检索结果-南通市图书馆

Discharge Characteristics of Large-Area High-Power RF Ion Source for Positive and Negative Neutral Beam Injectors

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2016年第12期18卷 1220-1224页

作者： Doo-Hee CHANG seung ho jeong Min PARK Tae-Seong KIM Bong-Ki JUNG Kwang Won LEE Sang Ryul IN Division of Nuclear Fusion Engineering & Technology Development Korea Atomic Energy Research Institute

A large-area high-power radio-frequency（RF） driven ion source was developed for positive and negative neutral beam injectors at the Korea Atomic Energy Research Institute（KAERI）. The RF ion source consists of a driver region, including a helical antenna and a discharge chamber, and an expansion region. RF power can be transferred at up to 10 kW with a fixed frequency of 2 MHz through an optimized RF matching system. An actively water-cooled Faraday shield is located inside the driver region of the ion source for the stable and steady-state operations of high-power RF discharge. Plasma ignition of the ion source is initiated by the injection of argongas without a starter-filament heating, and the argon-gas is then slowly exchanged by the injection of hydrogen-gas to produce pure hydrogen plasmas. The uniformities of the plasma parameter,such as a plasma density and an electron temperature, are measured at the lowest area of the driver region using two RF-compensated electrostatic probes along the direction of the shortand long-dimensions of the driver region. The plasma parameters will be compared with those obtained at the lowest area of the expansion bucket to analyze the plasma expansion properties from the driver region to the expansion region.

关键词： neutral beam injector RF ion source plasma ignition power loading plasma parameters

Electrochemical biosensors for point-of-care testing

在线全文

学校读者我要写书评

暂无评论

Bio-Design and Manufacturing 2024年第4期7卷 548-565页

作者： Jinsol Kim Juho jeong seung Hwan Ko Department of Mechanical Engineering Seoul National UniversitySeoul 08826Republic of Korea Institute of Advanced Machinery and Design(SNU-IAMD) Seoul National UniversitySeoul 08826Republic of Korea

Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical *** has been less common in the recent past due to a lack of portable medical devices capable of facilitating effective medical ***,recent growth has occurred in this field due to advances in diagnostic technologies,device miniaturization,and progress in wearable *** these developments,electrochemical sensors have attracted interest in the POCT field due to their high sensitivity,compact size,and *** are used in various applications,from disease diagnosis to health status *** this paper we explore recent advancements in electrochemical sensors,the methods of fabricating them,and the various types of sensing mechanisms that can be ***,we delve into methods for immobilizing specific biorecognition elements,including enzymes,antibodies,and aptamers,onto electrode surfaces and how these sensors are used in real-world POCT settings.

关键词： Point-of-care testing(POCT) Electrochemical sensor Enzyme Antibody Health care

Direct 4D printing of functionally graded hydrogel networks for biodegradable,untethered,and multimorphic soft robots

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第2期6卷 407-416页

作者： Soo Young Cho Dong Hae ho Sae Byeok Jo jeong ho Cho Department of Chemical and Biomolecular Engineering Yonsei UniversitySeoul 03722Republic of Korea Department of Mechanical Engineering Virginia TechBlacksburgVA 24061United States of America School of Chemical Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon 16419Republic of Korea

Recent advances in functionally graded additive manufacturing(FGAM)technology have enabled the seamless hybridization of multiple functionalities in a single *** robotics can become one of the largest beneficiaries of these advances,through the design of a facile four-dimensional(4D)FGAM process that can grant an intelligent stimuli-responsive mechanical functionality to the printed ***,we present a simple binder jetting approach for the 4D printing of functionally graded porous multi-materials(FGMM)by introducing rationally designed graded multiphase feeder *** graded cross-linking agents gradually form stable porous network structures within aqueous polymer particles,enabling programmable hygroscopic deformation without complex mechanical ***,a systematic bed design incorporating additional functional agents enables a multi-stimuli-responsive and untethered soft robot with stark stimulus *** biodegradability of the proposed 4D-printed soft robot further ensures the sustainability of our approach,with immediate degradation rates of 96.6%within 72 *** proposed 4D printing concept for FGMMs can create new opportunities for intelligent and sustainable additive manufacturing in soft robotics.

