The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.Howev...The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.However,few studies have quantified the effects of these factors on the main quality components of tea.The study aimed to explore the interactions of C,N,and P in soil-microorganisms-plants and the effects of these factors on the main quality components of tea by using the path analysis method.The results indicated that(1)The contents of C,N,and P in soil,microorganisms,and tea plants were highly correlated and collinear,and showed significant correlations with the main quality components of tea.(2)Optimal regression equations were established to esti-mate tea polyphenol,amino acid,catechin,caffeine,and water extract content based on C,N,and P contents in soil,microorganisms,and tea plants(R^(2)=0.923,0.726,0.954,0.848,and 0.883,respectively).(3)Pathway analysis showed that microbial biomass phosphorus(MBP),root phosphorus,branch nitrogen,and microbial biomass carbon(MBC)were the largest direct impact factors on tea polyphenol,catechin,water extracts,amino acid,and caffeine content,respectively.Leaf carbon,root phosphorus,and leaf nitrogen were the largest indirect impact factors on tea polyphenol,catechin,and water extract content,respectively.Leaf carbon indirectly affected tea polyphenol content mainly by altering MBP content.Root phosphorus indirectly affected catechin content mainly by altering soil organic carbon content.Leaf nitrogen indirectly affected water extract content mainly by altering branch nitrogen content.The research results provide the scientific basis for reasonable fertilization in tea gardens and tea quality improvement.展开更多
Irrigated agriculture has tripled since 1950,accounting for 20%of the global arable land and 40%of food production.Irrigated agriculture increases food security yet has controversial implications for global climate ch...Irrigated agriculture has tripled since 1950,accounting for 20%of the global arable land and 40%of food production.Irrigated agriculture increases food security yet has controversial implications for global climate change.Most previous studies have calculated carbon emissions and their composition in irrigated areas using the engineering approach to life-cycle assessment.By combining life cycle assessment(LCA)-based carbon emissions accounting with econometric models such as multiple linear regression and structural equation modeling(SEM),we conducted an interdisciplinary study to identify the influencing factors and internal mechanisms of the carbon footprint(CFP)of smallholder crop cultivation on irrigation reform pilot areas.To this end,we investigated corn and potato production data in the 2019–2020 crop years for 852 plots of 345 rural households in six villages(two irrigation agriculture pilot villages and four surrounding villages as controls)in Southwest China.The crop CFP in the irrigation agriculture pilot areas was significantly lower than in non-reform areas.Irrigation reforms mainly impacted the crop CFP through four intermediary effects:the project(implementation of field irrigation channels),technology(improving adoption of new irrigation technologies),management(proper irrigation operation and maintenance),and yield effects.All effects inhibited the CFP,except for the project effect that promotes carbon emissions.Among them,yield increase has the greatest impact on reducing CFP,followed by management and technology effects.Furthermore,planting practices,individual characteristics,and plot quality significantly impacted the crop CFP.This study has policy implications for understanding the food security–climate nexus in the food production industry.展开更多
Dry sliding friction and wear test of Nb containing low carbon microalloyed steel was carried out at room temperature,and the effect of Nb on the wear behavior of the steel,as welll as the mechanism was studied.Scanni...Dry sliding friction and wear test of Nb containing low carbon microalloyed steel was carried out at room temperature,and the effect of Nb on the wear behavior of the steel,as welll as the mechanism was studied.Scanning electron microscopy(SEM) and energy dispersive spectrometry(EDS) were employed to analyze the morphology and composition of the worn surface,and the structure evolution of the plastic deformation layer.The carbide content and type in the steel were analyzed by the electrolytic extraction device and X-ray diffraction(XRD).The experimental results demonstrate that the addition of 0.2% Nb can refine the grain and generate Nb C to improve the wear resistance of the steel.By enhancing the load and speed of wear experiment,the wear mechanism of the test steel with 0.2% Nb changes from slight oxidation wear to severe adhesion wear and oxidation wear.Compared with the load,the increase in the rotation speed exerts a greater influence on the wear of the test steel.展开更多
The construction of relevant standards for building carbon emission assessment in China has just started,and the quantitative analysis method and evaluation system are still imperfect,which hinders the development of ...The construction of relevant standards for building carbon emission assessment in China has just started,and the quantitative analysis method and evaluation system are still imperfect,which hinders the development of low-carbon building design.Therefore,the use of intelligent energy management system is very necessary.The purpose of this paper is to explore the design optimization of low-carbon buildings based on intelligent energy management systems.Based on the proposed quantitative method of building carbon emission,this paper establishes the quota theoretical system of building carbon emission analysis,and develops the quota based carbon emission calculation software.Smart energy management system is a low-carbon energy-saving system based on the reference of large-scale building energy-saving system and combined with energy consumption.It provides a fast and effective calculation tool for the quantitative evaluation of carbon emission of construction projects,so as to realize the carbon emission control and optimization in the early stage of architectural