Fischer-Tropsch synthesis offers a promising route to convert carbon-rich resources such as coal,natural gas,and biomass into clean fuels and high-value chemicals via syngas.Catalyst development is crucial for optimiz...Fischer-Tropsch synthesis offers a promising route to convert carbon-rich resources such as coal,natural gas,and biomass into clean fuels and high-value chemicals via syngas.Catalyst development is crucial for optimizing the process,with cobalt-and iron-based catalysts being widely used in industrial applications.Iron-based catalysts,in particular,are favored due to their low cost,broad temperature range,and high water-gas shift reaction activity,making them ideal for syngas derived from coal and biomass with a low H_(2)/CO ratio.However,despite their long history of industrial use,iron-based catalysts face two significant challenges.First,the presence of multiple iron phases-metallic iron,iron oxides,and iron carbides-complicates the understanding of the reaction mechanism due to dynamic phase transformations.Second,the high water-gas shift activity of these catalysts leads to increased CO_(2) selectivity,thereby reducing overall carbon efficiency.In Fischer-Tropsch synthesis,CO_(2) can arise as primary CO_(2) from CO disproportionation(the Boudouard reaction)and as secondary CO_(2) from the water-gas shift reaction.The accumulation of CO_(2) formation further compromises overall carbon efficiency,which is particularly undesirable given the current focus on minimizing carbon emissions and achieving carbon neutrality.This review focus on the ongoing advancements of iron-based catalysts for Fischer-Tropsch synthesis,with particular emphasis on overcoming these two critical challenges for iron-based catalysts:regulating the active phases and minimizing CO_(2) selectivity.Addressing these challenges is essential for enhancing the overall catalytic efficiency and selectivity of iron-based catalysts.In this review,recent efforts to suppress CO_(2) selectivity of iron-based catalysts,including catalyst hydrophobic modification and graphene confinement,are explored for their potential to stabilize active phases and prevent unwanted side reactions.This innovative approach offers new opportunities for developing catalysts with high activity,low CO_(2) selectivity,and enhanced stability,which are key factors for enhancing both the efficiency and sustainability for Fischer-Tropsch synthesis.Such advancements are crucial for advancing more efficient and sustainable Fischer-Tropsch synthesis technologies,supporting the global push for net-zero emissions goals,and contributing to carbon reduction efforts worldwide.展开更多
Green and low-carbon is a new development model that seeks balance between environmental sustainability and high economic growth.If explainable and available carbon emission data can be accurately obtained,it will hel...Green and low-carbon is a new development model that seeks balance between environmental sustainability and high economic growth.If explainable and available carbon emission data can be accurately obtained,it will help policy regulators and enterprise managers to more accurately implement this development strategy.A lot of research has been carried out,but it is still a difficult problem that how to accommodate and adapt the complex carbon emission data computing models and factor libraries developed by different regions,different industries and different enterprises.Meanwhile,with the rapid development of the Industrial Internet,it has not only been used for the supply chain optimization and intelligent scheduling of the manufacturing industry,but also been used by more and more industries as an important way of digital transformation.Especially in China,the Industrial Internet identification and resolution system is becoming an important digital infrastructure to uniquely identify objects and share data.Hence,a compatible carbon efficiency information service framework based on the Industrial Internet Identification is proposed in this paper to address the problem of computing and querying multi-source heterogeneous carbon emission data.We have defined a multi cooperation carbon emission data interaction model consisting of three roles and three basic operations.Further,the implementation of the framework includes carbon emission data identification,modeling,calculation,query and sharing.The practice results show that its capability and effectiveness in improving the responsiveness,accuracy,and credibility of compatible carbon efficiency data query and sharing services.展开更多
Urban energy systems(UESs)play a pivotal role in the consumption of clean energy and the promotion of energy cascade utilization.In the context of the construction and operation strategy of UESs with multiple compleme...Urban energy systems(UESs)play a pivotal role in the consumption of clean energy and the promotion of energy cascade utilization.In the context of the construction and operation strategy of UESs with multiple complementary energy resources,a comprehensive assessment of the energy efficiency is of paramount importance.First,a multi-dimensional evaluation system with four primary indexes of energy utilization,environmental protection,system operation,and economic efficiency and 21 secondary indexes is constructed to comprehensively portray the UES.Considering that the evaluation system may contain a large number of indexes and that there is overlapping information among them,an energy efficiency evaluation method based on data processing,dimensionality reduction,integration of combined weights,and gray correlation analysis is proposed.This method can effectively reduce the number of calculations and improve the accuracy of energy efficiency assessments.Third,a demonstration project for a UES in China is presented.The energy efficiency of each scenario is assessed using six operational scenarios.The results show that Scenario 5,in which parks operate independently and investors build shared energy-storage equipment,has the best results and is best suited for green and low-carbon development.The results of the comparative assessment methods show that the proposed method provides a good energy efficiency assessment.This study provides a reference for the optimal planning,construction,and operation of UESs with multiple energy sources.展开更多
The combined application of organic manure and chemical fertilizers is an effective way to enhance soil organic carbon(SOC)sequestration through its influences on organic carbon(OC)input and the stability of SOC fract...The combined application of organic manure and chemical fertilizers is an effective way to enhance soil organic carbon(SOC)sequestration through its influences on organic carbon(OC)input and the stability of SOC fractions.However,there is limited information on the carbon sequestration efficiency(CSE)of chemically separated SOC fractions and its response to OC input under long-term fertilization regimes,especially at different sites.This study used three long-term fertilization experiments in Gongzhuling,Zhengzhou and Qiyang spanning 20 years to compare the stocks and CSE in four different OC fractions(very labile OC,labile OC,less labile OC,and non-labile OC)and their relationships with annual OC input.Three treatments of no fertilization(CK),chemical nitrogen,phosphorous,and potassium fertilizers(NPK),and chemical NPK combined with manure(NPKM)were employed.The results showed that compared with CK,NPKM resulted in enhanced SOC stocks and sequestration rates as well as CSE levels of all fractions irrespective of experimental site.Specifically for the very labile and non-labile OC fractions,NPKM significantly increased the SOC stocks by 43 and 83%,77 and 86%,and 73 and 82%in Gongzhuling,Qiyang,and Zhengzhou relative to CK,respectively.However,the greatest changes in SOC stock relative to the initial value were associated with non-labile OC fractions in Gongzhuling,Zhengzhou,and Qiyang,which reached 6.65,7.16,and 7.35 Mg ha^(-1) under NPKM.Similarly,the highest CSE was noted for non-labile OC fractions under NPKM followed sequentially by the very labile OC,labile OC,and less-labile OC fractions,however a CSE of 8.56%in the non-labile OC fraction for Gongzhuling was higher than the values of 6.10 and 4.61%in Zhengzhou and Qiyang,respectively.In addition,the CSE for the passive pool(very labile+labile OC fractions)was higher than the active pool(less-labile+non-labile OC fractions),with the highest value in Gongzhuling.The redundancy analysis revealed that the CSEs of fractions and pools were negatively influenced by annual OC input,mean annual precipitation and temperature,but positively influenced by the initial SOC and total nitrogen contents.This suggests that differential stability of sequestered OC is further governed by indigenous site characteristics and variable amounts of annual OC input.展开更多
Strategically improving carbon emission efficiency(CEE)through digital intelligence technology innovation(DITI)is imperative to capitalize on emerging opportunities for economic decarbonization and low-carbon green de...Strategically improving carbon emission efficiency(CEE)through digital intelligence technology innovation(DITI)is imperative to capitalize on emerging opportunities for economic decarbonization and low-carbon green development.This study employs panel data from 283 Chinese cities from 2011 to 2021 to examine the influence of DITI on urban CEE.The findings suggest the following:①DITI is crucial in enhancing CEE,and it exerts spatial spillover effects on neighboring areas.②Following the transition to a low-carbon energy system,DITI is instrumental in enhancing CEE by reducing the energy consumption scale,optimizing the energy consumption structure,and controlling the energy consumption intensity.③DITI has varying effects on CEE when subjected to multidimensional regulations,including fiscal pressure,fiscal decentralization,private economics,and entrepreneurial vitality.④The beneficial impact of DITI on CEE is more pronounced in regions with high economic growth,low natural resource endowments,high digital resource endowments,and in cities in central China.This study emphasizes DITI’s crucial role in promoting a low-carbon,green circular,and energy-efficient digital economy.展开更多
