作者:
Yoo, Jung-WooChen, Chia-YiJang, H. W.bark, C. W.Prigodin, V. N.Eom, C. b.Epstein, A. J.Department of Physics
The Ohio State University Columbus Ohio 43210-1117 USAJung-Woo YooV. N. Prigodin &A. J. EpsteinDepartment of Chemistry The Ohio State University Columbus Ohio 43210-1173 USAJung-Woo Yoo &A. J. EpsteinChemical Physics Program The Ohio State University Columbus Ohio 43210-1106 USAChia-Yi ChenDepartment of Materials Science and Engineering University of Wisconsin–Madison Madison Wisconsin 53706-1595 USAH. W. JangC. W. Bark &C. B. Eom
An important component of spintronics devices is the magnetic electrode, which is usually made from an inorganic alloy. However, an organic-based spin polarizer is now demonstrated, opening new possibilities for devel...
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An important component of spintronics devices is the magnetic electrode, which is usually made from an inorganic alloy. However, an organic-based spin polarizer is now demonstrated, opening new possibilities for developing organic/inorganic hybrid spintronics devices.
It is common for small tandem peptide multimer genes to be indirectly inserted into expression vectors and fused with a protein tag. In this study, a multimer of the tandem angiotensin I-converting enzyme inhibitory p...
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Microwave plasma chemical vapor deposition was used to fabricate nanodiamond films. Nitrogen incorporation was achieved by the introduction of N2 gas along with H2 and CH4 gases in the plasma. SEM studies revealed a c...
Microwave plasma chemical vapor deposition was used to fabricate nanodiamond films. Nitrogen incorporation was achieved by the introduction of N2 gas along with H2 and CH4 gases in the plasma. SEM studies revealed a change in the microstructure with increase in the N2 flow rate, transitioning from a 'ridge'-like surface morphology to a more 'cauliflower'-like structure. X-ray photoelectron spectroscopy (XPS) analysis showed a general decrease in the sp3 hybridized carbon content while the sp2 hybridized carbon content increased with N2 flow rate (up to 28.7%) after which it declines. Deconvolution of the C1s XPS spectra indicates incorporation of nitrogen and existence of carbon-nitrogen bonding. Raman spectroscopy shows diamond peak at 1332 cm-1 and the graphite peak, which increases in intensity and shifts towards lower wave number with increase in the N2 flow rate. A diffuse band at 1140 cm-1 indicates presence of a nanocrystalline phase in the films.
In order for solid state lighting technology to become a mainstream technology, one of the major challenges to overcome is increasing the efficiency of these devices while maintaining a proper color balance. A signifi...
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It has recently been demonstrated that porous β-Si3N 4 can be engineered to provide similar mechanical properties to dense β-Si3N4, with the additional benefits of reduced mass. Porous p-Si3N4 applications could pot...
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ISBN:
(纸本)9780470196403
It has recently been demonstrated that porous β-Si3N 4 can be engineered to provide similar mechanical properties to dense β-Si3N4, with the additional benefits of reduced mass. Porous p-Si3N4 applications could potentially include filtration media, thermal shock resistant components and high-strength, lightweight structural components. Prior work in Japan has shown that flexural strengths exceeding 1 GPa can be achieved by tailoring the microstructure of the β-Si3N4 grains, such that moderately high aspect ratios are obtained after sintering (up to 10:1) with considerable anisotropic grain alignment, while maintaining porosity levels of ∼10-15 %. In the present study, β-Si3N4 ceramics containing higher porosity levels are generated via pressureless sintering in a nitrogen atmosphere, with the addition of single rare earth oxide sintering aids. The oxide additives have been chosen from both the lanthanide (La, Nd, Sm, Yb) and Group IIIb (Y) elements. In each case, the compositions were milled for 24 hours, cold isostatically pressed and then sintered in nitrogen (0.1 MPa) at temperatures ranging from 1500 to 1750°C. Post sinter microstructural characterization was performed using scanning electron microscopy and x-ray diffraction. It is noted that densification and phase transformation kinetics are both strongly influenced by the oxide chosen.
Porous β-Si3N4 can be microstructurally engineered to provide similar mechanical properties to dense β-Si 3N4 with the additional benefits of reduced mass. However, while flexural strengths exceeding 1 GPa can be ac...
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ISBN:
(纸本)9780470196403
Porous β-Si3N4 can be microstructurally engineered to provide similar mechanical properties to dense β-Si 3N4 with the additional benefits of reduced mass. However, while flexural strengths exceeding 1 GPa can be achieved by tailoring the microstructure of the material, through alignment of anisotropic β-Si 3N4 grains, the porosity levels of such materials are still relatively low (3N4 structure (ideally 20-40 vol. % porosity) with high grain aspect ratios (i.e. >10:1). This approach makes use of a low volume fraction of multiple sintering aids, where each additive plays one or more roles in the sintering behavior of Si3N4 (i.e. densification aid, transformation aid and/or whisker growth aid). Compositions are based on various ratios of Y2O3:MgO, both with and without CaO additions. Sintering has been conducted in a nitrogen atmosphere (0.1 MPa) between 1400 and 1700°C. The effects of processing parameters (e.g. composition, sintering temperature and time) will be discussed, paying particular attention to microstructure development, including both the densification behavior and α- to β-Si3N4 transformation kinetics.
We investigate evaporative lithography as a route for patterning colloidal films. Films are dried beneath a mask that induces periodic variations between regions of free and hindered evaporation. Direct imaging reveal...
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We investigate evaporative lithography as a route for patterning colloidal films. Films are dried beneath a mask that induces periodic variations between regions of free and hindered evaporation. Direct imaging reveals that particles segregate laterally within the film, as fluid and entrained particles migrate towards regions of higher evaporative flux. The films exhibit remarkable pattern formation that can be regulated by tuning the initial suspension composition, separation distance between the mask and underlying film, and mask geometry.
Magnesium castings are experiencing increased use in the transportation industry because of their high strength to weight ratio, high stiffness, and excellent castability. The casting characteristics allow complicated...
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