Pawley and Rietveld refinements using electron diffraction from L1₂-type intermetallic Au₃Fe₁-x nanocrystals during their in-situ order-disorder transition

During the in-situ order-disorder transition of intermetallic L1₂-type Au₃Fe_1−x nanocrystals, structural information has been retrieved from their electron diffraction patterns based on the Pawley refinement that is unrelated to the electron kinematical or dynamical scattering nature as well as the Rietveld refinement using a kinematical approximation. At room temperature, it was found that the nanocrystals contain approximately x=40% vacancies at the Fe site. Based on in-situ heating this phase displayed an irreversible order-disorder transition, with the transition temperature between 553 and 593 K. A sudden increase in lattice parameter was detected during the first heating from the ordered phase, while the second heating of the disordered phase showed only a linear relationship with temperature. From the lattice parameter measurement of the disordered phase, the coefficient of thermal expansion was estimated as 1.462×10⁻⁵ K⁻¹. The long-range order parameter S was determined by the refined site occupancies, as well as the integrated intensities of the superlattice (1 0 0) and fundamental (2 2 0) reflections using the Pawley and Rietveld refinements during the order-disorder transition. Considering the dynamical scattering effect, Blackman two-beam approximation theory was applied to corrected S, which slightly attenuated after the correction. A comparison of the electron diffraction with X-ray diffraction data was made. It was demonstrated that elemental and structural information could be retrieved through quantitative electron diffraction studies of the nanomaterials. Since the Pawley refinement algorithm does not include the electron scattering event, it is especially useful to refine the electron diffraction data regardless of the sample thickness.     

Why are some Spanish regions more resilient than others?

Which of a region's characteristics most strongly influence its degree of resilience? This study constructs a composite resilience index for the Spanish regions and uses Multiple Factor Analysis to compare it with the Martin resilience index (Martin, 2012). The results of a Principal Components Analysis to measure the relative contributions of potential regional resilience drivers indicate that, during recovery periods, it is market- service focused regional economies that show stronger resilience, while, in crisis periods, it is regions with a more highly-educated workforce.     

Aroma profile and physico‐chemical properties of artisanal honey from Tabasco,Mexico

The aim of this work was to characterise, physico‐chemically, sugar composition and aroma profile of ten honey samples collected by small producers during two seasons and produced in different agricultural ecosystems from Tabasco State (Mexico). The mean values obtained for the physico‐chemical parameters were: pH 3.63; 19.25% moisture; 78.8°Brix sugar; 0.64% ash; 0.25 mS cm^?1 electrical conductivity and 0.58 water activity. Based on colour parameters, Tabasco honeys can be placed in the group of dark honeys. In the analysed samples; fructose was the major sugar (39.45%), followed by glucose (35.74%) while sucrose only represented 2.93%. The volatile profiles of the ten honey samples were obtained by gas chromatography‐mass spectrometry. All the honeys were characterised by their high contents of benzene and furan‐related compounds. As a result, artisanal honeys from Tabasco (Mexico) can be considered to present a good level of quality.     

香奈儿背话的家族

“我们是一个很谨慎的家族．（对香奈儿）我们从来不说什么。香奈儿是关于可可·夏奈尔的，是关于卡尔的，是关于每一个在香奈儿工作、创作的人的．而不是关于维德摩尔家族的。”     

Automatic provision of personalized e-commerce services in Digital TV scenarios with impermanent connectivity

Digital TV (DTV) bears much potential for e-commerce, but most of it remains underexploited due to the lack of systematic approaches to the provision of interactive applications. Working on top of an existing recommender system, this paper presents mechanisms to automatically compose applications that provide personalized commercial functionalities to the users. The proposal addresses specific concerns of DTV environments, with special attention to achieving good personalization quality and furnishing useful interactions when there is no return channel permanently available for bidirectional communication. Preliminary experiments reveal good acceptance of the concept among real users.     

