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Petrology,geochemistry and source characteristics of the Burpala alkaline massif,north Baikal

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Geoscience Frontiers 2017年第4期8卷 711-719页

作者： n.v.vladykin I.A.Sotnikova vinogradov Institute of Geochemistry Siberian BranchRussian Academy of Sciences

The Burpala alkaline massif contains rocks with more than 50 minerals rich in Zr,nb,Ti,Th,Be and rare earth elements（REE）.The rocks vary in composition from shonkinite,melanocratic syenite,nepheline and alkali syenites to alaskite and alkali granite and contain up to 10%LILE and HSFE,3.6%of REE and varying amounts of other trace elements（4%Zr,0.5%Y,0.5%nb,0.5%Th and 0.1%U）.Geological and geochemical data suggest that all the rocks in the Burpala massif were derived from alkaline magma enriched in rare earth *** extreme products of magma fractionation are REE rich pegmatites,apatite-fiuorite bearing rocks and *** Sr and nd isotope data suggest that the source of primary melt is enriched mantle（em-Ⅱ）.We correlate the massif to mantle plume impact on the active margin of the Siberian continent.

关键词： Syenite Pegmatite Rare metal and rare earths Petrology Geochemistry

When to pull the trigger in nonazoospermic infertile men undergoing intracytoplasmic sperm injection?

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Asian Journal of Andrology 2020年第4期22卷 439-440页

作者： Sandro C Esteves Sheena em Lewis AnDROFERT Andrology and Human Reproduction ClinicReferral Center for Male Reproduction13075-460 CampinasSPBrazil Department of Surgery(Division of Urology) University of Campinas(UNICAMP)13083-887 CampinasSPBrazil Faculty of Health Aarhus University8000 AarhusDenmark Queens University Belfast Northern Ireland BT71NNUK Examenlab Ltd. Weavers Court Business ParkLinfield RoadBelfastNorthern Ireland BT125GHUK

Before the era of intracytoplasmic sperm injection(ICSI),few options were available for men with severe infertility to father a biological *** in 1992 as a modification of conventional in vitro fertilization,ICSI has enabled men with low sperm quantity and quality to have their own biological offspring.[1]Among nonazoospermic infertile men,ICSI has been traditionally carried out with ejaculated *** contrast,methods to harvest sperm from the epididymides and testes are used for ICSI in men with azoospermia-related infertility.

关键词： injection infertility traditionally

Physics-informed neural networks(PInns)for fluidmechanics:a review

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Acta Mechanica Sinica 2021年第12期37卷 1727-1738页

作者： Shengze Cai Zhiping Mao Zhicheng Wang Minglang Yin George em Karniadakis Division of Applied Mathematics Brown UniversityProvidenceRI 02912USA School of Mathematical Sciences Xiamen University 361005 China Laboratory of Ocean Energy Utilization of Ministry of Education Dalian University of TechnologyDalian116024China School of Engineering Brown UniversityProvidenceRI 02912USA Center for Biomedical Engineering Brown UniversityProvidenceRI 02912USA

Despite the significant progress over the last 50 years in simulating flow problems using numerical discretization of the navier–Stokes equations(nSE),we still cannot incorporate seamlessly noisy data into existing algorithms,mesh-generation is complex,and we cannot tackle high-dimensional problems governed by parametrized ***,solving inverse flow problems is often prohibitively expensive and requires complex and expensive formulations and new computer ***,we review flow physics-informed learning,integrating seamlessly data and mathematical models,and implement them using physics-informed neural networks(PInns).We demonstrate the effectiveness of PInns for inverse problems related to three-dimensional wake flows,supersonic flows,and biomedical flows.

关键词： Physics-informed learning PInns Inverse problems Supersonic flows Biomedical flows

Error Control in Multi-Element Generalized Polynomial Chaos Method for Elliptic Problems with Random Coefficients

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Communications in Computational Physics 2009年第2期5卷 793-820页

作者： Xiaoliang Wan George em Karniadakis Division of Applied Mathematics Brown UniversityProvidenceRI 02912USA

We develop the theory for a robust and efficient adaptive multi-element generalized polynomial chaos(ME-gPC)method for elliptic equations with random coefficients for a moderate number(O(10))of random *** employ loworder(p≤3)polynomial chaos and refine the solution using adaptivity in the parametric *** first study the approximation error of ME-gPC and prove its *** subsequently generate local and global a posteriori error *** order to resolve the error equations efficiently,we construct a reduced space using much smaller number of terms in the enhanced polynomial chaos space to capture the errors of ME-gPC *** on the a posteriori estimators,we propose and implement an adaptive ME-gPC algorithm for elliptic problems with random *** results for convergence and efficiency are also presented.

