Reduction of Theoretical Uncertainty in Quantum Computing

A theoretical framework is developed to evaluatethe amount of intrinsic uncertainty, as distinguishedfrom operational uncertainty (noise), inherent inquantum computation. The temporal evolution of states in quantum computing is analyzeddiagramatically, providing a visual tool for therefining of quantum algorithms to help achieve minimaluncertainty and maximal efficiency, as well as forbetter understanding of the quantum entanglements crucial to quantumcomputing.     

Direct numerical simulation of wall turbulent flows with microbubbles

The marker‐density‐function (MDF) method has been developed to conduct direct numerical simulation (DNS) for bubbly flows. The method is applied to turbulent bubbly channel flows to elucidate the interaction between bubbles and wall turbulence. The simulation is designed to clarify the structure of the turbulent boundary layer containing microbubbles and the mechanism of frictional drag reduction. It is deduced from the numerical tests that the interaction between bubbles and wall turbulence depends on the Weber and Froude numbers. The reduction of the frictional resistance on the wall is attained and its mechanism is explained from the modulation of the three‐dimensional structure of the turbulent flow. Copyright © 2001 John Wiley & Sons, Ltd.     

Alternating Copolymerization of Ethylene and 5‐Hexen‐1‐ol with [Ethylene(1‐indenyl)(9‐fluorenyl)]‐zirconium Dichloride/Methylaluminoxane as the Catalyst

The copolymerization of ethylene and 5‐hexen‐1‐ol pretreated with trimethylaluminium was performed using [ethylene(1‐indenyl)(9‐fluorenyl)]zirconium dichloride/methylaluminoxane as the catalyst. The 5‐hexen‐1‐ol unit in the copolymer could be increased to about 50 mol‐% with increasing [5‐hexen‐1‐ol/ethylene[ ratio. ¹³C NMR analysis proved that the poly(ethylene‐co‐(5‐hexen‐1‐ol)) containing 50 mol‐% of 5‐hexen‐1‐ol units is an almost alternating copolymer.     

Designing an “A‐Ring‐with‐Branches” Polymer Topology by Electrostatic Self‐Assembly and Covalent Fixation with Interiorly Functionalized Telechelics Having Cyclic Ammonium Groups

A novel and unusual polymer topology, i.e. a‐ring‐with‐two‐branches, has been constructed efficiently by making use of an interiorly functionalized poly(tetrahydrofuran) (poly(THF)) having two pyrrolidinium groups. The dicarboxylate counterion, i. e. terephthalate, was then introduced by an ion‐exchange reaction of the interiorly located pyrrolidinium group. Subsequent heat treatment under appropriate dilution caused an efficient polymer cyclization to produce an a‐ring‐with‐two‐branches polymer topology in high yield through the selective and quantitative ring‐opening of the pyrrolidinium groups by the dicarboxylate counterion.     

Benzylic triflates prepared in‐situ: novel initiators for mono‐, bi‐ and trifunctional living poly(THF)s

Mono‐, bis‐, and tris(trifluoromethanesulfonate ester)s ((triflate ester)s) were prepared by the reaction of benzyl alcohol ( 1 ), 1,4‐bis(hydroxymethyl)benzene ( 2 ) and 1,3,5‐tris(hydroxymethyl)benzene ( 3 ) with trifluoromethanesulfonic anhydride in the presence of 2,6‐di‐tert‐butylpyridine. These benzylic triflate esters were applied in‐situ for the living polymerization of tetrahydrofuran (THF). The subsequent end‐capping reaction with a suitable nucleophile proceeded quantitatively to produce mono, bi‐ and, in particular, novel trifunctional telechelic poly(THF)s, respectively.     

In situ observation of protein-adsorbed stearic acid monolayer by Brewster angle microscopy and fluorescence microscopy

A fluorescence probe, fluorescein isothiocyanate (FITC), was introduced to proteins, and the morphology of protein-adsorbed stearic acid monolayer was observed by fluorescence microscopy and Brewster angle microscopy (BAM) in order to analyze images. At a low protein concentration, the surface pressure increased as shown by a sigmoidal curve. A number of stripe patterns in the BAM images increased and the shapes became clear with increasing concentration of proteins. Simultaneously, the size of circular islands also became small, and finally disappeared. These results suggest that the very large stripe patterns in the BAM image show the assembly of both proteins and stearic acid molecules, and small circular islands show only the stearic acid molecules. © 1998 John Wiley & Sons, Ltd.