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A New Inertial Self-adaptive Gradient Algorithm for the Split Feasibility Problem and an Application to the Sparse Recovery Problem

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Acta Mathematica Sinica,English Series 2023年第12期39卷 2489-2506页

作者： Nguyen The VINH Pham Thi HOAI Le Anh DUNG yeol je cho Department of Mathematical Analysis University of Transport and Communications3 Cau Giay StreetHanoiVietnam Department of Applied Mathematics School of Applied Mathematics and InformaticsHano University of Science and Technology1 Dai Co Viet RoadHanoiVietnam Department of Mathematics and Informatics Hanoi University of Education136 Xuan ThuyCau GiayHanoiVietnam Department of Mathematics Education Gyeongsang National UniversityJinju52828Republicof Korea

In this paper,by combining the inertial technique and the gradient descent method with Polyak's stepsizes,we propose a novel inertial self-adaptive gradient algorithm to solve the split feasi-bility problem in Hilbert spaces and prove some strong and weak convergence theorems of our method under standard *** examine the performance of our method on the sparse recovery prob-lem beside an example in an infinite dimensional Hilbert space with synthetic data and give some numerical results to show the potential applicability of the proposed method and comparisons with related methods emphasize it further.

关键词： Split feasibility problem CQ algorithm Hilbert space sparse recovery problem

Fixed Point and Common Fixed Point Theorems for Cyclic Quasi-Contractions in Metric and Ultrametric Spaces

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Advances in Pure Mathematics 2012年第6期2卷 401-407页

作者： Parin Chaipunya yeol je cho Wutiphol Sintunavarat Poom Kumam Department of Mathematics Education and the RINS Gyeongsang National University Chinju Korea Department of Mathematics Faculty of Science King Mongkut’s University of Technology Thonburi Bangkok Thailand

In this paper, we prove introduce some fixed point theorems for quasi-contraction under the cyclical conditions. Then, we point out that a common fixed point extension is also applicable via our earlier results equipped together with a weaker cyclical properties, namely a co-cyclic representation. Examples are as well provided along this paper.

关键词： Cyclic Quasi-Contraction Co-Cyclic Quasi-Contraction Metric Space Ultrametric Space

Photophysical,optical,and photocatalytic hydrogen production properties of layered-type BaNb_(2-x)Ta_(x)P_(2)O_(11)(x=0,0.5,1.0,1.5,and 2.0)compounds

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Journal of Materials Science & Technology 2022年第3期98卷 26-32页

作者： Min je Kang Gill Sang Han In Sun cho Department of Materials Science and Engineering Ajou UniversitySuwon 16499Republic of Korea Department of Energy Systems Research Ajou UniversitySuwon 16499Republic of Korea School of Advanced Materials Science and Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea

Layered-type metal phosphates of BaNb_(2-x)Ta_(x)P_(2)O_(11)(x=0,0.5,1.0,1.5,and 2.0)were synthesized using a solid-state reaction *** photophysical,optical,and photocatalytic hydrogen production properties of the resulting powders were investigated for the first ***-pure and homogeneous powders with irregular morphologies were obtained at a calcination temperature of 1200℃.As the Ta content increased,the interlayer distance along the c-axis increased by up to 0.14%.Additionally,the optical bandgap values increased from 3.32 to 3.59 *** energy band positions were estimated from the Mott–Schottky ***_(2)P_(2)O_(11)(x=0)exhibited the lowest conduction band edge position(-0.14 V *** normal hydrogen electrode,NHE),which is located above the water reduction potential(0.0 V ***).In comparison,BaTa_(2)P_(2)O_(11)(x=2.0)exhibited the highest conduction band edge position(-0.29 V ***),comparable to that of TiO_(2).The photocatalytic activity for hydrogen produced from splitting water was measured under ultraviolet light ***,BaTa_(2)P_(2)O_(11)exhibited the highest activity(7.3μmol/h),which was 15 and 10 times larger than BaNb_(2)P_(2)O_(11)(0.5μmol/h)and nano-TiO_(2)(0.7μmol/h),*** activity of BaTa_(2)P_(2)O_(11)increased to 24.4μmol/h after deposition of the NiO_(x)co-catalyst(1 wt.%),which remained stable during continuous operation(~35 h).

