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
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
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
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
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
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
基金the National Natural Science Foundation of China(Grant No.92044302)the National Key Research and Development Program(Grant Nos.2020YFA0607801,2022YFE0106500)the National Key Scientific and Technological Infrastructure project“Earth System Numerical Simulation Facility”(EarthLab).
文摘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.
基金sponsored by Major Science and Technology Special Project of CNPC(Grant No.2023ZZ07)。
文摘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.
文摘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.
文摘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.
基金Jilin Provincial Science and Technology Department Project,No.20200201343JCScience and Technology Development Program of Jilin Province,No.20210402013GH.
文摘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.
文摘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.