关键词： intelligent and sustainable additive manufacturing multi-material four-dimensional printing untethered soft robot multi-stimuli-responsive soft robot biodegradable soft robotics

Long cycle-life aqueous Zn battery enabled by facile carbon nanotube coating on Cu current collector

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第6期6卷 151-164页

作者： Beom-Keun Cho Sung-ho Huh So Hee Kim seungho Yu Jong-Seong Bae Jung-Keun Yoo seung-ho Yu Department of Chemical and Biological Engineering Korea UniversitySeoulRepublic of Korea Advanced Analysis Center Korea Institute of Science and Technology(KIST)SeoulRepublic of Korea Energy Storage Research Center Korea Institute of Science and Technology(KIST)SeoulRepublic of Korea KIST School Division of Energy and Environment TechnologyKorea University of Science and TechnologySeoulRepublic of Korea Busan Center Korea Basic Science Institute(KBSI)BusanRepublic of Korea Carbon Composites Department Composites Research DivisionKorea Institute of Materials Science(KIMS)ChangwonRepublic of Korea

As an alternative to Li-ion batteries,aqueous Zn batteries have gained attention due to the abundance of Zn metal,low reduction potential(-0.76 V *** hydrogen electrode),and high theoretical capacity(820 mAh g^(-1))of multivalent Zn2+***,the growth of Zn dendrites and the formation of irreversible surface reaction byproducts pose challenges for ensuring a long battery lifespan and ***,the Cu foil coated with a single-walled carbon nanotube(SWCNT)layer using a facile doctor blade casting method is *** SWCNT-coated Cu foil demonstrates a significantly longer battery lifespan compared to the bare Cu in the half-cell *** operando optical microscopy imaging,we are able to provide intuitive evidence that Zn deposition occurs between the carbon nanotube(CNT)coating and Cu substrate,in agreement with the computational ***,with various imaging techniques,the flat morphology and homogeneous distribution of Zn beneath the SWCNT layer are *** addition,the full-cell using CNT-coated Cu exhibits a long cycle life compared to the control group,thereby demonstrating improved electrochemical performance with limited Zn for the cycling process.

关键词： aqueous Zn battery carbon nanotube operando imaging surface coating

Defect Engineering in Earth-Abundant Cu_(2)ZnSnSe_(4) Absorber Using Efficient Alkali Doping for Flexible and Tandem Solar Cell Applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第2期7卷 249-256页

作者： Muhammad Rehan Ara Cho Inyoung jeong Kihwan Kim Asmat Ullah Jun-Sik Cho Joo Hyung Park Yunae Jo Sung Jun hong seung Kyu Ahn SeJin Ahn Jae ho Yun Jihye Gwak Donghyeop Shin Photovoltaics Research Department Korea Institute of Energy Research(KIER)152-Gajeong-roYuseong-guDaejeon 34129Korea Department of Renewable Energy Engineering University of Science and Technology(UST)217-Gajeong-roYuseong-guDaejeon 34113Korea Korea Institute of Energy Technology(KENTECH) 50772 Ujeong-roNaju Jeonnam 58217Korea

To demonstrate flexible and tandem device applications,a low-temperature Cu_(2)ZnSnSe_(4)(CZTSe)deposition process,combined with efficient alkali doping,was ***,high-quality CZTSe films were grown at 480℃by a single co-evaporation,which is applicable to polyimide(PI)*** of the alkali-free substrate,Na and K alkali doping were systematically studied and optimized to precisely control the alkali distribution in *** bulk defect density was significantly reduced by suppression of deep acceptor states after the(NaF+KF)*** the low-temperature deposition with(NaF+KF)PDTs,the CZTSe device on glass yields the best efficiency of 8.1%with an improved Voc deficit of 646 *** developed deposition technologies have been applied to *** the first time,we report the highest efficiency of 6.92%for flexible CZTSe solar cells on ***,CZTSe devices were utilized as bottom cells to fabricate four-terminal CZTSe/perovskite tandem cells because of a low bandgap of CZTSe(~1.0 eV)so that the tandem cell yielded an efficiency of 20%.The obtained results show that CZTSe solar cells prepared by a low-temperature process with in-situ alkali doping can be utilized for flexible thin-film solar cells as well as tandem device applications.