关键词： BaNb_(2)P_(2)O_(11) BaTa_(2)P_(2)O_(11) Layered crystal structure Bandgap Band edge positions Photocatalytic hydrogen production

Calcium and Calmodulin-Mediated Regulation of Gene Expression in Plants

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Molecular Plant 2009年第1期2卷 13-21页

作者： Min Chul Kim Woo Sik Chung Dae-Jin Yun Moo je cho Division of Applied Life Science (BK21 Program) Plant Molecular Biology and Biotechnology Research Center and Environmental Biotechnology National Core Research Center Gyeongsang National University Jinju 660-701 Korea

Sessile plants have developed a very delicate system to sense diverse kinds of endogenous developmental cues and exogenous environmental stimuli by using a simple Ca^2＋ ion. Calmodulin （CAM） is the predominant Ca^2＋ sensor and plays a crucial role in decoding the Ca^2＋ signatures into proper cellular responses in various cellular compartments in eukaryotes. A growing body of evidence points to the importance of Ca^2＋ and CaM in the regulation of the transcriptional process during plant responses to endogenous and exogenous stimuli. Here, we review recent progress in the identification of transcriptional regulators modulated by Ca^2＋ and CaM and in the assessment of their functional significance during plant signal transduction in response to biotic and abiotic stresses and developmental cues.

关键词： Abiotic/environmental stress calcium signaling/transport gene expression.

Point-defect engineering of nanoporous CuBi_(2)O_(4) photocathode via rapid thermal processing for enhanced photoelectrochemical activity

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Journal of Energy Chemistry 2022年第8期31卷 201-209,I0007页

作者： Li Qu Runfa Tan Arumugam Sivanantham Min je Kang Yoo Jae jeong Dong Hyun Seo Sungkyu Kim In Sun cho Department of Materials Science&Engineering Ajou UniversitySuwon 16499South Korea Department of Energy Systems Research Ajou UniversitySuwon 16499South Korea Department of Nanotechnology and Advanced Materials Engineering Sejong UniversitySeoul 05006South Korea

Engineering point defects such as metal and oxygen vacancies play a crucial role in manipulating the electrical,optical,and catalytic properties of oxide semiconductors for solar water ***,we synthesized nanoporous CuBi_(2)O_(4)(np-CBO)photocathodes and engineered their surface point defects via rapid thermal processing(RTP)in controlled atmospheres(O_(2),N_(2),and vacuum).We found that the O_(2)-RTP treatment of np-CBO increased the charge carrier density effectively without hampering the nanoporous morphology,which was attributed to the formation of copper vacancies(VCu).Further analyses revealed that the amounts of oxygen vacancies(Vo)and Cu^(1+)were reduced simultaneously,and the relative electrochemical active surface area increased after the O_(2)-RTP ***,the point defects(VC_(u),Cu^(1+),and Vo)regulated np-CBO achieved a superb water-splitting photocurrent density of-1.81 m A cm^(-2) under simulated sunlight illumination,which is attributed to the enhanced charge transport and transfer properties resulting from the regulated surface point ***,the reversibility of the formation of the point defects was checked by sequential RTP treatments(O_(2)-N_(2)-O_(2)-N_(2)),demonstrating the strong dependence of photocurrent response on the RTP ***,the surface point defect engineering via RTP treatment in a controlled atmosphere is a rapid and facile strategy to promote charge transport and transfer properties of photoelectrodes for efficient solar water-splitting.

关键词： Nanoporous Copper bismuth oxide Rapid thermal processing Copper vacancy Charge transport

Room-temperature sputtered electrocatalyst WSe2 nanomaterials for hydrogen evolution reaction

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Journal of Energy Chemistry 2020年第8期29卷 107-111,I0004页

作者： Jae Hyeon Nam Myeong je Jang Hye Yeon Jang Woojin Park Xiaolei Wang Sung Mook choi Byungjin cho Department of Advanced Material Engineering Chungbuk National UniversityChungdae-ro 1Seowon-GuCheongjuChungbuk 28644Republic of Korea Surface Technology Department Korea Institute of Materials Science797 ChangwonDaeroSungsan-guChangwon 51508Republic of Korea Advanced Materials Engineering Korea University of Science and Technology(UST)217 Gajeong-roYuseong-guDaejeon 34113Republic of Korea Department of Chemical and Materials Engineering University of Alberta9211116 Street NWEdmontonAlberta T6C 1H9Canada

