Based on the analysis of primary energy consumption structure in five main provinces or municipalities in China,the factors that affect carbon emissions in the five study areas are analyzed quantitatively and comparat...Based on the analysis of primary energy consumption structure in five main provinces or municipalities in China,the factors that affect carbon emissions in the five study areas are analyzed quantitatively and comparatively with the decomposition analysis method.Empirical results demonstrate that the decomposition models of carbon emissions can be defined as ＂municipality model＂ and ＂provincial model＂,and the population factor of ＂municipal model＂ plays a significant role in carbon emissions than that of ＂provincial model＂.Either positive or negative effects of energy structure can be found in five different areas.However,there is a general trend that energy structure effort is becoming more and more important.Based on the characteristics and trends of carbon emissions in different areas,the carbon reduction measures are proposed as well.展开更多
The determination of carbon emission from foundation pit engineering is a tough and complex project owing to its characteristics including large material consumption,short use time,difficult recycling and no operation...The determination of carbon emission from foundation pit engineering is a tough and complex project owing to its characteristics including large material consumption,short use time,difficult recycling and no operation stage.To overcome these limitations,the calculation boundary and calculation method for carbon emission of foundation pit project are defined in this paper,which is successfully applied in the carbon emission analysis of the actual engineering project,i.e.the construction of large-scale foundation pit of Kunming comprehensive transportation international hub.All the carbon emissions coresponding to four working stages including building materials production,building materials transportation,construction and demolition were calculated and anatomized.The results revealed that the content of CO_(2) released in the stage of building materials production accounts for 89.3%of the total carbon emission,which means the amount of building materials consumed in the engineering project is the crucial factor to control the carbon emission.Besides,two kinds of carbon reduction measures,i.e.optimization design of support scheme and recycling waste materials of internal support demolition,were explored by analyzing the proportion and average value of carbon emission from different sub project of the support structure.A pronounced effect of carbon reduction was achieved.Furthermore,both a fast calculation method of carbon emission factor of unit work volume and general carbon reduction measures are proposed in this paper,which could provide a reference and new viewpoint for the engineers and designers to calculate and analyze the carbon emission and to take effective carbon reduction measures.展开更多
Natural events such as floods and landslides can have severe consequences.The risks are expected to increase,both as a consequence of climate change and due to increased vulnerabilities,especially in urban areas.Altho...Natural events such as floods and landslides can have severe consequences.The risks are expected to increase,both as a consequence of climate change and due to increased vulnerabilities,especially in urban areas.Although preventive measures are often cost-effective,some measures are beneficial to certain values,while some may have negative impacts on other values.The aim of the study presented here was to investigate two frameworks used for assessing the effectiveness and sustainability of physical and nonphysical flood and landslide risk reduction measures.The study is based on literature,available information from authorities and municipalities,expert knowledge and experience,and stakeholder views and values.The results indicate that the risks for suboptimization or maladaptation are reduced if many aspects are included and a broad spectrum of stakeholders are involved.The sustamability assessment tools applied here can contribute to a more transparent and sustainable risk management process by assessing strategies and interventions with respect to both short- and long-term perspectives,including local impacts and wider environmental impacts caused by climate change,for example.The tools can also cover social and economic aspects.The assessment tools provide checklists that can support decision processes,thus allowing for more transparent decisions.展开更多
The flat-plate turbulent boundary layer at Reτ=1140 is manipulated using a spanwise array of bidirectional dielectric barrier discharge(DBD)plasma actuators.Based on the features of no moving mechanical parts in the ...The flat-plate turbulent boundary layer at Reτ=1140 is manipulated using a spanwise array of bidirectional dielectric barrier discharge(DBD)plasma actuators.Based on the features of no moving mechanical parts in the DBD plasma control technology and hot-wire anemometer velocity measurements,a novel convenient method of local drag reduction(DR)measurement is proposed by measuring the single-point velocity within the linear region of the viscous sublayer.We analyze the premise of using the method,and the maximum effective measurement range of-73.1%<DR<42.2%is obtained according to the experimental environment in this work.The local drag decreases downstream of the center of two adjacent upper electrodes and increases downstream of the upper electrodes.The magnitude of the local DR increases with increasing voltage and decreases as it moves away from the actuators.For the spanwise position in between,the streamwise distribution of the local DR is very dependent on the voltage.The variable-interval time-average detection results reveal that all bursting intensities are reduced compared to the baseline,and the amount of reduction is comparable to the absolute values of the local DR.Compared with previous results,we infer that the control mechanism is that many meandering streaks are combined together into single stabilized streaks.展开更多
