检索结果-南通市图书馆

Spindle-like FeySs/N-doped carbon nanohybrids for high-performance sodium ion battery anodes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2019年第3期12卷 695-700页

作者： Aihua Jin Mi-Ju Kim Kug-seung Lee seung-ho yu yung-Eun Sung Center for Nanoparticle Research Institute for Basic Science (IBS) Seoul 08826 Republic of Korea School cf Chemical and Biological Engineering Seoul National University Seoul 08826 Republic cf Korea Beamline Department Pohang Accelerator Laboratory (PAL) Pohang 790-784 Republic of Korea Department of Chemistry and Chemical Biology Cornell University Ithaca New York 14853 USA

Iron sulfides have bee n con sidered as one of the most promising can didates for sodium ion battery anode materials due to their high theoretical capacity and low cost. I n this work, spin dle-like Fe7S8 with n itroge rvdoped carb on (FeiS/N-C) nano hybrids are successfully syn thesized via a solvothermal method by sulfidation iron-based metal organic framework (FeMOF). As sodium ion battery an odes, FeySs/N-C nano hybrids exhibit high reversible capacity of 450.8 mAh g-1 at 200 mA·g^-1, and 406.7 mAh·g^-1 at 500 mA·g^-1 even after 500 cycles. They also show excellent rate properties and delivering the capacity of 327.8 mAh·g^-1 at a very high current density of 3.2 A·g^-1. These outstanding electrochemical performa nces can be attributed to the unique structure of Fe7S8/ N-C nan ohybrids. The nano scale dime nsion in their size can be ben eficial for facile ion and electro n tran sports. Furthermore, the stable n itroge n doped carb on frameworks can also improve electrical conductivity and relieve the problems related to volume expansion. X-ray absorption spectroscopy and X-ray photoelectron spectroscopy analyses have been performed to study reactions occurred in spindle-like FeySs/N-C nanohybrid electrode at both bulk and surface.

关键词： sodium ion batteries iron sulfides metal organic frameworks X-ray absorption spectroscopy X-ray photoelectron spectroscopy

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

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 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

Unveiling the role of Ni in Ru-Ni oxide for oxygen evolution: Lattice oxygen participation enhanced by structural distortion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2023年第2期77卷 54-61,I0003页

作者： Young-Jin Ko Man ho Han Chulwan Lim seung-ho yu Chang Hyuck Choi Byoung Koun Min Jae-Young Choi Woong Hee Lee Hyung-Suk Oh Clean Energy Research Center Korea Institute of Science and Technology(KIST)Hwarang-ro 14-gil 5Seongbuk-guSeoul 02792Republic of Korea Department of Chemical and Biological Engineering Korea University145Anam-roSeongbuk-guSeoul 02841Republic of Korea Department of Chemistry Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea National Agenda Research Division Korea Institute of Science and Technology(KIST)Hwarang-ro 14-gil 5Seonbuk-guSeoul 02792Republic of Korea Graduate School of Energy and Environment(KU-KIST Green School) Korea University145 Anam-roSeongbuk-guSeoul 02841Republic of Korea School of Advanced Materials Science&Engineering Sungkyunkwan University(SKKU)Suwon 16419Republic of Korea KIST-SKKU Carbon-Neutral Research Center Sungkyunkwan University(SKKU)Suwon 16419Republic of Korea

Introducing Ni in Ru oxide is a promising approach to enhance the catalytic activity for the oxygen evolution reaction(OER).however,the role of Ni(which has a poor intrinsic activity)is not fully ***,a Ru NiO_(x)electrode fabricated via a modified dip coating method exhibited excellent OER performance in acidic media,and neutral media for CO_(2)reduction *** combined in-situ/operando X-ray absorption near-edge structure and on-line inductively coupled plasma mass spectrometry studies to unveil the role of the Ni introduced in the Ru *** propose that the Ni not only transforms the electronic structure of the Ru oxide,but also produces a large number of oxygen vacancies by distorting the oxygen lattice structure at low overpotentials,increasing the participation of lattice oxygen for *** work demonstrates the real behavior of bimetallic oxide materials under applied potentials and provides new insights into the development of efficient electrocatalysts.

