Model discrimination using data collaboration

This paper introduces a practical data-driven method to discriminate among large-scale kinetic reaction models. The approach centers around a computable measure of model/data mismatch. We introduce two provably convergent algorithms that were developed to accommodate large ranges of uncertainty in the model parameters. The algorithms are demonstrated on a simple toy example and a methane combustion model with more than 100 uncertain parameters. They are subsequently used to discriminate between two models for a contemporarily studied biological signaling network.     

Direct measurement of quantum phase gradients in superfluid 4He flow

We report a new kind of experiment in which we generate a known superfluid velocity in a straight tube and directly determine the phase difference across the tube's ends using a superfluid matter wave interferometer. By so doing, we quantitatively verify the relation between the superfluid velocity and the phase gradient of the condensate macroscopic wave function. Within the systematic error of the measurement (approximately 10%) we find nu(s)=Planck's/m4InvertedDeltaphi.     

Power spectral analysis of a dynamical system

Power spectra for chaotic transitions in three dimensions are presented for a dynamical system first proposed by Rössler. Relations between the spectra and the topology of the corresponding strange attractor are discussed.     

无机物离子对CuS微晶形态结构的有效调控

以CuCl2·3H2O,Cu（CH3COO）2·H2O和CuSO4·5H2O作为铜源,并向反应体系中引入少量NaCl或NaNO3,通过乙二醇溶剂中的溶剂热反应,合成了形貌各异的CuS微晶．结合XRD和SEM表征,初步探讨了阴离子Cl-、CH3COO-、SO4^2-和阳离子Na’对CuS微晶生长过程的影响．结果表明,Na＋对CuS微晶的生长过程没有显著影响,而Cl、CH3COO-、SO4^2-由于在{1012}晶面上选择性吸附能力的差异,显著影响CuS微晶的形貌．本研究为进一步有效调控CuS微晶的形貌及性能奠定了基础．     

Beta-selective glycosylations with masked D-mycosamine precursors

[reaction: see text]. Both an intramolecular aglycon delivery (IAD) method and an intermolecular S(N)2 displacement method were examined for beta-selective glycosylations of cholesterol with D-mycosamine. An anomeric sulfoxide, sulfide, selenide, and fluoride were all successfully used as glycosyl donors in IAD reactions. The alpha-bromo ketone 19 was synthesized from protected mycosamine and employed in an intermolecular S(N)2 glycosylation reaction. Both routes were successful for the model alcohol, cholesterol.