Urbanization radically alters the climatic environment and landscape patterns of urban areas,but its impact on the carbon sequestration capacity of vegetation remains uncertain.Given the limitations of current small-s...Urbanization radically alters the climatic environment and landscape patterns of urban areas,but its impact on the carbon sequestration capacity of vegetation remains uncertain.Given the limitations of current small-scale ground-based in situ experiments,the response of vegetation carbon sequestration capacity to urbanization and the factors influencing it remain unclear at the global scale.Using multisource remote sensing data,we quanti-fied and differentiated the direct and indirect impacts of urbanization on the carbon sequestration capacity of vegetation in 508 large urban areas globally from 2000 to 2020.The results revealed that the direct impacts of urbanization were generally negative.However,446 cities experienced an indirect enhancement in vegetation carbon sequestration capacity during urbanization,averaging 19.6%globally and offsetting 14.7%of the di-rect loss due to urbanization.These positive indirect effects were most pronounced in environments with limited hydrothermal conditions and increased most in densely populated temperate and cold regions.Furthermore,indi-rect impacts were closely related to urbanization intensity,human footprint,and level of urban development.Our study enhances the understanding of how the carbon sequestration capacity of vegetation dynamically responds to changes in the urban environment,which is crucial for improving future urban vegetation management and building sustainable cities.展开更多
The purpose of this paper is to study the planning and design of campus plant communities from the perspective of vegetation carbon sink capacity.During the research period,based on literature review and material inve...The purpose of this paper is to study the planning and design of campus plant communities from the perspective of vegetation carbon sink capacity.During the research period,based on literature review and material investigation,the quantitative calculation of the carbon sink capacity of the vegetation of the campus of the case study university was carried out using the i-Tree model,and the shortcomings of the carbon sink level of the campus vegetation community were pointed out based on the calculation results.Subsequently,with the goal of improving the carbon sink capacity,the park is oriented to the planning and design of vegetation communities,and the feasibility of the program is demonstrated with the support of the data on the level of carbon sink capacity after the implementation of the program.It is hoped that this paper can provide technical reference for the managers of universities and urban landscape departments in China,and actively promote the optimization of vegetation communities,enhance the carbon sink capacity,and promote the full implementation of the goal of sustainable development.展开更多
[Objectives]To explore the effects of single application of chemical fertilizers on soil carbon fixation capacity and soil fertility under plastic film mulching conditions in eastern Qinghai,and to provide a theoretic...[Objectives]To explore the effects of single application of chemical fertilizers on soil carbon fixation capacity and soil fertility under plastic film mulching conditions in eastern Qinghai,and to provide a theoretical basis for realizing the sustainable development of film mulching planting method in this area.[Methods]The effects of single application of chemical fertilizer cultivation mode under film mulching conditions on the soil organic carbon(SOC),labile organic carbon(LOC),carbon management index(CMI),extractable humus carbon(CHE),humic acid carbon(CHA),and fulvic acid carbon(CFA)in the cultivated layer(0-20 cm)were studied through three consecutive years of field experiments on dryland maize farmland in the eastern Qinghai.[Results]Under the film mulching condition,the SOC,LOC and CMI of the single application of chemical fertilizer cultivation mode were lower than that of the open field control.CHE,CHA and CFA increased with the increase of planting years,but the degree of increase was generally less than that of the open field control.With the increase of planting years,by 2020,the soil LOC/SOC value of film mulching decreased by 4.97%compared with before the start of the experiment,while the open field control increased by 1.11%;the organic carbon oxidation stability coefficient(KOS)of the film mulching was higher than that of the open field control;the soil CHA/CFA value and PQ value were higher than that of the open field control.[Conclusions]Under the condition of single application of chemical fertilizers,the continuous film mulching cultivation mode reduces the soil carbon fixation capacity,and soil organic carbon tends to be stable,which is not conducive to biological utilization and could reduce the soil fertility and degrade the soil quality,causing adverse effects on the stability of crop yield and sustainable production in the long run.展开更多
On January 19, 2008, the ground breaking ceremony of prebaked anode carbon project with 400 thousand tons annual capacity of Pingguo Haohai Carbon Co. , Ltd was held in Pingguo Industry Zone of Guangxi province. After...On January 19, 2008, the ground breaking ceremony of prebaked anode carbon project with 400 thousand tons annual capacity of Pingguo Haohai Carbon Co. , Ltd was held in Pingguo Industry Zone of Guangxi province. After being put into production, the project with an investment of CNY 0.8 billion, will reach CNY 1.6 billion annual production value.展开更多
This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking an...This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking and neutrality goals.This research ana-lyzes the spatial characteristics of carbon metabolism from 2000 to 2020 and uses models to identify stable carbon sink areas,positive carbon flow corridors,and carbon sequestration nodes.The goal is to construct a carbon metabolism spatial security pattern(CMSSP)and propose territorial ecological restoration strategies under different development demand scenarios.The results show the following:1)in 2020,the study area’s carbon sink decreased by 8.29×10^(4) t C/yr compared with that in 2010 and by 10.83×10^(4) t C/yr compared with that in 2000.High-carbon sinks were found mainly in mountainous areas,whereas low-carbon sinks are concentrated in urban con-struction land,rural residential areas,and land margins.2)From 2000 to 2020,the spatial security pattern of carbon metabolism tended to be‘high in the middle of the east and west and low in the gulf.’In 2000,2010,and 