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Impact of Reservoir Heterogeneity on Bitumen Content in the Mackay River Oil Sands,Athabasca(Canada)
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作者 YANG Xiaofa YU Diyun +6 位作者 WU Suwei REN Junhao CHENG Dingsheng HUANG Jixin YANG Chengyu MA Guoqing LI Meijun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第5期1285-1300,共16页
The Lower Cretaceous Manville Group of Upper Mc Murray Formation is one of the main bitumen reservoirs in Athabasca.In this study,the relationship between reservoirs heterogeneity and bitumen geochemical characteristi... The Lower Cretaceous Manville Group of Upper Mc Murray Formation is one of the main bitumen reservoirs in Athabasca.In this study,the relationship between reservoirs heterogeneity and bitumen geochemical characteristics were analyzed through core and microscopic observation,lab analysis,petrophysics and logging data.Based on the sedimentology framework,the formation environment of high-quality oil sand reservoirs and their significance for development were discussed.The results indicate that four types lithofacies were recognized in the Upper Mc Murray Formation based on their depositional characteristics.Each lithofacies reservoirs has unique physical properties,and is subject to varying degrees of degradation,resulting in diversity of bitumen content and geochemical composition.The tidal bar(TB)or tidal channel(TC)facies reservoir have excellent physical properties,which are evaluated as gas or water intervals due to strong degradation.The reservoir of sand bar(SB)facies was evaluated as oil intervals,due to its poor physical properties and weak degradation.The reservoir of mixed flat(MF)facies is composed of sand intercalated with laminated shale,which is evaluated as poor oil intervals due to its poor connectivity.The shale content in oil sand reservoir is very important for the reservoir physical properties and bitumen degradation degree.In the context of regional biodegradation,oil sand reservoirs with good physical properties will suffer from strong degradation,while oil sand reservoirs with relatively poor physical properties are more conducive to the bitumen preservation. 展开更多
关键词 oil sands reservoir heterogeneity geochemical characteristics bitumen content Upper Mc Murray Formation canada
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Cronkhite-Canada综合征合并无症状新型冠状病毒感染一例
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作者 张宁 杨晨皓 +5 位作者 周良瑞 孙晓红 刘晓红 康琳 李骥 李海龙 《协和医学杂志》 CSCD 北大核心 2024年第2期406-412,共7页
本文报道Cronkhite⁃Canada综合征合并无症状新型冠状病毒感染1例。该患者临床表现为食欲减退,毛发及指甲脱落,皮肤色素沉着。内镜检查见胃、十二指肠及结肠黏膜呈弥漫性、大小不一、密集分布的息肉样改变。病程中检出新型冠状病毒核酸... 本文报道Cronkhite⁃Canada综合征合并无症状新型冠状病毒感染1例。该患者临床表现为食欲减退,毛发及指甲脱落,皮肤色素沉着。内镜检查见胃、十二指肠及结肠黏膜呈弥漫性、大小不一、密集分布的息肉样改变。病程中检出新型冠状病毒核酸阳性。经中等剂量泼尼松治疗后,患者毛发恢复生长,皮肤色素沉着减退。本文总结该患者的诊疗经过并结合文献复习,以期提升临床医生对该病的认知。 展开更多
关键词 Cronkhite⁃canada综合征 新型冠状病毒感染 治疗
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Severe Global Environmental Issues Caused by Canada’s Record-Breaking Wildfires in 2023 被引量:2
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作者 Zhe WANG Zifa WANG +8 位作者 Zhiyin ZOU Xueshun CHEN Huangjian WU Wending WANG Hang SU Fang LI Wenru XU Zhihua LIU Jiaojun ZHU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第4期565-571,共7页
Due to the record-breaking wildfires that occurred in Canada in 2023,unprecedented quantities of air pollutants and greenhouse gases were released into the atmosphere.The wildfires had emitted more than 1.3 Pg CO_(2)a... Due to the record-breaking wildfires that occurred in Canada in 2023,unprecedented quantities of air pollutants and greenhouse gases were released into the atmosphere.The wildfires had emitted more than 1.3 Pg CO_(2)and 0.14 Pg CO_(2)equivalent of other greenhouse gases(GHG)including CH4 and N_(2)O as of 31 August.The wildfire-related GHG emissions constituted more than doubled Canada’s planned cumulative anthropogenic emissions reductions in 10 years,which represents a significant challenge to climate mitigation efforts.The model simulations showed that the Canadian wildfires impacted not only the local air quality but also that of most areas in the northern hemisphere due to long-range transport,causing severe PM_(2.5)pollution in the northeastern United States and increasing daily mean PM_(2.5)concentration in northwestern China by up to 2μg m-3.The observed maximum daily mean PM_(2.5)concentration in New York City reached 148.3μg m-3,which was their worst air quality in more than 50 years,nearly 10 times that of the air quality guideline(i.e.,15μg m-3)issued by the World Health Organization(WHO).Aside from the direct emissions from forest fires,the peat fires beneath the surface might smolder for several months or even longer and release substantial amounts of CO_(2).The substantial amounts of greenhouse gases from forest and peat fires might contribute to the positive feedback to the climate,potentially accelerating global warming.To better understand the comprehensive environmental effects of wildfires and their interactions with the climate system,more detailed research based on advanced observations and Earth System Models is essential. 展开更多
