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Thermally induced inversion of Al-substituted titanomagnetite in basalts:Evidence for partial self-reversal

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Thermally induced inversion of Al-substituted titanomagnetit...

中国科学院地质与地球物理研究所2006学术年会

作者： Yongxin Pan~1,Qingsong Liu~2,Chenglong Deng~1,Huafeng Qin~1,and Rixiang Zhu~1 (1 Paleomagnetism and Geochronology Laboratory,Institute of Geology and Geophysics,chinese academy of sciences,beijing,china.2 national Oceanography Centre,University of Southampton,Southampton,UK.)

We report properties of laboratory-induced thermoremanence combined with detailed rock magnetic experiments on basaltic samples which contain aluminum-substituted titanomagnetite(Fe2.24Ti0.64A10.12O4).Prior to Thellier-Coe paleointensity experiments, specimens were first demagnetized using an alternating field with a peak field of 90 Mt and were then imparted an anhysteretic remanent magnetization(ARM) to represent a natural remanent magnetization(NRM).Results show that the partial thermal remanent magnetization(pTRM) gain and ARM remaining are linearly correlated up to *** 300 and 460,specimens acquire thermoremanence with a direction antiparallel to the external field direction,leading to intensity *** coincides with the onset of the mineral transformation from Al-titanomagnetite to a magnetic phase with higher *** results support that phase interaction with distinct Tc values in partially oxidized titanomagnetite can produce partial self-reversal thermoremanence in rocks

关键词： titanomagnetite partial self-reversal

The Design and Self-assembly of Anion Receptors Based on 1,2,3-Triazole

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The Design and Self-assembly of Anion Receptors Based on 1,2...

中国化学会第六届全国结构化学学术会议

作者： Yong-Jun Li~1,Hui-Biao Liu~1,Yu-Liang Li~(1,*) 1 CAS Key Laboratory of Organic Solid,beijing national Laboratory for Molecular sciences (BNLMS),Institute of Chemistry,chinese academy of sciences,beijing 100190,P.R. china.

＜正＞Anions play important chemical and biological roles,and the supramolecular chemistry involving them has grown *** developments range from fundamental studies on noncovalent bonding to the design of anion receptors and anion assistance to asymmetric *** triazole was distinguished from other ring systems by the relief of steric strain provided by the sp2 nitrogen atoms,which is an excellent unit for the construction of *** collective effect of the preorganized shape,the ideal size of the inner

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Multiple mineralization events in the eastern Tianshan district,NW china:Isotopic geochronology and geological significance

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Multiple mineralization events in the eastern Tianshan distr...

中国科学院地质与地球物理研究所2008学术年会

作者： Lianchang Zhang~(a,*),Kezhang Qin~a,Wenjiao Xiao~b a Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,chinese academy of sciences,P.O.BOX 9825,beijing 100029,china b State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,chinese academy of sciences,P.O.BOX9825,beijing 100029,china

The eastern Tianshan district occupies the middle of the Central Asian Oogenic Belt and has great economic potential for polymetallic *** than 20 medium to large ore deposits have been discovered in this region since the late *** timing of mineralization was previously thought to be Hercynian,but,Mesozoic ages for intrusions and mineralization have been repeatedly reported in recent *** on geochronological data and regional geological evidence,it is suggested that the mineralization in the eastern Tianshan was formed during multiple *** mineralization processes are related to an subduction-island arc stage (～360-320 Ma) with porphyry-type and volcano-sedimentary copper deposits,a collisional-accretionary stage(～300-280 Ma) with orogenic -type gold deposits,a post-collisional-extension stage(～280-245 Ma) with mafic-ultramafic copper-nickel and epithermal gold deposits,and an intracontinental extensional stage(～240-220 Ma) that gave rise to the Jinwuozi gold deposit,Xiaobaishitou skarn W-Mo deposit and Baishan porphyry Mo-Re deposit.

关键词： East Tianshan Porphyry-type deposits Orogenic-type deposits Multiple mineralization Central Asian Orogenic Belt

Evidence for decreasing South Asian summer monsoon in the past 160 years from varved sediment in Lake Xinluhai,Tibetan Plateau

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Evidence for decreasing South Asian summer monsoon in the pa...

中国科学院地质与地球物理研究所第11届（2011年度）学术年会

作者： Guoqiang Chu,Qing Sun,Ke Yang,Aiguo Li,Xiaohan Yu,Tao Xu,Fen Yan, Hua Wang,Meimei Liu,Xiaohua Wang,Manman Xie,Yuan Lin,and Qiang Liu 1Key Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,chinese academy of sciences,beijing,china. 2 national Research Center of Geoanalysis,beijing,china. 3 Shanghai Synchrotron Radiation Facility,Shanghai Institute of Applied Physics,chinese academy of sciences,Shanghai,china.

[1]We report glacial varves in the sediment of Lake Xinluhai,Tibetan Plateau. Independent data of Cs and Pb indicate that these are annually deposited varves, Varves appear as rhythmic units of light-colored silt layer capped by a dark clay layer under *** thickness in Lake Xinluhai is sensitive to precipitation because sediment accumulation is strongly affected by monsoon rainfall in the area.A general decreasing trend can be observed in the varve thickness over the past 160 *** analyses of the varve record are dominated by cycles which are similar to ENSO *** implies that the decreasing trend of the South Asia monsoon may be linking with ***,the decreasing trend can be observed across different proxy records in the south of the Tibetan *** arguments still remain for the dynamic mechanisms and spatial rainfall difference,the South Asian summer monsoon could be weakened due to rising temperatures.

