Positive muon sites and possibility of anyons in the YBa2Cu3O x system

Possible positive muon sites in YBa₂Cu₃O _x were determined from the observedμ ⁺ hyperfine fields in antiferromagnetically ordered YBa₂Cu₃O _x and GdBa₂Cu₃O₇. After determining theμ ⁺ sites, the possibility of anyons or chiral spin ordering in the superconducting YBa₂Cu₃O₇ is discussed. Positive muon implanted in YBa₂Cu₃O₇ feel static magnetic fields of average 1.4G, which are explicable in terms of nuclear magnetic dipolar fields. Non observation of static local magnetic fields of electronic origin (the upper limit is the order of 0.1 G) means that anyons or chiral spin ordering might not exist in superconducting YBa₂Cu₃O₇.     

Numerical analysis of a discrete-time finite capacity queue with a burst arrival

We study a discrete-time, multi-server, finite capacity queue with a burst arrival. Once the first job of a burst arrives at the queue, the successive jobs will arrive every time slot until the last job of the burst arrives. The number of jobs and the inter-arrival time of bursts are assumed to be generally distributed, and the service time is assumed to be equal to one slot. We propose an efficient numerical method to exactly obtain the job loss probability, the waiting time distribution and the mean queue length using an embedded Markov chain at the arrival instants of bursts.     

Amperometric response to reducing carbohydrates of an enzyme electrode based on oligosaccharide dehydrogenase. Detection of lactose and α-amylase

A mediated amperometric enzyme electrode, which was constructed by immobilizing oligosacharide dehydrogenase behind a dialysis membrane on the surface of a carbon paste electrode containing p-benzoquinone, showed a current response to d-xylose, d-galactose, d-mannose, lactose, maltose, maltotriose, maltopentaose and maltohexaose. The sensitivity of the current response to these carbohydrates was dependent on the kinetics of the immobilized enzyme reaction and/or the permeation rate of the substrate through the dialysis membrane. Hence the sensitivity could be varied by controlling the amount of the immobilized enzyme and the thickness of the dialysis membrane. The time dependence of the current response ofthe enzyme electrode with a large amount of the immobilized enzyme and a thicker dialysis membrane could be explained by an equation describing diffusion of the substrate in the membrane. The enzyme electrode was used to measure lactose in milk and to assay α-amylase in standard serum.     

Reaction of (dialkylaminomethyl)trimethylsilanes with benzyne

Reactions of (dialkylaminomethyl)trimethylsilanes [dimethylamino-, diethylamino-, pyrrolidino- and morpholino-] with benzyne in THF gave two types of aniline derivatives: N-alkyl-N-(1-trimethylsilylalkyl)anilines and N-alkyl-N-trimethylsilylmethylanilines. From (piperidinomethyl)trimethylsilane, however, unexpected 1-(α-trimethylsilylbenzyl)piperidine was obtained together with N-(4-pentenyl)-N-trimethylsilylmethylaniline.     

Continuous synthesis of CdSe-ZnS composite nanoparticles in a microfluidic reactor

ZnS-coated CdSe composite particles have been continuously synthesized in a microfluidic reactor. By using this system, CdSe particles and a ZnS coating can be produced in sequence, and the particle size and layer thickness can be directly adjusted by the residence time. It demonstrated that the continuous synthesis in the microreactor was a simple and efficient way to prepare composite particles with different structures and determine the optimized experimental conditions.     

Micro-particle sorting by Newton-ring device

A Newton-ring micro-particle sorter was constructed from a small convex lens and a flat glass. The sub-micrometer gap between them was controlled by a piezo-actuator and utilized for the fractionation of very small amounts of micro-particles in liquid.     

Synthesis and antifungal activity of novel 14-membered benzomacrolides, as galbonolide analogues

Asymmetric total synthesis of benzene analogues of galbonolide, a 14-membered antifungal macrolide, possessing a benzene ring instead of a conjugated diene structure, was achieved starting from chiral 1-aryl-1-propanol obtained by enzyme-catalyzed kinetic resolution with high enantioselectivity. Representatively, a method for the introduction of a methylthio and chloride function at the vinyl position was also established. The resulting analogues unfortunately exhibited very little antifungal potency in comparison with galbonolide A.