As a common transportation facility, speed humps can control the speed of vehicles on special road sections to reduce traffic risks. At the same time, they also cause instantaneous traffic emissions. Based on the clas...As a common transportation facility, speed humps can control the speed of vehicles on special road sections to reduce traffic risks. At the same time, they also cause instantaneous traffic emissions. Based on the classic instantaneous traffic emission model and the limited deceleration capacity microscopic traffic flow model with slow-to-start rules, this paper has investigated the impact of speed humps on traffic flow and the instantaneous emissions of vehicle pollutants in a single lane situation. The numerical simulation results have shown that speed humps have significant effects on traffic flow and traffic emissions. In a free-flow region, the increase of speed humps leads to the continuous rise of CO_(2), NO_(X) and PM emissions. Within some density ranges, one finds that these pollutant emissions can evolve into some higher values under some random seeds. Under other random seeds, they can evolve into some lower values. In a wide moving jam region, the emission values of these pollutants sometimes appear as continuous or intermittent phenomenon. Compared to the refined Na Sch model, the present model has lower instantaneous emissions such as CO_(2), NO_(X) and PM and higher volatile organic components(VOC) emissions. Compared to the limited deceleration capacity model without slow-to-start rules, the present model also has lower instantaneous emissions such as CO_(2), NO_(X) and PM and higher VOC emissions in a wide moving jam region. These results can also be confirmed or explained by the statistical values of vehicle velocity and acceleration.展开更多
This paper investigates the impacts of a bus holding strategy on the mutual interference between buses and passenger cars in a non-dedicated bus route,as well as the impacts on the characteristics of pollutant emissio...This paper investigates the impacts of a bus holding strategy on the mutual interference between buses and passenger cars in a non-dedicated bus route,as well as the impacts on the characteristics of pollutant emissions of passenger cars.The dynamic behaviors of these two types of vehicles are described using cellular automata(CA)models under open boundary conditions.Numerical simulations are carried out to obtain the phase diagrams of the bus system and the trajectories of buses and passenger cars before and after the implementation of the bus holding strategy under different probabilities of passenger cars entering a two-lane mixed traffic system.Then,we analyze the flow rate,satisfaction rate,and pollutant emission rates of passenger cars together with the performance of a mixed traffic system.The results show that the bus holding strategy can effectively alleviate bus bunching,whereas it has no significant impact on the flow rate and pollutant emission rates of passenger cars;the flow rate,satisfaction rate,and pollutant emission rates of passenger cars for either the traffic system or for each lane are influenced by the bus departure interval and the number of passengers arriving at bus stops.展开更多
This study aims to analysis the influence of economic growth(EG)and energy consumption(EC)on sulfur dioxide emissions(SE)in China.Accordingly,this study explores the link between EG,EC,and SE for 30 provinces in China...This study aims to analysis the influence of economic growth(EG)and energy consumption(EC)on sulfur dioxide emissions(SE)in China.Accordingly,this study explores the link between EG,EC,and SE for 30 provinces in China over the span of 2000-2019.This study also analyzes cross-sectional dependence tests,panel unit root tests,Westerlund panel cointegration tests,Dumitrescu-Hurlin(D-H)causality tests.According to the test results,there is an inverted U-shaped association between EG and SE,and the assumption of the Environmental Kuznets Curve(EKC)is verified.The signs of EG and EC in the fixed effect(FE)and random effect(RE)methods are in line with those in the dynamic ordinary least squares(DOLS),fully modified ordinary least squares(FMOLS)and autoregressive distributed lag(ARDL)estimators.Moreover,the results verified that EC can obviously positive impact the SE.To reduce SE in China,government and policymakers can improve air quality by developing cleaner energy sources and improving energy efficiency.This requires the comprehensive use of policies,regulations,economic incentives,and public participation to promote sustainable development.展开更多
Investing in projects that support environmental benefits,such as tree harvesting,has the potential to reduce air pollution levels in the atmosphere in the future.However,this kind of investment may increase the curre...Investing in projects that support environmental benefits,such as tree harvesting,has the potential to reduce air pollution levels in the atmosphere in the future.However,this kind of investment may increase the current level of emissions.Therefore,it is necessary to estimate how much the policy affects the current level of CO_(2) emissions.This makes sure the policy doesn’t increase the level of CO_(2) emis-sions.This study aims to analyze the effect of the One Bil-lion Trees program on CO_(2) emissions in New Zealand by employing the 2020 input–output table analysis.This inves-tigation examines the direct and indirect effects of policy on both the demand and supply sides across six regions of New Zealand.The results of this study for the first year of plantation suggest that the policy increases the level of CO_(2) emissions in all regions,especially in the Waikato region.The direct and indirect impact of the policy leads to 64 kt of CO_(2) emissions on the demand side and 270 kt of CO_(2) emis-sions on the supply side.These lead to 0.19 and 0.74%of total CO_(2) emissions being attributed to investment shocks.Continuing the policy is recommended,as it has a low effect on CO_(2) emissions.However,it is crucial to prioritize the use of low-carbon machinery that uses fossil fuels during the plantation process.展开更多
