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A Wavelet-Free Approach for Multiresolution-Based Grid Adaptation for Conservation Laws

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Communications on Applied Mathematics and Computation 2022年第1期4卷 108-142页

作者： nils Gerhard Siegfried Müller Aleksey Sikstel Institut für Geometrie und Praktische Mathematik RWTH AachenTemplergraben 55Aachen 52056Germany

In recent years the concept of multiresolution-based adaptive discontinuous Galerkin(DG)schemes for hyperbolic conservation laws has been *** key idea is to perform a multiresolution analysis of the DG solution using multiwavelets defined on a hierarchy of nested *** this concept is applied to dyadic grid hierarchies where the explicit construction of the multiwavelets has to be performed only for one reference *** non-uniform grid hierarchies multiwavelets have to be constructed for each element and,thus,becomes extremely *** overcome this problem a multiresolution analysis is developed that avoids the explicit construction of multiwavelets.

关键词： Discontinuous Galerkin Grid adaptivity Multiwavelets Multiresolution analysis Conservation laws

First steps in reconstructing Early Jurassic sea water temperatures in the Andean Basin of northern Chile based on stable isotope analyses of oyster and brachiopod shells

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Journal of Palaeogeography 2020年第1期9卷 71-87页

作者： Matthias Alberti Franz T.Fürsich nils Andersen Institut für Geowissenschaften Christian-Albrechts-Universitat zu KielLudewig-Meyn-Straβe 1024118 KielGermany GeoZentrum Nordbayern Fachgruppe PalaoUmweltFriedrich-Alexander-Universitat Erlangen-NürnbergLoewenichstraβe 2891054 ErlangenGermany Leibniz Laboratory for Radiometric Dating and Stable Isotope Research Christian-Albrechts-Universitat zu KielMax-Eyth-Straβe 1124118 KielGermany

The stable isotope(δ13 C,δ18 O)composition of a collection of Lower Jurassic brachiopods and oysters from the Andean Basin of northern Chile was *** results allow the first reconstruction of absolute water temperatures for several ammonite zones in the Lower Jurassic of South *** temperature record starts with comparatively high values in the Late Sinemurian(average:27.0℃;Raricostatum Zone).Just before the Sinemurian–Pliensbachian transition,temperatures dropped to an average of 24.3℃.The lowest temperature value in the dataset was recorded for a brachiopod shell of the latest Pliensbachian Spinatum Zone(19.6℃).No data are available for the Early Toarcian,but results for the late Toarcian show again comparatively warm conditions(average:24.4℃;Thouarsense–Levesquei zones).Even though more material and analyses are necessary to corroborate the recorded temperatures,the present dataset seems to indicate the global nature of the Late Pliensbachian Cooling *** contrast,the global warming during the Toarcian Oceanic Anoxic Event has not been recorded due to a lack of Early Toarcian ***δ13 C record of brachiopods and oysters documents a gradual increase in values representing background *** shells were used for high-resolution stable isotope analyses and show seasonal temperature fluctuations over a period of around 3 years in the life time of the *** explained only by temperatures,theδ18 O values point to a minimum estimate for the seasonality in the late Toarcian of slightly more than 3℃.

关键词： Early Jurassic Chile Stable isotopes Palaeoclimate Water temperatures Seasonality

Why 2022 is a revolutionary year for potato genomics

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Molecular Plant 2022年第8期15卷 1257-1259页

作者： M.Timothy Rabanus-Wallace nils Stein Leibniz Institute of Plant Genetics and Crop Plant Research(IPK) Stadt SeelandGermany Center for Integrated Breeding Research Georg-August-University Gottingen37075 GottingenGermany

While the humble spud may seem simple enough boiled on a plate,a lot of thought and effort goes into producing the varieties we like to *** lovers are conservative:the Russet Burbank,for instance,has produced our favorite French fries since 1902(Bethke et al.,2014).Cultivars need to be genetically stable-a state that is achieved in self-pollinating crop species like wheat and barley by repeated inbreeding.

