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991.
Danko Nikolić 《国际自动化与计算杂志》2017,14(5):532-541
The recently introduced theory of practopoiesis offers an account on how adaptive intelligent systems are organized. According to that theory, biological agents adapt at three levels of organization and this structure applies also to our brains. This is referred to as tri-traversal theory of the organization of mind or for short, a T3-structure. To implement a similar T3-organization in an artificially intelligent agent, it is necessary to have multiple policies, as usually used as a concept in the theory of reinforcement learning. These policies have to form a hierarchy. We define adaptive practopoietic systems in terms of hierarchy of policies and calculate whether the total variety of behavior required by real-life conditions of an adult human can be satisfactorily accounted for by a traditional approach to artificial intelligence based on T2-agents, or whether a T3-agent is needed instead. We conclude that the complexity of real life can be dealt with appropriately only by a T3-agent. This means that the current approaches to artificial intelligence, such as deep architectures of neural networks, will not suffice with fixed network architectures. Rather, they will need to be equipped with intelligent mechanisms that rapidly alter the architectures of those networks. 相似文献
992.
Sanja Vlaisavljević Biljana Kaurinović Mira Popović Sanja Vasiljević 《International Journal of Food Properties》2017,20(12):3090-3101
Although Trifolium pratense (Red Clover) is considered to be one of the leading crops for livestock grazing, it could also be used as a potential source of bioactive compounds in phytopharmacy. The aim of this study was to investigate the phenolic content and its biological activity at the growth phases (30 cm, 50 cm, and bud) of this plant. The phenolic compounds in methanolic extracts of T. pratense leaves at three growth stages, obtained by Microwave Assisted Extraction, were quantified using the HPLC-ESI-MS/MS technique, and their antioxidant and antimicrobial activity were assessed. Isoflavonoids, genistein, and daidzein, as well as other phenols, p-hydroxybenzoic and caffeic acids, kaempferol 3-O-glucoside, quercetin 3-O-glucoside, and hyperoside were found in all the extracts, but the content of these compounds was the highest in the extract of the plant at the lowest growth stage (30 cm, vegetative). Therefore, this extract showed the best antioxidant potential and it was most effective against bacterial strains such as Escherichia coli and Enterobacter aerogenes. These results indicated that red clover has potential health benefits, and that growth phase contributes to its biological activity. The extract of red clover at the growth stage of 30 cm is a great source of bioactive compounds and could be used in phytotherapy and nutrition. 相似文献
993.
Ana-Marija Jergović Željka Peršurić Lara Saftić Sandra Kraljević Pavelić 《Journal of the American Oil Chemists' Society》2017,94(6):749-757
Adulteration of extra virgin olive oil (EVOO) by addition of other vegetable oils or lower-grade olive oils is a common problem of the oil market worldwide. Therefore, we developed a fast protocol for detection of EVOO adulteration by mass spectrometry fingerprinting of triacylglycerol (TAG) profiles based on MALDI-TOF/MS. For that purpose, EVOO TAG profiles were compared with those of edible sunflower oil and olive oil composed of refined olive oil and virgin olive oils. Adulteration of EVOO was simulated by addition of sunflower and mixture of refined olive oil and virgin olive oils at 1, 10 and 20% w/w. Results of mass spectrometry TAG profiling were compared with routinely assessed K values for identification of adulteration. MALDI-TOF/MS technology coupled with statistical analysis was proven as useful for detection of adulteration in EVOO at a rate down to 1%. In contrast, standard spectrophotometric methods failed to identify minor adulterations. In addition, the ability of MALDI-TOF/MS in detection of adulteration was tested on EVOO samples from different geographical regions. Results demonstrated that MALDI-TOF/MS technology coupled with statistical analysis is able to distinguish adulterated oils from other EVOO. 相似文献
994.
Dragan J. Cvetković Mihajlo Z. Stanković Milorad D. Cakić Saša R. Savić Marko D. Miljković 《分离科学与技术》2017,52(6):1039-1051
Antioxidant activity of aqueous extracts from two cultivated strawberry leaves, Senga Sengana and Mount Everest, obtained by maceration, reflux extraction and ultrasonic extraction, was investigated. Antioxidant activity of extracts was assessed by DPPH, FRAP, FIC and H2O2 test; total phenolics and flavonoids were assessed by Folin–Ciocalteu and aluminium chloride methods, respectively. Extract obtained from Senga Sengana by reflux extraction, containing higher amounts of extractive matter, total phenolics and flavonoids, has shown higher antioxidant activity (EC50(DPPH) = 10.4 μg/mL; FRAP = 258.61 mgFe2+/g dry extract.; FIC activity = 62.6% in concentration of 2 mg/mL; H2O2 scavenging = 25.43% in concentration of 0.5 mg/mL) compared to extracts obtained by other extraction techniques. Rutin, coumaroyl-galloyl-glucopyranoside, hydroxyphenylethyl-coumaroyl-glucopyranoside, derivates of hydroxyphenylethyl-coumaroyl-glucopyranoside, chlorogenic acid and p-coumaroylhexose have been identified by UHPLC–DAD–HESI–MS analysis. 相似文献
995.