关键词： Stochastic PDE a posteriori error estimate elliptic problems adaptive numerical methods uncertainty quantification

Population viability analysis: using a modeling tool to assess the viability of tapir populations in fragmented landscapes

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Integrative Zoology 2012年第4期7卷 356-372页

作者： emília Patrícia MEDICI Arnaud Leonard Jean DESBIEZ Lowland Tapir Conservation Initiative IPÊ-Institute for Ecological ResearchNazaréPaulistaSão PauloBrazil IUCn/SSC Tapir Specialist Group(TSG) GlandSwitzerland Escola Superior de Conservação Ambiental e Sustentabilidade(ESCAS/IPÊ) NazaréPaulistaSão PauloBrazil IUCn/SSC Conservation Breeding Specialist Group(CBSG) Brazil NetworkCampo GrandeMSBrazil Royal Zoological Society of Scotland EdinburghScotland

A population viability analysis(PvA)was conducted of the lowland tapir populations in the Atlantic Forest of the Pontal do Paranapanema region,Brazil,including Morro do Diabo State Park(MDSP)and surrounding forest *** from the model projected that the population of 126 tapirs in MDSP is likely to per-sist over the next 100 years;however,200 tapirs would be required to maintain a viable ***-ity analysis showed that sub-adult mortality and adult mortality have the strongest influence on the dynamics of lowland tapir *** road-kill has a major impact on the MDSP tapir population and can lead to population *** modeling showed that dispersal of tapirs from MDSP to the surrounding fragments can be detrimental to the overall metapopulation,as fragments act as ***,the model showed that under certain conditions the maintenance of the metapopulation dynamics might be determinant for the persistence of tapirs in the region,particularly in the smaller *** establishment of corridors con-necting MDSP to the forest fragments models resulted in an increase in the stochastic growth rate,making ta-pirs more resilient to threats and catastrophes,but only if rates of mortality were not increased when using *** PvA showed that the conservation of tapirs in the Pontal region depends on:the effective protection of MDSP;maintenance and,whenever possible,enhancement of the functional connectivity of the landscape,reducing mortality during dispersal and threats in the unprotected forest fragments;and neutralization of all threats affecting tapirs in the smaller forest fragments.

关键词： Atlantic Forest fragmentation lowland tapir minimum viable population population viability analysis

Analytical and Computational Studies of Correlations of Hydrodynamic Fluctuations in Shear Flow

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Communications in Computational Physics 2018年第1期23卷 93-117页

作者： Xin Bian Mingge Deng George em Karniadakis Division of Applied Mathematics Brown UniversityProvidenceRhode Island 02912USA Lehrstuhl fur Aerodynamik und Stromungsmechanik Technische Universitat Munchen85748 GarchingGermany

We study correlations of hydrodynamic fluctuations in shear flow analytically and also by dissipative particle dynamics(DPD)*** hydrodynamic equations are linearized around the macroscopic velocity field and then solved by a perturbation method in Fourier-transformed *** autocorrelation functions(ACFs)fromthe analyticalmethod are comparedwith results obtained fromDPD simulations under the same shear-flow *** to a moderate shear rate,various ACFs from the two approaches agree with each other *** large shear rates,discrepancies between the two methods are observed,hence revealing strong additional coupling between different fluctuating variables,which is not considered in the analytical *** addition,the results at low and moderate shear rates can serve as benchmarks for developing multiscale algorithms for coupling of heterogeneous solvers,such as a hybrid simulation of molecular dynamics and fluctuating hydrodynamics solver,where thermal fluctuations are indispensable.

