检索结果-南通市图书馆

Anticipating the lifespan: Predicting the durability of an anode-supported solid oxide fuel cell short stack over 50,000 h

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2024年第3期34卷 606-613页

作者： Muhammad Zubair Khan Amjad Hussain seung-Bok Lee Tak-Hyoung lim Rak-Hyun Song Department of Materials Science & Engineering Pak-Austria Fachhochschule: Institute of Applied Sciences and Technology Hydrogen Energy Research Division Korea Institute of Energy Research Department of Advanced Energy and System Engineering Korea University of Science and Technology (UST)

In the present study, the operational lifetime of a solid oxide fuel(SOFC) short stack is predicted by investigating the performance degradation of both the short stack and its cells throughout 1000 h at 800°C. The short stack and integral cell voltages are continuously measured during the long-term test, with electrochemical impedance spectroscopy(EIS) conducted every 200 h. The short stack voltage decreased rapidly for the initial 200–300 h and afterwards, it decreased at a slow rate due to the increase in the Ohmic and polarization resistances in the same manner. Scanning electron microscopy results show that there is no delamination or cracking among constituent layers of the short-stack cells. The single degradation effects of the Ni coarsening in the anode, cation migration and surface segregation in cathode and oxide scale growth in metallic interconnect mesh are successfully integrated into a comprehensive lifetime prediction model. The experimentally measured voltage degradation data of the short stack fits well with the developed mathematical model and allows the successful prediction of the lifetime up to 50,000 h.

关键词： SOFC Stack Degradation Impedance Lifetime

Distribution of dinoflagellate cysts in Yellow Sea sediments

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2013年第9期32卷 91-98页

作者： SHIN Hyeon Ho lim Dhongil PARK Soung-Yun HEO seung KIM So-Young Library of Marine Samples Korea Institute of Ocean Science and Technology West Sea Fisheries Research Institute National Fisheries Research&Development Institute Division of Polar Climate Research Korea Polar Research Institute

To investigate the distribution, abundance, and species composition of dinoflagellate cysts in the Yellow Sea, surface sediment samples were collected at 37 sites, including the Korean dump site. Twenty-one di- noflagellate cyst taxa were identified, with the assemblages dominated mainly by Spiniferites bulloideus, Operculodinium centrocarpum, and cyst of Alexandrium catenella/tarnarense type. A high frequency of O. centrocarpum in the Yellow Sea was observed for the first time, and it is likely that this can be attributed to the dynamics of the Yellow Sea Cold Water Mass and the Changjiang （Yangtze） River runoff. Total cyst concentrations ranged from 23 to 48 442 cysts/g dry weight, and high cyst concentrations were recorded adjacent to the dumping site. This result suggests that anthropogenic activities such as ocean dumping s- timulate the growth of dinoflagellates in the Yellow Sea, which in turn leads to high levels of dinoflagellate cyst production.

关键词： Yellow Sea dumping site dinoflagellate cyst Alexandrium catenella/tamarense type Operculo- dinium centrocarpum

Electrically driven, phosphor-free, white light-emitting diodes using gallium nitride-based double concentric truncated pyramid structures

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2016年第1期5卷 665-670页

作者： seung-Hyuk lim Young-Ho Ko Christophe Rodriguez Su-Hyun Gong Yong-Hoon Cho Department of Physics and KI for the NanoCentury Korea Advanced Institute of Science and Technology291 Daehak-roYuseong-guDaejeon 34141Korea Electronics and Telecommunications Research Institute(ETRI) 218 Gajeong-roYuseong-guDaejeon 34129Korea The Laboratoire Nanotechnologies Nanosystémes(LN2)-CNRS UMI-3463 Institut Interdisciplinaire d’Innovation Technologique(3IT)Universitéde Sherbrooke3000 boulevard UniversitéJ1K 0A5QCCanada

White light-emitting diodes(LEDs)are becoming an alternative general light source,with huge energy savings compared to conventional ***,white LEDs using phosphor(s)suffer from unavoidable Stokes energy converting losses,higher manufacturing cost,and reduced thermal ***,we demonstrate electrically driven,phosphor-free,white LEDs based on three-dimensional gallium nitride structures with double concentric truncated hexagonal *** electroluminescence spectra are stable with varying *** origin of the emission wavelength is studied by cathodoluminescence and high-angle annular dark field scanning transmission electron microscopy *** variation of the carrier injection efficiency is also investigated by a comparative analysis between spatially resolved photoluminescence and electroluminescence.

