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Time series analysis of mantle cycles Part Ⅱ:The geologic record in zircons, large igneous provinces and mantle lithosphere

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Geoscience Frontiers 2019年第4期10卷 1327-1336页

作者： Kent c. condie Stephen J. Puetz Department of Earth & Environmental Science New Mexico Institute of Mining and TechnologySocorroNM87801USA Progressive Science Institute HonoluluHI96815USA

Igneous and detrital zircons have six major U/Pb isotopic age peaks in common(2700 Ma,1875 Ma.1045 Ma,625 Ma,265 Ma and 90 Ma).For igneous rocks,each age peak is comprised of subpeaks with distinct geographic distributions and a subpeak age range per age peak≤100 *** are eight major LIP age peaks(found on≥10 crustal provinces)of which only four are in common to major detrital zircon age peaks(2715 Ma,1875 Ma,825 Ma,90 Ma).Of the whole-rock Re depletion ages,58%have correspo nding detrital zircon age peaks and 55%have corresponding LIP age *** age pea ks are fou nd in common to igneous zircon,detrital zircon,LIP,and Re depletion age time series(3225 Ma,2875 Ma,2145 Ma,2085 Ma,1985 Ma,1785 Ma,1455 Ma,1175 Ma,825 Ma,and 90 Ma).and these are very robust peaks on a global scale as recorded in both crustal and mantle *** 50%of the age peaks in each of these time series correspond to predicted peaks in a 94-Myr mantle cycle,including four of the ten peaks in common to all four time series(2875 Ma,1785 Ma,825 Ma and 90 Ma).Age peak widths and subpeak ranges per age peak suggest that mantle events responsible for age peaks areyr and manyyr in *** peak geographic distributions show three populations(≤1000 Ma,2500-1000 Ma,>2500 Ma),with the number of new provinces in which age peaks are represented decreasing with time within each *** breaks between the populations(at 2.5 Ga and 1 Ga)fall near the onsets of two transitions in Earth *** First Transition may represent a change from stagnant-lid tectonics into plate tectonics and the Second Transition,the onset of subduction of continental *** major factor controlling geographic distribution of age peaks is the changing locations of ***^2 Ga,age subpeaks and peaks are housed in orogens within or around the edges of crustal provinces,mostly in accretionary *** beginning at 1.9 Ga,collisional orogens become more *** coincidence in duration

关键词： Isotopic age peaks U/Pb zircon ages Re depletion ages Large igneous provinces Age peak correlation Mantle cycles

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THE EFFEcT OF MAGNETIc FIELDS ON LOW FREQUENcy OScILLATING NATURAL cONVEcTION WITH PRESSURE GRADIENT

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Applied Mathematics and Mechanics(English Edition) 2003年第3期24卷 274-283页

作者： G.c.Sharma Madhu Jain Mahesh chandra School of Mathematical Sciences Institute of Basic ScienceSchool of Mathematical SciencesInstitute of Basic ScienceSchool of Mathematical SciencesInstitute of Basic Science KhandariAgra-282002IndiaKhandariAgra-282002IndiaKhandariAgra-282002India

The oscillating natural convection in the presence of transverse magnetic field with time depending pressure gradient is studied. The analysis of the problem is carried out by assuming that the fluid is flowing in a parallel plate configuration. The emphasis is on low frequency oscillating convective flows induced by g-jitter associated with micro gravity because of their importance to the space processing materials. A general solution for an oscillating flow in the presence of transverse magnetic field is carried out. Some special cases of the oscillating flow and its response to an applied magnetic field are performed. It was observed that the behavior of oscillating free convective flows depends on frequency, amplitude of the driving buoyancy forces, temperature gradient,magnetic field and the electric conditions of the channel walls. In the absence of magnetic field, buoyancy force plays a predominant role in driving the oscillatory flow pattern, and velocity magnitude is also affected by temperature gradients. To suppress the oscillating flow external magnetic field can be used. It is also found that the reduction of the velocity is inversely proportional to the square of the applied magnetic field with conducting wall but directly proportional to the inverse of the magnetic field with insulating wall. Detailed calculations and computational results are also carried out to depict the real situation.

