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Femtosecond Tm-Ho co-doped fiber laser using a bulk-structured Bi2Se3 topological insulator

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Chinese Physics B 2018年第9期27卷 137-143页

作者： Jinho lee Ju Han lee School of Electrical and Computer Engineering University of SeoulSeoul 02504Republic of Kore

We experimentally demonstrate a femtosecond mode-locked thulium-holmium（Tm-Ho） co-doped fiber laser incorporating a saturable absorber（SA） based on a bulk-structured bismuth selenide（Bi2Se3） topological insulator（TI）. The SA was prepared by depositing a mechanically exfoliated Bi2Se3 TI layer onto a side-polished optical fiber platform. Unlike high-quality nano-structured Bi2Se3 TI-based SA, bulk-structured Bi2Se3 with non-negligible oxidation was used as a saturable absorption material for this experimental demonstration due to its easy fabrication process. The saturation power and modulation depth of the prepared SA were measured to be -28.6 W and -13.4%, respectively. By incorporating the prepared SA into a Tm-Ho co-doped fiber ring cavity, stable soliton pulses with a temporal width of - 853 fs could be generated at 1912.12 nm. The 3-dB bandwidth of the mode-locked pulse was measured to be -4.87 nm. This experimental demonstration reaffirms that Bi2Se3 is a superb base material for mid-infrared passive mode-locking even under oxidation.

关键词： topological insulator mode-locked lasers femtosecond pulse fiber lasers

Complete remission of gastric Burkitt's lymphoma after eradication of Helicobacter pylori

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World Journal of Gastroenterology 2009年第45期15卷 5746-5750页

作者： Isabelle Baumgaertner Christiane Copie-Bergman Michael Levy corinne Haioun Antoine Charachon Maryse Baia Iradj Sobhani Jean-Charles Delchier Department of Gastroenterology AP-HP Henri Mondor Hospital Paris 12 University 51 avenue du maréchal de Lattre de Tassigny Créteil 94000 France Department of Pathology AP-HP Henri Mondor Hospital Paris 12 University 51 avenue du maréchal de Lattre de Tassigny Créteil 94000 France Department of Hematology AP-HP Henri Mondor Hospital Paris 12 University 51 avenue du maréchal de Lattre de Tassigny Créteil 94000 France

Burkitt＇s lymphoma is a highly aggressive non-Hodgkin lymphoma, often presenting in extra-nodal sites. It generally has a poor spontaneous outcome and needs aggressive treatment with systemic and intrathecal chemotherapy. Occurrence at the gastric site is rare. We report the case of a 39-year old woman who presented with a prominent ulcerated lesion of the antrum corresponding histologically to a Burkitt＇s lymphoma associated with He/icobacter py/ori （H pylori） infection. Interphase fluorescence in situ hybridization （FISH） demonstrated c-MYC gene rearrangement in tumour cells without BCL2 or BCL6 gene translocations. Ulcer healing and tumour regression with a complete histological response were obtained 8 wk after Hpylori eradication. In spite of this complete remission, taking into account the high risk of recurrence, the patient received systemic and intrathecal chemotherapy. Two years later, the patient remained in complete remission. This is the first report of a gastric Burkitt＇s lymphoma responding to Hpylori eradication. These findings raise the question of the potential role of H pylori in the pathogenesis of some gastric Burkitt＇s lymphomas, and show the importance of searching for and eradicating the bacteria in combination with conventional chemotherapy regimens.

关键词： Burkitt's lymphoma Gastric lymphoma Helicobacter pylori Therapy

Velocity Profiles between Two Baffles in a Shell and Tube Heat Exchanger

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Journal of Thermal Science 2015年第4期24卷 356-363页

作者： Tae-Hyun Chang Chang-Hoan lee Hae-Soo lee Kwon-Soo lee Senior Research Fellow of RESEAT Korea Institute of Science and Technology Information Korea Institute of Science and Technology Information Postdoctoral Research Fellow School of Mechanical Engineering of Kyungnam University International University of Korea

Heat exchangers are extensively utilized for waste heat recovery,oil refining,chemical processing,and steam *** this study,velocity profiles are measured using a 3D particle image velocimetry(PIV)system between two baffles in a shell and tube heat exchanger for parallel and counter *** PIV and computational fluid dynamics results show the occurrence of some strong vectors near the *** vectors are assumed due to the clearance between the inner tubes and the front ***,the major parts of the vectors are moved out through the bottom opening of the rear baffle,and other vectors produce a large circle between the two *** simulations are conducted to investigate the effects of the baffle on the heat exchanger using the Fluent *** k-εturbulence model is employed to calculate the flows along the heat exchanger.