关键词： Hydrodynamic fluctuations correlation functions dissipative particle dynamics shear flow

nonlocal Flocking Dynamics: Learning the Fractional Order of PDEs from Particle Simulations

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Communications on Applied Mathematics and Computation 2019年第4期1卷 597-619页

作者： Zhiping Mao Zhen Li George em Karniadakis Division of Applied Mathematics Brown UniversityProvidenceRI02912USA Pacific northwest national Laboratory RichlandWA 99354USA

Flocking refers to collective behavior of a large number of interacting entities,where the interactions between discrete individuals produce collective motion on the large *** employ an agent-based model to describe the microscopic dynamics of each individual in a flock,and use a fractional partial differential equation(fPDE)to model the evolution of macroscopic quantities of *** macroscopic models with phenomenological interaction functions are derived by applying the continuum hypothesis to the microscopic *** of specifying the fPDEs with an ad hoc fractional order for nonlocal flocking dynamics,we learn the effective nonlocal influence function in fPDEs directly from particle trajectories generated by the agent-based *** demonstrate how the learning framework is used to connect the discrete agent-based model to the continuum fPDEs in one-and two-dimensional nonlocal flocking *** particular,a Cucker-Smale particle model is employed to describe the microscale dynamics of each individual,while Euler equations with nonlocal interaction terms are used to compute the evolution of macroscale *** trajectories generated by the particle simulations mimic the field data of tracking logs that can be obtained *** can be used to learn the fractional order of the influence function using a Gaussian process regression model implemented with the Bayesian *** show in one-and two-dimensional benchmarks that the numerical solution of the learned Euler equations solved by the finite volume scheme can yield correct density distributions consistent with the collective behavior of the agent-based system solved by the particle *** proposed method offers new insights into how to scale the discrete agent-based models to the continuum-based PDE models,and could serve as a paradigm on extracting effective governing equations for nonlocal flocking dynamics directly from particle trajectories.

关键词： Fractional PDEs Gaussian process Bayesian optimization Fractional Laplacian Conservation laws

The evaluation of gastrointestinal function in diabetic patients

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World Journal of Gastroenterology 1999年第4期5卷 5-10页

作者： Quigley em

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关键词： gastrointestinal diabetic evaluation function The

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水铁矿对土壤溶解性有机质的吸附固持作用

农业环境科学学报 2024年第3期43卷 627-635页

作者：麦富生李晓雯吕睿沈倩杨健赵好轩 vAHATALO Anssi v. 肖宜华青岛理工大学环境与市政工程学院山东青岛266000

基于水解法将氯化铁和氢氧化钠合成了一种水铁矿,通过不同浓度水铁矿与土壤溶解性有机质(DOM)的混合避光培养实验,研究了水铁矿对土壤DOM的吸附固持作用。结果表明:在水铁矿浓度为10~30 g·L^(-1)范围内,水铁矿对土壤DOM的吸附能力与其... 详细信息

基于水解法将氯化铁和氢氧化钠合成了一种水铁矿,通过不同浓度水铁矿与土壤溶解性有机质(DOM)的混合避光培养实验,研究了水铁矿对土壤DOM的吸附固持作用。结果表明:在水铁矿浓度为10~30 g·L^(-1)范围内,水铁矿对土壤DOM的吸附能力与其浓度呈正相关。随着培养时间的延长,DOM的光谱斜率(S_(275-295))显著降低,表明水铁矿优先吸附土壤DOM中的大分子芳香族化合物。三维荧光光谱耦合平行因子模型(Eem-PARAFAC)分析表明,土壤DOM包含类腐殖质组分(C1)(Ex/em=240/410)、类色氨酸组分(C2)[Ex/em=290(240)/350]及类酪氨酸组分(C3)(Ex/em=270/300)3种荧光组分。3种组分荧光强度均随着培养时间延长呈现明显降低趋势,且类腐殖质组分的下降最为明显。被水铁矿吸附后,土壤DOM的腐殖化指数(HIX)显著降低且生物源指数(BIX)明显升高,表明随着吸附作用的进行,土壤DOM的腐殖质组分相对占比下降,而自生源组分相对占比上升。研究表明,水铁矿对土壤DOM有显著的吸附固持作用,且对大分子腐殖质物质吸附作用强于对小分子类蛋白组分,水铁矿对土壤DOM分子的固持作用能够提高土壤有机质的生物可利用度,改善土壤环境。

关键词：水铁矿溶解性有机质土壤紫外-可见吸收光谱平行因子分析