The low-temperature physical vapor deposition process of atomically thin two-dimensional transition metal dichalcogenide(2D TMD) has been gaining attention owing to the cost-effective production of diverse electrochemical catalysts for hydrogen evolution reaction(HER) applications. We, herein, propose a simple route toward the cost-effective physical vapor deposition process of 2D WSe2 layered nanofilms as HER electrochemical catalysts using RF magnetron sputtering at room temperature(<27℃). By controlling the variable sputtering parameters, such as RF power and deposition time, the loading amount and electrochemical surface area(ECSA) of WSe2 films deposited on carbon paper can be carefully determined. The surface of the sputtered WSe2 films are partially oxidized, which may cause spherical-shaped particles. Regardless of the loading amount of WSe2, Tafel slopes of WSe2 electrodes in the HER test are narrowly distributed to be ~120–138 mV dec-1, which indicates the excellent reproducibility of intrinsic catalytic activity. By considering the trade-off between the loading amount and ECSA, the best HER performance is clearly observed in the 200 W-15 min sample with an overpotential of 220 mV at a current density of 10 mA cm-2. Such a simple sputtering method at low temperature can be easily expanded to other 2D TMD electrochemical catalysts, promising potentially practical electrocatalysts.

关键词： Two dimensional nanomaterials Sputtering WSe2 nanofilm Electrocatalyst Hydrogen evolution reaction

Effects of honing treatment on AIP-TiN and TiAlN coated end-mill for high speed machining

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 83-87页

作者： Jae-Young HEO Sung-Hak cho Tae-Jin je Kwang-Ho KIM Hyung-Woo LEE Myung-Chang KANG National Core Research Center for Hybrid Materials Solution Pusan National University Nano Machining Laboratory Korea Institute of Machinery and Material (KIMM) 171 Jang-dong Yuseong-Gu Daejeon 305-343 Korea

The objective of this work is to compare the tool performance of TiN and TiA1N coated carbides end-mills deposited by an arc ion plating （ALP） method, using honing treatment to polish the cutting edge surface sleekly. The curve of surface roughness versus honing time showed a rapid improvement initially and thereafter became steady, manifesting a saturation effect. The optimal honing time related to surface roughness was determined to be approximately 20 s. As the surface roughness increased, the critical loads reduced. At an average surface roughness （Ra） of 0.028 p.m, the highest critical loads of TiN and TiAlN coating layers were 98 and 114 N, respectively. Tool performances of uncoated and coated tools were conducted under high speed machining （HSM） of AISI D2 cold-worked die steel （62 HRC）. Consequently, the TiAlN coated end-mill using honing treatment showed excellent tool life under HSM conditions.

关键词： TiA1N arc ion plating honing treatment high speed machining tool life

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

Aqueous-processable,naphthalene diimide-based polymers for eco-friendly fabrication of high-performance,n-type organic electrolyte-gated transistors

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Science China Chemistry 2022年第5期65卷 973-978页

作者： Dahyun jeong Min je Kim Seungjin Lee Jin-Woo Lee Youngwoong Kim Hyeong Jun Kim jeong Ho cho Bumjoon J.Kim Department of Chemical and Biomolecular Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea Department of Chemical and Biomolecular Engineering Yonsei UniversitySeoul 03722Republic of Korea Department of Chemical and Biomolecular Engineering Sogang UniversitySeoul 04107Republic of Korea

Organic electrolyte-gated transistors(OEGTs) have the benefits of low power consumption and large current ***,the electrical performance of n-type OEGTs lags far behind that of p-type *** this study,we design a series of polymers,P(NDITEG-T) and P(NDIMTEG-T),comprising a naphthalene diimide backbone for n-type charge transport and oligo(ethylene glycol)(OEG) side chains for high ionic conductivity and eco-friendly solution *** incorporation of the OEG chain facilitates the electrochemical doping of the semiconductor by ions to realize high-performance,n-type ***,in OEGTs,P(NDITEG-T) achieves a high electron mobility of 1.0 × 10^(-1) cm^(2) V^(-1) s^(-1),which represents the highest value reported for solution-processed,n-type *** is noted that the fabrication of the OEGTs is achieved by solution processing with eco-friendly ethanol/water mixtures in virtue of the hydrophilic OEG *** work demonstrates the molecular design of the P(NDITEG-T) polymer and its significant ability to produce aqueous-processable,high-performance,and n-type OEGTs.

关键词： organic electrolyte-gated transistors n-type transistors oligo(ethylene glycol)polymers eco-friendly solution process high electron mobility