The coastal shelter forest in China is under threat of destruction and degradation because of the impact of human activities. Protection efficiency assessment of the coastal shelterbelt is an important component of sh...The coastal shelter forest in China is under threat of destruction and degradation because of the impact of human activities. Protection efficiency assessment of the coastal shelterbelt is an important component of shelterforest remediation planning and sustainable management. In this study, a protection efficiency index (PEI) model was established using the projection pursuit method to assess the protective quality of the coastal shelter forest at the coastal section scale of Dongshan Island, China. Three criteria were used, including forest stand structure, forest belt structure, and windbreak effect; each criterion further comprised multiple factors. Based on survey data of 31 plots in the coastal shelter forest of Dongshan Island, we calculated PEI values using a projection of a pursuit model. The result showed 64.5 % of the PEIs fell at or below the middle level, which can indicate the status of the coastal shelterbelt is unsatisfactory. To further explore whether the different bays and land use types create significant differences in PEIs and evaluation indices, we used an ANOVA to test the influence of various bays and forms of land use on coastal shelterbelts. The results showed that PEI and most of the indices differed significantly by bay; mean tree height, mean DBH, mean crown width, stand density, vegetation coverage, and wind velocity reduction differed significantly by land use. Therefore, relevant measures for different locations, bays and surrounding land use can be proposed to improve the existing conditions of the coastal shelterbelt. The results of this study provide a theoretical and technical framework for future changes and sustainable management of coastal shelterbelt on Dongshan Island.展开更多
In this paper, the effects of zinc (Zn) and magnesium (Mg) addition on the performance of an aluminum-based sacrificial anode in seawater were investigated using a potential measurement method. Anodic efficiency, ...In this paper, the effects of zinc (Zn) and magnesium (Mg) addition on the performance of an aluminum-based sacrificial anode in seawater were investigated using a potential measurement method. Anodic efficiency, protection efficiency, and polarized potential were the parameters used. The percentages of Zn and Mg in the anodes were varied from 2% to 8% Zn and 1% to 4% Mg. The alloys produced were tested as sacrificial anodes for the protection of mild steel in seawater at room temperature. Current efficiency as high as 88.36% was obtained in alloys containing 6% Zn and 1% Mg. The polarization potentials obtained for the coupled (steel/Al-based alloys) are as given in the Pourbaix diagrams, with steel lying within the immunity region/cathodic region and the sacrificial anodes within the anodic region. The protection offered by the sacrificial anodes to the steel after the 7th and 8th week was measured and protection efficiency values as high as 99.66% and 99.47% were achieved for the A1-6%Zn-l%Mg cast anode. The microstructures of the cast anodes comprise of intermetallic structures of hexagonal Mg3Zn2 and body-centered cubic A12Mg3Zn3. These are probably responsible for the breakdown of the passive alumina film, thus enhancing the anode efficiency.展开更多
The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(B...The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(BKPFs) are shrinking quickly due to deforestation and rapid urbanization. Thus, scientific protection strategies are urgently needed to change this status. Changbai Mountains contains one of the largest BKPFs and is considered a priority biodiversity conservation area in China. Guided by systematic conservation planning(SCP) methods and procedures, we chose representative species and communities in BKPFs ecosystem as priority conservation objects, and set quantitative conservation target, which is in the light of the biodiversity characteristic of BKPFs. The watershed area is used as planning unit. We used CPlan software to calculate the irreplaceability(Ir)value of each planning unit and the contribution value(Ti) of each conservation object to(1) assess the conservation efficiency;(2) identify the conservation gap of the existing conservation network. Then wecalculated a human disturbance index(HDI) for planning units in the conservation gaps and combine this with the Ir value to design three conservation scenarios to optimize the conservation network.Results show that planning units with high conservation value 14.16% of the total area, with3084.36 km2 were covered by the existing conservation network. 