关键词： Oxygen evolution reaction Ru electrode Ni electrode Oxygen vacancies In-situ/Operando studies

Electrochemical determination of the degree of atomic surface roughness in Pt-Ni alloy nanocatalysts for oxygen reduction reaction

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2021年第2期3卷 375-383页

作者： Tae-Yeol Jeon seung-ho yu Sung J.Yoo Hee-Young Park Sang-Kyung Kim Beamline Department Pohang Accelerator Laboratory(PAL)PohangRepublic of Korea Department of Chemical and Biological Engineering Korea UniversitySeoulRepublic of Korea Fuel Cell Center Korea Institute of Science and Technology(KIST)SeoulRepublic of Korea Fuel Cell Research Center Korea Institute of Energy Research(KIER)DaejeonRepublic of Korea

Pt-Ni alloy nanocrystals with Pt-enriched shells were prepared by selective etching of surface Ni using sulfuric acid and *** changes in the electronic and geometric structure of the alloy nanoparticles at the surface were elucidated from the electrochemical surface area,the potential of zero total charge(PZTC),and relative surface roughness,which were determined from CO-and CO_(2)-displacement experiments before and after 3000 potential cycles under oxygen reduction reaction *** the highest activity and durability were achieved in hydroquinone-treated Pt–Ni,sulfuric acidtreated one showed the lower activity and durability despite its higher surface Pt concentration and alloying *** PZTC and QCO_(2)/QCO ratio(desorption charge of reductively adsorbed CO_(2) normalized by COad-stripping charge)depend on surface *** particular,QCO_(2)/QCO ratio change better reflects the roughness on an atomic scale,and PZTC is also affected by the electronic modification of Pt atoms in surface *** this study,a comparative study is presented to find a relationship between surface structure and electrochemical properties,which reveals that surface roughness plays a critical role to improve the electrochemical performance of Pt-Ni alloy catalysts with Pt-rich surfaces.

关键词： electrocatalyst fuel cell oxygen reduction reaction Pt-Ni surface roughness

Iron sulfides with dopamine-derived carbon coating as superior performance anodes for sodium-ion batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2019年第10期12卷 2609-2613页

作者： Aihua Jin seung-ho yu Jae-Hyuk Park Seok Mun Kang Mi-Ju Kim Tae-Yeol Jeon Junyoung Mun yung-Eun Sung Center for Nanoparticle Research Institute for Basic Science(IBS)Seoul 08826Republic of Korea School of Chemical and Biological Engineering Seoul National UniversitySeoul 08826Republic of Korea Department of Chemical and Biological Engineering Korea University145 Anatn-roSeongbtik-guSeoul 02841Republic cf Korea Beamline Department Pohang Accelerator Laboratory(PAL)Pohang 37673Republic of Korea Department of Energy and Chemical Engineering Incheon National University12-1Songdo-dong Yeonsu-guIncheon 22012Republic of Korea

High energy ball-milled iron sulfides with thin carb on layer coati ng(BM-FeS/C composites)were prepared by the simple and econo mical ***-milled process,followed by carb on coati ng,reduced the particle size and increased the electrical con *** n employed as sodium-ion battery ano des,BM?F eS/C composites showed extremely high electrochemical performa nee with reversible specific capacity of 589.8 mAh·g^-1 after 100 cycles at a current density of 100 mA·g^-*** also exhibited superior rate capabilities of 375.9 mAh·g^-1 even at 3.2 Ag^1 and 423.6 mAh·g^-1 at 1.5 Ag_1.X-ray absorptio n near edge structure an alysis con firmed the electrochemical pathway for con version reaction of BM-FeS/C composites.

关键词： sodium-ion batteries iron sulfides high energy ball-milling dopamine X-ray absorption near edge structure

Influence of sulfides on the tribological properties of composites produced by pulse electric current sintering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2014年第1期21卷 95-103页

作者： seung ho Kim Department of Electronics Engineering Dankook University

Self-lubricating A1203-15wt% ZrO2 composites with sulfides, such as molybdenum disulfide （MoS2） and tungsten disulfide （WSz） serving as solid lubricants, were fabricated by using the pulse electric current sintering （PECS） technique. The coefficient of friction （COF） of the A1203-15wt% ZrO2 composite without/with sulfides was in the range of 0.37-0.48 and 0.27-0.49, respectively. As the amoant of sul- fides increased, the COF and the wear rate decreased. The reduction in COF and wear rate of the sulfide-containing composite is caused by a reduction in shear stresses between the specimen and the tribological medium due to the formation of a lubricating film resulting from the lamellar structure of sulfides located on the worn surface.