关键词： alkali doping Earth-abundant Cu_(2)ZnSnSe_(4) flexible solar cells four-terminal tandem cells low-temperature process

Double-chambered left ventricle with a thrombus in an asymptomatic patient:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第2期12卷 460-465页

作者： Narae Kim In-ho Yang Hui-jeong Hwang Il-Suk Sohn Department of Medicine Kyung Hee UniversitySeoul 02447South Korea Department of Cardiology Kyung Hee University Hospital at GangdongSeoul 05278South Korea

BACKGROUND Double-chambered left ventricle(DCLV)is an extremely rare congenital disease in which the left ventricle(LV)is divided by abnormal muscle *** to its rarity,there is a lack of data on the disease,including its diagnosis,treatment,and ***,we report a case in which DCLV was diagnosed and followed *** SUMMARY A 45-year-old man presented to our hospital due to abnormal findings on an electrocardiogram recorded during a health *** had no specific cardiac symptoms,comorbidities or relevant past medical *** revealed that the LV was divided into two by muscle *** were no findings of ischemia on coronary angiography and coronary computed tomography angiography performed to exclude differential *** comprehensive analysis of the images,DCLV was *** it seemed to be asymptomatic DCLV,we decided the patient was to be observed without administering any ***,follow-up echocardiography revealed a thrombus in the accessory chamber(AC).Anticoagulant medication was initiated,the thrombus resolved,and the patient is currently undergoing follow-up without any specific *** Asymptomatic,uncomplicated DCLV was diagnosed through multimodal imaging;however,a thrombus in the AC occurred during the *** findings highlight that multimodal imaging is essential in diagnosing DCLV,and that anticoagulation is important in its management.

关键词： Double-chambered left ventricle Congenital heart disease Left ventricular aneurysm Echocardiography Coronary computed tomography angiography Contrast echocardiography Case report

Fine-tuning electronic structure of N-doped graphitic carbon-supported Co-and Fe-incorporated Mo_(2)C to achieve ultrahigh electrochemical water oxidation activity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2024年第7期6卷 134-149页

作者： Md.Selim Arif Sher Shah Hyeonjung Jung Vinod K.Paidi Kug-seung Lee jeong Woo Han Jong Hyeok Park Department of Chemical and Biomolecular Engineering Yonsei UniversitySeoulRepublic of Korea Department of Chemistry University of North BengalRaja RammohunpurDarjeelingWest BengalIndia Department of Materials Science and Engineering Research Institute of Advanced MaterialsSeoul National UniversitySeoulRepublic of Korea Pohang Accelerator Laboratory Beamline DivisionPohangRepublic of Korea European Synchrotron Radiation Facility France

Mo_(2)C is an excellent electrocatalyst for hydrogen evolution reaction(HER).however,Mo_(2)C is a poor electrocatalyst for oxygen evolution reaction(OER).Herein,two different elements,namely Co and Fe,are incorporated in Mo_(2)C that,therefore,has a finely tuned electronic structure,which is not achievable by incorporation of any one of the ***,the resulting electrocatalyst Co_(0.8)Fe_(0.2)-Mo_(2)C-80 displayed excellent OER catalytic performance,which is evidenced by a low overpotential of 214.0(and 246.5)mV to attain a current density of 10(and 50)mA cm^(-2),an ultralow Tafel slope of 38.4 mV dec^(-1),and longterm stability in alkaline *** data demonstrates that Co_(0.8)Fe_(0.2)-Mo_(2)C-80 requires the lowest overpotential(1.00 V)for OER and Co centers to be the active *** ultrahigh catalytic performance of the electrocatalyst is attributed to the excellent intrinsic catalytic activity due to high Brunauer-Emmett-Teller specific surface area,large electrochemically active surface area,small Tafel slope,and low chargetransfer resistance.