design and construction.On this basis,the evaluation,analysis and calculation method of building structure based on carbon reduction target is proposed,combined with the carbon emission quota management standard proposed in this paper.Taking small high-rise residential buildings as an example,this paper compares and analyzes different building structural systems from the perspectives of structural performance,economy and carbon emission level.It provides a reference for the design and evaluation of low-carbon building structures.The smart energy management system collects user energy use parameters.It uses time period and time sequence to obtain a large amount of data for analysis and integration,which provides users with intuitive energy consumption data.Compared with the traditional architectural design method,the industrialized construction method can save 589.22 megajoules(MJ)per square meter.Based on 29270 megajoules(MJ)per ton of standard coal,the construction area of the case is about 8000 m2,and the energy saving of residential buildings is 161.04 tons of standard coal.This research is of great significance in reducing the carbon emission intensity of buildings.展开更多
On the basis of existing research,carbon emission reduction technologies in production,processing,packaging,transportation and storage of the food system were summarized,and their application effects were analyzed.In ...On the basis of existing research,carbon emission reduction technologies in production,processing,packaging,transportation and storage of the food system were summarized,and their application effects were analyzed.In view of the inherent inadequacy of carbon emission reduction technologies in Chinese food system,starting from carbon labeling technologies and ESG system of the food industry,the unsoundness of the carbon emission reduction evaluation system and the high cost of related technology promotion,countermeasures such as strengthening top-level design,encouraging and supporting the development of new carbon emission reduction technologies,and improving carbon emission reduction technology subsidies were proposed by drawing on domestic and international experiences.展开更多
Through interpreting significance of low-carbon landscape, and analyzing common problems in landscape design industry, paths of low-carbon landscape design were explored from the following perspectives: establishing l...Through interpreting significance of low-carbon landscape, and analyzing common problems in landscape design industry, paths of low-carbon landscape design were explored from the following perspectives: establishing low-carbon index system for the landscape construction of eco-city; constructing scientific and reasonable spatial layout; using landscapes to interpret low-carbon concepts; enhancing the carbon sink function of urban green spaces; choosing reasonable landscape materials; reducing landscape maintenance cost. The study aims at applying low-carbon concepts in all design projects to achieve sustainable development of urban landscapes.展开更多
Low carbon landscape development is an emerging approach of landscape design,which aims to promote sustainable development,and reduce energy consumption and environmental impact by reducing carbon emissions.As an impo...Low carbon landscape development is an emerging approach of landscape design,which aims to promote sustainable development,and reduce energy consumption and environmental impact by reducing carbon emissions.As an important component of low carbon landscape construction,the construction of urban pocket park system based on mini-parks plays a crucial role in improving the urban greening level,increasing the urban green space,alleviating the urban pressure,improving the living and healthy environment of urban residents,and promoting the urban ecological balance.Taking Chaowai district of Beijing as an example,this paper calculates the ecological value of trees including energy contribution,carbon sequestration,ability to improve rainfall runoff and aesthetic value by collecting the information of trees and the plot on which the trees are located through the i-Tree platform,which provides important reference value for the urban pocket park system planning to create low carbon comprehensive benefits.展开更多
This study develops a comprehensive analysis framework and socio-economic energy system model that interlinks demographic change and energy system in order to analyze the urbanization process and its relation with Chi...This study develops a comprehensive analysis framework and socio-economic energy system model that interlinks demographic change and energy system in order to analyze the urbanization process and its relation with China's long-term CO2 emissions trend as China'economy enters the“new normal”stage.The results show that,around 300 million people are expected to migrate from rural areas to urban areas by 2050 following a trend,in which people are moving gradually from small and medium city groups to large and super city groups.The migration trend together with the improvement in living standard will promote China's infrastructure construction,industry production,and energy service demand growth.Under the Business as Usual(BAU)scenario,total primary energy consumption in China will reach 8.4 Gtce by 2050,energyrelated CO2 emissions will increase to 17.6 Gt,which is 83%higher than the 2013 level.While in the Low Carbon Transition(LCT)scenario with technology innovation,the total primary energy demand for China in 2050 could be controlled at^6 Gtce;CO2 emissions would peak during 2020—2025,and be reduced by 78%by 2050 compared to the BAU scenario.In the transition process,non-fossil fuel power generation and energy efficiency technologies have the largest mitigation potentials.Industry and power sectors would peak first before 2020,followed by the building and transport sectors which are projected to peak around 2030.The total additional capital investment required for LCT would account for 1.5%of GDP.Therefore,it is technologically and economically feasible for China to implement new urbanization strategy.展开更多
