As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural...As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural antioxidant, which has undisputable protectiveaction against free radical damages. In order to ascertain whether their combination could affordbetter effect, we have investigated the prophylactic effect of the couplant ascorbate-lysine inliver injuries.展开更多
Riverine carbon flux is an important component of the global carbon cycle. The spatial and temporal variations of organic and inorganic carbon were examined during both dry and wet seasons in the Yellow River estuary....Riverine carbon flux is an important component of the global carbon cycle. The spatial and temporal variations of organic and inorganic carbon were examined during both dry and wet seasons in the Yellow River estuary. Concentrations of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in the Yellow River during dry seasons were higher than those during wet seasons. The effective concentrations of DOC (CDOC*) were higher than the observed DOC at zero salinity. This input of DOC in the Yellow River estuary was due to sediment desorption processes in low salinity regions. In contrast to DOC, the effective concen- trations of DIC were 10% lower than the DIC measured at freshwater end, and the loss of DIC was caused by CaCO3 precipitation in low salinity region, Particulate organic carbon (POC) and particulate inorganic carbon (PIC) contents of the particles stabilized to constant values (0.5%:t:0.05% and 1.8%--0.2%, respectively) within the turbidity maximum zone (TMZ) and showed no noticeable seasonal variations. A rapid drop of PIC and rise of POC occurred simultaneously outside the TMZ due to an intense dilution of riv- erine inorganic-rich particles being transported into a pool of aquatic organic-poor particles outside the TMZ. Annually, the Yellow River transported 6.95× 10^5 t of DIC, 0.64× 10^5 t of DOC, 78.58× 10^5 t of PIC and 2.29× 10^5 t of POC to the sea.展开更多
The eutrophication, hypoxia and coastal acidification are attracting more and more attention. In this study, inorganic carbon parameters, including dissolved inorganic carbon (DIC), total alkalinity (TA) and calcu...The eutrophication, hypoxia and coastal acidification are attracting more and more attention. In this study, inorganic carbon parameters, including dissolved inorganic carbon (DIC), total alkalinity (TA) and calculated partial pressure of CO2 (pCO2), obtained from a summer cruise in August, 2009, were used to investigate their integrated response to biological processes accompanying the oxygen depletion in the areas off the Changjiang Estuary. According to the observations, the typical hypoxia occurred in the bottom water just outside the Changjiang Estuary with Dissolved Oxygen (DO) lower than 2.00 mg L^-1. The biological uptake in the surface water and the decomposition of organic matter in the bottom water were fully coupled with each other. The high concentration of Chl_a (Chl_a = 10.9μgL^-1) and DO (9.25 mgL^-1), profoundly decreased DIC concentration 0828 μmolkg^-1) and elevated pH (8.42) was observed in the surface water. The correspondingly increased DIC and depletion of oxygen were observed in the bottom water. The semi-quantitative analysis proved that the locally-produced phytoplankton, determined by primary productivity, was deposited to the bottom and contributed about 76% of total amount of the organic carbon decomposition in the bottom. However, in the bottom hypoxia (DO = 2.05 mgL^-1) area observed in the Southern Zhejiang coastal water, the responding patterns of inorganic carbon parameters deviated from the previous one. The expanding of Changjiang Diluted Water (CDW), the adding of Hangzhou Bay water (with high DIC concentration) and Coastal Current together modify the DIC background value in this area, and the local degeneration and upwelling process may also help to offset the local DIC removed by net biological uptake in surface water. In addition when the mixing occurring in autumn, which may break the summer stratification, the excess release of high DIC in the bottom water to the subsurface water could have an important influence on coastal acidification and the CO2 uptake capacity in this area.展开更多
The activated carbon wound supercapacitors with TEABF4/propylene carbonate (PC) and TEABF4/acetonitrile (AN) electrolytes were prepared. The effects of the electrolyte and temperature on the capacitance behavior w...The activated carbon wound supercapacitors with TEABF4/propylene carbonate (PC) and TEABF4/acetonitrile (AN) electrolytes were prepared. The effects of the electrolyte and temperature on the capacitance behavior were investigated by cyclic voltammetry (CV) and constant current charge-discharge. Compared with the PC-based supercapacitor, the AN-based supercapacitor has higher capacitance and lower equivalent serial resistance (RES) at discharge currents ranging from 5 to 1 000 mA and 25 ℃. Moreover, temperature effects are more prominent for PC-based supercapacitor than for AN-based supereapacitor. When the measurement temperature ranges from 60 ℃to -40 ℃ the capacitance changes from 5.1 to 2.5 F and RES changes from 135 to 876 mΩ for the PC-based supercapacior, while the AN-based supercapacitor shows less change in capacitance and RES. Thus AN-based supercapacitor exhibits excellent power characteristics and temperature property.展开更多
