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A facile one-step approach to hierarchically assembled core-shell-like MnO2@MnO2 nanoarchitectures on carbon fibers： An efficient and flexible electrode material to enhance energy storage

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Nano Research 2016年第5期9卷 1507-1522页

作者： Goli Nagaraju Yeong Hwan Ko Sung Min Cha Sang Hyuk im Jae Su Yu Department of Electronics and Radio Engineering Institute for Wearable Convergence Electronics Kyung Hee University 1732 Deogyeong-daero Giheung-gu Yongin-si Gyeonggi-do 446-701 Republic of Korea Functional Crystallization Center (ERC) Department of Chemical Engineering Kyung Hee University 1732 Deogyeong-daeroGiheuncl-qu Yonqin-si Gyeonqqi-do 446-701 Republic of Korea

Hierarchical core-shell-like MnO2 nanostructures （NSs） were used to anchor MnO2 hexagonal nanoplate arrays （HNPAs） on carbon cloth （CC） fibers. The NSs were prepared by a novel one-step electrochemical deposition method. Under an external cathodic voltage of -2.0 V for 30 min, hierarchical core-shell-like MnO2-NS-decorated MnO2 HNPAs （MnO2 NSs@MnO2 HNPAs） were uniformly grown on CC with reliable adhesion. The phase purity and morphological properties of the samples were characterized by various physicochemical techniques. At a constant external cathodic voltage, growth of MnO2 NSs@MnO2 HNPAs on CC was carried for different time periods. When utilized as a flexible, robust, and binder-free electrode for pseudocapacitors, the hierarchical core-shell-like MnO2 NSs@MnO2 HNPAs on CC showed clearly enhanced electrochemical properties in 1 M Na2SO4 electrolyte solution. The results indicate that the MnO2 NSs@MnO2 HNPAs on CC have a maximum specific capacitance of 244.54 F/g at a current density of 0.5 A/g with excellent cycling stability compared to that of bare MnO2 HNPAs on CC （112.1 F/g at 0.5 A/g current density）. We believe that the superior charge storage performance of the pseudocapacitive electrode can be mainly attributed to the hierarchical MnO2 NSs@MnO2 HNPAs building blocks that have a large specific surface area, offering additional electroactive sites for efficient electrochemical reactions. The facile and single-step approach to growth of hierarchical pseudocapacitive materials on textile based electrodes opens up the possibility for the fabrication of high-performance flexible energy storage devices.

关键词： manganese oxide hierarchical structures carbon cloth electrochemical deposition energy storage properties

Web search volume as a surrogate of public interest in biodiversity: a case study of Japanese red list species

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Ecosystem Health and Sustainability 2018年第12期4卷 26-35页

作者： Ji Yoon Kim Akira Noda Ran-Young im Jun Nishihiro Department of Environmental Science Toho UniversityChibaJapan Center for Wildlife Conservation Studies Toho UniversityChibaJapan

Introduction:Citizen science has contributed substantially to the quantity of biodiversity data collections and is used as an essential monitoring scheme for global conservation ***,there remain large gaps in the geographic and taxonomic coverage of data collections,and different levels of interest in participation and uneven distribution of participants can result in biased data collection in citizen science *** issues must be addressed for more efficient use of citizen science-based biodiversity *** compared web search volumes with citizen-collected occurrence data of Japanese Red List ***:Uneven distribution of web search volumes with different taxa was correlated with the amount of data collected by citizen-volunteered ***,the relative web search volumes and amounts of citizen-collected data showed similar spatial patterns at the province ***:Overall,our results indicate that web search volume can indirectly reflect potential citizen participation or interest in particular *** search behavior can help project coordinators estimate potential citizen engagement and refine efficient citizen participation programs for biodiversity conservation.

关键词： Big data citizen science culturomics endangered species internet behavior

Warming hiatus-and evergreen conifers in Altay-Sayan Region,Siberia

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Journal of Mountain Science 2018年第12期15卷 2579-2589页

作者： Viacheslav I.KHARUK Sergei T.im Il'ya A.PETROV Sukachev Institute of Forest Federal Scientific CenterRussian Academy of ScienceSiberian BranchAcademgorodok 50/28Krasnoyarsk660036Russia Siberian Federal University Suobodny str.79Krasnoyarsk 660041Russia Reshetnev Siberian State University of Science and Technology Krasnoyarsky rabochy str.31Krasnoyarsk 660014Russia

