检索结果-南通市图书馆

Report of a Dicephalic Steppes Ratsnake (Elaphe dione) Collected in South Korea

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2013年第3期4卷 182-186页

作者： Il-Hun kim ja-kyeong kim Jonathan J.FONG Daesik PARK Department of Biology Kangwon National University School of Biological Sciences Seoul National University Division of Science Education Kangwon National University

In this report, we describe morphological characteristics of a dicephalic Steppes Ratsnake （Elaphe dione） collected from the wild in 2011 in South Korea. The specimen has two heads and two long necks. Unlike normal individuals, the dicephalic snake has divided ventral scales under the necks of the bifurcated columns. The snout- vent length （SVL） and overall total length of the individual are shorter than those of normal snakes of the same age. Nevertheless, the counts of nine different scale types that are often used for classification are all within the ranges of normal individuals. As far as we know, this is the first detailed morphological description of a dicephalic E. dione in the scientific literature.

关键词： dicephalism morphology Steppes Ratsnake Elaphe dione

Can an Invasive Prey Species Induce Morphological and Behavioral Changes in an Endemic Predator? Evidence from a South Korean Snake(Oocatochus rufodorsatus)

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2014年第4期5卷 245-254页

作者： Jun-Haeng HEO Heon-Joo LEE Il-Hun kim Jonathan J.FONG ja-kyeong kim Sumin JEONG Daesik PARK Department of Biology Kangwon National University Division of Science Education Kangwon National University

Introduction of an invasive prey species into an ecosystem may affect an endemic predator＇s fitness by altering the prey-predator system. Successful adaptation may allow the endemic predator to eat and control the invasive species, while unsuccessful adaptation may result in extinction of the predator. We examine the possible effects of the invasive North American bullfrog （Rana [Lithobates] catesbeiana） on the endemic Red-backed rat snake （Oocatochus rufodorsatus） in South Korea. We do so by comparing the morphology and behavior of adult and hatchling snakes from bullfrog-exposed （Taean） and bullfrog-unexposed （Hongcheon） populations. Among the seven morphological characteristics investigated, relative tail length （tail length/snout-vent length） of both adults and hatchlings from Taean was significantly greater than that of adults and hatchlings from Hongcheon. Also, adult snakes from Taean had a signiifcantly shorter latency of ifrst tongue lfick in response to prey compared to adults from Hongcheon. This difference was not observed in hatchlings. In other snake species, a longer relative tail length and shorter latency of ifrst tongue lfick are known to improve foraging efifciency, and these characters may be adaptations ofO. rufodorsatus to prey on bullfrogs. This study provides preliminary evidence that the presence of an invasive prey species may cause morphological and behavioral changes in an endemic predator.

关键词： invasive prey bullfrog Rana catesbeiana Oocatochus rufodorsatus predator response

Simulation of Gamma-Ray and Neutron Spectrometers for Microsatellite Missions

在线全文

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2018年第8期6卷 105-132页

作者： Masayuki Naito Nobuyuki Hasebe Junya Ishii José A.Matias-Lopes Valery V.Dmitrenko Christian Wohler kyeong ja kim School of Advanced Science and Engineering Waseda UniversityTokyoJapan Research Institute for Science and Engineering Waseda UniversityTokyoJapan Department of Physics University of CoimbraCoimbraPortugal National Research Nuclear University MEPhI MoscowRussia Image Analysis Group Dortmund University of TechnologyDortmundGermany Korea Institute of Gescience and Mineral Resources DaejeonSouth Korea

