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characterization of three-dimensional channel reservoirs using ensemble kalman filter assisted by principal component analysis

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Petroleum Science 2020年第1期17卷 182-195页

作者： Byeongcheol kang Hyungsik jung Hoonyoung Jeong Jonggeun choe Department of Energy Systems Engineering Seoul National UniversitySeoul 08826South Korea

Ensemble-based analyses are useful to compare equiprobable scenarios of the reservoir ***,they require a large suite of reservoir models to cover high uncertainty in heterogeneous and complex reservoir *** stable convergence in ensemble kalman filter(EnkF),increasing ensemble size can be one of the solutions,but it causes high computational cost in large-scale reservoir *** this paper,we propose a preprocessing of good initial model selection to reduce the ensemble size,and then,EnkF is utilized to predict production performances *** the model selection scheme,representative models are chosen by using principal component analysis(PcA)and clustering *** dimension of initial models is reduced using PcA,and the reduced models are grouped by ***,we choose and simulate representative models from the cluster groups to compare errors of production predictions with historical observation *** representative model with the minimum error is considered as the best model,and we use the ensemble members near the best model in the cluster plane for applying *** demonstrate the proposed scheme for two 3D models that EnkF provides reliable assimilation results with much reduced computation time.

关键词： channel reservoir characterization Model selection scheme Egg model Principal component analysis(PcA) Ensemble kalman filter(EnkF) History matching

Supramolecular Polymer Intertwined Free-Standing Bifunctional Membrane catalysts for All-Temperature Flexible Zn-Air Batteries

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Nano-Micro Letters 2022年第11期14卷 341-360页

作者： Nayantara k.Wagh Sambhaji S.Shinde chi Ho Lee Sung-Hae kim Dong-Hyung kim Han-Don Um Sang Uck Lee jung-Ho Lee Department of Materials Science and chemical Engineering Hanyang UniversityAnsanRepublic of Korea Department of Applied chemistry Center for Bionano Intelligence Education and ResearchHanyang UniversityAnsanRepublic of Korea Department of chemical Engineering Kangwon National UniversityChuncheonGangwon 24341Republic of Korea

Rational construction of flexible free-standing electrocatalysts featuring long-lasting durability,high efficiency,and wide temperature tolerance under harsh practical operations are fundamentally significant for commercial zinc-air ***,3D flexible free-standing bifunctional membrane electrocatalysts composed of covalently cross-linked supramolecular polymer networks with nitrogen-deficient carbon nitride nanotubes are fabricated(referred to as PEMAc@NDcN)by a facile self-templated ***@NDcN demonstrates the lowest reversible oxygen bifunctional activity of 0.61 V with exceptional long-lasting durability,which outperforms those of commercial Pt/c and RuO_(2).Theoretical calculations and control experi-ments reveal the boosted electron transfer,electrolyte mass/ion transports,and abundant active surface site ***,the constructed alkaline Zn-air battery with PEMAc@NDcN air-cathode reveals superb power density,capacity,and discharge-charge cycling stability(over 2160 cycles)compared to the reference Pt/c+RuO_(2).Solid-state Zn-air batteries enable a high power density of 211 mW cm^(−2),energy density of 1056 Wh kg^(−1),stable charge-discharge cycling of 2580 cycles for 50 mA cm^(−2),and wide temperature tolerance from−40 to 70℃with retention of 86%capacity compared to room-temperature counterparts,illustrating prospects over harsh operations.

关键词： Flexible free-standing membrane electrocatalysts Supramolecular polymer Alkaline and flexible solid-state Zn-air batteries All-temperature operations High capacity and energy density

Effects of irradiation on superconducting properties of small-grained MgB_(2) thin films

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chinese Physics B 2023年第12期32卷 534-540页

作者：刘丽 jung Min Lee Yoonseok Han Jaegu Song chorong kim Jaekwon Suk Won Nam kang 刘杰 Soon-Gil jung Tuson Park center for Quantum Materials and Superconductivity(cQMS) Sungkyunkwan UniversitySuwon 16419Republic of Korea Department of Physics Sungkyunkwan UniversitySuwon 16419Republic of Korea Institute of Modern Physics Chinese Academy of Sciences(CAS)Lanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of Sciences(UCAS)Beijing 100049China korea Multi-purpose Accelerator complex Korea Atomic Energy Research InstituteGyeongjuGyeongbuk 38180Republic of Korea Department of Physics Education Sunchon National UniversitySuncheon 57922Republic of Korea

We investigate the effect of ion irradiation on MgB_(2) thin films with small grains of approximately 122 nm and 140 *** flux pinning by grain boundaries is insignificant in the pristine MgB_(2) films due to good inter-grain connectivity,but is significantly improved after 120-keV Mn-ion *** scaling behavior of the flux pinning force density for the ion-irradiated MgB_(2) thin films with nanoscale grains demonstrates the predominance of pinning by grain boundaries,in contrast to the single-crystalline MgB_(2) films where normal point pinning was dominant after low-energy ion *** results suggest that irradiation-induced defects can accumulate near the grain boundaries in metallic MgB_(2) superconductors.