2020,16 stable carbon sinks were identified.The carbon energy flow density in Guangxi was greater than that in Guangdong and Hainan,with positive carbon flow corridors located primarily in Guangxi and Guangdong.The number of carbon sequestration nodes remained stable at approximately 15,mainly in Guangxi and Hainan.3)Scenario simulations revealed that under the Nature-based mild restoration scenario,the carbon sink rate will reach 611.85×10^(4) t C/yr by 2030 and increase to 612.45×10^(4) t C/yr by 2060,with stable carbon sinks increasing to 18.In the restora-tion scenario based on Anti-globalization,the carbon sink will decrease from 610.24×10^(4) t C/yr in 2030 to 605.19×10^(4) t C/yr in 2060,with the disappearance of some positive carbon flow corridors and stable carbon sinks.Under the Human-based sustainable restoration scenario,the carbon sink area will decrease from 607.00×10^(4) t C/yr in 2030 to 596.39×10^(4) t C/yr in 2060,with carbon sink areas frag-menting and positive carbon flow corridors becoming less dense.4)On the basis of the current and predicted CMSSPs,this study ex-plores spatial ecological restoration strategies for high-carbon storage areas in bay urban agglomerations at four levels:the land control region,urban agglomeration structure system,carbon sink structure and bay structure control region.展开更多
Large-scale afforestation and forest conservation policies have been widely implemented in Southwest China over past decades.These efforts have significantly protected the remaining long-established forests in the reg...Large-scale afforestation and forest conservation policies have been widely implemented in Southwest China over past decades.These efforts have significantly protected the remaining long-established forests in the region and greatly expanded forested areas.Utilizing nearly 30 years of satellite time-series data,we reveal that the region’s enhanced carbon sequestration(3×10^(12) g·C annually)is primarily driven by crucial changes in forest structure and age,occurring alongside a nearly 120%increase in forested land area.We observe that dense forests maintain a rapid growth rate of approximately 2.5%annually for carbon sequestration in the initial years after establishment.However,this growth rate decelerates with increasing apparent forest age.Meanwhile,the densification(modeled as an increasing forest probability)rate of forests reaches its peak growth during the 10-20 year period,sustaining a high annual growth rate of about 1.8%.We also find that improvements in forest structure,particularly the increasing of forest canopy density and apparent forest age coupled with a notable reduction in forest fragmentation,are also the main driving factors for the enhanced carbon sequestration capacity.Based on these findings,we conclude that forest restoration policies in Southwest China have been successful not only in facilitating large-scale forest growth in Southwest China but,more critically,in promoting the structural maturation(e.g.,densification and reduced fragmentation)that is essential for enhancing the region’s carbon sink capacity and its resilience.展开更多
AIM： To study the presence of sustained low diffusing capacity （DLco） after liver transplantation （LT） in patients with hepatopulmonary syndrome （HPS）. METHODS： Six patients with mild-to-severe HPS and 24 with...AIM： To study the presence of sustained low diffusing capacity （DLco） after liver transplantation （LT） in patients with hepatopulmonary syndrome （HPS）. METHODS： Six patients with mild-to-severe HPS and 24 without HPS who underwent LT were prospectively followed before and after LT at mid-term （median, 15 mo）. HPS patients were also assessed at Iong-tem （median, 86 mo）. RESULTS： Before LT, HPS patients showed lower PaO2 （71 ± 8 mmHg）, higher AaPO2 （43 ± 10 mmHg） and lower DLco （54% ± 9% predicted）, due to a combination of moderate-to-severe ventilation-perfusion （VA/Q） imbalance, mild shunt and diffusion limitation, than non- HPS patients （94 ± 4 mmHg and 19 ± 3 mmHg, and 85% ± 3% predicted, respectively） （P 〈 0.05 each）. Seven non-HPS patients had also reduced DLco （70% ± 4% predicted）. At mid- and long-term after LT, compared to pre- LT, HPS patients normalized PaO2 （91 ± 3 mmHg and 87 ± 5 mmHg）, AaPO2 （14 ± 3 mmHg and 23 ± 5 mmHg） and all VA/Q descriptors （P 〈 0.05 each） without changes in DLco （53% ± 8% and 56% ± 7% predicted, respectively）. Post-LT DLco in non-HPS patients with pre- LT low DLco was unchanged （75% ± 6% predicted）. CONCLUSION： While complete VA/Q resolution in HPS indicates a reversible functional disturbance, sustained low DLco after LT also present in some non-HPS patients, points to persistence of sub-clinical liver-induced pulmonary vascular changes.展开更多
Facile production of high quality activated carbons from biomass materials has greatly triggered much attention presently. In this paper, a series of interconnected porous carbon materials from lotus root shells bioma...Facile production of high quality activated carbons from biomass materials has greatly triggered much attention presently. In this paper, a series of interconnected porous carbon materials from lotus root shells biomass are prepared via simple pyrolysis and followed by a KOH activation process. The prepared carbons exhibit high specific surface areas of up to 2961 m^2/g and large pore volume～1.47 cm3/g. In addition, the resultant porous carbons served as electrode materials in supercapacitor exhibit high specific capacitance and outstanding recycling stability and high energy density. In particular, their specific capacitance retention was almost 100% after 10500 cycles at a current density of 2 A/g. Remarkabely, the impact of the tailored specific surface areas of various carbon samples on their capacitive performances is systematically investigated.Generally, it was believed that the highly-developed porosity features（including surface areas and pore volume and pore size-distributions）, together with the good conductivity of activated carbon species, play a key role in effectively improving the storage energy performances of the porous carbon electrode materials in supercapacitor.展开更多
