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100 W-class green hydrogen production from ammonia at a dual-layer electrode containing a Pt-Ir catalyst for an alkaline electrolytic process
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作者 Donghyun Yoon Sunki Chung +2 位作者 Minjun Choi Eunhyeok Yang Jaeyoung Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期352-360,I0009,共10页
Ammonia allows storage and transport of hydrogen over long distances and is an attractive potential hydrogen carrier.Electrochemical decomposition has recently been used for the conversion of ammonia to hydrogen and i... Ammonia allows storage and transport of hydrogen over long distances and is an attractive potential hydrogen carrier.Electrochemical decomposition has recently been used for the conversion of ammonia to hydrogen and is regarded as a future technology for production of CO_(2)-free pure hydrogen.Herein,a heterostructural Pt-Ir dual-layer electrode is developed and shown to achieve successful long-term operation in an ammonia electrolyzer with an anion exchange membrane(AEM).This electrolyzer consisted of eight membra ne electrode assemblies(MEAs)with a total geometric area of 200 cm~2 on the anode side,which resulted in a hydrogen production rate of 25 L h~(-1).We observed the degradation in MEA performance attributed to changes in the anode catalyst layer during hydrogen production via ammonia electrolysis.Furthermore,we demonstrated the relationship between the ammonia oxidation reaction(AOR)and the oxygen evolution reaction(OER). 展开更多
关键词 Ammonia oxidation Dual-layer catalyst Green hydrogen Electrolytic process Oxygen evolution reaction
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Anode surface engineering of zinc-ion batteries using tellurium nanobelt as a protective layer for enhancing energy storage performance
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作者 Soobeom Lee Yeonjin Je +7 位作者 Boeun Seok Hyun Tae Kim Yong-Ryun Jo Soong Ju Oh Byoungyong Im Dae Guen Kim Sang-Soo Chee Geon-Hyoung An 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期113-123,共11页
Over the years,zinc-ion batteries(ZIBs)have attracted attention as a promising next-generation energy storage technology because of their excellent safety,long cycling performance,eco-friendliness,and high-power densi... Over the years,zinc-ion batteries(ZIBs)have attracted attention as a promising next-generation energy storage technology because of their excellent safety,long cycling performance,eco-friendliness,and high-power density.However,issues,such as the corrosion and dissolution of the Zn anode,limited wet-tability,and lack of sufficient nucleation sites for Zn plating,have limited their practical application.The introduction of a protective layer comprising of tellurium(Te)nanobelts onto the surface of Zn anode has emerged as a promising approach to overcome these limitations and improve the electrochemical behav-ior by enhancing the safety and wettability of ZIBs,as well as providing numerous nucleation sites for Zn plating.In the presence of a Te-based protective layer,the energy power density of the surface-engineered Zn anode improved significantly(ranging from 310 to 144 W h kg^(-1),over a power density range of 270 to 1,800 W kg^(-1)),and the lifespan capability was extended.These results demonstrate that the proposed strategy of employing Te nanobelts as a protective layer holds great promise for enhancing the energy storage performance of zIBs,making them even more attractive as a viable energy storage solution forthefuture. 展开更多
关键词 Zn ion battery ANODE Protective layer TELLURIUM NANOBELT
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Recent developments in application of single-cell RNA sequencing in the tumour immune microenvironment and cancer therapy 被引量:1
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作者 Pei-Heng Li Xiang-Yu Kong +6 位作者 Ya-Zhou He Yi Liu Xi Peng Zhi‑Hui Li Heng Xu Han Luo Jihwan Park 《Military Medical Research》 SCIE CAS CSCD 2023年第3期383-402,共20页
