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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

On the stacking fault forming probability and stacking fault energy in carbon-doped 17 at%Mn steels via transmission electron microscopy and atom probe tomography

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Journal of Materials Science & Technology 2022年第20期115卷 177-188页

作者： Hyo Ju Bae Kwang kyu Ko Muhammad Ishtiaq Jung Gi kim Hyokyung sung Jae Bok Seol Department of Materials Engineering and Convergence Technology Center for K-metalGyeongsang National University(GNU)Jinju 52828South Korea

Assessing the stacking fault forming probability(P_(sf)) and stacking fault energy(SFE)in medium-or highMn base structural materials can anticipate and elucidate the microstructural evolution before and after ***,these two parameters have been determined from theoretical calculations and empirical ***,the estimation of SFE values in Fe–Mn–C ternary systems is a longstanding debate due to the complicated nature of carbon:that is,whether the carbon doping indeed plays an important role in the formation of stacking faults;and how the amount of carbon atoms exist at grain boundaries or at internal grains with respect to the nominal carbon doping ***,the use of atom probe tomography and transmission electron microscopy(TEM)unveils the influence of carbondoping contents on the structural properties of dual-phase Fe–17 Mn–x C(x=0–1.56 at%)steels,such as carbon segregation free energy at grain boundaries,carbon concentration in grain interior,interplanar D-spacings,and mean width of intrinsic stacking faults,which are essential for SFE *** next determined the Psfvalues by two different methods,viz.,reciprocal-space electron diffraction measurements and stacking fault width measurements in real-space TEM ***,SFEs in the Fe–17 Mn–x C systems were calculated on the basis of the generally-known SFE *** found that the high amount of carbon doping gives rise to the increased SFE from 8.6 to 13.5 m J/m^(2)with non-linear *** SFE trend varies inversely with the mean width of localized stacking faults,which pass through both other stacking faults and pre-existingε-martensite plates without much difficulty at their intersecting *** high amount of carbon doping acts twofold,through increasing the segregation free energy(due to more carbon at grain boundaries)and large lattice expansion(due to increased soluble carbon at internal grains).The experimental data obtained here strengthens the composition-

关键词： Stacking fault formation probability Stacking fault energy High-Mn steel Electron diffraction

Diagnostic criteria for autoimmune chronic pancreatitis revisited

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World Journal of Gastroenterology 2006年第16期12卷 2487-2496页

作者： kyu-Pyo kim Myung-Hwan kim Jong Cheol kim Sang Soo Lee Dong Wan Seo sung Koo Lee Department of Internal Medicine University of Ulsan College of MedicineAsan Medical CenterSeoulKorea

Autoimmune chronic pancreatitis （AIP） is increasingly being recognized worldwidely, as knowledge of this entity builds up. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response to the oral steroid therapy in contrast to ordinary chronic pancreatitis. Although many characteristic findings of AIP have been described, definite diagnostic criteria have not been fully established. In the year 2002, the Japan Pancreas Society published the diagnostic criteria of AIP and many clinicians around the world use these criteria for the diagnosis of AIP. The diagnostic criteria proposed by the Japan Pancreas Society, however, are not completely satisfactory and some groups use their own criteria in reporting AIP. This review discusses several potential limitations of current diagnostic criteria for this increasingly recognized condition. The manuscript is organized to emphasize the need for convening a consensus to develop improved diagnostic criteria.

关键词： Autoimmune chronic pancreatitis Diagnostic criteria

Internal modification in transparent hybrid germanium-silica plates using plasma formation induced by a femtosecond laser

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中国有色金属学会会刊：英文版 2012年第S3期22卷 808-812页

作者： Ji-Wook YOON Jung-kyu PARK Kwang-Ho kim Myung-Chang KANG sung-Hak CHO Nano Machining Laboratory Korea Institute of Machinery and Materials Department of Nano-Mechatronics University of Science and Technology National Core Research Center for Hybrid Materials Solution Pusan National University

The fabrication of an internal diffraction grating with photoinduced refractive index modification in planar hybrid germanium-silica plates was demonstrated using low-density plasma formation excited by a high-intensity femtosecond (150 fs) Ti:sapphire laser (λp=790 nm).The refractive index modifications with diameters ranging from 400 nm to 3 μm were photoinduced after plasma formation occurred upon irradiation with peak intensities of more than 2×1013 W/*** graded refractive index profile was fabricated to be a symmetric around from the center of the point at which low-density plasma occurred.