The use of sequestered carbon dioxide(CO) as the heat exchange fluid in enhanced geothermal system(EGS) has significant potential to increase their productivity, contribute further to reducing carbon emissions and inc...The use of sequestered carbon dioxide(CO) as the heat exchange fluid in enhanced geothermal system(EGS) has significant potential to increase their productivity, contribute further to reducing carbon emissions and increase the economic viability of geothermal power generation. Coupled COsequestration and geothermal energy production from hot dry rock(HDR) EGS were first proposed 15 years ago but have yet to be practically implemented. This paper reviews some of the issues in assessing these systems with particular focus on the power generation and COsequestration capacity. The Habanero geothermal field in the Cooper Basin of South Australia is assessed for its potential COstorage capacity if supercritical COis used as the working fluid for heat extraction. The analysis suggests that the major COsequestration mechanisms are the storage in the fracture-stimulation damaged zone followed by diffusion into the pores within the rock matrix. The assessment indicates that 5% of working fluid loss commonly suggested as the storage capacity might be an over-estimate of the long-term COsequestration capacity of EGS in which supercritical COis used as the circulation fluid.展开更多
Control of desertification can not only ameliorate the natural environment of arid regions but also convert desertified land into significant terrestrial carbon sinks,thereby bolstering the carbon sequestration capaci...Control of desertification can not only ameliorate the natural environment of arid regions but also convert desertified land into significant terrestrial carbon sinks,thereby bolstering the carbon sequestration capacity of arid ecosystems.However,longstanding neglect of the potential carbon sink benefits of desertification management,and its relationship with environmental factors,has limited the exploration of carbon sequestration potential.Based on CO_(2) flux and environmental factors of artificial protective forest in the Taklamakan Desert from 2018 to 2019,we found that the carbon storage capacity of the desert ecosystem increased approximately 140-fold after the establishment of an artificial shelter forest in the desert,due to plant photosynthesis.Precipitation levels less than 2 mm had no impact on carbon exchange in the artificial shelter forest,whereas a precipitation level of approximately 4 mm stimulated a decrease in the vapor pressure deficit over a short period of about three days,promoting photosynthesis and enhancing the carbon absorption of the artificial shelter forest.Precipitation events greater than 8 mm stimulated soil respiration to release CO_(2) and promoted plant photosynthesis.In the dynamic equilibrium where precipitation stimulates both soil respiration and photosynthesis,there is a significant threshold value of soil moisture at 5 cm(0.12 m^(3) m^(-3)),which can serve as a good indicator of the strength of the stimulatory effect of precipitation on both.These results provide important data support for quantifying the contribution of artificial afforestation to carbon sequestration in arid areas,and provide guidance for the development and implementation of artificial forest management measures.展开更多
Synergistic carbon emission reduction at the urban scale is an inherent requirement for China to realize its carbon emission reduction commitments and promote sustainable and regional synergistic development.Using 16 ...Synergistic carbon emission reduction at the urban scale is an inherent requirement for China to realize its carbon emission reduction commitments and promote sustainable and regional synergistic development.Using 16 prefectural cities in Shandong Province as an example,this study defines and quantifies the regional carbon emission reduction capacity(CERC)based on the synergistic development of carbon emission reduction,environmental protection,and economic growth objectives.The spatial network characteristics of the(CERC)and its drivers were analyzed using social network analysis and quadratic assignment procedure regression methods.The results revealed that the spatial correlation of the CERC among prefectural cities has been increasing over the years.Jinan−Zibo−Qingdao is the center of the network,while the spatial linkage strength in the southwest and northeast of Shandong Province is weak.Geospatial distance and scientific development differences have a significant negative effect on the intensity of spatial association,while differences in economic and informatization developments have a considerable positive impact.Environmental regulatory differences and transportation differences are not significant.This study offers a methodological reference for similar studies in other countries or regions.At the same time,the findings provide a scientific basis for the government to rationally allocate urban resources and promote regional synergistic carbon emission reduction.展开更多
As the integration point of urban blue-green spaces,wetland parks play an important role in the construction of urban carbon pools.It is of great significance for achieving carbon neutrality and peak carbon emissions ...As the integration point of urban blue-green spaces,wetland parks play an important role in the construction of urban carbon pools.It is of great significance for achieving carbon neutrality and peak carbon emissions by reasonably evaluating the carbon sequestration capacity of wetland parks and optimizing wetland structure.In this paper,Guangzhou wetland park is taken as the research object.Through field research,the carbon sequestration potential of ecosystems at multiple levels,including forest vegetation,seedlings,and wetland ecosystems is studied,and policy recommendations are put forward for carbon sequestration in wetland systems.The results show that the annual carbon sequestration capacity of the wetland is 1296.59 t,and the annual net carbon sequestration value is 100485 yuan.Among the three regions,proportions of annual carbon sequestration of the forest vegetation plate,seedling plate,and wetland ecosystem plate account for 28.4%,41.3%,and 30.3%,respectively.展开更多
Soil organic carbon (SOC) retaining capacities of epipedon (EP), subsoil (SS) and soil cover (SC) as a whole, are soil type specific. Depending on individual and sites characteristics, the generalized humus status ind...Soil organic carbon (SOC) retaining capacities of epipedon (EP), subsoil (SS) and soil cover (SC) as a whole, are soil type specific. Depending on individual and sites characteristics, the generalized humus status indices of soil types (EP and SC thickness and SOC stocks) may vary. Land use and land use change primarily influence the properties and fabric of the EP, but the humus status (SOC concentration and stock, fabric of horizons) of the SS remains practically unchangeable. The mean mineral soils SOC stocks, EP quality and SOC distribution in soil profiles depend mainly on the water regime, mineral composition (texture, calcareousness), development of eluvial processes and the land use peculiarities of soils. The mean area weighted SC SOC stock of Estonian mineral soils is 99.9 Mg ha–1, thereby the mean hydromorphic soils SOC retention capacity considerably exceeds the SOC retention capacity of automorphic soils (means are accordingly 127.5 and 78.9 Mg ha–1). The sustainable management of SOC is based on adequate information about actual SOC stocks and theoretically established or optimal humus status levels of soil types. The aggregate of SOC retained in the mineral soils of Estonia (3,235,100 ha) amounts to 323 ± 46 Tg (1 Tg = 1012 g). Approximately 42% of this is sequestered into stabilized humus, 40% into instable raw-humous material and 18% into forest (grassland) floor and shallow peat layers.展开更多
