The effect of Zr2+ irradiation on microstructure and corrosion in 360 degrees c lithiated water with 0.01 mol/L LiOH was investigated on a 90Nb-10Zr binary alloy prepared by referring to the 8-Nb phase in zirconium al...
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The effect of Zr2+ irradiation on microstructure and corrosion in 360 degrees c lithiated water with 0.01 mol/L LiOH was investigated on a 90Nb-10Zr binary alloy prepared by referring to the 8-Nb phase in zirconium alloys. The results revealed that the irradiation induced a ZrO2 film on the specimen surface and increased dislocations in matrix. After corrosion, oxide scales with a three-layer structure were formed regardless of irradiation. However, the scale formed on the irradiated surface was relatively thin presumably due to the ZrO2 film. A hypothesis for the corrosion mechanism of 8-Nb phase in lithiated water upon irradiation was proposed.
Full-carbon/ceramic brake pairs have been recently proposed to achieve profound applications of c/c-Sic brake materials in brake systems with a high-energy load. Severe wear rate and a high and unstable coefficient of...
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Full-carbon/ceramic brake pairs have been recently proposed to achieve profound applications of c/c-Sic brake materials in brake systems with a high-energy load. Severe wear rate and a high and unstable coefficient of friction (cOF) of the traditional c/c-Sic disc-pads pairs prevented further development of this material. In this study, FeSi75 alloy and cu were mixed to form an infiltration agent to modify the c/c-Siccomposites. We examined the braking performance of the Fe-Si-cu modified c/c-Sic brake pads mated with traditional needled c/c-Sic brake disc using a lab-scale dynamometer. The results revealed that the Fe-Si-cu blending modification yielded a significant wear reduction of the brake disc and pads. After a series of braking tests, the worn surface morphology was characterized, and the wear resistance improvement mechanism was analyzed.
The surface microstructural evolution, mechanical properties and ablation behaviors of nitrogen-doped c/c-ZrcSiccomposites by hot isostatic pressing(HIP) have been studied via multiple-characterizations. Results show...
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The surface microstructural evolution, mechanical properties and ablation behaviors of nitrogen-doped c/c-ZrcSiccomposites by hot isostatic pressing(HIP) have been studied via multiple-characterizations. Results show that the post-treatment of nitridation has significant effects on mechanical strength with grain refinement by virtue of in-situ SEM observations. After nitridation, the dense nano-grained ZrO/Zr2O and Si3N4 ceramics are generated on the top layer. Besides, the evident carbon nanowires exist at boundary of Sic-Si3N4 phases. The ZrN/Si3N4 eutectic structures are also detected with the transformation of ZrSi phase. What's more, the ablation-resistant performances are strikingly improved after nitridation-treatment with the highly compact multi-oxide scales obtained.
The influence of cr and Al content on the oxidation behaviour of Fecr(Al) model alloys after breakaway oxidation at 600 degrees c and the underlying mechanisms were investigated in detail with thermogravimetrical anal...
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The influence of cr and Al content on the oxidation behaviour of Fecr(Al) model alloys after breakaway oxidation at 600 degrees c and the underlying mechanisms were investigated in detail with thermogravimetrical analysis (TGA), thermodynamiccalculations and advanced electron microscopy. The results showed that a crcontent of >18 wt% drastically reduced the growth rate of the Fe-rich oxide scale, formed after breakaway oxidation, for FecrAl alloys but not for Fecr alloys. This was attributed to the ability of the Fe(18-25)crAl alloys to prevent internal oxidation, which enables the formation of a healing layer.
We report here the influence of Mg and Si-doping during growth, on the morphology, structure, and optical properties of single-crystalline GaN nanorods (NRs) grown on Si substrates using plasma-assisted molecular beam...
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We report here the influence of Mg and Si-doping during growth, on the morphology, structure, and optical properties of single-crystalline GaN nanorods (NRs) grown on Si substrates using plasma-assisted molecular beam epitaxy. Mg-doping is shown to enhance the lateral growth of the NRs, leading to a higher degree of coalescence. Si-doping during the nucleation stage of the growth enhances the mutual misorientation of the NRs. Strain profile measurements along the length of individual NR by transmission electron microscopy shows that the top regions are relaxed. Evaluation of carrier concentration by Raman spectroscopy reveals that Si-doping leads to an increase of carrier concentration from 1016 to 1017 cm-3, and the optimal Mg incorporation for the realisation of pdoping is confirmed by photoluminescence spectroscopy. These results will significantly help in understanding and tuning the structural and optical properties of GaN NRs through doping in the fabrication of NR based optoelectronic devices.
The microalga c. vulgaris is a potential source for sustainable food ingredients and particularly food protein. Ultrasonication can enhance the extraction of proteins from chlorella, but a comprehensive comparison to ...
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The microalga c. vulgaris is a potential source for sustainable food ingredients and particularly food protein. Ultrasonication can enhance the extraction of proteins from chlorella, but a comprehensive comparison to other cell disintegration technologies is not possible since knowledge about the energy requirements is missing. In this article, the effects of an elevated static pressure up to 5 bar, sound amplitude, and treatment duration on energy consumption and protein extraction yield were explored. Elevating the static pressure affects the oscillation dynamics and collapses of cavitating bubbles and leads to more destructive collapses and higher energy. By employing numerical simulations of bubble oscillations, it was shown that the protein yield is mostly affected by the energy being radiated during the collapse of single bubbles and the total number of collapses during the treatment. Increasing the biomass concentration before sonication offers a way to further reduce the massspecific energy input.