Coastal wetlands play an important role in the global carbon cycle. Large quantities of sediment deposited in the Changjiang (Yangtze) estuary by the Changjiang River promote the propagation of coastal wetlands, the...Coastal wetlands play an important role in the global carbon cycle. Large quantities of sediment deposited in the Changjiang (Yangtze) estuary by the Changjiang River promote the propagation of coastal wetlands, the expansion of saltmarsh vegetation, and carbon sequestration. In this study, using the Chongming Dongtan Wetland in the Changjiang estuary as the study area, the spatial and temporal distribution of soil organic carbon (SOC) stocks and the influences of sedimentation and vegetation on the SOC stocks of the coastal wetland were examined in 2013. There was sediment accretion in the northern and middle areas of the wetland and in the Phragmites australis marsh in the southern area, and sediment erosion in the Scirpus mariqueter marsh and the bare mudflat in the southem area. More SOC accumulated in sediments of the vegetated marsh than in the bare mudflat. The total organic carbon (TOC) stocks increased in the above-ground biomass from spring to autumn and decreased in winter; in the below-ground biomass, they gradually increased from spring to winter. The TOC stocks were higher in the below-ground biomass than in the above-ground biomass in the P. australis and Spartina alterniflora marshes, but were lower in the below-ground biomass in S. mariqueter marsh. Stocks of SOC showed temporal variation and increased gradually in all transects from spring to winter. The SOC stocks tended to decrease from the high marsh down to the bare mudflat along the three transects in the order: P. australis marsh 〉 S. alterniflora marsh 〉 S. mariqueter marsh 〉 bare mudflat. The SOC stocks of the same vegetation type were higher in the northern and middle transects than in the southern transect. These results suggest that interactions between sedimentation and vegetation regulate the SOC stocks in the coastal wetland in the Changjiang estuary.展开更多
Carbon monoxide (CO) intoxication is one of the most common types of poisoning in the modem world. To better tailor messages and communication needs to the public, a perception survey of CO and his risk was conducte...Carbon monoxide (CO) intoxication is one of the most common types of poisoning in the modem world. To better tailor messages and communication needs to the public, a perception survey of CO and his risk was conducted among the population of Rabat-Sale-Zemmour-Zaer. The authors included 400 people in this survey. The demographic characteristics of the respondents consisted of: 85.0% female, 92.9% adults, 29.7% had a high level of education, 49.6% unemployed, 89.5% were home owners and 53.9% lived in apartments. Water heaters were present in the homes of 91.0% of respondents and 6.5% of them used gas. Gas was used as fuel in 45.4% of cases. For water heaters, 20.8% had an exhaust duct, 9.9% were serviced regularly and 47.5% were installed in a well ventilated area. Regarding the media, television was the medium that allowed 73.4% of the CO to know, regardless of age, sex and level of education among the 94.3% of who ever heard of this deadly gas before the survey.展开更多
In this paper,using the input-output model,the author first calculated the CO 2 emissions embodied in exports of China in 2002 and 2007.Then,the author empirically analyzed problems existing in the composition of expo...In this paper,using the input-output model,the author first calculated the CO 2 emissions embodied in exports of China in 2002 and 2007.Then,the author empirically analyzed problems existing in the composition of exported products and analyzed its possible reasons.The research results of this paper are as follows:Since China's entry into WTO,the CO 2 emissions embodied in exports of China have been increasing rapidly;the value of exported products of high-carbon emissions industries accounts for a relatively higher proportion to China's total exports value because China's carbon intensive products have a certain competitive advantage.Additionally,this paper has put forward relevant suggestions based on these results.展开更多
Evidence from lithology, foraminiferal assemblages, and high-resolution X-ray fluorescence scanning data of core SFK-1 indicates tidally influenced paleo-fluvial sedimentation during the last glacial maximum (LGM) on ...Evidence from lithology, foraminiferal assemblages, and high-resolution X-ray fluorescence scanning data of core SFK-1 indicates tidally influenced paleo-fluvial sedimentation during the last glacial maximum (LGM) on the outer shelf of the East China Sea. The paleo-fluvial deposits consist of river channel facies and estuarine incised-valley-filling facies. Different reflections on the seismic profile across core SFK-1 suggest that the river channels shifted and overlapped. River channel deposition formed early in the LGM when sea level fell and the estuary extended to the outer shelf. Channel sediments are yellowish- brown in color and rich in foraminifera and shell fragments owing to the strong tidal influence. Following the LGM, the paleo-river mouth retreated and regressive deposition of estuarine and incised-valley-filling facies with an erosion base occurred. The river channel facies and estuarine incised-valley-filling facies have clearly different sedimentary characteristics and provenances. The depositional environment of the paleo-river system on the wide shelf was reconstructed from the foraminiferal assemblages, CaCO3 content and Ca/Ti ratio. The main results of this study provide further substantial constraints on the recognition of late Quaternary stratigraphy and land-sea interactions on the ECS shelf.展开更多
The EU, the United States and other economies, with the intention to implement unilateral trade measures Border Carbon Adjustments, impose emission reduction pressure on developing countries. Once implemented, the mea...The EU, the United States and other economies, with the intention to implement unilateral trade measures Border Carbon Adjustments, impose emission reduction pressure on developing countries. Once implemented, the measures will have great impact on China's foreign trade. Using the input-output table in 2007, this paper had analyzed the influences on China's foreign trade as a whole and sub-sectors in three tax rates scenarios. The results showed that the tariff level of China's exports will increase by 3.6%-6.3% if the tax was levied on exports embodied emissions, and by 1.0%-1.7% if levied on export direct emissions. In 2007, the former total amount of carbon tax was about US$42.6-73.0 billion, 4 times that of the latter. Based on export embodied emissions, sectors largely influenced were non-traditional energy intensive ones, such as textile, et al. These sectors should be encour-aged to carry out industrial upgrading, raising the value-added of export goods, and reducing their embodied emissions by reduction of energy intensity. Taking into account of the complexity of data collection, the tax levied on products direct emission is more operational. The results showed that the five top sectors most affected were other chemical materials, processing of petroleum and nuclear fuel, coking, smelting and rolling of ferrous metal and textile. Most of them were energy intensive sectors. Therefore, adjusting export products structure, and controlling too fast development of energy intensive industries are also important strategies in China.展开更多
