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A POSTERIORI ENERGY-NORM ERROR ESTIMATES FOR ADVECTION-DIFFUSION EQUATIONS APPROXIMATED BY WEIGHTED INTERIOR PENALTY METHODS

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Journal of Computational Mathematics 2008年第4期26卷 488-510页

作者： Alexandre ern AnnetteF.Stephansen Université Paris-Est CermicsEcole des Ponts6 et 8 avenue Blaise PascalChamps sur Marne77455 Marne la Vallée Cedex 2France Université Paris-Est CermicsEcole des Ponts6 et 8 avenue Blaise PascalChamps sur Marne77455 Marne la Vallée Cedex 2France AndraParc de la Croix-Blanche1-7 rue Jean Monnet92298 Ch■tenay-Malabry cedexFrance

We propose and analyze a posteriori energy-norm error estimates for weighted interior penalty discontinuous Galerkin approximations of advection-diffusion-reaction equations with heterogeneous and anisotropic diffusion. The weights, which play a key role in the analysis, depend on the diffusion tensor and are used to formulate the consistency terms in the discontinuous Galerkin method. The error upper bounds, in which all the constants are specified, consist of three terms： a residual estimator which depends only on the elementwise fluctuation of the discrete solution residual, a diffusive flux estimator where the weights used in the method enter explicitly, and a non-conforming estimator which is nonzero because of the use of discontinuous finite element spaces. The three estimators can be bounded locally by the approximation error. A particular attention is given to the dependency on problem parameters of the constants in the local lower error bounds. For moderate advection, it is shown that full robustness with respect to diffusion heterogeneities is achieved owing to the specific design of the weights in the discontinuous Galerkin method, while diffusion anisotropies remain purely local and impact the constants through the square root of the condition number of the diffusion tensor. For dominant advection, it is shown, in the spirit of previous work by Verfiirth on continuous finite elements, that the local lower error bounds can be written with constants involving a cut-off for the ratio of local mesh size to the reciprocal of the square root of the lowest local eignevalue of the diffusion tensor.

关键词： Discontinuous Galerkin Weighted interior penalty A posteriori error estimate,Heterogeneous diffusion Advection-diffusion.

Hybrid High‑Order Methods for the Acoustic Wave Equation in the Time Domain

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Communications on Applied Mathematics and Computation 2022年第2期4卷 597-633页

作者： Erik Burman Omar Duran Alexandre ern Department of Mathematics University College LondonLondon WC1E 6BTUK CERMICS Ecole des Ponts77455 Marne la Vallée Cedex 2France INRIA Paris 75589 ParisFrance

We devise hybrid high-order(HHO)methods for the acoustic wave equation in the time *** frst consider the second-order formulation in *** the Newmark scheme for the temporal discretization,we show that the resulting HHO-Newmark scheme is energy-conservative,and this scheme is also amenable to static condensation at each time *** then consider the formulation of the acoustic wave equation as a frst-order system together with singly-diagonally implicit and explicit Runge-Kutta(SDIRK and ERK)***-SDIRK schemes are amenable to static condensation at each time *** HHO-ERK schemes,the use of the mixed-order formulation,where the polynomial degree of the cell unknowns is one order higher than that of the face unknowns,is key to beneft from the explicit structure of the *** results on test cases with analytical solutions show that the methods can deliver optimal convergence rates for smooth solutions of order O(hk+1)in the H1-norm and of order O(h^(k+2))in the L^(2)-***,test cases on wave propagation in heterogeneous media indicate the benefts of using high-order methods.

关键词： Hybrid high-order methods Wave equation Newmark scheme Runge-Kutta scheme

Double-brooding and annual breeding success of great tits in urban and forest habitats

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Current Zoology 2022年第5期68卷 517-525页

作者： Boglárka Bukor Gábor Seress Ivett Pipoly Krisztina Sándor Csenge Sinkovics ernőVincze András Liker Behavioral Ecology Research Group Center for Natural SciencesUniversity of PannoniaVeszprém H-8200Hungary MTA-PE Evolutionary Ecology Research Group University of PannoniaVeszprém H-8200Hungary MTA-ELTE Comparative Ethology Research Group BudapestHungary Department of Biology Theoretical Population Ecology and Evolution GroupLund UniversityLundSweden