关键词： Baffle P1V Shell and tube heat exchanger Cut off ratio CFD

Effects of elastic-plastic properties of materials on residual indentation impressions in nano-indentation using sharp indenter

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中国有色金属学会会刊：英文版 2012年第S3期22卷 585-595页

作者： Jung-Min lee Chan-Joo lee Kyung-Hun lee Byung-Min KIM Dongnam Regional Division Korea Institute of Industrial Technology Precision Manufacturing Systems Division Pusan National University School of Mechanical Engineering Pusan National University

One of the primary features of nano-indentation technique is that the contact area induced by an indenter is indirectly measured by a relationship between the penetration depth and the known geometry of the ***,this indirect measurement occasionally leads to inaccurate properties of the indented *** objective of this study is to investigate the effects of E/σr and the strain hardening exponents n of materials on the behaviors of pile-up and sink-in in nano-indentation and to predict n values of materials from the residual indentation *** relations between the residual indentation profile and n value of the indented material were identified by dimensional ***,they were numerically formulated using FE analysis of nano-indentation for 140 different combinations of elastic-plastic parameters such as E,σy and *** parameters of hrp/hm,herp/hm,Rr/hm and HO&P/Hreal were introduced as various dimensionless parameters to represent and quantify the residual indentation profile after *** were subsequently characterized as dimensionless functions using n and E/σr ***,the validity of these functions was verified through 3D FE analysis of nano-indentation for Al 6061-T6 and AISI 1010 materials.

关键词： nano-indentation pile-up sink-in strain hardening exponent FE simulation

The effect of the dopant's reactivity for high-performance 2D MoS2 thin-film transistor

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Nano Research 2021年第1期14卷 198-204页

作者： Ha.leem lee Sora Bak Joosung Kim Hyoyoung lee Center for Integrated Nanostructure Physics(CINAP) Institute for Basic Science(IBS)Suwon 16419Republic of Korea Department ofChem istryy Sungkyunkwan University Suwon 16419Republic of Korea Department of Energy Science Sungkyunkwan UniversitySuwon 16419Republic of Korea Department of Biophysics Sungkyunkwan UniversitySuwon 16419Republic of Korea

There are many studies on the solution-processed thin-film transistor(TFT)using transition metal dichalcogenide(TMD)***,it is hard to control the electrical property of chemically exfoliated TMD materials compared to the chemical vapor deposition *** investigation into the electrical modulation behavior of exfoliated two-dimensional(2D)material is important tofabricate weH-modulated electronic devices via solution ***,we report the effects of reactivity of organic dopants on MoS2 and investigate how the chemical doping behavior influences the electrical properties of *** band state of dopants,which is related to the electron-withdrawing and donating behavior of chemical dopant,provides a proportional shift in the threshold voltages(Vth)of their field-effect transistors(FETs).However,on/off current ratio(Ion/Ioff)and mobility(μ)are strongly influenced by the defect density depending on the reactivity of doping reaction,rather than the band state of organic *** the in-depth study on the doping reaction,we fabricate a FET and a TFT,having high mobility and a relatively high on/off ratio(10^(4))using a solution process.

关键词： 2D materials functionalization thin-film transistor doping defect

Catalysts for electrochemical ammonia oxidation:Trend,challenge,and promise

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Science China Materials 2022年第12期65卷 3334-3352页

作者： Sol a.lee Mi Gyoung lee Ho Won Jang Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Republic of Korea Department of Electrical and Computer Engineering University of TorontoToronto M5S 3G4OntarioCanada Advanced Institute of Convergence Technology Seoul National UniversitySuwon 16229Republic of Korea

Developing sustainable and clean energy technology is critial to address the current energy and environmental *** an energy carrier,hydrogen has been getting attention due to its abundance,high energy density,and zero carbon *** to the difficulty of hydrogen storage and transport,the electro-oxidation of ammonia shows great potential for renewable energy since it satisfies both energy supply and environmental protection as a carbon-free fuel with high hydrogen ***,ammonia electro-oxidation is a sluggish reaction and shows low *** the complicated mechanism and intermediates is conducive to developing efficient electrocatalysts with high catalytic activity and *** review begins with the ammonia oxidation technologies and their *** two typical mechanisms for ammonia electro-oxidation,Oswin-Salomon mechanism and Gerischer-Mauerer mechanism,are discussed,and attention to the poisoning species is ***,the electrocatalysts for ammonia reaction are classified into Pt-based catalysts and non-noble metal-based catalysts,and their performances are reviewed with various *** on the progress on the electrochemical ammonia oxidation catalysts,the challenges and future insight on ammonia oxidation reaction are discussed and proposed.