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Influence of Aluminum Content in γ-TiAl with L1_0 Structure during Ordering Processes

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Rare Metals 2001年第4期20卷 230-235页

作者： Timothée Nsongot1,2 Xiaodong Ni1,3 Guoliang Chen1, Keh-Minn Chang4 1) State Key Laboratory for Advanced Metals and Materials, University of Science and Technology beijing, beijing 100083, china 2) Faculty of Science, P. 0. Box 69, Brazzaville, Congo 北京科技大学新金属材料国家重点实验室北京 100083 West-Virginia University 美国

Based on EAM (embedded atom method) interatomic potential, the effect of aluminum content on the type of order-disorder transformation (ODT) and the structure properties (lattice constants, volume, c/a ratio and configu- ration energy) during ordering processes was investigated for γ-TiAI based alloys. Results show that for the alloys with lower than 50%Al (all composition is in atom number fraction), the ODT is the first order transition, and the second order transition for the alloys with equal or higher than 50% Al. The increase of aluminum content results in the critical temperature increasing. The aluminum content has a very little effect on the lattice constants, the volume and the c/a ratio, but has a significant effect on the configuration energy. A metastable disordered state was found for the alloys with less than 50%Al.

关键词： TiA1 order-disorder transformation long-range order

The yield and quality of biomass regulated by flowering genes in Arabidopsis

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The yield and quality of biomass regulated by flowering gene...

国际生物质能与生物技术学术会议

作者： Yong-Fu Fu Ting Yu Xu Wang Institute of Crop sciences The national Key Facility for Crop Gene Resources and Genetic Improvement(NFCRI ) chinese academy of Agricultural sciences Nandajie12 Zhongguancun Haidian District beijing 100081 P.R.china.

＜正＞Biofuel is the most promising energy alternative to fossil fuels because it represents an abundant carbon-neutral renewable resource,reduces greenhouse gas（GHG） emissions and addresses several societal needs such as enhancing rural *** is one of most common biofuels,and two primary kinds of feedstock,sugar/starch from corn grain and other

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On Robust Stability of a Class of Uncertain Nonlinear Systems with Time-Varying Delay

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Systems Science and Systems Engineering 2002年第2期11卷 129-135页

作者： NIAN Xiao-hongDepartment of Mechanics and Engineering sciences, Peking University,beijing 100871 , china Institute of Information and Control Engineering,Central South University, Changsha 410075, china Department of Mechanics and Engineering sciences Peking UniversityBeijing 100871 China Institute of Information and Control Engineering Central South University Changsha 410075 China

The problem of robust stability of a class of uncertain nonlinear dynamical systems with time-delay is considered. Based on the assumption that the nominal system is stable, some sufficient conditions on robust stability of uncertain nonlinear dynamical systems with time-delay are derived. Some analytical methods and a type of Lyapunov functional are used to investigate such sufficient conditions. The results obtained in this paper are applicable to perturbed time-delay systems with unbounded time-varying delay. Some previous results are improved and a numerical example is given to demonstrate the validity of our results.

关键词： robust stability nonlinear time-delay uncertainty

FIVE MODE INTERACTIONS IN A FREE SHEAR LAYER

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Journal of Hydrodynamics 1998年第3期10卷 45-61页

作者： Taewon SeoSchool of Mechanical Eng. ,Andong national Univ. , South KoreaWang Xing-kui, Wang Guang-qianDepartment of Hydraulic Eng. ,Tsinghua Univ. , beijing 100084, P.R.china Andong Natl Univ Andong South Korea

This study condiders spatially developing free shear layers at moderate Reynolds numbers that are formed by the merging of two free streams initially separated by a splitter plate. To study the nonlinear interactions between the two- and three-dimensional fundamental and subharmonic modes in the spatially developing shear layer, the selected five modes represent the minimum number that needs to be considered. The objective of this study is to investigate the nonlinear effects arising from the interactions between two- and three-dimensional large-scale coherent structures in a free shear layer. Our attention is focused on the energy exchange mechanisms between the various modes, and the effects of the nonlinear evolution of the phases of the interacting modes. It is shown that depending on the initial modal phase angles the downstream growth of the shear layer and the associated local entrainment can be strongly affected by the presence of these nonlinear interactions. This high sensitivity of the shear layer growth is limited to a narrow band of initial phase angle values.

关键词： model interaction free shear layer

LOW TEMPERATURE ALUMINUM FLOATING ELECTROLYSIS IN HEAVY ELECTROLYTE Na_3AlF_6-AlF_3-BaC1_2-NaCl BATH SYSTEM

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Acta Metallurgica Sinica(English Letters) 2000年第4期13卷 949-954页

作者： H.M. Lu and K.M. Fang Metallurgy School, University of Science and Technology beijing, beijing 100083, china Z.X. Qiu Department of Nonferrous Metallurgy, Northeastern University, Shenyang 110006, china beijing Univ of Science and Technology Beijing China

Multiple regression equations of liquidus temperature, electrical conductivity and bath density of the Na_3AlF_6-AlF_3-BaC1_2-NaCl system were obtained from experiments by using orthogonal regression method. The experiments were carried out in 100A cell with low melting point electrolyte, the influences of cathodic current density, electrolytic temperature, density differences of bath and liquid aluminum on current efficiency (CE) were studied; when the electrolyte cryolite ratio was 2.5, w(BaC1_2) and w(NaCl) were 48% and 10%, respectively, CE reached 90% and specific energy consumption was 10.97k Wb/kg/kg. Because of the fact that aluminum metal obtained floated on the surface of molten electrolyte, this electrolysis method was then defined as low temperature aluminum floating electrolysis. The results showed that the new low temperature aluminum electrolysis process in the Na_3AlF_6-AlF_3-BaC1_2-NaCl bath system was practical and promising.

关键词： low temperature aluminum floating electrolysis Na_3AlF_6- AlF_3BaC1_2-NaCl bath system current efficiency physico-chemical property