Consolidating carbon sink capacity and reducing carbon pressure are important channels to achieve the carbon peaking and carbon neutrality goals actively yet prudently.In order to study the current situation of carbon...Consolidating carbon sink capacity and reducing carbon pressure are important channels to achieve the carbon peaking and carbon neutrality goals actively yet prudently.In order to study the current situation of carbon pressure in the Northwestern Sichuan,we took the carbon pressure of the Aba Tibetan-Qiang autonomous prefecture(Aba prefecture)as an example and used the Intergovernmental Panel on Climate Change(IPCC)approach to measure the carbon emissions,carbon uptake,and the carbon balance index(CBI)of each county-level city in Aba prefecture from 2012 to 2020.The study found that:(a)There was a continuous trend of declining carbon emissions,increased carbon uptake,and decreased CBI in Aba prefecture during the sample period,but there is a large variability among county-level cities;(b)Aba prefecture differs in the spatiotemporal distribution of carbon emissions,carbon uptake,and CBI.Based on the research results,we propose several optimized paths for alleviating the current carbon pressure situation in the Northwestern Sichuan.展开更多
Considering the growing prominence of global environmental issues,a low-carbon economy has emerged as a crucial direction for economic development across various countries.As the world’s second-largest economy,China ...Considering the growing prominence of global environmental issues,a low-carbon economy has emerged as a crucial direction for economic development across various countries.As the world’s second-largest economy,China has also witnessed the influence of a low-carbon economy on its international trade development.This article aims to commence with an exploration of the development background,meaning,and significance of a low-carbon economy.Subsequently,it delves into an in-depth analysis of the impact that a low-carbon economy has on China’s international trade.The article concludes by proposing pertinent countermeasures and suggestions.展开更多
With the continuous implementation of national measures related to carbon neutrality strategy,the concept of a low-carbon economy has been deeply rooted in people’s hearts.Low-carbon tourism has gradually become an i...With the continuous implementation of national measures related to carbon neutrality strategy,the concept of a low-carbon economy has been deeply rooted in people’s hearts.Low-carbon tourism has gradually become an inevitable trend,and the tourism industry is also undergoing orderly transformation and upgrading.To promote the sustainable development of the tourism industry,the tourism and hotel industry should also shift towards a low-carbon and green model.Hotel activities can easily bring related environmental issues,such as energy consumption,garbage generation,ecological pollution,etc.Therefore,building a green hotel will bring huge social and economic benefits to the low-carbon tourism industry.This article will address the above issues and take a low-carbon economy as the starting point,proposing sustainable development strategies and suggestions for green hotels from both the internal and external environment of the hotel,creating a low-carbon management atmosphere,and promoting the low-carbon operation of the green hotel industry.展开更多
Global warming threatens the lives and development of human beings and has become one of the major challenges tohumanity in the 21st century.With China’s continuous economic strengthening and closer contact with the ...Global warming threatens the lives and development of human beings and has become one of the major challenges tohumanity in the 21st century.With China’s continuous economic strengthening and closer contact with the world economy,prospects of China’s energy demands,energy supply roadmap and related carbon emissions have become the focus ofvarious organizations.By applying a scenario analysis,this report analyzes and forecasts China’s energy demands andcarbon emissions trends over the coming thirty to fifty years.Results indicate that under certain conditions,it will bepossible for China to take on a low carbon development path with Chinese characteristics.However,China needs overalladjustments in policy,institutions,structure,technology as well as strong support from international economic andpolitical environments.展开更多
A suitable carburized microstructure with fine granular dispersed carbides in hypereutectoidzone,ultra fine martensite in matrix and recrystallized austenite to be refined to the grain size of 12～14 hasbeen obtained ...A suitable carburized microstructure with fine granular dispersed carbides in hypereutectoidzone,ultra fine martensite in matrix and recrystallized austenite to be refined to the grain size of 12～14 hasbeen obtained by a new process,which is a high carbon concentration carburizing with rare earth element atlow temperature(860～880℃)in a discontinuous gas carburization furnace.There was not much differencefor the microstructure in eutectic zone between this and conventional process.Forming mechanism ofgranular carbides has been also studied in this paper.展开更多
During the production of Ti-bearing Al-killed ultra-low-carbon(ULC) steel, two different heating processes were used when the converter tapping temperature or the molten steel temperature in the Ruhrstahl–Heraeus(RH)...During the production of Ti-bearing Al-killed ultra-low-carbon(ULC) steel, two different heating processes were used when the converter tapping temperature or the molten steel temperature in the Ruhrstahl–Heraeus(RH) process was low: heating by Al addition during the RH decarburization process and final deoxidation at the end of the RH decarburization process(process-Ⅰ), and increasing the oxygen content at the end of RH decarburization, heating and final deoxidation by one-time Al addition(process-Ⅱ). Temperature increases of 10°C by different processes were studied; the results showed that the two heating processes could achieve the same heating effect. The T.[O] content in the slab and the refining process was better controlled by process-Ⅰ than by process-Ⅱ. Statistical analysis of inclusions showed that the numbers of inclusions in the slab obtained by process-Ⅰ were substantially less than those in the slab obtained by process-Ⅱ. For process-Ⅰ, the Al_2O_3 inclusions produced by Al added to induce heating were substantially removed at the end of decarburization. The amounts of inclusions were substantially greater for process-Ⅱ than for process-Ⅰ at different refining stages because of the higher dissolved oxygen concentration in process-Ⅱ. Industrial test results showed that process-Ⅰ was more beneficial for improving the cleanliness of molten steel.展开更多
