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431.
Aggarwal MM Ahammed Z Alakhverdyants AV Alekseev I Alford J Anderson BD Anson D Arkhipkin D Averichev GS Balewski J Barnby LS Baumgart S Beavis DR Bellwied R Betancourt MJ Betts RR Bhasin A Bhati AK Bichsel H Bielcik J Bielcikova J Biritz B Bland LC Bonner BE Bouchet J Braidot E Brandin AV Bridgeman A Bruna E Bueltmann S Bunzarov I Burton TP Cai XZ Caines H Calderón de la Barca Sánchez M Catu O Cebra D Cendejas R Cervantes MC Chajecki Z Chaloupka P Chattopadhyay S Chen HF Chen JH Chen JY 《Physical review letters》2010,105(20):202301
The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200 GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5 GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT. 相似文献
432.
433.
Background
The involvement of astrocyte water channel aquaporin-4 (AQP4) in autoimmune diseases of the central nervous system has been suggested following the identification of AQP4 autoantibodies in neuromyelitis optica, an inflammatory demyelinating disease. 相似文献434.
Maotong Xu Andrew R. Jupp Maegan S. E. Ong Katherine I. Burton Saurabh S. Chitnis Douglas W. Stephan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(17):5763-5767
A series of thirty‐three N,N′‐diaryl, dialkyl, and alkyl‐aryl ureas have been prepared in pyridine or toluene by reaction of silylamines with CO2. This protocol is shown to provide facile access to 13C‐labeled ureas, as well as chiral and macrocyclic ureas. These reactions proceed through initial generation of the corresponding silylcarbamates, which subsequently react with silylamine under thermal conditions to afford the thermodynamically favored urea and disilyl ether. 相似文献
435.
We perform ab initio calculations of the electronic structure and conductance of atomic-size Ni nanowires with domain walls only a few atomic lattice constants wide. We show that the hybridization between noncollinear spin states leads to a reduction of the magnetic moments in the domain wall resulting in the enhancement of the domain wall resistance. Experimental studies of the magnetic moment softening may be feasible with modern techniques such as scanning tunneling spectroscopy. 相似文献
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Robin S. McDowell Martin J. Reisfeld Harold W. Galbraith Burton J. Krohn Herbert Flicker R.Craig Kennedy Jack P. Aldridge Norris G. Nereson 《Journal of Molecular Spectroscopy》1980,83(2):440-450
The 16-μm bending fundamentals (ν4) of 12CF4, 13CF4, and 14CF4 have been observed at Doppler-limited resolution using a tunable PbSnSe semiconductor diode laser. The tetrahedral splittings of the rotational manifolds have been observed in all three branches, and in particular the dense and partially overlapping transitions in the Q branches have been resolved and assigned. A least-squares fit of the Hamiltonian, including off-diagonal terms, yielded five scalar and three tensor spectroscopic constants for each of the three isotopes. From these constants the upper-state rotational constant B4 and the Coriolis constant ζ4 have been calculated, together with some of the other molecular constants. An absorption feature at about 0.18 cm?1 to the red of the main Q branch of each isotopic species has been identified as the Q branch of (ν2 + ν4) ? ν2, which is the transition that lases when CF4 is pumped by a CO2 laser at 9.4 μm (i.e., in ν2 + ν4). 相似文献
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440.
The breakup of a drop of inviscid fluid into two smaller drops is determined by a competition between surface and inertial forces. This process forms a thin filament of fluid with a connecting neck that shrinks to zero diameter at a finite time singularity. We present measurements of the electrical resistance of a liquid bridge of mercury as it undergoes pinch off. The electrical measurements allow us to probe the region of the singularity down to nanosecond times and nanometer lengths. Near pinch off, the resistance of the liquid bridge diverges as t(-2/3), as expected for inviscid flow. 相似文献