关键词： convection g- jitter acceleration buoyancy force magnetic field pressure gradient

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Feruloylated Arabinoxylans Are Oxidatively cross- Linked by Extracellular Maize Peroxidase but Not by Horseradish Peroxidase

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Molecular Plant 2009年第5期2卷 883-892页

作者： Sally J. Burr Stephen c. Fry The Edinburgh cell Wall Group Institute of Molecular Plant Sciences School of Biological Sciences The University of Edinburgh Daniel Rutherford Building The King's Buildings Edinburgh EH9 3JH UK Present address: Ecologie Microbienne/UMR cNRS 5557 USc INRA 1193 Universite Claude Bernard--Lyon 1 Batiment Gregor Mendel 16 rue Dubois F-69622 Villeurbanne Cedex France

covalent cross-linking of soluble extracellular arabinoxylans in living maize cultures, which models the cross- linking of wall-bound arabinoxylans, is due to oxidation of feruloyl esters to oligoferuloyl esters and ethers. The oxidizing system responsible could be H2O2/peroxidase, O2/laccase, or reactive oxygen species acting non-enzymically, To distinguish these possibilities, we studied arabinoxylan cross-linking in vivo and in vitro. In living cultures, exogenous, soluble, extracellular, feruloylated [pentosyl-3H]arabinoxylans underwent cross-linking, beginning abruptly 8 d after sub-culture. crosslinking was suppressed by iodide, an H2O2 scavenger, indicating dependence on endogenous H2O2. However, exogenous H2O2 did not cause precocious cross-linking, despite the constant presence of endogenous peroxidases, suggesting that younger cultures contained natural cross-linking inhibitors. Dialysed culture-filtrates cross-linked [^3H]arabinoxylans in vitro only if H2O2 was also added, indicating a peroxidase requirement. This cross-linking was highly ionic-strength-dependent. The peroxidases responsible were heat-labile, although relatively heat-stable peroxidases （assayed on o-dianisidine） were also present. Surprisingly, added horseradish peroxidase, even after heat-denaturation, blocked the arabinoxylancross-linking action of maize peroxidases, suggesting that the horseradish protein was a competing substrate for [^3H]arabinoxylan coupling. In conclusion, we show for the first time that cross-linking of extracellular arabinoxylan in living maize cultures is an action of apoplastic peroxidases, some of whose unusual properties we report.

关键词： cell wall cross-links phenolics ferulate peroxidase soluble extracellular polysaccharides Zea mays L.

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A Method of Inversing the Peak Density of Atomic Oxygen Vertical Distribution in the MLT Region From the OI (557.7 nm)Night Airglow Intensity

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空间科学学报 2005年第5期25卷 484-489页

作者： H. Gao J. y. Xu W. yuan Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China china-Russia Joint Research center on Space Weather Graduate School Chinese Academy of Sciences Beijing 100039

In this paper, using the MSISE-90 model as the reference atmosphere, we discuss the feasibility and method of deducing the peak densities of the undisturbed atomic oxygen profiles in the MLT region (the mesosphere and lower thermosphere region) from OI (557.7 nm) night airglow intersities. The peak densities for different seasons, latitudes and longitudes are deduced from OI (557.7nm) airglow intensities through this expression. We analyze the features of inversion relative errors and discuss the influence of the variations in temperature on inversion errors. The results indicate that all inversion errors are less than 5% except for those at high altitudes in the summer hemisphere. And the impact of the variations in temperature on errors is not significant.

