检索结果-南通市图书馆

EXPERIMENTAL AND NUMERICAL INVESTIGATION OF BUBBLE AUGMENTED WATERJET PROPULSION

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2012年第5期24卷 635-647页

作者： choi jin-Keun SINGH Sowmitra HSIAO Chao-Tsung CHAHINE Georges L DYNAFLOW INC. JessupMarylandUSA

This contribution presents experimental and numerical investigations of the concept jet propulsion augmentation using bubble injection. A half-3D （D-shaped cylindrical configuration to enable optimal visualizations） divergent-convergent nozzle was designed, built, and used for extensive experiments under different air injection conditions and thrust measurement schemes. The design, optimization, and analysis were conducted using numerical simulations. The more advanced model was based on a two-way coupling between an Eulerian description of the flow field and a Lagrangian tracking of the injected bubbles using our Surface Averaged Pressure （SAP） model. The numerical results compare very favorably with nozzle experiments and both experiments and simulations validation the thrust augmentation concept. For a properly designed nozzle and air injection system, air injection produces net thrust augmentation, which increases with the rate of bubble injection. Doubling of thrust was measured for a 50% air injection rate. This beneficial effect remains at 50% after account for liquid pump additional work to overcome increased pressure by air injection.

关键词： waterjet propulsion bubble dynamics multi-phase flow

Diverse Functions of VDUP1 in Cell Proliferation,Differentiation,and Diseases

在线全文

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2007年第5期4卷 345-351页

作者： Sang Yong Kim Hyun-Woo Suh jin woong Chung Suk-Ran Yoon Inpyo choi Stem Cell Research Center Korea Research Institute of Bioscience and BiotechnologyYusongTaejon 305-333Republic of Korea

Vitamin D3 up-regulated protein 1 （VDUP1） is a multifunctional protein involved in maintaining cellular homeostasis. VDUP1 is induced by a variety of stresses. Inversely, VDUP1 is often reduced in various tumor tissues and cell lines. Over-expression of VDUP1 inhibits cell proliferation through cell cycle arrest. VDUP1 interacts with thioredoxin （Trx） and negatively regulates the expression and antioxidant function of Trx which is involved in redox regulation. VDUP1/ mice are more susceptible to carcinogenesis than wild-type mice and are defective in establishing immune system induding the development and function of natural killer cells. Furthermore, VDUP1^-/- mice show impaired Kreb cycle-mediated fatty acid utilization. In this review, we have discussed the multifunctional roles of VDUP1 in diverse cellular responses, in particular its relation to proliferation, apoptosis, differentiation, and diseases such as cancer and stress-related diseases.

关键词： VDUP1 thioredoxin proliferation immune cell

Dietary composition of birds in isolated ecosystems:a case study of Black Wood Pigeon in Republic of Korea

在线全文

学校读者我要写书评

暂无评论

Ecosystem Health and Sustainability 2020年第1期6卷 117-126,116页

作者： Soon Kyoo choi Yung Chul Park Sung Wan Park Jae woong Kim Woo Yuel Kim Division of Forest Science Kangwon National UniversityChuncheonRepublic of Korea Department of Biology Kyungpook National UniversityDaeguRepublic of Korea Earth Ecological Environment Research Institute DaejeonRepublic of Korea Division of National Ecosystem Survey Research NIESeocheonRepublic of Korea

We studied the feeding ecology of the Black Wood Pigeon(Columba janthina),a species endemic to the East Asian Pacific Islands,and determined the species’dietary composition and food preferences on Ulleung Island,South Korea,through field *** March 2016 to February 2018,the diversity of food items consumed was low,with the 10 most common plant species(from a total of 33)accounting for over 80%.Food availability varied depending on plant abundance,but this influence was minimized because of factors such as delayed fruit *** were the most favored food items(60-68%)but were replaced by nuts and weed seeds during the spring and winter *** composition and food preferences were related to the abundance of food items based on their phenology,but a steady,high preference for Aphananthe aspera was observed throughout the study *** abundance of Prunus takesimensis in June was correlated with changes in the Black Wood Pigeon *** study is the first to assess the feeding ecology of Black Wood Pigeons using field observations and suggests that the availability of different food items affects population changes on the East Asian Pacific islands.

关键词： Dietary composition feeding preference field observations fruit phenology seasonal variation

Sulfur-doped hard carbon hybrid anodes with dual lithium-ion/metal storage bifunctionality for high-energy-density lithium-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

Carbon Energy 2023年第1期5卷 71-81页

作者： Sungmin Cho Jong Chan Hyun Son Ha Yeonhua choi Honggyu Seong Jaewon choi Hyoung-Joon jin Young Soo Yun Program in Environmental and Polymer Engineering Inha UniversityIncheonSouth Korea KU-KIST Graduate School of Converging Science and Technology Korea UniversitySeoulSouth Korea Departmant of Chemistry and Research Institute of Natural Science Gyeongsang National UniversityJinjuSouth Korea Department of Polymer Science and Engineering Inha UniversityIncheonSouth Korea Division of Energy Engineering Kangwon National UniversityGangwon-doSouth Korea

