http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Elementary Pinning Force on a Single Abrikosov Vortex in a Nb Film
Junghyun Sok 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.47 No.2
The elementary pinning force on a single Abrikosov vortex trapped in a superconducting Nb thin film was measured and found to be on the order of 10.14 N, or an average force per unit length of the vortex of 10.8 N/m, at 8.95 K. In a cross-strip superconductor/normalmetal/ insulator/superconductor(S/N/I/S) Josephson junction a single Abrikosov vortex can be nucleated and systematically moved from one pinning site to another by using the current through one superconducting electrode. The position of the vortex within the junction is determined from the distorted shape of the Fraunhofer pattern.
Junghyun Sok,주상현 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.6
Pr0:7Ca0:3MnO3 (PCMO) films with SrRuO3 (SRO) buffer layers were deposited on Pt/Ti/SiO2/Si(100) substrates at various substrate temperatures ranging from 300 ℃ to 700 ℃ by rf-magnetron sputtering. The PCMO lms were found to be crystallized at increasing substrate temperature. The electroresistance (ER) ratio of the Au/SRO/PCMO/SRO/Pt sandwich structure was enhanced by improvement of the grain size in the PCMO lms. From X-ray photoelectron microscopy (XPS) measurements after oxygen post annealing, we found that an excess of oxygen caused by the post annealing of the PCMO lms led to an increase in the Mn4+/Mn3+ ratio at the PCMO surface, resulting in an increased ER ratio. The Au/SRO/PCMO/SRO/Pt structure, which was grown at a substrate temperature of 700 ℃, showed the largest ER ratio of 5840 % after oxygen annealing at 600 ℃. As a result of surface treatment by using an oxygen plasma through the interface of the Au/SRO/PCMO/SRO/Pt sandwich structure, the reproducible property of these structures was improved.
Resistance Changes of Pr0.7Ca0.3MnO3 Films Deposited Through rf-Magnetron Sputtering
Kwangseok Lee,Junghyun Sok,Kyoungwan Park,Seungwoo Han 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.3
In this paper, the resistance-change behavior of a perovskite material was studied. In particular, Pr0.7Ca0.3MnO3 (PCMO) films were deposited on a Pt bottom electrode by using an rf-magnetron sputtering system. The PCMO films showed a resistance-switching behavior at room temperature. They were then deposited at 300 C with dierent oxygen flow rates, and the deposited films were post-annealed at various temperatures in an O2 or N2 atmosphere. The ratio of the resistance change of the post-annealed PCMO films in the high-resistance state to that in the low-resistance state in an O2 atmosphere turned out to be much larger than that of the post-annealed films in a N2 atmosphere. The electrical properties of the PCMO films were also significantly aected by the top electrode. The resistance changes of the Ag/PCMO/Pt device turned out to be larger than those of the Au/PCMO/Pt device. It can, therefore, be concluded that the O2 content and the top electrode improve the electroresistance.
( Chan-sik Kim ),( Sok Park ),( Junghyun Kim ) 한국운동영양학회 2017 Physical Activity and Nutrition (Phys Act Nutr) Vol.21 No.3
[Purpose] Advanced glycation end products (AGEs) are non-enzymatic modifications of proteins or lipids after exposure to sugars. In this review, the glycation process and AGEs are introduced, and the harmful effects of AGEs in the aging process are discussed. [Methods] Results from human and animal studies examining the mechanisms and effects of AGEs are considered. In addition, publications addressing means to attenuate glycation stress through AGE inhibitors or physical exercise are reviewed. [Results] AGEs form in hyperglycemic conditions and/or the natural process of aging. Numerous publications have demonstrated acceleration of the aging process by AGEs. Exogenous AGEs in dietary foods also trigger organ dysfunction and tissue aging. Various herbal supplements or regular physical exercise have beneficial effects on glycemic control and oxidative stress with a consequent reduction of AGE accumulation during aging. [Conclusion] The inhibition of AGE formation and accumulation in tissues can lead to an increase in lifespan.
Kim, Chan-Sik,Park, Sok,Chun, Yoonseok,Song, Wook,Kim, Hee-Jae,Kim, Junghyun MDPI 2015 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.16 No.9
<P>In the retina, a number of degenerative diseases, including glaucoma, diabetic retinopathy, and age-related macular degeneration, may occur as a result of aging. Oxidative damage is believed to contribute to the pathogenesis of aging as well as to age-related retinal disease. Although physiological exercise has been shown to reduce oxidative stress in rats and mice, it is not known whether it has a similar effect in retinal tissues. The aim of this study was to evaluate retinal oxidative stress in naturally-aged mice. In addition, we evaluated the effects of aerobic training on retinal oxidative stress by immunohistochemically evaluating oxidative stress markers. A group of twelve-week-old male mice were not exercised (young control). Two groups of twenty-two-month-old male mice were created: an old control group and a treadmill exercise group. The old control group mice were not exercised. The treadmill exercise group mice ran on a treadmill (5 to 12 m/min, 30 to 60 min/day, 3 days/week for 12 weeks). The retinal thickness and number of cells in the ganglion cell layer of the naturally-aged mice were reduced compared to those in the young control mice. However, treadmill exercise reversed these morphological changes in the retinas. We evaluated retinal expression of carboxymethyllysine (CML), 8-hydroxy-2′-deoxyguanosine (8-OHdG) and nitrotyrosine. The retinas from the aged mice showed increased CML, 8-OHdG, and nitrotyrosine immunostaining intensities compared to young control mice. The exercise group exhibited significantly lower CML levels and nitro-oxidative stress than the old control group. These results suggest that regular exercise can reduce retinal oxidative stress and that physiological exercise may be distinctly advantageous in reducing retinal oxidative stress.</P>
Jongchan Lee,Kyusang Choi,Junghyun Sok 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.4
The piezoelectric resonance signal of an AT-cut quartz crystal detected through the inductive pulse method was analyzed. Although the detection mechanism of the inductive method has been determined, its basic characteristics have not been fully ascertained. The detected signal strengths were linearly proportional to the pulse height, the sine function of the pulse width, and the absolute value of the sinc function of the frequency of the rf pulse. All the experimental results could be fully understood with the use of the Fourier transform of the rf pulse, which assured that the piezoelectric signal of the inductive pulse method was an effect of the interference between the input rf pulse and the induced electric polarization of the piezoelectric materials.