This paper uses the Global Trade Analysis Project(version 7)database to calculate embodied CO2emissions in bilateral trade between China and other countries(regions)based on input-output methods.The sources and flows ...This paper uses the Global Trade Analysis Project(version 7)database to calculate embodied CO2emissions in bilateral trade between China and other countries(regions)based on input-output methods.The sources and flows of embodied CO2emissions in import and export trade of China are analyzed.Results show that the flows of embodied CO2emissions in export trade are highly concentrated.The main flows to the United States(US)and Japan account for 1/4 and 1/7 of the total CO2emissions in export trade,respectively.Concentrated flows of total exports and small differences in export structure are the main reasons for the highly concentrated export trade.The sources of embodied CO2emissions in import trade have relatively low concentration.Taiwan Province of China,Hong Kong Special Administrative Region of China,US,Russia,Republic of Korea,and Japan account for around 7.72%–12.67%of the total embodied CO2emissions in import trade.The relative dispersion of import sources,the impact of the import structure,and the level of production technology in importing countries caused low concentration of CO2emissions in import trade.Overall,the embodied CO2emissions in the export trade of China are higher than those in import trade.As a result,production-based CO2emissions are higher than consumption-based CO2emissions.The difference of 8.96×108t of CO2,which comes mainly from the US,Japan,Germany,and the United Kingdom,accounts for 58.70%of the total difference.Some suggestions,such as improving energy efficiency,alerting high carbon-intensive industries transfer,expanding the market for sharing risks,and prompting the accounting system of consumption-based CO2emissions,are proposed based on the results.展开更多
The structural and dynamical properties of hexafluoroacetylacetone(HFA) and acetylacetone(AA) at the water/supercritical CO2(Sc-CO2) interface at 20 MPa and 318.15 K are investigated by molecular dynamics simulations....The structural and dynamical properties of hexafluoroacetylacetone(HFA) and acetylacetone(AA) at the water/supercritical CO2(Sc-CO2) interface at 20 MPa and 318.15 K are investigated by molecular dynamics simulations.The TIP3P potential is used for water and the EPM2 model is for CO2.The water phase and SC-CO2 phase form a distinct immiscible liquid-liquid interface.The two chelating molecules show interfacial preference.Comparatively,the AA molecules show somewhat more preference for interfacial region,whereas the HFA molecules are preferably near the Sc-CO2 phase.The orientational distribution of the β-diketone molecules and the radial distribution functions between β-diketones and solvents are obtained in order to study the microscopic structural properties of the β-diketones at the water-SC-CO2 interface.It is found that the translational diffusion and rotational diffusion of HFA and AA are obviously anisotropic and decrease as the β-diketone molecules approach the interface.The anisotropic dynamic behavior for the solute molecules is related to the corresponding structural properties.展开更多
Carbon fiber composites have high strength, high stiffness and light weight characteristics to apply to many fields, such as leisure, energy and transportation industries. The CFRP (carbon fiber reinforced polymers/p...Carbon fiber composites have high strength, high stiffness and light weight characteristics to apply to many fields, such as leisure, energy and transportation industries. The CFRP (carbon fiber reinforced polymers/plastics) composites made of carbon fibers as reinforcement and epoxy resins as matrix were prepared by drum winding process. Various parameters such as molding temperature, molding pressure and pressing time were selected as the pre-pregs were laminated to be the CFRP. The effects of fabricating parameters which affected the mechanical properties of CFRPs were analyzed by Taguchi method in this study. The results showed that molding temperature was the main factor to influence the mechanical properties of composites.展开更多
Taguchi method, largely used to optimize processes controlled by manifold parameters, has been utilized to improve the synthesis of carbon nanotubes by chemical vapor deposition of isobutane. Analyzing results obtaine...Taguchi method, largely used to optimize processes controlled by manifold parameters, has been utilized to improve the synthesis of carbon nanotubes by chemical vapor deposition of isobutane. Analyzing results obtained in nine suitably designed reactions, the influence of synthesis (773-973 K), calcinations (723-1,023 K) and reduction (773-973 K) temperatures and catalyst-support (alumina, magnesia or Na+-exchanged K10 clay) on specific yield and crystallization degree (i.e., C sp2 content) of the nanotubes has been ranked. After critical examination and adjusting of conditions predicted to give optimal results, -50 g of nanotubes per gram of metal are obtained at 973 K over Fe/alumina catalysts calcined at 723 K and reduced at 773 K. Under the same conditions, highly crystallized nanotubes (with 73% of C sp2 bonds, as qualitatively estimated from Raman spectroscopy), suitable for electro-catalysis applications, are synthesized over Fe/clay catalysts.展开更多
