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We analyze the properties of probabilistic reversible decide-and-halt automata (DH-PRA) and show that there is a strong relationship between DH-PRA and 1-way quantum automata. We show that a general class of regular languages is not recognizable by DH-PRA by proving that two “forbidden” constructions in minimal deterministic automata correspond to languages not recognizable by DH-PRA. The shown class is identical to a class known to be not recognizable by 1-way quantum automata. We also prove that the class of languages recognizable by DH-PRA is not closed under union and other non-trivial Boolean operations. 相似文献
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Comparative characterization of particle emissions from asbestos and non-asbestos cement roof slates
Prasauskas Tadas Martuzevicius Dainius Krugly Edvinas Kliucininkas Linas Kireitseu Maksim Zerrath Axel 《Building and Environment》2011
The first aim of this study was to characterise total and size-fractionated particulate matter (PM) aerosol, including fibres, released from the processing operations of cement roofing slates. The second aim was to compare particle emissions from asbestos-cement and non-asbestos cement sheets, with respect to total and size-fractionated particulate matter as well as fibres emissions. Asbestos and cellulose-based cement sheets were compared during slate treatment processes, namely crushing, rubbing, rasping and scrubbing. Generated PM and fibres were classified by a variety of methods (PM2.5 and PM10 cyclones, aerodynamic particle spectrometer and optical particle counter). A substantial variation in the mass of generated particles has been noticed, both within each PM fraction and between different treatment processes. The PM10/PMtotal concentration ratio ranged from 70 to 98% and PM2.5/PMtotal ratio equalled to ∼20%. The new generation non-asbestos sheets produced three times higher PM emissions than asbestos-cement sheets during crushing operation. Particle size distribution of number concentrations was mostly bimodal (two modes at 0.5 and 2.5 μm). With respect to fibres, the release of cellulose fibres from non-asbestos slates was from 1.8 to 13 times lower in comparison with asbestos fibres. At the same time, cellulose fibre length was 1.4–1.6 times lower. Hence, new generation non-asbestos roofing slates were proved to be less hazardous from the point of view of fibre release, but more hazardous with respect to total particle release. 相似文献
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The aim of the current study was to investigate the effect of oxidation on abrasive wear behaviour of TiC based cermets at temperatures ranging from 20 to 900 °C. Three types of material performance maps were constructed: oxidation rate maps, wear rate maps and maps showing the effect of oxidation on abrasion. Discussion on the performance of different cermet grades is supported by the SEM images combined with EDS and XRD analysis. The results should facilitate the selection of TiC-based cermets providing optimum composition of cermets for high temperature applications. 相似文献
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Juras Banys Saulius Rudys Maksim Ivanov Jing Li Hong Wang 《Journal of the European Ceramic Society》2010,30(2):385-388
In this work dielectric properties of Bi1.5Zn1?xLixNb1.5O7?xFx with x = 0.25 were investigated in a 20 Hz–12 GHz frequency and 120–500 K temperature range and compared to that of regular cubic BZN (when x = 0). Measurements showed that both ceramics have dipolar glass type dielectric dispersion with wide relaxation time distributions. Mean relaxation time follows Arrhenius law in the investigated frequency range, although Vogel–Fulcher law was anticipated. 相似文献
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The subsurface developed in ceramic-metal composites WC-Co, TiC-NiMo and Cr3C2-Ni during tribological testing (abrasion, sliding, erosion) under different conditions (impact angle, velocity, pressure, temperature) is the primary concern of the study. Mechanisms responsible for mechanically mixed layer (MML) development and wear resistance of materials are discussed in details. Instrumented indentation combined with consecutive polishing-testing procedure was used for mechanical characterisation. Microstructural features of the worn surface and subsurface region were studied with the help of optical microscope and scanning electron microscope equipped with energy dispersive spectroscopy analyser to evaluate difference between properties of the bulk and modified subsurface layers of materials.Formation of subsurface layer is found to be an essential feature of materials response to applied loading. Modified layer consists of highly deformed binder metal; cracked and decohesed large grains of carbides; embedded and/or fused debris of erosive/abrasive particles; and products of oxidation. 相似文献
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Dr. Taha Bilal Uyar Dr. Kui Wu Muhan He Dr. Irfan Khan Prof. Maksim Royzen Prof. Mehmet V. Yigit 《ChemMedChem》2020,15(11):988-994
Monitoring the release and activation of prodrug formulations provides essential information about the outcome of a therapy. While the prodrug delivery can be confirmed by using different imaging techniques, confirming the release of active payload by using imaging is a challenge. Here, we have discovered that the switchable fluorescence of doxorubicin can validate drug release upon its uncaging reaction with a highly specific chemical partner. We have observed that the conjugation of doxorubicin with a trans-cyclooctene (TCO) diminishes its fluorescence at 595 nm. This quenched fluorescence of the doxorubicin prodrug is recovered upon its bond-cleaving reaction with tetrazine. Clinically assessed iron oxide nanoparticles were used to formulate a doxorubicin nanodrug. The release of doxorubicin from the nanodrug was studied under various experimental conditions. A fivefold increase in doxorubicin fluorescence is observed after complete release. The studies were carried out in vitro in MDA-MB-231 breast cancer cells. An increase in Dox signal was observed upon tetrazine administration. This switchable fluorescence mechanism of Dox could be employed for fundamental studies, that is, the reactivity of various tetrazine and TCO linker types under different experimental conditions. In addition, the system could be instrumental for translational research where the release and activation of doxorubicin prodrug payloads can be monitored by using optical imaging systems. 相似文献