79.28% of planning units with high conservation value have not been protected which were concentrated mainly in the eight gap areas.Only 25.3% of protection objects achieved their conservation target with the existing conservation network. Conservation efficiency is low. Three conservation scenarios are constituted, each prioritizing a different aim:(1) ecological value;(2)species rescue; and(3) economical avoidance. The three conservation schemes potentially enable 93%,88% and 51% of conservation objects, respectively, to achieve identified conservation targets, thereby improving conservation efficiency significantly.展开更多
Polymeric nanofibers are a promising technology to protect the metal surfaces from corrosion.Through the literature search,the use of polyacrylonitrile nanofibres(PANNFs)as a corrosion inhibitor coating for aluminum a...Polymeric nanofibers are a promising technology to protect the metal surfaces from corrosion.Through the literature search,the use of polyacrylonitrile nanofibres(PANNFs)as a corrosion inhibitor coating for aluminum alloys has not been evaluated.This work includes the development of a new,lightweight,high surface area and efficient coating of PANNFs that produced using electrospinning process to resist the corrosion of aluminum alloys(AA5083)which immersed in 0.6 M NaCl at alkaline medium(pH=12)and acidic medium(pH=1)at a range of temperatures(293–323)K.The PANNFs coating was successfully deposited on AA 5083 specimens,where these samples were considered as a collector electrode in the electrospinning process.The corrosion experiments of the aluminum alloys coated with PANNFs before and after immersion in both corrosive mediums were investigated using cyclic potential polarization(CPP).The results confirmed that the PANNFs coating was able to protect the surface of the aluminum specimens from corrosion,by reducing the corrosion current and increasing the surface polarization resistance,thus reducing the corrosion rate.The protection efficiency was found in the alkaline medium 98.8%while in the acidic medium 83.3%.So,it was in both mediums decreased with the increase in temperature.The shape,distribution and size of the polymeric nanofibers that formed the coating were also examined using field emission scanning electron microscopy(FE-SEM)and the percentages of the structural components of these fibers were detected using the X-ray dispersion spectroscopy(EDS).The surface of aluminum specimens was completely covered by PANNFs.These electrospun nanofibers have worn out and lined up spacing after immersion in the corrosive mediums.The diameters average of PANNFs was found to be about 200 and 150 nm before and after immersion,respectively.展开更多
The hottest topic now among Europe's automotive industry is CO2. The European Union has set the goal. By 2012, all Europe-based car makers would have to reduce the per car CO2 level to as low as 120-130g/km from t...The hottest topic now among Europe's automotive industry is CO2. The European Union has set the goal. By 2012, all Europe-based car makers would have to reduce the per car CO2 level to as low as 120-130g/km from the current 160g/km.展开更多
The flagship species conservation strategy is widely practiced in nature reserves.However,few studies have quantitatively explored whether the current functional zoning adequately conserves the habitats of other speci...The flagship species conservation strategy is widely practiced in nature reserves.However,few studies have quantitatively explored whether the current functional zoning adequately conserves the habitats of other species.To examine this problem,we selected the Tangjiahe,Xuebaoding,and Wanglang national nature reserves in southwest China and tested the protective efficiency of the giant panda(Ailuropoda melanoleuca)reserves on a local herbivore—Sichuan takin(Budorcas taxicolor tibetana)in functional zoning.We predicted that the habitat distribution of the Sichuan takin with Maxent and habitat suitability would be classified as very low,low,moderately,or highly suitable.We calculated the percentage of each type of habitat class across the core,buffer,and experimental zones in these reserves and introduced an