The microstructure evolution during deformation enhanced transformation of under cooled austenite of a plain low carbon steel has been investigated by means of hot compression simulation experiment under various condi...The microstructure evolution during deformation enhanced transformation of under cooled austenite of a plain low carbon steel has been investigated by means of hot compression simulation experiment under various conditions of strain rate,deforma- tion temperature and strain. The effect of austenite grain size on the strain enhanced ferrite transformation has been studied. The ferrite dynamic recrystallization involved in successive hot deformation has been explored.展开更多
The influence of hot deformation conditions on continuous cooling bainitic transformation has been investigated for a low carbon microalloyed steel. The CCT diagrams show that deformation in unrecrpstallized austcnite...The influence of hot deformation conditions on continuous cooling bainitic transformation has been investigated for a low carbon microalloyed steel. The CCT diagrams show that deformation in unrecrpstallized austcnite ation can accelerate transformation process. Bainitic transformation in intermediate transformation temperature region is prominent, and the proeutectoid polygonal ferrite transformation at evelated high temperature is suppressed. According to optical and TEM analyses, low carbon bainitic ferrite is characterized by granular and lathlike ferrite, based on the cooling rate and deformation conditions. For nondeformation, groaps of coarse parallel ferrite lath form from the prior austenite grain boundaries with the same crystallographic orientation. For heavy deformaton, cell structure within the austenite grains due to the high dislocation density formed, which provides more nucleation sites for bainite ferrite. So deformation can discontinue the growth of ferrite laths and decrease the length of ferrite laths.展开更多
Climate change is a common problem in human society.The Chinese government promises to peak carbon dioxide emissions by 2030 and strives to achieve carbon neutralization by 2060.The proposal of the goal of carbon peak...Climate change is a common problem in human society.The Chinese government promises to peak carbon dioxide emissions by 2030 and strives to achieve carbon neutralization by 2060.The proposal of the goal of carbon peak and carbon neutralization has led China into the era of climate economy and set off a green change with both opportunities and challenges.On the basis of expounding the objectives and specific connotation of China’s carbon peak and carbon neutralization,this paper systematically discusses the main implementation path and the prospect of China’s carbon peak and carbon neutralization.China’s path to realizing carbon neutralization includes four directions:(1)in terms of carbon dioxide emission control:energy transformation path,energy conservation,and emission reduction path;(2)for increasing carbon sink:carbon capture,utilization,and storage path,ecological governance,and land greening path;(3)in key technology development:zero-carbon utilization,coal new energy coupling,carbon capture utilization and storage(CCUS),energy storage technology and other key technology paths required to achieve carbon peak and carbon neutralization;(4)from the angle of policy development:Formulate legal guarantees for the government to promote the carbon trading market;Formulate carbon emission standards for enterprises and increase publicity and education for individuals and society.Based on practicing the goal and path of carbon peak and carbon neutralization,China will vigorously develop low carbon and circular economy and promote green and high-quality economic development;speed up to enter the era of fossil resources and promoting energy transformation;accelerate the integrated innovation of green and low-carbon technologies and promote carbon neutrality.展开更多
The characteristics of nanosized precipitates in steels depend on the heat-treatment parameters. The effects of characteristics of vanadium precipitates formed during isothermal heat treatment on the hardness of the f...The characteristics of nanosized precipitates in steels depend on the heat-treatment parameters. The effects of characteristics of vanadium precipitates formed during isothermal heat treatment on the hardness of the ferrite matrix in low-carbon vanadium-alloyed steel were investigated through analysis of transmission electron microscopy images and microhardness measurements. The results show that, during isothermal holding in the temperature range from 675 to 750℃, only interphase precipitation occurs, whereas only random precipitation occurs in the ferrite matrix during holding at 600℃. Furthermore, during isothermal heat treatment between 600 and 675℃, both random and interphase precipitates occurred in the ferrite. Nanoscale vanadium carbides with different atomic ratios of vanadium(V) and carbon(C) were the dominant precipitates in the random and interphase precipitates. The sizes of random precipitation carbides were smaller than those of interphase ones. Also, the sample isothermally heat treated at 650℃ for 900s exhibited a higher hardness with a narrower hardness distribution.展开更多
基金This work was supported by Guizhou Provincial Basic Research Program(Natural Science),Grant Number Qiankehejichu-ZK[2021]YB133Guizhou Provincial Scientific and Technological Program,Grant Number Qiankehehoubuzhu[2020]3001National Natural Science Foundation of China-Guizhou Provincial People’s Government Karst Science Research Centre(U1612442).