Greenhouse gas emissions are increas- ing every year and their effect on the environment is becoming increasingly serious. In 2009, the concen- tration of carbon dioxide in the earth＇s atmosphere reached 387 μL/L, t...Greenhouse gas emissions are increas- ing every year and their effect on the environment is becoming increasingly serious. In 2009, the concen- tration of carbon dioxide in the earth＇s atmosphere reached 387 μL/L, the highest level in recorded histo- ry. This paper summarizes the global carbon emission situation, sources of greenhouse gases, and the con-tribution of agriculture to the accumutauon ot green- house gases. Several scientific measures are proposed to reduce greenhouse gas emissions resulting from ru- minant production such as improving animal perform- ance, regulating the rumen environment, and reduc- ing the amount of greenhouse gases emitted from live- stock manure.展开更多
The filter capacitor stack is one of the main acoustic noise sources in high-voltage DC(HVDC) converter stations.As HVDC systems are built more and more recently,it is significant to research the audible noise of filt...The filter capacitor stack is one of the main acoustic noise sources in high-voltage DC(HVDC) converter stations.As HVDC systems are built more and more recently,it is significant to research the audible noise of filter capacitors.In this paper,the current situation of research on vibration and audible noise of filter capacitors in HVDC converter stations,which is departed into three parts—generation mechanism,prediction methods,and reduction measures,is presented and the research achievements are discussed.Scholars have built the model that the alternating electric force caused by the voltage conduces to the vibration,which propagates to the enclosure and radiates audible noise.As a result,the parts contributing most to the generation of audible noise are the top and the bottom of capacitors. In the noise level prediction respect,several methods have been prospected including impact hammer,sweep frequency, impact current,monopole and Kirchhoff formula method,which are suitable for single capacitors or capacitors stacks individually.However,the sweep frequency method is restricted by experiment condition,and the impact current method needs further research and verified.On the other hand,CIGRE WG14.26 provides three sound reduction measures,but all of them are not so practicable,while MPP absorber and compressible space absorber prospected by Dr.Wu Peng are proved to be effective.The sound barriers are also considered by scholars,and the acoustic directivity performance of capacitors is also researched.Besides,the developing direction of each research field is prospected in corresponding part.展开更多
Strict air pollution control measures were conducted during the Youth Olympic Games(YOG)period at Nanjing city and surrounding areas in August 2014.This event provides a unique chance to evaluate the effect of governm...Strict air pollution control measures were conducted during the Youth Olympic Games(YOG)period at Nanjing city and surrounding areas in August 2014.This event provides a unique chance to evaluate the effect of government control measures on regional atmospheric pollution and greenhouse gas emissions.Many previous studies have observed significant reductions of atmospheric pollution species and improvement in air quality,while no study has quantified its synergism on anthropogenic CO_(2)emissions,which can be coreduced with air pollutants.To better understand to what extent these pollution control measures have reduced anthropogenic CO_(2)emissions,we conducted atmospheric CO_(2)measurements at the suburban site in Nanjing city from 1^(st) July to 30^(th) September 2014 and 1^(st) August to 31^(st) August 2015,obvious decrease in atmospheric CO_(2)was observed between YOG and the rest period.By coupling the a prioriemission inventory with atmospheric transport model,we applied the scale factor Bayesian inversion approach to derive the posteriori CO_(2)emissions in YOG period and regular period.Results indicate CO_(2)emissions from power industry decreased by 45%,and other categories also decreased by 16%for manufacturing combusting,and 37%for non-metallic mineral production.Monthly total anthropogenic CO_(2)emissions were 9.8(±3.6)×10^(9) kg/month CO_(2) for regular period and decreased to 6.2(±1.9)×10^(9) kg/month during the YOG period in Nanjing city,with a 36.7%reduction.When scaling up to whole Jiangsu Province,anthropogenic CO_(2)emissions were 7.1(±2.4)×10^(10) kg/month CO_(2)for regular period and decreased to 4.4(±1.2)×10^(10)kg/month CO_(2) during the YOG period,yielding a 38.0%reduction.展开更多