economic index present value index to further assess the efficacy of the functional zoning in conserving the habitat of Sichuan takin.Our findings indicate that suitable habitat distributions of Sichuan takin are multicore and influenced by diverse variables in different nature reserves.The percentage of moderately suitable and highly suitable habitat in the core zone is 69%and 54%in Tangjiahe,76%and 75%in Wanglang,and 47%and 28%in Xuebaoding,respectively.The present value index of moderately and highly suitable habitat is 1.01 and 0.79(Tangjiahe),0.87 and 0.86(Wanglang),0.76 and 0.44(Xuebaoding),respectively.The efficiency of functional zoning on Sichuan takin seems lower than imagined in giant panda reserves,and species that have important impacts on local ecosystem need further estimation and greater focus.展开更多
Green manufacturing is a new way out for the auto industry—ZHAO Hang, president of CATARC The green manufacturing means a lot, in terms of the manufacturing process, material and techniques. China spares no efforts t...Green manufacturing is a new way out for the auto industry—ZHAO Hang, president of CATARC The green manufacturing means a lot, in terms of the manufacturing process, material and techniques. China spares no efforts to producing vehicles and it展开更多
基金supported by the National Natural Science Foundation of China(Nos.31200365,31370624,and30870435)the Youth Science Fund of the Forestry College of Fujian Agriculture and Forestry University(No.6112C039V)
文摘The coastal shelter forest in China is under threat of destruction and degradation because of the impact of human activities. Protection efficiency assessment of the coastal shelterbelt is an important component of shelterforest remediation planning and sustainable management. In this study, a protection efficiency index (PEI) model was established using the projection pursuit method to assess the protective quality of the coastal shelter forest at the coastal section scale of Dongshan Island, China. Three criteria were used, including forest stand structure, forest belt structure, and windbreak effect; each criterion further comprised multiple factors. Based on survey data of 31 plots in the coastal shelter forest of Dongshan Island, we calculated PEI values using a projection of a pursuit model. The result showed 64.5 % of the PEIs fell at or below the middle level, which can indicate the status of the coastal shelterbelt is unsatisfactory. To further explore whether the different bays and land use types create significant differences in PEIs and evaluation indices, we used an ANOVA to test the influence of various bays and forms of land use on coastal shelterbelts. The results showed that PEI and most of the indices differed significantly by bay; mean tree height, mean DBH, mean crown width, stand density, vegetation coverage, and wind velocity reduction differed significantly by land use. Therefore, relevant measures for different locations, bays and surrounding land use can be proposed to improve the existing conditions of the coastal shelterbelt. The results of this study provide a theoretical and technical framework for future changes and sustainable management of coastal shelterbelt on Dongshan Island.
文摘In this paper, the effects of zinc (Zn) and magnesium (Mg) addition on the performance of an aluminum-based sacrificial anode in seawater were investigated using a potential measurement method. Anodic efficiency, protection efficiency, and polarized potential were the parameters used. The percentages of Zn and Mg in the anodes were varied from 2% to 8% Zn and 1% to 4% Mg. The alloys produced were tested as sacrificial anodes for the protection of mild steel in seawater at room temperature. Current efficiency as high as 88.36% was obtained in alloys containing 6% Zn and 1% Mg. The polarization potentials obtained for the coupled (steel/Al-based alloys) are as given in the Pourbaix diagrams, with steel lying within the immunity region/cathodic region and the sacrificial anodes within the anodic region. The protection offered by the sacrificial anodes to the steel after the 7th and 8th week was measured and protection efficiency values as high as 99.66% and 99.47% were achieved for the A1-6%Zn-l%Mg cast anode. The microstructures of the cast anodes comprise of intermetallic structures of hexagonal Mg3Zn2 and body-centered cubic A12Mg3Zn3. These are probably responsible for the breakdown of the passive alumina film, thus enhancing the anode efficiency.