Forests play an important role in acting as a carbon sink of terrestrial ecosystem.Although global forests have huge carbon carrying capacity(CCC)and carbon sequestration potential(CSP),there were few quantification r...Forests play an important role in acting as a carbon sink of terrestrial ecosystem.Although global forests have huge carbon carrying capacity(CCC)and carbon sequestration potential(CSP),there were few quantification reports on Chinese forests.We collected and compiled a forest biomass dataset of China,a total of 5841 sites,based on forest inventory and literature search results.From the dataset we extracted 338 sites with forests aged over 80 years,a threshold for defining mature forest,to establish the mature forest biomass dataset.After analyzing the spatial pattern of the carbon density of Chinese mature forests and its controlling factors,we used carbon density of mature forests as the reference level,and conservatively estimated the CCC of the forests in China by interpolation methods of Regression Kriging,Inverse Distance Weighted and Partial Thin Plate Smoothing Spline.Combining with the sixth National Forest Resources Inventory,we also estimated the forest CSP.The results revealed positive relationships between carbon density of mature forests and temperature,precipitation and stand age,and the horizontal and elevational patterns of carbon density of mature forests can be well predicted by temperature and precipitation.The total CCC and CSP of the existing forests are 19.87 and 13.86 Pg C,respectively.Subtropical forests would have more CCC and CSP than other biomes.Consequently,relying on forests to uptake carbon by decreasing disturbance on forests would be an alternative approach for mitigating greenhouse gas concentration effects besides afforestation and reforestation.展开更多
Mangrove restoration is recognized as an effective strategy for enhancing the carbon storage capacity of natural ecosystems,advancing toward the“carbon neutrality”goal.The carbon storage effects of ecological restor...Mangrove restoration is recognized as an effective strategy for enhancing the carbon storage capacity of natural ecosystems,advancing toward the“carbon neutrality”goal.The carbon storage effects of ecological restoration efforts remain insufficiently understood as previous studies have focused on carbon storage dynamics in ecosystems,yet the specific impacts of targeted mangrove restoration are less explored.This study utilizes multi-temporal remote sensing data and actual restoration data from Dongzhai Harbor Hainan Island to identify the mangrove wetland coverage and quantify the spatiotemporal evolution of carbon storage under various restoration efforts using the InVEST model.Additionally,we employed the PLUS model to simulate and compare carbon storage potential under multiple development goals.The findings reveal the following:(a)Mangrove restoration significantly increased the area of land with high carbon sink capability,resulting in a regional carbon storage increase of 210,001.68 tons from 2015 to 2021,with 97%of this increase attributable to ecological restoration.(b)Mangrove coverage is crucial for regional carbon storage,with an average of 443 tons of carbon stored per hectare.Decreases in carbon storage occurred mainly during the conversion of mangroves to aquaculture,and forests/agriculture to residential areas.Increases in carbon storage were seen in the reverse transitions.(c)Comparing the scenarios focused solely on mangrove protection with cultivated land protection,the carbon storage in Dongzhai Harbor is projected to reach its maximum by 2045 under the carbon storage priority scenario.Our findings build a scientific foundation for formulating effective mangrove conservation and restoration strategies.展开更多
Background： Pulmonary alveolar proteinosis （PAP） is a rare lung disease, the most common type of which is autoimmune PAP. The gold standard therapy for PAP is whole lung lavage （WLL）. Few studies have reported th...Background： Pulmonary alveolar proteinosis （PAP） is a rare lung disease, the most common type of which is autoimmune PAP. The gold standard therapy for PAP is whole lung lavage （WLL）. Few studies have reported the optimal technique with which to evaluate the response to WLL. In this study, we aimed to identify parameters with which to assess the need for repeat WLL during a long-term 8-year follow-up. Methods： We conducted a retrospective analysis of 120 patients with autoimmune PAP with 80 of whom underwent WLL. Physiologic, serologic, and radiologic features of the patients were analyzed during an 8-year follow-up after the first WLL treatment. Results： Of the 40 patients without any intervention, 39 patients either achieved remission or remained stable and only one died of pulmonary infection. Of the 56 patients who underwent WLL for 1 time, 55 remained free from a second WLL and 1 patient died of cancer. Twenty-four required additional treatments after their first WLL. The baseline PaO2, （P = 0.000）, PA-aO2 （P = 0.000）, shunt fraction rate （P = 0.001）, percent of predicted normal diffusing capacity of the lung for carbon monoxide （DLCO%Pred） （P = 0.016）, 6-rain walk test （P = 0.013）, carcinoembryonic antigen （CEA） （P = 0.007）, and neuron-specific enolase （NSE） （P = 0.003） showed significant differences among the three groups. The need for a second WLL was significantly associated with PaO2 （P = 0.000）, CEA （P= 0.050）, the 6-minute walk test （P= 0.026）, and DLCO%Pred （P = 0.041 ）. The DLCO%Pred on admission with a cut-off value of42.1% （P = 0.001） may help to distinguish whether patients with PAP require a second WLL. Conclusions： WLL is the optimal treatment method for PAP and provides remarkable improvements for affected patients. The DLCO%Pred on admission with a cut-offvalue of 42.1% may distinguish whether patients with PAP require a second WLL.展开更多
基金supported by the National Natural Science Foun-dation of China(Grants No.42471118 and 52078440)the Youth Innovation Promotion Association of CAS(Grant No.2021194).
