In modern society, the level of science and technology changes with the changes of the times. Science and technology are widely used in various industries and also play a very important role. The online automatic dete...In modern society, the level of science and technology changes with the changes of the times. Science and technology are widely used in various industries and also play a very important role. The online automatic detection and monitoring system for environmental pollution sources is an embodiment of adopting advanced environmental protection technology. In practice, the system is mainly based on complex technologies such as computer technology and sensors to detect the source of pollutants. With the application of advanced technology for many times, the practical application of this system becomes more and more common. Based on this, this paper discusses the relevant contents of the online automatic monitoring and control management system for environmental pollution sources.展开更多
Based on the decoupiing theory and method, an indicator system was built for the relation between economic development level and resource and environment carrying capacity. And the study was carried out on decoupling ...Based on the decoupiing theory and method, an indicator system was built for the relation between economic development level and resource and environment carrying capacity. And the study was carried out on decoupling degree and temporal changes of economic development level and resource and environment carrying ca- pacity in the central area of Yunnan Province. Results indicated that （i） the economic development level and resource and environment carrying capacity in the central area of Yunnan Province mainly experienced strong decoupling, weak decoupling, and ex- pansive negative coupling, and in general it was strong decoupling, and it took on re- verse ＂N＂ in temporal changes. （ii） Change rate of economic development level in the central area of Yunnan Province was greater than zero, but the amplitude of change was not large, while the change rate of resource and environment carrying capacity was negative in 2007-2008, and it was positive in the rest years; from 2007, it took on gradual expansion trend, and scissors difference gradually increased after experi- encing reverse ＂V＂ change. （iii） The strong decoupling was the main situation and it reached the peak value in T5 period and T6 pedod.展开更多
Atmospheric deposition, a major pathway of metals entering into soils, plays an important role in soil environment, especially in urban regions where a large amount of pollutants are emitted into atmosphere through va...Atmospheric deposition, a major pathway of metals entering into soils, plays an important role in soil environment, especially in urban regions where a large amount of pollutants are emitted into atmosphere through various sources. In order to understand the characteristics of atmospheric deposition in urban area and its relation with natural and anthropogenic sources, a three-year study of atmospheric deposition at three typical sites, industrial zone(IN), urban residential area(RZ) and suburban forested scenic area(FA),was carried out in Nanjing, a metropolitan city in eastern China from 2005 to 2007. The bulk deposition rate and element composition of atmospheric deposition varied spatio-temporally in the urban zones of Nanjing. The concentrations of Cu, Zn, Pb and Ca in the atmospheric deposits were strongly enriched in the whole Nanjing region; however, anthropogenic pollutants in atmospheric deposits were diluted by the input of external mineral dust transported from northwestern China. Source apportionment through principal component analysis(PCA) showed that the background atmospheric deposition at the FA site was the combination of external aerosol and local emission sources. The input of long-range transported Asian dust had an important influence on the urban background deposition, especially in spring when the continental dust from the northwestern China prevailed. Marine aerosol source was observed in summer and autumn, the seasons dominated by summer monsoon in Nanjing. In contrast, the contribution of local anthropogenic emission source was constant regardless of seasons. At the RZ and IN sites, the atmospheric deposition was more significantly affected by the nearby human activities than at the FA site. In addition, different urban activities and both the winter and summer Asian monsoons had substantial impacts on the characteristics of dust deposition in urban Nanjing.展开更多
Objective The distribution of rearranged hopanes in hydrocarbon source rocks is influenced by thermal maturity and original source input, and is also controlled by depositional conditions. Through comparison of lacus...Objective The distribution of rearranged hopanes in hydrocarbon source rocks is influenced by thermal maturity and original source input, and is also controlled by depositional conditions. Through comparison of lacustrine and coal-bearing source rocks, this work attempted to analyze the composition and origin of rearranged hopanes in hydrocarbon source rocks. Taken the source rocks from the Songliao Basin, Ordos Basin and Kuqa Depression as examples, we aimed to investigate the effect of the redox conditions, water salinity and oxygen content of the source-rock depositional environment on the formation of rearranged hopanes to provide theoretical basis for the genesis of rearranged hopanes.展开更多
