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Friction 2024年第4期12卷 796-811页

作者： Samuel BOND Robert l.JACKSON German mills Department of Chemistry and Biochemistry Auburn UniversityAuburn 36849-5412USA Department of Mechanical Engineering Auburn UniversityAuburn 36849-5412USA

leakage currents accelerate surface degradation of metal contacts via small scale arcing across lubricating films,but recent observations suggest that metallic nanoparticle additives in lubricants may be useful to improve contact *** findings prompted a study that examined electrically induced surface pitting of steel contacts in the presence of several lubricating greases including some containing nanometer-sized colloidal silver(Ag)*** rolling sphere-on-disk experiments were conducted under electro-tribological loads employing polyurea greases derived from mineral and synthetic base oils with and without *** forces and electrical resistance were monitored continuously during the tests;surface changes were characterized by means of optical spectroscopy,stylus profilometry,and scanning electron microscopy(SEM)including compositional analysis using energy dispersive spectroscopy(EDS).The observations demonstrate that surface pitting induced by arcing occurs mainly at the points were the rolling motion changes direction and that eroded metal is deposited along the wear ***-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon *** findings indicate a significant inhibition of pitting is induced by the Ag nanoparticles;some greases containing other additives exhibit a similar,although less pronounced,effect.

关键词： electric motor bearings wheel bearings electric vehicles arcing electrically induced bearing damage pitting leakage current stray current

Unifying concepts in methanogenic,aerobic,and anammox sludge granulation

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Environmental Science and Ecotechnology 2024年第1期17卷 17-30页

作者： Simon mills Anna Christine Trego Marco Prevedello Jo De Vrieze Vincent O’Flaherty Piet N.l.lens Gavin Collins Microbial Communities laboratory School of Biological and Chemical SciencesNational University of Ireland GalwayUniversity RoadGalwayH91 TK33Ireland Microbial Ecology laboratory School of Biological and Chemical Sciences University of GalwayUniversity RoadGalwayH91 TK33Ireland Center for Microbial Ecology and Technology(CMET) Ghent UniversityCoupure Links 653B-9000GentBelgium University of Galway University RoadGalwayH91 TK33Ireland

The retention of dense and well-functioning microbial biomass is crucial for effective pollutant removal in several biological wastewater treatment *** solids retention is often achieved through aggregation of microbial communities into dense,spherical aggregates known as granules,which were initially discovered in the *** granules have since been widely applied in upflow anaerobic digesters for waste-to-energy ***,granular biomass has been applied in aerobic wastewater treatment and anaerobic ammonium oxidation(anammox)*** mechanisms underpinning the formation of methanogenic,aerobic,and anammox granules are the subject of ongoing *** each granule type has been extensively studied in isolation,there has been a lack of comparative studies among these granulation *** is likely that there are some unifying concepts that are shared by all three sludge *** these unifying concepts could allow a unified theory of granulation to be ***,we review the granulation mechanisms of methanogenic,aerobic,and anammox granular sludge,highlighting several common concepts,such as the role of extracellular polymeric substances,cations,and operational parameters like upflow velocity and shear *** have then identified some unique features of each granule type,such as different internal structures,microbial compositions,and quorum sensing ***,we propose that future research should prioritize aspects of microbial ecology,such as community assembly or interspecies interactions in individual granules during their formation and growth.

关键词： Granule Granulation Anaerobic digestion Anammox Aerobic granule

ArcFVS:An integration of a Geographic Information System and Forest Vegetation Simulator

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Science China(Technological Sciences) 2006年第Z1期49卷 35-44页

作者： Bogdan Chivoiu John Moser Walter l.mills Department of Forestry and Natural Resources Purdue University 715 West State Street West LafayetteIN 47907USA

This paper presents the design and implementation of an integrated application program called ArcFVS that links the Forest Vegetation Simulator (FVS) and a Geographic Information System (GIS) to realize spatial selection of input files and graphic display of modeling output. Data for testing and running the model came from the U.S. Forest Service's Forest Inventory and Analysis (FIA) Database and were also collected in field surveys in north-central Indiana. ArcFVS 1.0 is designed using the ArcGIS software from the Environmental Systems Research Institute (ESRI) and the Visual Basic for Applications (VBA) programming environment to manipulate ESRI's ArcObjects. The resulting product offers custom functions as commands in a new menu or as tools on a new toolbar. They are used to: select spatially or by attribute the forest plots to be projected by FVS, create the FVS input files for the selected plots and display in a geospatial environment different types of FVS output (text output files, tables with variables of interest and visualization image files). Advantages of ArcFVS 1.0 include the new GIS capabilities, enhanced format translation functions and the standardized programming environment.