Accurate thrust assessment is crucial for characterizing the performance of micro-thrusters.This paper presents a comprehensive evaluation of the thrust generated by a needle-type indium field emission electric propul...Accurate thrust assessment is crucial for characterizing the performance of micro-thrusters.This paper presents a comprehensive evaluation of the thrust generated by a needle-type indium field emission electric propulsion(In-FEEP)micro-thruster using three methods based on a pendulum:direct thrust measurement,indirect plume momentum transfer and beam current diagnostics.The experimental setup utilized capacitive displacement sensors for force detection and a voice coil motor as a feedback actuator,achieving a resolution better than 0.1μN.Key performance factors such as ionization and plume divergence of ejected charged particles were also examined.The study reveals that the high applied voltage induces significant electrostatic interference,becoming the dominant source of error in direct thrust measurements.Beam current diagnostics and indirect plume momentum measurements were conducted simultaneously,showing strong agreement within a deviation of less than 0.2N across the operational thrust range.The results from all three methods are consistent within the error margins,verifying the reliability of the indirect measurement approach and the theoretical thrust model based on the electrical parameters of In-FEEP.展开更多
Radiative cooling fabric creates a thermally comfortable environment without energy input,providing a sustainable approach to personal thermal management.However,most currently reported fabrics mainly focus on outdoor...Radiative cooling fabric creates a thermally comfortable environment without energy input,providing a sustainable approach to personal thermal management.However,most currently reported fabrics mainly focus on outdoor cooling,ignoring to achieve simultaneous cooling both indoors and outdoors,thereby weakening the overall cooling performance.Herein,a full-scale structure fabric with selective emission properties is constructed for simultaneous indoor and outdoor cooling.The fabric achieves 94%reflectance performance in the sunlight band(0.3–2.5μm)and 6%in the mid-infrared band(2.5–25μm),effectively minimizing heat absorption and radiation release obstruction.It also demonstrates 81%radiative emission performance in the atmospheric window band(8–13μm)and 25%radiative transmission performance in the mid-infrared band(2.5–25μm),providing 60 and 26 W m−2 net cooling power outdoors and indoors.In practical applications,the fabric achieves excellent indoor and outdoor human cooling,with temperatures 1.4–5.5℃ lower than typical polydimethylsiloxane film.This work proposes a novel design for the advanced radiative cooling fabric,offering significant potential to realize sustainable personal thermal management.展开更多
How to achieve the objective of reducing CO2 emissions has been an academic focus in China recently. The factors influencing CO2 emissions are the vital issue to accomplish the arduous target. Firstly, three influenti...How to achieve the objective of reducing CO2 emissions has been an academic focus in China recently. The factors influencing CO2 emissions are the vital issue to accomplish the arduous target. Firstly, three influential factors, the energy consumption, the proportion of tertiary industry in gross domestic product （GDP）, and the degree of dependence on foreign trade, are carefully selected, since all of them have closer grey relation with China＇s COz emissions compared with others when the grey relational analysis （GRA） method is applied. The study highlights co-integration relation of these four variables using the co-integration analysis method. And then a long-term co-integration equation and a short-term error correction model of China＇s CO2 emissions are devel- oped. Finally, the comparison is exerted between the forecast value and the actual value of China＇s CO2 emissions based on error correction model. The results and the relevant statistics tests show that the pro- posed model has better explanation capability and credibility.展开更多
Peatlands are one of the major natural sources of methane （CH4）, but the level of CH4 efflux is uncertain, especially in alpine peatlands. In this study, CH4 emission fluxes from natural and drained peatlands on the...Peatlands are one of the major natural sources of methane （CH4）, but the level of CH4 efflux is uncertain, especially in alpine peatlands. In this study, CH4 emission fluxes from natural and drained peatlands on the Qinghai- Tibet Plateau, southwest China, were measured from June to October in 2013 using the opaque static chamber technique and the Fast Greenhouse Gas Analyzer （DLT-100, Los Gatos Research Corp.）. CH4 emission fluxes ranged from 2.07 to 56.33 mg m^-2 h^-1 in natural peatlands and from 0.02 to 0.42 mg m^-2 h^-1 in drained peatlands. Mean CH4 emission flux was 19.13 mg m^-2 h^-1 in natural peatlands and 0.14 mg m^-2 h^-1 in drained peatlands. These results showed that drainage led to a significant decrease in CH4 emissions. CH4 emission fluxes for all sampling plots were significantly correlated with variation in water table depth for linear （R^2 = 0.453, P 〈 0.01） and exponential functions （R^2 = 0.429, P 〈 0.01）.展开更多
The prediction of gas emissions arising from underground coal mining has been the subject of extensive research for several decades, however calculation techniques remain empirically based and are hence limited to the...The prediction of gas emissions arising from underground coal mining has been the subject of extensive research for several decades, however calculation techniques remain empirically based and are hence limited to the origin of calculation in both application and resolution. Quantification and management of risk associated with sudden gas release during mining(outbursts) and accumulation of noxious or combustible gases within the mining environment is reliant on such predictions, and unexplained variation correctly requires conservative management practices in response to risk. Over 2500 gas core samples from two southern Sydney basin mines producing metallurgical coal from the Bulli seam have been analysed in various geospatial context including relationships to hydrological features and geological structures. The results suggest variability and limitations associated with the present traditional approaches to gas emission prediction and design of gas management practices may be addressed using predictions derived from improved spatial datasets, and analysis techniques incorporating fundamental physical and energy related principles.展开更多