The Songliao Basin, one of the biggest continental petroliferous basins in eastern China, is a Mesozoic- Cenozoic fault-depressed and fault-subsided basin developed on the Hercynian fold basement. Generally, rearrange...The Songliao Basin, one of the biggest continental petroliferous basins in eastern China, is a Mesozoic- Cenozoic fault-depressed and fault-subsided basin developed on the Hercynian fold basement. Generally, rearranged hopanes are considered to be formed by clay- mediated acidic catalysis under oxic or suboxic environment, whereas high abundance of rearranged hopanes were found in hydrocarbon source rocks and crude oils that are derived from salty environment in the Songliao Basin. This phenomenon rarely happens all over the world.展开更多
A compact mirror-like ECR (electron cyclotron resonance) Plasma source for the ionosphere environment simulator was described for the fort time in China. The Overall sources system was composed of a 200 W 2.45 GHz mic...A compact mirror-like ECR (electron cyclotron resonance) Plasma source for the ionosphere environment simulator was described for the fort time in China. The Overall sources system was composed of a 200 W 2.45 GHz microwave source, a coastal 3A./4 TEM-mode microwave resonance applicator, column and cylindrical Nd-Fe-P magnets, a quartz bell-shaped discharge chamber, a gas inlet system and a plasma-diffusing bore. The preliminary experiment demonstrated that ambi-polar diffusion plasma stream into the simulator (-500 mm long) formed an environment with following parameters: a plasma density ne of 104 cm-3 - 106 cm-3, an electron temperature Te < 5 eV at a pressure P of 10-1 Pa-10-3 Pa, a Plasma uniformity of > 80% over the experimental target with a 160-mm-in-diameter, satisfying primarily the requirement of simulating in a severe ionosphere environment.展开更多
As the international trading system has developed with the division of Global value Chains (GVCS), the export trade of Brazil, Russia, India, China, and South Africa (BRICS) has grown rapidly. The resulting growth of ...As the international trading system has developed with the division of Global value Chains (GVCS), the export trade of Brazil, Russia, India, China, and South Africa (BRICS) has grown rapidly. The resulting growth of carbon emissions has drawn wide attention from the international community, necessitating the comparison of the trade benefits and environmental costs of the BRICS participation in GVCS. Based on the Eora database, this paper constructs a decomposition framework for the calculation of export value-added and embodied carbon, based on a multi-region input-output (MRIO) model. The trade benefits and environmental costs paid by the BRICS’ total exports from 1990 to 2015 were measured and the imbalance was analyzed, along with the causes. The results show that the main value-added and carbon embodied in the BRICS’ exports originate from their own countries, and the domestic value-added content of the BRICS’ exports decreased while the foreign value-added content increased.展开更多
Ultra-stable piezoelectric nanogenerator(PENG)driven by environmental actuation sources with all-weather service capability is highly desirable.Here,the PENG based on N doped 4H-SiC nanohole arrays(NHAs)is proposed to...Ultra-stable piezoelectric nanogenerator(PENG)driven by environmental actuation sources with all-weather service capability is highly desirable.Here,the PENG based on N doped 4H-SiC nanohole arrays(NHAs)is proposed to harvest ambient energy under low/high temperature and relative humidity(RH)conditions.Finite element method simulation of N doped 4H-SiC NHAs in compression mode is developed to evaluate the relationship between nanohole diameter and piezoelectric performance.The density of short circuit current of the assembled PENG reaches 313 nA cm^(-2),which is 1.57 times the output of PENG based on N doped 4H-SiC nanowire arrays.The enhancement can be attributed to the existence of nanohole sidewalls in NHAs.All-weather service capability of the PENG is verified after being treated at-80/80℃and 0%/100%RH for 50 days.The PENG is promising to be widely used in practice worldwide to harvest biomechanical energy and mechanical energy.展开更多