"Warming hiatus" occurred in the AltaySayan Mountain Region, Siberia in c. 1997–2014. We analyzed evergreen conifer(EGC) stands area(satellite data) and trees(Siberian pine, Pinus sibirica Du Tour, Siberian fir, Abies sibirica Ledeb.) growth increment(dendrochronology data) response to climate variables before and during the hiatus. During the hiatus, EGC area increased in the highlands(>1000 m)(+30%), whereas at low and middle elevations(lopes mainly. In highlands, EGC area increase mainly correlated with summer air temperature, whereas at low and middle elevations EGC area decrease correlated with drought index SPEI and vapor pressure deficit(VPD). EGC mortality(fir and Siberian pine) in lowland was caused by the synergy of water stress(inciting factor) and barkbeetle attacks(contributing factor). Tree growth increment(GI) dynamics differs with respect to elevation. At high elevation(1700 m) GI permanently increased since warming onset, whereas at the middle(900 m) and low elevations(450 m) GI increased until c. 1983 yr. with followed depression. That GI "breakpoint" occurred about a decade before hiatus onset. In spite of growth depression, during hiatus GI was higher than that in pre-warming period. At high elevation, GI positively responded to elevated June temperatures and negatively to moisture increase(precipitation, root zone moisture content, VPD, and SPEI). At low elevation GI negatively responded to June temperatures and positively to moisture increase. For both, low and high elevation, these patterns persisted throughout the study period(1967–2014). On the contrary, at middle elevations GI dependence on climate variables switch after breakpoint year(1983). Before breakpoint, June air temperature(positive correlation) and moisture(negative correlations) controlled GI. Further temperature increase leads GI depression and switched correlation signs

关键词： Growth increment Warming hiatus Warming impact Conifer decline Tree growth Tree mortality Conifer mortality Water stress

Fatigue crack in large-scale tubular joints for offshore structures

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Science China(Technological Sciences) 2011年第3期54卷 705-714页

作者： Chul-Hee JO Sung-Woo im Won-Chul CHO Kwan-Kyu PARK Department of Naval Architecture and Ocean Engineering Inha University Research Institute of Industrial Science and Technology Department of Civil & Environmental Engineering Chung-Ang University Samsung Heavy Industry Inc.

Tubular members have been used for constructing offshore structures. Large-scale fatigue tests of welded tubular K-joints under the balanced in-plane bending brace were carried out to investigate the fatigue behavior of API 2W Gr.50 steel produced by POSCO. The experimental results were verified by numerical approaches and compared with the IIW, DnV RP-C203 and API RP 2A-WSD design curves. The test results based on the hot spot stress were in agreement with the design curves. The SCF factor for tubular K-joint was also obtained. The numerical parametric study of the K-joint (using the finite element program) was described and its results were compared with experimental results. The stress effects of various parameters including α, β, γ, τ and θ on the stress in the K-joint were investigated. The stress distribution for each parameter was introduced. The study showed that the maximum stress of the joint varied according to the variation of joint parameters.

关键词： tubular K-joint API 2W Gr.50 hot spot stress SCF fatigue through-thickness crack S-N curve numerical parametric study

White organic light-emitting diodes based on electroplex from polyvinyl carbazole and carbazole oligomers blends

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Chinese Physics B 2010年第3期19卷 546-550页

作者：陈飞鹏徐斌赵祖金田文晶吕萍 im Chan State Key Laboratory of Supramolecular Structure and Materials Jilin University Department of Chemistry Zhejiang University Department of Chemistry Konkuk UniversityKorea

White organic light-emitting diodes with a blue emitting material fluorene-centred ethylene-liked carbazole oligomer （Cz6F） doped into polyvinyl carbazole （PVK） as the single light-emitting layer are reported. The optical properties of Cz6F, PVK, and PVK：Cz6F blends are studied. Single and double layer devices are fabri- cated by using PVK： Cz6F blends, and the device with the configuration of indium tin oxide （ITO）/PVK：Cz6F/ tris（8-hydroxyquinolinate）aluminium （Alq3）/LiF/A1 exhibits white light emission with Commission Internationale de l＇Eclairage chromaticity coordinates of （0.30, 0.33） and a brightness of 402 cd/m^2. The investigation reveals that the white light is composed of a blue-green emission originating from the excimer of Cz6F molecules and a red emission from an electroplex from the PVK：Cz6F blend films.

关键词： white organic light-emitting diodes electroluminescence electroplex

Trap and 1/f-noise effects at the surface and core of GaN nanowire gateall-around FET structure

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Nano Research 2019年第4期12卷 809-814页

作者： Mallem Siva Pratap Reddy Ki-Sik im Jung-Hee Lee Raphael Caulmione Sorin Cristoloveanu School of Electronics Engineering Kyungpook National University Daegu 41566 Republic of Korea Advanced Material Research Center Kumoh National Institute of Technology Gumi 39177 Republic of Korea SOITEC Bernin 38190 France Institute of Microelectronics Electromagnetism and Photonics Grenoble Polytechnic Institute Minatec Grenoble 38016 France

Using capacitance,conductance and noise measurements,we investigate the trapping behavior at the surface and in the core of triangular-shaped one-dimensional (1 D) array of GaN nanowire gate-all-around field effect transistor (GAA FET),fabricated via a top-down *** surface traps in such a low dimensional device play a crucial role in determining the device *** estimated surface trap density rapidly decreases with increasing frequency,ranging from 6.07 × 1012 cm-2·eV-1 at 1 kHz to 1.90 × 1011 cm-2·eV-1 at 1 MHz,*** noise results reveal that the power spectral density increases with gate voltage and clearly exhibits 1/f-noise signature in the accumulation region (Vgs > Vth =3.4 V) for all *** the surface depletion region (1.5 V lower frequencies and 1/f2 noise at frequencies higher than ~ 5 *** 1/f2 noise characteristics is attributed to additional generation-recombination (G-R),mostly caused by the electron trapping/detrapping process through deep traps located in the surface depletion region of the *** cutoff frequency for the 1/f2 noise characteristics further shifts to lower frequency of 102-103 Hz when the device operates in deep-subthreshold region (Vgs ime,the electron trapping/detrapping process through deep traps expands into the totally depleted nanowire core and the G-R noise prevails in the entire nanowire channel.