关键词： diffraction grating refractive index modification plasma formation hybrid germanium-silica plate femtosecond laser

Improved Hybrid Beamforming for mmWave Multi-User Massive MIMO

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Computers, Materials & Continua 2021年第6期67卷 3057-3070页

作者： Ji-sung Jung Won-Seok Lee Yeong-Rong Lee Jaeho kim Hyoung-kyu Song Department of Information and Communication Engineering and Convergence Engineering for Intelligent Drone Sejong UniversitySeoul05006Korea Department of Electrical Engineering Sejong UniversitySeoul05006Korea

Massive multiple input multiple output(MIMO)has become essential for the increase of capacity as the millimeter-wave(mmWave)communication is ***,hybrid beamforming systems have been studied since full-digital beamforming is impractical due to high cost and power consumption of the radio frequency(RF)*** paper proposes a hybrid beamforming scheme to improve the spectral efciency for multi-user MIMO(MU-MIMO)*** a frequency selective fading environment,hybrid beamforming schemes suffer from performance degradation since the analog precoder performs the same precoding for all *** mitigate performance degradation,this paper uses the average channel covariance matrix for all subcarriers and considers an iterative algorithm to design analog precoder using approximation *** analog precoder is iteratively updated for each column until it *** proposed scheme can reduce errors in the approximating process of the overall spectral *** scheme can be applied to fully-connected and partially-connected *** simulation results show that spectral efciency performance for the proposed scheme is better than the conventional *** proposed scheme can achieve similar performance with full-digital beamforming by using a sufciently large number of RF ***,this paper shows that the proposed scheme outperforms other schemes in the frequency selective fading *** performance improvement can be achieved in both structures.

关键词： Hybrid precoding massive MIMO MU-MIMO mmwave frequency selective fading

Underwater endoscopic mucosal resection for neoplasms in the pyloric ring of the stomach: Four case reports

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World Journal of Clinical Cases 2020年第14期8卷 3050-3056页

作者： Dong Hyun kim Seon-Young Park Chang Hwan Park Hyun Soo kim sung kyu Choi Division of Gastroenterology Department of Internal MedicineChonnam National University Hospital and Medical SchoolGwangju 61469South Korea

BACKGROUND Tumors located in the pylorus are technically more complex to resect by endoscopic resection,as the anatomical characteristics of this region can affect the adequate assessment of margins and performance of the *** reported the results of underwater endoscopic mucosal resection(UEMR)of benign mucosal neoplasms located in the pyloric *** SUMMARY This case series describes 4 patients with 4 mucosal neoplasms located in the pyloric *** diameter of each neoplasm was less than 15 *** performed UEMR for the *** immersion enabled slight floating of the lesions,resulting in easy *** achieved en bloc resection with a snare and electrosurgical *** procedure were performed within 3 min without adverse *** examination showed low-grade dysplasia with clear resection margins in one case and hyperplastic polyps in three *** UEMR can be an effective and safe treatment method for neoplasms in the gastric pyloric ring.

关键词： Duodenoscopy Endoscopic mucosal resection Neoplasm Pylorus Stomach Case report

Spin Self-Assembled Clay Nanocomposite Passivation Layers Made from a Photocrosslinkable Poly（vinyl alcohol） and Na^-Montmorillonite Enhance the Environmental Stability of Organic Thin-Film Transistors

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Chinese Journal of Chemistry 2016年第11期34卷 1103-1108页

作者： Hayoung Jeon Seonuk Park Sooji Nam Kwonwoo Shin sung-Ryong kim Se Hyun kim Jaeyoung Jang Tae kyu An POSTECH Organic Electronics Laboratory Polymer Research Institute Department of Chemical Engineering Pohang University of Science and Technology Pohang 790-784 Republic of Korea Smart I/O Control Device Research Section Electronics and Telecommunications Research Institute Daejeon 305- 700 Republic of Korea Nano Materials & Components Research Center Korea Electronics Technology Institute (KET1) Seongsam-si Gyeonggi-do 13509 Republic of Korea Department of Polymer Science & Engineering Korea National University of Transportation 50 Daekak-Ro Chungju 27469 Republic of Korea School of Chemical Engineering Yeungnam University 280 Daehak-Ro Gyeongsan Gyeongbuk 38541 Republic of Korea Department of Energy Engineering Hanyang University Seoul 133-791 Republic of Korea

