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mantle plume:the dynamic setting of the origin of Early Paleozoic mafic dykes in Ziyang,Shaanxi Province,Southern Qinling Block,China

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Acta Geochimica 2020年第3期39卷 307-325页

作者： Xiaoqing Chen Shen Liu Caixia Feng ian m.Coulson Yan Fan Kairui Tai Tianjing Gao Siyuan Zhang College of Earth Science Jilin UniversityChangchun 130061China State Key Laboratory of Continental Dynamics and Department of Geology Northwest UniversityXi'an 710069China Solid Earth Studies Laboratory Department of GeologyUniversity of ReginaReginaSK S4S 0A2Canada

The mafic dykes(dolerites)during the Early Paleozoic are widely spread in Langao-Ziyang,southern Qiling Block,and the investigation on these dykes are very *** studies have mainly focused on the Silurian mafic dykes;however,research on the Earlier Paleozoic mafic dykes is relatively weak at ***,the overall understanding of the mantle source and genetic dynamic setting during the Early Paleozoic in this area is *** study the accurate age and origin of the Early Paleozoic mafic dykes in Ziyang,southern Shaanxi Province,the mafic dykes from dabacunand Qinmingzhai were selected and the petrology,zircon U-Pb chronology,geochemistry,and Sr-Nd-Hf isotopes were *** indicates that the mafic dykes studied are mainly composed of dolerite,and they are the products of the Early Ordovician(475.8-480.7 ma).Furthermore,the dolerites belong to alkaline rock series,and they are characterized by enrichment in LREE,Rb,Ba,Sr,Nb,(87Sr/86Sr)i=0.7020-0.7050,εNd(t)=3.0-4.0),εHf(t)=4.5-12.1,176Hf/177Hf=*** suggests that the mafic dyke were derived from the partial melting of a depleted lithospheric mantle,and the genetic process is mainly controlled by the mantle plume based on the discussion of the genetic ***,the genetic process experienced the separation and crystallization of olivine and clinopyroxene at the same time,with little crustal contamination.

关键词： Early Paleozoic Dolerites Geochemistry Origin mantle plume

The commutant and similarity invariant of analytic Toeplitz operators on Bergman space

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Science China mathematics 2007年第5期50卷 651-664页

作者： Chun-ian JianG Yu-cheng Li Department of mathematics Hebei Normal UniversityShijiazhuang 050016China

The famous von Neumann-Wold Theorem tells us that each analytic Toeplitz operator with n + 1-Blaschke factors is unitary to n + 1 copies of the unilateral shift on the Hardy space. It is obvious that the von Neumann-Wold Theorem does not hold in the Bergman space. In this paper, using the basis constructed by michael and Zhu on the Bergman space we prove that each analytic Toeplitz operator m B(z) is similar to n + 1 copies of the Bergman shift if and only if B(z) is an n + 1-Blaschke product. From the above theorem, we characterize the similarity invariant of some analytic Toeplitz operators by using K 0-group term.

关键词： Bergman space analytic Toeplitz operators invariant subspace commutant similarity invariant K 0-group 32A36 46J40 47A15

Stable isotope analysis of diet confirms niche separation of two sympatric species of Namib Desert lizard

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Integrative Zoology 2016年第1期11卷 60-75页

作者： ian W.mURRAY Hilary m.LEASE Robyn S.HETEm Duncan mITCHELL Andrea FULLER Stephan WOODBORNE Brain Function Research Group School of PhysiologyFaculty of Health SciencesUniversity of the WitwatersrandJohannesburgSouth Africa Biology Department Whitman CollegeWalla WallaWashingtonUSA iThemba Laboratories GautengSouth Africa Stable Isotope Laboratory Mammal Research InstituteDepartment of Zoology and EntomologyUniversity of PretoriaPretoriaSouth Africa

