Tetraphenylboroxinate(1-) salts of monoborate cations: Synthesis and single-crystal X-ray structures of [Ph2B{OCH2CH2N(Me)(CH2)n}2][Ph4B3O3] (n = 4, 5)

The salts, [Ph₂B{OCH₂CH₂N(Me)(CH₂)_n}₂][Ph₄B₃O₃] (n = 4, 5), were prepared in moderate yields in MeOH solution from reaction of Ph₂BOBPh₂ with [N(CH₂)_n(Me)(CH₂CH₂OH)][OH] and PhB(OH)₂ in a 1:2:4 ratio. The reactions also lead to Ph₃B₃O₃. Both salts were characterized by NMR (¹H, ¹³C, ¹¹B) IR, and single-crystal XRD studies. The salts are comprised of cationic monoborates (zwitterionic, 2N⁺ and 1B⁻) and tetraphenylboroxinate anions.     

Cold nuclear matter effects on J/ψ yields as a function of rapidity and nuclear geometry in d+A collisions at sqrt[s(NN)]=200 GeV

We present measurements of J/ψ yields in d+Au collisions at sqrt[s(NN)]=200 GeV recorded by the PHENIX experiment and compare them with yields in p+p collisions at the same energy per nucleon-nucleon collision. The measurements cover a large kinematic range in J/ψ rapidity (-2.2相似文献   

Controlled coupling of a single nitrogen-vacancy center to a silver nanowire

We report on the controlled coupling of a single nitrogen-vacancy (NV) center to a surface plasmon mode propagating along a chemically grown silver nanowire (NW). We locate and optically characterize a single NV center in a uniform dielectric environment before we controllably position this emitter in the close proximity of the NW. We are thus able to control the coupling of this particular emitter to the NW and directly compare the photon emission properties before and after the coupling. The excitation of single plasmonic modes is witnessed and a total rate enhancement by a factor of up to 4.6 is demonstrated.     

Modification of the 3He phase diagram by anisotropic disorder

Motivated by the recent prediction that uniaxially compressed aerogel can stabilize the anisotropic A phase over the isotropic B phase, we measure the pressure dependent superfluid fraction of (3)He entrained in 10% axially compressed, 98% porous aerogel. We observe that a broad region of the temperature-pressure phase diagram is occupied by the metastable A phase. The reappearance of the A phase on warming from the B phase, before superfluidity is extinguished at T(c), is in contrast to its absence in uncompressed aerogel. The phase diagram is modified from that of pure (3)He, with the disappearance of the polycritical point (PCP) and the appearance of a region of A phase extending below the PCP of bulk (3)He, even in zero applied magnetic field. The expected alignment of the A phase texture by compression is not observed.     

Polycatenar, bent-core pyridines and their discotic complexes with silver(I)

New, bent-core, polycatenar pyridine mesogens are described. Binding to silver(I) leads to complexes properly described as discotic.     

Stability of the Cournot process – experimental evidence

We report results of experiments designed to test the predictions of the best-reply process. In a Cournot oligopoly with four firms, the best-reply process should theoretically explode if demand and cost functions are linear. We find, however, no experimental evidence of such instability. Moreover, we find no differences between a market which theoretically should not converge to Nash equilibrium and one which should converge because of inertia. We investigate the power of several learning dynamics to explain this unpredicted stability. Received May 1997/Revised June 2002     

Modelling the effects of emergent vegetation on an open‐channel flow using a lattice model

A two‐dimensional lattice model has been developed to describe the influence of vegetation on the turbulent flow structure in an open channel. The model includes the influence of vegetation density on the frictional effect of the channel bed and walls. For the walls, a semi‐slip boundary condition has been considered as an alternative to overcome the no‐slip boundary condition limitations in turbulent flows. The drag stress exerted by the flow on the vegetation as well as the gravity effect has also been taken into account. The proposed lattice model has been used to simulate the experimental results reported from the study of the influence of alternate vegetated zones on the open‐channel flow. The results show that the lattice model approach is a valid tool for describing these kinds of flows. Copyright © 2007 John Wiley & Sons, Ltd.     

Children's Books Reviewed

Maps and Globes Jack Knowlton Hurricane Watch Franklyn M. Branley Sunshine Makes the Seasons Franklyn M. Branley Heart Disease America's No. 1 Killer Dr. Alvin and Virginia B. Silverstein Cuts, Breaks, Bruises and Burns Joanna Cole Auks, Rocks, and the Odd Dinosaur Inside Stories from the Smithsonian Institute by Peggy Thomson The Secret Life of Cosmetics: A Science Experiment Book Vicki Cobb A Children's Zoo Tana Hoban Milk Donald Carrick Wallaby Creek Joyce Powzyk Being a Twin, Having a Twin Maxine Rosenberg