Two kinds of unidirectional PAN M40 carbon fiber (55%, volume fraction) reinforced 6061Al and 5A06Al composites were fabricated by the squeeze-casting technology and their interface structure and thermal expansion p...Two kinds of unidirectional PAN M40 carbon fiber (55%, volume fraction) reinforced 6061Al and 5A06Al composites were fabricated by the squeeze-casting technology and their interface structure and thermal expansion properties were investigated. Results showed that the combination between aluminum alloy and fibers was well in two composites and interface reaction in M40/5A06Al composite was weaker than that in M40/6061Al composite. Coefficients of thermal expansion (CTE) of M40/Al composites varied approximately from (1.45-2.68)×10^-6 K^-1 to (0.35-1.44)×10^-6 K^-1 between 20℃ and 450℃, and decreased slowly with the increase of temperature. In addition, the CTE of M40/6061Al composite was lower than that of M40/SA06Al composite. It was observed that fibers were protruded significantly from the matrix after thermal expansion, which demonstrated the existence of interface sliding between fiber and matrix during the thermal expansion. It was believed that weak interracial reaction resulted in a higher CTE. It was found that the experimental CTEs were closer to the predicted values by Schapery model.展开更多
The turbidity maximum zone(TMZ) is one of the most important regions in an estuary.However,the high concentration of suspended material makes it difficult to measure the partial pressure of CO_2(pCO_2) in these region...The turbidity maximum zone(TMZ) is one of the most important regions in an estuary.However,the high concentration of suspended material makes it difficult to measure the partial pressure of CO_2(pCO_2) in these regions.Therefore,very little data is available on the pCO_2 levels in TMZs.To relatively accurately evaluate the CO_2 flux in an example estuary,we studied the TMZ and surrounding area in the Changjiang(Yangtze) River estuary.From seasonal cruises during February,August,November 2010,and May 2012,the pCO_2 in the TMZ and surrounding area was calculated from pH and total alkalinity(TA)measured in situ,from which the CO_2 flux was calculated.Overall,the TMZ and surrounding area acted as a source of atmosphere CO_2 in February and November,and as a sink in May and August.The average FCO_2was-9,-16,5,and 5 mmol/(m^2·d) in May,August,November,and February,respectively.The TMZ's role as a source or sink of atmosphere CO_2 was quite different to the outer estuary.In the TMZ and surrounding area,suspended matter,phytoplankton,and pH were the main factors controlling the FCO_2,but here the influence of temperature,salinity,and total alkalinity on the FCO_2 was weak.Organic carbon decomposition in suspended matter was the main reason for the region acting as a CO_2 source in winter,and phytoplankton production was the main reason the region was a CO_2 sink in summer.展开更多
Eutrophication and climate change, key environmental concerns, are both linked to the carbon and nitrogen cycles hence the improved understanding of these cycles is essential. Currently, there is no system that simult...Eutrophication and climate change, key environmental concerns, are both linked to the carbon and nitrogen cycles hence the improved understanding of these cycles is essential. Currently, there is no system that simultaneously measures the fluxes of the three key gas phase products of nitrogen and carbon cycling (CO2, CH4 and N2O) in submerged ecosystems with hourly time resolution. A "Lake-in-a-box" (mesocosm) was developed in the laboratory which allowed the monitoring of key components of the carbon and nitrogen cycles within the air, water and sediments. The approach is automated, simple and time efficient and novel in its ability to examine many different carbon and nitrogen compounds in all three physical component of the "lake". Dramatic fluctuations in gaseous flux and the concentrations of overlying water and sedimentary carbon and nitrogen compounds were noted over a three week period. These were split into five distinct phases which were linked to changes in sedimentary N and C cycling. The results highlighted the important of links between the two cycles and supported recent studies showing that estuarine sediments can act as both a source and a sink of nitrogen.展开更多
The lifetime of roll-bits with inserted tooth will be obviously decreased while drilling in strata and the tungsten carbide can be integrally separated from the roll-cone,which will need more trip out time to replace ...The lifetime of roll-bits with inserted tooth will be obviously decreased while drilling in strata and the tungsten carbide can be integrally separated from the roll-cone,which will need more trip out time to replace the roller bit.This study provides an entire analysis on stress as well as strength for teeth and tooth holes in loaded conditions.Qualities of tooth drop from matrix within roller bit.The optimized interferences of teeth inserted into the bit can be reasonably obtained by the critical interference derived from some relevant influence factors on the tooth-fixing quality of roller bits.展开更多
Nutritional factors influence regulation of growth hormone (GH), insulin-like growth factor-Ⅰ (IGF-Ⅰ) and insulin (INS) in fish. But so far there are no published studies describing how single indispensable am...Nutritional factors influence regulation of growth hormone (GH), insulin-like growth factor-Ⅰ (IGF-Ⅰ) and insulin (INS) in fish. But so far there are no published studies describing how single indispensable amino acids and different carbohydrate to lipid ratios influence those systems. Therefore, the present study aimed to evaluate whether arginine (Arg) intake and carbohydrate to lipid ratios would affect expression of GH, IGF-Ⅰ and INS in largemouth bass.展开更多
文摘As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural antioxidant, which has undisputable protectiveaction against free radical damages. In order to ascertain whether their combination could affordbetter effect, we have investigated the prophylactic effect of the couplant ascorbate-lysine inliver injuries.