Control of the Basicity in Ni–MgO Systems: Influence in the Hydrogenation of Styrene Oxide

The addition of basic solutions to the reaction medium in the catalytic hydrogenation of styrene oxide improves the selectivity to 2-phenylethanol (used in perfumery) but also can favour condensation reactions. To study the influence of different basic sites on the reaction products, we prepared several catalysts by mixing a commercial magnesia (MgO), and other previously rehydrated (MgOr), with different amounts of NiO followed by reduction (NiMgO, 4NiMgO, NiMgOr, 4NiMgOr), and by mixing directly MgO with Ni (NiMgOa, 4NiMgOa). Ni–MgO catalysts showed the best conversion and selectivity to 2-phenylethanol values, arriving to 100% when increasing the MgO content. Interestingly, CO₂-TPD study of catalyst NiMgO indicates that metallic nickel covers the weakest basic sites of magnesia. On the other hand, CO₂-TPD profiles of Ni–MgOr and Ni–MgOa catalysts, which present low catalytic activity, showed an important amount of available basic sites that favour the formation of higher amounts of condensation products, which are responsible for the catalyst deactivation.     

Response of Epilachna paenulata to Two Flavonoids, Pinocembrin and Quercetin, in a Comparative Study

We examined the effects of the flavonoids pinocembrin and quercetin on the feeding behavior, survival, and development of the Cucurbitaceae pest Epilachna paenulata (Coleoptera: Coccinellidae). In no-choice experiments, 48 hr-consumption of Cucurbita maxima Duch. leaves treated with pinocembrin at 1, 5, and 50 μg/cm² was less than one third of that for leaves treated with 0.1 μg/cm² of pinocembrin or untreated leaves. Larvae stopped feeding after 9 days of high doses of pinocembrin (5 and 50 μg/cm²), and larval weight and survival were negatively affected by pinocembrin at 1–50 μg/cm². Delayed mortality in comparison to food-deprived larvae suggests that the mechanism of action for pinocembrin is chronic intoxication, rather than simple starvation from antifeedant effects. In contrast, leaf consumption and larval weight were not significantly affected by quercetin (at 0.1, 1, 5, and 50 μg/cm²) while mortality rates were only slightly increased. The response of E. paenulata larvae in a choice-test to combinations of pinocembrin at antifeedant doses (5 and 50 μg/cm²) and quercetin at phagostimulant doses (0.01 and 0.1 μg/cm²) indicated that the feeding deterrent activity of the former completely overshadowed the stimulant activity of the latter. These results demonstrate the different responses of one insect species to two widely distributed plant flavonoids. Pinocembrin strongly affected survival of E. paenulata while quercetin had only a weak effect without major consequences on the insect life-cycle.     

Characterization of an anionic-exchange membranes for direct methanol alkaline fuel cells

Ammonium quaternized polymers such as poly (arylene ether sulfones) are being developed and studied as candidates of ionomeric materials for application in alkaline fuel cells, due to their low cost and promising electrochemical properties. In this work, a quaternary ammonium polymer was synthesized by chloromethylation of a commercial polysulfone followed by amination process.     

Bioactive action of β‐glucosidase enzyme of Bifidobacterium longum upon isoflavone glucosides present in soymilk

Bioconversion of isoflavone glucosides and antioxidant activity by probiotic strain (Bifidobacterium longum) during soymilk fermentation was investigated, as well as partial characterisation of the produced enzyme β‐glucosidase. The enzyme has higher affinity for genistin than for other substrates assayed. Maximum activity occurred at 42 °C and at pH 6.0; keeping 70–80% of activity for 60 days stored at low temperatures. Bifidobacterium longum grew well in soymilk (8.26 log CFU mL^?1 and pH of 3.9 at 24 h) and were produced in good quantities of organic acids. High hydrolysis degree of isoflavone glucosides (81.2%) was observed at 24 h. Enhancements in bioactivity were assessed in fermented soymilk by monitoring the radical‐scavenging activity, antioxidant activity and DNA protective action. The use of probiotic Bifidobacterium strain as β‐glucosidase producer increased bioactive isoflavone content and demonstrated that this enzyme plays a key role in the bioavailability of soymilk isoflavones, reducing the bioconversion time compared to other studies.