检索结果-南通市图书馆

Formation and Characterization of Plasma Sprayed Photocatalytic TiO2- ZnO Nano- Compounded Coatings

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2004年第z2期22卷 162-166页

作者： Lee Soo Wohn Aum Ho Sung Hur Bo Young Chen Huang Division of Materials and Chemical engineering Sun Moon UniversityAsanChungnam 336708Korea Division of Mechanical and Control EngineeringSun Moon UniversityAsanChungnam 336708Korea Division of Materials EngineeringGyeong Sang National UniversityChinju 660701Korea Division of Materials and Chemical EngineeringSun Moon UniversityAsanChungnam 336708Korea

Two kinds of TiO2-ZnO nano-compounded powders aggregated by spray-drying process and evaporation method were used to deposit photocatalytic coatings by atmospheric plasma spraying technique. The phase compositions, morphologies of the agglomerated TiO2-ZnO powders and the as-sprayed coating were characterized using X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) respectively. Furthermore, roughness measurements were carried out on their surfaces of the plasma sprayed TiO2-ZnO nano-comPounded coatings. Compared with the TiO2ZnO nano-compounded coating deposited from the spray-dried powder, it was found that the TiO2-ZnO nano-compounded coating deposited from the evaporated powder possesses higher anatase phase. It is ascribed to the existing of partially melted or non-melted microstructure in the TiO2-ZnO coating deposited from the evaporated powder. The partially-meltedor non-melted microstructure was retained from the starting agglomerated powder. This microstructure is beneficial to improve the photocatalytic properties of plasma sprayed TiO2-ZnO nano-compounded coatings.

关键词： plasma spraying spray-drying evaporation characterization TiO2-ZnO rare earths

Up-conversion luminescence from Nd^(3+) ions doped in NaBi(WO_4)_2 single crystal

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 Rare Earths 2009年第6期27卷 905-910页

作者：魏东磊黄彦林施亮乔学斌徐孝镇 College of Chemistry Chemical Engineering and Materials ScienceSoochow University Department of Physics Pukyong National University

The luminescence of Nd3+-doped in NaBi(WO4)2 single crystal was investigated from 10 K to room *** excitation source was a pulsed dye laser in resonance into the(4G5/2+2G(1)7/2) levels of Nd3+ *** blue emission bands in the up-conversion luminescence spectra corresponded to transitions from 2P1/2 to 4I9/*** violet bands corresponding to transitions of 4D3/2→(4I9/2,4I11/2,4I13/2) were also *** comparison,the luminescence spectra and decay curves excited by the pulsed 355 nm l...

关键词： optical materials NaBi(WO4)2 neodymium up-conversion luminescence rare earths

Goal-Based Automated Code Generation in Self-Adaptive System

在线全文

学校读者我要写书评

暂无评论

Journal of Computer science & Technology 2010年第6期25卷 1118-1129页

作者： Joonhoon Lee Jeongmin Park Giljong Yoo Eunseok Lee Department of Electrical and Computer engineering Sungkyunkwan University Department of Software engineering Dongyang Mirae University

System administrator deals with many problems,as computing environment becomes increasingly *** with an ability to recognize system states and adapt to resolve these problems offer a *** experience and knowledge are required to build a self-adaptive ***-adaptive systems have inherent *** paper proposes a technique that automatically generates the code for the self-adaptive *** the system is easier to ***-adaptive systems of previous research required high system resource *** operation could be invoked by external factors such as *** propose an improved self-adaptive system approach and apply it to video conference system and robot *** compared the lines of code,the number of classes created by the *** have confirmed this enhanced approach to be effective in reducing these development metrics.