关键词 canada forest fire greenhouse gases PM_(2.5) transboundary air pollution
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Emergency department presentation changes due to the coronavirus disease pandemic in Nova Scotia,Canada
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作者 Tara Dahn Patrick T.Fok +9 位作者 Hana Wiemer Daniel J.Dutton Valancy Cole David Lewis Tong Liu Keith R.Brunt Robert Hanlon Jacqueline Fraser Chris Vaillancourt Paul Atkinson 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2023年第1期62-64,共3页
Multiple studies have reported decreased emergency department(ED)patient volumes during the coronavirus disease(COVID-19)pandemic,[1-6]including areas most affected by the virus.[7]Most existing studies have investiga... Multiple studies have reported decreased emergency department(ED)patient volumes during the coronavirus disease(COVID-19)pandemic,[1-6]including areas most affected by the virus.[7]Most existing studies have investigated general trends in ED presentations and have not examined the impact of COVID-19 on different types of EDs,specific ED patient groups,or illness presentations. 展开更多
关键词 canada DEPARTMENT PATIENT
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Cronkhite-Canada综合征2例并文献复习
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作者 张泽雨 康其乐 +4 位作者 郭驰伟 王农荣 谢桂生 付小君 斯轶凡 《南昌大学学报(医学版)》 2024年第2期98-104,共7页
目的探讨Cronkhite-Canada综合征(Cronkhite-Canada syndrome,CCS)的临床特征、治疗方法及预后。方法收集南昌大学第四附属医院消化内科收治的2例CCS患者的临床资料,结合相关文献,对其诊疗、转归以及长期消化内镜的随访资料进行分析。结... 目的探讨Cronkhite-Canada综合征(Cronkhite-Canada syndrome,CCS)的临床特征、治疗方法及预后。方法收集南昌大学第四附属医院消化内科收治的2例CCS患者的临床资料,结合相关文献,对其诊疗、转归以及长期消化内镜的随访资料进行分析。结果2例患者均以胃息肉病变为突出表现。例1于2013年5月确诊CCS并结肠癌,予外科手术、内镜下部分息肉切除术及营养支持治疗后,患者营养状况明显好转,确诊后2年间进行6次胃镜随访,2015年4月确诊胃窦恶性溃疡,2017年7月死亡。例2于2019年6月入院时诊断不明,结合患者其他症状及体征,诊断为CCS,采用激素治疗效果不佳,后因病情进展行全胃切除,术后随访2年,目前病情稳定。结论CCS病情多呈进行性加重,具有恶变趋势,治疗上以糖皮质激素为主,必要时可考虑切除严重病变部位,长期消化内镜下随访有助于诊断疾病及发现早期癌变。 展开更多
关键词 CRONKHITE-canada综合征 外胚层改变 胃镜随访 病例报告
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The Logistics of Production and Supply of Ag Pellets for Industrial Applications in Canada
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作者 Shahabaddine Sokhansanj Mahmood Ebadian +1 位作者 Hamid Rezaei Fahimeh Yazdanpanah 《Journal of Sustainable Bioenergy Systems》 CAS 2023年第1期40-55,共16页
In this work we analyze the supply of biomass from field to an in-land or port destination. The biomass is pelletized to increase its bulk density to extend its storage period and for ease of its transport. The pellet... In this work we analyze the supply of biomass from field to an in-land or port destination. The biomass is pelletized to increase its bulk density to extend its storage period and for ease of its transport. The pellet may be used for conversion to chemicals and animal bedding or for straight combustion. We analyzed supply chain in Saskatchewan where there are plenty of crop residues but widely dispersed and harvest seasons are short. We envisioned that the farmer collects bales from field and transports the bales to farmstead during the harvest season. The bales are then processed into pellets using small scale pellet equipment. A custom operator with expertise in pelletization may engage in handling and densifying the biomass. The business case for the mobile mill will be similar to the well established custom grain and forage harvesting operations. The pellets are stored in hopper bottom grain bins at the farmstead. From this point, the handling of pellets would be similar to the handling and marketing of grain. The farmer trucks a specified volume of pellets from farmstead to the nearest elevator where the pellets are transferred to larger bins or silos. Pellets are extracted from silos and loaded onto the rail cars. The Canadian freight rail companies (mainly CN) currently transport over 3 million dry tonne (dt) of wood pellets in rail cars. The pellets are hauled to marine ports on the West Coast or East Coast for export. The cost of delivering ag pellets to biorefinery or to the shipping port is $86.09/dt. This cost does not include the equivalent value of removing biomass from the farm (e.g. fertilizer replacement) and return on investment. The GHG emissions to produce and transport ag pellets add up to 185.9 kg of CO<sub>2</sub> per dt of biomass. The cost of producing pellets without drying feedstock is $35.05/dt and the corresponding GHG for palletization amounts $146.30/dt. 展开更多
