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Time series analysis of mantle cycles Part Ⅰ:Periodicities and correlations among seven global isotopic databases

Geoscience Frontiers 2019年第4期10卷 1305-1326页

作者： Stephen j. Puetz Kent c. condie Progressive Science Institute HonoluluHI96815USA New Mexico Institute of Mining and Technology SocorroNM87801USA

In this study,seven isotopic databases are presented and analyzed to identify mantle and crustal episodes on a global scale by focusing on periodicity ranging from 70 to 200 million years(Myr).The databases are the largest,or among the largest,compiled for each type of data-with an obj.ctive of finding some samples from every region of every continent,to make each database as global as conceivably *** databases contain zircon Lu/hf isotopic data,whole-rock Sm/Nd isotopic data,U/Pb detrital zircon ages,U/Pb igneous zircon ages,U/Pb non-zircon ages,whole-rock Re/Os isotopic data,and large igneous province *** I of this study focuses on the periodicities of age histograms and geochemical averages developed from the seven databases,via spectral and cross-correlation *** physical cycles often propagate in exact integer multiples of a fundamental cycle,referred to as *** tests show that harmonic geological cycles of^93.5 and^187 Myr have persisted throughout terrestrial history,and the cyclicities are statistically significant for U/Pb igneous zircon ages,U/Pb detrital zircon ages,U/Pb zircon-rim ages,large igneous province ages,meanεhf(t)for all samples,meanεhf(t)values for igneous-only samples,and relative abundance of mafic *** important,cross-correlation analyses show these seven time-series are nearly synchronous(±7 Myr)with a model consisting of periodicities of 93.5 and 187 ***,the similarities between peaks in the 93.5 and 187 Myr mantle cycles and terminal ages of established and suspected superchrons provide a framework for predicting and testing superchron periodicity.

关键词： Zircon Database Isotope Statistical analysis Spectral analysis cross correlation

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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 maj.r 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 maj.r LIP age peaks(found on≥10 crustal provinces)of which only four are in common to maj.r 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 arehic 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 *** maj.r 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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Effect of Solute contents of Al-Ni-Sr Alloy on Glass Forming Ability and Thermal Stability

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j.urnal of Rare Earths 2004年第z2期22卷 73-77页

作者： Taek Soo Kim j.K Lee h j.Kim j.c Bae Advanced Materials R&D center Korea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea

Glass forming ability (GFA) and structural characterization of a new amorphous Al-Ni-Sr alloy melt spun were investigated on the theory of the factors for the glass formation. The GFA was varied with the ratio of Ni to Sr in detail and successful amorphous phase dispersed with 2 ～ 5 nm precipitates was prepared from Al-Ni5-Sr3. Thermal stability and crystallization behavior of the amorphous phase were determined by continuous and isothermal heating technique on DcS, resulting that the crystallization occurs by the growth of fcc Al nanocrystals on the preexistent nuclei.

关键词： glass formation crystallization Al base amorphous alloys rapid solidification

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coating behavior and surface hardening of Pd_(77)cu_6Si_(17) thin film metallic glass on AZ31 magnesium alloy

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j.urnal of Zhej.ang University-Science A(Applied Physics & Engineering) 2013年第12期14卷 898-905页

作者： X.h.DU Y.c.chANG h.j.PEI B.Y.chEN M.c.KUO j.c.hUANG School of Materials Sciences and Engineering Shenyang Aerospace University Department of Materials and Optoelectronic Science National Sun Yat-Sen University Department of Materials Engineering Kun Shan University

Pd77cu6Si17(PcS) thin film metallic glasses(TFMGs) with high glass forming ability and hardness were selected as a hard coating for improving the surface hardness of AZ31 magnesium alloy. Both microindentation and nanoindentation tests were conducted on specimens with various PcS film thicknesses from 30 to 2000 nm. The apparent hardness and the relative indentation depth(β) were integrated using a quantitative model. The interaction parameters involved and relative hardness values were extracted from iterative calculations. According to the results, surface hardness can be enhanced greatly by PcS TFMGs in the shallow region, followed by gradual decrease with increasing β ratio. In addition, specimens with thinner coatings(e.g., 200nm) showed greater substrate-film interaction and those with thick coatings(e.g., 2000nm) became prone to film cracking. The optimum TFMG coating thickness in this study was estimated to be around 200 nm.