关键词： self-adaptive self-healing goal graph activation switch error detection

Magnetic Properties and Magnetoresistance of CdMnS：Au Based Structures Prepared by Co-evaporation

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第7期27卷 282-284页

作者：何俊黎明金大训李载春李东京付德君姜泰远 Department of Physics and Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education Wuhan University Wuhan 430072 Quantum-Functional Semiconductor Research Center (QSRC) Dongguk University 3-26 Seoul 100-715 Korea

Polycrystalline CdMnS and CdMnS：Au films with hexagonal structure on Si（111） substrates are prepared by co-evaporation, and exhibit ferroelectric and ferromagnetic properties, respectively. Under optimized growth conditions, CdMnS：Au samples with an average crystallite size of 90nm and Mn concentration of 5.0at.% are obtained, and an all-semiconductor spin valve device of Co/Au/CdMnS：Au/CdMnS/Pt is fabricated. Electrical measurement of the device reveals the clear dependence of resistance on applied magnetic field, with a relative magnetoresistance of 0.06% and a switching field of 100 Oe at 77K.

关键词： METALLIC films -- Magnetic properties MAGNETORESISTANCE CADMIUM compounds EVAPORATION (Chemistry) MOLECULAR structure SUBSTRATES (Materials science) POLYCRYSTALS FERROMAGNETISM

CREEP BEHAVIOR OF Zr-1.5Nb-0.4Sn-0.1Fe-0.1Cu ALLOY

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

Acta Mechanica Solida Sinica 2008年第4期21卷 308-311页

作者： Ji Young Kim Kwang Su Na Yong Duck Kim Ji Hui Kim Kwon Yeong Lee Ki Nam Kim Seon Jin Kim Division of Advanced Materials science and engineering Hanyang University133-791Korea Technical Research Center Sheet Products Design TeamHyundai Steel CompanyKodae-RiSongak-MyeonDangjin-GunChungnam167-32Korea

Creep behavior of the Zr-1.5Nb-0.4Sn-0.1Fe-0.1Cu alloy sheet is investigated from 300℃ to 400℃ in the stress range from 50 MPa to 180 MPa along the rolling direction. The measured strain rates range from 8.8 × 10^-10 s^-1 to 4.7 × 10^-7 s^-1. The activation energies are estimated to assess the creep deformation mechanisms in this alloy. The strain rate is slightly different at low stress, while it shows a distinct difference at high stresses. Stress exponents of this alloy increase with increasing applied stress at all testing temperatures. It is concluded that the creep deformation of the Zr-1.5Nb-0.4Sn-0.1Fe-0. 1 Cu alloy is controlled by the diffusion creep at low stress region and by the climbing of dislocations at high stress region.

关键词： creep zirconium alloy nuclear cladding

Influence of Aging and 2-hydroxyethyl-methacrylate Content on the Color Stability of Experimental 2-hydroxyethyl-methacrylate-added Dental Glass Ionomers

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2010年第4期26卷 379-384页

作者： Bin Yu Guangfeng Zhao Honam Lim Jinik Lira Yongkeun Lee Department of Dental Materials and Center for Dental Materials School of Dentistry Kyung Hee University Seoul Korea Denforus co. Seaul Korea

Color stability of dental resin modified glass ionomer （RMGI） has been a challenge to dentistry; therefore, systematic changes in 2-hydroxyethyl methacrylate （HEMA） content were performed experimentally to find an idea to enhance the color stability. Changes in color （△E＊ab） and color coordinates （△L＊, △a＊ and △b＊） of experimental 10-50 wt pct HEMA-added dental glass ionomers （HAGIs） and corresponding RMGIs were determined after 5000 cycles of thermocycling. Color changes of HAGIs were not influenced by the HEMA content while △L＊, △a＊ and △b＊ values were influenced by the HEMA content. Color stability of 30% or 40% HEMA-added HAGIs was not different from those of the commercial RMGIs. Since the influence of HEMA itself on the color stability of HAGIs was limited, compositional modification to increase the color stability of these materials should be developed.

关键词： Glass ionomer 2-hydroxyethyl methacrylate (HEMA) Color coordinate Thermocycling

Biogeochemical cyclic activity of bacterial arsB in arsenic-contaminated mines

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2008年第11期20卷 1348-1355页

作者： CHANG Jin-Soo KIM Kyoung-Woong Department of Environment science and engineering Gwangju Institute of Science and Technology (GIST)261 Cheomdan-gwagiroBuk-guGwangjuRepublic of Korea.