文摘The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.However,few studies have quantified the effects of these factors on the main quality components of tea.The study aimed to explore the interactions of C,N,and P in soil-microorganisms-plants and the effects of these factors on the main quality components of tea by using the path analysis method.The results indicated that(1)The contents of C,N,and P in soil,microorganisms,and tea plants were highly correlated and collinear,and showed significant correlations with the main quality components of tea.(2)Optimal regression equations were established to esti-mate tea polyphenol,amino acid,catechin,caffeine,and water extract content based on C,N,and P contents in soil,microorganisms,and tea plants(R^(2)=0.923,0.726,0.954,0.848,and 0.883,respectively).(3)Pathway analysis showed that microbial biomass phosphorus(MBP),root phosphorus,branch nitrogen,and microbial biomass carbon(MBC)were the largest direct impact factors on tea polyphenol,catechin,water extracts,amino acid,and caffeine content,respectively.Leaf carbon,root phosphorus,and leaf nitrogen were the largest indirect impact factors on tea polyphenol,catechin,and water extract content,respectively.Leaf carbon indirectly affected tea polyphenol content mainly by altering MBP content.Root phosphorus indirectly affected catechin content mainly by altering soil organic carbon content.Leaf nitrogen indirectly affected water extract content mainly by altering branch nitrogen content.The research results provide the scientific basis for reasonable fertilization in tea gardens and tea quality improvement.
基金financially supported by the Key Research and Development Program of Joint Research and Development Project Under the Sino–Thai Joint Committee on Science and Technology Cooperation(2017YFE0133000)the National Natural Science Foundation of China(72104239)+1 种基金the Fundamental Research Funds for Central Public Welfare Research Institutes,China(Y2022ZK03)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(ASTIP-IAED-2022-04)。
文摘Irrigated agriculture has tripled since 1950,accounting for 20%of the global arable land and 40%of food production.Irrigated agriculture increases food security yet has controversial implications for global climate change.Most previous studies have calculated carbon emissions and their composition in irrigated areas using the engineering approach to life-cycle assessment.By combining life cycle assessment(LCA)-based carbon emissions accounting with econometric models such as multiple linear regression and structural equation modeling(SEM),we conducted an interdisciplinary study to identify the influencing factors and internal mechanisms of the carbon footprint(CFP)of smallholder crop cultivation on irrigation reform pilot areas.To this end,we investigated corn and potato production data in the 2019–2020 crop years for 852 plots of 345 rural households in six villages(two irrigation agriculture pilot villages and four surrounding villages as controls)in Southwest China.The crop CFP in the irrigation agriculture pilot areas was significantly lower than in non-reform areas.Irrigation reforms mainly impacted the crop CFP through four intermediary effects:the project(implementation of field irrigation channels),technology(improving adoption of new irrigation technologies),management(proper irrigation operation and maintenance),and yield effects.All effects inhibited the CFP,except for the project effect that promotes carbon emissions.Among them,yield increase has the greatest impact on reducing CFP,followed by management and technology effects.Furthermore,planting practices,individual characteristics,and plot quality significantly impacted the crop CFP.This study has policy implications for understanding the food security–climate nexus in the food production industry.
文摘Dry sliding friction and wear test of Nb containing low carbon microalloyed steel was carried out at room temperature,and the effect of Nb on the wear behavior of the steel,as welll as the mechanism was studied.Scanning electron microscopy(SEM) and energy dispersive spectrometry(EDS) were employed to analyze the morphology and composition of the worn surface,and the structure evolution of the plastic deformation layer.The carbide content and type in the steel were analyzed by the electrolytic extraction device and X-ray diffraction(XRD).The experimental results demonstrate that the addition of 0.2% Nb can refine the grain and generate Nb C to improve the wear resistance of the steel.By enhancing the load and speed of wear experiment,the wear mechanism of the test steel with 0.2% Nb changes from slight oxidation wear to severe adhesion wear and oxidation wear.Compared with the load,the increase in the rotation speed exerts a greater influence on the wear of the test steel.
基金supported by“Key Technology Research on Operational Performance Improvement of the Green Building”(2020YFS0060)Key Project of Science and Technology Department of Sichuan Province+2 种基金supported by“Creative VR Teaching and Learning Research Based on‘PBL+’and Multidimensional Collaboration”(JG2021-721)“Reform in the Mode and Practice of Architecture Education with the Characteristics of Geology”(JG2021-672)Education Quality and Teaching Reform Project of Higher Education in Sichuan Province in 2021–2023.