Bifunctional hybrid anodes(BHAs),which are both a high-performance active host material for lithium-ion storage as well as a guiding agent for homogeneous lithium metal nucleation and growth,exhibit significant potential as anodes for next-generation high-energy-density lithium-ion batteries(LIBs).In this study,sulfur-doped hard carbon nanosphere assemblies(S-HCNAs)were prepared through a hydrothermal treatment of a liquid organic precursor,followed by high-temperature thermal annealing with elemental sulfur for application as BHAs for *** a carbonate-based electrolyte containing fluoroethylene carbonate additive,the S-HCNAs showed high lithium-ion storage capacities in sloping as well as plateau voltage sections,good rate capabilities,and stable *** addition,high average Coulombic efficiencies(CEs)of~96.9%were achieved for dual lithium-ion and lithium metal storage *** the LIB full-cell tests with typical NCM811 cathodes,the S-HCNA-based BHAs containing~400 mA h g^(−1) of excess lithium led to high energy and power densities of~500Wh kg^(−1) and~1695Wkg^(−1),respectively,and a stable cycling performance with~100%CEs was achieved.

关键词： hard carbon hybrid anode lithium-ion batteries lithium metal anode lithium metal batteries sulfur-doped carbon

Long-term outcomes of penetrating keratoplasty in keratoconus: analysis of the factors associated with final visual acuities

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) 2014年第3期7卷 517-521页

作者： jin A choi Min A Lee Man-Soo Kim Department of Ophthalmology St. Vincent's HospitalCollege of Medicine the Catholic University of Korea #93 Jungbudae-ro Paldal-gu Suwon-si Kyunggi-do 442-723Korea Department of Ophthalmology and Visual Science Seoul St.Mary's Hospital College of Medicine Catholic University of Korea #505 Banpo-dong Seocho-ku Seoul 137-701 Korea

AIM:To investigate the long-term results of penetrating keratoplasty(PK)in patients with keratoconus(KC)and to evaluate factors that might influence the final visual ***:We retrospectively reviewed the data of all patients with clinical KC who had undergone PK by a single corneal surgeon in a single center from May 1980to December *** age of the patients,preoperative best-corrected visual acuity(BCVA),corneal thickness,death to preservation time,and preservation to transplantation time were ***,postoperative complications such as graft rejection,development of glaucoma and specular microscopy were checked during the ***:Sixty-nineeyesfrom69patientswerefinally *** follow-up period was 8.64±*** rejection occurred in 4 eyes of 69 cases(5.8%),and the time to graft rejection was 2.1±1.3y.A Kaplan-Meier survival analysis showed that the estimated cumulative probability of graft rejection at 6,13,and 17y after PK were 95.6%,90.0%,and 78.8%,*** we evaluated factors that might influence final BCVA in eyes,no disparity donor-host trephine size(same graft size)as well as higher spherical equivalent,and average Kvalue were associated with higher final BCVA.(P=0.006,0.051,0.092,and 0.021 in eyes with follow-up<8y;P=0.068,0.065,and 0.030 in eyes with follow-up≥8y,respectively).CONCLUSION:The long-term results of PK in patients with KC were favorable with a high percentage of good *** myopic change and low average K-reading,as well as a surgical technique using the same size donor-recipient button may provide better visual outcomes particularly in patients with KC.

关键词： keratoconus penetrating keratoplasty visual outcome

Monolayer Graphitic Carbon Nitride as Metal-Free Catalyst with Enhanced Performance in Photo- and Electro-Catalysis

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-Micro Letters 2022年第3期14卷 308-321页

作者： Huiyan Piao Goeun choi Xiaoyan jin Seong‑Ju Hwang Young Jae Song Sung‑Pyo Cho jin‑Ho Choy Intelligent Nanohybrid Materials Laboratory(INML) Institute of Tissue Regeneration Engineering(ITREN)Dankook UniversityCheonan 31116Republic of Korea College of Science and Technology Dankook UniversityCheonan 31116Republic of Korea Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine Dankook UniversityCheonan 31116Republic of Korea Department of Materials Science and Engineering College of EngineeringYonsei UniversitySeoul 03722Republic of Korea SKKU Advanced Institute of Nanotechnology(SAINT) Sungkyunkwan University(SKKU)Suwon 440‑746Republic of Korea Department of Nano Engineering Sungkyunkwan University(SKKU)Suwon 440‑746Republic of Korea National Center for Inter‑University Research Facilities(NCIRF) Seoul National UniversitySeoul 08826Republic of Korea Graphene Research Center Advanced Institute of Convergence TechnologySuwon 16229Republic of Korea Department of Pre‑Medical Course College of MedicineDankook UniversityCheonan 31116Republic of Korea Tokyo Tech World Research Hub Initiative(WRHI) Institute of Innovative ResearchTokyo Institute of TechnologyYokohama 226‑8503Japan