文摘Urbanization radically alters the climatic environment and landscape patterns of urban areas,but its impact on the carbon sequestration capacity of vegetation remains uncertain.Given the limitations of current small-scale ground-based in situ experiments,the response of vegetation carbon sequestration capacity to urbanization and the factors influencing it remain unclear at the global scale.Using multisource remote sensing data,we quanti-fied and differentiated the direct and indirect impacts of urbanization on the carbon sequestration capacity of vegetation in 508 large urban areas globally from 2000 to 2020.The results revealed that the direct impacts of urbanization were generally negative.However,446 cities experienced an indirect enhancement in vegetation carbon sequestration capacity during urbanization,averaging 19.6%globally and offsetting 14.7%of the di-rect loss due to urbanization.These positive indirect effects were most pronounced in environments with limited hydrothermal conditions and increased most in densely populated temperate and cold regions.Furthermore,indi-rect impacts were closely related to urbanization intensity,human footprint,and level of urban development.Our study enhances the understanding of how the carbon sequestration capacity of vegetation dynamically responds to changes in the urban environment,which is crucial for improving future urban vegetation management and building sustainable cities.
基金Chongqing Municipal Education Commission Science and Technology Research ProjectResearch on Zero-Emission Campus Construction Based on Plant Community Optimization(Project No.KJQN202305605)。
文摘The purpose of this paper is to study the planning and design of campus plant communities from the perspective of vegetation carbon sink capacity.During the research period,based on literature review and material investigation,the quantitative calculation of the carbon sink capacity of the vegetation of the campus of the case study university was carried out using the i-Tree model,and the shortcomings of the carbon sink level of the campus vegetation community were pointed out based on the calculation results.Subsequently,with the goal of improving the carbon sink capacity,the park is oriented to the planning and design of vegetation communities,and the feasibility of the program is demonstrated with the support of the data on the level of carbon sink capacity after the implementation of the program.It is hoped that this paper can provide technical reference for the managers of universities and urban landscape departments in China,and actively promote the optimization of vegetation communities,enhance the carbon sink capacity,and promote the full implementation of the goal of sustainable development.
基金Project of Natural Science Foundation of Qinghai Province(2018-ZJ-724)Major Science and Technology Program of Qinghai Province(2019-NK-A11).
文摘[Objectives]To explore the effects of single application of chemical fertilizers on soil carbon fixation capacity and soil fertility under plastic film mulching conditions in eastern Qinghai,and to provide a theoretical basis for realizing the sustainable development of film mulching planting method in this area.[Methods]The effects of single application of chemical fertilizer cultivation mode under film mulching conditions on the soil organic carbon(SOC),labile organic carbon(LOC),carbon management index(CMI),extractable humus carbon(CHE),humic acid carbon(CHA),and fulvic acid carbon(CFA)in the cultivated layer(0-20 cm)were studied through three consecutive years of field experiments on dryland maize farmland in the eastern Qinghai.[Results]Under the film mulching condition,the SOC,LOC and CMI of the single application of chemical fertilizer cultivation mode were lower than that of the open field control.CHE,CHA and CFA increased with the increase of planting years,but the degree of increase was generally less than that of the open field control.With the increase of planting years,by 2020,the soil LOC/SOC value of film mulching decreased by 4.97%compared with before the start of the experiment,while the open field control increased by 1.11%;the organic carbon oxidation stability coefficient(KOS)of the film mulching was higher than that of the open field control;the soil CHA/CFA value and PQ value were higher than that of the open field control.[Conclusions]Under the condition of single application of chemical fertilizers,the continuous film mulching cultivation mode reduces the soil carbon fixation capacity,and soil organic carbon tends to be stable,which is not conducive to biological utilization and could reduce the soil fertility and degrade the soil quality,causing adverse effects on the stability of crop yield and sustainable production in the long run.
文摘On January 19, 2008, the ground breaking ceremony of prebaked anode carbon project with 400 thousand tons annual capacity of Pingguo Haohai Carbon Co. , Ltd was held in Pingguo Industry Zone of Guangxi province. After being put into production, the project with an investment of CNY 0.8 billion, will reach CNY 1.6 billion annual production value.
基金Under the auspices of the National Natural Science Foundation of China(No.52268008)。
文摘This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking and neutrality goals.This research ana-lyzes the spatial characteristics of carbon metabolism from 2000 to 2020 and uses models to identify stable carbon sink areas,positive carbon flow corridors,and carbon sequestration nodes.The goal is to construct a carbon metabolism spatial security pattern(CMSSP)and propose territorial ecological restoration strategies under different development demand scenarios.The results show the following:1)in 2020,the study area’s carbon sink decreased by 8.29×10^(4) t C/yr compared with that in 2010 and by 10.83×10^(4) t C/yr compared with that in 2000.High-carbon sinks were found mainly in mountainous areas,whereas low-carbon sinks are concentrated in urban con-struction land,rural residential areas,and land margins.2)From 2000 to 2020,the spatial security pattern of carbon metabolism tended to be‘high in the middle of the east and west and low in the gulf.’In 2000,2010,and 2020,16 stable carbon sinks were identified.The carbon energy flow density in Guangxi was greater than that in Guangdong and Hainan,with positive carbon flow corridors located primarily in Guangxi and Guangdong.The number of carbon sequestration nodes remained stable at approximately 15,mainly in Guangxi and Hainan.3)Scenario simulations revealed that under the Nature-based mild restoration scenario,the carbon sink rate will reach 611.85×10^(4) t C/yr by 2030 and increase to 612.45×10^(4) t C/yr by 2060,with stable carbon sinks increasing to 18.In the restora-tion scenario based on Anti-globalization,the carbon sink will decrease from 610.24×10^(4) t C/yr in 2030 to 605.19×10^(4) t C/yr in 2060,with the disappearance of some positive carbon flow corridors and stable carbon sinks.Under the Human-based sustainable restoration scenario,the carbon sink area will decrease from 607.00×10^(4) t C/yr in 2030 to 596.39×10^(4) t C/yr in 2060,with carbon sink areas frag-menting and positive carbon flow corridors becoming less dense.4)On the basis of the current and predicted CMSSPs,this study ex-plores spatial ecological restoration strategies for high-carbon storage areas in bay urban agglomerations at four levels:the land control region,urban agglomeration structure system,carbon sink structure and bay structure control region.
