The atmospheric carbon dioxide(CO_(2))concentration has been increasing rapidly since the Industrial Revolution,which has led to unequivocal global warming and crucial environmental change.It is extremely important to...The atmospheric carbon dioxide(CO_(2))concentration has been increasing rapidly since the Industrial Revolution,which has led to unequivocal global warming and crucial environmental change.It is extremely important to investigate the interactions among atmospheric CO_(2),the physical climate system,and the carbon cycle of the underlying surface for a better understanding of the Earth system.Earth system models are widely used to investigate these interactions via coupled carbon-climate simulations.The Chinese Academy of Sciences Earth System Model version 2(CAS-ESM2.0)has successfully fixed a two-way coupling of atmospheric CO_(2)with the climate and carbon cycle on land and in the ocean.Using CAS-ESM2.0,we conducted a coupled carbon-climate simulation by following the CMIP6 proposal of a historical emissions-driven experiment.This paper examines the modeled CO_(2)by comparison with observed CO_(2)at the sites of Mauna Loa and Barrow,and the Greenhouse Gases Observing Satellite(GOSAT)CO_(2)product.The results showed that CAS-ESM2.0 agrees very well with observations in reproducing the increasing trend of annual CO_(2)during the period 1850-2014,and in capturing the seasonal cycle of CO_(2)at the two baseline sites,as well as over northern high latitudes.These agreements illustrate a good ability of CAS-ESM2.0 in simulating carbon-climate interactions,even though uncertainties remain in the processes involved.This paper reports an important stage of the development of CAS-ESM with the coupling of carbon and climate,which will provide significant scientific support for climate research and China’s goal of carbon neutrality.展开更多
The biomass and ratio of root-shoot of Pinus sylvestfthermis seedlings at Co, concentration of 700 μL L-1 and 50 μL-1L-1 were measured using open-top chambers (OTCs) in Changbai Mountain during Jun. to oct. in 1999....The biomass and ratio of root-shoot of Pinus sylvestfthermis seedlings at Co, concentration of 700 μL L-1 and 50 μL-1L-1 were measured using open-top chambers (OTCs) in Changbai Mountain during Jun. to oct. in 1999. The results showed that doubling CO2 concentration was benefit tb seedling growth of the species (500 μL- L1 was better than 700 μLL’ L-1 ) and the biomass production was increased in both aboveground and underground parts of seedlings. Carbon trans formation to roots was evident as rising of CO2 concentration.展开更多
Reactions between CH_4 and CO_2 under the action of continuous microwave discharge at atmospheric pressure were studied in a special homemade reactor. The main products were CO and H2, while acetylene and ethylene wer...Reactions between CH_4 and CO_2 under the action of continuous microwave discharge at atmospheric pressure were studied in a special homemade reactor. The main products were CO and H2, while acetylene and ethylene were also found in the products. Experimental results show that conversions of CH4 and CO2 could be higher than 90% without the presence of any catalyst. Effects of CO2/CH4 molar ratio and total flow rate of the feed gas on the reaction were also investigated.展开更多
The CO_2 in the atmosphere is in contact with water vapor and rain droplets forming CO_2·H_2O, HCO -_3 and CO 2- _3. Global precipitation is about 505×10 15 kg/a. Based on theoretical calculation for ...The CO_2 in the atmosphere is in contact with water vapor and rain droplets forming CO_2·H_2O, HCO -_3 and CO 2- _3. Global precipitation is about 505×10 15 kg/a. Based on theoretical calculation for unpolluted air and measurement observations, we estimated that 100—270×10 12 gC/a are scavenged from the air by global precipitation. This roughly equals carbon emissions from volcanic sources or 2—6 per cent of current CO_2 emissions. An inventory-based estimate on carbon removal in northwestern Europe supports the above calculation on global scale. With increasing CO_2 concentration in the air, precipitation scavenging may increase.展开更多
