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Theoretical Simulation of Surface Evolution Using the Random Deposition and Surface Relaxation for Metal Oxide Film in Atomic Layer Deposition

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Journal of Materials Science & Technology 2010年第4期26卷 371-374页

作者： Ji-hoon Ahn Se-Hun Kwon Jin-Hyock kim Ja-Yong kim Sang-Won Kang Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology373-1Kusong-dongYusong-guTaejon 305-701Korea Hynix Semiconductor Incorporated San 136-1Ami-riBubal-eubIcheon-siKyongki-do467-701Korea

Atomic layer deposition （ALD） has become an essential deposition method for forming nanometer scale thin films in the microelectronics industry, and its applications have been extended to multi-component thin films, as well as to single metal oxide films. In order to investigate the development of the surface structure of ultra-thin film qualitatively as well as quantitatively, ALD processes are simulated with a molecular scale. For this simulation, the film materials are deposited on a imaginary substrate that consists of small lattice. The deposition behaviors are described by using random deposition （RD） model or random deposition with surface relaxation （RDSR） model as the ALD growth mode, and the proposed model was applied to the deposition of SrO-TiO2 thin films. Through this work, growth characteristics such as surface morphology, deposited film coverage can be predicted.

关键词： Atomic layer deposition Random deposition SrO-TiO2

Injection molding of micro patterned PMMA plate

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 148-152页

作者： Yeong-Eun YOO Tae-hoon kim Tae-Jin JE Doo-Sun CHOI Chang-Wan kim Sun-Kyung kim Department of Nanomanufacturing Technology KIMM 171 Jang-dong Yusung-gu Daejeon 305-343 Korea Department of Product Design and Manufacturing Seoul National University of Technology

A plastic plate with surface micro features was injection molded to investigate the effect of pressure rise of melt on the replication of the micro structures. Prism pattern, which is used in many optical applications, was selected as a model pattern. The prism pattern is 50 μm in pitch and 108° in the vertical angle. The overall size of the plate was 335 minx213 mm and the thickness of the plate varied linearly from 2.6 mm to 0.7 ram. The prism pattern was firstly machined on the nickel plated core block using micro diamond tool and this machined pattern core was installed in a mold for injection molding of prism patterned plate. Polymethyl methacrylate （PMMA） was used as a molding material. The pressure and temperature of the melt in the cavity were measured at different positions in the cavity and the replication of the pattern was also measured at the same positions. The results show that the pressure or temperature profile through the process depends on the shape and the size of the plate. The replication is affected by the temperature and pressure profiles at the early stage of filling, which is right after the melt reaches the position to be measured.

关键词： micro prism pattern injection molding replication pressure profile temperature profile

Verification and Correction of Cloud Base and Top Height Retrievals from Ka–band Cloud Radar in Boseong,Korea

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Advances in Atmospheric Sciences 2016年第1期33卷 73-84页

作者： Su-Bin OH Yeon-Hee kim Ki-hoon kim Chun-Ho CHO Eunha LIM Numerical Data Application Division National Institute of Meteorological Sciences KMA Republic of Korea Applied Meteorology Research Division National Institute of Meteorological Sciences KMA Republic of Korea Observation Research Division National Institute of Meteorological Sciences KMA Republic of Korea National Institute of Meteorological Sciences KMA Republic of Korea

In this study,cloud base height（CBH） and cloud top height（CTH） observed by the Ka-band（33.44 GHz） cloud radar at the Boseong National Center for Intensive Observation of Severe Weather during fall 2013（September-November） were verified and *** comparative verification,CBH and CTH were obtained using a ceilometer（CL51） and the Communication,Ocean and Meteorological Satellite（COMS）.During rainfall,the CBH and CTH observed by the cloud radar were lower than observed by the ceilometer and COMS because of signal attenuation due to raindrops,and this difference increased with rainfall *** dry periods,however,the CBH and CTH observed by the cloud radar,ceilometer,and COMS were *** and low-density clouds were observed more effectively by the cloud radar compared with the ceilometer and *** cases of rainfall or missing cloud radar data,the ceilometer and COMS data were proven effective in correcting or compensating the cloud radar *** corrected cloud data were used to classify cloud types,which revealed that low clouds occurred most frequently.

