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排序方式: 共有5203条查询结果,搜索用时 187 毫秒
1.
Fabiana D'Isanto Federico Smeacetto Hans-Peter Martin Richard Sedlák Maksym Lisnichuk Andreas Chrysanthou Milena Salvo 《Ceramics International》2021,47(14):19774-19783
A silica-based glass-ceramic, with Y2Ti2O7 as the major crystalline phase, is designed, characterised and tested as an oxidation-protective coating for a titanium suboxide (TiOx) thermoelectric material at temperatures of up to 600 °C. The optimised sinter-crystallisation treatment temperatures are found to be 1300 °C and 855 °C for a duration of 30 min, and this treatment leads to a glass-ceramic with cubic Y2Ti2O7 and CaAl2Si2O8 as crystalline phases. An increase of ~270 °C in the dilatometric softening temperature is observed after devitrification of the parent glass, thus further extending its working temperature range.Excellent adhesion of the glass-ceramic coating to the thermoelectric material is maintained after exposure to a temperature of 600 °C for 120 h under oxidising conditions, thus confirming the effectiveness of the T1 glass-ceramic in protecting the TiOx material. 相似文献
2.
Journal of Low Temperature Physics - This study modeled and investigated the magnetocaloric effect in Ni2MnGa Heusler alloy characterized by its magnetic entropy change (ΔSm) and its... 相似文献
3.
Marcus Reppich Zdeněk Jegla Jakob Grondinger Yaovi Ouézou Azouma Vojtěch Turek 《化学,工程师,技术》2021,93(10):1581-1589
This study investigates the behavior of fruit and vegetable samples during drying. The experimental data are fitted to several different thin-layer drying models. Regression analysis is used to determine model parameters, while statistical indicators serve to evaluate the goodness of fit. The power function model gives the best fit for all examined samples. Based on this model, different drying and heat storage technologies can be combined to ensure that the required residual moisture content of an agricultural product is reached. It is demonstrated on the case of a specific Togolese processing plant that under favorable conditions, fossil fuel consumption can be decreased by 33 %. 相似文献
4.
Prof. Andrea Baier Dr. Anne Kokel Dr. William Horton Ewa Gizińska Dr. Garima Pandey Prof. Ryszard Szyszka Prof. Béla Török Prof. Marianna Török 《ChemMedChem》2021,16(12):1927-1932
A set of novel hydrazone derivatives were synthesized and analyzed for their biological activities. The compounds were tested for their inhibitory effect on the phosphorylating activity of the protein kinase CK2, and their antioxidant activity was also determined in three commonly used assays. The hydrazones were evaluated for their radical scavenging against the DPPH, ABTS and peroxyl radicals. Several compounds have been identified as good antioxidants as well as potent protein kinase CK2 inhibitors. Most hydrazones containing a 4-N(CH3)2 residue or perfluorinated phenyl rings showed high activity in the radical-scavenging assays and possess nanomolar IC50 values in the kinase assays. 相似文献
5.
Golam Haider Krishna Sampathkumar Tim Verhagen Lukáš Nádvorník Farjana J. Sonia Václav Valeš Jan Sýkora Peter Kapusta Petr Němec Martin Hof Otakar Frank Yang-Fang Chen Jana Vejpravová Martin Kalbáč 《Advanced functional materials》2021,31(29):2102196
Recent advancements in isolation and stacking of layered van der Waals materials have created an unprecedented paradigm for demonstrating varieties of 2D quantum materials. Rationally designed van der Waals heterostructures composed of monolayer transition-metal dichalcogenides (TMDs) and few-layer hBN show several unique optoelectronic features driven by correlations. However, entangled superradiant excitonic species in such systems have not been observed before. In this report, it is demonstrated that strong suppression of phonon population at low temperature results in a formation of a coherent excitonic-dipoles ensemble in the heterostructure, and the collective oscillation of those dipoles stimulates a robust phase synchronized ultra-narrow band superradiant emission even at extremely low pumping intensity. Such emitters are in high demand for a multitude of applications, including fundamental research on many-body correlations and other state-of-the-art technologies. This timely demonstration paves the way for further exploration of ultralow-threshold quantum-emitting devices with unmatched design freedom and spectral tunability. 相似文献
6.
Ondrej Hanzel Meinam Annebushan Singh Deepak Marla Richard Sedlák Pavol Šajgalík 《Journal of the European Ceramic Society》2019,39(8):2626-2633
SiC based composites filled with graphene nano-platelets (GNPs) or graphene oxide (GO) prepared by rapid hot-pressing exhibit sufficient electrical conductivity for their machinability by wire electro-discharge machining (WEDM). Composites microstructure anisotropy caused by graphene alignment as a consequence of rapid hot pressing was confirmed by measuring of electrical conductivity and thermal diffusivity. Electrical conductivity increased significantly with increased weight fraction of graphene in both measured directions. Highest value of 2031 S/m was obtained for composites with 15 wt. % of GNPs in parallel direction and only 1246 S/m in perpendicular direction to aligned GNPs. Thermal diffusivity is 63.3 mm2/s in parallel and only 23.3 mm2/s in perpendicular direction. The increase of the electrical conductivity has resulted in successful WEDM. The MRR was almost doubled when the filler concentration increased from 5 wt. % GNPs/GO to 15 wt. % GNPs. At the same time, the surface roughness decreased. 相似文献
7.