Climate change and carbon emissions are major problems which are attracting worldwide attention. China has had its pilot carbon emission trading markets in seven regions for more than 3 years. What affects carbon emis...Climate change and carbon emissions are major problems which are attracting worldwide attention. China has had its pilot carbon emission trading markets in seven regions for more than 3 years. What affects carbon emission trading market in China is a big question. More attention is paid to how China promotes the carbon emission trading schemes in the whole country. This paper addresses concerns about the functioning of carbon emission trading schemes in seven pilot regions and takes the weekly data from November 25, 2013, to March 19, 2017. We employ a vector autoregressive model to study how coal price, oil price and stock index have affected the carbon price in China. The results indicate that carbon price is mainly affected by its own historical price; coal price and stock index have negative effects on carbon price, while oil price has a negative effect on carbon price during the first 3 weeks and then has a positive effect on carbon price. More regulatory attention and economic measures are needed to improve market efficiency, and the mechanisms of carbon emission trading schemes should be improved.展开更多
The fuel sulfur content in marine fuels has been regulated in Sulfur Emission Control Areas(SECAs) since January 2015. However, other fuel characteristics are also believed to have an impact on particle emissions, par...The fuel sulfur content in marine fuels has been regulated in Sulfur Emission Control Areas(SECAs) since January 2015. However, other fuel characteristics are also believed to have an impact on particle emissions, particularly on the number of particles emitted. This study investigates the impact of the content of aromatics in fuel. To achieve fuel blends with concentrations of aromatics similar to those found in marine fuel oils, i.e. 20%–30% by volume(%vol.), normal diesel oil(4%–5% vol. aromatics) is doped with a mixture of aromatics. Emission measurements are conducted in test-bed engine facilities and particle emissions over a wide size range are analyzed. Results show a decreased number of particles emitted(or not change) with an increase in the aromatic concentration in fuel. This is because there is a reduction in the cetane number of the fuel with an increased aromatic content, which effects the combustion process and results in decreased particle formation. However, when ignition improver is used to increase the cetane number, particle emissions remain at a lower level than for normal diesel oil; thereby emphasizing the presence of other factors in the formation of particles.展开更多
Hurricanes cause abrupt carbon reduction in forests, but silviculture treatment can be an effective means of quickly regenerating and restoring hurricane-damaged sites. This study assessed how silviculture treatments ...Hurricanes cause abrupt carbon reduction in forests, but silviculture treatment can be an effective means of quickly regenerating and restoring hurricane-damaged sites. This study assessed how silviculture treatments affect carbon balance after hurricane damage in central Hokkaido, Japan. We examined carbon storage in trees and underground vegetation as well as carbon emissions from silviculture operations in 25-year-old stands, where scarification and plantation occurred just after hurricane damage. The amount of carbon stored varied according to silviculture treatment. Among three scarification treatments, a scarified depth of 0 cm （understory vegetation removal） led to the largest amount of carbon stored （64.7 t·ha^-1 C）. Among four plantation treatments, the largest amount of carbon was stored in a Larix hybrid （L. gmelinii var. japonica × L. kaempferi） plantation （80.3 t·ha^-1 C）. The plantation of Abies sachalinensis was not successful at accumulating carbon （40.5·ha^-1 C）. The amount of carbon emitted from silviculture operations was 0.05-0.14 t·ha^-1 C, and it marginally affected the net carbon balance of the silviculture project. Results indicate that silviculture treatments should beperformed in an appropriate way to effectively recover the ability of carbon sequestration in hurricane-damaged forests.展开更多
The green and red up-conversion emissions centred at about 534, 549 and 663 nm of wavelength, corresponding respectively to the ^2H11/2 → ^4I15/2, ^4S3/2 → ^4I15/2 and ^4F9/2 → ^4I15/2 transitions of Er^3＋ ions, h...The green and red up-conversion emissions centred at about 534, 549 and 663 nm of wavelength, corresponding respectively to the ^2H11/2 → ^4I15/2, ^4S3/2 → ^4I15/2 and ^4F9/2 → ^4I15/2 transitions of Er^3＋ ions, have been observed for the Er^3＋-doped silicate glass excited by a 978 nm semiconductor laser beam. Excitation power dependent behaviour of the up-conversion emission intensity indicates that a two-photon absorption up-conversion process is responsible for the green and red up-conversion emissions. The temperature dependence of the green up-conversion emissions is also studied in a temperature range of 296-673 K, which shows that Er^3＋-doped silicate glass can be used as a sensor in high-temperature measurement.展开更多
The progress of economic globalization,the rapid growth of international trade,and the maritime transportation has played an increasingly significant role in the international supply chain.As a result,worldwide seapor...The progress of economic globalization,the rapid growth of international trade,and the maritime transportation has played an increasingly significant role in the international supply chain.As a result,worldwide seaports have suffered from a central problem,which appears in the form of massive amounts of fuel consumed and exhaust gas fumes emitted from the ships while berthed.Many ports have taken the necessary precautions to overcome this problem,while others still suffer due to the presence of technical and financial constraints.In this paper,the barriers,interconnection standards,rules,regulations,power sources,and economic and environmental analysis related to ships,shore-side power were studied in efforts to find a solution to overcome his problem.As a case study,this paper investigates the practicability,costs and benefits of switching from onboard ship auxiliary engines to shore-side power connection for high-speed crafts called Alkahera while berthed at the port of Safaga,Egypt.The results provide the national electricity grid concept as the best economical selection with 49.03 percent of annual cost saving.Moreover,environmentally,it could achieve an annual reduction in exhaust gas emissions of CO2,CO,NOx,P.M,and SO2by 276,2.32,18.87,0.825 and 3.84 tons,respectively.展开更多