关键词 canada PELLETS Ag Pellets Supply Chain LOGISTICS Cost GHG Emissions INFRASTRUCTURE
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Cronkhite-Canada综合征1例
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作者 黄九香 施林林 《皮肤性病诊疗学杂志》 2024年第4期266-269,共4页
报告Cronkhite-Canada综合征1例。患者男,68岁,因腹痛、腹泻3个月就诊。皮肤科检查:头发弥漫性稀疏,额顶部明显。上下唇部、双手部、双足底可见对称性弥漫性褐色色素沉着,其上多个绿豆大小的点滴状分布的黑色斑疹,趾指甲远端2/3断裂缺如... 报告Cronkhite-Canada综合征1例。患者男,68岁,因腹痛、腹泻3个月就诊。皮肤科检查:头发弥漫性稀疏,额顶部明显。上下唇部、双手部、双足底可见对称性弥漫性褐色色素沉着,其上多个绿豆大小的点滴状分布的黑色斑疹,趾指甲远端2/3断裂缺如,甲板表面粗糙、凹凸不平无光泽。双上眼睑及小腿出现凹陷性水肿。实验室检查:贫血、低蛋白血症。电子肠镜检查:结肠多发息肉。诊断:Cronkhite-Canada综合征。给予高蛋白等营养支持治疗和对症处理。治疗后贫血及低蛋白血症明显改善,肠息肉暂无复发。目前仍在进一步随访中。 展开更多
关键词 CRONKHITE-canada综合征 色素沉着 脱发 甲营养不良 胃肠道息肉
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Comprehensive treatment and a rare presentation of Cronkhite–Canada syndrome: Two case reports and review of literature
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作者 Yan-Qing Lv Mei-Lan Wang +1 位作者 Tong-Yu Tang Yu-Qin Li 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第11期2646-2656,共11页
BACKGROUND Cronkhite–Canada syndrome(CCS)is a rare sporadic polyposis syndrome that presents with gastrointestinal and ectodermal symptoms in addition to nutritional deficiencies.CCS combined with hypothyroidism is a... BACKGROUND Cronkhite–Canada syndrome(CCS)is a rare sporadic polyposis syndrome that presents with gastrointestinal and ectodermal symptoms in addition to nutritional deficiencies.CCS combined with hypothyroidism is an even rarer condition,with no standard treatment guidelines.CASE SUMMARY The present study described 2 patients with CCS:A 67-year-old woman with concomitant hypothyroidism and 68-year-old man treated with endoscopic mucosal resection(EMR).Both patients had multiple gastrointestinal symptoms and ectodermal changes,along with multiple gastrointestinal polyps.Microscopic examination showed that the mucosa in both patients was hyperemic and edematous,with pathologic examination showing distorted,atrophic,and dilated glands.Patient 1 had concomitant hypothyroidism and was treated with levothyroxine.Due to her self-reduction of hormone dose,her disease relapsed.Patient 2 underwent EMR,but refused further hormonal or biological treatments.Subsequently,he was treated with an oral Chinese medical preparation.CONCLUSION Pharmacotherapy can induce and maintain remission in CCS patients,with adjuvant EMR,long-term follow-up,and endoscopic surveillance being necessary.Case 1:Based on the aforementioned findings,Patient 1 was diagnosed with CCS and hypothyroidism.Case 2:Based on the aforementioned findings,Patient 2 was diagnosed with CCS. 展开更多
关键词 Cronkhite–canada syndrome Clinical features Gastrointestinal polyps HYPOTHYROIDISM Case report
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CPTPP、USMCA、RCEP数字贸易规则的对比及我国的因应
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作者 于跃 《西部学刊》 2024年第2期47-50,共4页
数字贸易规则的制定和参与逐渐成为各国竞争的新兴领域,CPTPP、USMCA、RCEP中数字贸易章节的规则存在许多不同。RCEP致力于减少数字贸易壁垒,同时具有较强的开放包容性;USMCA对跨境数据流动的限制最少且包含最新的议题,但主要目的是为... 数字贸易规则的制定和参与逐渐成为各国竞争的新兴领域,CPTPP、USMCA、RCEP中数字贸易章节的规则存在许多不同。RCEP致力于减少数字贸易壁垒,同时具有较强的开放包容性;USMCA对跨境数据流动的限制最少且包含最新的议题,但主要目的是为了保护美国的国家利益;CPTPP与USMCA重合度较高,与RCEP相比所包含内容更广、规则标准更高。我国可以通过促进国内数字市场逐步开放、对接高标准区域协定规则、积极参与国际合作与谈判的方式,提升我国在数字贸易规则中的竞争力。 展开更多
关键词 CPTPP usmca RCEP 数字贸易规则
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Message from animal models and experimental medicine for 2024-Striving for excellence with distinctive features
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作者 Chuan Qin 《Animal Models and Experimental Medicine》 CAS CSCD 2024年第1期1-1,I0002,共2页
Since its inception,Animal Models and Experimental Medicine(AMEM)has received 632 articles in total from 52 countries and regions includ-ing China,Iran,the United States,India,Nigeria,Israel,Germany,Iraq,Italy,Japan,A... Since its inception,Animal Models and Experimental Medicine(AMEM)has received 632 articles in total from 52 countries and regions includ-ing China,Iran,the United States,India,Nigeria,Israel,Germany,Iraq,Italy,Japan,Australia,Bangladesh,Belgium,Brazil,and Canada,among others.AMEM has become an important international exchange plat-form for innovative research achievements in the field of laboratory animal science and basic medicine. 展开更多