The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,expl...The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,exploring the provincial variations in carbon emission efficiency(CEE)in the building sector and identifying the effect of BEESs on CEE is crucial.This study focuses on commercial buildings in China and applies a difference in differences model to evaluate the impact of BEESs on the CEE of commercial buildings.The slacks-based measure–data envelopment analysis model is employed to assess the CEE of commercial buildings in 30 Chinese provinces from 2000 to 2019.Furthermore,heterogeneous tests are used to explore how climate characteristics and economic conditions affect the efficiency of BEESs.The results indicate that BEESs positively influence the CEE of commercial buildings.Specifically,a 1%increase in the intensity of BEESs causes a 0.1484%increase in the CEE of commercial buildings.Moreover,the impact of BEESs is particularly pronounced in the southern and western provinces.This study provides valuable scientific evidence for governments to enhance BEESs implementation.展开更多
Tibetan alpine steppes are large and sensitive terrestrial carbon(C)reservoirs that are experiencing desertification due to global change and overgrazing,which can lead to stronger resource limitations for both above-...Tibetan alpine steppes are large and sensitive terrestrial carbon(C)reservoirs that are experiencing desertification due to global change and overgrazing,which can lead to stronger resource limitations for both above-and belowground communities.Soil nutrients,especially nitrogen(N)and phosphorus(P),are the crucial resources for plant growth and microbial metabolism.However,whether both plant and soil microbial communities in the degraded alpine steppes are limited by these soil nutrients remains unclear,which limits our understanding of the mechanisms of desertification and subsequent ecosystem restoration.Here,we evaluated potential nutrient limitations of the plant and soil microbial communities in the alpine steppe across five stages of desertification using stoichiometry-based approaches.Our results showed that soil microbial metabolism was mainly limited by C and P,and the plant N limitation and microbial C limitation were intensified while the microbial P limitation was relieved during desertification.Plant-soil-microbe interactions had significant impacts on the microbial C and P limitations,explaining 72 and 61%of the variation,respectively.Specifically,desertification ultimately affected microbial metabolic limitations by regulating soil pH,soil nutrients,and the plant N limitation.Moreover,the microbial C limitation further reduced microbial C use efficiency(CUE)with desertification,which is detrimental for organic C retention in the degraded soil.Overall,this study revealed that microbial metabolic limitations through plant-microbe interactions were the key drivers affecting soil microbial CUE,and it provided insights that can advance our knowledge of the microbial regulation of nutrient cycles and C sequestration.展开更多
Enhanced silicate weathering(ESW)is a geoengineering method aimed at accelerating carbon dioxide(CO_(2))removal(CDR)from atmosphere by increasing the weathering flux of silicate rocks and minerals.It has emerged as a ...Enhanced silicate weathering(ESW)is a geoengineering method aimed at accelerating carbon dioxide(CO_(2))removal(CDR)from atmosphere by increasing the weathering flux of silicate rocks and minerals.It has emerged as a promising strategy for CDR.Theoretical studies underscore ESW’s substantial potential for CDR and its diverse benefits for crops when applied to croplands.However,the well-known significant discrepancies in silicate weathering rates between laboratory and field conditions introduce uncertainty in CDR through ESW.By compiling data from recent literature,we calculated and compared CDR efficiency(t CO_(2)t^(-1)_(silicate)ha^(-1)y^(-1))observed in mesocosm experiments and field trials.The findings indicate that CDR efficiencies in field trials are comparable to or exceeding that observed in mesocosm experiments by 1-3 orders of magnitude,particularly evident with wollastonite application.The hierarchy of CDR efficiency among silicates suitable for ESW is ranked as follows:olivine≥wollastonite>basalt>albite≥anorthite.We suggest the potential role of biota,especially fungi,in contributing to higher CDR efficiencies observed in field trials compared to mesocosm experiments.We further emphasize introducing fungi known for their effectiveness in silicate weathering could potentially enhance CDR efficiency through ESW in croplands.But before implementing fungal-facilitated ESW,three key questions need addressing:(i)How does the community of introduced fungi evolve over time?(ii)What is the long-term trajectory of CDR efficiency following fungal introduction?and(iii)Could fungal introduction lead to organic matter oxidation,resulting in elevated CO_(2)emissions?These investigations are crucial for optimizing the efficiency and sustainability of fungal-facilitated ESW strategy.展开更多
Low-carbon manufacturing(LCM)is increasingly being regarded as a new sustainable manufacturing model of carbon emission reduction in the manufacturing industry.In this paper,a two-stage low-carbon scheduling optimizat...Low-carbon manufacturing(LCM)is increasingly being regarded as a new sustainable manufacturing model of carbon emission reduction in the manufacturing industry.In this paper,a two-stage low-carbon scheduling optimization method of job shop is presented as part of the efforts to implement LCM,which also aims to reduce the processing cost and improve the efficiency of a mechanical machining process.In the first stage,a task assignment optimization model is proposed to optimize carbon emissions without jeopardizing the processing efficiency and the profit of a machining process.Non-dominated sorting genetic algorithm II and technique for order preference by similarity to an ideal solution are then adopted to assign the most suitable batch task of different parts to each machine.In the second stage,a processing route optimization model is established to plan the processing sequence of different parts for each machine.Finally,niche genetic algorithm is utilized to minimize the makespan.A case study on the fabrication of four typical parts of a machine tool is demonstrated to validate the proposed method.展开更多
Based on the input-output data from 2002 to 2017,this paper combined the three-stage DEA model with the non-competitive I-O model and measured the embodied carbon efficiency of export trade in China’s 26 product sect...Based on the input-output data from 2002 to 2017,this paper combined the three-stage DEA model with the non-competitive I-O model and measured the embodied carbon efficiency of export trade in China’s 26 product sectors,and further investigated its influencing factors and convergence issues.The results of the study showed that:①The embodied carbon efficiency of export trade in China’s overall product sector demonstrated a positive development trend from 2002 to 2017,and this positive trend was more obvious after the implementation of conservation culture construction in 2012.But the differences of embodied carbon emission efficiency level among the product sectors were still significant.②Measured by the K-means clustering analysis method,this study found that agriculture,other service industries,wholesale and retail industries,catering industry,construction industry and manufacturing industry with strong innovation ability were mostly concentrated at high and medium efficiency levels,while industrial sectors with resource dependence and high energy consumption,such as metal smelting and rolling processing industries,non metallic mineral products industry,and coal mining industry,were at a low efficiency level.③All product sectors hadσconvergence,absoluteβconvergence and conditionalβconvergence during 2002-2010 and 2010-2017,and the level of each product sector in 2010-2017 was higher than that in 2002-2010 according to the perspective of convergence speed and degree of convergence.④Technological progress had not fully played a role in suppressing energy consumption and improving the efficiency of embodied carbon efficiency,and it would also widen the gap between the embodied carbon emission efficiency levels of various product sectors.The expansion of trade scale could effectively improve carbon emission efficiency and narrow the gap between sectors.Environmental regulation could effectively promote the improvement of embodied carbon emission efficiency but would widen the level gap between sectors.These findings indicate that China needs to build a sound environmental regulation system for the development of low-carbon trade,continue to reasonably expand the scale of trade,eliminate backward industries with production capacity,vigorously develop low-carbon technologies such as new energy,strengthen the exchange of low carbon technologies and industrial cooperation among sectors,and promote coordinated development among industries.展开更多