The exfoliation of bulk graphitic carbon nitride(g-C_(3)N_(4))into monolayer has been intensively studied to induce maximum sur-face area for fundamental studies,but ended in failure to realize chemi-cally and physically well-defined monolayer of g-C_(3)N_(4)mostly due to the difficulty in reducing the layer thickness down to an atomic *** has,therefore,remained as a challenging issue in two-dimensional(2D)chemistry and physics *** this study,an“atomic monolayer of g-C_(3)N_(4)with perfect two-dimensional limit”was successfully prepared by the chemically well-defined two-step *** atomically resolved monolayer of g-C_(3)N_(4)was also confirmed by spectroscopic and micro-scopic *** addition,the experimental Cs-HRTEM image was collected,for the first time,which was in excellent agreement with the theoretically simulated;the evidence of monolayer of g-C_(3)N_(4)in the perfect 2D limit becomes now clear from the HRTEM image of orderly hexagonal symmetry with a cavity formed by encirclement of three adjacent heptazine *** to bulk g-C_(3)N_(4),the present g-C_(3)N_(4)monolayer showed significantly higher photocatalytic gen-eration of H2O2 and H2,and electrocatalytic oxygen reduction *** addition,its photocatalytic efficiency for H2O2 production was found to be the best for any known g-C_(3)N_(4)nanomaterials,underscoring the remarkable advantage of monolayer formation in optimizing the catalyst performance of g-C_(3)N_(4).

关键词： Graphitic carbon nitride Monolayer Atomic image Electro-and photo-catalysis

Marine ciliate community in relation to eutrophication of coastal waters in the Yellow Sea

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and Limnology 2011年第1期29卷 118-127页

作者：徐奎栋 choi Joong Ki 类彦立 YANG Eun jin Institute of Oceanology Chinese Academy of Sciences Department of Oceanography Inha University Korea Polar Research Institute

We assessed the potential of marine ciliate community as an indicator to coastal water quality using water samples collected from four stations in thc Yellow Sea in the summer 2000. The four stations were characterized by different levels of pollution. The ciliate communities consisted primarily of tintinnids and aloricate ciliates that were 〈30 um. A total of 78 species were classified： 55 species at Station 2, 51 species each at Stations l and 4, and 47 species at Station 3. The mean number of species at each site was 29.2±2.0 （Station 1）, 28.5±2.9 （Station 2）, 27.8±1.7 （Station 3）, and 24.5±2.3 （Station 4）. The abundance was highly variable： 19 331±11 187 ind./L at Station 1, 7 960±5 639 ind./L at Station 2, 29 015±12 999 ind./L at Station 3, and 8 190±4 658 ind./L at Station 4. Our results suggest that neither the simple chemical analysis （e.g. chemical oxygen demand, dissolved inorganic nitrogen, and phosphate） nor the eutrophication/pollution index adequately described the water quality at the four stations. The same was true of the number of species and their abundance, both of which had no correlation with the chemical indices. In contrast, Margalef＇s diversity index values （3.12 at Station 2, 2.89 at Station 1, and 2.64 at Stations 3 and 4） generally discriminated the water quality status of the four stations. The difference in water quality among the stations was strongly supported by the pattern of species richness （i.e. the total number of species） of ciliates at each station. Our evaluation was consistent with the results of long-term water quality monitoring at the four stations. With increasing eutrophication, we observed also a compositional and functional shift in the ciliate assemblages from algivorous oligotrich/choreotrich to nonselective-omnivorous gymnostomatids to bacterivorous-detrivorous scuticociliatids. Thus, eiliates may be used to indicate the coastal water quality status of a given site.

关键词： biomonitoring chemical evaluation ciliates community structure eutrophication marine pollution

Assembly of charged aerosols on non-conducting substrates via ion-assisted aerosol lithography （IAAL）

在线全文

学校读者我要写书评

暂无评论

Particuology 2017年第4期15卷 17-23页

作者： Seunghyon Kang Wooik Jung Dae Seong Kim Sei jin Park Mansoo choi School of Mechanical and Aerospace Engineering Seoul National University Seou 108826 Republic of Korea Global Frontier Center for Multiscale Energy Systems Seoul National University Seou108826 Republic of Korea

The development of ion-assisted aerosol lithography （IAAL） has enabled fabrication of complex three- dimensional nanoparticle （NP） structures on conducting substrates. In this work, the applicability of the IAAL technique was investigated on non-conducting substrates. The NP structure growth process on a non-conducting substrate was found to self-terminate and the structures subsequently repel incoming charged NPs and scatter them away. Electric field calculations supported the experimental findings and confirmed that the electric field distortions owing to charge build-up within the structures prevented additional NP deposition thereon. To regulate the charge build-up without compromising the number of NPs available for assembly, a corona discharger and an ion trap were implemented. By varying the number of ions available in the assembly process, an optimum level of ion injection was found that allowed for a prolonged （〉120 rain） assembly of NP structures on non-conducting substrates without the unwanted scattering of NPs.

关键词： Nanoparticle assembly Non-conducting substrate Ion-assisted aerosol lithography Ion trap

Wave-Tide-Surge Coupled Simulation for Typhoon Maemi

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 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