Fullerene (c-60) single crystals with exceptionally low defects and nearly perfect translational symmetry make them appealing in achieving high-performance n-type organic transistors. However, because of its natural 0...
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Fullerene (c-60) single crystals with exceptionally low defects and nearly perfect translational symmetry make them appealing in achieving high-performance n-type organic transistors. However, because of its natural 0D structure, control over continuous crystallization of c-60 over a large area is extremely challenging. Here, the authors report a solution-phase epitaxial approach for wafer-scale growth of continuously aligned c-60 single crystals. This method enables the rational control of the density of nucleation event at meniscus front by confining the size and shape of meniscus with a microchannel template. In this case, a single nucleus as seed crystal can be formed at the front of meniscus, and then epitaxial growth from the seed crystal occurs with continuous retreat of the meniscus. As a result, highly uniform c-60 single-crystal array with ultralow defect density is obtained on 2-inch substrate. Organic field-effect transistors made from the c-60 single-crystal array show a high average electron mobility of 2.17 cm(2) V-1 s(-1), along with a maximum mobility of 5.09 cm(2) V-1 s(-1), which is much superior to the c-60 polycrystalline film-based devices. This strategy opens new opportunities for the scalable fabrication of high-performance integrated devices based on organiccrystals.
Based on density functional theory calculations under the framework of first-principles, the electronic and optical characteristics of c2N/ZnTe van der Waals (vdW) heterostructure are investigated in detail. An inhere...
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Based on density functional theory calculations under the framework of first-principles, the electronic and optical characteristics of c2N/ZnTe van der Waals (vdW) heterostructure are investigated in detail. An inherent type-II band alignment arises in the heterostructure, which possesses a 1.94 eV direct band gap. With light irradiation, the photogenerated electron-hole pairs of heterostructure are separated on different monolayers. This helps to extending the lifetime of carriers. Additionally, the lower effective carrier mass (me*=0.55m0, mh*=0.23m0) is owned for the heterostructure. The heterostructure has suitable band gap and band edge positions, as well as, enhanced visible light absorption capacity, which can facilitate photocatalytic water splitting in acidicconditions. More interestingly, the redox reaction of photocatalytic water splitting can still proceed on the heterostructure after exerting a biaxial tensile strain of 2-6%. These results suggest that c2N/ZnTe vdW heterostructure will be a promising water splitting photocatalyst.
To operate the moving bed biofilm reactor inoculated with HN-AD bacteria (B-MBBR) instead of activated sludge for livestock and poultry breeding wastewater (LPBW) disposal in most efficient manner, nitrogen removal (N...
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To operate the moving bed biofilm reactor inoculated with HN-AD bacteria (B-MBBR) instead of activated sludge for livestock and poultry breeding wastewater (LPBW) disposal in most efficient manner, nitrogen removal (NR) efficiency and microbial composition of two MBBRs with different carrier types under various c/N ratios were explored. Results indicated that the performance on NR greatly various in different carrier types under various c/ N ratios. Attributing to the bacterial protection provided by the porous structure of polyvinyl alcohol (PVA) gel, MBBR using PVA gel as the carrier exhibited a more stable NR performance (range from 78.05% to 83.76%) versus that using Kaldnes (K1) as the carrier (range from 78.05% to 83.76%). Besides, microbial analysis indicated that MBBR with PVA gel as the carrier is conducive to the growth of oligotrophic and HN-AD bacteria (Paracoccus and Acinetobacter), and the highest relative abundance was 16.37% at c/N ratio of 6.
caenorhabditiselegans (c. elegans) has gained importance as a model for studying host-microbiota interactions and bacterial infections related to human pathogens. Assessing the fate of ingested bacteria in the worm...
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caenorhabditiselegans (c. elegans) has gained importance as a model for studying host-microbiota interactions and bacterial infections related to human pathogens. Assessing the fate of ingested bacteria in the worm's intestine is therefore of great interest, in particular with respect to normal bacterial digestion or intestinal colonization by pathogens. Here, we report an in vivo study of bacteria in the gut of c. elegans. We take advantage of a polydimethylsiloxane (PDMS) microfluidic device enabling passive immobilization of adult worms under physiological conditions. Non-pathogenic Escherichia coli (E. coli) bacteria expressing either pH-sensitive or pH-insensitive fluorescence reporters as well as fluorescently marked indigestible microbeads were used for the different assays. Dynamic fluorescence patterns of the bacterial load in the worm gut were conveniently monitored by time-lapse imaging. cyclic motion of the bacterial load due to peristaltic activity of the gut was observed and biochemical digestion of E. coli was characterized by high-resolution fluorescence imaging of the worm's intestine. We could discriminate between individual intact bacteria and diffuse signals related to disrupted bacteria that can be digested. From the decay of the diffuse fluorescent signal, we determined a digestion time constant of 14 +/- 4 s. In order to evaluate the possibility to perform infection assays with our platform, immobilized c. elegans worms were fed pathogenic Mycobacterium marinum (M. marinum) bacteria. We analyzed bacterial fate and accumulation in the gut of N2 worms and mitochondrial stress response in a hsp-6::gfp mutant.
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