The advent of single-cell RNA sequencing(scRNA-seq)has provided insight into the tumour immune microenvironment(TIME).This review focuses on the application of scRNA-seq in investigation of the TIME.Over time,scRNA-se... The advent of single-cell RNA sequencing(scRNA-seq)has provided insight into the tumour immune microenvironment(TIME).This review focuses on the application of scRNA-seq in investigation of the TIME.Over time,scRNA-seq methods have evolved,and components of the TIME have been deciphered with high resolution.In this review,we first introduced the principle of scRNA-seq and compared different sequencing approaches.Novel cell types in the TIME,a continuous transitional state,and mutual intercommunication among TIME components present potential targets for prognosis prediction and treatment in cancer.Thus,we concluded novel cell clusters of cancerassociated fibroblasts(CAFs),T cells,tumour-associated macrophages(TAMs)and dendritic cells(DCs)discovered after the application of scRNA-seq in TIME.We also proposed the development of TAMs and exhausted T cells,as well as the possible targets to interrupt the process.In addition,the therapeutic interventions based on cellular interactions in TIME were also summarized.For decades,quantification of the TIME components has been adopted in clinical practice to predict patient survival and response to therapy and is expected to play an important role in the precise treatment of cancer.Summarizing the current findings,we believe that advances in technology and wide application of single-cell analysis can lead to the discovery of novel perspectives on cancer therapy,which can subsequently be implemented in the clinic.Finally,we propose some future directions in the field of TIME studies that can be aided by scRNA-seq technology. 展开更多
关键词 Single-cell RNA sequencing(scRNA-seq) Tumour immune microenvironment(TIME) TRAJECTORY Cellular interactions Therapeutic targets
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A conformal titanyl phosphate amorphous overlayer for enhancing photoelectrochemical hydrogen peroxide production
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作者 Jaekyum Kim Young Eun Kim +8 位作者 Minyeong Je Won Tae Hong Chang-Lyoul Lee Tae-Hoon Kim Sung Min Cho Chang Hyuck Choi Heechae Choi Woo-Seok Choe Jung Kyu Kim 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第11期399-408,I0009,共11页
Photoelectrochemical(PEC)H_(2)O_(2)production through water oxidation reaction(WOR)is a promising strategy,however,designing highly efficient and selective photoanode materials remains challenging due to competitive r... Photoelectrochemical(PEC)H_(2)O_(2)production through water oxidation reaction(WOR)is a promising strategy,however,designing highly efficient and selective photoanode materials remains challenging due to competitive reaction pathways.Here,for highly enhanced PEC H_(2)O_(2)production,we present a conformal amorphous titanyl phosphate(a-TP)overlayer on nanoparticulate TiO_(2)surfaces,achieved via lysozyme-molded in-situ surface reforming.The a-TP overlayer modulates surface adsorption energies for reaction intermediates,favoring WOR for H_(2)O_(2)production over the competing O_(2)evolution reaction.Our density functional theory calculations reveal that a-TP/TiO_(2)exhibits a substantial energy uphill for the O·*formation pathway,which disfavors O_(2)evolution but promotes H_(2)O_(2)production.Additionally,the a-TP overlayer strengthens the built-in electric field,resulting in favorable kinetics.Consequently,a-TP/TiO_(2)exhibits 3.7-fold higher Faraday efficiency(FE)of 63%at 1.76 V vs.reversible hydrogen electrode(RHE)under 1 sun illumination,compared to bare TiO_(2)(17%),representing the highest FE among TiO_(2)-based WOR H_(2)O_(2)production systems.Employing the a-TP overlayer constitutes a promising strategy for controlling reaction pathways and achieving efficient solar-to-chemical energy conversion. 展开更多
关键词 Solar H_(2)O_(2) production In-situ surface reforming Titanyl phosphate Amorphous overlayer Reaction pathway control
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小胃肠间质瘤诊疗中国专家共识(2020年版) 被引量:34
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作者 叶颖江 +14 位作者 秦叔逵 沈琳 曹晖 李勇 何裕隆 梁寒 李健 张波 高志冬 王超 郭旭 王坚 王屹 王跃祥 张信华 《临床肿瘤学杂志》 CAS 北大核心 2020年第4期349-355,共7页
胃肠间质瘤(gastrointestinal stromal tumor,GIST)是胃肠道最常见的间叶源性肿瘤,根据发病部位、大小、核分裂象及有无破裂等,GIST的恶性潜能从极低危至高危不等。中国临床肿瘤学会胃肠间质瘤专家委员会于2008年、2011年、2013年和201... 胃肠间质瘤(gastrointestinal stromal tumor,GIST)是胃肠道最常见的间叶源性肿瘤,根据发病部位、大小、核分裂象及有无破裂等,GIST的恶性潜能从极低危至高危不等。中国临床肿瘤学会胃肠间质瘤专家委员会于2008年、2011年、2013年和2017年分别制定了中国GIST诊断和治疗的专家共识,这些共识的颁布和推广极大地规范和提高了我国GIST临床诊治水平。小GIST特指直径<2cm的GIST[1-2]。尽管大多数小GIST病例在临床上呈良性或惰性表现,但确有少数病例显示出侵袭性行为,尤其是核分裂象计数>5/5mm 2者。既往共识中有关小GIST的推荐证据较少。鉴于此,中国临床肿瘤学会胃肠间质瘤专家委员会联合中国抗癌协会胃肠间质瘤专业委员会、中国医师协会外科医师分会胃肠道间质瘤诊疗专业委员会在借鉴国内外最新研究的基础上,组织国内一批GIST治疗领域的专家,基于文献和专家经验整理了本版共识,力求能使小GIST的诊疗更加规范化和标准化。 展开更多
关键词 小胃肠间质瘤 诊断 治疗 共识
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Sunitinib for Taiwan Residents patients with gastrointestinal stromal tumor after imatinib treatment failure or intolerance 被引量:11