Urban areas differ from natural habitats in several environmental features that influence the characteristics of animals living *** example,birds often start breeding seasonally earlier and fledge fewer offspring per brood in cities than in natural ***,longer breeding seasons in cities may increase the frequency of double-brooding in urban compared with nonurban populations,thus potentially increasing urban birds’annual reproductive output and resulting in lower habitat difference in reproductive success than estimated by studies focusing on first clutches *** this study,we investigated 2 urban and 2 forests great tit Parus major populations from 2013 to *** compared the probability of double-brooding and the total number of annually fledged chicks per female between urban and forest habitats,while controlling for the effects of potentially confounding *** was a trend for a higher probability of double-brooding in urban(44%of females)than in forest populations(36%),although this was not consistent between the 2 urban *** produced significantly fewer fledglings annually in the cities than in the forest sites,and this difference was present both within single-and double-brooded ***,double-brooded urban females produced a similar number of fledglings per season as single-brooded forest *** results indicate that double-brooding increases the reproductive success of female great tits in both habitats,but urban females cannot effectively compensate in this way for their lower reproductive output per ***,other mechanisms like increased post-fledging survival can mitigate habitat differences in reproductive success.

关键词： annual reproductive success habitat differences population self-sustainability second brood urban conservation

The Transition of Belt and Road Initiative from 1.0 to 2.0:Challenges and Implications of Green Development

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Fudan Journal of the Humanities and Social Sciences 2023年第3期16卷 293-328页

作者： Rui Wang Khai ern Lee Mazlin Mokhtar Thian Lai Goh Institute for Environment and Development(LESTARI) Universiti Kebangsaan MalaysiaBangiMalaysia School of Management Guizhou University of CommerceGuiyangChina Jeffrey Sachs Center on Sustainable Development Sunway UniversitySunway CityMalaysia Sustainable Development Solutions Network(SDSN)Asia Sunway UniversitySunway CityMalaysia Faculty of Science and Technology Universiti Kebangsaan MalaysiaBangiMalaysia

China claims that the Belt and Road Initiative is a cross-regional comprehensive initiative covering the economy,social and environmental *** it was first proposed,it identified five main areas which call for cooperation priorities,*** coordination,interconnection of facilities,unimpeded trade,financial integration and people-to-people *** globally are focusing on the development of the Belt and Road Initiative as it has gone through several development *** Belt and Road Initiative initially focused on economic development,equal dialogue and cultural interchange between the Belt and Road Initiative partners and China,and now it has added the concept of green *** paper reviews the Belt and Road Initiative documents since 2013 and analyses the changes of environmental policies in the Belt and Road Initiative,aiming to identify the challenges and implications of green *** outcome of this paper provides insight into how the Belt and Road Initiative can contribute towards sustainable development with its partner countries.

关键词： China Belt and Road Initiative Environment Green development Sustainable development

Fast Switching Power Module Solutions for Applications with 1200V Component Rating

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Fast Switching Power Module Solutions for Applications with ...

红十字湖地区伟晶花岗岩及其伟晶岩中钾长石的地球化学演化

2006中国电工技术学会电力电子学会第十届学术年会

作者： Temesi ern Michael Frisch Tyco Electronics Power Systems Finsinger Feld 1.Ottobrunn／Germany Tyco Electronics Power Systems Finsinger Feld 1.Ottobrunn／Germany

＜正＞Power applications are forced to work at higher frequencies. This is caused by increased demand on motor drive with special capabilities for high speed, low noise or ultra high dynamic as well as the fact that higher frequencie reduce the mechanic size of the passive components as transformers, inductors and capacitors. This means if th switching frequency will be increased, the volume will be correspondingly smaller at the same power level. But wit high switching frequencies the challenge is to optimize the overall efficiency of the inverter, as the switching losse become a significant portion of the total losses in the system.

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矿物学报 1992年第1期12卷 18-25页

作者：王贤觉 P.ern■ 中国科学院地球化学研究所广州分部广州510640 加拿大曼尼托巴大学地质系

红十字湖地区伟晶花岗岩-电气石伟晶岩-锂云母伟晶岩系列中的钾长石均为低(最大)微斜长石,Al的有序度高,t_1o≥0.95,△为0.88～0.99。Rb、Cs高达47092ppm和7750ppm,是含Rb、Cs最高的钾长石。Rb、Cs的大量存在导致晶胞参数a,V值明显增大... 详细信息

红十字湖地区伟晶花岗岩-电气石伟晶岩-锂云母伟晶岩系列中的钾长石均为低(最大)微斜长石,Al的有序度高,t_1o≥0.95,△为0.88～0.99。Rb、Cs高达47092ppm和7750ppm,是含Rb、Cs最高的钾长石。Rb、Cs的大量存在导致晶胞参数a,V值明显增大。中等程度的Rb、Cs含量不影响Al的有序化,特别是Al从(t_2o+t_2m)→(t_1m+t_1o)的第一阶段,而高(Rb+Cs)含量(>1%)可以影响Al的有序化过程,特别是Al从t_1m→t_1o的第二阶段。这种影响与温度等条件相比是次要的因素。

