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排序方式: 共有3521条查询结果,搜索用时 546 毫秒
121.
Mikołaj Bojańczyk 《Theory of Computing Systems》2013,53(2):194-222
We develop an algebraic theory for languages of data words. We prove that, under certain conditions, a language of data words is definable in first-order logic if and only if its syntactic monoid is aperiodic. 相似文献
122.
Paweł Piszcz Magdalena Woźniak Monika Asztemborska Bronisław K. Głód 《Food Analytical Methods》2014,7(7):1474-1480
The present investigation reports on the application of a new antioxidant activity assay for the examination of flavonoids. It has been shown that the high-performance liquid chromatography with electrochemical detection (HPLC–ED) measurements allow to obtain additional information about the antioxidative properties of pure compounds by measuring their half-wave potential, the chromatographic peak height, and the product of the peak height and exponent of potential. In comparison to the classical electrochemical measurements, the HPLC–ED is characterized by a much smaller detection limit. The results were compared with the standard photometric measurement based on 1,1-diphenyl-2-picrylhydrazyl radicals. The possible antioxidant activity forecasting is also discussed. 相似文献
123.
Lipp Natalia Dużmańska-Misiarczyk Natalia Strojny Agnieszka Strojny Paweł 《Virtual Reality》2021,25(2):279-292
Virtual Reality - Virtual reality can be used for educational purposes, particularly in demanding professions such as firefighting. Such virtual training may be useful for preparing trainees for... 相似文献
124.
Maj Justyna Węglewski Witold Bochenek Kamil Rogal Łukasz Woźniacka Stefania Basista Michał 《Metallurgical and Materials Transactions A》2021,52(11):4727-4736
Squeeze casting and powder metallurgy techniques were employed to fabricate AlSi12/Al2O3 composites, which are lightweight structural materials with potential applications in the automotive industry. The impact of the processing route on the material properties was studied. Comparative analyses were conducted for the Vickers hardness, flexural strength, fracture toughness, thermal conductivity, thermal residual stresses, and frictional wear. Our results show that the squeeze cast composite exhibits superior properties to those obtained using powder metallurgy.
相似文献125.
Anna Maria Białostocka Urszula Klekotka Beata Kalska-Szostko 《Chemical Engineering Communications》2019,206(6):804-814
In this article, characterization of FeNi layers deposited on a Cu plate for variable magnetic field arrangement is shown. Layers were prepared using a simple electrodeposition process, from an aqueous solution of Fe2+ and Ni2+ sulfate salts containing boric acid, an iron activator. By application of variation of current values, times, and external magnetic field orientations, the resultant film quality was examined and the efficiency of the embedded elements was investigated. The studies show differences in the coating morphology and relative composition of ferromagnetic metals (Ni, Fe) electrodeposited on a not ferromagnetic (paramagnetic) metal (Cu). The obtained layers were investigated by Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy. 相似文献
126.
Tomasz Piechowiak Piotr Antos Radosław Józefczyk Patryk Kosowski Karol Skrobacz 《臭氧:科学与工程》2019,41(4):376-385
In the studies conducted, the impact of the innovative ozonation procedure on the microbial state and antioxidant potential of highbush blueberry (Vaccinum corymbosum L.) stored under cold storage conditions was assessed. Microbiological analysis was carried out to determine the total number of mesophilic aerobic bacteria and the total number of fungi during the storage experiment. In addition, changes in the flavonoid, anthocyanins, and vitamin C content and the total antioxidant capacity were monitored during the storage. The degree of fruit infection with gray mold and anthracnose was determined. It was found that daily ozonation of fruits with a dose of 15 ppm for 30 min, every 12 h, for 28 days effectively reduced the development of aerobic mesophilic bacteria and fungi. On the last day of storage, symptoms of the infection by gray mold were observed in 27.5% of the control fruit, while the absence of symptoms was observed in case of the ozonated fruit. On the other hand, ozone was ineffective in case of inhibiting the infection by anthracnose. Nevertheless, the ozonation process allowed maintaining a high antioxidant potential of the fruit and substantially reduced losses of flavonoids, anthocyanins, and vitamin C. The utilized procedure has proved to be effective, providing the possibility of extensive use of ozone as a factor allowing sustaining a high commercial and consumption value of the fruit over extended time. 相似文献
127.
Joanna Kałużna-Czaplińska Paulina Gątarek Salvatore Chirumbolo Max Stanley Chartrand Geir Bjørklund 《Critical reviews in food science and nutrition》2019,59(1):72-88
Tryptophan (Trp) is an amino acid and an essential component of the human diet. It plays a crucial role in many metabolic functions. Clinicians can use Trp levels in the course of diagnosing various metabolic disorders and the symptoms associated with those diseases. Furthermore, supplementation with this amino acid is considered in the treatment of depression and sleep disorders, mainly due to the Trp relationship with the synthesis of serotonin (5-HT) and melatonin. It is also used in helping to resolve cognitive disorders, anxiety, or neurodegenerative diseases. Reduced secretion of serotonin is associated with autism spectrum disorder, obesity, anorexia and bulimia nervosa, and other diseases presenting peripherals symptoms. The literature strongly suggests that Trp has a significant role in the correct functionality of the brain-gut axis and immunology. This information leads to the consideration of Trp as an essential dietary component due to its role in the serotonin pathway. A reduced availability of Trp in diet and nutraceutical supplementation should be considered with greater concern than one might expect. This paper constitutes a review of the more salient aspects gleaned from the current knowledge base about the role of Trp in diseases, associated nutritional disorders, and food science, in general. 相似文献
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130.
In this work, we aim at quantifying quantum channel output similarity. In order to achieve this, we introduce the notion of quantum channel superfidelity, which gives us an upper bound on the quantum channel fidelity. This quantity is expressed in a clear form using the Kraus representation of a quantum channel. As examples, we show potential applications of this quantity in the quantum control field. 相似文献