In this paper we investigate three novel rising submillimeter （THz） bursts that occurred sequen- tially in Super Active Region NOAA 10486. The average rising rate of the flux density above 200 GHz is only 20 sfu GHz...In this paper we investigate three novel rising submillimeter （THz） bursts that occurred sequen- tially in Super Active Region NOAA 10486. The average rising rate of the flux density above 200 GHz is only 20 sfu GHz-1 （corresponding to spectral index α of 1.6） for the THz spectral components of the 2003 October 28 and November 4 bursts, but it attained values of 235 sfu GHz-1 （α = 4.8） in the 2003 November 2 burst. The steeply rising THz spectrum can be produced by a population of highly relativistic electrons with a low-energy cutoff of 1 MeV, but it only requires a low-energy cutoff of 30 keV for the two slowly rising THz bursts, via gyrosynchrotron （GS） radiation based on our numerical simulations of burst spectra in the magnetic dipole field case. The electron density variation is much larger in the THz source than in the microwave （MW） source. It is interesting that the THz source radius decreased by 20%-50% during the decay phase for the three events, but the MW source increased by 28% for the 2003 November 2 event. In the paper we will present a formula that can be used to calculate the energy released by ultrarel- ativistic electrons, taking the relativistic correction into account for the first time. We find that the energy released by energetic electrons in the THz source exceeds that in the MW source due to the strong GS radi- ation loss in the THz range, although the modeled THz source area is 3-4 orders smaller than the modeled MW source one. The total energies released by energetic electrons via the GS radiation in radio sources are estimated, respectively, to be 5.2 × 10^33, 3.9 × 10^33 and 3.7 × 10^32 erg for the October 28, November 2 and 4 bursts, which are 131, 76 and 4 times as large as the thermal energies of 2.9 × 10^31, 2.1 × 10^31 and 5.2 × 10^31 erg estimated from soft X-ray GOES observations.展开更多
The transition to sustainable and environmentally friendly energy sources is a crucial step in our global effort to reduce carbon emissions.In this context,fuel cell technology has emerged as a leading innovative solu...The transition to sustainable and environmentally friendly energy sources is a crucial step in our global effort to reduce carbon emissions.In this context,fuel cell technology has emerged as a leading innovative solution,offering a promising alternative to conventional fossil fuel-based systems.It aims to achieve zero emissions while maintaining high efficiency and performance.Although fuel cell technology holds great potential for a sustainable and clean energy future,its widespread adoption is still hindered by several challenges.These include improving the efficiency and durability of fuel cells,as well as further enhancing their power output.To address these challenges,various design innovations and optimization strategies have been proposed to tackle the practical issues encountered in real-world applications.This special issue aims to provide a platform for researchers,engineers,and policymakers to present their latest scientific findings or engineering experiences in the development and application of new technologies to overcome the challenges in fuel cell application.展开更多
文摘In modern society, the level of science and technology changes with the changes of the times. Science and technology are widely used in various industries and also play a very important role. The online automatic detection and monitoring system for environmental pollution sources is an embodiment of adopting advanced environmental protection technology. In practice, the system is mainly based on complex technologies such as computer technology and sensors to detect the source of pollutants. With the application of advanced technology for many times, the practical application of this system becomes more and more common. Based on this, this paper discusses the relevant contents of the online automatic monitoring and control management system for environmental pollution sources.
基金Supported by Scientific Research Foundation of Yunnan Provincial Department of Education(2015J088)~~
文摘Based on the decoupiing theory and method, an indicator system was built for the relation between economic development level and resource and environment carrying capacity. And the study was carried out on decoupling degree and temporal changes of economic development level and resource and environment carrying ca- pacity in the central area of Yunnan Province. Results indicated that （i） the economic development level and resource and environment carrying capacity in the central area of Yunnan Province mainly experienced strong decoupling, weak decoupling, and ex- pansive negative coupling, and in general it was strong decoupling, and it took on re- verse ＂N＂ in temporal changes. （ii） Change rate of economic development level in the central area of Yunnan Province was greater than zero, but the amplitude of change was not large, while the change rate of resource and environment carrying capacity was negative in 2007-2008, and it was positive in the rest years; from 2007, it took on gradual expansion trend, and scissors difference gradually increased after experi- encing reverse ＂V＂ change. （iii） The strong decoupling was the main situation and it reached the peak value in T5 period and T6 pedod.