Understanding of the vegetation dynamics is essential for addressing the potential threats of terrestrial ecosystem.In recent years,the vegetation coverage of the Yangtze River Basin(YRB)has increased significantly,ye...Understanding of the vegetation dynamics is essential for addressing the potential threats of terrestrial ecosystem.In recent years,the vegetation coverage of the Yangtze River Basin(YRB)has increased significantly,yet the spatio-temporal variations and potential driving meteorological factors of carbon use efficiency(CUE)under the context of global warming are still not clear.In this study,MODIS-based public-domain data during 2000–2015 was used to analyze these aspects in the YRB,a large river basin with powerful ecological functions in China.Spatio-temporal variations of CUE in different sub-basins and land cover types were investigated and the correlations with potential driving meteorological factors were examined.Results revealed that CUE in the YRB had strong spatiotemporal variability and varied remarkably in different land cover types.For the whole YRB,the average CUE of vegetated land was 0.519,while the long-term change trend of CUE was obscure.Along the rising altitude,CUE generally showed an increasing trend until the altitude of 3900 m and then followed by a decreasing trend.CUE of grasslands was generally higher than that of croplands,and then forest lands.The inter-annual variation of CUE in the YRB is likely to be driven by precipitation as a strong positive partial correlation between the inter-annual variability of CUE and precipitation was observed in most of sub-basins and land cover types in the YRB.The influence of temperature and relative humidity is also outstanding in certain regions and land cover types.Our findings are useful from the view point of carbon cycle and reasonable land cover management under the context of global warming.展开更多
To quantitatively address the role of tissue N in crop respiration under various agricultural practices, and to consequently evaluate the impact of synthetic fertilizer N application on biomass production and respirat...To quantitatively address the role of tissue N in crop respiration under various agricultural practices, and to consequently evaluate the impact of synthetic fertilizer N application on biomass production and respiration, and hence net carbon fixation efficiency （Encf）, pot and field experiments were carried out for an annual rotation of a rice-wheat cropping system from 2001 to 2003. The treatments of the pot experiments included fertilizer N application, sowing date and planting density. Different rates of N application were tested in the field experiments. Static opaque chambers were used for sampling the gas. The respiration as CO2 emission was detected by a gas chromatograph. A successive biomass clipping method was employed to determine the crop autotrophic respiration coefficient （Ra）. Results from the pot experiments revealed a linear relationship between Ra and tissue N content as Ra = 4.74N-1.45 （R^2= 0.85, P 〈 0.001）. Measurements and calculations from the field experiments indicated that fertilizer N application promoted not only biomass production but also increased the respiration of crops. A further investigation showed that the increase of carbon loss in terms of respiration owing to fertilizer N application exceeded that of net carbon gain in terms of aboveground biomass when fertilizer N was applied over a certain rate. Consequently, the Encf declined as the N application rate increased.展开更多
Grasping the spatial correlation structure of transportation carbon emission efficiency(TCEE)and its influencing factors is significant for promoting high-quality and coordinated development of the transportation indu...Grasping the spatial correlation structure of transportation carbon emission efficiency(TCEE)and its influencing factors is significant for promoting high-quality and coordinated development of the transportation industry and the relevant region.Based on the ideal point cross-efficiency(IPCE)model,the social network analysis method was employed herein to explore the spatial correlation network structure of China’s provincial TCEE and its influencing factors.The results obtained showed the following outcomes.(1)During the study period,China’s provincial TCEE formed a complex and multithreaded network association relationship,but its network association structure was still relatively loose and presented the hierarchical gradient characteristics of dense in the east and sparse in the west.(2)The correlation of China’s TCEE formed a block segmentation based on the regional boundaries,and its factional structure was relatively obvious.The eastern region was closely connected with the central region,and generally connected with the western and northeastern regions.The central region was mainly connected with the eastern and western regions,and relatively less connected with the northeastern region.Besides,the northeastern region was weakly connected with the western region.(3)Shanghai,Beijing,Zhejiang,Guangdong,Jiangsu,Tianjin,and other developed provinces were in the core leading position in the TCEE network,which significantly impacted the spatial correlation of TCEE.However,Heilongjiang,Jilin,Xinjiang,Qinghai,and other remote provinces in the northeast and northwest were at the absolute edge of the network,which weakly impacted the spatial correlation of TCEE.(4)Provincial distance,economic development-level difference,transportation intensity difference,and transportation structure difference had significant negative impacts on the spatial correlation network of China’s provincial TCEE.In contrast,the energy-saving technology level difference had a significant positive impact on it.The regression coefficients of transportation energy structure and environmental regulation differences were positive but insignificant;their response mechanism and effects need to be improved and enhanced.展开更多
This paper uses an input-output table of China's provinces(2007-2016)to measure carbon emissions of these industries.It employs a Malmquist-Luenberger(ML)index with expected and undesired outputs,and an absoluteβ...This paper uses an input-output table of China's provinces(2007-2016)to measure carbon emissions of these industries.It employs a Malmquist-Luenberger(ML)index with expected and undesired outputs,and an absoluteβconvergence and a conditionalβconvergence model,to conduct an in-depth analysis of dynamic changes and spatial convergence.Carbon emission efficiency of forest processing industries in 25 regions,including Shanghai,Chongqing,Zhejiang,and Jiangsu are increasing,whereas those of Tianjin,Liaoning,Heilongjiang,and Xizang are decreasing.The main contributing factors of carbon emission efficiency in three major regions vary over time.Further,carbon emission efficiency in the eastern,central,and western regions all have absoluteβconvergence and conditionalβconvergence,indicating that different regions are developing toward their own goals and industry,yet regions with lower efficiency are catching up with those where with more efficient strategies in place.Finally,this paper proposes according recommendations.展开更多
To measure the carbon emission efficiency of China’s pharmaceutical manufacturing industry, explore the factors affecting the carbon emission efficiency of China’s pharmaceutical manufacturing industry, and provide ...To measure the carbon emission efficiency of China’s pharmaceutical manufacturing industry, explore the factors affecting the carbon emission efficiency of China’s pharmaceutical manufacturing industry, and provide reference for improving the carbon emission efficiency of China’s pharmaceutical manufacturing industry and promoting the government to formulate macro policies. Based on the data of the pharmaceutical manufacturing industry in 30 provinces of China from 2010 to 2019, and based on the SBM model and ML (Malmquist-Luenberger) index model, the carbon emission efficiency of the pharmaceutical manufacturing industry was calculated and its dynamic change was investigated, and the Tobit model was further used to explore the influencing factors of the carbon emission efficiency of the pharmaceutical manufacturing industry. The carbon emission efficiency of China’s inter-provincial pharmaceutical manufacturing industry has steadily improved. The carbon emission efficiency of the eastern region is higher than that of the western region, and that of the western region is higher than that of the central region. The eastern region is dominated by technological progress, and there is room for improvement in technological efficiency. The central and western regions are dominated by technological efficiency. Compared with technological efficiency, technological progress needs to be further improved. Environmental regulation, industrial agglomeration and technological innovation level positively affect carbon emission efficiency, while foreign investment level has no significant impact on carbon emission efficiency.展开更多
Transportation accounts for 80% of open-cut coal mine carbon emissions. With regard to the energy con- sumption and carbon emissions of transportation within an open-cut mine, this paper systematically compared the wo...Transportation accounts for 80% of open-cut coal mine carbon emissions. With regard to the energy con- sumption and carbon emissions of transportation within an open-cut mine, this paper systematically compared the work and energy consumption of a truck and belt conveyor on a theoretical basis, and con- structed a model to calculate the energy consumption of open-cut mine transportation. Life cycle carbon emission factors and power consumption calculation model were established through a Process Analysis- Life Cycle Analysis （PA-LCA）. The following results were obtained： （1） the energy consumption of truck transportation was four to twelve times higher than that of the belt conveyor; （2） the C02 emissions from truck transportation were three to ten times higher than those of the belt conveyor; （3） with the increase in the slope angle for transportation, the ratio of truck to belt conveyor for both energy consumption and carbon emissions gradually decreased; （4） based on 2013 prices in China, the energy cost of transportation using a belt conveyor in open-cut coal mines could save 0.6-2.4 Yuan/（t kin） compared to truck transportation.展开更多