For studying new and renewable energy as a substitute for fossil energy in primary energy consumption and its impact on carbon emissions to cope with economic uncertainties, a multi-sector DSGE model was employed to s...For studying new and renewable energy as a substitute for fossil energy in primary energy consumption and its impact on carbon emissions to cope with economic uncertainties, a multi-sector DSGE model was employed to simulate the dynamic impact on carbon emissions and macroeconomic development. The structural adjustment of energy consumption and the carbon emissions mitigation policy were considered in the model. The simulation results showed that using new and renewable energy instead of fossil energy is an optimal choice for the firms to comply with the regulations of carbon emission mitigation policy. Structural adjustment of energy consumption is the best route to achieve the dual goal of economic development and carbon emission reduction. Unexpected sharp fall in free carbon quota has a negative impact on the economy.展开更多
Graphene films are deposited on copper （Cu） and aluminum （Al） substrates, respectively, by using a microwave plasma chemical vapour deposition technique. Furthermore, these graphene films are characterized by a fi...Graphene films are deposited on copper （Cu） and aluminum （Al） substrates, respectively, by using a microwave plasma chemical vapour deposition technique. Furthermore, these graphene films are characterized by a field emission type scanning electron microscope （FE-SEM）, Raman spectra, and field emission （FE） I-V measurements. It is found that the surface morphologies of the films deposited on Cu and Al substrates are different： the field emission property of graphene film deposited on the Cu substrate is better than that on the Al substrate, and the lowest turn-on field of 2.4 V/p-m is obtained for graphene film deposited on the Cu substrate. The macroscopic areas of the graphene samples are all above 400 mm2.展开更多
Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for a ferry during operation.The emission factor for nitrogen...Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for a ferry during operation.The emission factor for nitrogen oxides is lower than what is typically found for marine gasoil but does not reach the tier III limit.The emissions of particulate matter are significantly lower than for fuel oils and similar to what is found for LNG engines.The main part of the particles can be found in the ultrafine range with the peak being at around 18 nm.About 93%of the particles are evaporated and absorbed when using a thermodenuder,and thus a large majority of the particles are volatile.Methanol is a potential future marine fuel that will reduce emissions of air pollutants and can be made as a biofuel to meet emission targets for greenhouse gases.展开更多
The regulated pollutants （CO,HC and NOx） and unregulated pollutants （volatile organic compounds and carbonyl compounds）,emitted from a dual fuel vehicle fueled with gasoline and E10 fuel,are measured under a trans...The regulated pollutants （CO,HC and NOx） and unregulated pollutants （volatile organic compounds and carbonyl compounds）,emitted from a dual fuel vehicle fueled with gasoline and E10 fuel,are measured under a transient cycle and steady modes.The impacts of a three-way catalyst （TWC） are investigated for the two types of fuels.The measured results show that NOx and acetaldehyde emitted from the E10-fueled car are much more than that from the gasoline-fueled car under the same modes.On the basis of maximum incremental reactivity （MIR） factors and emissions of organic gases,the ozone specific reactivity of the tailpipe gases are evaluated.展开更多
Optimization procedures are required to minimize the amount of fuel consumption and exhaust emissions from marine engines.This study discusses the procedures to optimize the performance of any marine engine implemente...Optimization procedures are required to minimize the amount of fuel consumption and exhaust emissions from marine engines.This study discusses the procedures to optimize the performance of any marine engine implemented in a 0D/1D numerical model in order to achieve lower values of exhaust emissions.From that point,an extension of previous simulation researches is presented to calculate the amount of SOx emissions from two marine diesel engines along their load diagrams based on the percentage of sulfur in the marine fuel used.The variations of SOx emissions are computed in g/k W·h and in parts per million(ppm)as functions of the optimized parameters:brake specific fuel consumption and the amount of air-fuel ratio respectively.Then,a surrogate model-based response surface methodology is used to generate polynomial equations to estimate the amount of SOx emissions as functions of engine speed and load.These developed non-dimensional equations can be further used directly to assess the value of SOx emissions for different percentages of sulfur of the selected or similar engines to be used in different marine applications.展开更多
yb3＋/Dy3＋ co-doped A1203 nanopowders have been prepared by the non-aqueous sol-gel method and their up- conversion photoluminescence spectra are measured under excitation by a 980-nm semiconductor laser. The results...yb3＋/Dy3＋ co-doped A1203 nanopowders have been prepared by the non-aqueous sol-gel method and their up- conversion photoluminescence spectra are measured under excitation by a 980-nm semiconductor laser. The results show that there are comparatively abundant spectra of up-conversion emissions centered at 378, 408, 527 and 543, and 663 nm, corresponding to 4C9/2→ 6H13/2, 4C9/2→ 6Hll/2, 4115/2 → 6H13/2, and 4F9/2 →6Hll/2 transitions of Dy3＋, respectively. Two-photon and three-photon processes are involved in ultraviolet, violet, green, and red up-conversion emissions. The energy transition between Yb3＋ and Dy3＋ is discussed.展开更多