文摘The construction of relevant standards for building carbon emission assessment in China has just started,and the quantitative analysis method and evaluation system are still imperfect,which hinders the development of low-carbon building design.Therefore,the use of intelligent energy management system is very necessary.The purpose of this paper is to explore the design optimization of low-carbon buildings based on intelligent energy management systems.Based on the proposed quantitative method of building carbon emission,this paper establishes the quota theoretical system of building carbon emission analysis,and develops the quota based carbon emission calculation software.Smart energy management system is a low-carbon energy-saving system based on the reference of large-scale building energy-saving system and combined with energy consumption.It provides a fast and effective calculation tool for the quantitative evaluation of carbon emission of construction projects,so as to realize the carbon emission control and optimization in the early stage of architectural design and construction.On this basis,the evaluation,analysis and calculation method of building structure based on carbon reduction target is proposed,combined with the carbon emission quota management standard proposed in this paper.Taking small high-rise residential buildings as an example,this paper compares and analyzes different building structural systems from the perspectives of structural performance,economy and carbon emission level.It provides a reference for the design and evaluation of low-carbon building structures.The smart energy management system collects user energy use parameters.It uses time period and time sequence to obtain a large amount of data for analysis and integration,which provides users with intuitive energy consumption data.Compared with the traditional architectural design method,the industrialized construction method can save 589.22 megajoules(MJ)per square meter.Based on 29270 megajoules(MJ)per ton of standard coal,the construction area of the case is about 8000 m2,and the energy saving of residential buildings is 161.04 tons of standard coal.This research is of great significance in reducing the carbon emission intensity of buildings.
基金Supported by the Fundamental Research Funds for the Central Universities(CZY23014)Major Project of the National Social Science Foundation(19ZDA085)。
文摘On the basis of existing research,carbon emission reduction technologies in production,processing,packaging,transportation and storage of the food system were summarized,and their application effects were analyzed.In view of the inherent inadequacy of carbon emission reduction technologies in Chinese food system,starting from carbon labeling technologies and ESG system of the food industry,the unsoundness of the carbon emission reduction evaluation system and the high cost of related technology promotion,countermeasures such as strengthening top-level design,encouraging and supporting the development of new carbon emission reduction technologies,and improving carbon emission reduction technology subsidies were proposed by drawing on domestic and international experiences.
基金Supported by Soft Science of Research Program of Tianjin Municipal Construction System (2012–Soft5)
文摘Through interpreting significance of low-carbon landscape, and analyzing common problems in landscape design industry, paths of low-carbon landscape design were explored from the following perspectives: establishing low-carbon index system for the landscape construction of eco-city; constructing scientific and reasonable spatial layout; using landscapes to interpret low-carbon concepts; enhancing the carbon sink function of urban green spaces; choosing reasonable landscape materials; reducing landscape maintenance cost. The study aims at applying low-carbon concepts in all design projects to achieve sustainable development of urban landscapes.
基金Sponsored by General Project of Natural Science Foundation of Beijing City(8202017)Youth Talent Support Program of 2018 Beijing Municipal University Academic Human Resources Development(PXM2018_014212_000043).
文摘Low carbon landscape development is an emerging approach of landscape design,which aims to promote sustainable development,and reduce energy consumption and environmental impact by reducing carbon emissions.As an important component of low carbon landscape construction,the construction of urban pocket park system based on mini-parks plays a crucial role in improving the urban greening level,increasing the urban green space,alleviating the urban pressure,improving the living and healthy environment of urban residents,and promoting the urban ecological balance.Taking Chaowai district of Beijing as an example,this paper calculates the ecological value of trees including energy contribution,carbon sequestration,ability to improve rainfall runoff and aesthetic value by collecting the information of trees and the plot on which the trees are located through the i-Tree platform,which provides important reference value for the urban pocket park system planning to create low carbon comprehensive benefits.
基金the China Postdoctoral Science Foundation(2019M650725)Shenzhen Low Carbon City Big Data Engineering Laboratory(ShenzhneDRC[2017]1089)Discipline Construction Program on Combating Climate Change and Low Carbon Economics of the Harbin Institute of Technology,Shenzhen,China(ShenzhenDRC[2018]725).
