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1.
We report on the growth and magnetic properties of La2/3Sr1/3MnO3/SrTiO3/CoFe2 hard-soft magnetic systems prepared by pulsed laser deposition on SrTiO3(001) substrates. In situ reflection high-energy electron diffraction along the [100]SrTiO3 substrate azimuth and atomic force microscopy measurements reveal that La2/3Sr1/3MnO3 and SrTiO3 grow both in a three dimensional mode and that the roughness of the lower and upper magnetic/non-magnetic interfaces ranges between 2 and 4 Å. Cross-section transmission electron microscopy observations show that the layers are continuous, with an homogeneous thickness, and that the interfaces are mostly sharp and correlated. The magnetization curves show a two step reversal of the magnetization, with very distinct coercive fields. A small anisotropy is observed for the CoFe2 layer with an in plane easy magnetization axis along the [110]SrTiO3 direction. Minor magnetization loops indicate that the coupling between the magnetic layers is negligible.  相似文献   
2.
Influence of the size effects on the mechanical behavior of face-centered cubic metals was studied for complex loadings close to microforming ones. The effect of a reduction in thickness (t) over grain size (d) ratio on the mechanical behavior for high-purity nickel and copper is investigated for three different loadings by tensile and Nakazima tests (plane strain conditions and balanced biaxial expansion). Experimental results highlight a strong degradation of the mechanical properties of Cu and Ni when the t/d ratio is reduced below a critical value, independently of the strain path. However, this effect occurs if the equivalent plastic strain is larger than a critical level which is strain path dependent and related to the stress triaxiality. The current study reveals that plastic anisotropy is also affected by size effects. An excellent correlation is obtained between the t/d ratio and the thickness reduction, through the mean normal plastic anisotropy parameter which is widely used to estimate sheet formability. A size effect map based on forming limit diagrams is proposed to depict the optimal conditions of microforming.  相似文献   
3.
Nucleophosmin-1 (NPM1) is a pleiotropic protein involved in numerous cellular processes. NPM1 shuttles between the nucleus and the cytoplasm, but exhibits a predominant nucleolar localization, where its fate and functions are exquisitely controlled by dynamic post-translational modifications (PTM). Sentrin/SUMO Specific Peptidase 3 (SENP3) and ARF are two nucleolar proteins involved in NPM1 PTMs. SENP3 antagonizes ARF-mediated NPM1 SUMOylation, to promote ribosomal biogenesis. In Acute Myeloid Leukemia (AML), NPM1 is frequently mutated, and exhibits an aberrant cytoplasmic localization (NPM1c). NPM1c mutations define a separate AML entity with good prognosis in some AML patients, rendering NPM1c as a potential therapeutic target. SENP3-mediated NPM1 de-SUMOylation induces resistance to therapy in NPM1c AML. Here, we demonstrate that the imidazoquinoxaline EAPB0503 prolongs the survival and results in selective reduction in the leukemia burden of NPM1c AML xenograft mice. Indeed, EAPB0503 selectively downregulates HDM2 expression and activates the p53 pathway in NPM1c expressing cells, resulting in apoptosis. Importantly, we unraveled that NPM1c expressing cells exhibit low basal levels of SUMOylation paralleled with high SENP3 and low ARF basal levels. EAPB0503 reverted these molecular players by inducing NPM1c SUMOylation and ubiquitylation, leading to its proteasomal degradation. EAPB0503-induced NPM1c SUMOylation is concurrent with SENP3 downregulation and ARF upregulation in NPM1c expressing cells. Collectively, these results provide a strong rationale for testing therapies modulating NPM1c post-translational modifications in the management of NPM1c AML.  相似文献   
4.
Shape memory alloys (SMA) are being more frequently integrated into engineering applications. These materials with their shape memory effect enable the simplification of mechanisms and the reduction in size of actuators. SMA parts can easily be activated by Joule effect but their modeling and consequently their control remains difficult. It is principally due to their non-linear hysteretic thermomechanical behavior. Most of successful control strategies applied to SMA actuators are not often suitable for industrial applications: they are particularly heavy and use the Preisach model or neural networks to model the hysteretic behavior of these materials; this kind of model is difficult to identify and to use in real time. This paper deals with an application of the new framework of model-free control (MFC) of an SMA-spring based actuator. This control strategy relies on new results for fast derivative estimation of noisy signals. Their main advantages are: its simplicity and its robustness. Experimental results and comparisons with PI control are presented that demonstrate the efficiency of this new control strategy.  相似文献   
5.