This paper provides a systematic evaluation of the ability of 12 Earth System Models(ESMs)participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)to simulate the spatial inhomogeneity of the atmospher...This paper provides a systematic evaluation of the ability of 12 Earth System Models(ESMs)participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)to simulate the spatial inhomogeneity of the atmospheric carbon dioxide(CO_(2))concentration.The multi-model ensemble mean(MME)can reasonably simulate the increasing trend of CO_(2) concentration from 1850 to 2014,compared with the observation data from the Scripps CO_(2) Program and CMIP6 prescribed data,and improves upon the CMIP5 MME CO_(2) concentration(which is overestimated after 1950).The growth rate of CO_(2) concentration in the northern hemisphere(NH)is higher than that in the southern hemisphere(SH),with the highest growth rate in the mid-latitudes of the NH.The MME can also reasonably simulate the seasonal amplitude of CO_(2) concentration,which is larger in the NH than in the SH and grows in amplitude after the 1950s(especially in the NH).Although the results of the MME are reasonable,there is a large spread among ESMs,and the difference between the ESMs increases with time.The MME results show that regions with relatively large CO_(2) concentrations(such as northern Russia,eastern China,Southeast Asia,the eastern United States,northern South America,and southern Africa)have greater seasonal variability and also exhibit a larger inter-model spread.Compared with CMIP5,the CMIP6 MME simulates an average spatial distribution of CO_(2) concentration that is much closer to the site observations,but the CMIP6-inter-model spread is larger.The inter-model differences of the annual means and seasonal cycles of atmospheric CO_(2) concentration are both attributed to the differences in natural sources and sinks of CO_(2) between the simulations.展开更多
美国广泛发育具有经济效益的富氦无机成因天然气田,如其中富氦氮气田甚至可以含有高达10%的氦。原地和周边地区的基底提供充足的氦源而氮气可来自不同圈层,且通常N_(2)/He(He>0.1%)在5~50之间。但是富氦氮气田在美国独特地质环境之...美国广泛发育具有经济效益的富氦无机成因天然气田,如其中富氦氮气田甚至可以含有高达10%的氦。原地和周边地区的基底提供充足的氦源而氮气可来自不同圈层,且通常N_(2)/He(He>0.1%)在5~50之间。但是富氦氮气田在美国独特地质环境之外是否也有发现还需要进一步的研究。富氦二氧化碳气田中的氦主要也来自壳源且产量可观。科罗拉多高原上的富氦二氧化碳气田均被认为是来源于新生代晚期的岩浆活动,且该地区岩浆岩具有较高的U、Th含量。地下水溶气脱气-再溶解(Groundwater Gas Stripping and Re-dissolution,GGS-R)模型被普遍认为可以合理解释CO_(2)气藏中氮气、氦等惰性气体的聚集成藏机制。具体来说,幔源CO_(2)载体气充注时将溶解在地下水中的大气源惰性气体与壳源惰性气体脱出成藏,并与地下水达到水/气溶解平衡。虽然不同气田的平衡值各有不同,但是科罗拉多高原上的各气田均显示出相似的范围值,即在相应的储层压力和温度下为0~100 cm^(3)水/cm^(3)气。本文系统分析美国无机成因富氦气藏的氦气生成、运移和聚集机制,讨论氦气在经历氦源岩内游离相扩散初次运移后通过水溶相、气容相集流或是多相渗流方式进行的二次运移及由无机成因载体气N_(2)和CO_(2)共同参与的富集成藏机制,既可为我国氦气勘查提供理论认识依据,也可为二氧化碳地质评价和开发利用及安全封存提供参考。展开更多
The conversion of CO2 into H+ and is a relatively slow reaction. Hence, its kinetics may be rate determining in carbonate rock dissolution. Carbonic anhydrase (CA), which is widespread in nature, was used to catalyze ...The conversion of CO2 into H+ and is a relatively slow reaction. Hence, its kinetics may be rate determining in carbonate rock dissolution. Carbonic anhydrase (CA), which is widespread in nature, was used to catalyze the CO2 conversion process in dissolution experiments of limestone and dolomite. It was found that the rate of dissolution increases by a factor of about 10 after the addition of CA at a high CO2 partial pressure (Pco2) for limestone and about 3 at low Pco2 for dolomite. This shows that reappraisal is necessary for the importance of chemical weathering (including carbonate rock dissolution and silicate weathering) in the atmospheric CO2 sink and the mysterious missing sink in carbon cycling. It is doubtless that previous studies of weathering underestimated weathering rates due to the ignorance of CA as an activator in weathering, thus the contribution of weathering to the atmospheric CO2 sink is also underestimated. This finding also shows the need to examine the situ distribution and activity of CA in different waters and to investigate the role of CA in weathering.展开更多
At a rice wheat rotational free air CO 2 enrichment(FACE) platform, the effect of elevated atmospheric CO 2 on soil nematode communities in a farmland ecosystem was studied. Wheat plots were exposed to elevated atmosp...At a rice wheat rotational free air CO 2 enrichment(FACE) platform, the effect of elevated atmospheric CO 2 on soil nematode communities in a farmland ecosystem was studied. Wheat plots were exposed to elevated atmospheric CO 2(ambient 370 μl/L + 200 μl/L). 32 families and 40 genera of nematode were observed in soil suspensions during the study period. Under FACE treatment, the numbers of total nematodes, bacterivores and fungivores exhibited an increasing trend. Because of the seasonal variation of soil temperature and moisture, the effect of elevated atmospheric CO 2 on soil nematodes was only observed under favorable conditions. The response of nematode communities to elevated atmospheric CO 2 may indicate the change of soil food web.展开更多
