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1.
Brian Lawn David Marshall Rishi Raj Greg Hirth Trevor Page Julie Yeomans 《Journal of the American Ceramic Society》2021,104(1):23-26
Crystalline quartz has long been identified as among the weakest of abundant crustal minerals. This weakness is particularly evident around the α–β phase inversion at 573°C, in which Si–O bonds undergo a displacive structural transformation from trigonal to hexagonal symmetry. Here we present data using indentation testing methodologies that highlight the precipitous extent of the transformational weakening. Although the indentations are localized over relatively small specimen contact areas, the data quantify the essential deformation and fracture properties of quartz in a predominantly (but not exclusively) compressive stress field, at temperatures and pressures pertinent to conditions in the earth's crust. 相似文献
2.
Manjin Kim Qinfen Gu Tanveer Hussain Yahia Ali Trevor B. Abbott Kazuhiro Nogita 《International Journal of Hydrogen Energy》2021,46(53):27096-27106
With superior properties of Mg such as high hydrogen storage capacity (7.6 wt% H/MgH2), low price, and low density, Mg has been widely studied as a promising candidate for solid-state hydrogen storage systems. However, a harsh activation procedure, slow hydrogenation/dehydrogenation process, and a high temperature for dehydrogenation prevent the use of Mg-based metal hydrides for practical applications. For these reasons, Mg-based alloys for hydrogen storage systems are generally alloyed with other elements to improve hydrogen sorption properties. In this article, we have added Na to cast Mg–La alloys and achieved a significant improvement in hydrogen absorption kinetics during the first activation cycle. The role of Na in Mg–La has been discussed based on the findings from microstructural observations, crystallography, and first principles calculations based on density functional theory. From our results in this study, we have found that the Na doped surface of Mg–La alloy systems have a lower adsorption energy for H2 compared to Na-free surfaces which facilitates adsorption and dissociation of hydrogen molecules leading to improvement of absorption kinetic. The effect of Na on the microstructure of these alloys, such as eutectic refinement and a density of twins is not highly correlated with absorption kinetics. 相似文献
3.
4.
Warren J. Batchelor Trevor R. Finlayson Anita K. Gross 《Journal of the American Ceramic Society》1993,76(7):1895-1897
The measured plastic deformation of Mg-PSZ under stress contains contributions from both transformation and microcracking. A method is described to separate the contributions from transformation and microcracking for samples deformed in uniaxial tension. Such a separation enables the ratio of the longitudinal to transverse strains arising from the transformation to be estimated. The results are compared to the predictions of the shear–dilatation model of Chen and Reyes-Morel. Serious discrepancies are found between the experimental results and the predictions of the model and the possible reason for this is discussed. 相似文献
5.
Synthesis and Characterisation of Some New Ferrocenyl- and Ferrocenylalkynyl-[60]Fullerene Compounds
David J. Cardin Trevor Gibson Jason A. Peel 《Fullerenes, Nanotubes and Carbon Nanostructures》1997,5(4):681-694
We report the synthesis and characterisation of a series of ferrocenylfullerene compounds, and some new ferrocene derivatives required as intermediates. The new fullerene species are Fc-[60]fullerene, (8); Fc-C=C-[60]fullerene, (10); Fc-C=C-C=C-[60]fullerene, (12); and (η-C5H4SiBu3)Fe(η-C5H4)-[60]fullerene, (14). 相似文献
6.
Trevor A. Williams 《Computer Supported Cooperative Work (CSCW)》1995,4(4):281-296
This paper examines whether information technology can play a strategic role in supporting regulatory reforms aimed at achieving
voluntary cooperation with government regulation. Analysis of the case of electronic tax return lodgment in Australia suggests
that the effects of IT are contextual, and identifies positive effects of the new IT system on voluntary cooperation. However,
in this case, divergence between private and public interests and uncertainty and lack of participation in regulatory decision-making
appear to restrict the development of voluntary cooperation as a primary basis for government regulation. 相似文献
7.