关键词： MgB_(2)films grain boundaries flux pinning low-energy ion irradiation

Oxidative coupling of methane over LaAlO3 perovskite catalysts prepared by a co-precipitation method: Effect of co-precipitation pH value

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Journal of Energy chemistry 2019年第8期28卷 1-8,I0001页

作者： Yujin Sim Jihoon Yoo Jeong-Myeong Ha Ji chul jung Department of chemical Engineering Myongji UniversityYongin 17058 Republic of Korea clean Energy Research center Korea Institute of Science and TechnologySeoul 02792 Republic of Korea

Oxidative coupling of methane(OcM) was conducted over LaAlO3X catalysts that were prepared by a coprecipitation method using different co-precipitation pH values(X = 6–10). The aim is to investigate the effect of p H values on the catalytic activity of La AlO3 catalysts in this reaction. The results showed that the co-precipitation pH value affected greatly on the formation of chemical species of precipitate precursors in the co-precipitation step, leading to different phases of the finally obtained LaAlO3 *** the co-precipitation pH value increased up to 8, the lanthanum-related phases such as La2 O3 and La(OH)3 were gradually formed as by-products, preventing the formation of LaAlO3 perovskite crystalline structure and facilitating the formation of oxygen vacancies on catalyst surface. However, at pH value of9 or higher, the lanthanum content in the precipitate precursor was increased greatly. Not LaAlO3 perovskite but lanthanum-related phases were developed as main phases, reducing their catalytic activities in this reaction. Among LaAlO3 catalysts, the one prepared at pH = 8 showed the highest c2 yield due to its well-developed oxygen vacancies and electrophilic lattice oxygen. Therefore, the co-precipitation pH value strongly affected the LaAlO3 catalyst activity in OcM reaction. A precious pH control should be required to prepare various perovskite catalysts for the OcM.

关键词： LaAlO3 Perovskite Oxidative coupling of methane co-precipitation pH value

Environmental friendly synthesis of hierarchical mesoporous platinum nanoparticles templated by fucoidan biopolymer for enhanced hydrogen evolution reaction

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Journal of Materials Science & Technology 2020年第11期42卷 185-190页

作者： Seung Man Lim kyunglee kang Hongje Jang jung Tae Park Department of chemical Engineering Konkuk University120 Neungdong-roGwangjin-guSeoul 05029Republic of Korea Department of chemistry Kwangwoon University20 Cwangwoon-roNowon-guSeoul 01897Republic of Korea

Researching novel hydrogen evolution reaction(HER)catalysts with enhanced electrocatalytic activity,excellent stability,and cost-efficiency is of great significance for the large-scale hydrogen production from industrial electrolysis *** report the preparation of hierarchical mesoporous-Pt nanoparticles(HM-Pt NPs)with coral-like rough surface morphologies using environmental friendly and biocompatible fucoidan(Fu)biopolymer as a surface engineering compound and its application to electrocatalysts for *** designed HM-Pt NPs yields better mass activity of electrocatalysts compared to a commercial Pt/***-Pt NPs showed an overpotential of 33 mV at 10 mA cm-2 for the HER in 0.5 MH2SO4,which was highly comparable to that of the commercial Pt/c catalysts(29 mV).However,the amount of HM-Pt NPs loaded in glassy carbon electrode(0.033 mg mL-1)was approximately 20 times lower than that of the commercial Pt/c(0.64 mg *** HM-Pt NPs also maintained high catalytic stability with a consistent HER current density after 1000 continuous *** excellent HER performance is attributed to the improved electrochemical surface area,highly porous structure,and good surface wettability of the HM-Pt NPs,which results in enhanced electrocatalytic activity,decreased resistance at the electrode/electrolyte interface,and facile penetration of the electrolytes inside the electrode.

关键词： Mesoporous Fucoidan Biopolymer Low Pt content Hydrogen evolution reaction

Impact of exergaming on young children's school day energy expenditure and moderate-to-vigorous physical activity levels

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Journal of Sport and Health Science 2017年第1期6卷 11-16页

作者： Zan Gao Zachary Pope jung Eun Lee David Stodden Nida Roncesvalles Denis Pasco charles c.Huang Du Feng School of kinesiology The University of MinnesotaMinneapolisMN 55455USA Department of Applied Human Science The University of MinnesotaDuluthMN 55812USA Department of Physical Education and Athletic Training University of South CarolinaColumbiaSC 29201USA Department of kinesiology and Sport Management Texas Tech UniversityLubbockTX 79409USA School of Education The University of Bourgogne Franche-ComtéBesançon 25000France School or Exercise and Sports Science Wayland Baptist UniversityPlainviewTX 79072USA School of Nursing University of NevadaLas VegasNV 89154USA