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作者 Yen-Yang Chen Chun-Nan Yeh +4 位作者 Chi-Tung Cheng Tsung-Wen Chen Kun-Ming Rau Yi-Yin Jan Miin-Fu Chen 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第16期2113-2119,共7页
AIM:To report preliminary results of the efficacy and safety of sunitinib in the management of Taiwan Residents gastrointestinal stromal tumors (GIST) patients facing imatinib mesylate (IM) intolerance or failure.METH... AIM:To report preliminary results of the efficacy and safety of sunitinib in the management of Taiwan Residents gastrointestinal stromal tumors (GIST) patients facing imatinib mesylate (IM) intolerance or failure.METHODS:Between 2001 and May 2010,199 Taiwan Residents patients with metastatic GIST were treated at Chang Gung Memorial Hospital.Among them,23 (11.6%) patients receiving sunitinib were investigated.RESULTS:Sixteen male and 7 female patients with a median age of 59 years (range:24-83 years) received sunitinib.Twenty-two GIST patients changed to sunitinib because of IM failure and 1 because of intolerance.The median duration of sunitinib administration was 6.0 mo (range:2-29 mo).The clinical benefit was 65.2% [2 complete response (CR),4 partial response (PR),and 9 stationary disease (SD);15/23].In 12 patients harboring mutations of the kit gene at exon 11,the clinical benefit rate (CR,PR,and SD) was 75.0% and 6 patients with tumors containing kit exon 9 mutations had a clinical benefit of 50.0% (not significant,P=0.344).The progression free survival (PFS) and overall survival (OS) did not differ between patients whose GISTs had wild type,KIT exon 9,or KIT exon 11 mutations.Hand-foot syndrome was the most common cause of grade Ⅲ adverse effect (26.1%),followed by anemia (17.4%),and neutropenia (13.0%).During the median 7.5-mo follow-up after sunitinib use,the median PFS and OS of these 23 GIST patients after sunitinib treatment were 8.4 and 14.1 mo,respectively.CONCLUSION:Sunitinib appears to be an effective treatment for Taiwan Residents with IM-resistant/intolerant GISTs and induced a sustained clinical benefit in more than 50% of Taiwan Residents advanced GIST patients. 展开更多
关键词 肿瘤患者 胃肠道 台湾地区 间质 治疗 耐受 基因突变 中位数
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Al-incorporation into Li7La3Zr2O12 solid electrolyte keeping stabilized cubic phase for all-solid-state Li batteries 被引量:4
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作者 Changbin Im Dongwon Park +1 位作者 Hosung Kim Jaeyoung Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2018年第5期1501-1508,共8页
We observe the influence of AI occupancies in Li sites on the formation process of the garnet solid elec- trolyte of Li_7La_3Zr_2O_12 (LLZO). A direct incorporation of AI is first promoted in a Li-insufficient garne... We observe the influence of AI occupancies in Li sites on the formation process of the garnet solid elec- trolyte of Li_7La_3Zr_2O_12 (LLZO). A direct incorporation of AI is first promoted in a Li-insufficient garnet solid electrolyte during the calcination process of 850 ℃ and then the cubic phase of LLZO is obtained after successive annealing step of 1000 ℃. Comparing to pristine LLZO, AI incorporated LLZO shows less formation of Li_2CO_3, keeping crystallographic and physicochemical properties. This AI incorporation im- proves both the ionic conductivity and interfacial resistance to poisoning procedure. 展开更多
关键词 Li_7La_3Zr_2O_12 AI incorporation Garnet solid electrolyte Cubic phase
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Biogeochemical cyclic activity of bacterial arsB in arsenic-contaminated mines 被引量:5
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作者 CHANG Jin-Soo KIM Kyoung-Woong 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第11期1348-1355,共8页
Biogeochemical cyclic activity of the ars (arsenic resistance system) operon is arsB influx/effux encoded by the ecological of Pseudomonas putida.This suggests that studying arsenite-oxidizing bacteria may lead to a b... Biogeochemical cyclic activity of the ars (arsenic resistance system) operon is arsB influx/effux encoded by the ecological of Pseudomonas putida.This suggests that studying arsenite-oxidizing bacteria may lead to a better understanding of molecular geomicrobiology,which can be applied to the bioremediation of arsenic-contaminated mines.This is the first report in which multiple arsB-binding mechanisms have been used on indigenous bacteria.In ArsB (strains OS-5; ABB83931; OS-19; ABB04282 and RW-28; ABB88574... 展开更多