关键词： favorite varieties instance

Simulation for MSS-2 low-perigee elliptical orbit satellites:an example of lithospheric magnetic field modelling

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Earth and Planetary Physics 2023年第1期7卷 151-160页

作者： Yi Jiang nils Olsen JiaMing Ou Qing Yan State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyTaipa 999078MacaoChina Division of Geomagnetism DTU SpaceNational Space InstituteTechnical University of DenmarkDiplomvej 3712800 Kgs.LyngbyDenmark

A future constellation of at least four geomagnetic satellites(designated Macao Scientific Satellite-1(MSS-1)and Macao Scientific Satellite-2(MSS-2))was recently proposed,to continue high-quality geomagnetic observations in the post-Swarm period,focusing especially on collecting data that will provide a global,three-dimensional survey of the geomagnetic *** this paper,we present a simulation of two years of orbits(2020.01.01-2022.01.01)of two satellites(tentatively denoted as MSS-2)that are constellated in elliptical(200×5,300 km)low-perigee *** comparing error variances of Gauss coefficients,we investigate the sensitivity of lithospheric magnetic field modelling to data collected from various satellite orbits,including a near circular reference orbit of 300×350km,and elliptical orbit of 180×5,300 km,220×5,300 km,200×3,000 km and 200×1,500 *** find that in two years the two MSS-2 satellites can collect 35,000 observations at altitude below 250 km,data that will be useful in advancing the quality of lithospheric magnetic field modelling;this number of observations reflects the fact that only 4.5%of the flight time of these satellites will be below250 km(just 6.4%of their flight time below 300 km).By combining observations from the MSS-2 satellites’elliptical orbits of 200×5,300km with observations from a circular reference orbit,the variance of the geomagnetic model can be reduced by a factor of 285 at spherical harmonic degree n=200 and by a factor of 1,300 at n=*** planned lower perigee of their orbits allows the new satellites to collect data at unprecedentedly lower altitudes,thus dramatically improving the spatial resolution of satellite-derived lithospheric field models,(up to 80%at n=150).In addition,lowering the apogee increases the time interval during which the satellites fly at near-Earth altitudes,thus improving the model predictions at all spherical harmonic degrees(around 52%-62%at n=150).The upper limit of the expected improvement to t

关键词： elliptical orbit satellite orbit simulation lithosphere field modelling spherical harmonics

Diagenetic mineralogy and its effect on the reservoir properties of the sandstones of the Permian of S120 block(Sulige gas field),Ordos Basin,NW China

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Journal of Palaeogeography 2022年第3期11卷 360-386页

作者： Qi Wan Ai-Ping Fan Ren-Chao Yang nils Lenhardt Shandong Provincial Key Laboratory of Depositional Mineralization&Sedimentary Minerals Shandong University of Science and TechnologyQingdao266590China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao266071China Department of Geology University of PretoriaPrivate Bag X200028PretoriaSouth Africa

The characteristics of diagenetic minerals and their effects on reservoir quality of the tight sandstones of the Permian in Sulige gas field of the Ordos Basin were studied through observations on thin sections,scanning electron microscopy,energy dispersive spectroscopy analysis and electron microprobe *** minerals in the Permian sandstones consist of illite,kaolinite,chlorite,siliceous and calcite *** amounts of intercrystalline pores between kaolinite and illite provide channels for acidic fluids flow and thereby were conducive to the formation of clastic solution pores,intergranular solution pores and composite *** chlorite occurs in the form of three morphotypes as grain-coating,pore-lining and ***-coating and pore-lining chlorite with different crystal shapes occur as coatings on the framework ***-filling chlorite precipitated as discrete flaky plates in pore *** microcrystals developed but quartz overgrowth did not develop because of the occurrence of porelining ***,in turn,led to the preservation of primary pores by occupying potential nucleation sites for quartz overgrowth and thereby preventing quartz microcrystals from merging into quartz *** process is regarded as the most important for influencing the quality of the lithophysical *** cement was mainly precipitated during a late diagenetic stage and has a negative effect on the reservoir *** study provides important insights into analyzing the relationship between diagenetic minerals and reservoir quality and the results are directly applicable to the exploration and development of tight sandstone reservoirs all over the world.

关键词： Ordos basin Sulige gas field Permian Diagenetic processes Siliceous cement Chlorite

Energy Dissipation Within the Wave Run-Up at Stepped Revetments

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Journal of Ocean University of China 2017年第4期16卷 649-654页

作者： KERPEN nils B BUNG Daniel B VALERO Darnel SCHLURMANN Torsten Ludwig-Franzius-lnstitute Leibniz Universitat Hannover30167 HannoverGermany Hydraulic Engineering Section Fachhochschule Aachen52066 AachenGermany

To understand the processes and energy dissipation performance caused by turbulence during the wave run-up over a stepped revetment,hydraulic model tests with steady flow conditions are conducted and correlated with unsteady flow conditions of the wave run-up within a short time *** irregular waves,the run-up reduction over a stepped revetment is dependent on the Iribarren number and decreases for decreasing Iribarren *** gradients are found to be similar in a steady and unsteady flow regime near the pseudo-bottom.