基金supported by the National Basic Research Program of China (No. 2002CB412504)
文摘Riverine carbon flux is an important component of the global carbon cycle. The spatial and temporal variations of organic and inorganic carbon were examined during both dry and wet seasons in the Yellow River estuary. Concentrations of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in the Yellow River during dry seasons were higher than those during wet seasons. The effective concentrations of DOC (CDOC*) were higher than the observed DOC at zero salinity. This input of DOC in the Yellow River estuary was due to sediment desorption processes in low salinity regions. In contrast to DOC, the effective concen- trations of DIC were 10% lower than the DIC measured at freshwater end, and the loss of DIC was caused by CaCO3 precipitation in low salinity region, Particulate organic carbon (POC) and particulate inorganic carbon (PIC) contents of the particles stabilized to constant values (0.5%:t:0.05% and 1.8%--0.2%, respectively) within the turbidity maximum zone (TMZ) and showed no noticeable seasonal variations. A rapid drop of PIC and rise of POC occurred simultaneously outside the TMZ due to an intense dilution of riv- erine inorganic-rich particles being transported into a pool of aquatic organic-poor particles outside the TMZ. Annually, the Yellow River transported 6.95× 10^5 t of DIC, 0.64× 10^5 t of DOC, 78.58× 10^5 t of PIC and 2.29× 10^5 t of POC to the sea.
基金supported by the National Basic Research Program of China(973 program,No.2010CB428903)Public Science and Technology Research Funds the Projects of Ocean(No.201105014)+1 种基金National Natural Science Foundation of China(No.41203085)the Fundamental Research Funds for the Second Institute of Oceanography,SOA(JT0906)
文摘The eutrophication, hypoxia and coastal acidification are attracting more and more attention. In this study, inorganic carbon parameters, including dissolved inorganic carbon (DIC), total alkalinity (TA) and calculated partial pressure of CO2 (pCO2), obtained from a summer cruise in August, 2009, were used to investigate their integrated response to biological processes accompanying the oxygen depletion in the areas off the Changjiang Estuary. According to the observations, the typical hypoxia occurred in the bottom water just outside the Changjiang Estuary with Dissolved Oxygen (DO) lower than 2.00 mg L^-1. The biological uptake in the surface water and the decomposition of organic matter in the bottom water were fully coupled with each other. The high concentration of Chl_a (Chl_a = 10.9μgL^-1) and DO (9.25 mgL^-1), profoundly decreased DIC concentration 0828 μmolkg^-1) and elevated pH (8.42) was observed in the surface water. The correspondingly increased DIC and depletion of oxygen were observed in the bottom water. The semi-quantitative analysis proved that the locally-produced phytoplankton, determined by primary productivity, was deposited to the bottom and contributed about 76% of total amount of the organic carbon decomposition in the bottom. However, in the bottom hypoxia (DO = 2.05 mgL^-1) area observed in the Southern Zhejiang coastal water, the responding patterns of inorganic carbon parameters deviated from the previous one. The expanding of Changjiang Diluted Water (CDW), the adding of Hangzhou Bay water (with high DIC concentration) and Coastal Current together modify the DIC background value in this area, and the local degeneration and upwelling process may also help to offset the local DIC removed by net biological uptake in surface water. In addition when the mixing occurring in autumn, which may break the summer stratification, the excess release of high DIC in the bottom water to the subsurface water could have an important influence on coastal acidification and the CO2 uptake capacity in this area.
基金Project(20803095)supported by the National Natural Science Foundation of ChinaProject(2008AA03Z207)supported by the National High Technology Research and Development Program of China
文摘The activated carbon wound supercapacitors with TEABF4/propylene carbonate (PC) and TEABF4/acetonitrile (AN) electrolytes were prepared. The effects of the electrolyte and temperature on the capacitance behavior were investigated by cyclic voltammetry (CV) and constant current charge-discharge. Compared with the PC-based supercapacitor, the AN-based supercapacitor has higher capacitance and lower equivalent serial resistance (RES) at discharge currents ranging from 5 to 1 000 mA and 25 ℃. Moreover, temperature effects are more prominent for PC-based supercapacitor than for AN-based supereapacitor. When the measurement temperature ranges from 60 ℃to -40 ℃ the capacitance changes from 5.1 to 2.5 F and RES changes from 135 to 876 mΩ for the PC-based supercapacior, while the AN-based supercapacitor shows less change in capacitance and RES. Thus AN-based supercapacitor exhibits excellent power characteristics and temperature property.