关键词： ceramic composites coefficient of friction solid lubricants sulfides wear of materials

Depth perception on fundus images using a single-channel stereomicroscopy

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Innovative Optical Health Sciences 2021年第3期4卷 68-76页

作者： Edalat Radfar Hyunseon yu Tien Son ho seung ho Choi Byungjo Jung Department of Biomedical Engineering Yonsei University Wonju-siGangwon-do 26493 Republic of Korea Research Center for Science and Technology in Medicine Tehran University of Medical Sciences Tehran 14185-615Iran Institute of Metabolism and Systems Research University of Birmingham Edgbaston Birmingham B152TTUK

Typical fundus photography produces a two-dimensional *** makes it difficult to observe the microvascular and neural abnormalities,because the depth of the image is *** provide depth appreciation,we develop a single-channel stereoscopic fundus video imaging sys-tem based on a rotating *** respect to the pupil center,the rotating refractor laterally displaces the optical path and the *** allows standard monocular fundus cameras to generate stereo-parallax and image disparity through sequential image *** opti-mize our imaging system,characterize the stereo-base,and image an eyeball model and a rabbit *** virtual realities are considered,our imaging system can be a simple yet efficient technique to provide depth perception in a virtual space that allows users to perceive abnor-malities in the eye fundus.

关键词： Imaging systems ophthalmic optics and devices refraction vision-binocular and stereopsis

Photocatalytic decomposition of mobile-source related pollutants using a continuous-flow reactor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第3期22卷 460-466页

作者： Wan-Kuen Jo seung-ho Shin Department of Environmental Engineering Kyungpook National University

This study evaluated the application of a continuous-flow photocatalytic reactor for the control of two mobile-derived pollutants, methyl-tertiary butyl ether （MTBE） and naphthalene, present at in-vehicle levels. Variables tested for this study included the hydraulic diameter （HD）, stream flow rate （SFR）, relative humidity （RH）, and feeding type （FT）. The fixed parameters included contaminant concentration, ultraviolet light source, and the weight of TiO2. In all experimental conditions the adsorption process reached equilibrium within 30 to 180 min for the target compounds, and the outlet concentrations of the photocatalytic oxidation （PCO） reactor while operating reached a steady state within 60 to 180 min. The degradation of the target compounds was dependent on RH, HD, FT, or SFR. The PCO system exhibited high degradation （up to nearly 100% for certain conditions） and mineralization efficiencies of target compounds, suggesting that this system can effiectively be employed to improve indoor air quality. Moreover, it was confirmed that trichloroethylene at urban-ambient level also could enhance the degradation efficiency of naphthalene when applying the PCO technology inside vehicles.

关键词： in-vehicle level methyl-tertiary butyl ether naphthalene trichloroethylene

Comparison of different nutritional assessments in detecting malnutrition among gastric cancer patients

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第26期16卷 3310-3317页

作者： seung Wan Ryu In ho Kim Department of Surgery and Division of Gastrointestinal Surgery The Keimyung University School of Medicine Daegu 700-712 South Korea

AIM: To evaluate the prevalence of preoperative and postoperative malnutrition and the relationships between objective and subjective nutritional assessment of gastric cancer patients. METhoDS: From October 2005 to July 2006, we studied 80 patients with no evidence of recurrent disease and no loss to follow-up after curative surgery for gastric cancer. In this group, 9 patients underwent total gastrectomy and 71 patients subtotal gastrectomy. At admission, 6 and 12 mo after surgery, the patients were assessed on the subjective global assessment (SGA), nutritional risk screening (NRS-2002), nutritional risk index (NRI) and by anthropometric measurements and laboratory data. Differences between the independent groups were assessed with the Student's t test and oneway analysis of variance. Spearman's rank correlation coefficients were calculated to evaluate the association between the scores and variables. RESULTS: The prevalence of malnutrition at admissionwas 31% by SGA and 43% by NRS-2002. At admission, the anthropometric data were lower in the malnourished groups defined by the SGA and NRS-2002 assessments, but did not differ between the groups using the NRI assessment. Body weight (BW), body mass index (BMI), triceps skin fold and midarm circumference were significantly reduced, but the total lymphocyte count, albumin, protein, cholesterol and serum iron levels did not decrease during the postoperative period. Six months after surgery, there was a good correlation between the nutritional assessment tools (SGA and NRS-2002) and the other nutritional measurement tools (BW, BMI, and anthropometric measurements). however, 12 mo after surgery, most patients who were assessed as malnourished by SGA and NRS-2002 had returned to their preoperative status, although their BW, BMI, and anthropometric measurements still indicated a malnourished status. CONCLUSION: A combination of objective and subjective assessments is needed for the early detection of the nutritional status

关键词： Gastrectomy Malnutrition Nutritional assessment Nutritional risk screening Postoperative follow up Subjective global assessment