关键词 Israel canada INNOVATIVE
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Study of Canada’s Economic System from a System Thinking Perspective
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作者 Wei Zhang Yuejun Cui 《Proceedings of Business and Economic Studies》 2024年第3期179-187,共9页
This article analyzes Canada’s economic system from a systems thinking perspective.The content includes patterns of public choice(party system and power distribution),organizational framework of decision-making arran... This article analyzes Canada’s economic system from a systems thinking perspective.The content includes patterns of public choice(party system and power distribution),organizational framework of decision-making arrangements,information provision and coordination mechanisms,property rights system,incentive system,and welfare system.Canada’s economic system significantly influences the development of the Canadian economy,and its economic system arrangements hold reference significance for other developed and developing countries. 展开更多
关键词 canada Economic system Party system Power distribution Property rights system
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Inclusive Education in the Context of Ethnocultural Diversity: Understanding the Process of Exclusion to Act in the School - A Secondary Publication
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作者 Marie-Odile Magnan Justine Gosselin-Gagné +1 位作者 Geneviève Audet Xavier Conus 《Journal of Contemporary Educational Research》 2024年第3期124-135,共12页
This paper reveals that the implementation of inclusive education is an unfinished challenge,both within the system and for individual self-improvement.This process of changing practices,by continually questioning the... This paper reveals that the implementation of inclusive education is an unfinished challenge,both within the system and for individual self-improvement.This process of changing practices,by continually questioning the school’s responsibility for the(re)production of inequalities,exclusion,and unequal social relations,is riddled with obstacles,unpredictable situations,and strong emotions.In particular,the researchers point out that many systemic mechanisms of school culture contribute to replicating and reifying hierarchical school experiences and exacerbating processes of institutional discrimination against immigrant backgrounds and/or racialized students.The empirical research presented also highlights the school staff’s deficit thinking toward immigrant students and their parents.The results show that staff tend to use linguistic and cultural gaps between students and the school system to explain academic failure.Be that as it may,the researchers as well as the school actors and students interviewed in this paper suggest multiple ways to improve inclusion in the school context,stressing the importance of giving voice to the various actors in order to move toward institutional transformation. 展开更多
关键词 Educational inclusion and exclusion canada Switzerland
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Metamorphoses of the University and the Pathways of Indigenous Students in Quebec:Issues of Accessibility to Studies and Academic Persistence from a Perspective of the Decolonization of Education-A Secondary Publication
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作者 Jean-Luc Ratel Annie Pilote 《Journal of Contemporary Educational Research》 2024年第4期304-315,共12页
In connection with the historical context of social segregation and the assimilative aim of formal education imposed on them,the Indigenous Peoples of Québec have long been excluded from higher education.Today,ev... In connection with the historical context of social segregation and the assimilative aim of formal education imposed on them,the Indigenous Peoples of Québec have long been excluded from higher education.Today,even if their graduation rates are increasing,a persistent gap with the non-Indigenous population is maintained.The data in this article are drawn from 23 interviews with students and university graduates of the First Nations of Québec,as part of a thesis in educational sciences.Our paper analyzes how these students manage to combine the contributions of Indigenous education with those of Western education by developing paths that are part of the decolonization movement of education.Their relationship to Indigenous identity and cultures clearly influences their educational background and is analyzed taking into account power relations with the dominant culture.Our paper emphasizes more particularly the relationship to studies,the adaptation to the student profession,and the balance between studies,work,and family among Indigenous students,in a context of transition from university to multiversity which contributed to the increase of Indigenous university attendance. 展开更多