关键词： Thin film metallic glass(TFMG) Magnesium alloy Sputtering process Nanoindentation coating thickness

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EFFEcT OF ANNEALING ON DAMPING cAPAcITIES OF AS-cAST ZA27 ALLOY

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Acta Metallurgica Sinica(English Letters) 2006年第5期19卷 379-384页

作者： Z.M. Zhang j. c. Wang h.Z. Liu X.F. Guo School of Materials Science ＆ Engineering Xi＇an University of TechnologyXi＇an 710048 China State Key Laboratory of Solidification Processing Northwestern PolytechnicalUniversity Xi＇an 710072 China

ZA27 alloy was prepared by casting with permanent mold and then annealed at 250℃ for 1-4h. The damping capaciG of the alloy was measured using a testing apparatus based on the cantilever beam technique. It was found that the as-cast ZA27 alloy possesses high damping capacity with the value of 1.3 × 10^4 at 320hz. After annealed at 250℃ for lh, the damping capacity decreases to 1.1 × 10^-3 and then remains constant even when the annealing time is increased to 4h. The microstructure of the as-cast ZA27 alloy consists of large dendrites of Al-rich PrimaG （x-phases, eutectoid （α ＋ η） and nonequilibrium eutectic phases （α ＋ η ＋ ε）. After annealing at 250℃ for lh, the e phase disappears due to dissolution into the matrix, and the spacing between the flakes of eutectoid increases. The further increase in the annealing time has little effect on the spacing. The damping mechanism of the alloy was discussed considering the thermoelastic damping and defect damping. The value of thermoelastic damping accounts only for 7%-8% in the overall damping in cantilever beam damping measurements and the damping capacity of the ZA27 alloy came mainly from defect damping.

关键词： damping capacity ZA27 alloy annealing

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Ultra‑Transparent and Multifunctional IZVO Mesh Electrodes for Next‑Generation Flexible Optoelectronics

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Nano-Micro Letters 2025年第1期17卷 293-309页

作者： Kiran A.Nirmal Tukaram D.Dongale Atul c.Khot chenj.e Yao Nahyun Kim Tae Geun Kim School of Electrical Engineering Korea UniversityAnam‑ro 145Seongbuk‑guSeoulRepublic of Korea computational Electronics and Nanoscience Research Laboratory School of Nanoscience and BiotechnologyShivaji UniversityKolhapur 416004India

Mechanically durable transparent electrodes are essential for achieving long-term stability in flexible optoelectronic ***,they are crucial for applications in the fields of energy,display,healthcare,and soft *** meshes represent a promising alternative to traditional,brittle,metal oxide conductors due to their high electrical conductivity,optical transparency,and enhanced mechanical *** this paper,we present a simple method for fabricating an ultra-transparent conducting metal oxide mesh electrode using selfcracking-assisted *** this method,we produced an electrode with ultra-transparency(97.39%),high conductance(Rs=21.24Ωsq^(−1)),elevated work function(5.16 eV),and good mechanical *** also evaluated the effectiveness of the fabricated electrodes by integrating them into organic photovoltaics,organic light-emitting diodes,and flexible transparent memristor devices for neuromorphic computing,resulting in exceptional device *** addition,the unique porous structure of the vanadium-doped indium zinc oxide mesh electrodes provided excellent flexibility,rendering them a promising option for application in flexible optoelectronics.

关键词： Self-cracking template Vanadium-doped indium zinc oxide mesh Organic solar cells Organic light-emitting diodes Flexible transparent memory

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OPTIMAL AND PRESSURE-INDEPENDENT L2 VELOcITY ERROR ESTIMATES FOR A MODIFIED cROUZEIX-RAVIART STOKES ELEMENT WITh BDM REcONSTRUcTIONS

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j.urnal of computational Mathematics 2015年第2期33卷 191-208页

作者： c. Brennecke A. Linke c. Merdon j. Schoberl Eidgen6ssische Technische hochschule Ziirich Departement Mathematik Riimistr. 101 8092 Ziirich Switzerland Weierstrass Institute for Applied Analysis and Stochastics Mohrenstr. 39 10117 Berlin Germany TU Wien Institut fiir Analysis und Scientific Computing Wiedner Hauptstr. 8-10//1011040 Wien Austria

Nearly all inf-sup stable mixed finite elements for the incompressible Stokes equations relax the divergence constraint. The price to pay is that a priori estimates for the ve- locity error become pressure-dependent, while divergence-free mixed finite elements de- liver pressure-independent estimates. A recently introduced new variational crime using lowest-order Raviart-Thomas velocity reconstructions delivers a much more robust modi- fied crouzeix-Raviart element, obeying an optimal pressure-independent discrete h1 ve- locity estimate. Refining this approach, a more sophisticated variational crime employing the lowest-order BDM element is proposed, which also allows proving an optimal pressure- independent L2 velocity error. Numerical examples confirm the analysis and demonstrate the improved robustness in the Navier-Stokes case.

