http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kanade, K.G.,Baeg, J.O.,Kong, K.j.,Kale, B.B.,Lee, S.M.,Moon, S.J.,Lee, C.W.,Yoon, S. Pergamon Press ; Elsevier Science Ltd 2008 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.33 No.23
We report here the novel approach to synthesis of layer perovskite photocatalysts, Pb<SUB>2</SUB>Ga<SUB>2</SUB>Nb<SUB>2</SUB>O<SUB>10</SUB> and RbPb<SUB>2</SUB>Nb<SUB>2</SUB>O<SUB>7</SUB> using solid state route (SSR) and molten salt synthesis (MSS) method. The reported modified MSS method has advantage over conventional SSR method for uniform particle size, well-defined crystal structure, controlled morphology and stoichiometry vis-a-vis photocatalysis. The structural study was performed using X-ray difractometry (XRD) and computation based on density functional theory (DFT). The simulation study showed that both the compounds belong to the Ruddlesden-Popper phase (A'<SUB>2</SUB>A<SUB>n-1</SUB>B<SUB>n</SUB>O<SUB>3n+1</SUB>; n=2 or 3). The surface morphology of the materials was studied using field emission scanning electron microscope (FESEM) and high resolution transmission electron microscope (HRTEM). The average particles size of perovskites Pb<SUB>2</SUB>Ga<SUB>2</SUB>Nb<SUB>2</SUB>O<SUB>10</SUB> and RbPb<SUB>2</SUB>Nb<SUB>2</SUB>O<SUB>7</SUB> was in the range 20-40 and 70-90nm respectively. The efficacy of these materials was studied to particle size and morphology as a visible light driven photocatalyst for the hydrogen generation from H<SUB>2</SUB>S. Electronic band structure with DOS has also been performed for both the materials. Being a stable single-phase ternary-layered oxide perovskites and band gap (2.75eV) in visible domain, they may have potential applications in electronic devices as well.
Lee, Y.S.,Lim, K.S.,Oh, J.E.,Yoon, A.R.,Joo, W.S.,Kim, H.S.,Yun, C.O.,Kim, S.W. Elsevier Science Publishers 2015 Journal of controlled release Vol.205 No.-
Multipotent mesenchymal stem cells (MSCs) promise a therapeutic alternative for many debilitating and incurable diseases. However, one of the major limitations for the therapeutic application of human MSC (hMSC) is the lengthy ex vivo expansion time for preparing a sufficient amount of cells due to the low engraftment rate after transplantation. To solve this conundrum, a porous biodegradable polymeric microsphere was investigated as a potential scaffold for the delivery of MSCs. The modified water/oil/water (W<SUB>1</SUB>/O/W<SUB>2</SUB>) double emulsion solvent evaporation method was used for the construction of porous microspheres. PEI<SUB>1.8k</SUB> was blended with poly(lactic-co-glycolic acid) (PLGA) to enhance electrostatic cellular attachment to the microspheres. The porous PLGA/PEI<SUB>1.8k</SUB> (PPP) particles demonstrated an average particle size of 290μm and an average pore size of 14.3μm, providing a micro-carrier for the MSC delivery. PPP particles allowed for better attachment of rMSCs than non-porous PLGA/PEI<SUB>1.8k</SUB> (NPP) particles and non-porous (NP) and porous PLGA (PP) microspheres. rMSC successfully grew on the PPP particles for 2weeks in vitro. Next, PPP particles loaded with 3 different amounts of hMSC showed increased in vivo engraftment rates and maintained the stemness characteristics of hMSC compared with hMSCs-alone group in rats 2weeks after intramyocardial administration. These customized PPP particles for MSC delivery are a biodegradable and injectable scaffold that can be used for clinical applications.
Yoon, K.,Hwang, G.,Chung, J.,Kim, H.g.,Kwon, O.,Kihm, K.D.,Lee, J.S. Pergamon Press ; Elsevier Science Ltd 2014 Carbon Vol.76 No.-
Despite the importance of the accurate measurement of the thermal conductivity of graphene, deviations in previous data are still quite large due to the low signal-to-noise ratio in the measurement of graphene temperature, the uncertainties in the measurement of the heat dissipation, and the influence of the polymeric residues. Herein, we improve signal-to-noise ratio by using null point scanning thermal microscopy, which profiles temperature quantitatively with nanoscale spatial resolution (~50nm), independently of both the heat flux through the air and the variation of the sample surface properties. Also, we control and monitor the heat generation rate accurately by heating the suspended graphene bridge electrically. Furthermore, we prevent the disturbance of the thermal conductivity caused by the polymeric residues by using polydimethylsiloxane stamping method, which leaves much less residue than using polymethylmethacrylate. The thermal conductivity values of graphene, whose length and width are 3.6 and 5.52μm, respectively, were measured as 2430+/-190, 2150+/-170, and 2100+/-160W/mK at the peak temperatures of 335, 361, and 366K, respectively, with much smaller error range compared to the previously reported values. The measured values exceed the highest value (~2000W/mK at room temperature) obtained for graphite.