关键词 Educational inclusion and exclusion Higher and university education Educational inequalities canada
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Ableism and (Neo)Racism in School Placement Processes in Quebec: School Personnel Interpretations of Immigrant Student Difficulties - A Secondary Publication
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作者 Tya Collins Corina Borri-Anadon 《Journal of Contemporary Educational Research》 2024年第3期148-160,共13页
The school placement processes of students from immigrant backgrounds considered to be in“difficulty”is an international concern at the intersection of works relating to special education and those concerning the sc... The school placement processes of students from immigrant backgrounds considered to be in“difficulty”is an international concern at the intersection of works relating to special education and those concerning the school experiences of students from immigrant backgrounds or racialized groups.The research problem of this article concerns the identification of these students as disabled or as having adjustment or learning difficulties.From a perspective anchored in Disability Critical Race Studies,this ethnographic study documents different interpretations of perceived difficulties made by school actors with regard to seven primary school students from immigrant backgrounds.Five interpretation types are presented:(1)medicalization by dismissal of cultural markers,(2)medicalization by professional constraint,(3)medicalization by cultural deficit,(4)precautionary wait,and(5)cultural differentialism.Our results help to shed light on the special education overrepresentation phenomenon regarding these students and to understand how ableism and(neo)racism contribute to it. 展开更多
关键词 Categorization in education Learning difficulties and students in difficulty Immigration and ethnicity Educational inclusion and exclusion canada
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Relations Between School and Immigrant Families in Albertan Francophone School: Perspectives of Settlement Workers in Schools - A Secondary Publication
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作者 Marianne Jacquet Gwenaëlle André 《Journal of Contemporary Educational Research》 2024年第3期136-147,共12页
In recent years,Francophone schools in Alberta,a province in western Canada,have seen significant ethnocultural diversification of their school population,thus reflecting recent migratory changes in Canada.The populat... In recent years,Francophone schools in Alberta,a province in western Canada,have seen significant ethnocultural diversification of their school population,thus reflecting recent migratory changes in Canada.The population of a Francophone school board located in an agglomeration of Alberta reflects these new migratory trends.A partial ethnodemographic portrait carried out in 2003 in six of its schools indicates that 50%of the pupils come from an immigrant background and come from 23 different countries;mostly from sub-Saharan African countries.This demographic reality,confirmed more than a decade later,represents a major structural change for Francophone schools.In Alberta,as in other Canadian provinces,inclusion is at the heart of discourse and educational practices.With a transformative aim,it intends to promote ethnocultural diversity in the classroom and equal opportunities through school equity practices.This article focuses on the settlement workers in schools responsible for bridging family,community,and school cultures.The analysis of the interviews of the four workers sheds light on and questions both the institutional practices and the personal strategies put in place to face the challenges encountered in this tripartite collaboration. 展开更多
关键词 Educational inclusion and exclusion Immigration and ethnicity Interculturality and multiculturalism Family and education Help for pupils and students Actors in education canada