For achieving air pollutant emission reduction targets,total pollutant amount control is being continuously promoted in China.However,the traditional pattern of pollutant emission reduction allocation regardless of ec...For achieving air pollutant emission reduction targets,total pollutant amount control is being continuously promoted in China.However,the traditional pattern of pollutant emission reduction allocation regardless of economic cost often results in unreasonable emission reduction pathways,and industrial enterprises as the main implementers have to pay excessively high costs.Therefore,this study adopted economic efficiency as its main consideration,used specific emission reduction measures(ERMs)of industrial enterprises as minimum allocation units,and constructed an enterprise-level pollutant emission reduction allocation(EPERA)model with minimization of the total abatement cost(TAC)as the objective function,and fairness and feasibility as constraints for emission reduction allocation.Taking City M in China as an example,the EPERA model was used to construct a Pareto optimal frontier and obtain the optimal trade-off result.Results showed that under basic and strict emission reduction regulations,the TAC of the optimal trade-off point was reduced by 46.40%and 45.77%,respectively,in comparison with that achieved when only considering fairness,and the Gini coefficient was 0.26 and 0.31,respectively.The abatement target was attained with controllable cost and relatively fair and reasonable allocation.In addition,enterprises allocated different emission reduction quotas under different ERMs had specific characteristics that required targeted optimization of technology and equipment to enable them to achieve optimal emission reduction effects for the same abatement cost.展开更多
A measuring method of the echo reduction of passive materials by using the time reversal（TR） technique is presented. To measure the echo reduction of a sample with this approach, the received signals are firstly foc...A measuring method of the echo reduction of passive materials by using the time reversal（TR） technique is presented. To measure the echo reduction of a sample with this approach, the received signals are firstly focused according to the TR theory. Then, the sample is removed and the TR processing is again employed to realize the focus of the received signal.Finally, the echo reduction of the sample is evaluated with these focusing signals. Besides, to calibrate the measured echo reduction via the TR technique, a standard sample is employed to measure a constant coefficient that only depends on the measurement environment. An aluminum plate sample and a steel plate sample with the same size of 1.1 mxl.O m x0.005 m axe tested in a wave guide tank. The experimental results show that the calibrated values are well consistent with theoretical results under the free field at the measured frequency range of0.5-20 kHz. The relative errors of all the measured values are less than 10% and the values of the expanded uncertainty are less than 1.5 dB. The TR processing focuses the energy in spatial domain and temporal domain, so it can be used to measure the echo reduction of passive materials in the environments with reflections induced by boundaries and low frequency sources.展开更多
The measurement of an extremely small magneto-optical polarization rotation angle with high sensitivity is integral to many scientific and technological applications. In this Letter, we have presented a technique base...The measurement of an extremely small magneto-optical polarization rotation angle with high sensitivity is integral to many scientific and technological applications. In this Letter, we have presented a technique based on Faraday modulation combined with the optical differential method to measure an extremely small polari- zation rotation angle with high sensitivity. The theoretical and experimental results show that common mode noise is reduced appreciably and signal to noise ratio is enhanced. The effectiveness of this technique has been demonstrated by measuring the Verdet constant of terbium gallium garnet glass and measuring the small polari- zation rotation angle. A sensitivity of enhancement of one order of magnitude has been achieved using differ- ential detection based on Faraday modulation.展开更多
基金Project supported by the Twelfth Five-Year-Plan on Energy Conservation in Shanghai Colleges and Universitiesthe Shanghai Low-Carbon City Development Project
文摘Based on the analysis of primary energy consumption structure in five main provinces or municipalities in China,the factors that affect carbon emissions in the five study areas are analyzed quantitatively and comparatively with the decomposition analysis method.Empirical results demonstrate that the decomposition models of carbon emissions can be defined as ＂municipality model＂ and ＂provincial model＂,and the population factor of ＂municipal model＂ plays a significant role in carbon emissions than that of ＂provincial model＂.Either positive or negative effects of energy structure can be found in five different areas.However,there is a general trend that energy structure effort is becoming more and more important.Based on the characteristics and trends of carbon emissions in different areas,the carbon reduction measures are proposed as well.
