Samples of the Cambrian microbial dolomites were collected from Penglaiba section,a well-exposed stratigraphic section in the northwestern area of the Tarim Basin.This study provides an analogue for mediated dolomites...Samples of the Cambrian microbial dolomites were collected from Penglaiba section,a well-exposed stratigraphic section in the northwestern area of the Tarim Basin.This study provides an analogue for mediated dolomites that can precipitate in microbial mats and biofilms.The Cambrian stromatolitic dolomites were studied using high-resolution scanning electron microscopy.The results are as follows:(1)dolomites with 50 nm to 100 nm spherical nanostructures are aggregated into minerals of larger sphericities;(2)nanospherical dolomites of 50 nm to 170 nm diameter are densely arranged as dumbbell-shaped or chained aggregates;(3)silicified filaments,as well as dumbbell-shaped and chain arrangements,are preserved as important microstructures.On the basis of sedimentological,compositional,geochemical,and petrographic data,the microstructures were interpreted as nanoglobules that function as bacteria in the nucleation and filament mineralization stages.The microstructures function as such because they are wrapped in extracellular polymeric substance(EPS)or mucus and mineralized fossils.Silicification accounts for the exceptional preservation of microbial mat structures,including biofilms,as well as filamentous and coccoid microbes.In addition,EPS process is capable of binding different elements,with preference for Si,Mg,and Ca.Such suitable composition favors microbe mineralization and dolomite nucleation on organic substrates.These microscopic structures suggest bacterial mineralization and provide visual evidence for the origin of microbial dolomites.展开更多
IN zoology, the developmental stage of individual from zygote to hatching was called embryo. The modem embryology is a branch of study on the organism’ s embryos. The palaeoembryology is a new field in palaeontology,...IN zoology, the developmental stage of individual from zygote to hatching was called embryo. The modem embryology is a branch of study on the organism’ s embryos. The palaeoembryology is a new field in palaeontology, and it has not been considered an important field before, because the invertebrate’s eggs or embryos are minute size and without mineralized envelope. Until now, fossilized eggs of invertebrates in Cambrian have been rarely reported and most of them are small globular structures without recognizable features. Other reported fossilized embryos found from Middle Cambrian are spherical with a展开更多
After introducing the serious linguistic phenomenon of fossilization, clarifying terms and providing recommendations, the author makes an attempt to expound the various potential causes for fossilized errors from the ...After introducing the serious linguistic phenomenon of fossilization, clarifying terms and providing recommendations, the author makes an attempt to expound the various potential causes for fossilized errors from the biological, social-affective, cultural, cognitive, pedagogical and environmental perspectives and, in addition, suggests the relevance for EFL education in China and some ways of preventing the occurrence of fossilized errors. The paper is concerned with questions of etiology, rather than questions of ontology, so the focus of the paper is on the causal factors for fossilized errors in the interlanguage, including learner-specific factors and non learner-specific factors, such as biological, affective, language transfer, pedagogical, social and ideological culture, and environmental factors. It is proposed that prevention of fossilization is more significant than de-fossilization.展开更多
The discovery of Hamipterus tianshanensis had important scientific significance because three-dimensional preserved fossils can provide unique information about the reproduction,development,and evolution of pterosaurs...The discovery of Hamipterus tianshanensis had important scientific significance because three-dimensional preserved fossils can provide unique information about the reproduction,development,and evolution of pterosaurs.However,the pterosaur fossils exhibited violent weathering,including noticeable cracking and spalling,since the preservation environment changed dramatically after excavation,which severely influenced the preservation of these fossils and the scientific research conducted on them.To determine the weathering mechanism of these fossil bones,the samples were analyzed using X-ray fluorescence(XRF),Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),scanning electron microscopy and energy dispersive spectrometry(SEM-EDS).The results indicate that calcite is the main mineral in the hollow bones,but it is mixed with a small amount of other minerals,such as quartz,feldspar,and other debris particles.Moreover,the main component of the pterosaur bones is hydroxyapatite,and carbonate has substituted for some of the phosphate(B-type carbonated apatite)in the fossil bones.A small amount of calcite and manganese oxides has precipitated in the vascular canals.The phosphate crystallinity