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CT小肠造影诊断Cronkhite-Canada综合征临床案例分析
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作者 赵雪松 缪飞 +4 位作者 孙菁 董屹寒 张欢 严福华 丁蓓 《CT理论与应用研究(中英文)》 2023年第2期263-270,共8页
Cronkhite-Canada综合征(CCS)是一组以胃肠道弥漫性息肉和外胚层变化为特征的综合征,其临床表现主要为慢性腹泻和吸收不良,由于发病率罕见,早期发现和诊断对医生来说是一个挑战。本文报告1例CCS病例,58岁男性,临床表现为慢性水样腹泻、... Cronkhite-Canada综合征(CCS)是一组以胃肠道弥漫性息肉和外胚层变化为特征的综合征,其临床表现主要为慢性腹泻和吸收不良,由于发病率罕见,早期发现和诊断对医生来说是一个挑战。本文报告1例CCS病例,58岁男性,临床表现为慢性水样腹泻、便血、体重减轻和皮肤变化,包括指甲营养不良和色素沉着;实验室检查结果提示贫血和低蛋白血症;CT小肠造影检查发现全消化道黏膜息肉样增生,高度怀疑CCS,随后行内镜检查证实了该诊断。患者经治疗后,症状明显好转,在近1年的随访中,CT小肠造影和内镜检查均提示明显缓解。本文对该疾病进行文献综述,旨在总结其CT小肠造影表现,以提高临床医生对本病的认识,为CCS的早期诊断提供一定的思路。 展开更多
关键词 CT小肠造影 息肉-色素沉着-脱发-指(趾)甲营养不良综合征 诊断
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Contrasting patterns of river runoff and sea-ice melted water in the Canada Basin 被引量:5
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作者 TONG Jinlu CHEN Min +2 位作者 QIU Yusheng LI Yanping CAO Jianping 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第6期46-52,共7页
The fractions of river runoff and sea-ice melted water in the Canada Basin in summer 2003 were determined by the salinity-δ18O system. The fraction of river runoff (fR) was high in the upper 50 m of the water colum... The fractions of river runoff and sea-ice melted water in the Canada Basin in summer 2003 were determined by the salinity-δ18O system. The fraction of river runoff (fR) was high in the upper 50 m of the water column and decreased with depth and latitude. The signals of the river runoffwere confined to water depths above 200 m. The total amount of river runoff in the Canada Basin was higher than that in other arctic seas, indicating that the Canada Basin is a main storage region for river runoff. The penetration depth of the sea-ice melted water was less than 50 m to the south of 78°N, while it was about 150 m to the north of 78°N. The total amount of sea-ice melted water was much higher to the north of 78°N than to the south of 78°N, indicating the sea-ice melted waters accumulated on the ice edge. The abundant sea-ice melted water on the ice edge was attributed to the earlier melted water in the southern Canada Basin and transported by the Beaufort Gyre or the reinforced melting of sea ice by solar radiation in the polynya. 展开更多
关键词 FRESHWATER canada Basin 18O water mass
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Biodegradation and origin of oil sands in the Western Canada Sedimentary Basin 被引量:7
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作者 Zhou Shuqing Huang Haiping Liu Yuming 《Petroleum Science》 SCIE CAS CSCD 2008年第2期87-94,共8页
The oil sands deposits in the Western Canada Sedimentary Basin (WCSB) comprise of at least 85% of the total immobile bitumen in place in the world and are so concentrated as to be virtually the only such deposits th... The oil sands deposits in the Western Canada Sedimentary Basin (WCSB) comprise of at least 85% of the total immobile bitumen in place in the world and are so concentrated as to be virtually the only such deposits that are economically recoverable for conversion to oil. The major deposits are in three geographic and geologic regions of Alberta: Athabasca, Cold Lake and Peace River. The bitumen reserves have oil gravities ranging from 8 to 12° API, and are hosted in the reservoirs of varying age, ranging from Devonian (Grosmont Formation) to Early Cretaceous (Mannville Group). They were derived from light oils in the southern Alberta and migrated to the north and east for over 100 km during the Laramide Orogeny, which was responsible for the uplift of the Rocky Mountains. Biodegradation is the only process that transforms light oil into bitumen in such a dramatic way that overshadowed other alterations with minor contributions. The levels of biodegradation in the basin increasing from west (non-biodegraded) to east (extremely biodegraded) can be attributed to decreasing reservoir temperature, which played the primary role in controlling the biodegradation regime. Once the reservoir was heated to approximately 80℃, it was pasteurized and no biodegradation would further occur. However, reservoir temperature could not alone predict the variations of the oil composition and physical properties. Compositional gradients and a wide range ofbiodegradation degree at single reservoir column indicate that the water-leg size or the volume ratio of oil to water is one of the critical local controls for the vertical variations ofbiodegradation degree and oil physical properties. Late charging and mixing of the fresh and degraded oils ultimately dictate the final distribution of compositions and physical properties found in the heavy oil and oil sand fields. Oil geochemistry can reveal precisely the processes and levels that control these variations in a given field, which opens the possibility of model-driven prediction of oil properties and sweet spots in reservoirs. 展开更多