基金funded by the National Natural Science Foundation of China(Grant No.42377331)supported by the U.S.National Science Foundation Division of Environmental Biology award#2331162U.S.National Science Foundation Dynamics of Integrated Socio-Environmental Systems award#2408954.
文摘Large-scale afforestation and forest conservation policies have been widely implemented in Southwest China over past decades.These efforts have significantly protected the remaining long-established forests in the region and greatly expanded forested areas.Utilizing nearly 30 years of satellite time-series data,we reveal that the region’s enhanced carbon sequestration(3×10^(12) g·C annually)is primarily driven by crucial changes in forest structure and age,occurring alongside a nearly 120%increase in forested land area.We observe that dense forests maintain a rapid growth rate of approximately 2.5%annually for carbon sequestration in the initial years after establishment.However,this growth rate decelerates with increasing apparent forest age.Meanwhile,the densification(modeled as an increasing forest probability)rate of forests reaches its peak growth during the 10-20 year period,sustaining a high annual growth rate of about 1.8%.We also find that improvements in forest structure,particularly the increasing of forest canopy density and apparent forest age coupled with a notable reduction in forest fragmentation,are also the main driving factors for the enhanced carbon sequestration capacity.Based on these findings,we conclude that forest restoration policies in Southwest China have been successful not only in facilitating large-scale forest growth in Southwest China but,more critically,in promoting the structural maturation(e.g.,densification and reduced fragmentation)that is essential for enhancing the region’s carbon sink capacity and its resilience.
基金Supported by Red Respira-ISCIII-RTIC-03/11 and Generalitat de Catalunya, No. 2005SGR-00822
文摘AIM： To study the presence of sustained low diffusing capacity （DLco） after liver transplantation （LT） in patients with hepatopulmonary syndrome （HPS）. METHODS： Six patients with mild-to-severe HPS and 24 without HPS who underwent LT were prospectively followed before and after LT at mid-term （median, 15 mo）. HPS patients were also assessed at Iong-tem （median, 86 mo）. RESULTS： Before LT, HPS patients showed lower PaO2 （71 ± 8 mmHg）, higher AaPO2 （43 ± 10 mmHg） and lower DLco （54% ± 9% predicted）, due to a combination of moderate-to-severe ventilation-perfusion （VA/Q） imbalance, mild shunt and diffusion limitation, than non- HPS patients （94 ± 4 mmHg and 19 ± 3 mmHg, and 85% ± 3% predicted, respectively） （P 〈 0.05 each）. Seven non-HPS patients had also reduced DLco （70% ± 4% predicted）. At mid- and long-term after LT, compared to pre- LT, HPS patients normalized PaO2 （91 ± 3 mmHg and 87 ± 5 mmHg）, AaPO2 （14 ± 3 mmHg and 23 ± 5 mmHg） and all VA/Q descriptors （P 〈 0.05 each） without changes in DLco （53% ± 8% and 56% ± 7% predicted, respectively）. Post-LT DLco in non-HPS patients with pre- LT low DLco was unchanged （75% ± 6% predicted）. CONCLUSION： While complete VA/Q resolution in HPS indicates a reversible functional disturbance, sustained low DLco after LT also present in some non-HPS patients, points to persistence of sub-clinical liver-induced pulmonary vascular changes.
基金National Science Foundation of China(No.21173167)the Science and Technology Committee of Shaanxi Province(Grant No.2014KW09-03)+1 种基金Program for New Century Excellent Talents in University(NCET-13-0953)the Research Fund of the State Key Lab of Solidification Processing(NWPU),China(Grant No.15-BZ-2015)
文摘Facile production of high quality activated carbons from biomass materials has greatly triggered much attention presently. In this paper, a series of interconnected porous carbon materials from lotus root shells biomass are prepared via simple pyrolysis and followed by a KOH activation process. The prepared carbons exhibit high specific surface areas of up to 2961 m^2/g and large pore volume～1.47 cm3/g. In addition, the resultant porous carbons served as electrode materials in supercapacitor exhibit high specific capacitance and outstanding recycling stability and high energy density. In particular, their specific capacitance retention was almost 100% after 10500 cycles at a current density of 2 A/g. Remarkabely, the impact of the tailored specific surface areas of various carbon samples on their capacitive performances is systematically investigated.Generally, it was believed that the highly-developed porosity features（including surface areas and pore volume and pore size-distributions）, together with the good conductivity of activated carbon species, play a key role in effectively improving the storage energy performances of the porous carbon electrode materials in supercapacitor.