index(PCI)is 4.17.These results indicate that the fossils have undergone severe diagenesis.Apart from these alterations,the fossil bones have high contents of anions and cations such as Cl^(-),NO_(3)^(-),SO_(4)^(2-),Na^(+),and Ca^(2+),and the total content of soluble salts is 35584.41μg g^(-1).Based on these results,it is inferred that the weathering mechanism of the fossil bones is as follows.First,the fragile hollow bones cracked easily because of the enormous thermal stress caused by the dramatic temperature changes in the Gobi Desert and the differences in the thermal expansion coefficients(TEC)of the surrounding rocks,the fossil bones,and the different fillers.Second,a large amount of stress is generated by salt crystallization when the temperature and humidity change,and the pterosaur fossils will be damaged when the crystallization pressure exceeds the tensile strength of the fossils.These results suggest that the preservation of pterosaur fossils requires suitable desalination and consolidation conditions.Moreover,they should be preserved in a constant temperature and humidity environment.展开更多
This report is about the first record of non-avian dinosaur eggs in the Hefei Basin,Anhui Province,China.Based on the combination of elongated egg body,linear ridges on the outer surface and two structure layer,the eg...This report is about the first record of non-avian dinosaur eggs in the Hefei Basin,Anhui Province,China.Based on the combination of elongated egg body,linear ridges on the outer surface and two structure layer,the eggs can be referred to Elongatoolithidae.The gradual boundary between the cone and the column layers as well as the relative thin eggshell(less than 1 mm)indicates its affinity within Elongatoolithus.The eggs are identified as Elongatoolithus oosp.,as they were severely compressed and experienced erosion on both inner and outer surfaces.The discovery of egg fossil in the Hefei Basin offers evidence for stratum comparison in this region and supplements the diversity of egg fossils in Anhui.Meanwhile,this discovery also enriches the paleogeographic distribution of elongatoolithids.展开更多
Carbon Capture,Utilization,and Storage(CCUS)is a crucial technology for achieving carbon neutrality,but it faces significant challenges.Despite substantial investments and policy support,CCUS projects have underperfor...Carbon Capture,Utilization,and Storage(CCUS)is a crucial technology for achieving carbon neutrality,but it faces significant challenges.Despite substantial investments and policy support,CCUS projects have underperformed due to technical difficulties,high costs,and controversies surrounding the fossil fuel industry's involvement.The effectiveness and feasibility of CCUS in reducing carbon emissions remain uncertain.This viewpoint provides a comprehensive analysis of the current state of CCUS technology,examining its potential to reduce carbon emissions,the challenges hindering its deployment,and the strategies needed to overcome these barriers.We discuss the need for a combinatorial approach to unlock CCUS's full potential,and also emphasize the importance of selecting optimal CO_(2)utilization pathways to maximize economic benefits and CO_(2)absorption.Although CCUS faces technical,economic,and social barriers,it can still play a valuable role in mitigating emissions from hard-to-abate sectors when supported by comprehensive strategies and collaborative efforts among governments,industries,and research institutions.By addressing these challenges and investing in innovation,CCUS can contribute to achieving carbon neutrality and building a sustainable,low-carbon future.展开更多
The challenge of establishing top-down constraints for regional emissions of fossil fuel CO_(2)(FFCO_(2))arises from the difficulty in distinguishing between atmospheric CO_(2)concentrations released from fossil fuels...The challenge of establishing top-down constraints for regional emissions of fossil fuel CO_(2)(FFCO_(2))arises from the difficulty in distinguishing between atmospheric CO_(2)concentrations released from fossil fuels and background variability,particularly owing to the influence of terrestrial biospheric fluxes.This necessitates the development of a regional inversion methodology based on atmospheric CO_(2)observations to verify bottom-up estimations independently.This study presents a promising approach for estimating China's FFCO_(2)emissions by incorporating the model residual errors(MREs)of the column-averaged dry-air mole fractions of CO_(2)(XCO_(2))from FFCO_(2)emissions(MREff)retained in the analysis of natural flux optimization.China's FFCO_(2)emissions during the COVID-19 lockdown in 2020 are estimated using the GEOS-Chem adjoint model.The relationship between the MREff and FFCO_(2)is determined using the model based on a regional FFCO_(2)anomaly suggested by posterior NOx emissions from air-quality data assimilation.The MREff is typically one-tenth in magnitude,but some positively skewed outliers exceed 1 ppm because the prior emissions lack lockdown impacts,thereby exerting considerable observation forcing given the satellite retrieval uncertainties.We initialize the FFCO_(2)with posterior NOx emissions and optimize the colinear emission ratio.Synthetic data experiments demonstrate that this approach reduces the FFCO_(2)bias to less than 10%.The real-data experiments estimate 19%lower FFCO_(2)with GOSAT XCO_(2)and 26%lower with OCO-2 XCO_(2)than the bottom-up estimations.This study proves the feasibility of our regional FFCO_(2)inversion,highlighting the importance of addressing the outlier behaviors observed in satellite XCO_(2)retrievals.展开更多
