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151.
Burke LA Gonella G Heirtzler F Dai HL Jones S Zubieta J Roche AJ 《Chemical communications (Cambridge, England)》2012,48(7):1000-1002
The dimeric self-assembly program of a new, multidentate ligand with cuprous ions overcomes crystal packing forces, which leads to C(i) symmetry in the solid state, to form a no less than partially C(2)-symmetric structure in solution. The resulting tetranitro-substituted dicopper(i) metallocyclophane displays an exceptionally strong second harmonic frequency response (β = (3000 ± 600) × 10(-30) esu for a fundamental at 800 nm). 相似文献
152.
153.
154.
McManamon C Burke AM Holmes JD Morris MA 《Journal of colloid and interface science》2012,369(1):330-337
This study examines the synthesis of SBA-15 with tailored pore sizes through controlled thermal treatment for the adsorption of Pb and Cd ions. The aim is to produce a material that can adsorb heavy metals at both high and low concentrations. The materials were characterised by means of N(2) physisorption, powder X-ray diffraction (PXRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), microanalysis and transmission electron microscopy (TEM). The surface areas ranged from 410 to 871 m(2)g(-1), and pore diameter was increased from 5.9 to 10.8 nm. This method allows for maximum adsorption of metal ions at very low concentrations. Metal ion adsorption was determined using an Atomic Absorption Spectrophotometer. The effects of pH were found to play a major role in the precipitation and, therefore, adsorption of metal ions. This method proved to be efficient at adsorbing large quantities of both metals (39 and 41 mg g(-1) for Pb and Cd, respectively). 相似文献
155.
Both enantiomers of Garner's aldehyde (3) are prepared from the same alkene 4 by catalytic asymmetric hydroformylation. 相似文献
156.
D'Sa RA Raj J McMahon MA McDowell DA Burke GA Meenan BJ 《Journal of colloid and interface science》2012,375(1):193-202
This study investigates the role that surface functionalisation of silicone elastomer (SE) by atmospheric pressure plasma induced graft immobilisation of poly(ethylene glycol) methyl ether methacrylate (PEGMA) plays in the attendant biological response. SE is used in modern ophthalmic medical devices and samples of the material were initially plasma treated using a dielectric barrier discharge reactor (DBD) to introduce reactive oxygen functionalities, prior to in situ grafting of two molecular weights of PEGMA (MW 1000 Da: PEGMA(1000), MW 2000 Da: PEGMA(2000)). The variously processed surfaces were characterised by water contact angle analysis, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry and atomic force microscopy. Lens epithelial cells were then cultured on the PEGMA grafted SE surfaces. It was found that cells on the pristine surface were not well spread and had shrunken morphology. On the DBD pre-treated surfaces, the cells were well spread. On the PEGMA(1000) surface, the cells displayed evidence of shrinkage and were on the verge of detaching. Remarkably, on the PEGMA(2000) surface, no cell adhesion was detection. Bacterial adhesion to the surfaces was studied using Staphylococcus aureus NTC8325. There was no difference in the number of bacteria adhering to any of the surfaces studied. 相似文献
157.
In the last few years, a significant number of multi-objective metaheuristics have been proposed in the literature in order
to address real-world problems. Local search methods play a major role in many of these metaheuristic procedures. In this
paper, we adapt a recent and popular indicator-based selection method proposed by Zitzler and Künzli in 2004, in order to
define a population-based multi-objective local search. The proposed algorithm is designed in order to be easily adaptable,
parameter independent and to have a high convergence rate. In order to evaluate the capacity of our algorithm to reach these
goals, a large part of the paper is dedicated to experiments. Three combinatorial optimisation problems are tested: a flow
shop problem, a ring star problem and a nurse scheduling problem. The experiments show that our algorithm can be applied with
success to different types of multi-objective optimisation problems and that it outperforms some classical metaheuristics.
Furthermore, the parameter sensitivity analysis enables us to provide some useful guidelines about how to set the parameters. 相似文献
158.
159.
J. V. Burke A. S. Lewis M. L. Overton 《Proceedings of the American Mathematical Society》2001,129(6):1635-1642
Given an affine subspace of square matrices, we consider the problem of minimizing the spectral abscissa (the largest real part of an eigenvalue). We give an example whose optimal solution has Jordan form consisting of a single Jordan block, and we show, using nonlipschitz variational analysis, that this behaviour persists under arbitrary small perturbations to the example. Thus although matrices with nontrivial Jordan structure are rare in the space of all matrices, they appear naturally in spectral abscissa minimization.
160.
Anthony J. Burke Helmut W. Schmalle Bernard A. Brady W. Ivo O'Sullivan 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):484-486
The title compound, C17H14O4, is an unprecedented new synthetic isoaurone‐type enol ether that has the E configuration. The planar furanone ring is fused to a methoxybenzene ring system, with an interplanar angle of 175.7 (1)°. Due to this ring fusion, the six‐membered ring has a significant amount of ring strain, as shown by the internal ring angle range of 115.8 (1)–124.7 (1)°, whereas the vinylic phenyl ring has internal angles between 119.7 (1) and 120.2 (1)°. The molecules form infinite hydrogen‐bonding layers along the b direction of the form C—H?O, where the keto O atom acts as a bifurcated acceptor. These layers are connected along the c direction by another hydrogen bond with a methoxy H atom as donor. In addition to this connection, the layers are stacked via centres of symmetry by a pair of symmetry‐related benzofuranone ring systems. 相似文献