关键词： Forest Vegetation Simulator, Geographic Information Systems, forest modeling, graphic interface.

Anthropogenic Influence on Decadal Changes in Concurrent Hot and Dry Events over China around the Mid-1990s

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Advances in Atmospheric Sciences 2024年第2期41卷 233-246页

作者： Qin SU Buwen DONG Fangxing TIAN nicholas P.KlINGAMAN Yunnan Key laboratory of Meteorological Disasters and Climate Resources in the Great Mekong Subregion Yunnan UniversityKunming 650500China Department of Atmospheric Sciences Yunnan UniversityKunming 650500China National Centre for Atmospheric Science Department of MeteorologyUniversity of ReadingReadingRG66BBUK Geofysisk Institut University of BergenBergen 5007Norway Citadel Investment Group Moor House120 London WallLondonRG66BBUK

The frequency and duration of observed concurrent hot and dry events(HDEs) over China during the growing season(April–September) exhibit significant decadal changes across the mid-1990s. These changes are characterized by increases in HDE frequency and duration over most of China, with relatively large increases over southeastern China(SEC), northern China(NC), and northeastern China(NEC). The frequency of HDEs averaged over China in the present day(PD,1994–2011) is double that in the early period(EP, 1964–81);the duration of HDEs increases by 60%. Climate experiments with the Met Office Unified Model(MetUM-GOMl2) are used to estimate the contributions of anthropogenic forcing to HDE decadal changes over China. Anthropogenic forcing changes can explain 60%–70% of the observed decadal changes,suggesting an important anthropogenic influence on HDE changes over China across the mid-1990s. Single-forcing experiments indicate that the increase in greenhouse gas(GHG) concentrations dominates the simulated decadal changes,increasing the frequency and duration of HDEs throughout China. The change in anthropogenic aerosol(AA) emissions significantly decreases the frequency and duration of HDEs over SEC and NC, but the magnitude of the decrease is much smaller than the increase induced by GHGs. The changes in HDEs in response to anthropogenic forcing are mainly due to the response of climatological mean surface air temperatures. The contributions from changes in variability and changes in climatological mean soil moisture and evapotranspiration are relatively small. The physical processes associated with the response of HDEs to GHG and AA changes are also revealed.

关键词： concurrent hot and dry events decadal variation greenhouse gases aerosol emissions

Increased Benthic Algal Primary Production in Response to the Invasive Zebra Mussel (Dreissena polymorpha) in a Productive Ecosystem,Oneida lake,New York

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Journal of Integrative Plant Biology 2008年第11期50卷 1452-1466页

作者： Rebecca K.Cecala Christine M.Mayer Kimberly l.Schulz Edward l.mills Biology Department Syracuse University Biology Deptartment Department of Environmental Sciences and lake Erie Center University of Toledo State University of New York School of Environmental Science and Forestry Cornell Biological Field Station and Department of Natural Resources Cornell University

Increased water clarity associated with zebra mussel （Dreissena polymorpha） populations may favor benthic algal primary production in freshwater systems previously dominated by pelagic phytoplankton production. While zebra mussel-mediated water clarity effects on benthic primary production have been implicated in published reports, few production estimates are available. This study estimates benthic primary production in Oneida lake, NY before and after zebra mussel invasion （1992）, using measured photosynthetic parameters （P^Bmax, α^β and β） from sampled benthic algal communities. In the summers of 2003 and 2004, primary production was measured as O2 evolution from algal communities on hard （cobble） and soft （sediment） substrate from several depths. We also backcast estimates of benthic primary production from measurements of light penetration since 1975. Estimates of whole-lake epipelic and epilithic algal primary production showed a significant （4%） increase and exhibited significantly less interannual variability subsequent to the establishment of zebra mussels. We applied our model to two lakes of differing trophic status; the model significantly overestimated benthic primary production in a hypereutrophic lake, but there was no significant difference between the actual and predicted primary production values in the oligotrophic lake. The hypereutrophic lake had higher zebra mussel densities than Oneida （224 vs. 41 per sample respectively）. Though total community respiration （measured in total darkness） was factored into our model predictions of production, our model may need modification when heterotrophic respiration is a large portion of total community metabolism.