关键词 Western canada Sedimentary Basin (WCSB) oil sands BIODEGRADATION MIXING
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Summer water temperature structures and their interannual variation in the upper Canada Basin 被引量:4
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作者 ZHAO Jinping CAO Yong 《Advances in Polar Science》 2011年第4期223-234,共12页
Conductivity, temperature and depth (CTD) data from 1993 2010 are used to study water tempera- ture in the upper Canada Basin. There are four kinds of water temperature structures: The remains of the winter convect... Conductivity, temperature and depth (CTD) data from 1993 2010 are used to study water tempera- ture in the upper Canada Basin. There are four kinds of water temperature structures: The remains of the winter convective mixed layer, the near-surface temperature maximum (NSTM), the wind-driven mixed layer, and the advected water under sea ice. The NSTM mainly appears within the conductive mixed layer that forms in winter. Solar heating and surface cooling are two basic factors in the formation of the NSTM. The NSTM can also appear in undisturbed open water, as long as there is surface cooling. Water in open water areas may advect beneath the sea ice. The overlying sea ice cools the surface of the advected water, and a temperature maximum could appear similar to the NSTM. The NSTM mostly occurred at depths 10-30 m because of its deepening and strengthening during smnmer, with highest frequency at 20 m. Two clear stages of interannual variation are identified. Before 2003, most NSTMs were observed in marginal ice zones and open waters, so temperature maxima were usually warmer than 0~C. After 2004, most NSTMs occurred in ice-covered areas, with nmch colder temperature maxima. Average depths of the temperature maxima in most years were about 20 m, except for about 16 m in 2007, which was related to the extreme minimum of ice cover. Average temperatures were around 0.8~C to 1.1~C, but increased to around 0.5~C in 2004, 2007 and 2009, corresponding to reduced sea ice. As a no-ice summer in the Arctic is expected, the NSTM will be warmer with sea ice decline. Most energy absorbed by seawater has been transported to sea ice and the atmosphere. The heat near the NSTM is only the remains of total absorption, and the energy stored in the NSTM is not considerable. However, the NSTM is an important sign of the increasing absorption of solar energy in seawater. 展开更多
关键词 canada Basin upper ocean near-surface temperature maximum HALOCLINE WARMING
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The Voisey's Bay Ni-Cu-Co Sulfide Deposit, Labrador, Canada: Emplacement of Silicate and Sulfide-Laden Magmas into Spaces Created within a Structural Corridor 被引量:3
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作者 Peter C.Lightfoot Dawn Evans-Lamswood Robert Wheeler 《西北地质》 CAS CSCD 2012年第4期17-38,共22页
The Voisey's Bay Ni-Cu-Co sulfide deposit is hosted in a 1.34 Ga mafic intrusion that is part of the Nain Plutonic Suite in Labrador, Canada.The Ni-Cu-Co sulfide mineralization is associated with magmatic breccias... The Voisey's Bay Ni-Cu-Co sulfide deposit is hosted in a 1.34 Ga mafic intrusion that is part of the Nain Plutonic Suite in Labrador, Canada.The Ni-Cu-Co sulfide mineralization is associated with magmatic breccias that are typically contained in weakly mineralized olivine gabbros, troctolites and ferrogabbros, but also occur as veins in adjacent paragneiss.The mineralization is associated with a dyke-like body which is termed the feeder dyke.This dyke connects the shallow differentiated Eastern Deeps chamber in the east to a deeper intrusion in the west termed the Western Deeps Intrusion.Where the conduit is connected to the Eastern Deeps Intrusion, the Eastern Deeps Deposit is developed at the entry line of the dyke along the steep north wall of the Eastern Deeps Intrusion.The Eastern Deeps Deposit is surrounded by a halo of moderately to weakly mineralized Variable-Textured Troctolite (VTT) that reaches a maximum thickness above the ENE-WSW axis of the Eastern Deeps Deposit. At depth to the west, the conduit is adjacent to the south side of the Western Deeps Intrusion, where the