关键词： fine-tuning electronic structures heteronanostructures Mo_(2)C multimetal(Co/Fe) oxygen evolution reaction

Tailoring local structures of atomically dispersed copper sites for highly selective CO_(2) electroreduction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2024年第4期6卷 79-90页

作者： Kyung‐Jong Noh Byoung Joon Park Ying Wang Yejung Choi Sang‐hoon You Yong‐Tae Kim Kug‐seung Lee jeong Woo Han Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)PohangGyeongbukRepublic of Korea Department of Materials Science and Engineering Pohang University of Science and Technology(POSTECH)PohangGyeongbukRepublic of Korea Pohang Accelerator Laboratory(PAL) Beamline DivisionPohangGyeongbukRepublic of Korea

Atomically‐dispersed copper sites coordinated with nitrogen‐doped carbon(Cu–N–C)can provide novel possibilities to enable highly selective and active electrochemical CO_(2) reduction ***,the construction of optimal local electronic structures for nitrogen‐coordinated Cu sites(Cu–N_(4))on carbon remains ***,we synthesized the Cu–N–C catalysts with atomically‐dispersed edge‐hosted Cu–N_(4) sites(Cu–N_(4)C_(8))located in a micropore between two graphitic sheets via a facile method to control the concentration of metal ***‐hosted Cu–N_(4)C_(8) catalysts outperformed the previously reported M–N–C catalysts for CO_(2)‐to‐CO conversion,achieving a maximum CO Faradaic efficiency(FECO)of 96%,a CO current density of–8.97 mA cm^(–2) at–0.8 V versus reversible hydrogen electrode(RHE),and over FECO of 90%from–0.6 to–1.0 V versus *** studies revealed that the micropore of the graphitic layer in edge‐hosted Cu–N_(4)C_(8) sites causes the d‐orbital energy level of the Cu atom to shift upward,which in return decreases the occupancy of antibonding states in the*COOH *** research suggests new insights into tailoring the locally coordinated structure of the electrocatalyst at the atomic scale to achieve highly selective electrocatalytic reactions.

关键词： atomic local structure density functional theory electrochemical CO_(2)reduction metal nitrogen‐doped carbon single‐atom catalyst

Trifunctional robust electrocatalysts based on 3D Fe/N-doped carbon nanocubes encapsulating Co4N nanoparticles for efficient battery-powered water electrolyzers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2024年第6期6卷 124-139页

作者： Hyung Wook Choi hongdae Lee Jun Lu Seok Bin Kwon Dong In jeong Beum Jin Park Jiwon Kim Bong Kyun Kang Gun Jang Dae ho Yoon ho Seok Park SKKU Advanced Institute of Nano Technology(SAINT) Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea School of Chemical Engineering Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea School of Advanced Materials Science and Engineering Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea Department of Electronic Materials Devicesand Equipment EngineeringSoonchunhyang UniversityAsan CityChungnamRepublic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea Department of Health Sciences and Technology Samsung Advanced Institute for Health Sciences and Technology(SAIHST)Sungkyunkwan UniversitySuwonRepublic of Korea

Herein,we have designed a highly active and robust trifunctional electrocatalyst derived from Prussian blue analogs,where Co_(4)N nanoparticles are encapsulated by Fe embedded in N-doped carbon nanocubes to synthesize hierarchically structured Co_(4)N@Fe/N-C for rechargeable zinc-air batteries and overall water-splitting *** confirmed by theoretical and experimental results,the high intrinsic oxygen reduction reaction,oxygen evolution reaction,and hydrogen evolution reaction activities of Co_(4)N@Fe/N-C were attributed to the formation of the heterointerface and the modulated local electronic ***,Co_(4)N@Fe/N-C induced improvement in these trifunctional electrocatalytic activities owing to the hierarchical hollow nanocube structure,uniform distribution of Co_(4)N,and conductive encapsulation by Fe/***,the rechargeable zinc-air battery with Co_(4)N@Fe/N-C delivers a high specific capacity of 789.9 mAh g^(-1) and stable voltage profiles over 500 ***,the overall water electrolyzer with Co_(4)N@Fe/N-C achieved better durability and rate performance than that with the Pt/C and IrO2 catalysts,delivering a high Faradaic efficiency of 96.4%.Along with the great potential of the integrated water electrolyzer powered by a zinc-air battery for practical applications,therefore,the mechanistic understanding and active site identification provide valuable insights into the rational design of advanced multifunctional electrocatalysts for energy storage and conversion.

关键词： battery-powered electrolyzers hierarchical structure Prussian blue analog trifunctional electrocatalyst zinc-air battery