Biodegradable magnesium(Mg)has garnered attention for its use in orthopaedic implants due to mechanical properties that closely match to those of *** have been undertaken to understand the corrosion behaviour of these...
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Biodegradable magnesium(Mg)has garnered attention for its use in orthopaedic implants due to mechanical properties that closely match to those of *** have been undertaken to understand the corrosion behaviour of these materials and their effects on bone forming ***,there is lack of research on how the corrosion of these biomaterials affect surrounding tissues such as skeletal *** plays an important role in the structural and functional properties of skeletal *** is therefore important to investigate the response of skeletal muscle cells to both soluble(Mg ions)and insoluble(corrosion granules)corrosion *** in vitro studies it is possible to observe the effects of corrosion products on myotube formation by the fusion of single muscle precursor cells known as *** achieve this goal,it is important to determine if these corrosion products are toxic to *** it was noted that although there was a slight decrement in cellular viability after initial exposure,this soon recovered to control levels.A high Ca/Mg ratio resulted in the formation of large myotubes and a low Ca/Mg ratio negatively affected myotube ***^2+and Ca^2+ions are important in the process of myogenesis,and the concentration of these ions and the ratio of the ions to each other played a significant role in myotube cellular *** outcomes of this study could pave the way to a bio-informed and integrated approach to the design and engineering of Mg-based orthopaedic implants.
The groups of phosphorus-containing brazing alloys are the most favored filler metals used for joining copper and copper-base alloys. These brazing alloys are expected to have the optimum corrosion resistance during t...
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The engineering of plant-based precursor for nitrogen doping has become one of the most promising strategies to enhance rate capability of hard carbon materials for sodium-ion batteries;however,the poor rate performan...
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The engineering of plant-based precursor for nitrogen doping has become one of the most promising strategies to enhance rate capability of hard carbon materials for sodium-ion batteries;however,the poor rate performance is mainly caused by lack of pyridine nitrogen,which often tends to escape because of high temperature in preparation process of hard *** this paper,a high-rate kapok fiber-derived hard carbon is fabricated by cross-linking carboxyl group in 2,6-pyridinedicarboxylic acid with the exposed hydroxyl group on alkalized kapok with assistance of zinc ***,a high nitrogen doping content of 4.24%is achieved,most of which are pyridine nitrogen;this is crucial for improving the defect sites and electronic conductivity of hard *** optimized carbon with feature of high nitrogen content,abundant functional groups,degree of disorder,and large layer spacing exhibits high capacity of 401.7 mAh g^(−1)at a current density of 0.05 A g^(−1),and more importantly,good rate performance,for example,even at the current density of 2 A g^(−1),a specific capacity of 159.5 mAh g^(−1)can be *** findings make plant-based hard carbon a promising candidate for commercial application of sodium-ion batteries,achieving high-rate performance with the enhanced pre-cross-linking interaction between plant precursors and dopants to optimize aromatization process by auxiliary pyrolysis.
Dual pulse gas metal arc welding (DP-GMAW) is a superior welding process where the weld quality and strength of weldment is highly dependent on weld input parameters. It is important to understand the effect of differ...
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The local grain boundary curvature in a model Ni-based superalloy was measured experimentally using Dehoff s tangent count method. The results show that the curvature parameter, K, which relates the grain size to the ...
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ISBN:
(纸本)9780873396868
The local grain boundary curvature in a model Ni-based superalloy was measured experimentally using Dehoff s tangent count method. The results show that the curvature parameter, K, which relates the grain size to the mean boundary curvature, varies both with the volume fraction of the second-phase particles and the holding time during high-temperature annealing. The values of K obtained from the specimens with high particle volume fractions (up to 24% by volume) are much lower than those reported previously for pure or dilute alloy systems. In addition, K decreases gradually as a result of Zener's pinning when grain growth stagnates. Since the local boundary curvature constitutes the driving force for grain growth, these observations could help to explain grain growth phenomena in heavily pinned systems.
Ionic conductivities of solid CeO2:Y2O3 electrolytes were systematically investigated as a function of dopant concentration and sintering temperatures. The highest lattice conductivity occurred at 6-8% dopant concentr...
