In this paper, Ni0.6Mn0.2Co0.2(OH)2 precursors with several different morphologies and particle sizes are mixed with Li2CO3 and heat treated for 5, 7.5 and 10 h. The effects of the precursor properties on the degree of lithiation, electrochemical properties and volumetric capacities of lithiated product are compared. Based on the characterization results, a small (3 μm), narrow span precursor can be lithiated in a short period of time (5 h) and has good initial discharge capacity (185 mA h g??1) and capacity retention (93% for 55 cycles). In contrast, a large wide-span precursor requires over 10 h for full lithiation. A highly porous precursor can be lithiated faster than traditional large wide-span materials, and has low cation mixing and good crystallinity. However, the volumetric energy density of porous material is low after lithiation compared to the other tested materials. Capacity retention after washing correlated with crystallographic properties of the sample.
PVA based hydrogels were synthesised using, as crosslinking agent, trisodium trimetaphosphate (STMP) to obtain potential substitutes
for the vitreous body of the eye. The hydrogels, obtained using different amounts of STMP, were characterised by Infrared
Spectroscopy which confirmed the successful occurrence of crosslinking reaction. The mechanical spectra of the fully hydrated
samples confirmed covalently crosslinked systems (i.e. G′ > G″). The rheological analysis pointed out that only one of the
hydrogels (PVA STMP 8:1) showed a behaviour similar to that of human vitreous. The hydrogel was also subjected to injection
through a small needle, a procedure that is essential in the use of vitreous substitutes. Further analysis in terms of light
transmittance, water content measurements, diffusion coefficient and cytotoxicity confirmed the applicability of such a hydrogel
as vitreous substitute. 相似文献
The essential oil of the flowering aerial parts of Teucrium scorodonia L. ssp. scorodonia growing in Italy on Verrucano, was analyzed by GC and GC–MS. All the identified compounds were sesquiterpene hydrocarbons. The main ones were germacrene B (26.2%) and β-caryophyllene (25.2%). 相似文献
A theory of reason, language and their interconnection constitutes a research topic of epistemological, ontological and metaphysical significance. It also represents a crucial point of contention between defenders and detractors of postmodernism. Therefore, in this article we set out to discuss its stakes and search for its most accomplished philosophical treatment, such as to clarify and justify new curricular premises and overcome disabling and obsolete dichotomies. To accomplish this task, we explore modernist and postmodernist conceptions of reason and single out Apel and Habermas's coupling of rationality and language and its convergence with Derrida's insights on thought and meaning. We argue that such a framework provides education with prospects for new and important curricular directions and emphases. 相似文献
As bacteria grow and proliferate, they release a variety of volatile compounds that can be profiled and used for speciation, providing an approach amenable to disease diagnosis through quick analysis of clinical cultures as well as patient breath analysis. As a practical alternative to mass spectrometry detection and whole cell pyrolysis approaches, we have developed methodology that involves detection via a sensitive, micromachined differential mobility spectrometer (microDMx), for sampling headspace gases produced by bacteria growing in liquid culture. We have applied pattern discovery/recognition algorithms (ProteomeQuest) to analyze headspace gas spectra generated by microDMx to reliably discern multiple species of bacteria in vitro: Escherichia coli, Bacillus subtilis, Bacillus thuringiensis, and Mycobacterium smegmatis. The overall accuracy for identifying volatile profiles of a species within the 95% confidence interval for the two highest accuracy models evolved was between 70.4 and 89.3% based upon the coordinated expression of between 5 and 11 features. These encouraging in vitro results suggest that the microDMx technology, coupled with bioinformatics data analysis, has potential for diagnosis of bacterial infections. 相似文献