关键词： NH3 oxidation reaction electrocatalysts green hydrogen

Cu^+-incorporated TiO_2 overlayer on Cu_2O nanowire photocathodes for enhanced photoelectrochemical conversion of CO_2 to methanol

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Journal of Energy Chemistry 2018年第1期27卷 264-270页

作者： Kangha.lee Seokwon lee Hyunjin Cho Sunil Jeong Whi Dong Kim Sooho lee Doh C.lee Department of Chemical and Biomolecular Engineering(BK21+program) KAIST Institute for the NanocenturyKorea Advanced Institute of Science and Technology(KAIST)

In this paper, we report photoelectrochemical（PEC） conversion of carbon dioxide（CO_2） using photocathodes based on Cu_2O nanowires（NWs） overcoated with Cu~＋-incorporated crystalline TiO_2（TiO_2–Cu~＋）shell. Cu_2O NW photocathodes show remanent photocurrent of 5.3% after 30 min of PEC reduction of CO_*** coating Cu_2O with TiO_2–Cu~＋ overlayer, the remanent photocurrent is 27.6%, which is an increase by5.2 fold. The charge transfer resistance of Cu_2O/TiO_2–Cu~＋ is 0.423 k/cm2, whereas Cu_2O photocathode shows resistivity of 0.781 k/cm2 under irradiation. Mott–Schottky analysis reveals that Cu~＋ species embedded in TiO_2 layer is responsible for enhanced adsorption of CO_2 on TiO_2 surface, as evidenced by the decrease of capacitance in the Helmholtz layer. On account of these electrochemical and electronic effects by the Cu~＋ species, the Faradaic efficiency（FE） of photocathodes reaches as high as 56.5% when TiO_2–Cu~＋ is added to Cu_2O, showing drastic increase from 23.6% by bare Cu_2O photocathodes.

关键词： Photoelectrochemical CO2 reductionMethanol generation Copper oxide Titanium dioxide Cu+ catalyst

NTR/NRX Define a New Thioredoxin System in the Nucleus of Arabidopsis thaliana Cells

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Molecular Plant 2014年第1期7卷 30-44页

作者： corinne Marchal Valerie Delorme-Hinoux Laetitia Bariat Wafi Siala Christophe Belin Julio Saez-Vasquez Christophe Riondet Jean-Philippe Reichheld Universite Perpignan Via Domitia CNRS Laboratoire Genome et Developpement des Plantes UMR 5096 58 Avenue Paul Alduy-Bat T F-66860 Perpignan France Pharmacologie cellulaire et moleculaire Louvain Drug Research Institute Universite catholique de Louvain Brussels Belgium

Thioredoxins （TRX） are key components of cellular redox balance, regulating many target proteins through thiol/disulfide exchange reactions. In higher plants, TRX constitute a complex multigenic family whose members have been found in almost all cellular compartments. Although chloroplastic and cytosolic TRX systems have been largely studied, the presence of a nuclear TRX system has been elusive for a long time. Nucleoredoxins （NRX） are potential nuclear TRX found in most eukaryotic organisms. In contrast to mammals, which harbor a unique NRX, angiosperms gen- erally possess multiple NRX organized in three subfamilies. Here, we show thatArabidopsis thaliana has two NRXgenes （AtNRX1 and AtNRX2）, respectively, belonging to subgroups I and III. While NRX1 harbors typical TRX active sites （WCG/ PPC）, NRX2 has atypical active sites （WCRPC and WCPPF）. Nevertheless, both NRXl and NRX2 have disulfide reduction capacities, although NRX1 alone can be reduced by the thioredoxin reductase NTRA. We also show that both NRX1 and NRX2 have a dual nuclear/cytosolic localization. Interestingly, we found that NTRA, previously identified as a cytosolic protein, is also partially localized in the nucleus, suggesting that a complete TRX system is functional in the nucleus. We show that NRX1 is mainly found as a dimer in vivo. nrxl and nrx2 knockout mutant plants exhibit no phenotypic perturbations under standard growth conditions. However, the nrxl mutant shows a reduced pollen fertility phenotype, suggesting a specific role of NRX1 at the haploid phase.

关键词： thioredoxin nucleoredoxin nucleus Arabidopsis.

Effect of processing temperatures on characteristics of surface layers of low temperature plasma nitrocarburized AISI 204Cu austenitic stainless steel

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中国有色金属学会会刊：英文版 2012年第S3期22卷 678-682页

作者： Insup lee Department of Advanced Materials Engineering Dongeui University

The influence of processing temperatures on the surface characteristics of AISI 204Cu austenitic stainless steel was investigated during a low temperature plasma *** resultant layer was a dual-layer structure,which comprises a N-enriched layer on the top of C-enriched *** surface hardness and the layer thickness increase up to about HV 0.05 1000 and 20μm with increasing *** specimen treated at 400°C shows a much enhanced corrosion resistance compared to the untreated steel.A loss in corrosion resistance was observed for specimens treated at temperatures above 430°C due to the formation of Cr2N.

关键词： low temperature plasma nitrocarburizing corrosion resistance expanded austenite AISI 204Cu stainless steel hardness.