关键词： Dreissena ecosystem engineering nonindigenous species Oneida lake periphyton primary production.

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受控的空气污染物暴露与心律失常风险

环境与职业医学 2014年第10期31卷 787-787页

作者： Jeremy P.langrish Simon J.Watts Amanda J.Hunter Anoop S.V.Shah Jenny A.Bosson Jon Unosson Stefan Barath Magnus lundbck Flemming R.Cassee Ken Donaldson Thomas Sandstrm Anders Blomberg David E.Newby nicholas l.mills

[背景]流行病学研究报道了空气污染暴露与心血管疾病发病率和死亡率增加之间的关联。空气污染物暴露可以影响心脏自主神经节律并降低心率变异性,可能增加心律失常的风险,特别是在敏感的患者群体中。[目的]研究在可控制的空气污染物暴露... 详细信息

[背景]流行病学研究报道了空气污染暴露与心血管疾病发病率和死亡率增加之间的关联。空气污染物暴露可以影响心脏自主神经节律并降低心率变异性,可能增加心律失常的风险,特别是在敏感的患者群体中。[目的]研究在可控制的空气污染物暴露期间和之后,统计分析了健康志愿者和冠状动脉心脏疾病患者的心律失常发生率。[方法]分析数据来自13个随机双盲交叉研究,包括282名参加者(140名健康志愿者和142例稳定性冠状动脉心脏疾病患者)的连续心电图记录。记录研究人群每次暴露时发生心律失常的情况。[结果]在稀释的柴油车尾气、木材烟雾、臭氧、浓缩的环境颗粒物、工程碳纳米颗粒或空气污染高环境水平的暴露期间或者之后,无论在健康志愿者或冠状动脉心脏疾病患者中,任何形式心律失常的发生均没有增加。[结论]急性、可控制的空气污染物暴露不增加受试者发生心律失常的短期风险。研究中所采用的这些技术,对于确定涉及空气污染不利影响的重要病理生理途径依然至关重要,并且在为环境和公共卫生政策决策提供信息中也起着重要的作用。

关键词：空气污染物心律失常短期风险健康志愿者患者群体摘要心脏自主神经心脏疾病

Modeling West Nile Virus transmission in birds and humans:Advantages of using a cellular automata approach

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Infectious Disease Modelling 2024年第1期9卷 278-297页

作者： Baki Cissé David R.lapen KChalvet-Monfray nicholas H.Ogden Antoinette ludwig Public Health Sciences Division National Microbiology LaboratoryPublic Health Agency of CanadaSt-HyacintheCanada Groupe de Recherche enÉpidémiologie des Zoonoses et SantéPublique(GREZOSP) Facultéde Médecine VétérinaireUniversitéde MontréalSaint-HyacintheQuébecCanada Ottawa Research and Development Centre Science and Technology BranchAgriculture and Agri-Food CanadaOttawaK1A 0C6Canada Universitéde lyon INRAEVetAgro SupUMR EPIAMarcy l’EtoileFrance UniversitéClermont Auvergne INRAEVetAgro SupUMR EPIASaint-Genès-ChampanelleFrance