Background: Although emerging research is demonstrating the potential health impact of exergaming,investigations have primarily been conducted in laboratory settings among small samples with short-term *** on the effectiveness of exergaming in underserved children's objective physical activity(PA) in population-based settings is also ***,most empirical studies have only included 1 type of exergame in the ***,this study's purpose was to investigate the long-term impact of a multigame exergaming intervention among underserved children integrated within school ***,this study examined the effect of exergaming on children's accelerometer-determined sedentary behavior(SB),light PA,moderate-to-vigorous PA(MVPA),and energy expenditure(EE) over 2 years as compared with regular physical education(PE) ***: A total of 261 second-and third-grade children(134 girls,127 boys; mean age 8.27 years) were recruited from 2 Texas elementary ***'s pre-test 3-day SB,light PA,MVPA,and EE at school were assessed in the fall of *** were assigned to 1 of 2groups:(1) exergaming/PE group(125 min weekly of exergaming-based PA program) and (2) comparison group(125 min weekly of PE).PA(SB,light PA,and MVPA) and EE outcome variables were assessed again in 2013(post-test) and 2014(follow-up).Results: Significant time effects were observed for SB(F(1,162)=25.0,p0.05,η~2= 0.004).Subsequent pairwise comparisons revealed significant increases from pre-to post-test for light PA(pchanges in SB(p>0.05).conversely,significant decreases occurred in light PA(pces seen in MVPA(p=0.08) and EE(p=0.06) over the same time period.A significant increase was seen,however,for SB from post-te

关键词： Active video games childhood obesity Light physical activity Moderate-to-vigorous physical activity Physical education Sedentary behavior

SUV39H1-driven NFATc1 methylation is essential for the c-cbl-mediated degradation of NFATc1 in an osteoclast lineage

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Genes & Diseases 2024年第4期11卷 86-89页

作者： Do-Won Jeong Hye-Jin kim Jong-Wan Park Seulbee Lee Hyeryeon jung Eugene c.Yi Nacksung kime Yang-Sook chun Department of Biomedical Sciences Seoul National University College of MedicineSeoul 03080Republic of Korea Department of Physiology Seoul National University College of MedicineSeoul 03080Republic of Korea Ischemic/Hypoxic Disease Institute Seoul National University College of MedicineSeoul 03080Republic of Korea Department of Molecular Medicine and Biopharmaceutical Sciences Graduate School of Convergence Science and Technology and College of Medicine Or College of PharmacySeoul National UniversitySeoul 03080Republic of Korea Department of Pharmacology Chonnam National University Medical SchoolGwangju 61469Republic of Korea

Bone undergoes continuous remodeling by tightly-coordinated actions of bone-resorbing osteoclasts and boneforming osteoblasts.1 Recent studies document that the dysregulation of histone methylation profiles is associated with the progression of ***,the specific epigenetic modifiers are incompletely *** this study,we demonstrate an inhibitory role of a variegation 3-9 homolog 1(SUV39H1)in osteoclast formation.

关键词： osteoclast remodeling incomplete

Monitoring continuous k-nearest neighbor queries in the hybrid wireless network

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Journal of Zhejiang University-Science c(computers and Electronics) 2011年第3期12卷 213-220页

作者： Young-Mo kWON HaRim jung Yon Dohn cHUNG Department of computer Science and Engineering Korea UniversitySeoul 136-713Korea

In a mobile/pervasive computing environment,one of the most important goals of monitoring continuous spatial queries is to reduce communication cost for *** work uses many cellular wireless connections,which would easily become the performance bottleneck of the overall *** paper introduces a novel continuous kNN query monitoring method to reduce communication cost in the hybrid wireless network,where the moving objects in the wireless broadcasting system construct the ad-hoc *** results prove the efficiency of the proposed method,which leverages the wireless broadcasting channel as well as the WiFi link to alleviate the burden on the cellular uplink communication cost.

关键词： continuous kNN query monitoring Ad-hoc networks Wireless broadcasting systems

A Note on the Stability of Jordan Triple Higher Ring Derivations

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Acta Mathematica Sinica,English Series 2009年第12期25卷 1975-1986页

作者： Jaiok ROH Yong-Soo jung Ick-Soon cHANG Department of Mathematics Hallym University Department of Mathematics Sunmoon University Department of Mathematics Mokwon University

In the present paper, we establish the stability and the superstability of a functional inequality corresponding to the functional equation fn（xyx） = ∑i＋j＋k=n fi（x）fj （y）fk（x）. In addition, we take account ... 详细信息

关键词： functional inequality Jordan triple higher ring derivation stability radical range