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Ionic conductivities of solid CeO2:Y2O3 electrolytes were systematically investigated as a function of dopant concentration and sintering temperatures. The highest lattice conductivity occurred at 6-8% dopant concentration, and maximum grain boundary conductivity was observed at 10% dopant concentration. The sintering temperature was found to have a significant effect on the conductivities of the pellets. The samples sintered at lower temperatures (T&le1400°C) showed higher grain boundary conductivity than those sintered at 1500°C;this was found to be related to size-dependent-impurity segregation and precipitation at grain boundaries. The grain boundary conductivities as related to the microstructure are discussed by adopting different grain boundary models. Solute segregation and oxygen depletion at grain boundaries, which have been suggested to be responsible for the grain boundary resistivities in these samples, were examined by a microanalytical techniques for small-grain-size samples.
V85Ni15(at%)alloy was proposed as a promising candidate for hydrogen separation *** date,investigations of V85Ni15 alloy have concentrated on hydrogen permeation characteristics,and little work has been done on the mi...
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V85Ni15(at%)alloy was proposed as a promising candidate for hydrogen separation *** date,investigations of V85Ni15 alloy have concentrated on hydrogen permeation characteristics,and little work has been done on the microstructural *** the present study,various fabrication and heat-treatment techniques were used to develop different microstructures which would then be tailored to achieve a desired candidate for acceptable mechanical stability while maintaining high hydrogen *** arc-melted(AM)V85Ni15 alloy are supersaturated solid solution with dendritic segregation of Ni-solute *** rolling(CR)followed by annealing at 1050℃and 850℃can produce a two-phase(V+σ)microstructure and a three-phase(V+σ+NiV3)microstructure,*** fine two-phase microstructure obtained at 1050℃involves a simultaneous reaction of second-phase precipitation and V-matrix *** phase is formed via primary precipitation,while NiV3 phase is formed by peritectoidal *** AMCR samples were homogenized at1250℃for 2 h and sequential heat-treated at 850℃or900℃for 2 h,precipitation-strengthening microstructure is obtained:large grain structure of V-matrix with uniform distribution of second-phase particles produced by recrystallization and grain growth followed by precipitation process.
As a protective hard coating on glass molding dies, Mo-Ru coatings were fabricated on binderless tungsten carbide substrates by RF magnetron sputtering. The Mo-Ru deposits were deposited at 550 °C, which revealed...
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Thin films of semiconductor nanocrystals continue to receive attention as potential materials for making light-emitting diodes, photodiodes and solar cells. This approach to making optoelectronic devices may be promis...
ISBN:
(纸本)9781618397294
Thin films of semiconductor nanocrystals continue to receive attention as potential materials for making light-emitting diodes, photodiodes and solar cells. This approach to making optoelectronic devices may be promising because semiconductor nanocrystals are inexpensive to synthesize and their optoelectronic properties can be tuned by changing their size. However, devices based on thin films of nanocrystals typically show high electrical resistivity, and establishing control over electronic properties is difficult. The understanding of electronic transport in these nanocrystal films is in its infancy compared to bulk semiconductors. To improve this understanding and to learn how to manipulate charge carrier transport in semiconductor nanocrystal films, we study electronic transport in thin films of intrinsic and doped silicon nanocrystals. Silicon nanocrystals with diameters ranging from 5-20 nm were synthesized through decomposition of silane in a radio-frequency plasma reactor. Thin films of these nanocrystals were deposited either through ballistic aerosol impaction onto substrates or through spin coating from colloidal dispersions of the nanocrystals. The former approach is in situ and the nanocrystals are deposited onto the substrate immediately after they leave the plasma. In the latter approach, the nanocrystals emerging from the plasma are collected, dispersed in a solvent and cast onto the substrate. In both cases, the nanocrystals are deposited between two 100 nm-thick thermally evaporated aluminum contacts to form thin films of randomly packed nanoparticles. Current-voltage characteristics of the nanocrystal films were measured as a function of doping and temperature between 100 and 300 K. Preliminary results show that the films exhibit space charge limited current above applied electric fields of 1000 V/cm, and Ohmic behavior at lower electric fields. The conductivity of annealed undoped films exhibits Arrhenius dependence on temperature, with an activa
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