The increase of atmospheric carbon dioxide（CO_2） concentration adversely affect several quality traits of rice grains, but the biochemical mechanism remains unclear. The objectives of this study were to determine ho...The increase of atmospheric carbon dioxide（CO_2） concentration adversely affect several quality traits of rice grains, but the biochemical mechanism remains unclear. The objectives of this study were to determine how changes in the source-sink relationship affected rice quality. Source-sink manipulation was achieved by free-air CO_2 enrichment from tillering to maturity and partial removal of spikelet at anthesis using a japonica rice cultivar Wuyunjing 23. Enrichment with CO_2 decreased the head rice percentage and protein concentration of milled rice, but increased the grain chalkiness. In contrast, spikelet removal resulted in a dramatic increase in the head rice percentage and protein concentration, and much less grain chalkiness. Neither CO_2 enrichment nor spikelet removal affected the starch content, but the distribution of starch granule size showed distinct treatment effects. O n average, spikelet removal decreased the percentage of starch granules of diameter 〉10 and 5–10 μm by 23.6 and 5.6%, respectively, and increased those with a diameter of 2–5 and 〈2 μm by 4.6 and 3.3%, respectively. In contrast, CO_2 elevation showed an opposite response： increasing the proportion of large starch granules（〉5 μm） and decreasing that of 〈5 μm. The starch pasting properties were affected by spikelet removal much more than by CO_2 elevation. These results indicated that the protein concentration and starch granule size played a role in chalkiness formation under these experimental conditions.展开更多
Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure(0.1 MPa)without any solvent and co-...Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure(0.1 MPa)without any solvent and co-catalyst leading to 96.1%product yield.It can be reused five times to keep the product yield over 90%.These intriguing results are attributed to a new reaction mechanism,which is supported by theoretical calculations along with the measurements of ^(13)C NMR spectrum and Fourier transform infrared spectroscopy(FT-IR).The excellent catalytic activity can be traced to a CO_(2)-philic group along with an electrophilic hydrogen atom.Our work shows that incorporation of CO_(2)-philic group is an feasible pathway to develop the new efficient ionic liquids.展开更多
基金the National Key Research and Development Program of China(Grant No.2022YFE0106500)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2022076)+1 种基金the National Key Scientific and Technological Infrastructure project“Earth System Numerical Simulation Facility”(EarthLab2023-EL-ZD-00012)。
文摘The atmospheric carbon dioxide(CO_(2))concentration has been increasing rapidly since the Industrial Revolution,which has led to unequivocal global warming and crucial environmental change.It is extremely important to investigate the interactions among atmospheric CO_(2),the physical climate system,and the carbon cycle of the underlying surface for a better understanding of the Earth system.Earth system models are widely used to investigate these interactions via coupled carbon-climate simulations.The Chinese Academy of Sciences Earth System Model version 2(CAS-ESM2.0)has successfully fixed a two-way coupling of atmospheric CO_(2)with the climate and carbon cycle on land and in the ocean.Using CAS-ESM2.0,we conducted a coupled carbon-climate simulation by following the CMIP6 proposal of a historical emissions-driven experiment.This paper examines the modeled CO_(2)by comparison with observed CO_(2)at the sites of Mauna Loa and Barrow,and the Greenhouse Gases Observing Satellite(GOSAT)CO_(2)product.The results showed that CAS-ESM2.0 agrees very well with observations in reproducing the increasing trend of annual CO_(2)during the period 1850-2014,and in capturing the seasonal cycle of CO_(2)at the two baseline sites,as well as over northern high latitudes.These agreements illustrate a good ability of CAS-ESM2.0 in simulating carbon-climate interactions,even though uncertainties remain in the processes involved.This paper reports an important stage of the development of CAS-ESM with the coupling of carbon and climate,which will provide significant scientific support for climate research and China’s goal of carbon neutrality.
