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991.
In this study, a catalytic membrane with controlled pore size and structure was fabricated with nano sized particles and used in a steam and dry reforming reaction. The catalytic membrane was made using uniaxial-pressing and thermal treatment of the mixed powder. Nano sized yttria stabilized ZrO2 added to the nickel powder was determined to be a key factor in the preparation of the catalytic membrane. The membrane did not show the sintering effect due to the hindering of nickel agglomeration when subjected to heat treatment at high temperature. The optimum yttria stabilized ZrO2 content was below 1 wt% due to its strength and porosity. It was also unnecessary to deposit an additional reforming catalyst on the catalytic membrane, since the surface nickel site displayed excellent catalytic activity. When a mixture of methane and water/carbon dioxide was fed into the YSZ-Ni catalytic membrane reactor, the activity trended exceeded the performance of a conventional catalyst reactor, because of the difference in the flux of the gases. 相似文献
992.
Choo DC Bang HS Kim TW Seo JH Kim YK 《Journal of nanoscience and nanotechnology》2012,12(2):1649-1653
The electrical and the optical properties of phosphorescent organic light-emitting devices (PHOLEDs) fabricated utilizing a mixed host emitting layer (EML) consisting of N,N'-dicarbazolyl-3,5-benzene (mCP) and 1,3,5-tri(phenyl-2-benzimidazole)-benzene (TPBi) were investigated to clarify the carrier transport mechanisms of PHOLEDs. While the operating voltage of the PHOLEDs with a mixed host EML significantly decreased due to the insertion of TPBi with a high electron mobility, the quantum efficiency of the PHOLEDs decreased due to the hindrance of the exciton energy transfer by TPBi molecules. The electroluminescence spectra for the PHOLEDs with an tris(2-phenylpyridine)iridium-doped mixed host EML showed that the TPBi molecules in the mixed host EML increased the electron injection into the mixed host EML, resulting in a decrease of the shift length of the recombination zone in comparison with a single host EML. 相似文献
993.
994.
995.
Liu Y Cheng XJ Dang QF Ma FK Chen XG Park HJ Kim BK 《Journal of materials science. Materials in medicine》2012,23(2):375-384
Oleoyl-carboxymethy chitosan (OCMCS) nanoparticles based on chitosan with different molecular weights (50, 170 and 820 kDa)
were prepared by self-assembled method. The nanoparticles had spherical shape, positive surface charges and the mean diameters
were 157.4, 274.1 and 396.7 nm, respectively. FITC-labeled OCMCS nanoparticles were internalized via the intestinal mucosa
and observed in liver, spleen, intestine and heart following oral deliverance to carps (Cyprinus carpio). Extracellular products
(ECPs) of Aeromonas hydrophila as microbial antigen was efficiently loaded to form OCMCS–ECPs nanoparticles and shown to be sustained release in PBS. Significantly
higher (P < 0.05) antigen-specific antibodies were detected in serum after orally immunized with OCMCS-ECPs nanoparticles than that
immunized with ECPs alone and non-immunized in control group in carps. These results implied that amphiphilic modified chitosan
nanoparticles had great potential to be applied as carriers for the oral administration of protein drugs. 相似文献
996.
Kratz K Narasimhan A Tangirala R Moon S Revanur R Kundu S Kim HS Crosby AJ Russell TP Emrick T Kolmakov G Balazs AC 《Nature nanotechnology》2012,7(2):87-90
Nanoparticles have useful properties, but it is often important that they only start working after they are placed in a desired location. The encapsulation of nanoparticles allows their function to be preserved until they are released at a specific time or location, and this has been exploited in the development of self-healing materials and in applications such as drug delivery. Encapsulation has also been used to stabilize and control the release of substances, including flavours, fragrances and pesticides. We recently proposed a new technique for the repair of surfaces called 'repair-and-go'. In this approach, a flexible microcapsule filled with a solution of nanoparticles rolls across a surface that has been damaged, stopping to repair any defects it encounters by releasing nanoparticles into them, then moving on to the next defect. Here, we experimentally demonstrate the repair-and-go approach using droplets of oil that are stabilized with a polymer surfactant and contain CdSe nanoparticles. We show that these microcapsules can find the cracks on a surface and selectively deliver the nanoparticle contents into the crack, before moving on to find the next crack. Although the microcapsules are too large to enter the cracks, their flexible walls allow them to probe and adhere temporarily to the interior of the cracks. The release of nanoparticles is made possible by the thin microcapsule wall (comparable to the diameter of the nanoparticles) and by the favourable (hydrophobic-hydrophobic) interactions between the nanoparticle and the cracked surface. 相似文献
997.
