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sources and environmental fate of pyrogenic polycyclic aromatic hydrocarbons(PAHs)in the Arctic

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Emerging Contaminants 2019年第1期5卷 128-142页

作者： jennifer E.Balmer Hayley Hung Yong Yu Robert j.Letcher derek C.G.Muir Arctic Monitoring and Assessment Programme Fram CentrePO Box 6606 Langnes9296TromsøNorway Department of Biology The Citadel171 Moultrie StreetCharlestonSC29409USA Air Quality Processes Research section Environment and Climate Change Canada4905 Dufferin StreetTorontoOntarioM3H 5T4Canada Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun130102China Ecotoxicology and Wildlife Health Division Environment and Climate Change CanadaNational Wildlife Research CentreCarleton UniversityRaven RoadOttawaOntarioK1A 0H3Canada Environment and Climate Change Canada Canada Centre for Inland Waters867 Lakeshore RoadBurlingtonONL7S 1A1Canada

Polycyclic aromatic hydrocarbons(PAHs)are large class of hydrophobic,semi-volatile organic contaminants that may enter the environment from both natural sources and anthropogenic *** PAHs arise from the incomplete combustion of fossil fuels and organic matter and following dispersal via long-range transport and may subsequently deposit in surface waters,soils and sediments of remote regions,including the *** current review summarizes and discusses Arctic data that is available for combustion-derived PAHs between 2004 and early 2018,focusing largely on data collected from remote,unexploited Arctic regions and from studies that provide some evidence of a pyrogenic *** increasing use of attribution ratios,which aid in discriminating PAHs from petrogenic or pyrogenic sources,suggest PAHs found in Arctic marine waters and sediment predominantly originate from natural underwater seeps,while those measured in air,freshwater,and terrestrial environments are likely to have originated from atmospheric and combustion-derived *** efforts indicate that atmospheric PAHs in the Canadian and Norwegian Arctic are likely to have originated in the northern hemisphere e predominantly from Western Russia,northern Europe,and North *** Asia appears to be a minor source of PAHs to the Arctic,despite contributing more than 50%of global PAH *** comparison to the growing data for atmospheric PAHs,environmental data for these compounds in terrestrial and freshwater environments remain *** have been detected in Arctic biota from terrestrial,freshwater and marine environments,indicating exposure,however,levels are generally low,as most organisms efficiently metabolize parent ***,PAH emissions are expected to decline in the future,however models suggest the Arctic may not experience the same magnitude of decline projected for other world ***,future changes in climate may contribute to a re-volatilizati

关键词： Contaminants Air Biota Pyrogenic Petrogenic Review

Hexachlorobutadiene(HCBD)contamination in the Arctic environment:A review

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Emerging Contaminants 2019年第1期5卷 116-122页

作者： jennifer E.Balmer Hayley Hung Katrin Vorkamp Robert j.Letcher derek C.G.Muir Arctic Monitoring and Assessment Programme Fram CentrePO Box 6606 Langnes9296TromsøNorway Department of Biology The Citadel171 Moultrie StreetCharlestonSC29409USA Air Quality Processes Research section Environment and Climate Change Canada4905 Dufferin StreetTorontoOntarioM3H 5T4Canada Aarhus University Department of Environmental ScienceArctic Research CentreFrederiksborgvej 3994000RoskildeDenmark Ecotoxicology and Wildlife Health Division Environment and Climate Change CanadaNational Wildlife Research CentreCarleton UniversityRaven RoadOttawaOntarioK1A 0H3Canada Environment and Climate Change Canada Canada Centre for Inland Waters867 Lakeshore RoadBurlingtonONL7S 1A1Canada

Hexachlorobutadiene(HCBD)is a halogenated hydrocarbon that is primarily produced as an unintentional byproduct in the manufacture of chlorinated *** between HCBD and other persistent organic pollutants(POPs)led to its listing in 2015 for global regulation under the stockholm Convention on ***'s toxicity and propensity for long-range transport means there is special concern for its potential impacts on Arctic *** present review comprehensively summarizes all available information of the occurrence of HCBD in the Arctic environment,including its atmospheric,terrestrial,freshwater and marine ecosystems and ***,reports of HCBD in Arctic environmental media are *** has been measured in Arctic air collected from monitoring stations in Finland and Canada,yet there is a dearth of data for other abiotic matrices(***,sediments,glacier ice,freshwaters and seawater).Low HCBD concentrations have been measured in Arctic terrestrial and marine biota,which is consistent with laboratory studies that indicate that HCBD has the potential to bioaccumulate,but not to *** data for Arctic biota suggest that terrestrial birds and mammals and seabirds,have comparatively higher HCBD concentrations than fish and marine mammals,warranting additional *** spatial and temporal trends in HCBD concentrations in the Arctic are currently limited,future monitoring of HCBD in the Arctic will be important for assessing the impact of global regulations newly-imposed by the stockholm Convention on POPs.