基金supported by Science and Technology Program of the Ministry of Housing and Urban-Rural Development[2022-S-031]CSCEC1B Technical and Development Plan[Grant No.CSCEC1B-2021-33].
文摘The determination of carbon emission from foundation pit engineering is a tough and complex project owing to its characteristics including large material consumption,short use time,difficult recycling and no operation stage.To overcome these limitations,the calculation boundary and calculation method for carbon emission of foundation pit project are defined in this paper,which is successfully applied in the carbon emission analysis of the actual engineering project,i.e.the construction of large-scale foundation pit of Kunming comprehensive transportation international hub.All the carbon emissions coresponding to four working stages including building materials production,building materials transportation,construction and demolition were calculated and anatomized.The results revealed that the content of CO_(2) released in the stage of building materials production accounts for 89.3%of the total carbon emission,which means the amount of building materials consumed in the engineering project is the crucial factor to control the carbon emission.Besides,two kinds of carbon reduction measures,i.e.optimization design of support scheme and recycling waste materials of internal support demolition,were explored by analyzing the proportion and average value of carbon emission from different sub project of the support structure.A pronounced effect of carbon reduction was achieved.Furthermore,both a fast calculation method of carbon emission factor of unit work volume and general carbon reduction measures are proposed in this paper,which could provide a reference and new viewpoint for the engineers and designers to calculate and analyze the carbon emission and to take effective carbon reduction measures.
基金supported by the Swedish Civil Contingencies Agency(MSB)the Swedish Government through the Centre for Natural Disaster Science(CNDS)the Faculty of Health,Science and Technology at Karlstad University
文摘Natural events such as floods and landslides can have severe consequences.The risks are expected to increase,both as a consequence of climate change and due to increased vulnerabilities,especially in urban areas.Although preventive measures are often cost-effective,some measures are beneficial to certain values,while some may have negative impacts on other values.The aim of the study presented here was to investigate two frameworks used for assessing the effectiveness and sustainability of physical and nonphysical flood and landslide risk reduction measures.The study is based on literature,available information from authorities and municipalities,expert knowledge and experience,and stakeholder views and values.The results indicate that the risks for suboptimization or maladaptation are reduced if many aspects are included and a broad spectrum of stakeholders are involved.The sustamability assessment tools applied here can contribute to a more transparent and sustainable risk management process by assessing strategies and interventions with respect to both short- and long-term perspectives,including local impacts and wider environmental impacts caused by climate change,for example.The tools can also cover social and economic aspects.The assessment tools provide checklists that can support decision processes,thus allowing for more transparent decisions.
基金the financial support received from the National Science Fund for Distinguished Young Scholars(No.12102359)。
文摘The flat-plate turbulent boundary layer at Reτ=1140 is manipulated using a spanwise array of bidirectional dielectric barrier discharge(DBD)plasma actuators.Based on the features of no moving mechanical parts in the DBD plasma control technology and hot-wire anemometer velocity measurements,a novel convenient method of local drag reduction(DR)measurement is proposed by measuring the single-point velocity within the linear region of the viscous sublayer.We analyze the premise of using the method,and the maximum effective measurement range of-73.1%<DR<42.2%is obtained according to the experimental environment in this work.The local drag decreases downstream of the center of two adjacent upper electrodes and increases downstream of the upper electrodes.The magnitude of the local DR increases with increasing voltage and decreases as it moves away from the actuators.For the spanwise position in between,the streamwise distribution of the local DR is very dependent on the voltage.The variable-interval time-average detection results reveal that all bursting intensities are reduced compared to the baseline,and the amount of reduction is comparable to the absolute values of the local DR.Compared with previous results,we infer that the control mechanism is that many meandering streaks are combined together into single stabilized streaks.