关键词：钾长石地球化学伟晶岩花岗岩

Impact of noise on hearing in the military

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Journal of Medical Colleges of PLA(China) 2014年第4期29卷 229-234页

作者： Jenica Su-ern Yong De-Yun Wang Department of Otolaryngology-Head and Neck Surgery National University Health SystemNational University of Singapore

Hearing plays a vital role in the performance of a soldier and is important for speech processing. Noise-induced hearing loss is a significant impairment in the military and can affect combat performance. Military personnel are constantly exposed to high levels of noise and it is not surprising that noise induced hearing loss and tinnitus remain the second most prevalent service-connected disabilities. Unfortunately, unlike civilian personnel, military personnel have little option but to remain in noisy environments in order to complete specific tasks and missions. Use of hearing protection devices and follow-up audiological tests have become the mainstay of prevention of noise-induced hearing loss. This review focuses on sources of noise within the military, pathophysiology and management of patients with noise induced hearing loss.

关键词： Hearing loss,noise-induced Military personnel Ear protective devices

Contrast-Enhanced Mammogram: A New Game-Changer in Breast Imaging. Indications with Case-Based Experience

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Advances in Breast Cancer Research 2021年第4期10卷 184-199页

作者： Chotai Niketa Loke Siu Cheng Tan ern Yu RadLink Diagnostic Imaging Center Visiting Consultant Department of Radiology Tan Tock Seng Hospital Singapore Singapore Department of Diagnostic Imaging Tan Tock Seng Hospital Singapore Singapore Department of Surgery Tan Tock Seng Hospital Singapore Singapore

Mammograms are the mainstay of diagnostic breast imaging and cancer screening. Despite advances in technology such as Full Field Digital Mammography (FFDM) and Digital Breast Tomosynthesis (DBT), these imaging techniques are purely structural, and are unable to overcome shortcomings in mammography posed by dense breast parenchyma. Magnetic Resonance Imaging (MRI) is the most sensitive modality in breast imaging, due to its functional aspects in addition to structural imaging with this modality. The use of MRI is however constrained by cost and availability. The utilization of intravenous contrast with mammograms introduces a functional element to imaging. This greatly improves the sensitivity of the examination, approaching sensitivity levels of Magnetic Resonance Imaging (MRI) in the detection of primary breast cancer. With increased sensitivity afforded by assessment of tumor neo-vascularity, as well as its low cost, low energy imaging that is more readily available than MRI, Contrast-Enhanced Mammography (CEM) if more readily available than MRI, this imaging modality is a potential game

红十字湖地区锂云母-透锂长石伟晶岩脉中锡锰钽矿的发现

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地球化学 2002年第5期31卷 481-486页

作者：王贤觉熊小林 P.ern 中国科学院广州地球化学研究所广东广州510640 Department of Geological Sciences

锡锰钽矿(wodginite)理想式为MnSnTa2O8,Z=4,其结构为锡铁钽矿(ixiolite)结构的有序化形式。它是钽的主要工业矿物,是高度分异演化伟晶岩的标志矿物之一。在加拿大红十字湖地区锂云母-透锂长石伟晶岩脉中发现了这一钽矿物。矿物为黑褐色... 详细信息

锡锰钽矿(wodginite)理想式为MnSnTa2O8,Z=4,其结构为锡铁钽矿(ixiolite)结构的有序化形式。它是钽的主要工业矿物,是高度分异演化伟晶岩的标志矿物之一。在加拿大红十字湖地区锂云母-透锂长石伟晶岩脉中发现了这一钽矿物。矿物为黑褐色,呈半自形,颗粒达0.2mm,分布于由锂云母钠长石构成的条带中,与之共生的是一套典型的、高演化的花岗伟晶岩矿物组合。锡锰钽矿具有Mn/Fe、Sn/Ti、Ta/Nb比值高,杂质少的特点。矿物平均分子式为:Mn1.00(Sn0.64Ta0.24Ti0.04Mn0.04Zn0.02Fe0.01)0.99(Ta1.69Nb0.31)2.00O8;晶胞参数a=0.9534nm,b=1.1482nm,c=0.5123nm,β=91°07',V=0.5607nm3。依据矿物β>91°、V>0.560nm3、对偶面网221与221具强分裂衍射双峰、I021/I220为0.19和Mn/(Fe+Mn)≈1等特征,在锡锰钽矿与锡铁钽矿所构成的同质多像、有序-部分有序-无序这样一个连续系列中,本区所产锡锰钽矿属有序端员矿物,其阳离子在八面体中分布的有序度约为95%。在钽资源的寻找和开发利用中,应重视含锡锰钽矿的锂云母-透锂长石伟晶岩脉。

关键词：红十字湖地区锡锰钽矿床锂云母-透锂长石伟晶岩钽矿物加拿大有序化