关键词： cloud radar ceilometer satellite retrieval cloud base height cloud top height cloud type

Endoscopic and clinicopathologic characteristics of early gastric cancer with high microsatellite instability

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World Journal of Gastroenterology 2012年第27期18卷 3571-3577页

作者： Jaehoon Jahng Young hoon Youn Kwang Hyun kim Junghwan Yu Yong Chan Lee Woo Jin Hyung Sung hoon Noh Hyunki kim Hoguen kim Hyojin Park Sang In Lee Department of Internal Medicine Gangnam Severance HospitalYonsei University College of MedicineSeoul 135-720South Korea Department of Internal Medicine Institute of GastroenterologyYonsei University College of MedicineSeoul 100-753South Korea Department of Surgery Yonsei University College of MedicineSeoul 100-753South Korea Department of Pathology Yonsei University College of MedicineSeoul 100-753South Korea

AIM： To investigate endoscopic and clinicopathologic characteristics of early gastric cancer （EGC） according to microsatellite instability phenotype. METHODS： Data were retrospectively collected from a single tertiary referral center. Of 981 EGC patients surgically treated between December 2003 and October 2007, 73 consecutive EGC patients with two or more microsatellite instability （MSI） mutation [high MSI （MSI-H）] and 146 consecutive EGC patients with one or no MSI mutation （non-MSI-H） were selected. The endoscopic and clinicopathologic features were compared between the MSI-H and non-MSI-H EGC ***： In terms of endoscopic characteristics, MSI-H EGCs more frequently presented with elevated pattern （OR 4.38, 95% Cl： 2.40-8.01, P 〈 0.001）, moderate- to-severe atrophy in the surrounding mucosa （OR 1.91, 95% CI： 1.05-3.47, P = 0.033）, antral location （OR 3.99, 95% CI： 2.12-7.52, P 〈 0.001） and synchronous le- sions, compared to non-MSI-H EGCs （OR 2.65, 95% CI： 1.16-6.07, P = 0.021）. Other significant clinicopatholog- ic characteristics of MSI-H EGC included predominance of female sex （OR 2.77, 95% CI： 1.53-4.99, P 〈 0.001）, older age （〉 70 years）（OR 3.30, 95% CI： 1.57-6.92, P = 0.002）, better histologic differentiation （OR 2.35, 95% Cl： 1.27-4.34, P = 0.007）, intestinal type by Lau- ren classification （OR 2.34, 95% CI： 1.15-4.76, P = 0.019）, absence of a signet ring cell component （OR 2.44, 95% CI： 1.02-5.86, P = 0.046）, presence of mu- cinous component （OR 5.06, 95% Cl： 1.27-20.17, P = 0.022）, moderate-to-severe lymphoid stromal reaction （OR 3.95, 95% CI： 1.59-9.80, P = 0.003）, and co-exist- ing underlying adenoma （OR 2.66, 95% CI： 1.43-4.95, P = 0.002）. CONCLUSION： MSI-H EGC is associated with unique endoscopic and clinicopathologic characteristics includ- ing frequent presentation in protruded type, co-exist- ing underlying adenoma, and synchronous lesions.

关键词： Microsatellite instability Early gastric can-cer Endoscopic characteristic Advanced gastric cancer

Stretchable and colorless freestanding microwire arrays for transparent solar cells with flexibility

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Light(Science & Applications) 2019年第1期8卷 47-59页

作者： Sung Bum Kang Ji-Hwan kim Myeong hoon Jeong Amit Sanger Chan Ul kim Chil-Min kim Kyoung Jin Choi Department of Materials Science and Engineering Ulsan National Institute of Science and Technology(UNIST)Ulsan 44919Republic of Korea Department of Emerging Materials Science Daegu Gyeongbuk Institute of Science and Technology(DGIST)Daegu 42988Republic of Korea

Transparent solar cells(TSCs)are emerging devices that combine the advantages of visible transparency and light-toelectricity ***,existing TSCs are based predominantly on organics,dyes,and perovskites;however,the rigidity and color-tinted transparent nature of those devices strongly limit the utility of the resulting TSCs for realworld ***,we demonstrate a flexible,color-neutral,and high-efficiency TSC based on a freestanding form of n-silicon microwires(SiMWs).Flat-tip SiMWs with controllable spacing are fabricated via deep-reactive ion etching and embedded in a freestanding transparent polymer *** light transmittance can be tuned from ~10 to 55% by adjusting the spacing between the *** TSCs,a heterojunction is formed with a p-type polymer in the top portion of the n-type flat-tip *** contact with an indium-doped ZnO film occurs at the bottom,and the side surface has an Al2O3 passivation ***,slanted-tip SiMWs are developed by a novel solventassisted wet etching method to manipulate light ***-difference time-domain simulation revealed that the reflected light from slanted-tip SiMWs helps light-matter interactions in adjacent *** TSC based on the slanted-tip SiMWs demonstrates 8%efficiency at a visible transparency of 10% with *** efficiency is the highest among Si-based TSCs and comparable with that of state-of-the-art neutral-color TSCs based on organic–inorganic hybrid perovskite and ***,unlike others,the stretchable and transparent platform in this study is promising for future TSCs.

