检索结果-南通市图书馆

Petrology and mineral chemistry of new ureilites found in Grove Mountains, Antarctica

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:materials international 2008年第4期18卷 431-439页

作者： Bingkui Miaoa,b,, Yangting Linb, Guiqin Wangc, Daode Wangc, Ziyuan Ouyangd a Key Laboratory of Geological Engineering center of Guangxi Province, Guilin University of Technology, Guilin 541004, china b State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geo{2., chinese academy of sciences, Beijing 10002., china c Key Laboratory of Isotope Geochronology and Geochemistry, Guangzhou Institute of Geochemistry, chinese academy of sciences, Guangzhou 510640, chinad National Astronomical Observatories, chinese academy of sciences, Beijing 100012. china Key Laboratory of Geological Engineering center of Guangxi Province Guilin University of Technology Guilin 541004 China State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

Petrography and mineral chemistry of two new ureilites, GRV 02.512.and 02.931, from the Grove Mountains, Antarctica, are reported in this paper. GRV 02.512.exhibits a typical ureilite texture, and consists of 48.3% olivine, 9.4% pigeonite and 38.1% carbo- naceous interstitial material and/or reduction product. GRV 02.931 has a cataclastic porphyritic texture, and consists of 19.1% olivine and 14.1% pigeonite embedded in 66.3% carbonaceous interstitial material and/or reduction product. The coarse-grained olivine and pigeonite in both meteorites have homogeneous cores, and they are FeO-rich within the range of the ferroan subgroup (subgroup I) of olivine-pigeonite ureilites. All olivine grains of the meteorites show reduction zones along boundaries and cracks. Abundant diamond coexists with graphite as graphite-rich patches and veins in the carbonaceous interstitial material. Petrogenesis of both meteorites and the origin of diamond are discussed.

关键词： Meteorite Achondrite Ureilite Diamond Antarctica

Chronological record of the Early Mesozoic underplating in the northern margin of North china—U-Pb chronometry of zircons in the Late Mesozoic andesite from Western Liaoning

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:materials international 2007年第8期17卷 943-947页

作者： Shao ji'an~(1,2.*) Zhang Hongfu~2.Liu Xiaoming~3 Li Zhitong~4 (1.School of Earth and Space sciences,Peking University,Beijing 100871,china 2.Institute of Geology and Geo{2. and Key Laboratory of Mineral Resources,chinese academy of sciences,Beijing 10002.,china 3.Key Laboratory of Continental Dynamics,Northwestern University,Xi'an 710069,china 4.Institute of Geology and Mineral Resources of shenyang,shenyang 110032.china) School of Earth and Space sciences Peking University Beijing 100871 China Institute of Geology and Geophysics and Key Laboratory of Mineral Resources Chinese Academy of Sciences Beijing 100029 China Key Laboratory of Continental Dynamics Northwestern University Xi'' an 710069 China Institute of Geology and Mineral Resources of shenyang Shenyang 110032 China

Cathodoluminescence spectroscopic analysis of zircons in the uppermost sanukites of the early Cretaceous Yixian Forma- tion in Western Liaoning reveals zoning structures of the zircons in the volcanic rocks. LA-ICP-MS chronometry shows that the central part of the zircons is remnant zircon with a U-Pb dating of 2.4 Ma,which is consistent with the age of the Early Mesozoic underplating granulites,and that the periphery is zircon crystallizing out of the host magma with a U-Pb dating of 116 Ma,which is highly consistent with the Ar-Ar dating of the host volcanic *** of the clinopyroxenes xenocrystals in the sanukites are similar to those of the clinopyroxenes in the underplating granulites,indicating that the granulites accreted to the lower crust in the Early Mesozoic have been reformed and disrupted by the upwelling diapers of the asthenosphere and taken part in formation of the sanukites in the Late Mesozoic.

关键词： northern margin of North china Mesozoic volcanic rock U-Pb chronometry of zircon underplating granulite

Employing SiO_2.Buffer Layer to Improve Adhesion of the Frequency-doubled Antireflection Coating on LBO

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(materials Science) 2009年第6期24卷 849-851页

作者：谭天亚 Department of physics Liaoning University

Frequency-doubled antireflection coatings simultaneously effective at 1064 nm and 532.nm were deposited on the lithium triborate （LiB3O5 or LBO） crystals using the electron beam evaporation method. Comparing with the sample without buffer layer, it is found that the adhesion of the sample with buffer layer of SiO2.between coating and LBO substrate is improved significantly from 137.4 mN to greater than 2.0 mN. And the laser-induced damage threshold is increased by 2.% from 15.1 J/cm^2.to 18.6 J/cm^2. The strengthening mechanism of adhesion of the buffer layer of SiO2.is discussed by considering full plastic indentation and shear theory.