文摘This study develops a comprehensive analysis framework and socio-economic energy system model that interlinks demographic change and energy system in order to analyze the urbanization process and its relation with China's long-term CO2 emissions trend as China'economy enters the“new normal”stage.The results show that,around 300 million people are expected to migrate from rural areas to urban areas by 2050 following a trend,in which people are moving gradually from small and medium city groups to large and super city groups.The migration trend together with the improvement in living standard will promote China's infrastructure construction,industry production,and energy service demand growth.Under the Business as Usual(BAU)scenario,total primary energy consumption in China will reach 8.4 Gtce by 2050,energyrelated CO2 emissions will increase to 17.6 Gt,which is 83%higher than the 2013 level.While in the Low Carbon Transition(LCT)scenario with technology innovation,the total primary energy demand for China in 2050 could be controlled at^6 Gtce;CO2 emissions would peak during 2020—2025,and be reduced by 78%by 2050 compared to the BAU scenario.In the transition process,non-fossil fuel power generation and energy efficiency technologies have the largest mitigation potentials.Industry and power sectors would peak first before 2020,followed by the building and transport sectors which are projected to peak around 2030.The total additional capital investment required for LCT would account for 1.5%of GDP.Therefore,it is technologically and economically feasible for China to implement new urbanization strategy.
基金This paper is part of“A Study on the Spatiotemporal Evolution,Dilemma and Optimized Paths of Carbon Balance in Aba Prefecture Under the Carbon Peaking and Carbon Neutrality Goals”(ABKT2022065)a program funded by the Prefecture Social Science Fund Project of Aba Prefecture。
文摘Consolidating carbon sink capacity and reducing carbon pressure are important channels to achieve the carbon peaking and carbon neutrality goals actively yet prudently.In order to study the current situation of carbon pressure in the Northwestern Sichuan,we took the carbon pressure of the Aba Tibetan-Qiang autonomous prefecture(Aba prefecture)as an example and used the Intergovernmental Panel on Climate Change(IPCC)approach to measure the carbon emissions,carbon uptake,and the carbon balance index(CBI)of each county-level city in Aba prefecture from 2012 to 2020.The study found that:(a)There was a continuous trend of declining carbon emissions,increased carbon uptake,and decreased CBI in Aba prefecture during the sample period,but there is a large variability among county-level cities;(b)Aba prefecture differs in the spatiotemporal distribution of carbon emissions,carbon uptake,and CBI.Based on the research results,we propose several optimized paths for alleviating the current carbon pressure situation in the Northwestern Sichuan.
文摘Considering the growing prominence of global environmental issues,a low-carbon economy has emerged as a crucial direction for economic development across various countries.As the world’s second-largest economy,China has also witnessed the influence of a low-carbon economy on its international trade development.This article aims to commence with an exploration of the development background,meaning,and significance of a low-carbon economy.Subsequently,it delves into an in-depth analysis of the impact that a low-carbon economy has on China’s international trade.The article concludes by proposing pertinent countermeasures and suggestions.
文摘With the continuous implementation of national measures related to carbon neutrality strategy,the concept of a low-carbon economy has been deeply rooted in people’s hearts.Low-carbon tourism has gradually become an inevitable trend,and the tourism industry is also undergoing orderly transformation and upgrading.To promote the sustainable development of the tourism industry,the tourism and hotel industry should also shift towards a low-carbon and green model.Hotel activities can easily bring related environmental issues,such as energy consumption,garbage generation,ecological pollution,etc.Therefore,building a green hotel will bring huge social and economic benefits to the low-carbon tourism industry.This article will address the above issues and take a low-carbon economy as the starting point,proposing sustainable development strategies and suggestions for green hotels from both the internal and external environment of the hotel,creating a low-carbon management atmosphere,and promoting the low-carbon operation of the green hotel industry.
基金sponsored by the Energy Foundation (EF) and World Wildlife Fund (WWF).
文摘Global warming threatens the lives and development of human beings and has become one of the major challenges tohumanity in the 21st century.With China’s continuous economic strengthening and closer contact with the world economy,prospects of China’s energy demands,energy supply roadmap and related carbon emissions have become the focus ofvarious organizations.By applying a scenario analysis,this report analyzes and forecasts China’s energy demands andcarbon emissions trends over the coming thirty to fifty years.Results indicate that under certain conditions,it will bepossible for China to take on a low carbon development path with Chinese characteristics.However,China needs overalladjustments in policy,institutions,structure,technology as well as strong support from international economic andpolitical environments.
文摘A suitable carburized microstructure with fine granular dispersed carbides in hypereutectoidzone,ultra fine martensite in matrix and recrystallized austenite to be refined to the grain size of 12～14 hasbeen obtained by a new process,which is a high carbon concentration carburizing with rare earth element atlow temperature(860～880℃)in a discontinuous gas carburization furnace.There was not much differencefor the microstructure in eutectic zone between this and conventional process.Forming mechanism ofgranular carbides has been also studied in this paper.