Microsatellites have recently opened windows of frequent and low cost missions for planetary exploration. The performance of gamma-ray and neutron spectrometers on future microsatellite missions is simulated to assess the possibility of observation of hydrogen and major elements, given their concentration on the observation target. The measured elemental abundance will provide important geological constraints, and some of them may serve as space resources. Four different types of target bodies with various hydrogen concentrations in the range of 0 - 20,000 ppm are assumed as target compositions;Earth’s core, C-type, S-type and Martian meteorites. Gamma-ray and neutron emission rates show unique footprints that are related to the different elemental compositions. The starting point is the solid angle subtended between observation target and spectrometers that allow estimating the gamma-ray and neutron count rates emitted by the celestial bodies. In this work, three types of gamma-ray detectors;high-purity germanium (HPGe), CeBr3 and LaBr3(Ce), a neutron spectrometer combining a lithium glass scintillator with a boron loaded plastic scintillator and a dual mode spectrometer Cs2LiYCl6(Ce) (CLYC) are simulated, focusing on their observation backgrounds as a model case for microsatellite based measurements. The background count level of both gamma-ray (except for the LaBr3 detector) and neutron count rates was negligible under these particular conditions. The gamma-ray detectors were compared by the figure of merit, which was determined by their efficiency and energy resolution. It was found that each detector has unique advantages. The HPGe detector has the highest figure of merit due to its excellent energy resolution, whereas the CLYC detector is low in weight and power consumption due to its dual sensitivity to gamma-ray and neutron. The CeBr3 detector is an intermediate choice. The neutron count rates are calculated separately in three energy ranges, i.e. , thermal

关键词： Gamma-Ray Spectrometer Neutron Spectrometer Microsatellite.High Purity Germanium CeBr3 LaBr3(Ce) CLYC

Geometrical and Geotechnical Characteristics of Landslides in Korea under Various Geological Conditions

维普期刊数据库评论

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 Mountain Science 2015年第5期12卷 1267-1280页

作者： kyeong-Su kim Young-Suk SONG Geologic Environment Division Korea Institute of Geoscience and Mineral Resources

The goal of this study is to determine the geometrical and geotechnical characteristics of landslides under various geological conditions using detailed field surveys, laboratory soil tests and precipitation records. Three study areas are selected to consider different rocks, including gneiss in jangheung, granite in Sangju and sedimentary rocks in Pohang, South Korea. Many landslides have occurred in these three areas during the rainy *** records indicate that landslides occurring in the gneiss area of jangheung and granite area of Sangju may be influenced by the hourly rainfall intensity rather than cumulative ***, landslides occurring in the sedimentary rock area of Pohang may be influenced by hourly rainfall intensity and cumulative rainfall. To investigate the factors that influence these types of landslides, a detailed landslide survey was performed and a series of laboratory soil tests were *** to the detailed field survey, most landslides occurred on the flanks of mountain slopes, and the slope inclination where they occurred mostly ranged from 26 to 30 degrees, regardless of the geological conditions. The landslide in the gneiss area of jangheung is larger than the landslides in the granite area of Sangju and sedimentary rock area of ***, the landslide in the sedimentary rock area is shorter and shallower than the landslides in the gneiss and granite areas. Thus, the shape and size of the landslide are clearly related to the geological conditions. According to the integrated soil property and landslide occurrence analyses results, the average dry unit weight of the soils from the landslide sites is smaller than that of the soils obtained from the nonlandslide site. The average coefficient of permeability of soils obtained from the landslide sites is greater than that of soils obtained from the non-landslide sites with the same geology. These results indicate that the soils from the landslide site

关键词： Landslides Geological condition Geometrical characteristics Precipitation Soilproperties South Korea

Standard Embeddings of Smooth Schubert Varieties in Rational Homogeneous Manifolds of Picard Number 1

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2018年第3期34卷 466-487页

作者： Shin-Young kim kyeong-Dong PARK Department of Mathematics and Statistics Masaryk University Brno Czech Center for Geometry and Physics Institute for Basic Science ( IBS) Pohang Korea

Smooth Schubert varieties in rational homogeneous manifolds of Picard number 1 are horospherical varieties. We characterize standard embeddings of smooth Schubert varieties in rational homogeneous manifolds of Picard number 1 by means of varieties of minimal rational tangents. In particular, we mainly consider nonhomogeneous smooth Schubert varieties in symplectic Grassmannians and in the 20-dimensional F_4- homogeneous manifold associated to a short simple root.