关键词 arsenic resistance bacteria arsB influx/efflux pump arsenic resistance system (ars) biogeochemical
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3D视频生成与编码的时间一致性深度图估计(英文) 被引量:2
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作者 Sang-Beom Lee Yo-Sung Ho 《China Communications》 SCIE CSCD 2013年第5期39-49,共11页
In this paper, we propose a new algorithm for temporally consistent depth map estimation to generate three-dimensional video. The proposed algorithm adaptively computes the matching cost using a temporal weighting fun... In this paper, we propose a new algorithm for temporally consistent depth map estimation to generate three-dimensional video. The proposed algorithm adaptively computes the matching cost using a temporal weighting function, which is obtained by block-based moving object detection and motion estimation with variable block sizes. Experimental results show that the proposed algorithm improves the temporal consistency of the depth video and reduces by about 38% both the flickering artefact in the synthesized view and the number of coding bits for depth video coding. 展开更多
关键词 三维视频 运动估计 视频编码 时间 地图 3D 运动物体检测 加权函数
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碱性介质中碳纳米管FeNi复合物上电催化析氧反应(英文) 被引量:2
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作者 Xianghua An Dongyoon Shin +3 位作者 Joey D.Ocon Jae Kwang Lee Young-il Son Jaeyoung Lee 《催化学报》 SCIE CAS CSCD 北大核心 2014年第6期891-895,共5页
Non-noble metals such as Fe and Ni have comparable electrocatalytic activity and stability to that of Ir and Ru in an oxygen evolution reaction (OER). In this study, we synthesized carbon nanofibers with embedded FeNi... Non-noble metals such as Fe and Ni have comparable electrocatalytic activity and stability to that of Ir and Ru in an oxygen evolution reaction (OER). In this study, we synthesized carbon nanofibers with embedded FeNi composites (FeNi-CNFs) as OER electrocatalysts by a facile route comprising electrospinning and the pyrolysis of a mixture of metal precursors and a polymer solution. FeNi-CNFs demonstrated catalytic activity and stability that were better than that of 20 wt% Ir on Vulcan carbon black in oxidizing water to produce oxygen in an alkaline media. Physicochemical and electrochemical characterization revealed that Fe and Ni had synergistic roles that enhanced OER activity by the uniform formation and widening of pores in the carbon structure, while the CNF matrix also contributed to the increased stability of the catalyst. 展开更多
关键词 析氧反应 碱性介质 复合物 碳纳米纤维 镍铁 电催化活性 纳米碳纤维 基体
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Initialization for NMF-Based Audio Source Separation Using Priors on Encoding Vectors 被引量:1
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作者 Jaeuk Byun Jong Won Shin 《China Communications》 SCIE CSCD 2019年第9期177-186,共10页
Nonnegative matrix factorization(NMF)has shown good performances on blind audio source separation(BASS).While the NMF analysis is a non-convex optimization problem when both the basis and encoding matrices need to be ... Nonnegative matrix factorization(NMF)has shown good performances on blind audio source separation(BASS).While the NMF analysis is a non-convex optimization problem when both the basis and encoding matrices need to be estimated simultaneously,the source separation step of the NMF-based BASS with a fixed basis matrix has been considered convex.However,because the basis matrix for the BASS is typically constructed by concatenating the basis matrices trained with individual source signals,the subspace spanned by the basis vectors for one source may overlap with that for other sources.In this paper,we have shown that the resulting encoding vector is not unique when the subspaces spanned by basis vectors for the sources overlap,which implies that the initialization of the encoding vector in the source separation stage is not trivial.Furthermore,we propose a novel method to initialize the encoding vector for the separation step based on the prior model of the encoding vector.Experimental results showed that the proposed method outperformed the uniform random initialization by 1.09 and 2.21dB in the source-to-distortion ratio,and 0.20 and 0.23 in PESQ scores for supervised and semi-supervised cases,respectively. 展开更多
关键词 blind AUDIO source separation NONNEGATIVE matrix FACTORIZATION speech enhancement
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Iridium oxide fabrication and application: A review 被引量:1
