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Zhang C Staunton E Andreev YG Bruce PG 《Journal of the American Chemical Society》2005,127(51):18305-18308
Polymer electrolytes, salts dissolved in solid polymers, hold the key to realizing all solid-state devices such as rechargeable lithium batteries, electrochromic displays, or SMART windows. For 25 years conductivity was believed to be confined to amorphous polymer electrolytes, all crystalline polymer electrolytes were thought to be insulators. However, recent results have demonstrated conductivity in crystalline polymer electrolytes, although the levels at room temperature are too low for application. Here we show, for the first time, that it is possible to raise significantly the level of ionic conductivity by aliovalent doping. The conductivity may be raised by 1.5 orders of magnitude if the SbF6- ion in the crystalline conductor poly(ethylene oxide)6:LiSbF6 is replaced by less than 5 mol % SiF6(2-), thus introducing additional, mobile, Li+ ions into the structure to maintain electroneutrality. 相似文献
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A tetraketide synthase containing a loading module (LM), the extension modules erythromycin module 1, rapamycin module 2, and erythromycin module 2 (LM-Ery1-Rap2-Ery2-TE), when expressed in Saccharopolyspora erythraea strain JC2, produced as previously reported a mixture of tetraketide lactones (minor products) and triketide lactones (major products). Several alternative plausible mechanisms by which this "skipping" phenomenon might occur may be proposed. Site-directed mutagenesis of the ketosynthase (KS) and acylcarrier protein (ACP) domains in the interpolated module has shown that skipping within the hybrid PKS involves passage of the growing polyketide through the interpolated module, by direct ACP-to-ACP transfer of the polyketide chain. 相似文献
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Pascarelli S Ruffoni MP Trapananti A Mathon O Aquilanti G Ostanin S Staunton JB Pettifer RF 《Physical review letters》2007,99(23):237204
Using x-ray absorption spectroscopy, we have studied the effect of pressure on femtometer-scale bond strain due to anisotropic magnetostriction in a thin FeCo film. At 7 GPa local magnetostrictive strain is found to be larger than at ambient, in agreement with spin-polarized ab initio electronic structure calculations, but contrary to the expected effect of compression on bond stiffness. The availability of high pressure data on local magnetostrictive strain opens new capabilities for validating theoretical predictions and can lead to the development of materials with the desired properties. 相似文献
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On the basis of an ab initio theory of metallic magnetism in layered materials, we investigate the onset of magnetic order in thin (2-8 layers) fcc-Fe films on and embedded in Cu(100) substrates. In particular, we find an oscillatory dependence of the Curie temperatures on embedding depth, in excellent agreement with experimental data. The thermally induced spin fluctuations are treated within a mean-field disordered local moment picture and give rise to layer-dependent "local exchange splittings" in the electronic structure even in the paramagnetic phase. These features determine the magnetic intralayer and interlayer interactions which are strongly influenced by the presence and extent of the Cu cap. 相似文献
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Staunton E Christie AM Andreev YG Slawin AM Bruce PG 《Chemical communications (Cambridge, England)》2004,(2):148-149
We show that the structure of a polymer electrolyte may be solved by growing single crystals of an oligomeric (short chain) complex which provided an adequate starting model for refinement of the equivalent polymeric structure using powder diffraction: the efficacy of this method has been demonstrated by determining for the first time the structure of an 8 : 1 complex, poly(ethylene oxide)(8) : NaBPh(4). 相似文献
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Hong H Gates PJ Staunton J Stinear T Cole ST Leadlay PF Spencer JB 《Chemical communications (Cambridge, England)》2003,(22):2822-2823
LC-MSn analysis of mycolactone toxin from extracts of Mycobacterium ulcerans has shown that minor co-metabolites, including two previously unreported, differ structurally from mycolactone only in a small portion of the polyketide side-chain. 相似文献
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