关键词： run-up stepped revetment roughness: energy dissipation

Time sensitive networking security:issues of precision time protocol and its implementation

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Cybersecurity 2023年第4期6卷 1-13页

作者： Davide Berardi nils OTippenhauer Andrea Melis Marco Prandini Franco Callegati Alma Mater Studiorum-Universitàdegli studi di Bologna BolognaItaly CISPA Helmholtz Center for Information Security SaarbrückenGermany

Time Sensitive Networking(TSN)will be an integral component of industrial *** synchronization in TSN is provided by the IEEE-1588,Precision Time Protocol(PTP)*** standard,dating back to 2008,marginally addresses security aspects,notably not encompassing the frames designed for management purposes(Type Length Values or TLVs).In this work we show that the TLVs can be abused by an attacker to reconfigure,manipulate,or shut down time *** effects of such an attack can be serious,ranging from interruption of operations to actual unintended behavior of industrial devices,possibly resulting in physical damages or even harm to *** paper analyzes the root causes of this vulnerability,and provides concrete examples of attacks leveraging it to de-synchronize the clocks,showing that they can succeed with limited resources,realistically available to a malicious actor.

关键词： Time synchronization Time sensitive networking Precision time protocol Cybersecurity attacks

Analyzing short time series data from periodically fluctuating rodent populations by thresholdmodels: A nearest block bootstrap approach

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Science China Mathematics 2009年第6期52卷 1085-1106页

作者： CHAN Kung-Sik TONG Howell STENSETH nils Chr Department of Statistics and Actuarial Science The University of IowaIowa CityIA 52242USA Department of Statistics London School of Economics & the University of Hong KongHong KongChina Centre for Ecological and Evolutionary Synthesis(CEES) Department of BiologyUniversity of OsloP.O.Box 1066 BlindernN-0316 OsloNorway

The study of the rodent fluctuations of the North was initiated in its modern form with Elton's pioneering *** scientific studies have been designed to collect yearly rodent abundance data,but the resulting time series are generally subject to at least two "problems":being short and *** explore the use of the continuous threshold autoregressive(TAR) models for analyzing such *** the simplest case,the continuous TAR models are additive autoregressive models,being piecewise linear in one lag,and linear in all other *** location of the slope change is called the threshold *** continuous TAR models for rodent abundance data can be derived from a general prey-predator model under some simplifying *** lag in which the threshold is located sheds important insights on the structure of the prey-predator *** propose to assess the uncertainty on the location of the threshold via a new bootstrap called the nearest block bootstrap(NBB) which combines the methods of moving block bootstrap and the nearest neighbor *** NBB assumes an underlying finite-order time-homogeneous Markov ***,the NBB bootstraps blocks of random block sizes,with each block being drawn from a non-parametric estimate of the future distribution given the realized past bootstrap *** illustrate the methods by simulations and on a particular rodent abundance time series from Kilpisjrvi,Northern Finland.

关键词： AIC continuous threshold autoregressive model non-nested hypotheses partial residual plots 62M10 62P10

Changes in culm surface temperature with maturity of the bamboo species Guadua angustifolia

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Journal of Forestry Research 2016年第2期27卷 419-425页

作者： nils Nolke Juan Carlos Camargo Garcia Christoph Klein Andrea Polle Chair of Forest Inventory and Remote Sensing Universitat GottingenBusgenweg 537077 GottingenGermany Faculty of Environmental Sciences Technological Universityof PereiraLa JulitaPereiraColombia Department of Forest Botany and Tree Physiology Universiat GottingenBiJsgenweg 237077 GottingenGermany

We used thermal images of bamboo culms of Guadua angustifolia Kunth to analyze the relationship between culm surface temperature and maturity, driven by the hypothesis that young culms may exhibit lower surface temperatures than old ones. The culm surface temperature shows small but constant differences between three age classes of 1, 2, and 3 years. Our findings indicate that surface temperature may be applied as an additional indi- cator to support the determination of maturity of guadua culms besides the visual assessment of the culms.

关键词： Bamboo culms Thermal images Bamboowood quality