关键词： frequency-doubled antireflection coating LBO crystal adhesion

The qanats of Xinjiang:historical development, characteristics and modern implications for environmental protection

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2012年第2期4卷 211-220页

作者： WenJun HU1 ,2.JieBin ZHANG 3,YongQiang LIU 1 1Hohai University,Nanjing 2.0098,china 2.he international Economic&Technical Cooperation and Exchange {2.,Ministry of Water Resources,Beijing 100053, china 3 Xinjiang Institute of Ecology and Geography,chinese academy of sciences,Urumqi 830011,china Hohai University The international Economic & Technical Cooperation and Exchange center Ministry of Water Resources Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences

In china,qanats(kan’erjing/karez)exist only in Xinjiang Uygur autonomous region,being one form of traditional irrigation technology that made great contributions to oasis *** are different opinions on the origin and date of the qanats in Xinjiang due to a lack of adequate *** uncontrolled over-exploitation of groundwater by pumping wells,as well as the expansion of surface water interventions nowadays,has caused serious impacts on not only the qanats,but also local ecological *** exist long-time arguments on whether the qanats should be restored or *** study aimed to examine the historical development, geological conditions and characteristics,and modern implications of the qanats for oasis environmental protection, and to discuss the initiatives taken by local *** whole Xinjiang Uygur autonomous region was included as the study area,with a specific focus on Turpan *** materials and data were obtained from literature review and governmental *** on a systematic examination of three prevailing theories on the origination of Xinjiang’s qanats,it is suggested modern archaeological techniques could be good solutions to explore the origination in addition to historical records used *** qanats fail to fully meet today’s enormous water demands,their rich historical,cultural,ecological and environmental implications in arid areas should not be *** a cultural heritage and ecologically-friendly engineering creation,qanat systems shall be kept in good condition and function by a valuable *** initiatives to protect and restore target qanat systems in Xinjiang could provide positive examples for the practices in other regions of the world where the protection and restoration of qanats or similar technologies are desired.

关键词： arid areas qanat(kan’erjing/karez) groundwater environmental protection oasis Xinjiang

Densification and Microstructure of β-sialon/Nano-size SiC Composites

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 1997年第4期13卷 339-341页

作者： Cheng ZHANG Danyu JIANG Qiang LI and Weiying SUN (Shanghai Institute of Ceramics, chinese academy of sciences, Shanghai 2.0050, china) Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China

β-sialon/nano-size SiC composite ceramic with DyAG(Dy3Al5O12. as grain boundary phase was fabricated through hot-pressing. The effect of nano-size SiC on densification, phase composition, microstructure and mechanica... 详细信息

关键词： Nano SiC Densification and Microstructure of sialon/Nano-size SiC Composites

Tape Casting of Al_2._3-TiB_2.Al_2._3-Nano-TiC Multilayer Composites

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 1997年第4期13卷 324-326页

作者： Yuping ZENG Dongliang JIANG Shouhong TAN and Jingkun GUO(Shanghai Institute of Ceramics, chinese academy of sciences, Shanghai 2.0050, china) Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China

Ceramic tapes, containing Al2.3-2. wt pct TiB2.B) and Al2.3-2. wt pct nano-TiC (c), have been obtained by tape casting process. Numerous tapes (about 60～80 tapes) were prepared by stacking in turn the composition (B) and (C), laminating under 10 MPa pressure, eliminating the solvent and burning out the polymer additives. The final green bodies were hot pressed at 1750℃ and 30 MPa. The composite has a bending strength of 568 MPa and a fracture toughness of 5.8 M Pa·m1/2. SEM analysis exhibits that Al2.3 particle growth was inhibited by TiC particles in C. but TiB2.particles could not hinder Al2.3 growth in B. The curves of GTA indicates that all organic additives could be removed completely above 600℃

关键词： Nano TiB Al Tape Casting of Al2.3-TiB2.Al2.3-Nano-TiC Multilayer Composites TiC