基金Supported by the Marine Science Project of Shanghai Committee of Science and Technology,China(No.14DZ1206004)the National Natural Science Foundation of China(No.41571083)the autonomous research fund of the State Key Laboratory of Estuarine and Coastal Research,China(No.2015KYYW03)
文摘Coastal wetlands play an important role in the global carbon cycle. Large quantities of sediment deposited in the Changjiang (Yangtze) estuary by the Changjiang River promote the propagation of coastal wetlands, the expansion of saltmarsh vegetation, and carbon sequestration. In this study, using the Chongming Dongtan Wetland in the Changjiang estuary as the study area, the spatial and temporal distribution of soil organic carbon (SOC) stocks and the influences of sedimentation and vegetation on the SOC stocks of the coastal wetland were examined in 2013. There was sediment accretion in the northern and middle areas of the wetland and in the Phragmites australis marsh in the southern area, and sediment erosion in the Scirpus mariqueter marsh and the bare mudflat in the southem area. More SOC accumulated in sediments of the vegetated marsh than in the bare mudflat. The total organic carbon (TOC) stocks increased in the above-ground biomass from spring to autumn and decreased in winter; in the below-ground biomass, they gradually increased from spring to winter. The TOC stocks were higher in the below-ground biomass than in the above-ground biomass in the P. australis and Spartina alterniflora marshes, but were lower in the below-ground biomass in S. mariqueter marsh. Stocks of SOC showed temporal variation and increased gradually in all transects from spring to winter. The SOC stocks tended to decrease from the high marsh down to the bare mudflat along the three transects in the order: P. australis marsh 〉 S. alterniflora marsh 〉 S. mariqueter marsh 〉 bare mudflat. The SOC stocks of the same vegetation type were higher in the northern and middle transects than in the southern transect. These results suggest that interactions between sedimentation and vegetation regulate the SOC stocks in the coastal wetland in the Changjiang estuary.
文摘Carbon monoxide (CO) intoxication is one of the most common types of poisoning in the modem world. To better tailor messages and communication needs to the public, a perception survey of CO and his risk was conducted among the population of Rabat-Sale-Zemmour-Zaer. The authors included 400 people in this survey. The demographic characteristics of the respondents consisted of: 85.0% female, 92.9% adults, 29.7% had a high level of education, 49.6% unemployed, 89.5% were home owners and 53.9% lived in apartments. Water heaters were present in the homes of 91.0% of respondents and 6.5% of them used gas. Gas was used as fuel in 45.4% of cases. For water heaters, 20.8% had an exhaust duct, 9.9% were serviced regularly and 47.5% were installed in a well ventilated area. Regarding the media, television was the medium that allowed 73.4% of the CO to know, regardless of age, sex and level of education among the 94.3% of who ever heard of this deadly gas before the survey.
基金funded by 2011 the Humanities and Social Sciences Research Program of Education Ministry of P.R.China (Grant No.11YJA790229)
文摘In this paper,using the input-output model,the author first calculated the CO 2 emissions embodied in exports of China in 2002 and 2007.Then,the author empirically analyzed problems existing in the composition of exported products and analyzed its possible reasons.The research results of this paper are as follows:Since China's entry into WTO,the CO 2 emissions embodied in exports of China have been increasing rapidly;the value of exported products of high-carbon emissions industries accounts for a relatively higher proportion to China's total exports value because China's carbon intensive products have a certain competitive advantage.Additionally,this paper has put forward relevant suggestions based on these results.
基金Supported by the National Natural Science Foundation of China (Nos.41040041,41206053,41225020,and 41076018) the Continental Shelf Drilling Program (No.GZH201100202)the China Geological Survey(Nos.1212010611301 and GZH200800501)
文摘Evidence from lithology, foraminiferal assemblages, and high-resolution X-ray fluorescence scanning data of core SFK-1 indicates tidally influenced paleo-fluvial sedimentation during the last glacial maximum (LGM) on the outer shelf of the East China Sea. The paleo-fluvial deposits consist of river channel facies and estuarine incised-valley-filling facies. Different reflections on the seismic profile across core SFK-1 suggest that the river channels shifted and overlapped. River channel deposition formed early in the LGM when sea level fell and the estuary extended to the outer shelf. Channel sediments are yellowish- brown in color and rich in foraminifera and shell fragments owing to the strong tidal influence. Following the LGM, the paleo-river mouth retreated and regressive deposition of estuarine and incised-valley-filling facies with an erosion base occurred. The river channel facies and estuarine incised-valley-filling facies have clearly different sedimentary characteristics and provenances. The depositional environment of the paleo-river system on the wide shelf was reconstructed from the foraminiferal assemblages, CaCO3 content and Ca/Ti ratio. The main results of this study provide further substantial constraints on the recognition of late Quaternary stratigraphy and land-sea interactions on the ECS shelf.