关键词： POPs Air Biota Contaminants Long-range transport Review

Analysis of the damage mechanism of strainbursts by a global-local modeling approach

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journal of Rock Mechanics and Geotechnical Engineering 2022年第6期14卷 1671-1696页

作者： jun Wang derek B.Apel Artur Dyczko Andrzej Walentek stanislaw Prusek Huawei Xu Chong Wei school of Mining and Petroleum Engineering University of AlbertaEdmontonAlbertaT6G 2R3Canada jastrze˛bska spółka We˛glowa s.A.Group Aleja Jana Pawła II 4Jastrze˛bie-Zdrój44-330Poland Central Mining Institute Plac GwarkówKatowice140-166Poland

strainburst is the most common type of *** research of strainburst damage mechanisms is helpful to improve and optimize the rock support design in the burst-prone *** this study,an improved global-local modeling approach was first adopted to study strainburst damage *** extracted stresses induced by multiple excavations from a three-dimensional(3D)global model established by fast Lagrangian analysis of continua in 3 dimensions(FLAC3D)are used as boundary conditions for a two-dimensional(2D)local model of a deep roadway built by universal distinct element code(UDEC)to simulate realistic stress loading paths and conduct a detailed analysis of rockburst damage from both micro and macro *** results suggest that the deformation and damage level of the roadway gradually increase with the growth of surrounding rock stress caused by the superposition of mining-or excavation-induced stresses of the panel and nearby *** significant increase of surrounding rock stresses will result in more accumulated strain energy in two sidewalls,providing a necessary condition for the strainburst occurrence in the dynamic *** strainburst damage mechanism for the study site combines three types of damage:rock ejection,rock bulking,and *** the strainburst,initiation,propagation,and development of tensile cracks play a crucial role in controlling macroscopic failure of surrounding rock masses,although the shear crack always accounts for the main proportion of damage *** deformation and damage level of the roadway during a strainburst positively correlate with the increasing peak particle velocities(PPVs).The yielding steel arch might not dissipate kinetic energy and mitigate strainburst damage effectively due to the limited energy absorption *** principles to control and mitigate strainburst damage are proposed in this *** study presents a systematic framework to investigate strainburst damage mechanisms

关键词： strainburst Numerical modeling Damage mechanism Finite difference method(FDM) Discrete element method(DEM) Underground mining

Complications arising in simple and polycystic liver cysts

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World journal of Hepatology 2012年第12期4卷 406-411页

作者： Christian Macutkiewicz Ricci Plastow Melissa Chrispijn Rafik Filobbos Basil A Ammori David j sherlock joost PH Drenth derek A O’Reilly Department of HepatoPancreato-Biliary surgery North Manchester General HospitalManchester M8 5RBUnited Kingdom Department of Gastroenterology and Hepatology Radboud University Nijmegen Medical CenterPO Box 9101Code 455 NijmegenThe Netherlands Department of Radiology North Manchester General HospitalManchester M8 5RBUnited Kingdom The University of Manchester Manchester Academic Health Science CentreManchesterUnited Kingdom

Liver cysts are common,affecting 5%-10% of the *** are asymptomatic,however 5% of patients develop symptoms,sometimes due to complications and will require *** is no consensus on their management because complications are so *** aim of this study was to perform a collected review of how a series of complications were managed at our *** different patients presenting with rare complications of liver cysts were obtained from Hepatobiliary Units in the United Kingdom and The *** and radiological imaging were obtained from case notes and computerised *** a result,1 patient admitted with inferior vena cava obstruction was managed by cyst aspiration and lanreotide;1 patient with common bile duct obstruction was first managed by endoscopic retrograde cholangiopancreatography and stenting,followed by open fenestration;1 patient with ruptured cysts and significant medical co-morbidities was managed by percutaneous drainage;1 patient with portal vein occlusion and varices was managed by open liver resection;1 patient with infected cysts was treated with intravenous antibiotics and is awaiting liver *** final patient with a simple liver cyst mimicking a hydatid was managed by open liver *** conclusion,complications of cystic liver disease are rare,and we have demonstrated in this series that both operative and non-operative strategies have defined roles in *** mainstays of treatment are either aspiration/sclerotherapy or,alternatively laparoscopic *** management with somatostatin analogues is a potentially new and exciting treatment option but requires further study.