We investigated the effects of the multilayer polymer-clay nanohybrid passivation films on the stability of pentacene organic thin-film transistors （OTFTs） exposed to air and UV irradiation. Well-ordered multilayer films were deposited by the spin-assisted layer-by-layer assembly method using photocrosslinkable poly（vinyl alcohol） with the N-methyl-4（4＇-formylstyryl）pyridinium methosulfate acetal group （SbQ-PVA） and Na＋-montmorillonite in a water-based solution process. When photocrosslinked, these SbQ-PVA/clay multilayers were found to serve as excellent barriers to 02 and UV-light. Moreover, when used as passivation layers, they enhanced the stability of pen- tacene OTFT devices exposed to air and UV radiation.

关键词： polymer-clay passivation layer-by-layer montmorillonite long-term stability

Early extrahepatic recurrence as a pivotal factor for survival after hepatocellular carcinoma resection:A 15-year observational study

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World Journal of Gastroenterology 2022年第36期28卷 5351-5363页

作者： Jae Hyun Yoon sung kyu Choi sung Bum Cho Hee Joon kim Yang Seok Ko Chung Hwan Jun Department of Gastroenterology and Hepatology Chonnam National University Hospital and College of MedicineGwangju 61469South Korea Department of Gastroenterology and Hepatology Hwasun Chonnam National University Hospital and College of MedicineHwasun 58128South Korea Department of Surgery Chonnam National University Hospital and College of MedicineGwangju 61469South Korea Department of Surgery Hwasun Chonnam National University Hospital and College of MedicineHwasun 58128South Korea Department of Internal Medicine Mokpo Hankook HospitalMokpo 58643South Korea

BACKGROUND Surgical resection is one of the most widely used modalities for the treatment of hepatocellular carcinoma(HCC).Early extrahepatic recurrence(EHR)of HCC after surgical resection is considered to be closely associated with poor ***,data regarding risk factors and survival outcomes of early EHR after surgical resection remain *** To investigate the clinical features and risk factors of early EHR and elucidate its association with survival *** From January 2004 to December 2019,we enrolled treatment-naïve patients who were≥18 years and underwent surgical resection for HCC in two tertiary academic *** excluding patients with tumor types other than HCC and/or ineligible data,this retrospective study finally included 779 *** resection of HCC was performed according to the physicians’decisions and the EHR was diagnosed based on contrast-enhanced computed tomography or magnetic resonance imaging,and pathologic confirmation was performed in selected *** Cox regression analysis was performed to identify the variables associated with *** Early EHR within 2 years after surgery was diagnosed in 9.5%of patients during a median followup period of 4.4 *** recurrence-free survival period was 5.2 mo,and the median time to EHR was 8.8 mo in patients with early *** 52.7%of patients with early EHR,EHR occurred as the first recurrence of HCC after surgical *** multivariate analysis,serum albumin100 U/L,surgical margin involvement,venous and/or lymphatic involvement,satellite nodules,tumor necrosis detected by pathology,tumor size≥7 cm,and macrovascular invasion were determined as risk factors associated with early *** sub-categorizing the patients according to the number of risk factors,the rates of both EHR and survival showed a significant correlation with the risk of early ***,multivariate analysis revealed that early E

关键词： Early extrahepatic recurrence Hepatocellular carcinoma Prognosis Surgery Survival

First discovery of a cave-dwelling Tineid moth(Lepidoptera, Tineidae) from East Asia

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Journal of Forestry Research 2014年第3期25卷 647-651页

作者： Bong-kyu Byun Sat-Byul Shin Yang-Seop Bae Do sung kim Yong Geun Choi Department of Biological Science and Biotechnology Hannam University Division of Life Sciences University of Incheon The Institute for Conservation of Wild Species

In this study, we report Monopis crocicapitella （Clemens, 1859）（Tineidae）, which was collected from bat guano in a cave in the southern region of Korea, for the first time from East Asia. We briefly redescribe and illustrate the external morphology and genital structures of both sexes. Also, we discuss the local habitat characteristics and some of the ecological information that was observed during our field investi-gation.

关键词： Monopis Tineidae Lepidoptera Bat guano new record,Korea East Asia.