关键词： gate-all-around field effect transistor (FET) nanowire GaN trap 1/f-noise

Influences of diel and tidal cycles on fish assemblage in eelgrass(Zostera marina) bed of southern Korea during autumn

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Acta Oceanologica Sinica 2018年第4期37卷 40-47页

作者： KWAK Seok Nam PARK Joo Myun im Seong Oh JAWAD Laith A. Environ-Ecological Engineering Institute Co. Ltd. Busan 48280 Republic of Korea Department of Biological Sciences Macquarie University Sydney NSW 2109 Australia Department of Marine Bioscience Gangneung-Wonju National University Gangneung 25457 Republic of Korea Korea Marine Environment Management Corporation Seou105718 Republic of Korea Flat Bush Manukau Auckland 2016 New Zealand

Short-term tidal and diel variations of autumn fish assemblage in a Zostera marina bed were investigated using 3 h interval samplings for 24 h in both spring and neap tide using a small beam trawl.A total of 1 346 fishes belonging to 19 species were collected at spring tide,whereas 1 115 fishes belonging to 17 species were at neap *** common fish species were Nuchequula nuchalis,Acanthogobius flavimanus,Takifugu niphobles,Acentrogobius pflaumii,and Pholis nebulosa with the former three species dominating at spring tide,while the latter two species being abundant at neap *** variation in abundance was significant with higher abundance at night than day,but there were no significant differences between spring and neap tides,and between ebb and flood tides（three-way ANOVAs）.Diel variation in the abundance of fishes may be influenced by tidal range and cycle,and day-night differences of food availability and behaviors of fishes ***-metric multidimensional scaling（n MDS） ordination and analysis of similarity（ANOSim） results revealed significant differences in species compositions both between day and night,and between spring and neap *** beds are highly productive marine ecosystem,and thus,our results will contribute to conservation of seagrass ecosystem in the study area.

关键词： tidal and diel variations fish assemblage eelgrass Zostera marina southern Korea

Olfactory Response of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) to Volatiles Emitted by Mungbean Plants

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Agricultural Sciences in China 2011年第4期10卷 560-565页

作者： BAI Shu-xiong WANG Zhen-ying HE Kang-lai im Dae-joon State Key Laboratory of Plant Diseases and Insect Pests Institute of Plant Protection Chinese Academy of Agricultural Sciences Beijing 100193 P.R.China National Crop Experiment Station Rural Development Administration Suwon 441-100 Republic of Korea

Intercropping maize with the prostrate variety of mungbean, Vigna radiata （L.） Wilczek which grows flat along the ground can increase parasitism of the eggs of the Asian corn borer, Ostrinia furnacalis （Guenée）, a crucial insect pest of maize in China, by Trichogramma ostriniae Pang Chen. This study investigated the behavioural responses of T. ostriniae to plant volatiles emitted from whole plants, leaves, and flowers of prostrate and erect varieties of mungbean in a 4-armed olfactometer. Female parasitiods were significantly attracted to the odours from some varieties of prostrate mungbean when the visit duration and the number of visits were considered, but were not attracted to the odours from any erect varieties. The attractive odours were shown to emanate from the leaves, rather than from the flowers of prostrate mungbean plants. These results have implications for the augmentation of Trichogramma parasitoids in bio-control of O. furnacalis and other crop pests.

关键词： Trichogramma ostriniae olfactory response Vigna radiata plant volatile

Predicting the Rainfall-Triggered Landslides in a Forested Mountain Region Using TRIGRS Model

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Journal of Mountain Science 2010年第1期7卷 83-91页

作者： Dongyeob Kim Sangjun im Sang Ho LEE Youngjoo HONG Kyung-Sub CHA Dept. of Forest Sciences Seoul National University Dept. of Forest Sciences Research Institute for Agriculture & life sciences Seoul National University Civil Engineering Team DaeWoo E&C Suwon 440-210 Korea

Landslides are natural disasters which can pose a serious threat to human and property in many areas around the world. The Transient Rainfall Infiltration and Grid-based Regional Slope-stability (TRIGRS) model was used to investigate the rainfall-induced shallow landslides in a forested mountain region, Korea. Various input data for TRIGRS model include time-varying rainfall, topographic characteristics, soil depth, material strength, and hydraulic properties. A series of calculations were conducted in determining the slope stability over the Jangheung region in Korea during the storm occurred on August 6, 1998. The results show that TRIGRS model captured about 64.1% of landslides that were extracted from the IKONOS2 imageries. The model demonstrated how the factor of safety changed with time during a storm considering both the transient and spatial responses of pore water pressure in its slope stability calculation.

关键词： TRIGRS landslides IKONOS2 safetyfactor slope stability Korea