文摘The biomass and ratio of root-shoot of Pinus sylvestfthermis seedlings at Co, concentration of 700 μL L-1 and 50 μL-1L-1 were measured using open-top chambers (OTCs) in Changbai Mountain during Jun. to oct. in 1999. The results showed that doubling CO2 concentration was benefit tb seedling growth of the species (500 μL- L1 was better than 700 μLL’ L-1 ) and the biomass production was increased in both aboveground and underground parts of seedlings. Carbon trans formation to roots was evident as rising of CO2 concentration.
文摘Reactions between CH_4 and CO_2 under the action of continuous microwave discharge at atmospheric pressure were studied in a special homemade reactor. The main products were CO and H2, while acetylene and ethylene were also found in the products. Experimental results show that conversions of CH4 and CO2 could be higher than 90% without the presence of any catalyst. Effects of CO2/CH4 molar ratio and total flow rate of the feed gas on the reaction were also investigated.
文摘The CO_2 in the atmosphere is in contact with water vapor and rain droplets forming CO_2·H_2O, HCO -_3 and CO 2- _3. Global precipitation is about 505×10 15 kg/a. Based on theoretical calculation for unpolluted air and measurement observations, we estimated that 100—270×10 12 gC/a are scavenged from the air by global precipitation. This roughly equals carbon emissions from volcanic sources or 2—6 per cent of current CO_2 emissions. An inventory-based estimate on carbon removal in northwestern Europe supports the above calculation on global scale. With increasing CO_2 concentration in the air, precipitation scavenging may increase.
基金supported by the National Natural Science Foundation of China(Grant No.42230608)the UK-China Research&Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP)China as part of the Newton Fund.
文摘This paper provides a systematic evaluation of the ability of 12 Earth System Models(ESMs)participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)to simulate the spatial inhomogeneity of the atmospheric carbon dioxide(CO_(2))concentration.The multi-model ensemble mean(MME)can reasonably simulate the increasing trend of CO_(2) concentration from 1850 to 2014,compared with the observation data from the Scripps CO_(2) Program and CMIP6 prescribed data,and improves upon the CMIP5 MME CO_(2) concentration(which is overestimated after 1950).The growth rate of CO_(2) concentration in the northern hemisphere(NH)is higher than that in the southern hemisphere(SH),with the highest growth rate in the mid-latitudes of the NH.The MME can also reasonably simulate the seasonal amplitude of CO_(2) concentration,which is larger in the NH than in the SH and grows in amplitude after the 1950s(especially in the NH).Although the results of the MME are reasonable,there is a large spread among ESMs,and the difference between the ESMs increases with time.The MME results show that regions with relatively large CO_(2) concentrations(such as northern Russia,eastern China,Southeast Asia,the eastern United States,northern South America,and southern Africa)have greater seasonal variability and also exhibit a larger inter-model spread.Compared with CMIP5,the CMIP6 MME simulates an average spatial distribution of CO_(2) concentration that is much closer to the site observations,but the CMIP6-inter-model spread is larger.The inter-model differences of the annual means and seasonal cycles of atmospheric CO_(2) concentration are both attributed to the differences in natural sources and sinks of CO_(2) between the simulations.
文摘美国广泛发育具有经济效益的富氦无机成因天然气田,如其中富氦氮气田甚至可以含有高达10%的氦。原地和周边地区的基底提供充足的氦源而氮气可来自不同圈层,且通常N_(2)/He(He>0.1%)在5~50之间。但是富氦氮气田在美国独特地质环境之外是否也有发现还需要进一步的研究。富氦二氧化碳气田中的氦主要也来自壳源且产量可观。科罗拉多高原上的富氦二氧化碳气田均被认为是来源于新生代晚期的岩浆活动,且该地区岩浆岩具有较高的U、Th含量。地下水溶气脱气-再溶解(Groundwater Gas Stripping and Re-dissolution,GGS-R)模型被普遍认为可以合理解释CO_(2)气藏中氮气、氦等惰性气体的聚集成藏机制。具体来说,幔源CO_(2)载体气充注时将溶解在地下水中的大气源惰性气体与壳源惰性气体脱出成藏,并与地下水达到水/气溶解平衡。虽然不同气田的平衡值各有不同,但是科罗拉多高原上的各气田均显示出相似的范围值,即在相应的储层压力和温度下为0~100 cm^(3)水/cm^(3)气。本文系统分析美国无机成因富氦气藏的氦气生成、运移和聚集机制,讨论氦气在经历氦源岩内游离相扩散初次运移后通过水溶相、气容相集流或是多相渗流方式进行的二次运移及由无机成因载体气N_(2)和CO_(2)共同参与的富集成藏机制,既可为我国氦气勘查提供理论认识依据,也可为二氧化碳地质评价和开发利用及安全封存提供参考。
基金Financial supports for this research was provided by the National Nature Science Foundation of China(Grant 40073026)Ministry of Science and Technology of China(Grant 164)+1 种基金Natural Science Foundation of Guangxi(Grant 9824021)Ministry of Land and Resources of China(Grant 9806)and Bremen University of Germany.