文摘Greenhouse gas emissions are increas- ing every year and their effect on the environment is becoming increasingly serious. In 2009, the concen- tration of carbon dioxide in the earth＇s atmosphere reached 387 μL/L, the highest level in recorded histo- ry. This paper summarizes the global carbon emission situation, sources of greenhouse gases, and the con-tribution of agriculture to the accumutauon ot green- house gases. Several scientific measures are proposed to reduce greenhouse gas emissions resulting from ru- minant production such as improving animal perform- ance, regulating the rumen environment, and reduc- ing the amount of greenhouse gases emitted from live- stock manure.
基金Supported by National Natural Science Foundation of China(50907046)
文摘The filter capacitor stack is one of the main acoustic noise sources in high-voltage DC(HVDC) converter stations.As HVDC systems are built more and more recently,it is significant to research the audible noise of filter capacitors.In this paper,the current situation of research on vibration and audible noise of filter capacitors in HVDC converter stations,which is departed into three parts—generation mechanism,prediction methods,and reduction measures,is presented and the research achievements are discussed.Scholars have built the model that the alternating electric force caused by the voltage conduces to the vibration,which propagates to the enclosure and radiates audible noise.As a result,the parts contributing most to the generation of audible noise are the top and the bottom of capacitors. In the noise level prediction respect,several methods have been prospected including impact hammer,sweep frequency, impact current,monopole and Kirchhoff formula method,which are suitable for single capacitors or capacitors stacks individually.However,the sweep frequency method is restricted by experiment condition,and the impact current method needs further research and verified.On the other hand,CIGRE WG14.26 provides three sound reduction measures,but all of them are not so practicable,while MPP absorber and compressible space absorber prospected by Dr.Wu Peng are proved to be effective.The sound barriers are also considered by scholars,and the acoustic directivity performance of capacitors is also researched.Besides,the developing direction of each research field is prospected in corresponding part.
基金supported by the Natural Science Foundation of Jiangsu Province (No.BK20200802 to Cheng Hu)the National Key R&D Program of China (No.2020YFA0607501&2019YFA0607202 to WX)+4 种基金The National Natural Science Foundation of China (No.42021004)support by Technology Foundation for Selected Overseas Chinese Scholar,Nanjing (no.013108039)the Open Research Project of Shangdianzi National Atmospheric Background Station (SDZ2020617)start-up foundation from Nanjing Forestry Universitysupport from the Jiangxi Provincial Natural Science Foundation (No.20202BAB213019).
文摘Strict air pollution control measures were conducted during the Youth Olympic Games(YOG)period at Nanjing city and surrounding areas in August 2014.This event provides a unique chance to evaluate the effect of government control measures on regional atmospheric pollution and greenhouse gas emissions.Many previous studies have observed significant reductions of atmospheric pollution species and improvement in air quality,while no study has quantified its synergism on anthropogenic CO_(2)emissions,which can be coreduced with air pollutants.To better understand to what extent these pollution control measures have reduced anthropogenic CO_(2)emissions,we conducted atmospheric CO_(2)measurements at the suburban site in Nanjing city from 1^(st) July to 30^(th) September 2014 and 1^(st) August to 31^(st) August 2015,obvious decrease in atmospheric CO_(2)was observed between YOG and the rest period.By coupling the a prioriemission inventory with atmospheric transport model,we applied the scale factor Bayesian inversion approach to derive the posteriori CO_(2)emissions in YOG period and regular period.Results indicate CO_(2)emissions from power industry decreased by 45%,and other categories also decreased by 16%for manufacturing combusting,and 37%for non-metallic mineral production.Monthly total anthropogenic CO_(2)emissions were 9.8(±3.6)×10^(9) kg/month CO_(2) for regular period and decreased to 6.2(±1.9)×10^(9) kg/month during the YOG period in Nanjing city,with a 36.7%reduction.When scaling up to whole Jiangsu Province,anthropogenic CO_(2)emissions were 7.1(±2.4)×10^(10) kg/month CO_(2)for regular period and decreased to 4.4(±1.2)×10^(10)kg/month CO_(2) during the YOG period,yielding a 38.0%reduction.