基金funded by Australian Research Council Discovery Project(Grant No.DP110104766)financial support from the China Australia Geological Storage of CO_2 Project(CAGS)Australia-China Young Researchers Exchange Program 2012
文摘The use of sequestered carbon dioxide(CO) as the heat exchange fluid in enhanced geothermal system(EGS) has significant potential to increase their productivity, contribute further to reducing carbon emissions and increase the economic viability of geothermal power generation. Coupled COsequestration and geothermal energy production from hot dry rock(HDR) EGS were first proposed 15 years ago but have yet to be practically implemented. This paper reviews some of the issues in assessing these systems with particular focus on the power generation and COsequestration capacity. The Habanero geothermal field in the Cooper Basin of South Australia is assessed for its potential COstorage capacity if supercritical COis used as the working fluid for heat extraction. The analysis suggests that the major COsequestration mechanisms are the storage in the fracture-stimulation damaged zone followed by diffusion into the pores within the rock matrix. The assessment indicates that 5% of working fluid loss commonly suggested as the storage capacity might be an over-estimate of the long-term COsequestration capacity of EGS in which supercritical COis used as the circulation fluid.
基金jointly supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(Grant No.2022D01E104)the National Natural Science Foundation General Project(Grant No.41975010)+1 种基金the China Post doctoral Science Foundation(Grant No.2022MD723851)the Scientific and Technological Innovation Team(Tianshan Innovation Team)project(Grant No.2022TSYCTD0007).
文摘Control of desertification can not only ameliorate the natural environment of arid regions but also convert desertified land into significant terrestrial carbon sinks,thereby bolstering the carbon sequestration capacity of arid ecosystems.However,longstanding neglect of the potential carbon sink benefits of desertification management,and its relationship with environmental factors,has limited the exploration of carbon sequestration potential.Based on CO_(2) flux and environmental factors of artificial protective forest in the Taklamakan Desert from 2018 to 2019,we found that the carbon storage capacity of the desert ecosystem increased approximately 140-fold after the establishment of an artificial shelter forest in the desert,due to plant photosynthesis.Precipitation levels less than 2 mm had no impact on carbon exchange in the artificial shelter forest,whereas a precipitation level of approximately 4 mm stimulated a decrease in the vapor pressure deficit over a short period of about three days,promoting photosynthesis and enhancing the carbon absorption of the artificial shelter forest.Precipitation events greater than 8 mm stimulated soil respiration to release CO_(2) and promoted plant photosynthesis.In the dynamic equilibrium where precipitation stimulates both soil respiration and photosynthesis,there is a significant threshold value of soil moisture at 5 cm(0.12 m^(3) m^(-3)),which can serve as a good indicator of the strength of the stimulatory effect of precipitation on both.These results provide important data support for quantifying the contribution of artificial afforestation to carbon sequestration in arid areas,and provide guidance for the development and implementation of artificial forest management measures.
基金supported by the Department of Science and Technology of Shandong Province [Grant No.2021SFGC0904-05]Shandong Natural Science Foundation [Grant No.ZR2023MD079]+3 种基金Shandong Province Social Science Planning Research Project [Grant No.22CKRJ04]Taishan Scholar Project [Grant No.tsqn202103010]Zaozhuang Science and Technology Bureau [Grant No.2021GH22]the Key R&D Program of Shandong Province,China [Grant No.2023SFGC0101].
文摘Synergistic carbon emission reduction at the urban scale is an inherent requirement for China to realize its carbon emission reduction commitments and promote sustainable and regional synergistic development.Using 16 prefectural cities in Shandong Province as an example,this study defines and quantifies the regional carbon emission reduction capacity(CERC)based on the synergistic development of carbon emission reduction,environmental protection,and economic growth objectives.The spatial network characteristics of the(CERC)and its drivers were analyzed using social network analysis and quadratic assignment procedure regression methods.The results revealed that the spatial correlation of the CERC among prefectural cities has been increasing over the years.Jinan−Zibo−Qingdao is the center of the network,while the spatial linkage strength in the southwest and northeast of Shandong Province is weak.Geospatial distance and scientific development differences have a significant negative effect on the intensity of spatial association,while differences in economic and informatization developments have a considerable positive impact.Environmental regulatory differences and transportation differences are not significant.This study offers a methodological reference for similar studies in other countries or regions.At the same time,the findings provide a scientific basis for the government to rationally allocate urban resources and promote regional synergistic carbon emission reduction.
文摘As the integration point of urban blue-green spaces,wetland parks play an important role in the construction of urban carbon pools.It is of great significance for achieving carbon neutrality and peak carbon emissions by reasonably evaluating the carbon sequestration capacity of wetland parks and optimizing wetland structure.In this paper,Guangzhou wetland park is taken as the research object.Through field research,the carbon sequestration potential of ecosystems at multiple levels,including forest vegetation,seedlings,and wetland ecosystems is studied,and policy recommendations are put forward for carbon sequestration in wetland systems.The results show that the annual carbon sequestration capacity of the wetland is 1296.59 t,and the annual net carbon sequestration value is 100485 yuan.Among the three regions,proportions of annual carbon sequestration of the forest vegetation plate,seedling plate,and wetland ecosystem plate account for 28.4%,41.3%,and 30.3%,respectively.
基金Funding for the research was provided by the Estonian Ministry of Education and Research(Project No.0172613AGML03).