关键词： Liver Cysts Complications Polycystic

Circling the Blood in the Water: The Difficulties in Endangered species Protections for the Great White shark

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Natural Resources 2014年第11期5卷 666-680页

作者： derek julio s.j. Quinney College of Law Salt Lake City USA

The purpose of legislation like the Endangered species Act is to provide a means to conserve the ecosystems of endangered and threatened species, but not all species that may appear to need conservation are granted protection. An estimated 100 million sharks are killed each year largely due to exploitation, yet few shark species are ever granted protection under state or federal endangered species acts. The Northeastern Pacific population of the Great White shark is no exception. Despite the numerous threats facing the white shark, NOAA denied a petition to list it as an endangered or threatened species under the federal Endangered species Act. In light of the pending California decision to list the white shark under its state endangered species act, this paper considers whether or not such extreme protections are necessary. This paper first discusses the threats facing the white shark, the listing processes of both the federal and the California endangered species acts, and NOAA’s 12-month negative finding. Finally, this paper concludes that endangered species protections are not warranted in the case of the Northeastern Pacific white shark because of prior government intervention and conservation efforts already in place.

关键词： Endangered species Act EsA CEsA California Endangered species Act Great White shark

Cosmological neutrino simulations at extreme scale

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Research in Astronomy and Astrophysics 2017年第8期17卷 89-100页

作者： j.D.Emberson Hao-Ran Yu derek Inman Tong-jie Zhang Ue-Li Pen joachim Harnois-Deraps shuo Yuan Huan-Yu Teng Hong-Ming Zhu Xuelei Chen Zhi-Zhong Xing Canadian Institute for Theoretical Astrophysics University of TorontoM5S 3H8ONCanada Department of Astronomy&Astrophysics University of TorontoTorontoON M5S 3H4Canada ALCF Division Argonne National LaboratoryLemontIL 60439USA Kavli Institute for Astronomy&Astrophysics Peking UniversityBeijing 100871China Department of Astronomy Beijing Normal UniversityBeijing 100875China Department of Physics University of TorontoTorontoONtario M5S IA7Canada school of Physics and Electric Information Shandong Provincial Key Laboratory of BiophysicsDezhou UniversityDezhou 253023China Dunlap Institute for Astronomy and Astrophysics University of TorontoTorontoON M5S 3H4Canada Canadian Institute for Advanced Research Program in cosmology and Gravitation Perimeter Institute for Theoretical Physics WaterlooONN2L 2Y5Canada Department of Physics&Astronomy University of British ColumbiaVancouverBC V6T 1Z1Canada scottish University Physics Alliance Institute for AstronomyUniversity of EdinburghEH93HJScotlandUK Department of Astronomy Peking UniversityBeijing 100871China Key Laboratory for Computational Astrophysics National Astronomical ObservatoriesChinese Academy ofSciencesBeijing 100012China school of Physical sciences University of Chinese Academy of SciencesBeijing 100049China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Constraining neutrino mass remains an elusive challenge in modern *** measurements are expected from several upcoming cosmological probes of large-scale *** this goal relies on an equal level of precision from theoretical predictions of neutrino *** simulations of the non-linear evolution of cold dark matter and neutrinos play a pivotal role in this *** incorporate neutrinos into the cosmological N-body code CUBEP3M and discuss the challenges associated with pushing to the extreme scales demanded by the neutrino *** highlight code optimizations made to exploit modern high performance computing architectures and present a novel method of data compression that reduces the phase-space particle footprint from 24 bytes in single precision to roughly 9 *** scale the neutrino problem to the Tianhe-2 supercomputer and provide details of our production run,named Tian Nu,which uses 86%of the machine(13 824 compute nodes).With a total of 2.97 trillion particles,Tian Nu is currently the world’s largest cosmological N-body simulation and improves upon previous neutrino simulations by two orders of magnitude in *** finish with a discussion of the unanticipated computational challenges that were encountered during the Tian Nu runtime.