文摘The conversion of CO2 into H+ and is a relatively slow reaction. Hence, its kinetics may be rate determining in carbonate rock dissolution. Carbonic anhydrase (CA), which is widespread in nature, was used to catalyze the CO2 conversion process in dissolution experiments of limestone and dolomite. It was found that the rate of dissolution increases by a factor of about 10 after the addition of CA at a high CO2 partial pressure (Pco2) for limestone and about 3 at low Pco2 for dolomite. This shows that reappraisal is necessary for the importance of chemical weathering (including carbonate rock dissolution and silicate weathering) in the atmospheric CO2 sink and the mysterious missing sink in carbon cycling. It is doubtless that previous studies of weathering underestimated weathering rates due to the ignorance of CA as an activator in weathering, thus the contribution of weathering to the atmospheric CO2 sink is also underestimated. This finding also shows the need to examine the situ distribution and activity of CA in different waters and to investigate the role of CA in weathering.
文摘At a rice wheat rotational free air CO 2 enrichment(FACE) platform, the effect of elevated atmospheric CO 2 on soil nematode communities in a farmland ecosystem was studied. Wheat plots were exposed to elevated atmospheric CO 2(ambient 370 μl/L + 200 μl/L). 32 families and 40 genera of nematode were observed in soil suspensions during the study period. Under FACE treatment, the numbers of total nematodes, bacterivores and fungivores exhibited an increasing trend. Because of the seasonal variation of soil temperature and moisture, the effect of elevated atmospheric CO 2 on soil nematodes was only observed under favorable conditions. The response of nematode communities to elevated atmospheric CO 2 may indicate the change of soil food web.
基金funded jointly by the National Natural Science Foundation of China(31171460,31371563,31571597,31471437,31261140364)the Major Fundamental Research Program of Natural Science Foundation of Jiangsu Higher Education Institutions,China(11KJA210003)+2 种基金the Jiangsu Planned Projects for Postdoctoral Research Funds,China(1501077C)the China Postdoctoral Science Foundation(2015M581870)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘The increase of atmospheric carbon dioxide（CO_2） concentration adversely affect several quality traits of rice grains, but the biochemical mechanism remains unclear. The objectives of this study were to determine how changes in the source-sink relationship affected rice quality. Source-sink manipulation was achieved by free-air CO_2 enrichment from tillering to maturity and partial removal of spikelet at anthesis using a japonica rice cultivar Wuyunjing 23. Enrichment with CO_2 decreased the head rice percentage and protein concentration of milled rice, but increased the grain chalkiness. In contrast, spikelet removal resulted in a dramatic increase in the head rice percentage and protein concentration, and much less grain chalkiness. Neither CO_2 enrichment nor spikelet removal affected the starch content, but the distribution of starch granule size showed distinct treatment effects. O n average, spikelet removal decreased the percentage of starch granules of diameter 〉10 and 5–10 μm by 23.6 and 5.6%, respectively, and increased those with a diameter of 2–5 and 〈2 μm by 4.6 and 3.3%, respectively. In contrast, CO_2 elevation showed an opposite response： increasing the proportion of large starch granules（〉5 μm） and decreasing that of 〈5 μm. The starch pasting properties were affected by spikelet removal much more than by CO_2 elevation. These results indicated that the protein concentration and starch granule size played a role in chalkiness formation under these experimental conditions.
基金supported by the National Natural Science Foundation of China(21975064)Program of Henan Center for Outstanding Overseas Scientists(GZS2020011)+1 种基金Henan University's first-class discipline science and technology research project(2018YLTD07,2018YLZDYJ11,2019YLZDYJ09)the Excellent Foreign Experts Project of Henan University。
文摘Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure(0.1 MPa)without any solvent and co-catalyst leading to 96.1%product yield.It can be reused five times to keep the product yield over 90%.These intriguing results are attributed to a new reaction mechanism,which is supported by theoretical calculations along with the measurements of ^(13)C NMR spectrum and Fourier transform infrared spectroscopy(FT-IR).The excellent catalytic activity can be traced to a CO_(2)-philic group along with an electrophilic hydrogen atom.Our work shows that incorporation of CO_(2)-philic group is an feasible pathway to develop the new efficient ionic liquids.