关键词： transparent transparency spacing

Follow-up strategy for early detection of delayed pseudoaneurysms in patients with blunt traumatic spleen injury: A single-center retrospective study

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World Journal of Gastrointestinal Surgery 2024年第10期16卷 3163-3170页

作者： Sung hoon Cho Gun Woo kim Suyeong Hwang Kyoung hoon Lim Department of Surgery Trauma CenterKyungpook National University HospitalSchool of MedicineKyungpook National UniversityDaegu 41944South Korea

BACKGROUND The spleen is the most commonly injured solid organ in blunt abdominal trauma,and splenic pseudoaneurysm rupture is associated with a high risk of *** management has become the standard treatment for hemodynam-ically stable patients with splenic *** the other hand,delayed splenic pseudoaneurysms can develop in any patient,and at present,there are no known risk factors that may reliably predict their ***,there is a lack of consensus regarding the most appropriate strategies for monitoring and mana-ging splenic injuries,especially lower-grade(I-III).AIM To determine the predictors of pseudo-aneurysm formation following splenic injury and develop follow-up strategies for early detection of *** We retrospectively analyzed patients who visited the Level I Trauma Center bet-ween January 2013 and December 2022 and were diagnosed with spleen injuries after blunt abdominal *** Using the American Association for the Surgery of Trauma spleen injury scale,the splenic injuries were categorized into the following order based on severity:Grade I(n=57,17.6%),grade II(n=114,35.3%),grade III(n=89,27.6%),grade IV(n=50,15.5%),and grade V(n=13,4.0%).Of a total of 323 patients,35 underwent splenectomy and 126 underwent angioembolization.19 underwent delayed angioembolization,and 5 under-went both initial and delayed *** 14 patients who had undergone delayed angioembolization,no extravasation or pseudoaneurysm was observed on the initial computed tomography *** are no particular patient-related risk factors for the formation of a delayed splenic pseudoaneurysm,which can occur even in a grade I spleen injury or even 21 days after the *** mean detection time for a delayed pseudoaneurysm was 6.26±5.4(1-21,median:6,inter-quartile range:2-9)*** We recommend regular follow-up computed tomography scans,including an arterial and portal venous phase,at least 1 week an

关键词： Blunt trauma Spleen injury Delayed pseudoaneurysm Angioembolization Nonoperative management

Nanocrystalline Iron Pyrophosphate-Regulated Amorphous Phosphate Overlayer for Enhancing Solar Water Oxidation

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Nano-Micro Letters 2022年第12期14卷 387-400页

作者： Chengkai Xia Yuankai Li Minyeong Je Jaekyum kim Sung Min Cho Chang Hyuck Choi Heechae Choi Tae-hoon kim Jung Kyu kim School of Chemical Engineering Sungkyunkwan University(SKKU)2066 Seobu-roJangan-guSuwon 16419Republic of Korea Theoretical Materials and Chemistry Group Institute of Inorganic ChemistryUniversity of CologneGreinstr.650939 CologneGermany Department of Chemistry Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Department of Materials Science and Engineering Engineering Research CenterChonnam National UniversityGwangju 61186Republic of Korea

A rational regulation of the solar water splitting reaction pathway by adjusting the surface composition and phase structure of catalysts is a substantial approach to ameliorate the sluggish reaction kinetics and improve the energy conversion *** this study,we demonstrate a nanocrystalline iron pyrophosphate(Fe_(4)(P_(2)O_(7))_(3),FePy)-regulated hybrid overlayer with amorphous iron phosphate(FePO_(4),FePi)on the surface of metal oxide nanostructure with boosted photoelectrochemical(PEC)water *** manipulating the facile electrochemical surface treatment followed by the phosphating process,nanocrystalline FePy is localized in the FePi amorphous overlayer to form a heterogeneous hybrid *** FePy-regulated hybrid overlayer(FePy@FePi)results in significantly enhanced PEC performance with long-term *** with the homogeneous FePi amorphous overlayer,FePy@FePi can improve the charge transfer efficiency more significantly,from 60% of FePi to 79%of FePy@*** density-functional theory calculations reveal that the coexistence of FePi and FePy phases on the surface of metal oxide results in much better oxygen evolution reaction kinetics,where the FePi was found to have a typical down-hill reaction for the conversion from OH*to O_(2),while FePy has a low free energy for the formation of OH*.