关键词： Variational crime crouzeix-Raviart finite element Divergence-free mixed me-thod Incompressible Navier-Stokes equations A priori error estimates.

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Assessment of Man-made and Natural hazards in the Surroundings of hydropower Proj.cts under construction in the Beas Valley of Northwestern himalaya

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j.urnal of Mountain Science 2007年第3期4卷 221-236页

作者： Sanj.ev Sharma j.gdish c. Kuniyal j. c. Sharma G.B. Pant Institute of himalayan Environment & Development Himachal UnitMohal-Kullu 175 126Himachal Pradesh India Department of Geography Himachal Pradesh University

Mountain ecosystem, on the earth, has plenty of natural resources. In himachal Pradesh all the rivers are snowfed and therefore rich in water resources. These resources have been supporting enough for the generation of electricity through introducing hydropower proj.cts since the last decade however, every developmental activity has its own negative impacts on the surrounding environment. Due to the fragile nature of topography and delicacy of ecology of the himalaya, it results in lot of disturbances because of high degree of human interferences like construction of maj.r hydropower proj.cts. The increased extent of geological hazards, such as landslides, rock fall and soil erosion, have mainly due to alike developmental interventions in the natural ecosystem. So understanding and analysing such impacts of the hydropower proj.cts have mainly been on the environment in various forms but natural hazards have been frequent ones. The present study, therefore, focuses mainly on the Parbati Stage II （800 MW） and the Parbati Stage III （520 MW） hydropower proj.cts; both of which fall within the Kullu district of himachal Pradesh. Based on the perception survey of the local communities, the existing land use pattern, status of total acquired land of the residents by hydropower proj.cts, frequent natural hazards and resultant loss to the local communities due to upcoming construction of hydropower proj.cts surrounding to the Parbati Stage II and III have been analysed in the paper. Also, the preventive measures to mitigate these adverse impacts have been suggested to strengthen these proj.cts in eco-friendly manner in the mountain context.

关键词： hydropower proj.ct under construction local community hazard preventive measure environment northwestern Indian himalaya

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hybrid finite-discrete element modelling of asperity degradation and gouge grinding during direct shearing of rough rock j.ints

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International j.urnal of coal Science & Technology 2016年第3期3卷 295-310页

作者： h. Y. Liu haoyu han h. M. An j. j. Shi School of Engineering and IcT University of TasmaniaHobart TAS 7001 Australia School of civil & Environmental Engineering University ofScience and Technology Beijing Beijing China

A hybrid finite-discrete element method was implemented to study the fracture process of rough rock j.ints under direct shearing. The hybrid method reproduced the j.int shear resistance evolution process from asperity sliding to degradation and from gouge formation to grinding. It is found that, in the direct shear test of rough rock j.ints under constant normal displacement loading conditions, higher shearing rate promotes the asperity degradation but constraints the volume dilation, which then results in higher peak shear resistance, more gouge formation and grinding, and smoother new j.int surfaces. Moreover, it is found that the j.int roughness affects the j.int shear resistance evolution through influencing the j.int fracture micro mechanism. The asperity degradation and gouge grinding are the main failure micro-mechanism in shearing rougher rock j.ints with deeper asperities while the asperity sliding is the main failure micro-mechanism in shearing smoother rock j.ints with shallower asperities. It is concluded that the hybrid finite-discrete element method is a valuable numerical tool better than traditional finite element method and discrete element method for modelling the j.int sliding, asperity degradation, gouge formation, and gouge grinding occurred in the direct shear tests of rough rock j.ints.

关键词： hybrid FEM-DEM Rock j.int Asperity sliding Asperity shearing Fragment grinding

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Neuroprotection by resveratrol-glucuronide and quercetin-glucuronide via binding to polyphenol-and glycosaminoglycan-binding sites in the laminin receptor

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Neural Regeneration Research 2025年第3期20卷 819-820页

作者： Rayudu Gopalakrishna j.nnifer Aguilar Emily Lee William j.Mack Department of Integrative Anatomical Sciences Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCAUSA Department of Neurological Surgery Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCAUSA

The dietary polyphenolic compounds resveratrol and quercetin prevent neurodegenerative diseases in experimental models;however, they reach the brain only in nanomolar concentrations in the glucuronidated and sulfated ... 详细信息

关键词： resveratrol molar dated

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