Water-use efficiency（WUE） is a key plant functional trait that plays a central role in the global cycles of water and carbon. Although increasing precipitation may cause vegetation changes, few studies have explored...Water-use efficiency（WUE） is a key plant functional trait that plays a central role in the global cycles of water and carbon. Although increasing precipitation may cause vegetation changes, few studies have explored the linkage between alteration in vegetation and WUE. Here, we analyzed the responses of leaf WUE, ecosystem carbon and water exchanges, ecosystem WUE, and plant community composition changes under normal conditions and also under extra 15% or 30% increases in annual precipitation in a temperate desert ecosystem of Xinjiang, China. We found that leaf WUE and ecosystem WUE showed inconsistent responses to increasing precipitation. Leaf WUE consistently decreased as precipitation increased. By contrast, the responses of the ecosystem WUE to increasing precipitation are different in different precipitation regimes： increasing by 33.9% in the wet year（i.e., the normal precipitation years）and decreasing by 4.1% in the dry year when the precipitation was about 30% less than that in the wet year.We systematically assessed the herbaceous community dynamics, community composition, and vegetation coverage to explain the responses of ecosystem WUE, and found that the between-year discrepancy in ecosystem WUE was consistent with the extent to which plant biomass was stimulated by the increase in precipitation. Although there was no change in the relative significance of ephemerals in the plant community, its greater overall plant biomass drove an increased ecosystem WUE under the conditions of increasing precipitation in 2011. However, the slight increase in plant biomass exerted no significant effect on ecosystem WUE in 2012. Our findings suggest that an alteration in the dominant species in this plant community can induce a shift in the carbon-and water-based economics of desert ecosystems.展开更多
Abies fabri is a typical subalpine dark coniferous forest in southwestern China. Air temperature increases more at high elevation areas than that at low elevation areas in mountainous regions,and climate change ratio ...Abies fabri is a typical subalpine dark coniferous forest in southwestern China. Air temperature increases more at high elevation areas than that at low elevation areas in mountainous regions,and climate change ratio is also uneven in different seasons. Carbon gain and the response of water use efficiency(WUE) to annual and seasonal increases in temperature with or without CO_2 fertilization were simulated in Abies fabri using the atmospheric-vegetation interaction model(AVIM2). Four future climate scenarios(RCP2.6,RCP4.5,RCP6.0 and RCP8.5) from the Coupled Model Intercomparison Project Phase 5(CMIP5) were selectively investigated. The results showed that warmer temperatures have negative effects on gross primary production(GPP) and net primary production(NPP) in growing seasons and positive effects in dormant seasons due to the variation in the leaf area index. Warmer temperatures tend to generate lower canopy WUE and higher ecosystem WUE in Abies fabri. However,warmer temperature together with rising CO_2 concentrations significantlyincrease the GPP and NPP in both growing and dormant seasons and enhance WUE in annual and dormant seasons because of the higher leaf area index(LAI) and soil temperature. The comparison of the simulated results with and without CO_2 fertilization shows that CO_2 has the potential to partially alleviate the adverse effects of climate warming on carbon gain and WUE in subalpine coniferous forests.展开更多
Manipulated precipitation patterns can profoundly influence the metabolism of soil microorganisms.However,the responses of soil organic carbon(SOC)and nutrient turnover to microbial metabolic limitation under changing...Manipulated precipitation patterns can profoundly influence the metabolism of soil microorganisms.However,the responses of soil organic carbon(SOC)and nutrient turnover to microbial metabolic limitation under changing precipitation conditions remain unclear in semi-arid ecosystems.This study measured the potential activities of enzymes associated with carbon(C:β-1,4-glucosidase(BG)andβ-D-cellobiosidase(CBH)),nitrogen(N:β-1,4-N-acetylglucosaminidase(NAG)and L-leucine aminopeptidase(LAP))and phosphorus(P:alkaline phosphatase(AP))acquisition,to quantify soil microbial metabolic limitations using enzymatic stoichiometry,and then identify the implications for soil microbial metabolic limitations and carbon use efficiency(CUE)under decreased precipitation by 50%(DP)and increased precipitation by 50%(IP)in a temperate grassland.The results showed that soil C and P were the major elements limiting soil microbial metabolism in temperate grasslands.There was a strong positive dependence between microbial C and P limitations under manipulated precipitation.Microbial metabolism limitation was promoted by DP treatment but reversed by IP treatment.Moreover,CUE was inhibited by DP treatment but promoted by IP treatment.Soil microbial metabolism limitation was mainly regulated by soil moisture and soil C,N,and P stoichiometry,followed by available nutrients(i.e.,NO^(-)_(3),NH^(+)_(4),and dissolved organic C)and microbial biomass(i.e.,MBC and MBN).Overall,these findings highlight the potential role of changing precipitation in regulating ecosystem C turnover by limiting microbial metabolism and CUE in temperate grassland ecosystems.展开更多
Biochar has been widely recognized for its potential to increase carbon(C)sequestration and mitigate climate change.This potential is affected by how biochar interacts with native soil organic carbon(SOC)and fresh org...Biochar has been widely recognized for its potential to increase carbon(C)sequestration and mitigate climate change.This potential is affected by how biochar interacts with native soil organic carbon(SOC)and fresh organic substrates added to soil.However,only a few studies have been conducted to understand this interaction.To fill this knowledge gap,we conducted a ^(13)C-glucose labelling soil incubation for 6 months using fine-textured agricultural soil(Stagnosol)with two different biochar amounts.Biochar addition reduced the mineralization of SOC and ^(13)C-glucose and increased soil microbial biomass carbon(MBC)and microbial carbon use efficiency(CUE).The effects were found to be additive i.e.,higher biochar application rate resulted in lower mineralization of SOC and ^(13)C-glucose.Additionally,soil density fractionation after 6 months revealed that most of the added biochar particles were recovered in free particulate organic matter(POM)fraction.Biochar also increased the retention of ^(13)C in free POM fraction,indicating that added ^(13)C-glucose was preserved within the biochar particles.The measurement of ^(13)C from the total amino sugar fraction extracted from the biochar particles suggested that biochar increased the microbial uptake of added ^(13)C-glucose and after they died,the dead microbial residues(necromass)accumulated inside biochar pores.Biochar also increased the proportion of occluded POM,demonstrating that increased soil occlusion following biochar addition reduced SOC mineralization.Overall,the study demonstrates the additional C sequestering potential of biochar by inducing negative priming of native SOC as well as increasing CUE,resulting in the formation and stabilization of microbial necromass.展开更多
文摘Fischer-Tropsch synthesis offers a promising route to convert carbon-rich resources such as coal,natural gas,and biomass into clean fuels and high-value chemicals via syngas.Catalyst development is crucial for optimizing the process,with cobalt-and iron-based catalysts being widely used in industrial applications.Iron-based catalysts,in particular,are favored due to their low cost,broad temperature range,and high water-gas shift reaction activity,making them ideal for syngas derived from coal and biomass with a low H_(2)/CO ratio.However,despite their long history of industrial use,iron-based catalysts face two significant challenges.First,the presence of multiple iron phases-metallic iron,iron oxides,and iron carbides-complicates the understanding of the reaction mechanism due to dynamic phase transformations.Second,the high water-gas shift activity of these catalysts leads to increased CO_(2) selectivity,thereby reducing overall carbon efficiency.In Fischer-Tropsch synthesis,CO_(2) can arise as primary CO_(2) from CO disproportionation(the Boudouard reaction)and as secondary CO_(2) from the water-gas shift reaction.The accumulation of CO_(2) formation further compromises overall carbon efficiency,which is particularly undesirable given the current focus on minimizing carbon emissions and achieving carbon neutrality.This review focus on the ongoing advancements of iron-based catalysts for Fischer-Tropsch synthesis,with particular emphasis on overcoming these two critical challenges for iron-based catalysts:regulating the active phases and minimizing CO_(2) selectivity.Addressing these challenges is essential for enhancing the overall catalytic efficiency and selectivity of iron-based catalysts.In this review,recent efforts to suppress CO_(2) selectivity of iron-based catalysts,including catalyst hydrophobic modification and graphene confinement,are explored for their potential to stabilize active phases and prevent unwanted side reactions.This innovative approach offers new opportunities for developing catalysts with high activity,low CO_(2) selectivity,and enhanced stability,which are key factors for enhancing both the efficiency and sustainability for Fischer-Tropsch synthesis.Such advancements are crucial for advancing more efficient and sustainable Fischer-Tropsch synthesis technologies,supporting the global push for net-zero emissions goals,and contributing to carbon reduction efforts worldwide.