基金funded by the National Natural Science Foundation of China (Grant No. 11875031)the key research projects of Natural Science of Anhui Provincial Colleges and Universities (Grant No. 2022AH050252)。
文摘As a common transportation facility, speed humps can control the speed of vehicles on special road sections to reduce traffic risks. At the same time, they also cause instantaneous traffic emissions. Based on the classic instantaneous traffic emission model and the limited deceleration capacity microscopic traffic flow model with slow-to-start rules, this paper has investigated the impact of speed humps on traffic flow and the instantaneous emissions of vehicle pollutants in a single lane situation. The numerical simulation results have shown that speed humps have significant effects on traffic flow and traffic emissions. In a free-flow region, the increase of speed humps leads to the continuous rise of CO_(2), NO_(X) and PM emissions. Within some density ranges, one finds that these pollutant emissions can evolve into some higher values under some random seeds. Under other random seeds, they can evolve into some lower values. In a wide moving jam region, the emission values of these pollutants sometimes appear as continuous or intermittent phenomenon. Compared to the refined Na Sch model, the present model has lower instantaneous emissions such as CO_(2), NO_(X) and PM and higher volatile organic components(VOC) emissions. Compared to the limited deceleration capacity model without slow-to-start rules, the present model also has lower instantaneous emissions such as CO_(2), NO_(X) and PM and higher VOC emissions in a wide moving jam region. These results can also be confirmed or explained by the statistical values of vehicle velocity and acceleration.
基金Project supported by the National Natural Science Foundation of China(Grant No.52172314)the Natural Science Foundation of Liaoning Province,China(Grant No.2022-MS-150)the Special Funding Project of Taishan Scholar Engineering.
文摘This paper investigates the impacts of a bus holding strategy on the mutual interference between buses and passenger cars in a non-dedicated bus route,as well as the impacts on the characteristics of pollutant emissions of passenger cars.The dynamic behaviors of these two types of vehicles are described using cellular automata(CA)models under open boundary conditions.Numerical simulations are carried out to obtain the phase diagrams of the bus system and the trajectories of buses and passenger cars before and after the implementation of the bus holding strategy under different probabilities of passenger cars entering a two-lane mixed traffic system.Then,we analyze the flow rate,satisfaction rate,and pollutant emission rates of passenger cars together with the performance of a mixed traffic system.The results show that the bus holding strategy can effectively alleviate bus bunching,whereas it has no significant impact on the flow rate and pollutant emission rates of passenger cars;the flow rate,satisfaction rate,and pollutant emission rates of passenger cars for either the traffic system or for each lane are influenced by the bus departure interval and the number of passengers arriving at bus stops.
文摘This study aims to analysis the influence of economic growth(EG)and energy consumption(EC)on sulfur dioxide emissions(SE)in China.Accordingly,this study explores the link between EG,EC,and SE for 30 provinces in China over the span of 2000-2019.This study also analyzes cross-sectional dependence tests,panel unit root tests,Westerlund panel cointegration tests,Dumitrescu-Hurlin(D-H)causality tests.According to the test results,there is an inverted U-shaped association between EG and SE,and the assumption of the Environmental Kuznets Curve(EKC)is verified.The signs of EG and EC in the fixed effect(FE)and random effect(RE)methods are in line with those in the dynamic ordinary least squares(DOLS),fully modified ordinary least squares(FMOLS)and autoregressive distributed lag(ARDL)estimators.Moreover,the results verified that EC can obviously positive impact the SE.To reduce SE in China,government and policymakers can improve air quality by developing cleaner energy sources and improving energy efficiency.This requires the comprehensive use of policies,regulations,economic incentives,and public participation to promote sustainable development.
基金Open Access funding enabled and organized by CAUL and its Member Institutions
文摘Investing in projects that support environmental benefits,such as tree harvesting,has the potential to reduce air pollution levels in the atmosphere in the future.However,this kind of investment may increase the current level of emissions.Therefore,it is necessary to estimate how much the policy affects the current level of CO_(2) emissions.This makes sure the policy doesn’t increase the level of CO_(2) emis-sions.This study aims to analyze the effect of the One Bil-lion Trees program on CO_(2) emissions in New Zealand by employing the 2020 input–output table analysis.This inves-tigation examines the direct and indirect effects of policy on both the demand and supply sides across six regions of New Zealand.The results of this study for the first year of plantation suggest that the policy increases the level of CO_(2) emissions in all regions,especially in the Waikato region.The direct and indirect impact of the policy leads to 64 kt of CO_(2) emissions on the demand side and 270 kt of CO_(2) emis-sions on the supply side.These lead to 0.19 and 0.74%of total CO_(2) emissions being attributed to investment shocks.Continuing the policy is recommended,as it has a low effect on CO_(2) emissions.However,it is crucial to prioritize the use of low-carbon machinery that uses fossil fuels during the plantation process.
基金Project supported by the National Key Research and Development Program of China(Grant No.2020YFC2201001)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2019B030302001)+1 种基金the National Natural Science Foundation of China(Grant Nos.12105373,12105374,and 11927812)the Science and Technology Research Project of Jiangxi Provincial Department of Education(Grant No.GJJ2402105).