We used stable isotopes of carbon and nitrogen to study the trophic niche of two species of insectivorous lizards,the Husab sand lizard Pedioplanis husabensis and Bradfield’s Namib day gecko living sympatrically in the Namib *** measured theδ13C andδ15N ratios in lizard blood tissues with different turnover times(whole blood,red blood cells and plasma)to investigate lizard diet in different *** also measured theδ13C andδ15N ratios in available arthropod prey and plant tissues on the site,to identify the avenues of nutrient movement between lizards and their *** the use of stable isotope mixing models,we found that the two lizard species relied on a largely non-overlapping but seasonally variable array of arthropods:*** primarily fed on termites,beetles and wasps,while *** fed mainly on ants,wasps and *** originating from C3 plants were proportionally higher for *** than for *** during autumn and late autumn/early winter,although not *** to the few available data estimating the trophic transfer of nutrients in ectotherms in mixed C3 and C4/crassulacean acid metabolism(CAm)plant landscapes,we found that our lizard species primarily acquired nutrients that originated from C4/CAm *** work adds an important dimension to the general lack of studies using stable isotope analyses to estimate lizard niche partitioning and resource use.

关键词： Namib Desert niche partitioning Pedioplanis Rhoptropus stable isotopes

Downscaling Landsat-8 land surface temperature maps in diverse urban landscapes using multivariate adaptive regression splines and very high resolution auxiliary data

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International Journal of Digital Earth 2020年第8期13卷 899-914页

作者： Joanna Zawadzka Ron Corstanje Jim Harris ian Truckell Centre for Environmental and Agricultural Informatics School of WaterEnergy and EnvironmentCranfield UniversityBedfordshireUK

We propose a method for spatial downscaling of Landsat 8-derived LST maps from 100(30 m)resolution down to 2–4 m with the use of the multiple Adaptive Regression Splines(mARS)models coupled with very high resolution auxiliary data derived from hyperspectral aerial imagery and large-scale topographic *** applied the method to four Landsat 8 scenes,two collected in summer and two in winter,for three British towns collectively representing a variety of urban *** used several spectral indices as well as fractional coverage of water and paved surfaces as LST predictors,and applied a novel method for the correction of temporal mismatch between spectral indices derived from aerial and satellite imagery captured at different dates,allowing for the application of the downscaling method for multiple dates without the need for repeating the aerial *** results suggest that the method performed well for the summer dates,achieving RmSE of 1.40–1.83 K prior to and 0.76–1.21 K after correction for *** conclude that the mARS models,by addressing the non-linear relationship of LST at coarse and fine spatial resolutions,can be successfully applied to produce high resolution LST maps suitable for studies of urban thermal environment at local scales.

关键词： Land surface temperature downscaling urban multivariate adaptive regression splines remote sensing

Confidence estimation in the prediction of epithermal neutron resonance self-shielding factors in irradiation samples using an ensemble neural network

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能源与人工智能(英文) 2022年第1期7卷 101-119页

作者： ian m.Wilkinson Ritwik R.Bhattacharjee Jenifer C.Shafer Andrew G.Osborne Nuclear Science&Engineering The Colorado School of Mines101214th St.GoldenCO80401USA Department of Chemistry The Colorado School of Mines101214th St.GoldenCO80401USA Department of mechanical Engineering The Colorado School of Mines1610 Illinois St.GoldenCO80401USA

Large neutron absorption resonances in the nuclides present in irradiation samples reduce the irradiating neutron flux at energies close to a *** neutron activation analysis of optically thick samples with resonant isotopes,this self-shielding effect can be significant,and must be accounted for to ensure accurate *** we show that an ensemble artificial neural network can be used to accurately predict the epithermal selfshielding factors in wires composed of up to 57 ***,the neural network can account for resonance interference that affects the self-shielding in samples containing nuclides with large overlapping *** use monte Carlo simulations of sample wires irradiated in a thermal neutron spectrum to create the data for training the neural network and validate its predictions.A Gaussian negative log likelihood loss function is combined with the ensemble to estimate the confidence in the predicted self-shielding factors when ground-truth data are unavailable.