基金supported by the 2018 Industrial Internet Innovation and Development Project——Industrial Internet Identification Resolution Sys⁃tem:National Top-Level Node Construction Project(Phase I).
文摘Green and low-carbon is a new development model that seeks balance between environmental sustainability and high economic growth.If explainable and available carbon emission data can be accurately obtained,it will help policy regulators and enterprise managers to more accurately implement this development strategy.A lot of research has been carried out,but it is still a difficult problem that how to accommodate and adapt the complex carbon emission data computing models and factor libraries developed by different regions,different industries and different enterprises.Meanwhile,with the rapid development of the Industrial Internet,it has not only been used for the supply chain optimization and intelligent scheduling of the manufacturing industry,but also been used by more and more industries as an important way of digital transformation.Especially in China,the Industrial Internet identification and resolution system is becoming an important digital infrastructure to uniquely identify objects and share data.Hence,a compatible carbon efficiency information service framework based on the Industrial Internet Identification is proposed in this paper to address the problem of computing and querying multi-source heterogeneous carbon emission data.We have defined a multi cooperation carbon emission data interaction model consisting of three roles and three basic operations.Further,the implementation of the framework includes carbon emission data identification,modeling,calculation,query and sharing.The practice results show that its capability and effectiveness in improving the responsiveness,accuracy,and credibility of compatible carbon efficiency data query and sharing services.
基金supported by the National Natural Science Foundation of China under Grant 51567002 and Grant 50767001.
文摘Urban energy systems(UESs)play a pivotal role in the consumption of clean energy and the promotion of energy cascade utilization.In the context of the construction and operation strategy of UESs with multiple complementary energy resources,a comprehensive assessment of the energy efficiency is of paramount importance.First,a multi-dimensional evaluation system with four primary indexes of energy utilization,environmental protection,system operation,and economic efficiency and 21 secondary indexes is constructed to comprehensively portray the UES.Considering that the evaluation system may contain a large number of indexes and that there is overlapping information among them,an energy efficiency evaluation method based on data processing,dimensionality reduction,integration of combined weights,and gray correlation analysis is proposed.This method can effectively reduce the number of calculations and improve the accuracy of energy efficiency assessments.Third,a demonstration project for a UES in China is presented.The energy efficiency of each scenario is assessed using six operational scenarios.The results show that Scenario 5,in which parks operate independently and investors build shared energy-storage equipment,has the best results and is best suited for green and low-carbon development.The results of the comparative assessment methods show that the proposed method provides a good energy efficiency assessment.This study provides a reference for the optimal planning,construction,and operation of UESs with multiple energy sources.
基金support from the National Natural Science Foundation of China(42177341)is highly acknowledged。
文摘The combined application of organic manure and chemical fertilizers is an effective way to enhance soil organic carbon(SOC)sequestration through its influences on organic carbon(OC)input and the stability of SOC fractions.However,there is limited information on the carbon sequestration efficiency(CSE)of chemically separated SOC fractions and its response to OC input under long-term fertilization regimes,especially at different sites.This study used three long-term fertilization experiments in Gongzhuling,Zhengzhou and Qiyang spanning 20 years to compare the stocks and CSE in four different OC fractions(very labile OC,labile OC,less labile OC,and non-labile OC)and their relationships with annual OC input.Three treatments of no fertilization(CK),chemical nitrogen,phosphorous,and potassium fertilizers(NPK),and chemical NPK combined with manure(NPKM)were employed.The results showed that compared with CK,NPKM resulted in enhanced SOC stocks and sequestration rates as well as CSE levels of all fractions irrespective of experimental site.Specifically for the very labile and non-labile OC fractions,NPKM significantly increased the SOC stocks by 43 and 83%,77 and 86%,and 73 and 82%in Gongzhuling,Qiyang,and Zhengzhou relative to CK,respectively.However,the greatest changes in SOC stock relative to the initial value were associated with non-labile OC fractions in Gongzhuling,Zhengzhou,and Qiyang,which reached 6.65,7.16,and 7.35 Mg ha^(-1) under NPKM.Similarly,the highest CSE was noted for non-labile OC fractions under NPKM followed sequentially by the very labile OC,labile OC,and less-labile OC fractions,however a CSE of 8.56%in the non-labile OC fraction for Gongzhuling was higher than the values of 6.10 and 4.61%in Zhengzhou and Qiyang,respectively.In addition,the CSE for the passive pool(very labile+labile OC fractions)was higher than the active pool(less-labile+non-labile OC fractions),with the highest value in Gongzhuling.The redundancy analysis revealed that the CSEs of fractions and pools were negatively influenced by annual OC input,mean annual precipitation and temperature,but positively influenced by the initial SOC and total nitrogen contents.This suggests that differential stability of sequestered OC is further governed by indigenous site characteristics and variable amounts of annual OC input.
基金supported by the National Science Foundation of China Youth Fund Project[Grant No.72204247].
文摘Strategically improving carbon emission efficiency(CEE)through digital intelligence technology innovation(DITI)is imperative to capitalize on emerging opportunities for economic decarbonization and low-carbon green development.This study employs panel data from 283 Chinese cities from 2011 to 2021 to examine the influence of DITI on urban CEE.The findings suggest the following:①DITI is crucial in enhancing CEE,and it exerts spatial spillover effects on neighboring areas.②Following the transition to a low-carbon energy system,DITI is instrumental in enhancing CEE by reducing the energy consumption scale,optimizing the energy consumption structure,and controlling the energy consumption intensity.③DITI has varying effects on CEE when subjected to multidimensional regulations,including fiscal pressure,fiscal decentralization,private economics,and entrepreneurial vitality.④The beneficial impact of DITI on CEE is more pronounced in regions with high economic growth,low natural resource endowments,high digital resource endowments,and in cities in central China.This study emphasizes DITI’s crucial role in promoting a low-carbon,green circular,and energy-efficient digital economy.