Global Stocktake is an important component of the global climate governance mechanism.The first Global Stocktake under the Paris Agreement in 2023 has clarified collective progress and identified the paths to bridge g...Global Stocktake is an important component of the global climate governance mechanism.The first Global Stocktake under the Paris Agreement in 2023 has clarified collective progress and identified the paths to bridge gaps,but its understanding in the academic and policy communities is not yet systematic and comprehensive.Therefore,this study adopts textual analysis,timeline analysis,and game theory methods to comprehensively analyze the process and outcomes of the first Global Stocktake.The study finds that:①The first Global Stocktake underwent three stages,including scientific enhancement,technical dialogue,and political consensus,and took more than five years to reach the final outcome of the United Arab Emirates(UAE)Consensus in which the 1.5℃temperature control target anchored in the scientific enhancement stage set the general tone for the stocktake.②The first Global Stocktake focused on three specific areas—mitigation,adaptation,means of implementation and support—to fully realize the signaling effect.③The most prominent outcome of the stocktake is the new consensus on“transitioning away from all fossil fuels in energy systems”,which specifies the direction for countries to update their nationally determined contributions in 2025 and for the international community to conduct the second Global Stocktake in 2028.④The four groups of countries,namely,developed countries,emerging economies,hydrocarbon-exporting-oriented economies,and climate-vulnerable countries,have different interests and hold distinct core positions,which constrain each other but advance the global stocktake process as a whole.⑤The outcomes of the stocktake are comprehensive and systematic,with as many as 196 consensus items;however,the detailed targets for the three major focus areas are unclear and rigid,and need to be strengthened in the second global stocktake.The study suggests that,on the one hand,China needs to strengthen its policy research in the light of the outcomes of the first Global Stocktake and prepare for the submission of updated nationally determined contribution in 2025 for 2035,which should be consistent with the 1.5℃temperature control target.On the other hand,China should continue to take advantage of the zero-carbon industry to lead global climate change action and expand national development right and international communication capacity.展开更多
Natural gas hydrate(NGH),as a widely recognized clean energy,has shown a significant resource potential.However,due to the lack of a unified evaluation methodology and the difficult determination of key parameters,the...Natural gas hydrate(NGH),as a widely recognized clean energy,has shown a significant resource potential.However,due to the lack of a unified evaluation methodology and the difficult determination of key parameters,the evaluation results of global NGH resource are greatly different.This paper establishes a quantitative relationship between NGH resource potential and conventional oil and gas resource and a NGH resource evaluation model based on the whole petroleum system(WPS)and through the analysis of dynamic field controlling hydrocarbon accumulation.The global NGH initially in-place and recoverable resources are inverted through the Monte Carlo simulation,and verified by using the volume analogy method based on drilling results and the trend analysis method of previous evaluation results.The proposed evaluation model considers two genetic mechanisms of natural gas(biological degradation and thermal degradation),surface volume conversion factor difference between conventional natural gas and NGH,and the impacts of differences in favorable distribution area and thickness and in other aspects on the results of NGH resource evaluation.The study shows that the global NGH initially in-place and recoverable resources are 99×10^(12) m^(3) and 30×10^(12) m3,with averages of 214×10^(12) m^(3) and 68×10^(12) m^(3),respectively,less than 5% of the total conventional oil and gas resources,and they can be used as a supplement for the future energy of the world.The proposed NGH resource evaluation model creates a new option of evaluation method and technology,and generates reliable data of NGH resource according to the reliability comprehensive analysis and test,providing a parameter basis for subsequent NGH exploration and development.展开更多