Stable isotope ratio analysis for authentication of lamb meat   总被引:4,自引:0,他引:4  
The effectiveness of the analysis of stable isotope ratios ((13)C/(12)C and (15)N/(14)N) in fractions of lamb meat, measured by isotope ratio mass spectrometry, was evaluated as a method of feeding and geographical origin authentication. Analyses were carried out on meat from 12 lamb types, produced in couples in six European countries (country of origin, CO) and divided in three groups according to the feeding regime during their finishing period: suckled milk only, pasture without any solid supplementation and supplementation containing maize grain (feeding regime, FR). These analyses were made on two samples of longissimus thoracis muscle, taken from the 13th rib section of the left side of two different lambs, randomly chosen between the 120 selected to represent each lamb type. δ(13)C values varied significantly in different meat fractions, the difference being higher in protein than in fat (average difference 5.0‰). However, the pairs δ(13)C values of crude fat and protein were highly correlated (r=0.976) and affected by lamb type in a similar fashion, mainly reflecting animals' feeding regime. Even δ(15)N values of meat protein fraction showed significant differences between lamb types, not dependant on the feeding regime. In fact, lambs fed on similar diets, but in different countries, gave meat with different (15)N relative abundances. These findings provide the possibility of discriminating lamb types within the same feeding regime. Canonical discriminant analysis was carried out to evaluate whether lamb meat from different CO or FR or CO×FR interaction could be mathematically distinguished by its stable isotope ratios. On the basis of CO, the corrected empirical allocation of 79.2% of the initial observations and the corrected cross-validation of two thirds of the individual meat samples was obtained. FR gave better results: 91.7% of the individual meat samples was both correctly allocated and cross-validated, indicating the high potential of stable isotope ratio analysis as a tool for lamb diet characterisation. The most satisfactory classification attained, using K-means clustering technique and canonical discriminant analysis, enabled a good resolution of six CO×FR groups of lamb types: Icelandic fed on pasture; British and French grazing; Italian; suckled and Karagouniko concentrates finished; French Lacaune; Ternasco de Aragon. It was concluded that multielement stable isotope analysis may be considered promising for the reliable evaluation of lamb meat authenticity, in the same way as for wine, fruit juice, honey and dairy products.  相似文献   
6.
The site-specific natural isotope fractionationnuclear magnetic resonance (SNIF-NMR)2H analysis is at present the reference method for determining the origin of ethanol and has been successfully applied for analysing all grape products. The method has also been used to identify the origin of wines and the aim of this study was to verify this application. In all, 3309 samples belonging to the Italian wines data bank were analysed from all 20 Italian regions to study the possibilities of determining and controlling the exact origin and year of the product. The dependency of the deuterium/hydrogen ratio of the methyl site (D/HI) with latitude was confirmed but this was not the case for the D/H ratio of the methylene site (D/HII) and the parameter R [2(D/HII)/(D/HI)] did not add any additional information. The frequency distribution of the NMR parameters follows a regular North-South gradient but they are not sufficiently different in each region to allow unique characterisation. The lack of effectiveness of the method, when applied to identification, depends on interannual and interregional variability. As a consequence, all but some very different regions overlap. The SNIF-NMR method is particularly suitable for detecting simple adulterations but, in the Italian situation, seems not to be so useful for solving problems of geographical origin. For this, it could be helpful to use other isotopic parameters and to ameliorate the sampling technique, to improve the effectiveness of the method.
Regionale und jährliche Variabilität des Ethanolgebundenen Deuteriumgehaltes italienischer Weine
Zusammenfassung Die SNIF-NMR2H-Analytik wird derzeit als Referenzmethode zur Bestimmung der Herkunft des Ethanols bei Produkten aus Weintrauben erfolgreich angewandt. Die Methode wird auch zur Ermittlung der geographischen Herkunft von Wein eingesetzt. Ziel der vorliegenden Arbeit war es, die Brauchbarkeit dieser Analysenmethode zur Bestimmung des geographischen Ursprungs italienischer Weine zu überprüfen. Dazu wurden Analysenergebnisse von 3309 Weinen aus allen 20 Weinbaugebieten Italiens im Rahmen einer Datenbank des D/H-Verhältnisses gesammelt. Während für die D/HI-Werte eine deutliche Abhängigkeit von der geographischen Breite bestätigt werden konnte, zeigten die D/HII-Werte keinen derartigen Zusammenhang. Auch der Parameter R erbrachte keine weiteren Informationen. Die Häufigkeits-Verteilung der NMR-Werte folgt deutlich einem Nord-Süd-Gradienten, aber sie sind nicht in jeder Region so unterschiedlich, daß eine signifikante Differenzierung möglich ist. Dies resultiert aus den jahrgangs- und gebietsabhängigen Schwankungen. Die SNIF-NMR Methode ist zur Aufklärung bestimmter Verfälschungen (Zuckerzusatz) gut geeignet, bei italienischen Weinen ist jedoch mit dieser Methode das Problem der Bestimmung der geographischen Herkunft nicht lösbar. Durch Messung weiterer stabiler Isotopen sowie durch eine Verbesserung der Probennahme kann eine Erhöhung der Effizienz zum Nachweis der geographischen Herkunft erzielt werden.