关键词： cosmology theory—large-scale structure of universe—methods numerical

spain Continues to Focus Abroad

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机电新产品导报 2006年第9期 126-128,130页

作者： derek Kom TanHui Translated by TanHui

由毕尔包展览中心(BE C)和西班牙机床制造商协会(AF M )联合主办,欧洲机床合作委员会(CE CIM O )协办的 2006年西班牙国际机床展览会(BIE M H 2006)已在西班牙毕尔包成功举行。会上,多家西班牙展商表示,去年公司业绩良好,并预计今年的... 详细信息

由毕尔包展览中心(BE C)和西班牙机床制造商协会(AF M )联合主办,欧洲机床合作委员会(CE CIM O )协办的 2006年西班牙国际机床展览会(BIE M H 2006)已在西班牙毕尔包成功举行。会上,多家西班牙展商表示,去年公司业绩良好,并预计今年的市场环境将普遍向好,显示以出口业务为主的西班牙机床业,已摆脱 2000年起一直衰落的境况,同时也表明西班牙机床制造业、工具及其配件制造商正在考虑向日益增长的国际市场发展。随着行业状况逐渐好转,BIEMH 2006主办单位表示今届展会的成绩超越预期,展商接到的查询中有许多涉及大额交易,预计展商未来数月的订单将可大幅上升。BIEMH 2006共吸引到49168名观众,其中专业买家39706名,来自海外的专业买家人数较上届大幅上升了 17%,整个展览参加人数和展览商比2004年虽略有下降,但是国际与会者以及参加陈述的厂商都比以前有所增加。西班牙国际机床展会上越来越多的迹象表明这个欧洲国家正在被全球金属制造业市场所吸引,这似乎显示着人们越来越关注西班牙机床的技术。西班牙机床配件和工具切割协会期望看到他们的会员公司拓展,Izar刀具公司董事Carlos Pulana认为赢得美国市场的关键在于确定西班牙厂商有能力填补应用的空白, 为了与美国接触, 十家会员公司有意参加2006美国芝加哥国际机械制造技术展览会。今年西班牙国际机床展览会上机床设计趋势呈现出多功能趋势,在自动装卸方面,强调快速变化以及加强利用线性马达驱动器。展览会上大容量的机床应有尽有:如j uaristi & soraluce公司的大型机;此外,一些封闭性机床也在场展示,如 Kondia &Zay er公司的封闭性机床;世界上最老的电火花加工技术设备制造商 O N A则继续关注大容量的电火花加工应用。展会上,Trim ek向人们证实了他们的接触度扫描能力以及扫描可控存储组件的能力。该公司强调结合产品检查,而不是只检查工件以保证产品质量,公司认为商户应根据测量数据的趋势着重检查过程。最近专业设备市场协会的出席者表示在美国发现来自 Autopulit公司的抛光产品,这家可由制造商定制打磨和抛光机器的数控机床制造商,认识到在汽车零配件修理市场有着巨大的商机,尤其是在美国。今年西班牙国际机床展览会的参观者会看到两家公司的并购:Nicolás Correa和Anay ak于近期合并于Nicolás Correa旗下,他们将继续通过各自的独立分支销售自己的产品。IDE KO 研发中心是一个可以由Danobat会员公司分享的联合体,西班牙机床制造商关注着他们的设备设计。以下是一些IDE KO 正在进行以及即将完成的项目:*Danobat 公司的Dano铁轨,它是安装于地下的车床,它能推动火车车轮使得车轮不断重新契合路面以避免火车移动,是一个可以适应不同轨道宽度的移动车床系统。*动态砂轮——该项目利用电压加速安装在一个中心线研磨的旋转滚珠丝杠螺母上以更好地控制研磨头的位置。*电子砂轮修正——运用不接触电子过程控制轮流修正电镀 CBN 齿轮,修正过程中每次修正轮仅仅移除两微米。*超音速震动测试——该项目研究是为了使砂轮表面完好、寿命更长,使用单点砂轮该如何对付震动。这一项目的目标是缩小单点砂轮与转轮使用寿命间的差距。*锭子换代——模具在开发阶段可用电子锭完成半部分粗磨,电子锭有一个内置的系统芯片以消除工作区的碎片,此设备还可用于除尘。*非传统制冷——该项目试验可代替研磨制冷的其他它料,如液体氮和各种干燥剂。

关键词：西班牙机床业国际市场机床制造数控机床