The micromammal fossils collected from the Shangzhuang Formation of the Linxia Basin,Gansu,are described here.The assemblage consists of 16 species of 13 genera belonging to 7 families,including one new species and on...The micromammal fossils collected from the Shangzhuang Formation of the Linxia Basin,Gansu,are described here.The assemblage consists of 16 species of 13 genera belonging to 7 families,including one new species and one taxon previously unknown from China.Among them 5 genera are Oligocene holdovers and 11 genera/species are known to make their first appearances in Early Miocene,indicating an Early Miocene age for the Gucheng Fauna.The absence of Oligocene survivors such as Tataromys,Yindirtemys,Eucricetodon and Tachyoryctoides,which usually occur in the Xiejian age of Early Miocene,and the presence of newcomers Protalactaga,Megacricetodon and Gobicricetodon,that made their first appearance only in the Shanwangian age of late Early Miocene,suggest that the Gucheng Fauna is of a later age of Early Miocene.The new species,Sinolagomys guchengensis,showing more derived morphology than in S.ulunguensis,seems to support an assessment of the fauna in Shanwangian age.Thus,the Gucheng Fauna may belong to late Early Miocene Shanwangian,partially equivalent to MN 3/4 of the European land mammal zonation.Ecological analysis of the fauna indicates that the palaeoecological condition of the Gucheng area might still be a predominantly arid shrub-steppe in late Early Miocene.展开更多
Beginning from the industrial revolution,non-renewable fossil fuels have powered the population growth and economic expansion.However,the overdependence of such energy sources leads to serious eco-crisis and energy se...Beginning from the industrial revolution,non-renewable fossil fuels have powered the population growth and economic expansion.However,the overdependence of such energy sources leads to serious eco-crisis and energy security issues.As shown in Fig.1,the emissions of CO_(2) greenhouse gas are rising year by year because of the significant amount consumption of fossil energy[1].Searching sustainable energy technologies to achieve carbon neutrality has thus become an urgent task for the future of human society[2].As the most abundant and inexhaustible energy source,sunlight has brought dawn to the opportunities for a sustainable society.Owing to the diurnal and seasonal cycles,the solar energy has the intermittent character,which limits its applications.展开更多
The fossil shells on the sedimentary rocks were collected from The Historical Park,Ban Sap Noi Geopark,Phetchabun Province,Thailand.However,the fossils remained in this area were investigated on the characteristic spe...The fossil shells on the sedimentary rocks were collected from The Historical Park,Ban Sap Noi Geopark,Phetchabun Province,Thailand.However,the fossils remained in this area were investigated on the characteristic species only in geological studies with taxonomy for fossil age predicting.To fill up the gap of these studies,the material characterization techniques were used to study the chemical composition and structure of fossil shells I,II and III.The results clearly showed that the morphologies of all fossil shells were Brachiopod fossils with different species.The functional group and elemental composition of all fossil shells showed that the high content of calcium carbonate was a major composition.In addition,the high content of quartz indicated the silica precipitation phenomenon in all fossil shells.The element composition of cross-sectional morphology and energy dispersive spectroscope (EDS mapping) were used to confirm the presence of Si element in each zone of fossil shells.The crystal structures of all fossil shells were investigated and indicated that the calcium carbonate compound was a calcite phase and silicon dioxide compound was a quartz phase.Moreover,the crystal structure of quartz phase was used to calculate the crystallinity index.The crystallinity index values in all fossil shells indicated a well-crystallized quartz.The age of fossil shells was estimated and found to be brachiopod fossil in carboniferous period with the age of about 359.2 to 299.0 million years.展开更多
In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to sign...In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to significant environmental issues[1].Currently,sustainable biomass resources have attracted much attention as potential substitutes to fossil fuels for producing biofuels and commodity chemicals[2].展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.41402102)Fundamental Research Funds for the Central Universities(Grant No.2652014001)+1 种基金the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2011ZX05005–002–008HZ)National Basic Research Program of China(Grant No.2011CB201100–03)