文摘Accurate thrust assessment is crucial for characterizing the performance of micro-thrusters.This paper presents a comprehensive evaluation of the thrust generated by a needle-type indium field emission electric propulsion(In-FEEP)micro-thruster using three methods based on a pendulum:direct thrust measurement,indirect plume momentum transfer and beam current diagnostics.The experimental setup utilized capacitive displacement sensors for force detection and a voice coil motor as a feedback actuator,achieving a resolution better than 0.1μN.Key performance factors such as ionization and plume divergence of ejected charged particles were also examined.The study reveals that the high applied voltage induces significant electrostatic interference,becoming the dominant source of error in direct thrust measurements.Beam current diagnostics and indirect plume momentum measurements were conducted simultaneously,showing strong agreement within a deviation of less than 0.2N across the operational thrust range.The results from all three methods are consistent within the error margins,verifying the reliability of the indirect measurement approach and the theoretical thrust model based on the electrical parameters of In-FEEP.
基金financially supported by Heilongjiang Postdoctoral Fund(Grant No.LBH-Z24057)Outstanding Master’s and Doctoral Thesis of Longjiang in the New Era(Grant No.LJYXL2023-076).
文摘Radiative cooling fabric creates a thermally comfortable environment without energy input,providing a sustainable approach to personal thermal management.However,most currently reported fabrics mainly focus on outdoor cooling,ignoring to achieve simultaneous cooling both indoors and outdoors,thereby weakening the overall cooling performance.Herein,a full-scale structure fabric with selective emission properties is constructed for simultaneous indoor and outdoor cooling.The fabric achieves 94%reflectance performance in the sunlight band(0.3–2.5μm)and 6%in the mid-infrared band(2.5–25μm),effectively minimizing heat absorption and radiation release obstruction.It also demonstrates 81%radiative emission performance in the atmospheric window band(8–13μm)and 25%radiative transmission performance in the mid-infrared band(2.5–25μm),providing 60 and 26 W m−2 net cooling power outdoors and indoors.In practical applications,the fabric achieves excellent indoor and outdoor human cooling,with temperatures 1.4–5.5℃ lower than typical polydimethylsiloxane film.This work proposes a novel design for the advanced radiative cooling fabric,offering significant potential to realize sustainable personal thermal management.
基金Supported by the National Natural Science Foundation of China(41101569)the China Postdoctoral Science Foundation Funded Project(2011M500965)+5 种基金the Jiangsu Funds of Social Science(11EYC023)the Doctoral Discipline New Teachers Fund(20110095120002)the Jiangsu Postdoctoral Science Foundation Funded Project(1102088C)the Fundamental Research Funds for the Central Universities(JGJ110763)the Talent Introduction Funds of China University of Mining and Technologythe Sail Plan Funds for Young Teachers of China University of Mining and Technology~~
文摘How to achieve the objective of reducing CO2 emissions has been an academic focus in China recently. The factors influencing CO2 emissions are the vital issue to accomplish the arduous target. Firstly, three influential factors, the energy consumption, the proportion of tertiary industry in gross domestic product （GDP）, and the degree of dependence on foreign trade, are carefully selected, since all of them have closer grey relation with China＇s COz emissions compared with others when the grey relational analysis （GRA） method is applied. The study highlights co-integration relation of these four variables using the co-integration analysis method. And then a long-term co-integration equation and a short-term error correction model of China＇s CO2 emissions are devel- oped. Finally, the comparison is exerted between the forecast value and the actual value of China＇s CO2 emissions based on error correction model. The results and the relevant statistics tests show that the pro- posed model has better explanation capability and credibility.
基金financially supported by Grant Projects on Clean Development Mechanism in China(No.2012076)the special basic scientific research expenses from Research Institute of Forestry New Technology,Chinese Academy of Forestry(No.CAFINT2014K06)
文摘Peatlands are one of the major natural sources of methane （CH4）, but the level of CH4 efflux is uncertain, especially in alpine peatlands. In this study, CH4 emission fluxes from natural and drained peatlands on the Qinghai- Tibet Plateau, southwest China, were measured from June to October in 2013 using the opaque static chamber technique and the Fast Greenhouse Gas Analyzer （DLT-100, Los Gatos Research Corp.）. CH4 emission fluxes ranged from 2.07 to 56.33 mg m^-2 h^-1 in natural peatlands and from 0.02 to 0.42 mg m^-2 h^-1 in drained peatlands. Mean CH4 emission flux was 19.13 mg m^-2 h^-1 in natural peatlands and 0.14 mg m^-2 h^-1 in drained peatlands. These results showed that drainage led to a significant decrease in CH4 emissions. CH4 emission fluxes for all sampling plots were significantly correlated with variation in water table depth for linear （R^2 = 0.453, P 〈 0.01） and exponential functions （R^2 = 0.429, P 〈 0.01）.