关键词：原子氧 MLT 气辉天文

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Photocatalytic parameters and kinetic study for degradation of dichlorophenol-indophenol (DcPIP) dye using highly active mesoporous TiO_2 nanoparticles

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Journal of Environmental Sciences 2016年第5期28卷 26-39页

作者： H.A.Hamad W.A.Sadik M.M.Abd El-latif A.B.Kashyout M.y.Feteha Fabrication Technology Department Advanced Technology and New Materials Research Institute (ATNMRI)City of Scientific Research and Technology Applications (SRTA-City) Materials Science Department Institute of Graduate Studies and Research (IGSR) Alexandria University Electronic Materials Department Advanced Technology and New Materials Research Institute (ATNMRI)City of Scientific Research and Technology Applications (SRTA-City)

Highly active mesoporous TiO_2 of about 6 nm crystal size and 280.7 m^2/g specific surface areas has been successfully synthesized via controlled hydrolysis of titanium butoxide at acidic medium. It was characterized by means of XRD（X-ray diffraction）, SEM（scanning electron microscopy）, TEM（transmission electron microscopy）, FT-IR（Fourier transform infrared spectroscopy）, TGA（thermogravimetric analysis）, DSc（differential scanning calorimetry） and BET（Brunauer–Emmett–Teller） surface area. The degradation of dichlorophenol-indophenol（DcPIP） under ultraviolet（UV） light was studied to evaluate the photocatalytic activity of samples. The effects of different parameters and kinetics were investigated. Accordingly, a complete degradation of DcPIP dye was achieved by applying the optimal operational conditions of 1 g/L of catalyst, 10 mg/L of DcPIP, pH of 3 and the temperature at 25 ± 3°c after 3 min under UV irradiation. Meanwhile, the Langmuir–Hinshelwood kinetic model described the variations in pure photocatalytic branch in consistent with a first order power law *** results proved that the prepared TiO_2 nanoparticle has a photocatalytic activity significantly better than Degussa P-25.

关键词： Photocatalytic degradation Mesoporous TiO2 Kinetics Organic dye

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A Theoretical Approach for Estimating Fracture Toughness of Ductile Metals

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上海交通大学学报 2004年第Z2期38卷 114-119页

作者： y.T. He F. Li G.Q. Zhang L.J. Ernst X.J. FU college of Aeronautics University of Air Force Engineering Xi''an 710038 China college of Aeronautics Northwestern Polytechnical University Xi''an710072 China College of Aeronautics University of Air Force Engineering Xi''an 710038 China Philips Centre for Industrial Technology P.O.Box 218 5600 MD Eindhoven The Netherlands Delft University of Technology 2628 CD Delft The Netherlands College of Aeronautics Northwestern Polytechnical University Xi''an 710072 China

Fracture toughness is very important when applying Damage Tolerance Design and Assessment Techniques. The traditional testing approach for obtaining fracture toughness values is costly and time consuming. In order to estimate the fracture toughness of ductile metals, the fracture mechanics theory, materials plastic deformation theory and materials constructive relationships are employed here. A series of formulae and a theoretical approach are presented to calculate fracture toughness values of different materials in the plane stress and plane strain conditions. compared with test results, evaluated values have a good agreement.

关键词： fracture toughness testing approach evaluated method fracture mechanics theory plastic deformation theory materials constructive relationship theoretical approach

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基于DSpace的Lib2.0

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大学图书馆学报 2006年第3期24卷 2-5页

作者：叶鹰黄晨浙江大学杭州310028

指出用户互动是Web2.0和Lib2.0的典型特征,提出以开源软件系统DSpace作为数字图书馆核心引擎的Lib2.0模型。综合资源、技术和服务管理讨论了基于DSpace构建Lib2.0的技术可能性和应用优越性,并论及与Lib2.0相应的Librarian2.0。

关键词： DSpace Lib 2.0 图书馆2.0 图书馆员2.0 数字图书馆

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DyNAMIc cOMPAcTION OF PURE cOPPER POWDER USING PULSED MAGNETIc FORcE

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Acta Metallurgica Sinica(English Letters) 2007年第4期20卷 277-283页

作者： H.P. yu c.F. Li National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology Harbin 150001 China