基金funded by the National Social Science Foundation of China[Grant No.23CJY018]the Fundamental Research Funds for the Central Universities[Grant No.JBK2406049]+2 种基金the National Natural Science Foundation of China[Grant No.72003151],[Grant No.72173100]the Soft Science Research Program of Sichuan Province[Grant No.2022JDR0227]Projects from the Research Center on Xi Jinping’s Economic Thought,and the Fundamental Research Funds for the“Guanghua Talent Program”of the Southwestern University of Finance and Economics.
文摘The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,exploring the provincial variations in carbon emission efficiency(CEE)in the building sector and identifying the effect of BEESs on CEE is crucial.This study focuses on commercial buildings in China and applies a difference in differences model to evaluate the impact of BEESs on the CEE of commercial buildings.The slacks-based measure–data envelopment analysis model is employed to assess the CEE of commercial buildings in 30 Chinese provinces from 2000 to 2019.Furthermore,heterogeneous tests are used to explore how climate characteristics and economic conditions affect the efficiency of BEESs.The results indicate that BEESs positively influence the CEE of commercial buildings.Specifically,a 1%increase in the intensity of BEESs causes a 0.1484%increase in the CEE of commercial buildings.Moreover,the impact of BEESs is particularly pronounced in the southern and western provinces.This study provides valuable scientific evidence for governments to enhance BEESs implementation.
基金supported by the National Key Research and Development Program of China(2023YFF1304304)。
文摘Tibetan alpine steppes are large and sensitive terrestrial carbon(C)reservoirs that are experiencing desertification due to global change and overgrazing,which can lead to stronger resource limitations for both above-and belowground communities.Soil nutrients,especially nitrogen(N)and phosphorus(P),are the crucial resources for plant growth and microbial metabolism.However,whether both plant and soil microbial communities in the degraded alpine steppes are limited by these soil nutrients remains unclear,which limits our understanding of the mechanisms of desertification and subsequent ecosystem restoration.Here,we evaluated potential nutrient limitations of the plant and soil microbial communities in the alpine steppe across five stages of desertification using stoichiometry-based approaches.Our results showed that soil microbial metabolism was mainly limited by C and P,and the plant N limitation and microbial C limitation were intensified while the microbial P limitation was relieved during desertification.Plant-soil-microbe interactions had significant impacts on the microbial C and P limitations,explaining 72 and 61%of the variation,respectively.Specifically,desertification ultimately affected microbial metabolic limitations by regulating soil pH,soil nutrients,and the plant N limitation.Moreover,the microbial C limitation further reduced microbial C use efficiency(CUE)with desertification,which is detrimental for organic C retention in the degraded soil.Overall,this study revealed that microbial metabolic limitations through plant-microbe interactions were the key drivers affecting soil microbial CUE,and it provided insights that can advance our knowledge of the microbial regulation of nutrient cycles and C sequestration.
基金funded by the National Natural Science Foundation of China(Nos.42173059 and 41991322)。
文摘Enhanced silicate weathering(ESW)is a geoengineering method aimed at accelerating carbon dioxide(CO_(2))removal(CDR)from atmosphere by increasing the weathering flux of silicate rocks and minerals.It has emerged as a promising strategy for CDR.Theoretical studies underscore ESW’s substantial potential for CDR and its diverse benefits for crops when applied to croplands.However,the well-known significant discrepancies in silicate weathering rates between laboratory and field conditions introduce uncertainty in CDR through ESW.By compiling data from recent literature,we calculated and compared CDR efficiency(t CO_(2)t^(-1)_(silicate)ha^(-1)y^(-1))observed in mesocosm experiments and field trials.The findings indicate that CDR efficiencies in field trials are comparable to or exceeding that observed in mesocosm experiments by 1-3 orders of magnitude,particularly evident with wollastonite application.The hierarchy of CDR efficiency among silicates suitable for ESW is ranked as follows:olivine≥wollastonite>basalt>albite≥anorthite.We suggest the potential role of biota,especially fungi,in contributing to higher CDR efficiencies observed in field trials compared to mesocosm experiments.We further emphasize introducing fungi known for their effectiveness in silicate weathering could potentially enhance CDR efficiency through ESW in croplands.But before implementing fungal-facilitated ESW,three key questions need addressing:(i)How does the community of introduced fungi evolve over time?(ii)What is the long-term trajectory of CDR efficiency following fungal introduction?and(iii)Could fungal introduction lead to organic matter oxidation,resulting in elevated CO_(2)emissions?These investigations are crucial for optimizing the efficiency and sustainability of fungal-facilitated ESW strategy.
基金The work described in this paper was supported by China Postdoctoral Science Foundation(Grant No.2018M642935)the Plateau Disciplines in Shanghai,and the National Natural Science Foundation of China(Grant Nos.51905392,51775392 and 51675388)These financial contributions are gratefully acknowledged.
文摘Low-carbon manufacturing(LCM)is increasingly being regarded as a new sustainable manufacturing model of carbon emission reduction in the manufacturing industry.In this paper,a two-stage low-carbon scheduling optimization method of job shop is presented as part of the efforts to implement LCM,which also aims to reduce the processing cost and improve the efficiency of a mechanical machining process.In the first stage,a task assignment optimization model is proposed to optimize carbon emissions without jeopardizing the processing efficiency and the profit of a machining process.Non-dominated sorting genetic algorithm II and technique for order preference by similarity to an ideal solution are then adopted to assign the most suitable batch task of different parts to each machine.In the second stage,a processing route optimization model is established to plan the processing sequence of different parts for each machine.Finally,niche genetic algorithm is utilized to minimize the makespan.A case study on the fabrication of four typical parts of a machine tool is demonstrated to validate the proposed method.
基金Project of Basic Work of Science and Technology of Guizhou Provincial Science and Technology Department in 2020,“Quantification of Ecological Compensation in Southwest China Based on Carbon Balance”[Grant number.Guizhou Science Cooperation Basic Project[2020]1Y287]Research Fund Project of Guizhou University of Finance and Economics in 2020,“Research on the Influencing Factors of China's Low-carbon Trade Competitiveness”[Grant number.2020XJC01].
文摘Based on the input-output data from 2002 to 2017,this paper combined the three-stage DEA model with the non-competitive I-O model and measured the embodied carbon efficiency of export trade in China’s 26 product sectors,and further investigated its influencing factors and convergence issues.The results of the study showed that:①The embodied carbon efficiency of export trade in China’s overall product sector demonstrated a positive development trend from 2002 to 2017,and this positive trend was more obvious after the implementation of conservation culture construction in 2012.But the differences of embodied carbon emission efficiency level among the product sectors were still significant.②Measured by the K-means clustering analysis method,this study found that agriculture,other service industries,wholesale and retail industries,catering industry,construction industry and manufacturing industry with strong innovation ability were mostly concentrated at high and medium efficiency levels,while industrial sectors with resource dependence and high energy consumption,such as metal smelting and rolling processing industries,non metallic mineral products industry,and coal mining industry,were at a low efficiency level.③All product sectors hadσconvergence,absoluteβconvergence and conditionalβconvergence during 2002-2010 and 2010-2017,and the level of each product sector in 2010-2017 was higher than that in 2002-2010 according to the perspective of convergence speed and degree of convergence.④Technological progress had not fully played a role in suppressing energy consumption and improving the efficiency of embodied carbon efficiency,and it would also widen the gap between the embodied carbon emission efficiency levels of various product sectors.The expansion of trade scale could effectively improve carbon emission efficiency and narrow the gap between sectors.Environmental regulation could effectively promote the improvement of embodied carbon emission efficiency but would widen the level gap between sectors.These findings indicate that China needs to build a sound environmental regulation system for the development of low-carbon trade,continue to reasonably expand the scale of trade,eliminate backward industries with production capacity,vigorously develop low-carbon technologies such as new energy,strengthen the exchange of low carbon technologies and industrial cooperation among sectors,and promote coordinated development among industries.