基金support of the Australian Government Research Training Program Scholarshipgratefully acknowledge the direct financial support of Me Cee Solutions Pty Ltd
文摘The prediction of gas emissions arising from underground coal mining has been the subject of extensive research for several decades, however calculation techniques remain empirically based and are hence limited to the origin of calculation in both application and resolution. Quantification and management of risk associated with sudden gas release during mining(outbursts) and accumulation of noxious or combustible gases within the mining environment is reliant on such predictions, and unexplained variation correctly requires conservative management practices in response to risk. Over 2500 gas core samples from two southern Sydney basin mines producing metallurgical coal from the Bulli seam have been analysed in various geospatial context including relationships to hydrological features and geological structures. The results suggest variability and limitations associated with the present traditional approaches to gas emission prediction and design of gas management practices may be addressed using predictions derived from improved spatial datasets, and analysis techniques incorporating fundamental physical and energy related principles.
基金funded jointly by National Science and Technology Major Project under Grant No.2016ZX05016005-003the National Natural Science Foundation of China under Grant No.71173200the Development and Research Center of China Geological Survey under Grant No.12120114056601
文摘Climate change and carbon emissions are major problems which are attracting worldwide attention. China has had its pilot carbon emission trading markets in seven regions for more than 3 years. What affects carbon emission trading market in China is a big question. More attention is paid to how China promotes the carbon emission trading schemes in the whole country. This paper addresses concerns about the functioning of carbon emission trading schemes in seven pilot regions and takes the weekly data from November 25, 2013, to March 19, 2017. We employ a vector autoregressive model to study how coal price, oil price and stock index have affected the carbon price in China. The results indicate that carbon price is mainly affected by its own historical price; coal price and stock index have negative effects on carbon price, while oil price has a negative effect on carbon price during the first 3 weeks and then has a positive effect on carbon price. More regulatory attention and economic measures are needed to improve market efficiency, and the mechanisms of carbon emission trading schemes should be improved.
基金Angpanneföreningen’s Foundation for Research and Development(11-164)the Foundation for Swedish Environmental Research Institute(SIVL)Swedish Maritime Organization and Lighthouse for their financial support
文摘The fuel sulfur content in marine fuels has been regulated in Sulfur Emission Control Areas(SECAs) since January 2015. However, other fuel characteristics are also believed to have an impact on particle emissions, particularly on the number of particles emitted. This study investigates the impact of the content of aromatics in fuel. To achieve fuel blends with concentrations of aromatics similar to those found in marine fuel oils, i.e. 20%–30% by volume(%vol.), normal diesel oil(4%–5% vol. aromatics) is doped with a mixture of aromatics. Emission measurements are conducted in test-bed engine facilities and particle emissions over a wide size range are analyzed. Results show a decreased number of particles emitted(or not change) with an increase in the aromatic concentration in fuel. This is because there is a reduction in the cetane number of the fuel with an increased aromatic content, which effects the combustion process and results in decreased particle formation. However, when ignition improver is used to increase the cetane number, particle emissions remain at a lower level than for normal diesel oil; thereby emphasizing the presence of other factors in the formation of particles.
基金supported by the Alliance for Global Sustainability promotional office at the University of Tokyo
文摘Hurricanes cause abrupt carbon reduction in forests, but silviculture treatment can be an effective means of quickly regenerating and restoring hurricane-damaged sites. This study assessed how silviculture treatments affect carbon balance after hurricane damage in central Hokkaido, Japan. We examined carbon storage in trees and underground vegetation as well as carbon emissions from silviculture operations in 25-year-old stands, where scarification and plantation occurred just after hurricane damage. The amount of carbon stored varied according to silviculture treatment. Among three scarification treatments, a scarified depth of 0 cm （understory vegetation removal） led to the largest amount of carbon stored （64.7 t·ha^-1 C）. Among four plantation treatments, the largest amount of carbon was stored in a Larix hybrid （L. gmelinii var. japonica × L. kaempferi） plantation （80.3 t·ha^-1 C）. The plantation of Abies sachalinensis was not successful at accumulating carbon （40.5·ha^-1 C）. The amount of carbon emitted from silviculture operations was 0.05-0.14 t·ha^-1 C, and it marginally affected the net carbon balance of the silviculture project. Results indicate that silviculture treatments should beperformed in an appropriate way to effectively recover the ability of carbon sequestration in hurricane-damaged forests.
基金Project supported by the National Natural Science Foundation of China (Grant No 60477023)the Natural Science Foundation of Science and Technology Commission of Liaoning Province, China (Grant No 20062137)
文摘The green and red up-conversion emissions centred at about 534, 549 and 663 nm of wavelength, corresponding respectively to the ^2H11/2 → ^4I15/2, ^4S3/2 → ^4I15/2 and ^4F9/2 → ^4I15/2 transitions of Er^3＋ ions, have been observed for the Er^3＋-doped silicate glass excited by a 978 nm semiconductor laser beam. Excitation power dependent behaviour of the up-conversion emission intensity indicates that a two-photon absorption up-conversion process is responsible for the green and red up-conversion emissions. The temperature dependence of the green up-conversion emissions is also studied in a temperature range of 296-673 K, which shows that Er^3＋-doped silicate glass can be used as a sensor in high-temperature measurement.