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作者 Hansaem Jang Jaeyoung Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第7期152-172,I0005,共22页
Despite the scarcity and cost of iridium oxide,it is still the material of choice in numerous fields of science and applications,including capacitors,electrochromism,sensors,and various oxidation electrocatalysis(e.g.... Despite the scarcity and cost of iridium oxide,it is still the material of choice in numerous fields of science and applications,including capacitors,electrochromism,sensors,and various oxidation electrocatalysis(e.g.,chlorine evolution reaction,detoxification,and oxygen evolution reaction).Such versatility is attributed to the distinct features of iridium oxides,such as their activity,biocompatibility,conductivity,and durability.The features and properties of iridium oxides are strongly dependent on the fabrication method.In this review,methodologies relating to the synthesis and fabrication of solid-state iridium oxides have been thoroughly collected and discussed.Structuring and crystallization techniques for iridium oxides are also noted.At the end of the review,the effects of utilizing a certain fabrication method on the characteristics of the iridium oxide product are recapitulated,together with the recommended application of the product in various fields. 展开更多
关键词 Iridium oxide Iridium dioxide ELECTRODE ELECTROCATALYST ELECTROCHROMISM pH sensor Oxygen evolution reaction
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Positively charged carbon electrocatalyst for enhanced power performance of L-ascorbic acid fuel cells 被引量:1
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作者 Myounghoon Choun Hye Jin Lee Jaeyoung Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2016年第5期793-797,共5页
Carbon surface with large oxygen and carbon ratio(O/C) indicated an outstanding electro-catalytic activity toward L-ascorbic acid oxidation, compared to platinum group metals. However, interrelation of surface functio... Carbon surface with large oxygen and carbon ratio(O/C) indicated an outstanding electro-catalytic activity toward L-ascorbic acid oxidation, compared to platinum group metals. However, interrelation of surface functional groups and its electro-catalytic activity is still unclear. In this paper, we prepared different levels of oxidized carbons by a simple acid treatment and investigated the correlation between the surface oxygen functional groups of acid-treated carbon and electro-catalytic activity in an electrooxidation of L-ascorbic acid. Positively charged carbon was demonstrated by lone pair electron of oxygen from valence band spectra study. It was revealed that the positively charged carbon, especially involved in carbonyl, showed enhanced the electro-catalytic activity through both better adsorption of negatively charged reactants and lowered LUMO by electronegativity of oxygen. 展开更多
关键词 Vitamin-C electrooxidation ELECTRONEGATIVITY CARBON Atomic charge Surface oxygen
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Buffon’s Needle Algorithm to Estimate π 被引量:1
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作者 Chi-Ok Hwang Yeongwon Kim +1 位作者 Cheolgi Im Sunggeun Lee 《Applied Mathematics》 2017年第3期275-279,共5页
Buffon’s needle experiment was originally devised to get the value of π. With the advent of computers, Buffon’s needle algorithm has been used pedagogically as an example of Monte Carlo methods in introduction clas... Buffon’s needle experiment was originally devised to get the value of π. With the advent of computers, Buffon’s needle algorithm has been used pedagogically as an example of Monte Carlo methods in introduction classes, and there are many Buffon’s needle algorithm implementations available on the internet. However, for the calculation of π, the exact value of π is used in the programs for Buffon’s needle angle sampling, and hence the example is not demonstrated correctly. This brief note presents a random angle sampling algorithm for the Buffon’s needle. We then compare the Buffon’s needle and Hit-and-Miss integration algorithms using Monte Carlo laboriousness comparison, and find that the Hit-and-Miss algorithm is superior. 展开更多
关键词 Buffon’s NEEDLE MONTE Carlo ANGLE Sampling
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Selective conversion of N_(2) to NH_(3) on highly dispersed RuO_(2) using amphiphilic ionic liquid-anchored fibrous carbon structure 被引量:1
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作者 Kahyun Ham Muhammad Salman +4 位作者 Sunki Chung Minjun Choi HyungKuk Ju Hye Jin Lee Jaeyoung Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第4期474-482,共9页