文摘Samples of the Cambrian microbial dolomites were collected from Penglaiba section,a well-exposed stratigraphic section in the northwestern area of the Tarim Basin.This study provides an analogue for mediated dolomites that can precipitate in microbial mats and biofilms.The Cambrian stromatolitic dolomites were studied using high-resolution scanning electron microscopy.The results are as follows:(1)dolomites with 50 nm to 100 nm spherical nanostructures are aggregated into minerals of larger sphericities;(2)nanospherical dolomites of 50 nm to 170 nm diameter are densely arranged as dumbbell-shaped or chained aggregates;(3)silicified filaments,as well as dumbbell-shaped and chain arrangements,are preserved as important microstructures.On the basis of sedimentological,compositional,geochemical,and petrographic data,the microstructures were interpreted as nanoglobules that function as bacteria in the nucleation and filament mineralization stages.The microstructures function as such because they are wrapped in extracellular polymeric substance(EPS)or mucus and mineralized fossils.Silicification accounts for the exceptional preservation of microbial mat structures,including biofilms,as well as filamentous and coccoid microbes.In addition,EPS process is capable of binding different elements,with preference for Si,Mg,and Ca.Such suitable composition favors microbe mineralization and dolomite nucleation on organic substrates.These microscopic structures suggest bacterial mineralization and provide visual evidence for the origin of microbial dolomites.
文摘IN zoology, the developmental stage of individual from zygote to hatching was called embryo. The modem embryology is a branch of study on the organism’ s embryos. The palaeoembryology is a new field in palaeontology, and it has not been considered an important field before, because the invertebrate’s eggs or embryos are minute size and without mineralized envelope. Until now, fossilized eggs of invertebrates in Cambrian have been rarely reported and most of them are small globular structures without recognizable features. Other reported fossilized embryos found from Middle Cambrian are spherical with a
文摘After introducing the serious linguistic phenomenon of fossilization, clarifying terms and providing recommendations, the author makes an attempt to expound the various potential causes for fossilized errors from the biological, social-affective, cultural, cognitive, pedagogical and environmental perspectives and, in addition, suggests the relevance for EFL education in China and some ways of preventing the occurrence of fossilized errors. The paper is concerned with questions of etiology, rather than questions of ontology, so the focus of the paper is on the causal factors for fossilized errors in the interlanguage, including learner-specific factors and non learner-specific factors, such as biological, affective, language transfer, pedagogical, social and ideological culture, and environmental factors. It is proposed that prevention of fossilization is more significant than de-fossilization.
基金the National Natural Science Foundation of China(Grant Nos.41572020&41688103)the Youth Innovation Promotion Association of CAS(Grant No.2019075)the Foundation of Excavation and Protection from the Hami Government。
文摘The discovery of Hamipterus tianshanensis had important scientific significance because three-dimensional preserved fossils can provide unique information about the reproduction,development,and evolution of pterosaurs.However,the pterosaur fossils exhibited violent weathering,including noticeable cracking and spalling,since the preservation environment changed dramatically after excavation,which severely influenced the preservation of these fossils and the scientific research conducted on them.To determine the weathering mechanism of these fossil bones,the samples were analyzed using X-ray fluorescence(XRF),Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),scanning electron microscopy and energy dispersive spectrometry(SEM-EDS).The results indicate that calcite is the main mineral in the hollow bones,but it is mixed with a small amount of other minerals,such as quartz,feldspar,and other debris particles.Moreover,the main component of the pterosaur bones is hydroxyapatite,and carbonate has substituted for some of the phosphate(B-type carbonated apatite)in the fossil bones.A small amount of calcite and manganese oxides has precipitated in the vascular canals.The phosphate crystallinity index(PCI)is 4.17.These results indicate that the fossils have undergone severe diagenesis.Apart from these alterations,the fossil bones have high contents of anions and cations such as Cl^(-),NO_(3)^(-),SO_(4)^(2-),Na^(+),and Ca^(2+),and the total content of soluble salts is 35584.41μg g^(-1).Based on these results,it is inferred that the weathering mechanism of the fossil bones is as follows.First,the fragile hollow bones cracked easily because of the enormous thermal stress caused by the dramatic temperature changes in the Gobi Desert and the differences in the thermal expansion coefficients(TEC)of the surrounding rocks,the fossil bones,and the different fillers.Second,a large amount of stress is generated by salt crystallization when the temperature and humidity change,and the pterosaur fossils will be damaged when the crystallization pressure exceeds the tensile strength of the fossils.These results suggest that the preservation of pterosaur fossils requires suitable desalination and consolidation conditions.Moreover,they should be preserved in a constant temperature and humidity environment.