文摘The progress of economic globalization,the rapid growth of international trade,and the maritime transportation has played an increasingly significant role in the international supply chain.As a result,worldwide seaports have suffered from a central problem,which appears in the form of massive amounts of fuel consumed and exhaust gas fumes emitted from the ships while berthed.Many ports have taken the necessary precautions to overcome this problem,while others still suffer due to the presence of technical and financial constraints.In this paper,the barriers,interconnection standards,rules,regulations,power sources,and economic and environmental analysis related to ships,shore-side power were studied in efforts to find a solution to overcome his problem.As a case study,this paper investigates the practicability,costs and benefits of switching from onboard ship auxiliary engines to shore-side power connection for high-speed crafts called Alkahera while berthed at the port of Safaga,Egypt.The results provide the national electricity grid concept as the best economical selection with 49.03 percent of annual cost saving.Moreover,environmentally,it could achieve an annual reduction in exhaust gas emissions of CO2,CO,NOx,P.M,and SO2by 276,2.32,18.87,0.825 and 3.84 tons,respectively.
基金the financial support from the National Natural Science Foundation of China(71473010,41701635)
文摘For studying new and renewable energy as a substitute for fossil energy in primary energy consumption and its impact on carbon emissions to cope with economic uncertainties, a multi-sector DSGE model was employed to simulate the dynamic impact on carbon emissions and macroeconomic development. The structural adjustment of energy consumption and the carbon emissions mitigation policy were considered in the model. The simulation results showed that using new and renewable energy instead of fossil energy is an optimal choice for the firms to comply with the regulations of carbon emission mitigation policy. Structural adjustment of energy consumption is the best route to achieve the dual goal of economic development and carbon emission reduction. Unexpected sharp fall in free carbon quota has a negative impact on the economy.
基金Project supported by the Shanghai Human Resources and Social Security Bureau,China(Grant No.2009023)
文摘Graphene films are deposited on copper （Cu） and aluminum （Al） substrates, respectively, by using a microwave plasma chemical vapour deposition technique. Furthermore, these graphene films are characterized by a field emission type scanning electron microscope （FE-SEM）, Raman spectra, and field emission （FE） I-V measurements. It is found that the surface morphologies of the films deposited on Cu and Al substrates are different： the field emission property of graphene film deposited on the Cu substrate is better than that on the Al substrate, and the lowest turn-on field of 2.4 V/p-m is obtained for graphene film deposited on the Cu substrate. The macroscopic areas of the graphene samples are all above 400 mm2.
文摘Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for a ferry during operation.The emission factor for nitrogen oxides is lower than what is typically found for marine gasoil but does not reach the tier III limit.The emissions of particulate matter are significantly lower than for fuel oils and similar to what is found for LNG engines.The main part of the particles can be found in the ultrafine range with the peak being at around 18 nm.About 93%of the particles are evaporated and absorbed when using a thermodenuder,and thus a large majority of the particles are volatile.Methanol is a potential future marine fuel that will reduce emissions of air pollutants and can be made as a biofuel to meet emission targets for greenhouse gases.
基金Sponsored by the National Natural Science Foundation of China (40805053)
文摘The regulated pollutants （CO,HC and NOx） and unregulated pollutants （volatile organic compounds and carbonyl compounds）,emitted from a dual fuel vehicle fueled with gasoline and E10 fuel,are measured under a transient cycle and steady modes.The impacts of a three-way catalyst （TWC） are investigated for the two types of fuels.The measured results show that NOx and acetaldehyde emitted from the E10-fueled car are much more than that from the gasoline-fueled car under the same modes.On the basis of maximum incremental reactivity （MIR） factors and emissions of organic gases,the ozone specific reactivity of the tailpipe gases are evaluated.
基金performed within the Strategic Research Plan of the Centre for Marine Technology and Ocean Engineering(CENTEC)financed by Portuguese Foundation for Science and Technology(Fundacao para a Ciência e Tecnologia(FCT)),under contract UID/Multi/00134/2013-LISBOA-01-0145-FEDER-007629。
文摘Optimization procedures are required to minimize the amount of fuel consumption and exhaust emissions from marine engines.This study discusses the procedures to optimize the performance of any marine engine implemented in a 0D/1D numerical model in order to achieve lower values of exhaust emissions.From that point,an extension of previous simulation researches is presented to calculate the amount of SOx emissions from two marine diesel engines along their load diagrams based on the percentage of sulfur in the marine fuel used.The variations of SOx emissions are computed in g/k W·h and in parts per million(ppm)as functions of the optimized parameters:brake specific fuel consumption and the amount of air-fuel ratio respectively.Then,a surrogate model-based response surface methodology is used to generate polynomial equations to estimate the amount of SOx emissions as functions of engine speed and load.These developed non-dimensional equations can be further used directly to assess the value of SOx emissions for different percentages of sulfur of the selected or similar engines to be used in different marine applications.
基金Project supported by the National Natural Science Foundation of China （Grant No. 11004092） and the Scientific Research Fund of Education Department of Liaoning Province, China （Grant No. 2009A417）.
文摘yb3＋/Dy3＋ co-doped A1203 nanopowders have been prepared by the non-aqueous sol-gel method and their up- conversion photoluminescence spectra are measured under excitation by a 980-nm semiconductor laser. The results show that there are comparatively abundant spectra of up-conversion emissions centered at 378, 408, 527 and 543, and 663 nm, corresponding to 4C9/2→ 6H13/2, 4C9/2→ 6Hll/2, 4115/2 → 6H13/2, and 4F9/2 →6Hll/2 transitions of Dy3＋, respectively. Two-photon and three-photon processes are involved in ultraviolet, violet, green, and red up-conversion emissions. The energy transition between Yb3＋ and Dy3＋ is discussed.