Gülsün Özyurt Ali Serhat Özkütük Yılmaz Uçar Mustafa Durmuş Yesim Ozogul 《International Journal of Food Science & Technology》2019,54(4):1081-1088
Waste or by-products contains a substantial amount of nutrients. Fish silage is an alternative way for assessment of fish discards and waste generated in the fish processing industries. The aim of the study was to evaluate the potential use of discard species (Equulites klunzingeri, marine fish and Carassius gibelio, freshwater fish) for fish silage and chemical quality of fish oil extracted from fish silages prepared with acid and fermented methods. Lipid quality of fish oils extracted from fish silages with LAB strains was evaluated in terms of thiobarbituric acid (TBA), peroxide value (PV), p-Anisidine (AV), totox values and fatty acid composition. The results showed that PV, TBA, AV and totox values of all extracted fish oils were within the acceptable limits for edible oils. Recovered fish oils from silage contained high level of polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), serving as a source of good quality fish oil for human consumption. 相似文献
8.
Lucie Vitejnov Vclav Lika Arvind Kumar Jana Ke
kov Ondej Vy
ítal Jan Brha Jan Bene Yaroslav Kolinko Tereza Blassov Zbynk Tonar Michaela Brychtov Marie Karlíkov Jaroslav Racek Hynek Mírka Petr Hoek Daniel Lysk Milena Krlí
kov 《International journal of molecular sciences》2021,22(9)
In liver surgery, biliary obstruction can lead to secondary biliary cirrhosis, a life-threatening disease with liver transplantation as the only curative treatment option. Mesenchymal stromal cells (MSC) have been shown to improve liver function in both acute and chronic liver disease models. This study evaluated the effect of allogenic MSC transplantation in a large animal model of repeated biliary obstruction followed by partial hepatectomy. MSC transplantation supported the growth of regenerated liver tissue after 14 days (MSC group, n = 10: from 1087 ± 108 (0 h) to 1243 ± 92 mL (14 days); control group, n = 11: from 1080 ± 95 (0 h) to 1100 ± 105 mL (14 days), p = 0.016), with a lower volume fraction of hepatocytes in regenerated liver tissue compared to resected liver tissue (59.5 ± 10.2% vs. 70.2 ± 5.6%, p < 0.05). Volume fraction of connective tissue, blood vessels and bile vessels in regenerated liver tissue, serum levels of liver enzymes (AST, ALT, ALP and GGT) and liver metabolites (albumin, bilirubin, urea and creatinine), as well as plasma levels of IL-6, IL-8, TNF-α and TGF-β, were not affected by MSC transplantation. In our novel, large animal (pig) model of repeated biliary obstruction followed by partial hepatectomy, MSC transplantation promoted growth of liver tissue without any effect on liver function. This study underscores the importance of translating results between small and large animal models as well as the careful translation of results from animal model into human medicine. 相似文献
9.
Al-xNi-yCeO2 (x = 6, 10, 15, 20 and y = 0, 5, 10 wt%) composites were produced by a powder metallurgical production route. Powder mixtures of Al, Ni and CeO2 were fabricated via mechanical alloying (MA) for 4 h in a Spex-type high-energy ball mill. Both the mechanically alloyed (MAed) and non-MAed (as-blended mixtures) powders were pre-compacted in a hydraulic press under 650 MPa and then pressurelessly consolidated at 630 °C for 2 h under an inert atmosphere. The effects of MA process and the amounts of Ni and CeO2 on the microstructural, mechanical and tribological properties of the sintered composites were determined. Based on the SEM and XRD investigations, the MAed powders illustrated a homogenous structure, comprising flaky particles with smaller crystallite sizes and greater lattice strain. According to the XRD analysis, Ni formed Al–Ni intermetallic compounds in the matrix of sintered composites that act as secondary reinforcement phases. The SEM observations conducted on the MAed samples demonstrated more uniformly and finely distributed Al3Ni and CeO2 phases in the microstructure of the MAed samples, unlike the non-MAed ones. The hardness values of sintered composites increased due to the MA process and increasing Ni and CeO2 amounts, and the hardness value of the MAed Al20Ni–10CeO2 sample reached 179 HV. The ultimate compressive strength and failure strain of the MAed Al6Ni–10CeO2 sample were 441 MPa and 11.3%. In the Al20Ni–10CeO2 sample, the compressive strength and failure strain were 391 MPa and 5.5%, respectively. Additionally, the reciprocating wear test results illustrated that both wear resistance and hardness values of the composites increased as the amounts of Ni and CeO2 increased, and the Al20Ni–10CeO2 sample exhibited the highest wear resistance as 0.175 × 10-3 mm3/Nm. 相似文献
10.
In this study, the relationship between stunning techniques and protein oxidation which are accepted as the main cause of food spoilage was investigated. For this purpose, the antioxidant status, in vivo myofibrillary protein (MP) oxidation and sensitivity, and postmortem oxidation (inducted with hydroxyl radical system) of rainbow trout (Oncorhynchus mykiss) fillets killed by hitting to head (T1), neck crushing (T2), and convulsion (T3) methods, were investigated. Statistically significant differences (p < .05) were found among all parameters examined and it was observed that the most stressing technique was the convulsion method. It was determined that in protein profiles myosin were influenced too much from stunning technique and in actin observed oxidation-induced reductions. Reductions in S-S and S-H were also found to be increased in carbonyl concentrations, but the most effective values in both processes were determined by the convulsive technique. Our results show that short-term stunning techniques (hitting to head, neck crushing) give better meat quality results in terms of O. mykiss welfare and low MP oxidation rates. In general, we can say that T3 group fillets are more sensitive to oxidative damage, while T1 and T2 groups give better results in maintaining meat quality with low MP oxidation rates. 相似文献