文摘This report is about the first record of non-avian dinosaur eggs in the Hefei Basin,Anhui Province,China.Based on the combination of elongated egg body,linear ridges on the outer surface and two structure layer,the eggs can be referred to Elongatoolithidae.The gradual boundary between the cone and the column layers as well as the relative thin eggshell(less than 1 mm)indicates its affinity within Elongatoolithus.The eggs are identified as Elongatoolithus oosp.,as they were severely compressed and experienced erosion on both inner and outer surfaces.The discovery of egg fossil in the Hefei Basin offers evidence for stratum comparison in this region and supplements the diversity of egg fossils in Anhui.Meanwhile,this discovery also enriches the paleogeographic distribution of elongatoolithids.
基金funding from the National Natural Science Foundation of China(62074123)Key Research and Development Plan of Shaanxi Province(No.2024GXZDCYL-01-06)China National Petroleum Corporation(CNPC)Basic Research and Strategic Reserve Technology Research Fund Project(No.2023DQ03-26).
文摘Carbon Capture,Utilization,and Storage(CCUS)is a crucial technology for achieving carbon neutrality,but it faces significant challenges.Despite substantial investments and policy support,CCUS projects have underperformed due to technical difficulties,high costs,and controversies surrounding the fossil fuel industry's involvement.The effectiveness and feasibility of CCUS in reducing carbon emissions remain uncertain.This viewpoint provides a comprehensive analysis of the current state of CCUS technology,examining its potential to reduce carbon emissions,the challenges hindering its deployment,and the strategies needed to overcome these barriers.We discuss the need for a combinatorial approach to unlock CCUS's full potential,and also emphasize the importance of selecting optimal CO_(2)utilization pathways to maximize economic benefits and CO_(2)absorption.Although CCUS faces technical,economic,and social barriers,it can still play a valuable role in mitigating emissions from hard-to-abate sectors when supported by comprehensive strategies and collaborative efforts among governments,industries,and research institutions.By addressing these challenges and investing in innovation,CCUS can contribute to achieving carbon neutrality and building a sustainable,low-carbon future.
基金jointly supported by the National Key Research and Development Plan(Grant No.2023YFB3907405)the National Natural Science Foundation of China(Grant No.42175132)the Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.YSBR-037)。
文摘The challenge of establishing top-down constraints for regional emissions of fossil fuel CO_(2)(FFCO_(2))arises from the difficulty in distinguishing between atmospheric CO_(2)concentrations released from fossil fuels and background variability,particularly owing to the influence of terrestrial biospheric fluxes.This necessitates the development of a regional inversion methodology based on atmospheric CO_(2)observations to verify bottom-up estimations independently.This study presents a promising approach for estimating China's FFCO_(2)emissions by incorporating the model residual errors(MREs)of the column-averaged dry-air mole fractions of CO_(2)(XCO_(2))from FFCO_(2)emissions(MREff)retained in the analysis of natural flux optimization.China's FFCO_(2)emissions during the COVID-19 lockdown in 2020 are estimated using the GEOS-Chem adjoint model.The relationship between the MREff and FFCO_(2)is determined using the model based on a regional FFCO_(2)anomaly suggested by posterior NOx emissions from air-quality data assimilation.The MREff is typically one-tenth in magnitude,but some positively skewed outliers exceed 1 ppm because the prior emissions lack lockdown impacts,thereby exerting considerable observation forcing given the satellite retrieval uncertainties.We initialize the FFCO_(2)with posterior NOx emissions and optimize the colinear emission ratio.Synthetic data experiments demonstrate that this approach reduces the FFCO_(2)bias to less than 10%.The real-data experiments estimate 19%lower FFCO_(2)with GOSAT XCO_(2)and 26%lower with OCO-2 XCO_(2)than the bottom-up estimations.This study proves the feasibility of our regional FFCO_(2)inversion,highlighting the importance of addressing the outlier behaviors observed in satellite XCO_(2)retrievals.
