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71.
Russell Golman 《International Journal of Game Theory》2011,40(4):719-733
In this paper, we investigate the aggregate behavior of populations of learning agents. We compare the outcomes in homogenous
populations learning in accordance with imitate the best dynamics and with replicator dynamics to outcomes in populations
that mix these two learning rules. New outcomes can emerge. In certain games, a linear combination of the two rules almost
always attains an equilibrium that homogenous learners almost never locate. Moreover, even when almost all weight is placed
on one learning rule, the outcome can differ from homogenous use of that rule. Thus, allowing even an arbitrarily small chance
of using an alternative learning style can shift a population to select a different equilibrium. 相似文献
72.
Comparative Studies of Thermally Induced Homolytic CarbonCarbon Bond Cleavage Reactions of Strained Dicarba[2]ferrocenophanes and Their Ring‐Opened Oligomers and Polymers 下载免费PDF全文
Andrew D. Russell Prof. Joe B. Gilroy Prof. Ian Manners 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(14):4077-4085
Reactivity studies of dicarba[2]ferrocenophanes and also their corresponding ring‐opened oligomers and polymers have been conducted in order to provide mechanistic insight into the processes that occur under the conditions of their thermal ring‐opening polymerisation (ROP) (300 °C). Thermolysis of dicarba[2]ferrocenophane rac‐[Fe(η5‐C5H4)2(CHPh)2] (rac‐ 14 ; 300 °C, 1 h) does not lead to thermal ROP. To investigate this system further, rac‐ 14 was heated in the presence of an excess of cyclopentadienyl anion, to mimic the postulated propagating sites for thermally polymerisable analogues. This afforded acyclic [(η5‐C5H5)Fe(η5‐C5H4)‐CH2Ph] ( 17 ) through cleavage of both a Fe?Cp bond and also the C?C bond derived from the dicarba bridge. Evidence supporting a potential homolytic C?C bond cleavage pathway that occurs in the absence of ring‐strain was provided through thermolysis of an acyclic analogue of rac‐ 14 , namely [(η5‐C5H5)Fe(η5‐C5H4)(CHPh)2‐C5H5] ( 15 ; 300 °C, 1 h), which also afforded ferrocene derivative 17 . This reactivity pathway appears general for post‐ROP species bearing phenyl substituents on adjacent carbons, and consequently was also observed during the thermolysis of linear polyferrocenylethylene [Fe(η5‐C5H4)2(CHPh)2]n ( 16 ; 300 °C, 1 h), which was prepared by photocontrolled ROP of rac‐ 14 at 5 °C. This afforded ferrocene derivative [Fe(η5‐C5H4CH2Ph)2] ( 23 ) through selective cleavage of the ?H(Ph)C?C(Ph)H? bonds in the dicarba linkers. These processes appear to be facilitated by the presence of bulky, radical‐stabilising phenyl substituents on each carbon of the linker, as demonstrated through the contrasting thermal properties of unsubstituted linear trimer [(η5‐C5H5)Fe(η5‐C5H4)(CH2)2(η5‐C5H4)Fe(η5‐C5H4)(CH2)2(η5‐C5H4)Fe(η5‐C5H5)] ( 29 ) with a ?H2C?CH2? spacer, which proved significantly more stable under analogous conditions. Evidence for the radical intermediates formed through C?C bond cleavage was detected through high‐resolution mass spectrometric analysis of co‐thermolysis reactions involving rac‐ 14 and 15 (300 °C, 1 h), which indicated the presence of higher molecular weight species, postulated to be formed through cross‐coupling of these intermediates. 相似文献
73.
Daniele Giallombardo Adam C. Nevin William Lewis Christopher C. Nawrat Russell R.A. Kitson Christopher J. Moody 《Tetrahedron》2014
A synthesis of the naturally occurring xanthone toxyloxanthone B is described, in which the key step is the regioselective addition of a methyl salicylate to a substituted benzyne, followed by cyclization of the intermediate aryl anion to form the xanthone, the regiochemistry of the aryne addition being confirmed by X-ray crystallography. Subsequent introduction of the pyran ring by [3,3]-rearrangement and deprotection completed the synthesis. 相似文献
74.
75.
Wetting behavior of a polymer resin used as matrix on fabric surfaces is one of the key attributes for making high quality
structural composites. Though incorporation of various functionalized nanoparticles can stimulate improvements to many properties
of epoxy resins, there has not been any report on wettability of any nano-modified epoxy on rough inclined fabric surfaces.