Ammonia (NH_(3)) plays a key role in the agricultural fertilizer and commodity chemical industries and is useful for exploring hydrogen storage carriers.The electrochemical nitrogen reduction reaction (NRR) is receivi... Ammonia (NH_(3)) plays a key role in the agricultural fertilizer and commodity chemical industries and is useful for exploring hydrogen storage carriers.The electrochemical nitrogen reduction reaction (NRR) is receiving attention as an environmentally sustainable NH_(3) synthesis replacement for the traditional Haber–Bosch process owing to its near ambient reaction conditions (<100℃ and 1 atm).However,its NH_(3) yield and faradaic efficiency are extremely low because of the sluggish kinetics of N≡N bond dissociation and the hindrance from competitive hydrogen evolution.To overcome these challenges,we herein introduce a dual-functionalized ionic liquid (1-(4-hydroxybutyl)-3-methylimidazolium hydroxide[HOBIM]OH) for a highly dispersed ruthenium oxide electrocatalyst to achieve a biased NRR.The observed uniform distribution of RuO_(2) on the carbon fiber and increase in the surface area for N_(2) adsorption by limiting proton access can be attributed to the presence of imidazolium ions.Moreover,extensive N_(2) adsorption contributes to enhanced NRR selectivity with an NH_(3) yield of 3.0×10^(-10)mol cm^(-2)s^(-1)(91.8μg h^(-1)mg^(-1)) and a faradaic efficiency of 2.2%at-0.20 V_(RHE).We expect our observations to provide new insights into the design of effective electrode structures for electrochemical NH;synthesis. 展开更多
关键词 Ammonia synthesis Nitrogen reduction reaction Imidazolium-based ionic liquid Ruthenium oxide
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A survey of arsenic and other heavy metals in vegetation from markets or mine tailings 被引量:1
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作者 LIU Wen-ju Kim Kyoung-woong +3 位作者 ZHU Yong-guan LEE Sang-woo CHANG Pei-chun Kwak Ji-hyun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第2期287-291,共5页
This research includes two investigations. The first one is a market basket survey of the levels of arsenic (As) and trace elements in bracken fern (Pteridium aquilinum) originated from three countries: South Kor... This research includes two investigations. The first one is a market basket survey of the levels of arsenic (As) and trace elements in bracken fern (Pteridium aquilinum) originated from three countries: South Korea, China and North Korea. The results showed that the mean As concentrations in stems of samples were significantly higher than those in leaves. As concentrations in all samples did not exceed food safety limits for vegetables. Generally, concentrations of Fe, Mn, Cu and Zn in leaves were higher than those in stems. The second investigation is a survey on the levels of As and other heavy metals in vegetation in the vicinity of Myoungbong mine tailings. The results demonstrated that As, Pb and Cu concentrations and bioaccumulation factors (BCF) in seedlings of the fern(A splenium achilleifolium) were the highest, whereas Marsh horsetail(Equisetum polustre) accumulated the highest levels of Zn. Concentrations of As, Pb, Zn and Cu in vegetable-cress (Lepidium sativum) and the edible herb-aromatic madder (Elasholtzia splendens) were higher than food safety limits. Therefore, a risk assessment of As and other heavy metals in vegetables and herbs on local human health should be conducted in the future. 展开更多
关键词 ARSENIC heavy metals FERNS bioaccumulation factors
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Electro-oxidation of mixed reactants of ethanol and formate on Pd/C in alkaline fuel cells
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作者 Myounghoon Choun Jaeyoung Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2016年第4期683-690,共8页
Direct ethanol fuel cells have attracted attention as an alternative energy technology due to several advantages such as high theoretical energy density and abundant supply of ethanol.In spite of the advantages,commer... Direct ethanol fuel cells have attracted attention as an alternative energy technology due to several advantages such as high theoretical energy density and abundant supply of ethanol.In spite of the advantages,commercialization of direct ethanol fuel cells is hampered by the relatively low performance caused by its slow oxidation kinetics and difficulty of complete oxidation.In this study,formate,which has relatively faster oxidation kinetics,was mixed with ethanol to compensate the latter’s sluggish kinetics.Effects of p H,concentration,scan rate,and temperature on the mixed reactants oxidation on Pd were investigated by electrochemical experiments such as potential sweep and potentiostatic methods.Furthermore,the potential of the mixed reactants as fuel was evaluated by single cell experiments.As a result,we demonstrate that mixing formate with ethanol results in enhanced power performance in a single cell system. 展开更多