Yoon, O.J.,Kang, S.M.,Moon, S.M.,Jung, J.K.,Choi, I.S.,Yoon, K.R. North-Holland 2007 Journal of non-crystalline solids Vol.353 No.11-12
We report helicon plasma-enhanced, chemical vapor deposition (helicon-PECVD) of iron (Fe) nanoparticles onto multiwalled carbon nanotubes (MWCNTs) with ferrocene as an iron source. Ferrocene was evaporated from the bubbler by heating, and the helicon plasma treatment was performed with the evaporated ferrocene and hydrogen gas at (-)DC bias voltage. The resulting MWCNT/Fe nanoparticle hybrids were characterized by X-ray fluorescence spectroscopy, X-ray diffraction spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, micro-Raman spectroscopy, and superconducting quantum interference device magnetometry.
Intracellular Pools of Inositol Phosphates in NIH3T3 Cells Damaged with UV Light
Yoon, Y S,Shin, I C,Joe, C O,Kang, K W 한국유전학회 1990 Genes & Genomics Vol.12 No.4
The relationship between inositol phosphates metabolism and inhibition of DNA synthesis was examined. The DNA synthesis rate measured by the ³H-labeled thymidine incorporation into cellular DNA in NIH3T3 fibroblast treated with UV indicates that there exists a resting stage of DNA synthesis in cells exposed to UV light. Intracellular levels of inositol phosphates in cells were decreased within 5 minutes after UV treatment. The size of inositol-1,4,5-triphosphate pool in NIH3T3 cells was most sensitive to UV treatment. Competitive binding assay was carried out for the measurement of intracellular IP₃ contents based on the competition for the binding sites with lable and unIalled IP₃. Microsomal preparations from bovine adrenal cortex were used as binding protein. This study indicated that UV irradiation might indirectly affect DNA synthesis by impediment of inositol phosphate metabolism in the cells.
COSMIC-RAY PROTON AND HELIUM SPECTRA FROM THE FIRST CREAM FLIGHT
Yoon, Y. S.,Ahn, H. S.,Allison, P. S.,Bagliesi, M. G.,Beatty, J. J.,Bigongiari, G.,Boyle, P. J.,Childers, J. T.,Conklin, N. B.,Coutu, S.,DuVernois, M. A.,Ganel, O.,Han, J. H.,Jeon, J. A.,Kim, K. C.,Le IOP Publishing 2011 The Astrophysical journal Vol.728 No.2
<P>Cosmic-ray proton and helium spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass experiment flown for 42 days in Antarctica in the 2004-2005 austral summer season. High-energy cosmic-ray data were collected at an average altitude of similar to 38.5 km with an average atmospheric overburden of similar to 3.9 g cm(-2). Individual elements are clearly separated with a charge resolution of similar to 0.15 e (in charge units) and similar to 0.2 e for protons and helium nuclei, respectively. The measured spectra at the top of the atmosphere are represented by power laws with a spectral index of -2.66 +/- 0.02 for protons from 2.5 TeV to 250 TeV and -2.58 +/- 0.02 for helium nuclei from 630 GeV nucleon(-1) to 63 TeV nucleon-1. They are harder than previous measurements at a few tens of GeV nucleon-1. The helium flux is higher than that expected from the extrapolation of the power law fitted to the lower-energy data. The relative abundance of protons to helium nuclei is 9.1 +/- 0.5 for the range from 2.5 TeV nucleon(-1) to 63 TeV nucleon(-1). This ratio is considerably smaller than the previous measurements at a few tens of GeV nucleon(-1).</P>
A new rf plasma oxidation method for the insulating AlOx barrier in magnetic tunneling junctions
K.S.Yoon,양정엽,J.H.Park,W.J.Choi,Y.D.Kim,C.O.Kim,J.P.Hong 한국물리학회 2002 Current Applied Physics Vol.2 No.5
An rf remote plasma oxidation technique to form an insulating barrier was carried out to enhance properties of CoFe/AlOx/CoFe magnetic tunneling junctions. The rf remote plasma method was found to reduce self-bias effect on the barrier during the rf oxidation process and to increase atomic oxygen concentration in a plasma state. Experimentally observed rms roughness of the barrier in our magnetic tunnel junction was decreased from 5 to 1.5 AA. In addition, electrical breakdown voltage and magnetoresistance of our magnetic tunnel junction devices were increased from 0.8 V up to 1.2 V and from 7% up to 30%, respectively. 2002 Elsevier Science B.V. All rights reserved.