In this research work, wetting behavior of a previously developed nano-epoxy resin modified by a type of reactive graphitic
nanofibers (r-GNFs) was investigated. The observation results revealed that a unique wetting behavior was discovered from
the nano-epoxy on rough fabric surfaces due to the contribution of the r-GNFs. Based on this dramatically improved wettability
of the epoxy, a concept of dry–wet contact model was proposed to interpret the different wetting phenomenon observed from
the nano-epoxy and that of the pure epoxy. The improved wetting characteristics of the nano-epoxy system will be essential
for enabling future energy efficient infusion processing for manufacturing high quality and high-performance structural composite
applications. 相似文献
76.
The general topic of this review is protein‐based underwater adhesives produced by aquatic organisms. The focus is on mechanisms of interfacial adhesion to native surfaces and controlled underwater solidification of natural water‐borne adhesives. Four genera that exemplify the broad range of function, general mechanistic features, and unique adaptations are discussed in detail: blue mussels, acorn barnacles, sandcastle worms, and freshwater caddisfly larva. Aquatic surfaces in nature are charged and in equilibrium with their environment, populated by an electrical double layer of ions as well as adsorbed natural polyelectrolytes and microbial biofilms. Surface adsorption of underwater bioadhesives likely occurs by exchange of surface bound ligands by amino acid sidechains, driven primarily by relative affinities and effective concentrations of polymeric functional groups. Most aquatic organisms exploit modified amino acid sidechains, in particular phosphorylated serines and hydroxylated tyrosines (dopa), with high‐surface affinity that form coordinative surface complexes. After delivery to the surfaces as a fluid, permanent natural adhesives solidify to bear sustained loads. Mussel plaques are assembled in a manner superficially reminiscent of in vitro layer‐by‐layer strategies, with sequentially delivered layers associated through Fe(dopa)3 coordination bonds. The adhesives of sandcastle worms, caddisfly larva, and barnacles may be delivered in a form somewhat similar to in vitro complex coacervation. Marine adhesives are secreted, or excreted, into seawater that has a significantly higher pH and ionic strength than the internal environment. Empirical evidence suggests these environment triggers could provide minimalistic, fail‐safe timing mechanisms to prevent premature solidification (insolubilization) of the glue within the secretory system, yet allow rapid solidification after secretion. Underwater bioadhesives are further strengthened by secondary covalent curing. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
77.
Stephen G. Davies Ai M. FletcherDeri G. Hughes James A. LeePaul D. Price Paul M. RobertsAngela J. Russell Andrew D. SmithJames E. Thomson Oliver M.H. Williams 《Tetrahedron》2011,67(51):9975-9992
The conjugate addition of an enantiopure lithium amide to a ζ-hydroxy-α,β-unsaturated ester followed by a one-pot ring-closure/N-debenzylation protocol has been used in the asymmetric syntheses of (S)-coniine and (R)-δ-coniceine (isolated as the corresponding hydrochloride salts), and (R,R)-1-(hydroxymethyl)octahydroindolizine (the bicyclic fragment of stellettamides A-C). 相似文献
78.
Wang M Nalla V Jeon S Mamidala V Ji W Tan LS Cooper T Chiang LY 《The journal of physical chemistry. C, Nanomaterials and interfaces》2011,115(38):18552-18559
We demonstrated ultrafast femtosecond nonlinear optical (NLO) absorption characteristics of bilayered fullerosome vesicle nanostructures derived from molecular self-assembly of amphiphilic oligo(ethylene glycolated) C(60)-(light-harvesting diphenylaminofluorene antenna). Fullerene conjugates were designed to enhance photoresponse in a femtosecond time scale by applying an isomerizable periconjugation linker between the C(60) cage and diphenylaminofluorene antenna subunit in an intramolecular contact distance of only < 3.0 ?. Morphology of C(60)(>DPAF-EG(12)C(1))-based fullerosome nanovesicles in H(2)O was characterized to consist of a bilayered shell with a sphere diameter of 20-70 nm and a chromophore shell-width of 9.0-10 nm, fitting well with a head-to-head packing configuration of the molecular length. At the estimated effective nanovesicle concentration as low as 5.5 × 10(-8) MV (molecular molar concentration of 5.0 × 10(-4) M) in H(2)O, two-photon absorption (2PA) phenomena were found to be the dominating photophysical events showing a large molar concentration-insensitive 2PA cross-section value equivalent to 8500 GM in a form of nanovesicles, on average. The observed NLO characteristics led to a sharp trend of efficient light-transmittance intensity reduction at the input laser intensity above 100 GW/cm(2). 相似文献
79.
Russell J. DeOrazio Jun-Ho Maeng Brian A. Sherer Ian L. Scott Sham S. Nikam 《合成通讯》2013,43(23):3551-3555
The double metallation of 6-bromo-3H-benzothiazol-2-one and 6-bromo-3H-benzoxazol-2-one with methyl magnesium bromide and alkyllithium bases is described. Alkylation with a variety of electrophiles occurs at the 6-position of the heterocycles in good yields. 相似文献
80.