关键词： Neutron activation analysis Epithermal self-shielding Neural Networks

The role of functional materials to produce high areal capacity lithium sulfur battery

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Journal of Energy Chemistry 2020年第3期29卷 195-209页

作者： masud Rana Bin Luo mohammad Rejaul Kaiser ian Gentle Ruth Knibbe materials Engineering School of Mechanical and Mining EngineeringUniversity of QueenslandSt LuciaQLD 4072Australia Nanomaterials Centre School of Chemical Engineering and Australian Institute for Bioengineering and NanotechnologyThe University of Queensland QLDSt Lucia 4072Australia School of Chemistry and molecular Biosciences Faculty of ScienceThe University of QueenslandSt LuciaQLD 4072Australia Commonwealth Scientific and Industrial Research Organization(CSIRO) Manufacturing Business Unit36 Bradfield RoadLindfieldNSW 2070Australia

The lithium sulfur batteries(LSBs) are considered as one of the promising next generation energy storage devices due to the high theoretical specific capacity of sulfur(1675 m Ah g-1), naturally available, low ***, the practical LSBs are impeded by the well-known "shuttle effect" combined with other technical drawbacks. The "shuttle effect" causes rapid capacity decay, severe self-discharging and low active material utilization. The polysulfide(PS) which has lone pair electrons in each sulfur atom is considered as Lewis base and shows strong affinity to various polar, Lewis acid and catenation interactive materials but very weakly interacts with the non-polar conductive carbons. The "shuttle effect" occurs due to the diffusion of high order PS from the cathode to the anode and then low-order PS back to the cathode. The PS is polar and, due to a lone pair of electrons associated with the sulfur atom, is considered a Lewis base. As such, the PS shows a strong affinity with various polar and Lewis acid materials. In addition, a more novel trapping can be performance through a catenation reaction. For LSBs to compete with the state-of-the-art lithium ion batteries(LIBs), the LSB areal capacity need to be ~6 m Ah cm-2(which is proportional to sulfur loading). To achieve this target the PS shuttling needs to mitigate, which can be achieved through using functional materials. This review addresses the aforementioned phenomena by considering the PS phase interacts with the various functional materials and how this impacts areal capacity and cycling stability of LSBs.

关键词： Sulfur loading Specific capacity Areal capacity Polysulfides Chemical interaction

Characterisation of Neonicotinoid and Pymetrozine Resistance in Strains of Bemisia tabaci(Hemiptera:Aleyrodidae)from China

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Journal of Integrative Agriculture 2012年第2期11卷 321-326页

作者： RAO Qiong XU Yong-hua LUO Chen ZHANG Hong-yu Christopher m Jones Greg J Devine KevinGorman ian Denholm College of Plant Science and Technology Huazhong Agricultural University Wuhan 430070 P.R.China Institute of Plant and Environmental Protection Beijing Academy of Agriculture ＆ Forestry Sciences Beijing 100097 P.R.China Plant and Invertebrate Ecology Department Rothamsted Research Harpenden Herts .4L5 2JQ United Kingdom Zhejiang Chemical Industry Research Institute Zhejiang Branch of National Pesticide R＆D South Center Hangzhou 310023 P.R. China

Four strains of the Q biotype and one of the B biotype of the whitefly Bemisia tabaci collected from China were characterised for resistance to four neonicotinoid insecticides and pymetrozine.Q biotype strains showed moderate to strong resistance to imidacloprid,thiamethoxam and acetamiprid,but little or no cross-resistance to *** to neonicotinoids was consistently associated with resistance to pymetrozine,despite the latter having a distinct（though unresolved）mode of *** single B biotype strain proved largely susceptible to all the insecticides *** in the Q biotype strains was associated with over-expression of a cytochrome P450 monooxygenase gene,CYP6Cm1,whose substrate specificity presumably accounts for the observed cross-resistance profiles.