关键词： Smooth Schubert varieties rational homogeneous manifolds variety of minimal rational tangents standard embeddings Cartan-Fubini extension

Development of polyimide films reinforced with boron nitride and boron nitride nanosheets for transparent flexible device applications

在线全文

学校读者我要写书评

暂无评论

Nano Research 2018年第5期11卷 2366-2378页

作者： You Jin Min kyeong-Hee Kang Dae-Eun kim Department of Mechanical Engineering Yonsei University 50 Yonsei-ro Seodaemun-gu Seoul 03722 Republic of Korea

The benefits of reinforcing polyimide （PI） films with boron nitride （BN） particles and boron nitride nanosheets （BNNSs） were assessed with the aim of enhancing their thermal, optical, and mechanical properties for flexible device applications. BNNSs were prepared from BN particles using a liquid-phase exfoliation method assisted by an ultrasonic probe-type sonicator and centrifugator. PI-based composite films blended with BNNSs and BN particles were fabricated at various concentrations via mechanical stirring and spin coating. The transparency of the PI/BNNS composite films remained almost the same as that of pure PI films up to 3 wt.% whereas the transparency of the PI/BN composite films decreased with increasing concentration of the BN fillers at 550 nm. The thermal stability improved significantly with increasing concentrations of both BN and BNNS relative to that of pure PI films. The temperature for 5% weight loss of the PI/BNNS composite film was higher than that of the PI/BN composite film at the same filler concentration. The composite films with 2 wt.% BN or BNNS showed the lowest wear rate, and the PI/BNNS composite films showed more stable frictional behavior compared to the PI/BN composite films. In addition, bending tests showed that the PI/BNNS composite films exhibited excellent flexibility compared to the PI/BN composite films. Overall, the results indicate that the BNNS can be effectively used as a filler that can enhance the thermal and mechanical properties of polymer materials for flexible device applications.

关键词： polyimide (PI) boron nitride (BN) transparency thermal properties flexibility tribology

Interface engineering of an electrospun nanofiber-based composite cathode for intermediate-temperature solid oxide fuel cells

维普期刊数据库评论

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 Extreme Manufacturing 2023年第1期5卷 345-353页

作者： Seo Ju kim Deokyoon Woo Donguk kim Tae kyeong Lee jaeyeob Lee Wonyoung Lee School of Mechanical Engineering Sungkyunkwan UniversitySuwonKyunggi-do 16419Republic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon 16419Republic of Korea

Sluggish oxygen reduction reaction(ORR)kinetics are a major obstacle to developing intermediate-temperature solid-oxide fuel cells(IT-SOFCs).In particular,engineering the anion defect concentration at an interface between the cathode and electrolyte is important for facilitating ORR kinetics and hence improving the electrochemical *** developed the yttria-stabilized zirconia(YSZ)nanofiber(NF)-based composite cathode,where the oxygen vacancy concentration is controlled by varying the dopant cation(Y2O3)ratio in the YSZ *** composite cathode with the optimized oxygen vacancy concentration exhibits maximum power densities of 2.66 and 1.51 W cm^(−2)at 700 and 600℃,respectively,with excellent thermal stability at 700℃ over 500 h under 1.0 A cm^(−2).Electrochemical impedance spectroscopy and distribution of relaxation time analysis revealed that the high oxygen vacancy concentration in the NF-based scaffold facilitates the charge transfer and incorporation reaction occurred at the interfaces between the cathode and *** results demonstrate the high feasibility and potential of interface engineering for achieving IT-SOFCs with higher performance and stability.