Effect of fabrication parameters on the microstructure,in-plane anisotropy and magnetostriction of Fe-Ga thin films

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2010年第6期29卷 583-588页

作者： WANG Bowen HUANG Wemnei CAO Shuying DU Yong HE Yuehui HUANG Baiyun Province-Ministry Joint Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability Hebei University of TechnologyTianjin 300130China international center for {2. physics Chinese Academy of SciencesShenyang 110015China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

The microstructure,in-plane anisotropy,and magnetic properties of Fe-Ga thin films were investigated by X-ray diffraction analysis,vibrating sample magnetometer,and capacitive cantilever *** in-plane induced anisotropy is well formed by the applied magnetic field during sputtering,and the anisotropy field Hk decreases with the sputtering power *** coercivity of Fe-Ga thin films decreases with increasing power when the sputtering power is less than 60 W and increases when the power is larger than 60 *** magnetostriction of the thin films reaches 66 × 10-6 at the sputtering power of 60 *** Fe-Ga films,which exhibit good field sensitivity,low coercivity and high magnetostriction,have been fabricated at the power of 60 W,and they can be used as the materials of magnetostrictive transducers.

关键词： metallic thin films magnetostriction magnetron sputtering anisotropy

在线全文

学校读者我要写书评

暂无评论

电磁场曝露对生物组织电磁特性的影响

生物化学与生物物理进展 2011年第7期38卷 604-610页

作者：李滚庞小峰电子科技大学生命科学与技术学院生物物理与生物电子学实验室成都610054 中国科学院国际材料物理中心沈阳110015

电磁辐射严重影响着人体的健康.电磁场生物效应的发生机制与电磁场本身的特性相关,同时也与生物组织在电磁场作用下电磁特性的改变密切相关.生物体内的信号分子、自由基以及磁颗粒等处于外加电磁场中时其电磁特性会发生变化,尤其是不同... 详细信息

电磁辐射严重影响着人体的健康.电磁场生物效应的发生机制与电磁场本身的特性相关,同时也与生物组织在电磁场作用下电磁特性的改变密切相关.生物体内的信号分子、自由基以及磁颗粒等处于外加电磁场中时其电磁特性会发生变化,尤其是不同频率电磁场曝露作用下生物组织的导电、介电以及磁学等特性会有非常显著的区别.明确不同频率电磁场作用下生物组织电磁特性的变化规律是研究电磁场生物效应发生机制以及预防问题的关键.综述了近年来电磁场对于生物组织电磁特性影响的研究成果,并对未来的研究方向做了展望.

关键词：电磁辐射生物效应生物组织电磁特性

Influence of nanometric CeO2.coating on high temperature oxidation of Cr

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:materials international 2007年第5期17卷 601-606页

作者： Jin Huiming , Zhang Linnan and Liu Xiaojun (materials Research center, Department of Mechanical Engineering, Yangzhou University, Yangzhou 2.5009,{2. College of materials Science and Engineering, North-East University, shenyang 110014,{2.) materials Research center Department of Mechanical Engineering Yangzhou University Yangzhou 225009 China Laboratoire de magnetisme Louis Neel 25 avenue des Martyrs 38042 Grenoble cedex 9 France

Isothermal and cyclic oxidation behavior of chromium and its superficially applied nanometric CeO2.samples were studied at 900℃in air. Scanning electronic microscopy (SEM), transmission electronic microscopy (TEM) and high resolution electronic microscopy (HREM) were used to examine the morphology and micro-structure of oxide films. It was found that ceria addition greatly improved the anti-oxidation ability of Cr both in isothermal and cyclic oxidizing experiments. Acoustic emission (AE) technique was used in situ to monitor the cracking and spalling of oxide films, and AE signals were analyzed in time-domain and number-domain according to the related oxide fracture model. Laser Raman spectrometer was also used to study the stress status of oxide films formed on Cr with and without ceria. The main reason for the improvement in anti-oxidation of chromium was that ceria greatly reduced the growing speed and grain size of Cr2.3. This fine-grained Cr2.3 oxide film might have better high temperature plasticity and could relieve parts of compressive stress by means of creeping, and maintained the ridge character and relatively low internal stress level. Meanwhile, ceria application reduced the size and the number of interfacial defects, while remarkably enhanced the adhesive property of Cr2.3 oxide scale formed on Cr substrate.

关键词： oxidation stress CeO2.nanoparticle coating chromium.