dyke and intrusion contain disseminated magmatic sulfide mineralization.The Reid Brook Zone plunges to the east within the dyke, and both the dyke and adjacent paragneiss are mineralized.The Ovoid Deposit comprises a bowl-shaped body of massive sulfide where the dyke widens near to the present-day surface.It is not clear whether this deposit was developed as a widened-zone within the conduit or at the entry point into a chamber that is now lost to erosion. The massive sulfides and breccia sulfides of the Eastern Deeps are petrologically and chemically different when compared to the disseminated sulfides in the VTT; there is a marked break in Ni tenor (Ni content in 100% sulfide, abbreviated to [Ni]100) and Ni/Co of sulfide between the two.The boundary of the sulfide types is often marked by strong sub-horizontal alignment of heavily digested and metamorphosed paragneiss fragments, development of barren olivine gabbro, and by a change from typically massive sulfides and breccias sulfides into more typical variable-textured troctolites with heavy to weak disseminated sulfide.Sulfides hosted in the feeder dyke tend to have low metal tenors ([Ni]100=2.5%-3.5%); sulfides in Eastern Deeps massive and breccia ores have intermediate Ni tenors ([Ni]100=3.5%-4%) and disseminated sulfides in overlying rocks have high Ni tenors ([Ni] 100=4%-8%) . Conduit-hosted mineralization and mineral zones in the paragneiss adjacent to the Reid Brook Deposit tend to have lower Ni tenor than the Ovoid and Eastern Deeps Deposits.The tenor of mineral hosted in the country rock gneisses tends to be the same as that developed in the conduit ; the injection of the sulfide into the country rocks likely occurred before formation of monosulfide solid solution.The Ovoid Deposit is characterized by coarse-grained loop-textured ores consisting of 10cm-2msized pyrrhotite crystals separated by chalcopyrite and pentlandite.A small lens of massive cubanite surrounded by more magnetite-rich sulfide assemblages represents what appears to be the product of in-situ sulfide fractionation. Detailed exploration in the area between the Reid Brook Zone and the Eastern Deeps has shown that these intrusions and ore deposits are connected by a branched dyke and chamber system in a major westeast fault zone.The Eastern Deeps chamber may be controlled by graben-like fault structures , and the marginal structures appear to have controlled dykes which connect the chambers at different levels in the crust.The geological relationships in the intrusion are consistent with emplacement of the silicate and sulfide laden magma from a deeper sub-chamber (possibly a deep eastward extension of the Western Deeps Intrusion where S-saturation was initially achieved) .The silicate and sulfide magmas were likely emplaced through this conduit into the Eastern Deeps intrusion as a number of different fragment laden pulses of sulfide-silicate melt that evolved with different R factors and in response to some variation in the degree of evolution of the parental magma.S isotope and S/Se data coupled with geological evidence point to a crustal source for the sulfur , and the site of equilibration of mafic magma and crustal S is placed at depth in a sulfidic Tasiuyak Gneiss. The structural control on emplacement of small intrusions with transported sulfide is a feature found in different nickel sulfide deposits around the world.Champagne glass-shaped openings in sub-vertical chonoliths are a common morphology for this deposit type (e.g.the Jinchuan , Huangshan , Huangshandong , Jingbulake , Limahe , Hong Qi Ling deposits in China , the Eagle deposits in the United States , and the Double Eagle deposit in Canada) .Some of the structures of the Midcontinent Rift of North America also host Ni-Cu-(PGE) deposits of this type (e.g.the Current Lake Complex in the Quetico Fault Zone in Ontario , Canada and the Tamarac mineralisation in the Great Lakes Structural Zone of the United States) .Other major nickel deposits associated with flat structures adjacent to major mantle-penetrating structures include the Noril'sk , Noril'sk II , Kharaelakh , NW Talnakh , and NE Talnakh Intrusions of the Noril'sk Region of Russia , the Kalatongke deposit in NW China , and Babel-Nebo in Western Australia.These deposits are all formed in mantle-penetrating structural conduits that link into the roots of large igneous provinces near the edges of old cratons. 展开更多
关键词 Voisey’s Bay Ni-Cu-Co sulfide deposit Labrador canada
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