the disturbance extends more than one layer into the real crystal. The possibility of extending the analysis to include second layer distortions is considered. 相似文献
75.
W.W. Walker 《Physics letters. A》1980,77(6):466-468
The lifetimes of positrons annihilating in cholesterol and in cholesteryl oleate have been measured as a function of temperature in the vicinity of a previously reported solid-solid transition in each compound. The observed changes in lifetime parameters are discussed in terms of structural changes occurring in these two compounds. 相似文献
76.
Bulk Poly(N-isopropylacrylamide) (PNIPAm) hydrogels are thermally responsive polymers that undergo a sharp volumetric phase transition around its lower critical solution temperature of 33 °C. The physical characteristics of bulk, micro-, and nano-form PNIPAm hydrogel have been well-studied, and have applications ranging from biomedical devices to mechanical actuators. An important physical characteristics which reveals lack of available information is speed of sound. Prior studies have utilized Brillouin scattering, multi-echo reflection ultrasound spectroscopy, the sing-around method, and others in measuring the speed of sound. We use a planar resonant cavity with bulk PNIPAm hydrogel in aqueous solution to determine the temperature dependent speed of sound around the lower critical solution temperature. The results show sharp nonmonotonic behavior of the sound velocity in vicinity of the phase transition. 相似文献
77.
M. Leins J. Kopecki S. Gaiser A. Schulz M. Walker U. Schumacher U. Stroth T. Hirth 《等离子体物理论文集》2014,54(1):14-26
Microwave plasmas at atmospheric pressure are used for surface treatments like for example cleaning, sterilization or decontamination purposes, for a pre‐treatment to increase the adhesion of lacquer, paint, or glue, and for the deposition of different kind of layers and coatings. Micro plasma jets can also be applied for biomedical applications and for treatment of small and complex geometries like for example the inside of capillaries. Larger plasma torches which exhibit higher gas temperatures can also be used for chemical syntheses like waste gas decomposition, methane pyrolysis, or carbon dioxide dissociation and for plasma spraying purposes. In the present publication an overview on the development and the investigation of the operating principle of two atmospheric pressure microwave plasma torches at frequencies of 2.45 GHz and 915 MHz will be presented. The plasma sources are based on a cylindrical resonator combined with coaxial structures. To explain how these plasma sources work, simulations of the electric field distribution will be discussed. Furthermore, some physical characteristics of an air and an Ar/H2 atmospheric plasma like gas temperatures, excitation temperatures and densities as well as the heating of the plasma by the microwave will be investigated. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
78.
F. Christopher Bi Gary E. Aspnes Angel Guzman-Perez Daniel P. Walker 《Tetrahedron letters》2008,49(11):1832-1835
In this Letter, we report a novel approach to the preparation of 3-anilino-pyrazin-2(1H)-ones and 3-anilino-quinoxalin-2(1H)-ones from the corresponding 3-halo pyrazin-2-amines and 3-haloquinoxalin-2-amines, using a microwave-mediated Smiles rearrangement. 相似文献
79.
Evans DR Macniven RP Labanca M Walker J Notarnicola SM 《Journal of chromatography. A》2008,1177(2):265-271
An hydrophobic interaction chromatography step was developed for the large-scale production of an Fc-fusion biologic. Two abundant product-related impurities were separated from the active monomer using a Butyl resin and a simple step-wash and step-elution strategy. Capacity and resolution of the HIC step was optimal when sodium sulfate was employed as the lyotropic salt and pore size of the Butyl resin was 750A. Factorial analysis identified critical parameters for the Butyl chromatography and an operating window capable of delivering high product quality and yield over a broad column loading range. 相似文献
80.
Taek-Hyoun Chang Edward B. Walker Pill-Soon Song 《Photochemistry and photobiology》1981,33(6):933-936
Abstract— Two simple methods of phototaxis measurements have been applied to study the effects of ionophores on the negative phototactic response in Stentor coeruleus. The inhibitory effects of Ca2+ -ionophore (A23187), Ca2+ -blocking agent (Ruthenium Red), and K+ -ionophore (valinomycin) on photo-taxis have been determined. Results suggest that the influx of Ca2+ plays a transducing role in the phototaxis of Stentor. 相似文献