基金jointly supported by the Fundamental Research Funds for the Central Universities(XDJK2019B074)the National Natural Science Foundation of China(51822906)the National Key Research and Development Project(2017YFC1502405)。
文摘Understanding of the vegetation dynamics is essential for addressing the potential threats of terrestrial ecosystem.In recent years,the vegetation coverage of the Yangtze River Basin(YRB)has increased significantly,yet the spatio-temporal variations and potential driving meteorological factors of carbon use efficiency(CUE)under the context of global warming are still not clear.In this study,MODIS-based public-domain data during 2000–2015 was used to analyze these aspects in the YRB,a large river basin with powerful ecological functions in China.Spatio-temporal variations of CUE in different sub-basins and land cover types were investigated and the correlations with potential driving meteorological factors were examined.Results revealed that CUE in the YRB had strong spatiotemporal variability and varied remarkably in different land cover types.For the whole YRB,the average CUE of vegetated land was 0.519,while the long-term change trend of CUE was obscure.Along the rising altitude,CUE generally showed an increasing trend until the altitude of 3900 m and then followed by a decreasing trend.CUE of grasslands was generally higher than that of croplands,and then forest lands.The inter-annual variation of CUE in the YRB is likely to be driven by precipitation as a strong positive partial correlation between the inter-annual variability of CUE and precipitation was observed in most of sub-basins and land cover types in the YRB.The influence of temperature and relative humidity is also outstanding in certain regions and land cover types.Our findings are useful from the view point of carbon cycle and reasonable land cover management under the context of global warming.
文摘To quantitatively address the role of tissue N in crop respiration under various agricultural practices, and to consequently evaluate the impact of synthetic fertilizer N application on biomass production and respiration, and hence net carbon fixation efficiency （Encf）, pot and field experiments were carried out for an annual rotation of a rice-wheat cropping system from 2001 to 2003. The treatments of the pot experiments included fertilizer N application, sowing date and planting density. Different rates of N application were tested in the field experiments. Static opaque chambers were used for sampling the gas. The respiration as CO2 emission was detected by a gas chromatograph. A successive biomass clipping method was employed to determine the crop autotrophic respiration coefficient （Ra）. Results from the pot experiments revealed a linear relationship between Ra and tissue N content as Ra = 4.74N-1.45 （R^2= 0.85, P 〈 0.001）. Measurements and calculations from the field experiments indicated that fertilizer N application promoted not only biomass production but also increased the respiration of crops. A further investigation showed that the increase of carbon loss in terms of respiration owing to fertilizer N application exceeded that of net carbon gain in terms of aboveground biomass when fertilizer N was applied over a certain rate. Consequently, the Encf declined as the N application rate increased.
基金This research was funded by the National Science Foundation under the Project“Synergic evolution mechanism of intercity transportation and metropolitan tourism spatial pattern”[Grant number.41771162]It was also funded by the National First-Class Discipline Development Project in Hunan Province under the category of“Geography”[Grang number.510002].
文摘Grasping the spatial correlation structure of transportation carbon emission efficiency(TCEE)and its influencing factors is significant for promoting high-quality and coordinated development of the transportation industry and the relevant region.Based on the ideal point cross-efficiency(IPCE)model,the social network analysis method was employed herein to explore the spatial correlation network structure of China’s provincial TCEE and its influencing factors.The results obtained showed the following outcomes.(1)During the study period,China’s provincial TCEE formed a complex and multithreaded network association relationship,but its network association structure was still relatively loose and presented the hierarchical gradient characteristics of dense in the east and sparse in the west.(2)The correlation of China’s TCEE formed a block segmentation based on the regional boundaries,and its factional structure was relatively obvious.The eastern region was closely connected with the central region,and generally connected with the western and northeastern regions.The central region was mainly connected with the eastern and western regions,and relatively less connected with the northeastern region.Besides,the northeastern region was weakly connected with the western region.(3)Shanghai,Beijing,Zhejiang,Guangdong,Jiangsu,Tianjin,and other developed provinces were in the core leading position in the TCEE network,which significantly impacted the spatial correlation of TCEE.However,Heilongjiang,Jilin,Xinjiang,Qinghai,and other remote provinces in the northeast and northwest were at the absolute edge of the network,which weakly impacted the spatial correlation of TCEE.(4)Provincial distance,economic development-level difference,transportation intensity difference,and transportation structure difference had significant negative impacts on the spatial correlation network of China’s provincial TCEE.In contrast,the energy-saving technology level difference had a significant positive impact on it.The regression coefficients of transportation energy structure and environmental regulation differences were positive but insignificant;their response mechanism and effects need to be improved and enhanced.
文摘This paper uses an input-output table of China's provinces(2007-2016)to measure carbon emissions of these industries.It employs a Malmquist-Luenberger(ML)index with expected and undesired outputs,and an absoluteβconvergence and a conditionalβconvergence model,to conduct an in-depth analysis of dynamic changes and spatial convergence.Carbon emission efficiency of forest processing industries in 25 regions,including Shanghai,Chongqing,Zhejiang,and Jiangsu are increasing,whereas those of Tianjin,Liaoning,Heilongjiang,and Xizang are decreasing.The main contributing factors of carbon emission efficiency in three major regions vary over time.Further,carbon emission efficiency in the eastern,central,and western regions all have absoluteβconvergence and conditionalβconvergence,indicating that different regions are developing toward their own goals and industry,yet regions with lower efficiency are catching up with those where with more efficient strategies in place.Finally,this paper proposes according recommendations.
文摘To measure the carbon emission efficiency of China’s pharmaceutical manufacturing industry, explore the factors affecting the carbon emission efficiency of China’s pharmaceutical manufacturing industry, and provide reference for improving the carbon emission efficiency of China’s pharmaceutical manufacturing industry and promoting the government to formulate macro policies. Based on the data of the pharmaceutical manufacturing industry in 30 provinces of China from 2010 to 2019, and based on the SBM model and ML (Malmquist-Luenberger) index model, the carbon emission efficiency of the pharmaceutical manufacturing industry was calculated and its dynamic change was investigated, and the Tobit model was further used to explore the influencing factors of the carbon emission efficiency of the pharmaceutical manufacturing industry. The carbon emission efficiency of China’s inter-provincial pharmaceutical manufacturing industry has steadily improved. The carbon emission efficiency of the eastern region is higher than that of the western region, and that of the western region is higher than that of the central region. The eastern region is dominated by technological progress, and there is room for improvement in technological efficiency. The central and western regions are dominated by technological efficiency. Compared with technological efficiency, technological progress needs to be further improved. Environmental regulation, industrial agglomeration and technological innovation level positively affect carbon emission efficiency, while foreign investment level has no significant impact on carbon emission efficiency.