关键词： P450 cross-resistance pymetrozine imidacloprid thiamethoxam acetamiprid dinotefuran neonicotinoids

Feature identification in complex fluid flows by convolutional neural networks

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Theoretical & Applied mechanics Letters 2023年第6期13卷 447-454页

作者： Shizheng Wen michael W.Lee Kai m.Kruger Bastos ian K.Eldridge-Allegra Earl H.Dowell Department of mathematics ETH ZurichZürich 8092Switzerland NASA Langley Research Center HamptonVA 23666USA Rivian San FranciscoCA 94080USA Department of mechanical Engineering and materials Science Duke UniversityDurhamNC 27708USA

Recent advancements have established machine learning's utility in predicting nonlinear fluid dynamics,with predictive accuracy being a central motivation for employing neural ***,the pattern recognition central to the networks function is equally valuable for enhancing our dynamical insight into the complex fluid *** this paper,a single-layer convolutional neural network(CNN)was trained to recognize three qualitatively different subsonic buffet flows(periodic,quasi-periodic and chaotic)over a high-incidence airfoil,and a near-perfect accuracy was obtained with only a small training *** convolutional kernels and corresponding feature maps,developed by the model with no temporal information provided,identified large-scale coherent structures in agreement with those known to be associated with buffet *** to hyperparameters including network architecture and convolutional kernel size was also *** coherent structures identified by these models enhance our dynamical understanding of subsonic buffet over high-incidence airfoils over a wide range of Reynolds numbers.

关键词： Subsonic buffet flows Feature identification Convolutional neural network Long-short term memory

Zircon U-Pb Age,Geochemical,and Sr-Nd-Pb-Hf Isotopic Constraints on the Time Frame and Origin of Early Cretaceous mafic Dykes in the Wuling mountain Gravity Lineament,South China

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Acta Geologica Sinica(English Edition) 2021年第2期95卷 419-438页

作者： CHEN Xiaoqing LIU Shen FENG Caixia XU Jingyan ZHAO Huibo FENG Guangying ian m.COULSON SUN Jinggui FAN Yan College of Earth Sciences Jilin UniversityChangchun 130061China State Key Laboratory of Continental Dynamics and Department of Geology Northwest UniversityXi'an 710069China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China Solid Earth Studies Laboratory Department of GeologyUniversity of ReginaReginaSaskatchewan S4S 0A2Canada

In view of the importance of mafic dyke swarms and their contribution to current scientific problems relating to South China,herein,we present the findings of studies on twenty–five representative mafic dykes cropping out in Hunan Province and Guangxi Zhuang Autonomous Region,within the southern Wuling mountain gravity lineament,*** results include new zircon LA-ICP-mS U-Pb age,whole rock geochemical,Sr-Nd-Pb isotopic,and zircon Hf isotopic data for these *** dykes formed between 131.5±1.2 and 121.6±1.1 ma,and have typical doleritic *** fall into the alkaline and shoshonitic series,are enriched in light rare earth elements(LREE),some large ion lithophile elements(LILE;e.g.,Rb,Ba,and Sr),Th,U,and Pb,and are depleted in Nb,Ta,Hf,and ***,the dolerites have high initial 87 Sr/86 Sr ratios(0.7055–0.7057),negativeεNd(t)and zirconεHf(t)values(-14.8 to-11.9,-30.4 to-14.9),and relatively constant initial Pb isotopic ratios(that are Em1-like,16.77–16.94,15.43–15.47,and 36.84–36.92 for 206 Pb/204 Pb,207 Pb/204 Pb,and 208 Pb/204 Pb,respectively).These results indicate that the dykes were likely derived from magma generated through low-degree partial melting(1.0%–10%)of an Em1-like garnet–lherzolite mantle *** parental magmas fractionated olivine,clinopyroxene,plagioclase,and Ti-bearing phases with negligible crustal contamination,during ascent and dyke *** possible models have been proposed to explain the origin of mesozoic magmatism along the Wuling mountain gravity *** we propose a reasonable model for the origin of these mafic dykes,involving the collision between the paleo-Pacific Plate and South China,which led to subsequent lithospheric extension and asthenosphere upwelling,resulting in partial melting the underlying mantle lithosphere in the Early Cretaceous,to form the parental magmas to the WmGL mafic dykes,as studied.

关键词： mafic dykes magmatic origin Early Cretaceous Wuling mountain gravity lineament South China