The compaction of pure cu powder was carried out through a series of experiments using dynamic magnetic pulse compaction, and the effects of process parameters, such as discharge energy and compacting direction, on the homogeneity and the compaction density of compacted specimens were presented and discussed. The results indicated that the compaction density of specimens increased with the augment of discharge voltage and time. During unidirectional compaction, there was a density gradient along the loading direction in the compacted specimen, and the minimum compaction density was localized to the center of the bottom of the specimen. The larger the aspect ratio of a powder body, the higher the compaction density of the compacted specimen. And high conductivity drivers were beneficial to the increase of the compaction density. The iterative and the double direction compaction were efficient means to manufacture the homogeneous and high-density powder parts.

关键词： magnetic pulse compaction copper powder compaction density electromagnetic forming

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Development of anti-corrosive coating on AZ31 Mg alloy subjected to plasma electrolytic oxidation at sub-zero temperature

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Journal of Magnesium and Alloys 2022年第7期10卷 1915-1929页

作者： S.Fatimah M.P.Kamil D.I.Han W.Al-Zoubi y.G.Ko Materials Electrochemistry Group School of Materials Science and EngineeringYeungnam UniversityGyeongsan 38541Republic of Korea

Plasma electrolytic oxidation(PEO)is a promising surface treatment to generate adherent and thick anti-corrosive coating on light-weight metals(Al,Mg,Ti,etc.)using an eco-friendly alkaline *** energy plasma,however,inevitably generates porous structures that limit their practical *** present study proposes a straight-forward simple method by utilizing sub-zero electrolyte(268 K)to alter the plasma characteristics during formation of the protective coating on AZ31 Mg alloy via PEO with a comparison to the electrolyte at room temperature(298 K).In refrigerated electrolyte,the formation of micro-defects is suppressed relatively at the expense of low coating growth,which is measured to be twice lower than that at 298 K due to the temperature-dependent soft plasma discharges contributing to the development of the present *** a consequence,corrosion resistance of the sample processed at 268 K is superior to that of 298K,implying that the effect of coating thickness is less dominant than that of *** phenomenon is interpreted in relation to the ionic movement and oxide solidification controlled by soft plasma discharges arising from the temperature gradient between electrolyte and surface of the substrate during PEO.

关键词： AZ31 Mg alloy Plasma electrolytic oxidation Sub-zero electrolyte Anti-corrosive coating corrosion

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Analysis and design of axially loaded piles in rock

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第3期11卷 535-548页

作者： c.M.Haberfield A.L.E.Lochaden Golder Associates Pty.Ltd. MelbourneAustralia

Despite significant advancements in in situ test techniques,construction practices,understanding of rock joint and rock mass behaviours,and numerical analysis methods,the design of bored concrete cast-insitu piles in rock is still largely based on the assessment of bearing ***,for many of the rock conditions encountered,the bearing capacity of piles is a nebulous concept and a figment of the designer’s *** if it can be reasonably quantified,it has little,if any,significance to the performance of a pile in *** load carrying capacity of even low strength rock(in most situations)is far in excess of the strength of the structure(for example,a building column)transmitting the *** performance of a pile in rock is usually a displacement issue and is a function of rock mass stiffness rather than rock mass *** addition,poor pile performance is much more likely to result from poor construction practices than excessive displacement of the rock *** occur for footings that are undermined,or where unfavourable structure in the rock allows movement towards a free surface to ***,codes of practices,reference books and other sources of design information should focus foundation design in rock on displacement rather than strength *** investigations should measure rock mass stiffness and defect properties,as well as intact rock *** paper summarises the fundamental concepts relating to performance of piles in rock and provides a basis for displacement focused design of piles in *** also presents comments relating to how piles are modelled in widely used commercial finite element software for soil-structure interaction analysis,within the context of the back-analysis of a pile load test,and proposes recommendations for pile analysis and design.

关键词： Pile design Pile analysis Pile load test Finite element analysis

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