An aqueous two-phase system (ATPS) in combination with macro- and micro-extractors was used for polyphenol extraction from a model solution (gallic acid) and three real samples (red and white wine, and orange juice). The objective of the present study was to apply a mathematical model that successfully describes and predicts performances of macro- and micro-extractors. The micro-extractor system was selected as the most suitable for the polyphenol extraction because the same extraction efficiency was obtained for two levels of magnitude shorter residence time compared to the macro-extractor. Based on good agreement between model predictions and experimental results, the obtained simulations could be used for further process optimization and improvement. 相似文献
996.
Liquid–liquid equilibrium for eight ternary systems involving one hydrocarbon (n-hexane, n-heptane, i-octane or toluene), thiophene or pyridine and an ionic liquid (1-hexyl-3,5-dimethylpyridinium bis(trifluoromethylsulfonyl)imide) was experimentally determined at atmospheric pressure and 25°C. Equilibrium data are presented with binodal curves as well as with tie lines. The suitability of ionic liquid (IL) for extractive desulfurization and denitrification was evaluated in terms of solute distribution ratio and selectivity. Extraction experiments with three-component and seven-component (n-hexane, n-heptane, i-octane, toluene, thiophene, pyridine and IL) systems have been performed. The equilibrium data in three-component systems were well described with Non-Random Two-Liquid (NRTL) and Universal Quasi-Chemical (UNIQUAC) models. 相似文献
997.
A method of describing and analyzing the stochastic process of droughts, which are defined here as the upper extremes of intervals of no rainfall, is recommended. All important components of extreme dry weather intervals such as their duration, time of occurrence, their total number in a given time interval [0, t], the longest drought duration in a given time interval [0, t], and time T(t) of occurrence of the longest drought are taken into consideration. Application of the method is performed using the records of nine meteorological stations in Baka, Yugoslavia and a good agreement is found between the theoretical and empirical distribution functions for all analyzed components of the process. On the basis of the performed computations, a set of maps showing the contours of extreme dry weather intervals, having return periods from 2, 5... up to 100 years, related to the growing season (1 April –30 September), for the region of Baka in Yugoslavia is obtained. If the period of exploitation of an irrigation system is 60 years, then it could be expected to appear as 20 dry weather intervals having 3 year return periods. The duration of dry weather intervals is given on the set of maps. The obtained results give a prognosis of an average state of droughts during long time intervals (60, 100, 200... years). 相似文献
998.
Chemical and structural properties of oxide precipitates formed from FeSO4 solution were investigated using X-ray diffraction and57Fe Mössbauer spectroscopy. The hydrolysis of urea at elevated temperature was used for the generation of OH– ions during the precipitation process. The formation of particular oxide phase in the precipitate is strongly dependent on the concentrations of FeSO4 and urea, as well as on the rate of oxygenation. The phase analysis of precipitates showed the presence of different oxide phases, such as goethite, lepidocrocite, hematite and magnetite, and in one sample of a small amount of siderite. Only substoichiometric magnetite, Fe3–x
O4, was detected. Significant differences in the Mössbauer spectrum of goethite were observed, due to a very small particle size, the degree of crystallinity and/or different content of structurally bonded water. The correlation between the Mössbauer spectra of precipitated goethite and goethite formed during the atmospheric corrosion of steel is discussed. 相似文献
999.
Using Newton's corrections and Gauss-Seidel approach, a modification of single-step method [1] for the simultaneous finding all zeros of ann-th degree polynomial is formulated in this paper. It is shown thatR-order of convergence of the presented method is at least 2(1+τ n ) where τ n ∈(1,2) is the unique positive zero of the polynomial \(\tilde f_n (\tau ) = \tau ^n - \tau - 1\) . Faster convergence of the modified method in reference to the similar methods is attained without additional calculations. Comparison is performed in the example of an algebraic equation. 相似文献
1000.