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991.
Various approaches have been reported during the last decade to enhance the photo-catalytic and super-hydrophilic characteristics of the intrinsic TiO2 materials. Results on the photo-degradation activity of RF-sputtered nitrogen-doped titania thin films are presented here with respect to two environmental pollutants in gas- and liquid phases, as a function of dopant concentration. This study was accomplished by monitoring the time dependence of pollutant concentration in contact with the films, both under UV and solar light illumination. The synergic effects of surface morphology, crystalline and electronic structure of the materials are discussed in relation with the observed experimental facts. The results presented here show a close correlation between the oxidative power of the films and their previously reported wettability features.  相似文献   
992.
The objective was to examine the relationships between serum ferritin, alcohol intake, and socioeconomic factors (school education, occupational education, occupation, income, marital status, cohabitation status, housing, social class) in a population survey performed in Copenhagen County during 1982-1984. The participants were selected at random from the census register and comprised 2235 healthy Danish individuals, non-blood donors (1044 men, 1191 women) in cohorts being 30, 40, 50, and 60 years old. The participants gave a detailed social and medical history and had a clinical examination including blood samples. In all age-groups, men had significantly higher serum ferritin and alcohol intake than women. In men, there was no relationship between serum ferritin and social class. Significant relationships were observed between ferritin and occupation (unemployed and self-employed men had higher ferritin than those with other occupations) and ferritin and income (in younger men, ferritin displayed a steady increase with income). None of the social variables were related to the prevalence of iron deficiency or iron overload. Alcohol intake was related to occupation and income, but not to social class. In women, none of the social variables showed any significant relationship to ferritin levels or iron overload. The prevalence of small iron stores (serum ferritin < or = 30 micrograms/l) was lower and the intake of alcohol was higher in women from high social classes. In both men and women, serum ferritin displayed highly significant positive correlations with alcohol intake. Likewise, the prevalence of iron overload (serum ferritin > 90th percentile) was closely correlated to alcohol intake. In conclusion, socioeconomic factors per se had a minor influence on serum ferritin levels and iron status in Danes. The distinct association between alcohol intake and serum ferritin levels should be considered in future iron status surveys.  相似文献   
993.
Refinements have been proposed for the autoregressive conditional duration model within the framework of financial durations. It is argued that a Pareto distribution is a meaningful representation for durations. The model is analyzed under the hypothesis of regime-switching parameters with different transition functions governed both by an observable and a latent variable.  相似文献   
994.
This paper confirms a conjecture of Bergstra and Klop's from 1984 by establishing that the process algebra obtained by adding an auxiliary operator proposed by Hennessy in 1981 to the recursion free fragment of Milner's Calculus of Communicating Systems is not finitely based modulo bisimulation equivalence. Thus, Hennessy's merge cannot replace the left merge and communication merge operators proposed by Bergstra and Klop, at least if a finite axiomatization of parallel composition modulo bisimulation equivalence is desired.  相似文献   
995.
Luca Albertin 《Polymer》2006,47(4):1011-1019
The effect of an added base on the aqueous reversible addition-fragmentation chain transfer polymerization of a methacrylic glycomonomer with (4-cyanopentanoic acid)-4-dithiobenzoate was investigated. When sodium carbonate or sodium bicarbonate were used to dissolve the RAFT agent in aqueous solution at room temperature, an inhibition period of 60-90 min was observed at the beginning of the polymerization together with a marked decrease in the overall polymerization rate. Also, experimental Mn values were much higher than the calculated ones in both cases. When sodium carbonate was used, control over the polymerization process was lost within 43% conversion. Better results were obtained with sodium bicarbonate, in which case the molecular weight distribution remained narrow and unimodal up to 81% conversion. At that point, a higher molecular weight shoulder developed that kept growing in intensity at the proceeding of the reaction. Dramatically improved results were obtained by adding circa 10% ethanol to the polymerization mixture to facilitate the dissolution of (4-cyanopentanoic acid)-4-dithiobenzoate. Following this protocol, narrow polydispersity poly(methyl 6-O-methacryloyl-α-d-glucoside) was obtained possessing a molecular weight close to the predicted value.  相似文献   
996.
In this paper we propose a new characterization of model-based diagnosis based on process algebras, a framework which is widely used in several areas of computer science. We show that process algebras provide a powerful modelling language which allows us to capture, in an uniform way, different types of models of physical systems, including models of time-varying and dynamic behavior. Then we provide a characterization of diagnosis which is equivalent to the “classical” abductive one. This suggests new interesting opportunities for research on relations between model-based reasoning and process algebras.  相似文献   
997.
Polyclonal antibodies have been raised against a highly purified egg yolk protein, which appears to be unaffected by thermal treatments and whose content is constant in eggs of different origin. The antibodies are able to bind specifically to the egg yolk protein and can be used for the quantification of the egg content in egg pasta. For this purpose an indirect ELISA procedure has been developed.  相似文献   
998.
An explicit finite element solution procedure for the three dimensional Euler equations is presented. The solution domain is automatically meshed using a tetrahedral mesh generator which is an extension of our previous two dimensional work. Several examples are included to illustrate the performance of the generator and solver. An adaptive mesh regeneration procedure is used for the first time in three dimensions.  相似文献   
999.
Andrew R. Teel  Luca Zaccarian   《Automatica》2006,42(12):2219-2222
We discuss the lack of “uniformity” in definitions of uniform global asymptotic stability (UGAS) that have been used in various textbooks, monographs, and papers over the years. Sometimes UGAS is taken to be the combination of uniform local stability (ULS) and uniform global attractivity (UGA). Other times it also encompasses uniform global boundedness (UGB). This paper contains an explicit, smooth scalar example that shows that these definitions do not agree in general, even when the right-hand side is locally Lipschitz in the state uniformly in time (and thus bounded in time). We also discuss various notions of global asymptotic stability with relaxed uniformity (with respect to the initial time) requirements for the behavior of the solutions. In particular, we consider class- estimates and Lyapunov characterizations.  相似文献   
1000.
Chagas disease vector insects Triatoma infestans and Rhodnius prolixus (fifteen stage III nymphs per 4 litre cage) were allowed to feed on anaesthetized mice for 1 h (control group), or on active non-anaesthetized mice (NAM) for 2, 4 or 8 h exposure. The bloodmeal size (weight increase) for both species was proportional to the duration of contact with NAM, due to ingestion of multiple small bloodmeals, up to 142% of control weight for T. infestans with 8 h exposure to NAM. The mean weight increase of T. infestans nymphs after 4 h contact with NAM was similar to that of the control group, whereas for R. prolixus, 8 h contact with NAM gave only 64% of the control value. For both species of insect, within 4 h of feeding, > 20% of the bloodmeal weight was lost by defaecation and diuresis. The proportions of unfed nymphs and mortality during 2 h contact with NAM were significantly higher for R. prolixus, demonstrating better exploitation of the host blood source by T. infestans, apparently because during blood-feeding the latter insect species caused less irritation to the host.  相似文献   
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