998.
In this study, 1-(2,6-diisopropylphenyl)-2,5-di(2-thienyl)pyrrole-based metal-free organic dyes containing three different non planar electron donor groups such as methoxy or hexyloxy substituted triphenylamine and difluorenephenylamine were prepared in order to see the effect of electron donor groups on the opto-electrical properties and applied in dye-sensitized solar cells (DSSC). All three dyes showed broad absorption band in visible part of the solar spectrum (∼300 nm–600 nm). The dye (TPTDYE-3) containing sterically less hindered methoxy substituted triphenylamine was found to show relatively red shifted absorption compared to that of the dye (TPTDYE-4) containing hexyloxy substituted triphenylamine or the dye (TPTDYE-5) containing difluorenephenylamine. The optical band gaps of the three dyes were calculated to be 2.19 eV, 2.22 eV and 2.24 eV, respectively, and the highest occupied molecular orbital (HOMO) energy levels of the three dyes were found to be located at 0.65 V, 0.68 V and 0.75 V, respectively. The DSSC performance of each dye was investigated with and without coadsorbent. The maximum solar to electrical energy conversion efficiencies (η) of the DSSCs made from only sensitizer were 4.18%, 5.28% and 5.42% while those of the DSSCs made from sensitizer with coadsorbent were 5.47%, 5.58% and 5.63%, respectively. 相似文献
999.
Arshad KhanKhalid Rahman Dong Soo KimKyung Hyun Choi 《Journal of Materials Processing Technology》2012,212(3):700-706
To overcome the limitation of low production speed of electrohydrodynamic (EHD) inkjet printing technology and to fabricate low cost electronic micro-structures, this paper presents the direct deposition of copper colloidal solution through the multi-nozzle EHD inkjet printing process. Multi-nozzle EHD inkjet printing head, consisting of five nozzles, was used for simultaneous printing of electrically conductive micro-tracks onto the glass substrate. Nozzle-to-nozzle distance and experimental conditions were optimized to prevent the interaction i.e., cross-talk between electrically charged neighboring jets. After sintering in inert (N2 gas) atmosphere, printed tracks exhibited approximately five times larger resistivity (9.20 μΩ cm) than that of the bulk copper which is a remarkable achievement. These electrically conductive micro-tracks show the feasibility of multi-nozzle EHD inkjet printing technique using the copper nano-colloidal ink for low cost fabrication of microelectronic structures and devices. 相似文献
1000.
Jeong Hwan ChunKi Tae Park Dong Hyun JoJi Young Lee Sang Gon KimSun Hee Park Eun Sook LeeJy-Young Jyoung Sung Hyun Kim 《International Journal of Hydrogen Energy》2011,36(14):8422-8428
In this study, a gas diffusion layer (GDL) was modified to improve the water management ability of a proton exchange membrane fuel cell (PEMFC). We developed a novel hydrophobic/hydrophilic double micro porous layer (MPL) that was coated on a gas diffusion backing layer (GDBL). The water management properties, vapor and water permeability, of the GDL were measured and the performance of single cells was evaluated under two different humidification conditions, R.H. 100% and 50%. The modified GDL, which contained a hydrophilic MPL in the middle of the GDL and a hydrophobic MPL on the surface, performed better than the conventional GDL, which contained only a single hydrophobic MPL, regardless of humidity, where the performance of the single cell was significantly improved under the low humidification condition. The hydrophilic MPL, which was in the middle of the modified GDL, was shown to act as an internal humidifier due to its water absorption ability as assessed by measuring the vapor and water permeability of this layer. 相似文献