关键词： Water oxidation Photoelectrochemical cell Metal pyrophosphate Electrochemical surface treatment

Complications and management of forgotten long-term biliary stents

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World Journal of Gastroenterology 2017年第4期23卷 622-628页

作者： Se hoon Sohn Jae Hyun Park Kook Hyun kim Tae Nyeun kim Division of Gastroenterology and Hepatology Department of Internal MedicineYeungnam University College of MedicineDaegu 42415South Korea

AIMTo evaluate complications and management outcomes of retained long-term plastic biliary *** plastic biliary stent placement was performed in 802 patients at Yeungnam University Hospital between January 2000 and December 2014. Follow-up loss with a subsequently forgotten stent for more than 12 mo occurred in 38 patients. We retrospectively examined the cause of biliary stent insertion, status of stents, complications associated with biliary stents and management outcomes of long-term plastic biliary stents. Continuous variables were analyzed using the t test. Observed frequencies in subsets of the study population were compared using Fisher’s exact test and χ2 tests. Statistical significance was defined as P < 0.05 (two-tailed).RESULTSMean age of patients was 73.7 ± 12 years and male-to-female ratio was 2.2:1. Indications of plastic biliary stent insertion were bile duct stones (63.2%, 24/38) and benign bile duct stricture (52.6%, 20/38). Mean duration of retained plastic stent was 22.6 ± 12.2 mo, and in 10 cases (26.3%), stents were retained for more than 24 mo. Common bile duct (CBD) stones or sludge were found in most cases (92.1%, 35/38). The most common complication was acute cholangitis (94.7%, 36/38). Stent removal by endoscopic approach was successfully performed in 92.1% (35/38) of the cases. In 3 cases, an additional plastic stent was inserted alongside the previous stent due to failure of the stent removal. Endoscopic removal of bile duct stones was successful in 73.7% (28/38) of the cases. When patients were divided into two groups by duration of stent placement (12 to 24 mo vs over 24 mo), there were no differences in the development of cholangitis, presence of biliary stones, and success rate of endoscopic removal of stones and biliary *** most common complication of retained long-term plastic biliary stents was acute cholangitis associated with CBD stones. Endos

关键词： Biliary stent Long-term complications Forgotten stents Acute cholangitis Biliary stone

Tailoring strength-ductility balance of caliber-rolled AZ31 Mg alloy through subsequent annealing

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Journal of Magnesium and Alloys 2020年第1期8卷 163-171页

作者： Taein Kong Byung Je Kwak Jonghyun kim Jeong Hun Lee Sung Hyuk Park Ji hoon kim Young hoon Moon Hyun Sik Yoon Taekyung Lee School of Mechanical Engineering Pusan National UniversityBusan 46241Republic of Korea Advanced Forming Process R&D Group Korea Institute of Industrial TechnologyUlsan 44413Republic of Korea College of Materials Science and Engineering Chongqing UniversityChongqing 400044China School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Department of Naval Architecture and Ocean Engineering Pusan National UniversityBusan 46241Republic of Korea

Recently,multi-pass caliber rolling has been shown to be effective for Mg *** study investigated the effect of subsequent annealing on the mechanical properties of a caliber-rolled AZ31 Mg alloy to modulate the strength-ductility *** annealing gave rise to different trends in mechanical properties depending on the temperature ***-temperature annealing(T≤473 K)exhibited a typical trade-off relationship,where an increase in annealing temperature resulted in increased ductility but decreased strength and *** a heat treatment did not degrade the high strength-ductility balance of the caliber-rolled alloy,suggesting that the mechanical properties could be tailored for different potential *** contrast,high-temperature annealing(T>473 K)caused a simultaneous deterioration in strength,hardness,and ductility with increasing annealing *** differences are discussed in terms of the varying microstructural features under the different investigated annealing regimes.

关键词： AZ31 Mg alloy Caliber rolling Annealing Grain growth Mechanical improvement Twinning