基金supported by the National Natural Science Foundation of China(Nos.41130530 and 40625001)
文摘Atmospheric deposition, a major pathway of metals entering into soils, plays an important role in soil environment, especially in urban regions where a large amount of pollutants are emitted into atmosphere through various sources. In order to understand the characteristics of atmospheric deposition in urban area and its relation with natural and anthropogenic sources, a three-year study of atmospheric deposition at three typical sites, industrial zone(IN), urban residential area(RZ) and suburban forested scenic area(FA),was carried out in Nanjing, a metropolitan city in eastern China from 2005 to 2007. The bulk deposition rate and element composition of atmospheric deposition varied spatio-temporally in the urban zones of Nanjing. The concentrations of Cu, Zn, Pb and Ca in the atmospheric deposits were strongly enriched in the whole Nanjing region; however, anthropogenic pollutants in atmospheric deposits were diluted by the input of external mineral dust transported from northwestern China. Source apportionment through principal component analysis(PCA) showed that the background atmospheric deposition at the FA site was the combination of external aerosol and local emission sources. The input of long-range transported Asian dust had an important influence on the urban background deposition, especially in spring when the continental dust from the northwestern China prevailed. Marine aerosol source was observed in summer and autumn, the seasons dominated by summer monsoon in Nanjing. In contrast, the contribution of local anthropogenic emission source was constant regardless of seasons. At the RZ and IN sites, the atmospheric deposition was more significantly affected by the nearby human activities than at the FA site. In addition, different urban activities and both the winter and summer Asian monsoons had substantial impacts on the characteristics of dust deposition in urban Nanjing.
基金financed by the National Science Foundation of China(grant No.41272170)the National Oil and Gas Major Project(grant No.2016ZX05007-001)
文摘Objective The distribution of rearranged hopanes in hydrocarbon source rocks is influenced by thermal maturity and original source input, and is also controlled by depositional conditions. Through comparison of lacustrine and coal-bearing source rocks, this work attempted to analyze the composition and origin of rearranged hopanes in hydrocarbon source rocks. Taken the source rocks from the Songliao Basin, Ordos Basin and Kuqa Depression as examples, we aimed to investigate the effect of the redox conditions, water salinity and oxygen content of the source-rock depositional environment on the formation of rearranged hopanes to provide theoretical basis for the genesis of rearranged hopanes.
基金supported by the National Natural Science Foundation of China(grant No.41272170)
文摘The Songliao Basin, one of the biggest continental petroliferous basins in eastern China, is a Mesozoic- Cenozoic fault-depressed and fault-subsided basin developed on the Hercynian fold basement. Generally, rearranged hopanes are considered to be formed by clay- mediated acidic catalysis under oxic or suboxic environment, whereas high abundance of rearranged hopanes were found in hydrocarbon source rocks and crude oils that are derived from salty environment in the Songliao Basin. This phenomenon rarely happens all over the world.
文摘A compact mirror-like ECR (electron cyclotron resonance) Plasma source for the ionosphere environment simulator was described for the fort time in China. The Overall sources system was composed of a 200 W 2.45 GHz microwave source, a coastal 3A./4 TEM-mode microwave resonance applicator, column and cylindrical Nd-Fe-P magnets, a quartz bell-shaped discharge chamber, a gas inlet system and a plasma-diffusing bore. The preliminary experiment demonstrated that ambi-polar diffusion plasma stream into the simulator (-500 mm long) formed an environment with following parameters: a plasma density ne of 104 cm-3 - 106 cm-3, an electron temperature Te < 5 eV at a pressure P of 10-1 Pa-10-3 Pa, a Plasma uniformity of > 80% over the experimental target with a 160-mm-in-diameter, satisfying primarily the requirement of simulating in a severe ionosphere environment.
文摘As the international trading system has developed with the division of Global value Chains (GVCS), the export trade of Brazil, Russia, India, China, and South Africa (BRICS) has grown rapidly. The resulting growth of carbon emissions has drawn wide attention from the international community, necessitating the comparison of the trade benefits and environmental costs of the BRICS participation in GVCS. Based on the Eora database, this paper constructs a decomposition framework for the calculation of export value-added and embodied carbon, based on a multi-region input-output (MRIO) model. The trade benefits and environmental costs paid by the BRICS’ total exports from 1990 to 2015 were measured and the imbalance was analyzed, along with the causes. The results show that the main value-added and carbon embodied in the BRICS’ exports originate from their own countries, and the domestic value-added content of the BRICS’ exports decreased while the foreign value-added content increased.