文摘Soil organic carbon (SOC) retaining capacities of epipedon (EP), subsoil (SS) and soil cover (SC) as a whole, are soil type specific. Depending on individual and sites characteristics, the generalized humus status indices of soil types (EP and SC thickness and SOC stocks) may vary. Land use and land use change primarily influence the properties and fabric of the EP, but the humus status (SOC concentration and stock, fabric of horizons) of the SS remains practically unchangeable. The mean mineral soils SOC stocks, EP quality and SOC distribution in soil profiles depend mainly on the water regime, mineral composition (texture, calcareousness), development of eluvial processes and the land use peculiarities of soils. The mean area weighted SC SOC stock of Estonian mineral soils is 99.9 Mg ha–1, thereby the mean hydromorphic soils SOC retention capacity considerably exceeds the SOC retention capacity of automorphic soils (means are accordingly 127.5 and 78.9 Mg ha–1). The sustainable management of SOC is based on adequate information about actual SOC stocks and theoretically established or optimal humus status levels of soil types. The aggregate of SOC retained in the mineral soils of Estonia (3,235,100 ha) amounts to 323 ± 46 Tg (1 Tg = 1012 g). Approximately 42% of this is sequestered into stabilized humus, 40% into instable raw-humous material and 18% into forest (grassland) floor and shallow peat layers.
基金supported by the National Basic Research Program of China(2010CB833504)the CAS Strategic Priority Research Program(XDA05050702)the National Natural Science Foundation of China(31290221)
文摘Forests play an important role in acting as a carbon sink of terrestrial ecosystem.Although global forests have huge carbon carrying capacity(CCC)and carbon sequestration potential(CSP),there were few quantification reports on Chinese forests.We collected and compiled a forest biomass dataset of China,a total of 5841 sites,based on forest inventory and literature search results.From the dataset we extracted 338 sites with forests aged over 80 years,a threshold for defining mature forest,to establish the mature forest biomass dataset.After analyzing the spatial pattern of the carbon density of Chinese mature forests and its controlling factors,we used carbon density of mature forests as the reference level,and conservatively estimated the CCC of the forests in China by interpolation methods of Regression Kriging,Inverse Distance Weighted and Partial Thin Plate Smoothing Spline.Combining with the sixth National Forest Resources Inventory,we also estimated the forest CSP.The results revealed positive relationships between carbon density of mature forests and temperature,precipitation and stand age,and the horizontal and elevational patterns of carbon density of mature forests can be well predicted by temperature and precipitation.The total CCC and CSP of the existing forests are 19.87 and 13.86 Pg C,respectively.Subtropical forests would have more CCC and CSP than other biomes.Consequently,relying on forests to uptake carbon by decreasing disturbance on forests would be an alternative approach for mitigating greenhouse gas concentration effects besides afforestation and reforestation.
基金financially supported by the National Natural Science Foundation of China(no.42371272)the Hainan Provincial Natural Science Foundation of China(721RC1048)
文摘Mangrove restoration is recognized as an effective strategy for enhancing the carbon storage capacity of natural ecosystems,advancing toward the“carbon neutrality”goal.The carbon storage effects of ecological restoration efforts remain insufficiently understood as previous studies have focused on carbon storage dynamics in ecosystems,yet the specific impacts of targeted mangrove restoration are less explored.This study utilizes multi-temporal remote sensing data and actual restoration data from Dongzhai Harbor Hainan Island to identify the mangrove wetland coverage and quantify the spatiotemporal evolution of carbon storage under various restoration efforts using the InVEST model.Additionally,we employed the PLUS model to simulate and compare carbon storage potential under multiple development goals.The findings reveal the following:(a)Mangrove restoration significantly increased the area of land with high carbon sink capability,resulting in a regional carbon storage increase of 210,001.68 tons from 2015 to 2021,with 97%of this increase attributable to ecological restoration.(b)Mangrove coverage is crucial for regional carbon storage,with an average of 443 tons of carbon stored per hectare.Decreases in carbon storage occurred mainly during the conversion of mangroves to aquaculture,and forests/agriculture to residential areas.Increases in carbon storage were seen in the reverse transitions.(c)Comparing the scenarios focused solely on mangrove protection with cultivated land protection,the carbon storage in Dongzhai Harbor is projected to reach its maximum by 2045 under the carbon storage priority scenario.Our findings build a scientific foundation for formulating effective mangrove conservation and restoration strategies.
文摘Background： Pulmonary alveolar proteinosis （PAP） is a rare lung disease, the most common type of which is autoimmune PAP. The gold standard therapy for PAP is whole lung lavage （WLL）. Few studies have reported the optimal technique with which to evaluate the response to WLL. In this study, we aimed to identify parameters with which to assess the need for repeat WLL during a long-term 8-year follow-up. Methods： We conducted a retrospective analysis of 120 patients with autoimmune PAP with 80 of whom underwent WLL. Physiologic, serologic, and radiologic features of the patients were analyzed during an 8-year follow-up after the first WLL treatment. Results： Of the 40 patients without any intervention, 39 patients either achieved remission or remained stable and only one died of pulmonary infection. Of the 56 patients who underwent WLL for 1 time, 55 remained free from a second WLL and 1 patient died of cancer. Twenty-four required additional treatments after their first WLL. The baseline PaO2, （P = 0.000）, PA-aO2 （P = 0.000）, shunt fraction rate （P = 0.001）, percent of predicted normal diffusing capacity of the lung for carbon monoxide （DLCO%Pred） （P = 0.016）, 6-rain walk test （P = 0.013）, carcinoembryonic antigen （CEA） （P = 0.007）, and neuron-specific enolase （NSE） （P = 0.003） showed significant differences among the three groups. The need for a second WLL was significantly associated with PaO2 （P = 0.000）, CEA （P= 0.050）, the 6-minute walk test （P= 0.026）, and DLCO%Pred （P = 0.041 ）. The DLCO%Pred on admission with a cut-off value of42.1% （P = 0.001） may help to distinguish whether patients with PAP require a second WLL. Conclusions： WLL is the optimal treatment method for PAP and provides remarkable improvements for affected patients. The DLCO%Pred on admission with a cut-offvalue of 42.1% may distinguish whether patients with PAP require a second WLL.