文摘The EU, the United States and other economies, with the intention to implement unilateral trade measures Border Carbon Adjustments, impose emission reduction pressure on developing countries. Once implemented, the measures will have great impact on China's foreign trade. Using the input-output table in 2007, this paper had analyzed the influences on China's foreign trade as a whole and sub-sectors in three tax rates scenarios. The results showed that the tariff level of China's exports will increase by 3.6%-6.3% if the tax was levied on exports embodied emissions, and by 1.0%-1.7% if levied on export direct emissions. In 2007, the former total amount of carbon tax was about US$42.6-73.0 billion, 4 times that of the latter. Based on export embodied emissions, sectors largely influenced were non-traditional energy intensive ones, such as textile, et al. These sectors should be encour-aged to carry out industrial upgrading, raising the value-added of export goods, and reducing their embodied emissions by reduction of energy intensity. Taking into account of the complexity of data collection, the tax levied on products direct emission is more operational. The results showed that the five top sectors most affected were other chemical materials, processing of petroleum and nuclear fuel, coking, smelting and rolling of ferrous metal and textile. Most of them were energy intensive sectors. Therefore, adjusting export products structure, and controlling too fast development of energy intensive industries are also important strategies in China.
基金Under the auspices of National Natural Science Foundation of China(No.40905062,71103012)National Basic Research Program of China(No.2012CB955904)
文摘This paper uses the Global Trade Analysis Project(version 7)database to calculate embodied CO2emissions in bilateral trade between China and other countries(regions)based on input-output methods.The sources and flows of embodied CO2emissions in import and export trade of China are analyzed.Results show that the flows of embodied CO2emissions in export trade are highly concentrated.The main flows to the United States(US)and Japan account for 1/4 and 1/7 of the total CO2emissions in export trade,respectively.Concentrated flows of total exports and small differences in export structure are the main reasons for the highly concentrated export trade.The sources of embodied CO2emissions in import trade have relatively low concentration.Taiwan Province of China,Hong Kong Special Administrative Region of China,US,Russia,Republic of Korea,and Japan account for around 7.72%–12.67%of the total embodied CO2emissions in import trade.The relative dispersion of import sources,the impact of the import structure,and the level of production technology in importing countries caused low concentration of CO2emissions in import trade.Overall,the embodied CO2emissions in the export trade of China are higher than those in import trade.As a result,production-based CO2emissions are higher than consumption-based CO2emissions.The difference of 8.96×108t of CO2,which comes mainly from the US,Japan,Germany,and the United Kingdom,accounts for 58.70%of the total difference.Some suggestions,such as improving energy efficiency,alerting high carbon-intensive industries transfer,expanding the market for sharing risks,and prompting the accounting system of consumption-based CO2emissions,are proposed based on the results.
基金Supported by the National Natural Science Foundation of China (20776066, 20476044) and the Specialized Research Fund for the Doctoral Program of Higher Education of China (20060291002).
文摘The structural and dynamical properties of hexafluoroacetylacetone(HFA) and acetylacetone(AA) at the water/supercritical CO2(Sc-CO2) interface at 20 MPa and 318.15 K are investigated by molecular dynamics simulations.The TIP3P potential is used for water and the EPM2 model is for CO2.The water phase and SC-CO2 phase form a distinct immiscible liquid-liquid interface.The two chelating molecules show interfacial preference.Comparatively,the AA molecules show somewhat more preference for interfacial region,whereas the HFA molecules are preferably near the Sc-CO2 phase.The orientational distribution of the β-diketone molecules and the radial distribution functions between β-diketones and solvents are obtained in order to study the microscopic structural properties of the β-diketones at the water-SC-CO2 interface.It is found that the translational diffusion and rotational diffusion of HFA and AA are obviously anisotropic and decrease as the β-diketone molecules approach the interface.The anisotropic dynamic behavior for the solute molecules is related to the corresponding structural properties.
文摘Carbon fiber composites have high strength, high stiffness and light weight characteristics to apply to many fields, such as leisure, energy and transportation industries. The CFRP (carbon fiber reinforced polymers/plastics) composites made of carbon fibers as reinforcement and epoxy resins as matrix were prepared by drum winding process. Various parameters such as molding temperature, molding pressure and pressing time were selected as the pre-pregs were laminated to be the CFRP. The effects of fabricating parameters which affected the mechanical properties of CFRPs were analyzed by Taguchi method in this study. The results showed that molding temperature was the main factor to influence the mechanical properties of composites.