基金supported by the key project of the National Natural Science Foundation of China(No.51034005)the Research Fund for the Doctoral Program of Higher Education(the Specialized Research Fund for the Doctoral Program of Higher Education of China)(No.20100095110019)+1 种基金the National‘‘Twelfth Five-Year’’Plan for Science&Technology Support(No.2014BAC14B00)the National High Technology Research and Development Program of China(No.2012AA062004)
文摘Transportation accounts for 80% of open-cut coal mine carbon emissions. With regard to the energy con- sumption and carbon emissions of transportation within an open-cut mine, this paper systematically compared the work and energy consumption of a truck and belt conveyor on a theoretical basis, and con- structed a model to calculate the energy consumption of open-cut mine transportation. Life cycle carbon emission factors and power consumption calculation model were established through a Process Analysis- Life Cycle Analysis （PA-LCA）. The following results were obtained： （1） the energy consumption of truck transportation was four to twelve times higher than that of the belt conveyor; （2） the C02 emissions from truck transportation were three to ten times higher than those of the belt conveyor; （3） with the increase in the slope angle for transportation, the ratio of truck to belt conveyor for both energy consumption and carbon emissions gradually decreased; （4） based on 2013 prices in China, the energy cost of transportation using a belt conveyor in open-cut coal mines could save 0.6-2.4 Yuan/（t kin） compared to truck transportation.
基金supported by the Science Fund for Distinguished Young Scholars in the Xinjiang Uygur Autonomous Region (QN2015JQ007)
文摘Water-use efficiency（WUE） is a key plant functional trait that plays a central role in the global cycles of water and carbon. Although increasing precipitation may cause vegetation changes, few studies have explored the linkage between alteration in vegetation and WUE. Here, we analyzed the responses of leaf WUE, ecosystem carbon and water exchanges, ecosystem WUE, and plant community composition changes under normal conditions and also under extra 15% or 30% increases in annual precipitation in a temperate desert ecosystem of Xinjiang, China. We found that leaf WUE and ecosystem WUE showed inconsistent responses to increasing precipitation. Leaf WUE consistently decreased as precipitation increased. By contrast, the responses of the ecosystem WUE to increasing precipitation are different in different precipitation regimes： increasing by 33.9% in the wet year（i.e., the normal precipitation years）and decreasing by 4.1% in the dry year when the precipitation was about 30% less than that in the wet year.We systematically assessed the herbaceous community dynamics, community composition, and vegetation coverage to explain the responses of ecosystem WUE, and found that the between-year discrepancy in ecosystem WUE was consistent with the extent to which plant biomass was stimulated by the increase in precipitation. Although there was no change in the relative significance of ephemerals in the plant community, its greater overall plant biomass drove an increased ecosystem WUE under the conditions of increasing precipitation in 2011. However, the slight increase in plant biomass exerted no significant effect on ecosystem WUE in 2012. Our findings suggest that an alteration in the dominant species in this plant community can induce a shift in the carbon-and water-based economics of desert ecosystems.
基金supported by the Natural Science Foundation of China (No.41401044 and No.41310013)the key research projects of frontier sciences CAS (QYZDJ-SSW-DQC006)+1 种基金the Chinese Academy of Science (‘West Star’ project)the CAS/SAFEA international partnership program for creative research teams (KZZD-EW-TZ-06)
文摘Abies fabri is a typical subalpine dark coniferous forest in southwestern China. Air temperature increases more at high elevation areas than that at low elevation areas in mountainous regions,and climate change ratio is also uneven in different seasons. Carbon gain and the response of water use efficiency(WUE) to annual and seasonal increases in temperature with or without CO_2 fertilization were simulated in Abies fabri using the atmospheric-vegetation interaction model(AVIM2). Four future climate scenarios(RCP2.6,RCP4.5,RCP6.0 and RCP8.5) from the Coupled Model Intercomparison Project Phase 5(CMIP5) were selectively investigated. The results showed that warmer temperatures have negative effects on gross primary production(GPP) and net primary production(NPP) in growing seasons and positive effects in dormant seasons due to the variation in the leaf area index. Warmer temperatures tend to generate lower canopy WUE and higher ecosystem WUE in Abies fabri. However,warmer temperature together with rising CO_2 concentrations significantlyincrease the GPP and NPP in both growing and dormant seasons and enhance WUE in annual and dormant seasons because of the higher leaf area index(LAI) and soil temperature. The comparison of the simulated results with and without CO_2 fertilization shows that CO_2 has the potential to partially alleviate the adverse effects of climate warming on carbon gain and WUE in subalpine coniferous forests.
基金the National Natural Science Foundation of China(41730638)the Key Research and Development Program of Shaanxi Province,China(2021ZDLSF05-02)+2 种基金the Scientific and Technological Innovation Project of Shaanxi Forestry Academy of Sciences,China(SXLK2021-0206)the Funding of Special Support Plan of Young Talents Project in China(2021)the National Forestry and Grassland Administration in China(20201326015).
文摘Manipulated precipitation patterns can profoundly influence the metabolism of soil microorganisms.However,the responses of soil organic carbon(SOC)and nutrient turnover to microbial metabolic limitation under changing precipitation conditions remain unclear in semi-arid ecosystems.This study measured the potential activities of enzymes associated with carbon(C:β-1,4-glucosidase(BG)andβ-D-cellobiosidase(CBH)),nitrogen(N:β-1,4-N-acetylglucosaminidase(NAG)and L-leucine aminopeptidase(LAP))and phosphorus(P:alkaline phosphatase(AP))acquisition,to quantify soil microbial metabolic limitations using enzymatic stoichiometry,and then identify the implications for soil microbial metabolic limitations and carbon use efficiency(CUE)under decreased precipitation by 50%(DP)and increased precipitation by 50%(IP)in a temperate grassland.The results showed that soil C and P were the major elements limiting soil microbial metabolism in temperate grasslands.There was a strong positive dependence between microbial C and P limitations under manipulated precipitation.Microbial metabolism limitation was promoted by DP treatment but reversed by IP treatment.Moreover,CUE was inhibited by DP treatment but promoted by IP treatment.Soil microbial metabolism limitation was mainly regulated by soil moisture and soil C,N,and P stoichiometry,followed by available nutrients(i.e.,NO^(-)_(3),NH^(+)_(4),and dissolved organic C)and microbial biomass(i.e.,MBC and MBN).Overall,these findings highlight the potential role of changing precipitation in regulating ecosystem C turnover by limiting microbial metabolism and CUE in temperate grassland ecosystems.
基金the University of Helsinki three-year Grant(Decision number HY/66/05.01.07/2017)Helsinki Institute of Life Science(HiLIFE Fellow grant to KK),and Academy of Finland(Grant number 316401).
文摘Biochar has been widely recognized for its potential to increase carbon(C)sequestration and mitigate climate change.This potential is affected by how biochar interacts with native soil organic carbon(SOC)and fresh organic substrates added to soil.However,only a few studies have been conducted to understand this interaction.To fill this knowledge gap,we conducted a ^(13)C-glucose labelling soil incubation for 6 months using fine-textured agricultural soil(Stagnosol)with two different biochar amounts.Biochar addition reduced the mineralization of SOC and ^(13)C-glucose and increased soil microbial biomass carbon(MBC)and microbial carbon use efficiency(CUE).The effects were found to be additive i.e.,higher biochar application rate resulted in lower mineralization of SOC and ^(13)C-glucose.Additionally,soil density fractionation after 6 months revealed that most of the added biochar particles were recovered in free particulate organic matter(POM)fraction.Biochar also increased the retention of ^(13)C in free POM fraction,indicating that added ^(13)C-glucose was preserved within the biochar particles.The measurement of ^(13)C from the total amino sugar fraction extracted from the biochar particles suggested that biochar increased the microbial uptake of added ^(13)C-glucose and after they died,the dead microbial residues(necromass)accumulated inside biochar pores.Biochar also increased the proportion of occluded POM,demonstrating that increased soil occlusion following biochar addition reduced SOC mineralization.Overall,the study demonstrates the additional C sequestering potential of biochar by inducing negative priming of native SOC as well as increasing CUE,resulting in the formation and stabilization of microbial necromass.