关键词： indium gallium nitride light-emitting diodes phosphor-free three-dimensional structures white color

Broadband omnidirectional light detection in flexible and hierarchical ZnO/Si heterojunction photodiodes

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 2017年第1期10卷 22-36页

作者： Seongdong lim Doo-seung Um Minjeong Ha Qianpeng Zhang Youngsu Lee Yuanjing Lin Zhiyong Fan Hyunhyub Ko School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan Metropolitan City 44919 Republic of Korea Department of Electronic and Computer Engineering Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong China

The development of flexible photodetectors has received great attention for future optoelectronic applications including flexible image sensors, biomedical imaging, and smart, wearable systems. Previously omnidirectional photodetectors were only achievable by integration of a hemispherical microlens assembly on multiple photodetectors. Herein, a hierarchical photodiode design of ZnO nanowires （NWs） on honeycomb-structured Si （H-Si） membranes is demonstrated to exhibit excellent omnidirectional light-absorption ability and thus maintain high photocurrents over broad spectral ranges （365 to 1,100 nm） for wide incident angles （0° to 70°）, which enabled broadband omnidirectional light detection in flexible photodetectors. Furthermore, the stress-relieving honeycomb pattern within the photodiode micromembranes provided photodetectors with excellent mechanical flexibility （10% decrease in photocurrent at a bending radius of 3 mm） and durability （minimal change in photocurrent over 10,000 bending cycles）. When employed in semiconductor thin films, the hierarchical NW/honeycomb heterostructure design acts as an efficient platform for various optoelectronic devices requiring mechanical flexibility and broadband omnidirectional light detection.

关键词： flexible photodetector photodiode omnidirectional hierarchicalzinc oxide nanowire

High-performance solid-solution potassium-ion intercalation mechanism of multilayered turbostratic graphene nanosheets

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 2022年第4期31卷 814-823页

作者： Jiae Um seung Uk Yoon Hoseong Kim Beom Sik Youn Hyoung-Joon Jin Hyung-Kyu lim Young Soo Yun Program in Environmental and Polymer Engineering Inha Universityncheon 22212 South Korea Department of Polymer Science and Engineering Inha UniversityIncheon 22212South Korea Division of Chemical Engineering and Bioengineering Kangwon National University Chuncheon Gangwon-do 24341 South Korea KU-KIST Graduate School of Converging Science and Technologyea University 145 Anam-roSeongbuk-guSoul02841 South Korea Department of Integrative Energy Engineering 145 Anam-roSongbuk-guKorea UniversitySeoul 02841 South Korea

The solid-solution reaction between an alkali cation and an active host material is known as a singlephase redox mechanism,and it is typically accompanied by a continuous voltage *** is distinct from the typical alkali cation intercalation reaction at an equivalent site of the active host material,which exhibits a voltage ***,we report an unusual solid-solution potassium-ion intercalation mechanism with a low-voltage plateau capacity on multilayered turbostratic graphene nanosheets(T-GNSs).Despite the disordered graphitic structure with a broad range of d-spacings(3.65–4.18À),the T-GNSs showed a reversible plateau capacity of~200 m A h g^(-1),which is higher than that of a well-ordered graphite nanoplate(~120 m A h g^(-1)).In addition,a sloping capacity of~220 m A h g^(-1)was delivered with the plateau capacity,and higher rate capabilities,better reversibility,and a more stable cycling performance were confirmed on the turbostratic ***-principles calculations suggest that the multitudinous lattice domains of the T-GNSs contain diverse intercalation sites with strong binding energies,which could be the origin of the high-performance solid-solution potassium-ion intercalation behavior when the turbostratic graphene stacks have a d-spacing smaller than that of equilibrium potassium–graphite intercalation compounds(5.35À).

关键词： Turbostratic graphite Graphene nanosheet Defective carbon Anode Potassium-ion batteries

Effects of solid-state fermentation using R. oligosporus on the phytochemical composition of wild-simulated ginseng leaf and its biological properties

在线全文

学校读者我要写书评

暂无评论

Food Bioscience 2023年第2期52卷 532-540页

作者： Juho lim Hayeong Kim Sung Bae Park Kunal Pal seung Wook Kim Doman Kim Graduate School of International Agricultural Technology Seoul National UniversityGangwon-do25354Republic of Korea Institute of Food Industrialization Institutes of Green Bioscience and TechnologySeoul National UniversityGangwon-do25354Republic of Korea Biseondong Wild Ginseng Company Hongcheon-gunGangwon-do25162Republic of Korea Department of Biotechnology and Medical Engineering National Institute of TechnologyRourkela769008India Ottogi Corporation Anyang-siGyeonggi-do14060Republic of Korea Fervere Campus Corporation Gangwon-do25354Republic of Korea

Wild-simulated ginseng(WSG)grown in the mountains without specific facilities is widely used as functional foods in Asian countries due to its bioactive compounds,such as ***,long-time cultivation,lower survival rate,and small size of WSG limit its use in the food *** this study,WSG leaves,which can be harvested annually,were fermented using *** for 0-10 *** phytochemical compounds of fermented WSG leaves,including squalene,phenols,saponins,and most ginsenosides(except for Rb1),were increased.L-carnitine was newly synthesized in WSG leaves,with a content of 165.1μg/g measured after 10 days of ***,the minor ginsenosides Rg2,Rg3,Rh1,F1,F2,and CK increased by 1.32-,1.58-,1.42-,1.91-,1.49-,and 4.43-fold compared to non-fermented WSG *** highest antioxidant activities,as measured by FRAP and ORAC assays of WSG leaves,were obtained after 3 days of ***,the suppression of NO release in LPS-stimulated RAW264.7 cells and lipid accumulation in mouse 3T3-L1 cells of fermented WSG leaves was greater than in WSG *** these results,fermented WSG leaves have potential applications as functional materials in the food industry.