基金supported by the National Natural Science Foundation of China“Study on the Construction of China’s Economic Transformation Model Toward Carbon Neutrality”[Grant No.72140001].
文摘Global Stocktake is an important component of the global climate governance mechanism.The first Global Stocktake under the Paris Agreement in 2023 has clarified collective progress and identified the paths to bridge gaps,but its understanding in the academic and policy communities is not yet systematic and comprehensive.Therefore,this study adopts textual analysis,timeline analysis,and game theory methods to comprehensively analyze the process and outcomes of the first Global Stocktake.The study finds that:①The first Global Stocktake underwent three stages,including scientific enhancement,technical dialogue,and political consensus,and took more than five years to reach the final outcome of the United Arab Emirates(UAE)Consensus in which the 1.5℃temperature control target anchored in the scientific enhancement stage set the general tone for the stocktake.②The first Global Stocktake focused on three specific areas—mitigation,adaptation,means of implementation and support—to fully realize the signaling effect.③The most prominent outcome of the stocktake is the new consensus on“transitioning away from all fossil fuels in energy systems”,which specifies the direction for countries to update their nationally determined contributions in 2025 and for the international community to conduct the second Global Stocktake in 2028.④The four groups of countries,namely,developed countries,emerging economies,hydrocarbon-exporting-oriented economies,and climate-vulnerable countries,have different interests and hold distinct core positions,which constrain each other but advance the global stocktake process as a whole.⑤The outcomes of the stocktake are comprehensive and systematic,with as many as 196 consensus items;however,the detailed targets for the three major focus areas are unclear and rigid,and need to be strengthened in the second global stocktake.The study suggests that,on the one hand,China needs to strengthen its policy research in the light of the outcomes of the first Global Stocktake and prepare for the submission of updated nationally determined contribution in 2025 for 2035,which should be consistent with the 1.5℃temperature control target.On the other hand,China should continue to take advantage of the zero-carbon industry to lead global climate change action and expand national development right and international communication capacity.
基金Supported by the Major Consultation Project of the Chinese Academy of Sciences(2019-ZW11-Z-035)Technology Development Project of PetroChina Research Institute of Petroleum Exploration&Development(2021DJ0101)。
文摘Natural gas hydrate(NGH),as a widely recognized clean energy,has shown a significant resource potential.However,due to the lack of a unified evaluation methodology and the difficult determination of key parameters,the evaluation results of global NGH resource are greatly different.This paper establishes a quantitative relationship between NGH resource potential and conventional oil and gas resource and a NGH resource evaluation model based on the whole petroleum system(WPS)and through the analysis of dynamic field controlling hydrocarbon accumulation.The global NGH initially in-place and recoverable resources are inverted through the Monte Carlo simulation,and verified by using the volume analogy method based on drilling results and the trend analysis method of previous evaluation results.The proposed evaluation model considers two genetic mechanisms of natural gas(biological degradation and thermal degradation),surface volume conversion factor difference between conventional natural gas and NGH,and the impacts of differences in favorable distribution area and thickness and in other aspects on the results of NGH resource evaluation.The study shows that the global NGH initially in-place and recoverable resources are 99×10^(12) m^(3) and 30×10^(12) m3,with averages of 214×10^(12) m^(3) and 68×10^(12) m^(3),respectively,less than 5% of the total conventional oil and gas resources,and they can be used as a supplement for the future energy of the world.The proposed NGH resource evaluation model creates a new option of evaluation method and technology,and generates reliable data of NGH resource according to the reliability comprehensive analysis and test,providing a parameter basis for subsequent NGH exploration and development.