基金This study was supported by the Capital Blue Sky Action Cultivation Program of“Research on the Whole Process Control Technology of Pollution Sources in Industrial Parks and Research and Demonstration of Smart Environmental Protection Platforms”Project of Beijing Science and Technology Plan(Project No.Z191100009119010).
文摘For achieving air pollutant emission reduction targets,total pollutant amount control is being continuously promoted in China.However,the traditional pattern of pollutant emission reduction allocation regardless of economic cost often results in unreasonable emission reduction pathways,and industrial enterprises as the main implementers have to pay excessively high costs.Therefore,this study adopted economic efficiency as its main consideration,used specific emission reduction measures(ERMs)of industrial enterprises as minimum allocation units,and constructed an enterprise-level pollutant emission reduction allocation(EPERA)model with minimization of the total abatement cost(TAC)as the objective function,and fairness and feasibility as constraints for emission reduction allocation.Taking City M in China as an example,the EPERA model was used to construct a Pareto optimal frontier and obtain the optimal trade-off result.Results showed that under basic and strict emission reduction regulations,the TAC of the optimal trade-off point was reduced by 46.40%and 45.77%,respectively,in comparison with that achieved when only considering fairness,and the Gini coefficient was 0.26 and 0.31,respectively.The abatement target was attained with controllable cost and relatively fair and reasonable allocation.In addition,enterprises allocated different emission reduction quotas under different ERMs had specific characteristics that required targeted optimization of technology and equipment to enable them to achieve optimal emission reduction effects for the same abatement cost.
文摘A measuring method of the echo reduction of passive materials by using the time reversal（TR） technique is presented. To measure the echo reduction of a sample with this approach, the received signals are firstly focused according to the TR theory. Then, the sample is removed and the TR processing is again employed to realize the focus of the received signal.Finally, the echo reduction of the sample is evaluated with these focusing signals. Besides, to calibrate the measured echo reduction via the TR technique, a standard sample is employed to measure a constant coefficient that only depends on the measurement environment. An aluminum plate sample and a steel plate sample with the same size of 1.1 mxl.O m x0.005 m axe tested in a wave guide tank. The experimental results show that the calibrated values are well consistent with theoretical results under the free field at the measured frequency range of0.5-20 kHz. The relative errors of all the measured values are less than 10% and the values of the expanded uncertainty are less than 1.5 dB. The TR processing focuses the energy in spatial domain and temporal domain, so it can be used to measure the echo reduction of passive materials in the environments with reflections induced by boundaries and low frequency sources.
基金supported by the National Key R&D Program of China(No.2017YFB0503100)the National Science Foundation of China(NSFC)(No.61227902)
文摘The measurement of an extremely small magneto-optical polarization rotation angle with high sensitivity is integral to many scientific and technological applications. In this Letter, we have presented a technique based on Faraday modulation combined with the optical differential method to measure an extremely small polari- zation rotation angle with high sensitivity. The theoretical and experimental results show that common mode noise is reduced appreciably and signal to noise ratio is enhanced. The effectiveness of this technique has been demonstrated by measuring the Verdet constant of terbium gallium garnet glass and measuring the small polari- zation rotation angle. A sensitivity of enhancement of one order of magnitude has been achieved using differ- ential detection based on Faraday modulation.