文摘Taguchi method, largely used to optimize processes controlled by manifold parameters, has been utilized to improve the synthesis of carbon nanotubes by chemical vapor deposition of isobutane. Analyzing results obtained in nine suitably designed reactions, the influence of synthesis (773-973 K), calcinations (723-1,023 K) and reduction (773-973 K) temperatures and catalyst-support (alumina, magnesia or Na+-exchanged K10 clay) on specific yield and crystallization degree (i.e., C sp2 content) of the nanotubes has been ranked. After critical examination and adjusting of conditions predicted to give optimal results, -50 g of nanotubes per gram of metal are obtained at 973 K over Fe/alumina catalysts calcined at 723 K and reduced at 773 K. Under the same conditions, highly crystallized nanotubes (with 73% of C sp2 bonds, as qualitatively estimated from Raman spectroscopy), suitable for electro-catalysis applications, are synthesized over Fe/clay catalysts.
基金Project(DL09BB23) supported by the Fundamental Research Funds for the Central Universities in China
文摘Two kinds of unidirectional PAN M40 carbon fiber (55%, volume fraction) reinforced 6061Al and 5A06Al composites were fabricated by the squeeze-casting technology and their interface structure and thermal expansion properties were investigated. Results showed that the combination between aluminum alloy and fibers was well in two composites and interface reaction in M40/5A06Al composite was weaker than that in M40/6061Al composite. Coefficients of thermal expansion (CTE) of M40/Al composites varied approximately from (1.45-2.68)×10^-6 K^-1 to (0.35-1.44)×10^-6 K^-1 between 20℃ and 450℃, and decreased slowly with the increase of temperature. In addition, the CTE of M40/6061Al composite was lower than that of M40/SA06Al composite. It was observed that fibers were protruded significantly from the matrix after thermal expansion, which demonstrated the existence of interface sliding between fiber and matrix during the thermal expansion. It was believed that weak interracial reaction resulted in a higher CTE. It was found that the experimental CTEs were closer to the predicted values by Schapery model.
基金Supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05030402)the National Natural Science Foundation of China(Nos.U1406403,41121064,41376092)the Public Science and Technology Research Funds Projects of Ocean(No.200905012-9)
文摘The turbidity maximum zone(TMZ) is one of the most important regions in an estuary.However,the high concentration of suspended material makes it difficult to measure the partial pressure of CO_2(pCO_2) in these regions.Therefore,very little data is available on the pCO_2 levels in TMZs.To relatively accurately evaluate the CO_2 flux in an example estuary,we studied the TMZ and surrounding area in the Changjiang(Yangtze) River estuary.From seasonal cruises during February,August,November 2010,and May 2012,the pCO_2 in the TMZ and surrounding area was calculated from pH and total alkalinity(TA)measured in situ,from which the CO_2 flux was calculated.Overall,the TMZ and surrounding area acted as a source of atmosphere CO_2 in February and November,and as a sink in May and August.The average FCO_2was-9,-16,5,and 5 mmol/(m^2·d) in May,August,November,and February,respectively.The TMZ's role as a source or sink of atmosphere CO_2 was quite different to the outer estuary.In the TMZ and surrounding area,suspended matter,phytoplankton,and pH were the main factors controlling the FCO_2,but here the influence of temperature,salinity,and total alkalinity on the FCO_2 was weak.Organic carbon decomposition in suspended matter was the main reason for the region acting as a CO_2 source in winter,and phytoplankton production was the main reason the region was a CO_2 sink in summer.
文摘Eutrophication and climate change, key environmental concerns, are both linked to the carbon and nitrogen cycles hence the improved understanding of these cycles is essential. Currently, there is no system that simultaneously measures the fluxes of the three key gas phase products of nitrogen and carbon cycling (CO2, CH4 and N2O) in submerged ecosystems with hourly time resolution. A "Lake-in-a-box" (mesocosm) was developed in the laboratory which allowed the monitoring of key components of the carbon and nitrogen cycles within the air, water and sediments. The approach is automated, simple and time efficient and novel in its ability to examine many different carbon and nitrogen compounds in all three physical component of the "lake". Dramatic fluctuations in gaseous flux and the concentrations of overlying water and sedimentary carbon and nitrogen compounds were noted over a three week period. These were split into five distinct phases which were linked to changes in sedimentary N and C cycling. The results highlighted the important of links between the two cycles and supported recent studies showing that estuarine sediments can act as both a source and a sink of nitrogen.
文摘The lifetime of roll-bits with inserted tooth will be obviously decreased while drilling in strata and the tungsten carbide can be integrally separated from the roll-cone,which will need more trip out time to replace the roller bit.This study provides an entire analysis on stress as well as strength for teeth and tooth holes in loaded conditions.Qualities of tooth drop from matrix within roller bit.The optimized interferences of teeth inserted into the bit can be reasonably obtained by the critical interference derived from some relevant influence factors on the tooth-fixing quality of roller bits.
文摘Nutritional factors influence regulation of growth hormone (GH), insulin-like growth factor-Ⅰ (IGF-Ⅰ) and insulin (INS) in fish. But so far there are no published studies describing how single indispensable amino acids and different carbohydrate to lipid ratios influence those systems. Therefore, the present study aimed to evaluate whether arginine (Arg) intake and carbohydrate to lipid ratios would affect expression of GH, IGF-Ⅰ and INS in largemouth bass.