In Canada,the periodic circulation of West Nile Virus(WNV)is difficult to predict and,beyond climatic factors,appears to be related to the migratory movements of infected birds from the southern United *** hypothesis has not yet been explored in a spatially distributed *** main objective of this work was to develop a spatially explicit dynamic model for the transmission of WNV in Canada,that allows us to explore non-climate related hypotheses associated with WNV transmission.A Cellular Automata(CA)approach for multiple hosts(birds and humans)is used for a test region in eastern Ontario,*** tool is designed to explore the role of host and vector spatial heterogeneity,host migration,and vector feeding *** developed a spatialized compartmental SEIRDS-SEI model for WNV transmission with a study region divided into 4 rectangular *** used 2010–2021 bird data from the eBird project and 2010–2019 mosquito data collected by Ontario Public Health to mimic bird and mosquito seasonal *** considered heterogeneous bird densities(high and low suitability areas)and homogeneous mosquito and human *** high suitability areas for birds,we identified 5 entry points for WNV-infected *** compared our simulations with pools of WNV-infected field collected *** and sensitivity analyses were performed using MATlAB *** results showed good correspondence between simulated and observed epidemics,supporting the validity of our model assumptions and *** analysis showed that a 5%increase or decrease in each parameter of our model except for the biting rate of bird by mosquito(c^(B,M)and mosquito natural mortality rate(d^(M)),had a very limited effect on the total number of cases(newly infected birds and humans),prevalence peak,or date of *** demonstrate the utility of the CA approach for studying WNV transmission in a heterogeneous landscape with multiple hosts.

关键词： Cellular automata Mosquito-borne diseases SEIRDS-SEI modeling West Nile Virus

Groupoid Approach to Ergodic Dynamical System of Commutative von Neumann Algebra

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Advances in Pure Mathematics 2024年第3期14卷 167-184页

作者： nicholas O. Okeke Murphy E. Egwe Physical and Mathematical Sciences Dominican University Ibadan Nigeria Department of Mathematics University of Ibadan Ibadan Nigeria

Given a compact and regular Hausdorff measure space (X, μ), with μ a Radon measure, it is known that the generalised space M(X) of all the positive Radon measures on X is isomorphic to the space of essentially bounded functions l∞(X, μ) on X. We confirm that the commutative von Neumann algebras M⊂B(H), with H=l2(X, μ), are unitary equivariant to the maximal ideals of the commutative algebra C(X). Subsequenly, we use the measure groupoid to formulate the algebraic and topological structures of the commutative algebra C(X) following its action on M(X) and define its representation and ergodic dynamical system on the commutative von Neumann algebras of M of B(H) .

关键词： Measure Groupoid Groupoid Equivalence Ergodic Action Convolution Algebra von Neumann Algebra Generalized Space

Olympic Games and 24-hour movement behaviors:A match worth making

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Journal of Sport and Health Science 2024年第6期13卷 728-731页

作者： Mark S.Tremblay nicholas Kuzik Markus J.Duncan Diego Augusto Santos Silva CHEO Research Institute OttawaON K1H 8L1Canada Department of Pediatrics University of OttawaOttawaON K1H 8L1Canada Federal University of Santa Catarina FlorianopolisSanta Catarina 88040-900Brazil

*** The Olympic motto,"Faster,Higher,Stronger-Together",represents the pursuit of athletic excellence,united as a global community."Excellence,respect and friendship"are the Olympic *** the motto and values are multifaceted and holistic in nature,and all-encompassing in their reach while recognizing no single entity rises above the ***,these foundational statements anchor the Olympic movement in its quest to build a better world through sport.

关键词： movement Together pursuit

Towards precision 24-hour movement behavior recommendations—The next new paradigm?

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Journal of Sport and Health Science 2024年第6期13卷 743-748页

作者： Mark S.Tremblay Markus J.Duncan nicholas Kuzik Diego Augusto Santos Silva Valerie Carson CHEO Research Institute OttawaON K1H 8L1Canada Department of Pediatrics University of OttawaOttawaON K1H 8L1Canada Federal University of Santa Catarina Santa Catarina 88040900Brazil Faculty of Kinesiology Sportand RecreationUniversity of AlbertaEdmontonAB T6G 2H9Canada

*** The importance of physical activity(PA)for health is unequivocal.^(1)Accordingly,population-based recommendations for exercise,and more recently public health guidelines for PA,have been developed and released by authoritative groups for many decades.^(2)Such guidelines emerged with leadership from the exercise physiology discipline and were rooted in,and loyal to,the importance of moderate-to-vigorous intensity PA(MVPA)or exercise.

关键词： movement behavior exercise