文摘The micromammal fossils collected from the Shangzhuang Formation of the Linxia Basin,Gansu,are described here.The assemblage consists of 16 species of 13 genera belonging to 7 families,including one new species and one taxon previously unknown from China.Among them 5 genera are Oligocene holdovers and 11 genera/species are known to make their first appearances in Early Miocene,indicating an Early Miocene age for the Gucheng Fauna.The absence of Oligocene survivors such as Tataromys,Yindirtemys,Eucricetodon and Tachyoryctoides,which usually occur in the Xiejian age of Early Miocene,and the presence of newcomers Protalactaga,Megacricetodon and Gobicricetodon,that made their first appearance only in the Shanwangian age of late Early Miocene,suggest that the Gucheng Fauna is of a later age of Early Miocene.The new species,Sinolagomys guchengensis,showing more derived morphology than in S.ulunguensis,seems to support an assessment of the fauna in Shanwangian age.Thus,the Gucheng Fauna may belong to late Early Miocene Shanwangian,partially equivalent to MN 3/4 of the European land mammal zonation.Ecological analysis of the fauna indicates that the palaeoecological condition of the Gucheng area might still be a predominantly arid shrub-steppe in late Early Miocene.
基金supported by the National Natural Science Foundation of China(No.52202321)the Starting Research Funds of Hefei University of Technology.
文摘Beginning from the industrial revolution,non-renewable fossil fuels have powered the population growth and economic expansion.However,the overdependence of such energy sources leads to serious eco-crisis and energy security issues.As shown in Fig.1,the emissions of CO_(2) greenhouse gas are rising year by year because of the significant amount consumption of fossil energy[1].Searching sustainable energy technologies to achieve carbon neutrality has thus become an urgent task for the future of human society[2].As the most abundant and inexhaustible energy source,sunlight has brought dawn to the opportunities for a sustainable society.Owing to the diurnal and seasonal cycles,the solar energy has the intermittent character,which limits its applications.
基金supported by the Science Achievement Scholarship of Thailand (SAST)the support of Office of Atom for Peace,Thailand and Thailand Institute of Nuclear Technology (a public organization) for providing facilities for some experiment in this work。
文摘The fossil shells on the sedimentary rocks were collected from The Historical Park,Ban Sap Noi Geopark,Phetchabun Province,Thailand.However,the fossils remained in this area were investigated on the characteristic species only in geological studies with taxonomy for fossil age predicting.To fill up the gap of these studies,the material characterization techniques were used to study the chemical composition and structure of fossil shells I,II and III.The results clearly showed that the morphologies of all fossil shells were Brachiopod fossils with different species.The functional group and elemental composition of all fossil shells showed that the high content of calcium carbonate was a major composition.In addition,the high content of quartz indicated the silica precipitation phenomenon in all fossil shells.The element composition of cross-sectional morphology and energy dispersive spectroscope (EDS mapping) were used to confirm the presence of Si element in each zone of fossil shells.The crystal structures of all fossil shells were investigated and indicated that the calcium carbonate compound was a calcite phase and silicon dioxide compound was a quartz phase.Moreover,the crystal structure of quartz phase was used to calculate the crystallinity index.The crystallinity index values in all fossil shells indicated a well-crystallized quartz.The age of fossil shells was estimated and found to be brachiopod fossil in carboniferous period with the age of about 359.2 to 299.0 million years.
基金funded by the Master,PhD Scholarship Programme of Vingroup Innovation Foundation(VINIF),code VINIF.2024.TS.035funded by Vietnam National University,Ho Chi Minh City(VNUHCM)under grant number NCM2024-18-01。
文摘In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to significant environmental issues[1].Currently,sustainable biomass resources have attracted much attention as potential substitutes to fossil fuels for producing biofuels and commodity chemicals[2].