Biogeochemical cyclic activity of the ars (arsenic resistance system) operon is arsB influx/effux encoded by the ecological of Pseudomonas *** 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 *** is the first report in which multiple arsB-binding mechanisms have been used on indigenous *** ArsB (strains OS-5; ABB83931; OS-19; ABB04282 and RW-28; ABB88574...

关键词： arsenic resistance bacteria arsB influx/efflux pump arsenic resistance system (ars) biogeochemical

Promoter hypermethylation and loss of CD133 gene expression in colorectal cancers

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第25期16卷 3153-3160页

作者： You-Kyung Jeon Sung-Hee Kim Seung-Ho Choi Kyung-Hee Kim Byong-Chul Yoo Ja-Lok Ku Jae-Gahb Park Laboratory of Cell Biology Cancer Research Institute Seoul National University College of Medicine Seoul 110-799 South Korea Colorectal Cancer Branch Research Institute National Cancer Center Goyang 411-764 Gyeonggi South Korea

AIM: To understand CD133 promoter hypermethyl-ation and expression in 32 colorectal cancer cell lines. METHODS: Nucleic acid was isolated from 32 colorectal cancer cell lines and CD133 expression levels were measured by reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR. Promoter methylation status of the CD133 gene was analyzed with a methylation-specific PCR after sodium-bisulfi te modification and by clonal sequencing analysis. The correlation between expression and promoter methylation of CD133 gene was confirmed with treatment of 5-aza-2’-deoxycytidine. RESULTS: We measured CD133 expression levels in 32 colorectal cancer cell lines. RT-PCR analysis showed undetectable or low levels of CD133 expression in 34.4%of cell lines. To verify the relation between CD133 expression and methylation status of the CD133 gene promoter in colorectal carcinogenesis, CD133 gene promoter hypermethylation was analyzed in 32 cancer cell lines. Promoter hypermethylation was detected in 13 (40.6%) of the cell lines using methylation specificPCR and confirmed by bisulfite sequencing analysis. Treatment of 11 of the cell lines with the demethylation agent 5-aza-2’-deoxycytidine recovered CD133 expression in most of them. CONCLUSION: Transcriptional repression of CD133 is caused by promoter hypermethylation of the CD133 CpG islands in some of colorectal cancer cell lines. The study may contribute to the understanding of the role of CD133 inactivation in the progression of colorectal cancers.

关键词： CD133 Promoter Hypermethylation Colorectal cancer Sodium bisulfite modification

REE geochemistry of suspended sediments from the rivers around the Yellow Sea and provenance indicators

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

Chinese science Bulletin 2003年第11期48卷 1135-1139页

作者： YANG Shouye LI Congxian C. B. Lee T. K. Na Laboratory of Marine Geology Tongji UniversityLaboratory of Marine Geology Tongji UniversitySchool of Earth and Environment of Sciences Seoul National UniversitySchool of Earth and Environment of Sciences Seoul National University Shanghai 200092 ChinaShanghai 200092 ChinaSeoul 151-742 KoreaSeoul 151-742 Korea

Rare earth element (REE) compositions of the suspended sediments from the rivers around the Yellow Sea were different in that korean river sediments (Han, Keum and Yeongsan Rivers) yield stronger fractionations than Chinese river sediments (Changjiang, Huanghe and Yalujiang), shown by obvious enrichments of LREE (light rare earth element) relative to UCC (upper continental crust). Variations of source rock compositions in the drainage basins are responsible for the differences of REE compositions between the river sediments. REE fractionation parameters including (La/Yb)UCC and (Gd/Yb)UCC as well as the ratios of La/Sc and Th/Sc can be treated as proper proxies for identifying the Chinese river sediments from those korean river matters, and furthermore, for studying the provenances and paleoenvironmental changes of the marginal seas of China.

关键词：地球化学黄海稀有元素 REE 沉积物中国韩国