关键词： solid oxide fuel cells nanofiber infiltration oxygen reduction reactions oxygen vacancy

Wave-Tide-Surge Coupled Simulation for Typhoon Maemi

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2013年第2期27卷 141-158页

作者： Byung Ho Choi Byung Il Min kyeong Ok kim Jin Hee Yuk Department of Civil and Environmental Engineering Sungkyunkwan University Marine Environments & Conservation Research Division Korea Institute of Ocean Science & Technology Supercomputing Center Korea Institute of Science and Technology Information

The main task of this study focuses on studying the effect of wave-current interaction on currents, storm surge and wind wave as well as effects of current induced wave refraction and current on waves by using numerical models which consider the bottom boundary layer and sea surface roughness parameter for shallow and smooth bed area around Korean Peninsula. The coupled system （unstructured-mesh SWAN wave and ADCIRC） run on the same unstructured mesh. This identical and homogeneous mesh allows the physics of wave-circulation interactions to be correctly resolved in both models. The unstructured mesh can be applied to a large domain allowing all energy from deep to shallow waters to be seamlessly followed. There is no nesting or overlapping of structured wave meshes, and no interpolation is required. In response to typhoon Maemi （2003）, all model components were validated independently, and shown to provide a faithful representation of the system＇s response to this storm. The waves and storm surge were allowed to develop on the continental shelf and interact with the complex nearshore environment. The resulting modeling system can be used extensively for prediction of the typhoon surge. The result show that it is important to incorporate the wave-current interaction effect into coastal area in the wave-tide-surge coupled model. At the same time, it should consider effects of depth-induced wave breaking, wind field, currents and sea surface elevation in prediction of waves. Specially, we found that：（1） wave radiation stress enhanced the current and surge elevation otherwise wave enhanced nonlinear bottom boundary layer decreased that, （2） wind wave was significantly controlled by sea surface roughness thus we cautiously took the experimental expression. The resulting modeling system can be used for hindcasting （prediction） the wave-tide-surge coupled environments at complex coastline, shallow water and fine sediment area like areas around Korean Peninsula.

关键词： typhoon Maemi finite element model tide-surge-wave coupling

3D engineered tissue models for studying human-specific infectious viral diseases

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2023年第3期21卷 576-594页

作者： kyeong Seob Hwang Eun U Seo Nakwon Choi Jongbaeg kim Hong Nam kim Brain Science Institute Korea Institute of Science and Technology(KIST)Seoul02792Republic of Korea School of Mechanical Engineering Yonsei UniversitySeoul03722Republic of Korea Yonsei-KIST Convergence Research Institute Yonsei UniversitySeoul03722Republic of Korea Division of Bio-Medical Science&Technology KIST SchoolKorea University of Science and Technology(UST)Seoul02792Republic of Korea KU-KIST Graduate School of Converging Science and Technology Korea UniversitySeoul02841Republic of Korea

Viral infections cause damage to various organ systems by inducing organ-specific symptoms or systemic multi-organ *** on the infection route and virus type,infectious diseases are classified as respiratory,nervous,immune,digestive,or skin *** these infectious diseases can widely spread in the com-munity and their catastrophic effects are severe,identification of their causative agent and mechanisms un-derlying their pathogenesis is an urgent *** infection-associated mechanisms have been studied in two-dimensional(2D)cell culture models and animal models,they have shown limitations in organ-specific or human-associated pathogenesis,and the development of a human-organ-mimetic system is ***,three-dimensional(3D)engineered tissue models,which can present human organ-like physiology in terms of the 3D structure,utilization of human-originated cells,recapitulation of physiological stimuli,and tight cell–cell interactions,were ***,recent studies have shown that these models can recapitulate infection-associated *** this review,we summarized the recent advances in 3D engineered tissue models that mimic organ-specific viral ***,we briefly described the limitations of the current 2D and animal models in recapitulating human-specific viral infection ***,we provided an overview of recently reported viral infection models,focusing particularly on organ-specific infection ***,a future perspective that must be pursued to reconstitute more human-specific infectious diseases is presented.

关键词： 3D engineered tissue model Infectious viral disease Infection route Pathology In vivo-mimicking