基金financially supported by the National Natural Science Foundation of China (No.51404022)
文摘During the production of Ti-bearing Al-killed ultra-low-carbon(ULC) steel, two different heating processes were used when the converter tapping temperature or the molten steel temperature in the Ruhrstahl–Heraeus(RH) process was low: heating by Al addition during the RH decarburization process and final deoxidation at the end of the RH decarburization process(process-Ⅰ), and increasing the oxygen content at the end of RH decarburization, heating and final deoxidation by one-time Al addition(process-Ⅱ). Temperature increases of 10°C by different processes were studied; the results showed that the two heating processes could achieve the same heating effect. The T.[O] content in the slab and the refining process was better controlled by process-Ⅰ than by process-Ⅱ. Statistical analysis of inclusions showed that the numbers of inclusions in the slab obtained by process-Ⅰ were substantially less than those in the slab obtained by process-Ⅱ. For process-Ⅰ, the Al_2O_3 inclusions produced by Al added to induce heating were substantially removed at the end of decarburization. The amounts of inclusions were substantially greater for process-Ⅱ than for process-Ⅰ at different refining stages because of the higher dissolved oxygen concentration in process-Ⅱ. Industrial test results showed that process-Ⅰ was more beneficial for improving the cleanliness of molten steel.
基金Acknowledgements-Financial support of National Science and Technology Ministry to the research projectfundamental research of
文摘The microstructure evolution during deformation enhanced transformation of under cooled austenite of a plain low carbon steel has been investigated by means of hot compression simulation experiment under various conditions of strain rate,deforma- tion temperature and strain. The effect of austenite grain size on the strain enhanced ferrite transformation has been studied. The ferrite dynamic recrystallization involved in successive hot deformation has been explored.
文摘The influence of hot deformation conditions on continuous cooling bainitic transformation has been investigated for a low carbon microalloyed steel. The CCT diagrams show that deformation in unrecrpstallized austcnite ation can accelerate transformation process. Bainitic transformation in intermediate transformation temperature region is prominent, and the proeutectoid polygonal ferrite transformation at evelated high temperature is suppressed. According to optical and TEM analyses, low carbon bainitic ferrite is characterized by granular and lathlike ferrite, based on the cooling rate and deformation conditions. For nondeformation, groaps of coarse parallel ferrite lath form from the prior austenite grain boundaries with the same crystallographic orientation. For heavy deformaton, cell structure within the austenite grains due to the high dislocation density formed, which provides more nucleation sites for bainite ferrite. So deformation can discontinue the growth of ferrite laths and decrease the length of ferrite laths.
基金This study was supported by the project of China Geological Survey(DD20211413,Comprehensive Evaluation of Ecological Protection and Utilization of Natural Resources).
文摘Climate change is a common problem in human society.The Chinese government promises to peak carbon dioxide emissions by 2030 and strives to achieve carbon neutralization by 2060.The proposal of the goal of carbon peak and carbon neutralization has led China into the era of climate economy and set off a green change with both opportunities and challenges.On the basis of expounding the objectives and specific connotation of China’s carbon peak and carbon neutralization,this paper systematically discusses the main implementation path and the prospect of China’s carbon peak and carbon neutralization.China’s path to realizing carbon neutralization includes four directions:(1)in terms of carbon dioxide emission control:energy transformation path,energy conservation,and emission reduction path;(2)for increasing carbon sink:carbon capture,utilization,and storage path,ecological governance,and land greening path;(3)in key technology development:zero-carbon utilization,coal new energy coupling,carbon capture utilization and storage(CCUS),energy storage technology and other key technology paths required to achieve carbon peak and carbon neutralization;(4)from the angle of policy development:Formulate legal guarantees for the government to promote the carbon trading market;Formulate carbon emission standards for enterprises and increase publicity and education for individuals and society.Based on practicing the goal and path of carbon peak and carbon neutralization,China will vigorously develop low carbon and circular economy and promote green and high-quality economic development;speed up to enter the era of fossil resources and promoting energy transformation;accelerate the integrated innovation of green and low-carbon technologies and promote carbon neutrality.
文摘The characteristics of nanosized precipitates in steels depend on the heat-treatment parameters. The effects of characteristics of vanadium precipitates formed during isothermal heat treatment on the hardness of the ferrite matrix in low-carbon vanadium-alloyed steel were investigated through analysis of transmission electron microscopy images and microhardness measurements. The results show that, during isothermal holding in the temperature range from 675 to 750℃, only interphase precipitation occurs, whereas only random precipitation occurs in the ferrite matrix during holding at 600℃. Furthermore, during isothermal heat treatment between 600 and 675℃, both random and interphase precipitates occurred in the ferrite. Nanoscale vanadium carbides with different atomic ratios of vanadium(V) and carbon(C) were the dominant precipitates in the random and interphase precipitates. The sizes of random precipitation carbides were smaller than those of interphase ones. Also, the sample isothermally heat treated at 650℃ for 900s exhibited a higher hardness with a narrower hardness distribution.