关键词 ETHANOL FORMATE Mixed reactants Alkaline media PALLADIUM Electro-oxidation
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Development of high quality Fe_3O_4/rGO composited electrode for low energy water treatment
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作者 Ngoc Tuan Trinh Sangho Chung +1 位作者 Jae Kwang Lee Jaeyoung Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2016年第3期354-360,共7页
Electrochemical water treatment is an attractive technology for water desalination and softening due to its low energy consumption. Especially, capacitive Deionization(CDI) is promising as a future technology for wate... Electrochemical water treatment is an attractive technology for water desalination and softening due to its low energy consumption. Especially, capacitive Deionization(CDI) is promising as a future technology for water treatment. Graphene(rGO) has been intensively studied for CDI electrode because of its advantages such as excellent electrical conductivity and high specific surface area. However, its 2D dimensional structure with small specific capacitance, high resistance between layers and hydrophobicity degrades ion adsorption efficiency. In this work, we successfully prepared uniformly dispersed Fe3O4/rGO nanocomposite by simple thermal reactions and applied it as effective electrodes for CDI. Iron oxides play a role in uniting graphene sheets, and specific capacitance and wettability of electrodes are improved significantly;hence CDI performances are enhanced. The hardness removal of Fe3O4/rGO nanocomposite electrodes can reach 4.3 mg/g at applied voltage of 1.5V, which is 3 times higher than that of separate r GO electrodes.Thus this material is a promising candidate for water softening technology. 展开更多
关键词 Electrochemical water treatment Capacitive deionization Water softening GRAPHEME Fe_3O_4/rGO nanocomposite Fe_3O_4 nanoparticle
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Characterization of arsenic-contaminated groundwater and human health risk assessment in Vietnam
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作者 Van Anh Nguyen Sunbaek Bang Kyoung-Woong Kim 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期74-74,共1页
关键词 越南 地下水 水体污染 人体健康
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Boosting the oxygen evolution reaction performance of wrinkled Mn(OH)_(2) via conductive activation with a carbon binder
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作者 Kahyun Ham Jaewon Lee +1 位作者 Kiyoung Lee Jaeyoung Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第8期580-587,I0016,共9页
Electrochemical water splitting is one of the most reliable approaches for environmental-friendly hydrogen production.Because of their stability and abundance,Mn-based materials have been studied as electrocatalysts f... Electrochemical water splitting is one of the most reliable approaches for environmental-friendly hydrogen production.Because of their stability and abundance,Mn-based materials have been studied as electrocatalysts for the oxygen evolution reaction(OER),which is a more sluggish reaction in the water splitting system.To increase the OER activity of Mn,it is imperative to facilitate the structural change of Mn oxide to the active phase with Mn_(3)+species,known as the active site.Here,we present the relationship between the electronic conductivity in the catalyst layer and the formation of the Mn active phase,δ-MnO_(2),from wrinkled Mn(OH)_(2).Mn(OH)_(2) has poor conductivity,and it disrupts the oxidation reaction toward MnOOH orδ-MnO_(2).Adjacent conductive carbon to Mn(OH)_(2) enabled Mn(OH)_(2) to be oxidized toδ-MnO_(2).Furthermore,after repetitive cyclic voltammetry activation,the more conductive environment resulted in a higher density ofδ-MnO_(2) through the irreversible phase transition,and thus it contributes to the improvement of the OER activity. 展开更多
关键词 Hydrogen production Oxygen evolution reaction Anion exchange membrane water electrolysis Anodization Manganese oxide
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