基金This work was supported by the National Science Fund for Distinguished Young Scholars(No.52025041)the National Natural Science Foundation of China(No.51974021,51902020,51904021)+2 种基金the Fundamental Research Funds for the Central Universities of NO.FRF-TP-18-045A1 and FRF-TP-19-004B2Zthe National Postdoctoral Program for Innovative Talents(BX20180034)This project is supported by open foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials,Guangxi University(Grant No.2021GXYSOF12).
文摘Ultra-stable piezoelectric nanogenerator(PENG)driven by environmental actuation sources with all-weather service capability is highly desirable.Here,the PENG based on N doped 4H-SiC nanohole arrays(NHAs)is proposed to harvest ambient energy under low/high temperature and relative humidity(RH)conditions.Finite element method simulation of N doped 4H-SiC NHAs in compression mode is developed to evaluate the relationship between nanohole diameter and piezoelectric performance.The density of short circuit current of the assembled PENG reaches 313 nA cm^(-2),which is 1.57 times the output of PENG based on N doped 4H-SiC nanowire arrays.The enhancement can be attributed to the existence of nanohole sidewalls in NHAs.All-weather service capability of the PENG is verified after being treated at-80/80℃and 0%/100%RH for 50 days.The PENG is promising to be widely used in practice worldwide to harvest biomechanical energy and mechanical energy.
基金supported by the National Natural Science Foundation of China(Grant Nos.11333009 and 11573072)the"973"program(No.2014CB744200)
文摘In this paper we investigate three novel rising submillimeter （THz） bursts that occurred sequen- tially in Super Active Region NOAA 10486. The average rising rate of the flux density above 200 GHz is only 20 sfu GHz-1 （corresponding to spectral index α of 1.6） for the THz spectral components of the 2003 October 28 and November 4 bursts, but it attained values of 235 sfu GHz-1 （α = 4.8） in the 2003 November 2 burst. The steeply rising THz spectrum can be produced by a population of highly relativistic electrons with a low-energy cutoff of 1 MeV, but it only requires a low-energy cutoff of 30 keV for the two slowly rising THz bursts, via gyrosynchrotron （GS） radiation based on our numerical simulations of burst spectra in the magnetic dipole field case. The electron density variation is much larger in the THz source than in the microwave （MW） source. It is interesting that the THz source radius decreased by 20%-50% during the decay phase for the three events, but the MW source increased by 28% for the 2003 November 2 event. In the paper we will present a formula that can be used to calculate the energy released by ultrarel- ativistic electrons, taking the relativistic correction into account for the first time. We find that the energy released by energetic electrons in the THz source exceeds that in the MW source due to the strong GS radi- ation loss in the THz range, although the modeled THz source area is 3-4 orders smaller than the modeled MW source one. The total energies released by energetic electrons via the GS radiation in radio sources are estimated, respectively, to be 5.2 × 10^33, 3.9 × 10^33 and 3.7 × 10^32 erg for the October 28, November 2 and 4 bursts, which are 131, 76 and 4 times as large as the thermal energies of 2.9 × 10^31, 2.1 × 10^31 and 5.2 × 10^31 erg estimated from soft X-ray GOES observations.
文摘The transition to sustainable and environmentally friendly energy sources is a crucial step in our global effort to reduce carbon emissions.In this context,fuel cell technology has emerged as a leading innovative solution,offering a promising alternative to conventional fossil fuel-based systems.It aims to achieve zero emissions while maintaining high efficiency and performance.Although fuel cell technology holds great potential for a sustainable and clean energy future,its widespread adoption is still hindered by several challenges.These include improving the efficiency and durability of fuel cells,as well as further enhancing their power output.To address these challenges,various design innovations and optimization strategies have been proposed to tackle the practical issues encountered in real-world applications.This special issue aims to provide a platform for researchers,engineers,and policymakers to present their latest scientific findings or engineering experiences in the development and application of new technologies to overcome the challenges in fuel cell application.