Trevor Bench-Capon Katie Atkinson Peter McBurney 《Autonomous Agents and Multi-Agent Systems》2012,25(1):183-208
In this paper we demonstrate how a qualitative framework for decision making can be used to model scenarios from experimental
economic studies and we show how our approach explains the results that have been reported from such studies. Our framework
is an argumentation-based one in which the social values promoted or demoted by alternative action options are explicitly
represented. Our particular representation is used to model the Dictator Game and the Ultimatum Game, which are simple interactions
in which it must be decided how a sum of money will be divided between the players in the games. Studies have been conducted
into how humans act in such games and the results are not explained by a decision-model that assumes that the participants
are purely self-interested utility-maximisers. Some studies further suggest that differences in choices made in different
cultures may reflect their day to day behaviour, which can in turn be related to the values of the subjects, and how they
order their values. In this paper we show how these interactions can be modelled in agent systems in a framework that makes
explicit the reasons for the agents’ choices based upon their social values. Our framework is intended for use in situations
where agents are required to be adaptable, for example, where agents may prefer different outcome states in transactions involving
different types of counter-parties. 相似文献
8.
The hexane-soluble fractions of hydroliquefied products from three Yallourn brown coal lithotypes have been separated into five fractions by combined silica-alumina packed column chromatography. Analyses of various fractions by g.c.-m.s. permitted the identification of ≈50 components in the saturate fraction and 40 components in the diaromatic fraction, together with 30 components in the monoaromatics. The components identified were quite similar among hexane-soluble portions of all three lithotypes. A marked predominance of even carbon number alkane (C23-C29) was observed in the hydrocarbon fractions from pale lithotype over , and medium light lithotype over both pure ZnCl2 and . However, medium dark lithotype over both melt catalysts produced a saturate fraction with an odd carbon number(C22-C28) preference. Based on spectral methods, Soxhlet extracts obtained from untreated lithotypes (hexane and benzene solubles) were characterized as complex mixtures of higher molecular weight(300–1000) aliphatic hydrocarbons, which were supposed to be a precursor of the saturates produced from the corresponding lithotype in the catalytic hydroliquefaction. 相似文献
9.
The iron phases present in an electrostatic precipitator ash, an uncooled ash deposit and a cooled superheater ash deposit from Hazelwood Power Station, Australia, burning Morwell brown coal has been examined using Mössbauer spectroscopy. The principal iron phase in the precipitator ash and the uncooled ash deposit from a hot gas offtake was calcium aluminoferrite (Ca2Fe2 ? xAlxO5). Minor amounts of hematite (α-Fe2O3) and magnetite (Fe3O4) were also detected in the precipitator ash. The cooled superheater ash deposit contained a (Mg, Fe, Al) oxide spinel as the primary iron phase; small quantities of hematite were also detected in this deposit close to the heat exchanger interface. The formation of these iron phases has been rationalized on the basis of the average composition of coal delivered to the power station and supplementary ash chemistry data obtained from other techniques. The evidence suggests that the calcium aluminoferrite in the precipitator ash is derived from inorganic constituents (distributed throughout the coal organic matrix) and the hematite and magnetite are of mineral origin (discrete particles). 相似文献
10.
第一批人凝血因子Ⅶ浓制剂国家标准品协作标定 总被引:1,自引:0,他引:1
目的 协作标定第一批人凝血因子Ⅶ浓制剂国家标准品。方法 以 WHO 97/592批人凝血因子Ⅶ浓制剂国际标准品为对照,采用一期法标定我国首批人凝血因子Ⅶ因家标准品,并将标准品分别置4℃、22℃、37℃保存5个月,用加速破坏试验进行稳定性考查。结果 该批标准品效价为16.0IU/支,稳定性良好。其他项目均达到国家标准品要求。结论 已成功研制第一批人凝血因子Ⅶ浓制剂国家标准品。 相似文献