关键词： Wild-simulated ginseng leaf L-carnitine Solid-state fermentation R.oligosporus Ginsenosides Anti-inflammation Anti-lipid accumulation

Does the discrepancy in histologic differentiation between a forceps biopsy and an endoscopic specimen necessitate additional surgery in early gastric cancer?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2017年第8期9卷 319-326页

作者： Jae seung Soh Hyun lim Ho Suk Kang Jong Hyeok Kim Kab Choong Kim Department of Internal Medicine University of Hallym College of Medicine Hallym University Sacred Heart Hospital Department of Surgery University of Hallym College of Medicine Hallym University Sacred Heart Hospital

To investigate the clinicopathological variables in early gastric cancer (EGC) patients in relation to differentiation discrepancy. METHODSThe data of 265 specimens from 240 patients with EGC, who had undergone radical operation at Hallym University Sacred Heart Hospital from 2010 to 2015, were retrospectively analyzed. We evaluated clinical, endoscopic, and histopathological data according to histological discrepancy. RESULTSClinically significant discrepancy rate showed the difference in differentiated type (well and moderately differentiated) and undifferentiated type (poorly differentiated and signet ring cell) between endoscopic biopsies and postoperative specimens was 9.4% (25/265). There were no differences in tumor location, size, gross pattern, and number of biopsies. Specimens having histological discrepancy showed more submucosal invasion (72.0% vs 49.6%, P = 0.033) and lymph node involvement (24.0% vs 7.9%, P = 0.009) than specimens having non-discrepancy. The rate of a positive epidermal growth factor receptor status was higher in specimens having discrepancy than in specimens having non-discrepancy (81.0% vs 55.4%, P = 0.035). CONCLUSIONThe discordance of histologic differentiation is associated with higher submucosal invasion and lymph node metastases in EGC. Patients have histological discrepancy may require additional surgical treatments.

关键词： Early gastric cancer Histological discrepancy Differentiation Clinicopathological factor Endoscopic treatment Surgical treatment

Optic perineuritis as an initial presentation of ocular toxoplasmosis:a case report

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 Ophthalmology(English edition) 2022年第12期15卷 2043-2046页

作者： seung Ah Chung Chungwoon Kim Jong Yoon lim Yoo-Ri Chung Department of Ophthalmology Ajou University School of MedicineSuwon 16499Republic of Korea The Bright Eye Center Gwangmyeong 14235Republic of Korea

Dear Editor,Ocular toxoplasmosis,caused by Toxoplasma gondii infection,is one of the most common causes of posterior uveitis worldwide[1].It typically manifests as white focal retinitis with overlying vitreous inflammation that results in a chorioretinal scar and associated scotoma[2].However,the diagnosis of ocular toxoplasmosis can be challenging when it presents as an isolated papillitis without other typical signs of retinochoroiditis or vitritis[2].Although optic nerve involvement in ocular toxoplasmosis was present in 5.3%of cases,isolated papillitis was extremely rare(3 eyes out of 926 patients)and was only considered a presumed diagnosis in such cases given the presence of old toxoplasmic retinochoroiditis lesions[3].Few reports have described optic nerve involvement preceding toxoplasmic retinochoroiditis,while perineuritis,an uncommon form of orbital inflammatory disease involving the optic nerve sheath,has not been reported at all[4-5].Herein,we describe a case of ocular toxoplasmosis that initially presented with optic perineuritis followed by typical retinochoroidal *** our knowledge,this is the first case report of ocular toxoplasmosis with perineuritis in an immunocompetent individual.

关键词： ocular diagnosis neuritis

Evaluation of defects in aluminum piston castings by using ultrasonics and computer tomography

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2012年第3期9卷 275-278页

作者： In-Sung Cho Jeong-Ho Hwang Jin-Seok Yang seung-Mok Yoo Chae-Ho lim Korea Institute of Industrial Technology

Pistons used in automobile engines are made of aluminum alloy; and endurance of high pressure and high temperature is required. Recently, high strength pistons are needed to cope with the increase of pressure and temperature in the engine cylinder. A high strength piston is possible when the piston casting has little or no casting defects, such as micro-pores and cracks. Generally the defects can be evaluated by non-destructive testing (NDT), and the most efficient ways for evaluation are using ultrasonics and computer tomography. In the present study, two NDT methods were compared and evaluated to investigate the defects in the aluminum piston castings. Artificial defects were machined by using very small drill bits with diameters 1, 0.5, 0.3, 0.2 and 0.1 mm. The defects were investigated by using an ultrasonic tester and a computer tomography system. Defects smaller than 0.3 mm may not be found by using the ultrasonic test, but the defects may be found by using the computer tomography system. The investigation conditions for detecting small defects and the scanning time for in-line defect analysis are discussed in the present study.

关键词： piston ultrasonic test computer tomography aluminum defect