http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Laser-Induced Solid-Phase Doped Graphene
Choi, Insung,Jeong, Hu Young,Jung, Dae Yool,Byun, Myunghwan,Choi, Choon-Gi,Hong, Byung Hee,Choi, Sung-Yool,Lee, Keon Jae American Chemical Society 2014 ACS NANO Vol.8 No.8
<P>There have been numerous efforts to improve the performance of graphene-based electronic devices by chemical doping. Most studies have focused on gas-phase doping with chemical vapor deposition. However, that requires a complicated transfer process that causes undesired doping and defects by residual polymers. Here, we report a solid-phase synthesis of doped graphene by means of silicon carbide (SiC) substrate including a dopant source driven by pulsed laser irradiation. This method provides <I>in situ</I> direct growth of doped graphene on an insulating SiC substrate without a transfer step. A numerical simulation on the temperature history of the SiC surface during laser irradiation reveals that the surface temperature of SiC can be accurately controlled to grow nitrogen-doped graphene from the thermal decomposition of nitrogen-doped SiC. Laser-induced solid-phase doped graphene is highly promising for the realization of graphene-based nanoelectronics with desired functionalities.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2014/ancac3.2014.8.issue-8/nn5032214/production/images/medium/nn-2014-032214_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn5032214'>ACS Electronic Supporting Info</A></P>
( Sang Yool Park ),( Jung Sik Choi ),( Sang Young Seol ),( Youn Jae Lee ),( Sam Ryong Jee ),( Sung Jae Park ),( Ji Hyun Kim ),( Sang Heon Lee ),( Eun Uk Jung ) 대한내과학회 2014 대한내과학회 추계학술발표논문집 Vol.2014 No.1
Background: Pancreatic fi uid collections(PFC) may occur as a result of acute or chronic pancreatitis and can develop secondary to fi uid leakage or liquefaction of pancreatic necrosis. Methods: We collected data from 116 consecutive patients with PFC in acute severe pancreatitis and chronic pancreatitis, from January 2009 to June 2014, treated at a single center. Collection characteristics, drainage technique, and outcomes were obtained through chart review. Conservative treatments comprised of prophylactic antibiotics coverage, fi uid resuscitation, nutritional support including nasojejunal tube feeding. Results: A total of 116 patients presented with fi uid collections classifi ed as acute peripancreatic fiuid collection(n=20), acute necrotic collection(n=15), pseudocyst(n=56), and walled-off necrosis(n=25). The etiology of PFC was alcoholic in 86(74. 1%), biliary in 9(7. 8%), post-ERCP in 5(4. 3%), other in 5(4. 3%), and idiopathic in 11 patients(9. 5%). Primary catheter drainage intervention for PFC was performed in 30 patients(25. 9%); The drainage technique was percutaneous drainage in 15 patients, transmural in 12, both in 2, and transpapillary in 1. Transpapillary pancreatic duct stents bridging the leak was successfully deployed in 24 patients(20. 7%). 75 patients(64. 6%) were successfully managed without any intervention or drainage procedure. Surgical management was necessary in 6 patients(5. 1%). Reasons for surgical management in 6 patients were transverse colon fistula in 2, persistence of PFC with suspicion of pancreatic malignancy in 4 patients. The success rate of conservative treatment and Minimally Invasive treatment group was 85. 3%(64/75) and 70. 7%(29/41). Overall mortality was 2%(n=3). Conclusions: Approximately 65% of patients with PFC can be treated without an intervention and with low mortality. The study indicates that conservative approach can be preferred in terms of treating patients with PFC to the direct catheter drainage or surgical intervention due to the existence of highly responding patients to the elective procedures.
김상률(Sang Yool Kim),최미성(Mee Sung Choi) 한국의류산업학회 2000 한국의류산업학회지 Vol.2 No.2
Dyeing properties of silk fabric with loess were studied by investigating the effect of dyeing conditions, such as concentration of loess, dyeing temperature and time, on dye uptakes. And also the effects of mordant and mordanting methods on color change and dye uptakes were investigated. For the practical use, the various color fastness of dyed fabric were evaluated. The dye uptakes of dyed fabric were increased gradually with increasing concentration of loess, dyeing time and temperature. The K/S value of dyed fabric most efficient for the premordanting method. The color fastness was improved when mordants were added.
Lee, Sang Yool,Kim, Sung-Kyoung,Nguyen, Thao M.,Chung, Jin Suk,Lee, Sang Bok,Choi, Kyu Yong American Chemical Society 2011 Macromolecules Vol.44 No.6
<P>The geometry of a catalyst support has a strong influence on the catalytic activity of heterogeneous metallocene catalysts for polymerization of α-olefins and styrene. In this study, the catalytic activities of Cp*Ti(OCH<SUB>3</SUB>)<SUB>3</SUB>/MAO catalyst for styrene polymerization to syndiotactic polystyrene (sPS) have been investigated using three different types of support materials with different geometries: flat surface derived from a silicon wafer, cylindrical pores in silica nanotube reactor arrays, and random tortuous and interconnected pores in porous silica particles. With the same catalyst immobilization technique applied to these support materials, the highest titanium loading per unit support surface area has been obtained with a flat surface catalyst whereas porous silica particles of 15 nm average pore size has the lowest titanium loading per pore surface area. The metallocene catalyst supported on a flat silica surface also exhibited the highest catalyst activity per mole of titanium among different types of supported catalysts investigated in this study. The flat surface catalyst renders minimal mass transfer resistance for the catalytic components (metallocenes and MAO) as well as monomer and all the active sites are fully exposed to monomer and available for polymerization. The relatively low catalyst activity of the silica particle supported catalyst is attributed to the limited exposure of active sites to cocatalyst as well as monomer because of geometric obstructions. The catalyst deactivation kinetics for the different types of supported catalysts was very similar in the early stage of polymerization and fitted well by the first order deactivation kinetics with about 20 min of catalyst half-life. The sPS synthesized with all these supported catalysts show that sPS molecules assemble to a bundle of nanofibrils of about 30 nm in diameter.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/mamobx/2011/mamobx.2011.44.issue-6/ma1028592/production/images/medium/ma-2010-028592_0008.gif'></P>