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7.
The free aroma compounds of wines were isolated by liquid-liquid extraction with a mixture of trichlorofluoromethane/dichloromethane whereas the enrichment of glycosidically bound aroma components was carried out by adsorption on XAD and subsequent elution with various solvents. The glycosidic compounds were liberated enzymatically byβ-glucosidases. The extracts were analysed by gas chromatography. In 92 wines of the varieties Riesling, Weißburgunder, Silvaner and Ruländer of three vintages (1989, 1990, 1991), from different regions and wine producers 160 free aroma compounds were quantitatively determined. By use of statistical analysis the components were reduced to 23 significant aroma constituents. Analytical characterization of the investigated grape varieties was possible with these components. Terpene compounds, unsaturated C6-alcohols and some components of the amino acid metabolism were especially typical for the varietal character. Using 18 glycosidically bound aroma substances it could be shown that these components can also contribute significantly to the characterization of grape varieties where monoterpenes and norisoprenoids play an important role. Computing at the same time free and glycosidically bound aroma components in discriminant analysis the characterization of neutral grape varieties (Silvaner, Ruländer, Weissburgunder) can be considerably improved.  相似文献   
8.
At the building scale, green roof has demonstrated a positive impact on urban runoff (decrease in the peak discharge and runoff volume). This work aims to study if similar impacts can be observed at a basin scale. It is particularly focused on the possibility to solve some operational issues caused by storm water.

For this purpose, a methodology has been proposed. It combines: a method to estimate the maximum roof area that can be covered by green roof, called green roofing potential, and an urban rainfall-runoff model able to simulate the hydrological behaviour of green roof.

This methodology was applied to two urban catchments, one affected by flooding and the other one by combined sewage overflow. The results show that green roof can reduce the frequency and the magnitude of such problems depending on the covered roof surface. Combined with other infrastructures, they represent an interesting solution for urban water management.  相似文献   

9.
Mobile code is slowly gaining acceptance but it is still not clear where it is really useful. If not used judiciously it may incur greater complexity of programming and degradation of performances. The goal of this paper is to show that mobile code is particularly well suited as a glue for the composition of immobile services, where flexibility and extensibility are necessary. To support our claim we describe two services and one application that have been programmed with mobile code in the context of active networking. We study the impact on the flexibility, complexity and performance of the resulting systems. We observe positive effects on flexibility and complexity and acceptable performance penalties.  相似文献   
10.
The aim of this study was to characterize the isotopic composition and protect “Peretta” cows’ milk cheese, a typical product of Sardinia, against other cheeses of the same appearance sold under the same name, but made of raw materials from northern Europe. The study was concerned with 3 types of cheese: those produced in local dairies from milk from free-grazing or pasture-grazing cows in Sardinia (local dairy product), cheeses made on an industrial scale from milk produced by intensive farming in Sardinia (factory cheese), and cheeses made with raw materials imported from other countries (imported product). To distinguish the Sardinian cheeses from the imported product, the stable isotope ratios 13C/12C, 15N/14N, D/H, 34S/32S, and 18O/16O were used. Determination of the isotopic data δ13C, δ15N, δ2H, and δ34S was performed in the casein fraction, whereas δ18O and δ13C were determined in the glycerol fraction. Measurements were performed by isotope ratio mass spectrometry. A comparison between mean values of the isotope ratios by statistical analysis (ANOVA and Tukey's test) showed that the greatest difference between the 3 types of cheese (local dairy, factory, and imported products) was in the 13C/12C, 34S/32S, and 18O/16O isotope ratios. In the other parameters, either no differences (δ15N) or minimal differences (δ2H) were found. Evaluation of the data by multivariate statistical analysis (principal component analysis and hierarchical cluster analysis) revealed that the isotope characteristics of the factory products were similar to those of the cheeses produced from imported raw materials, whereas a difference was found between the local dairy-produced cheeses and the products in the other 2 categories.  相似文献   
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