基金supported by the 12th fiveyear National Science and Technology plan of China (2012BAC01B03)
文摘The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(BKPFs) are shrinking quickly due to deforestation and rapid urbanization. Thus, scientific protection strategies are urgently needed to change this status. Changbai Mountains contains one of the largest BKPFs and is considered a priority biodiversity conservation area in China. Guided by systematic conservation planning(SCP) methods and procedures, we chose representative species and communities in BKPFs ecosystem as priority conservation objects, and set quantitative conservation target, which is in the light of the biodiversity characteristic of BKPFs. The watershed area is used as planning unit. We used CPlan software to calculate the irreplaceability(Ir)value of each planning unit and the contribution value(Ti) of each conservation object to(1) assess the conservation efficiency;(2) identify the conservation gap of the existing conservation network. Then wecalculated a human disturbance index(HDI) for planning units in the conservation gaps and combine this with the Ir value to design three conservation scenarios to optimize the conservation network.Results show that planning units with high conservation value 14.16% of the total area, with3084.36 km2 were covered by the existing conservation network. 79.28% of planning units with high conservation value have not been protected which were concentrated mainly in the eight gap areas.Only 25.3% of protection objects achieved their conservation target with the existing conservation network. Conservation efficiency is low. Three conservation scenarios are constituted, each prioritizing a different aim:(1) ecological value;(2)species rescue; and(3) economical avoidance. The three conservation schemes potentially enable 93%,88% and 51% of conservation objects, respectively, to achieve identified conservation targets, thereby improving conservation efficiency significantly.
文摘Polymeric nanofibers are a promising technology to protect the metal surfaces from corrosion.Through the literature search,the use of polyacrylonitrile nanofibres(PANNFs)as a corrosion inhibitor coating for aluminum alloys has not been evaluated.This work includes the development of a new,lightweight,high surface area and efficient coating of PANNFs that produced using electrospinning process to resist the corrosion of aluminum alloys(AA5083)which immersed in 0.6 M NaCl at alkaline medium(pH=12)and acidic medium(pH=1)at a range of temperatures(293–323)K.The PANNFs coating was successfully deposited on AA 5083 specimens,where these samples were considered as a collector electrode in the electrospinning process.The corrosion experiments of the aluminum alloys coated with PANNFs before and after immersion in both corrosive mediums were investigated using cyclic potential polarization(CPP).The results confirmed that the PANNFs coating was able to protect the surface of the aluminum specimens from corrosion,by reducing the corrosion current and increasing the surface polarization resistance,thus reducing the corrosion rate.The protection efficiency was found in the alkaline medium 98.8%while in the acidic medium 83.3%.So,it was in both mediums decreased with the increase in temperature.The shape,distribution and size of the polymeric nanofibers that formed the coating were also examined using field emission scanning electron microscopy(FE-SEM)and the percentages of the structural components of these fibers were detected using the X-ray dispersion spectroscopy(EDS).The surface of aluminum specimens was completely covered by PANNFs.These electrospun nanofibers have worn out and lined up spacing after immersion in the corrosive mediums.The diameters average of PANNFs was found to be about 200 and 150 nm before and after immersion,respectively.
文摘The hottest topic now among Europe's automotive industry is CO2. The European Union has set the goal. By 2012, all Europe-based car makers would have to reduce the per car CO2 level to as low as 120-130g/km from the current 160g/km.
基金Our research was funded by open project(ESP15004)from the Ecological Security and Protection Key Laboratory of Sichuan Province,Mianyang Normal University.
文摘The flagship species conservation strategy is widely practiced in nature reserves.However,few studies have quantitatively explored whether the current functional zoning adequately conserves the habitats of other species.To examine this problem,we selected the Tangjiahe,Xuebaoding,and Wanglang national nature reserves in southwest China and tested the protective efficiency of the giant panda(Ailuropoda melanoleuca)reserves on a local herbivore—Sichuan takin(Budorcas taxicolor tibetana)in functional zoning.We predicted that the habitat distribution of the Sichuan takin with Maxent and habitat suitability would be classified as very low,low,moderately,or highly suitable.We calculated the percentage of each type of habitat class across the core,buffer,and experimental zones in these reserves and introduced an economic index present value index to further assess the efficacy of the functional zoning in conserving the habitat of Sichuan takin.Our findings indicate that suitable habitat distributions of Sichuan takin are multicore and influenced by diverse variables in different nature reserves.The percentage of moderately suitable and highly suitable habitat in the core zone is 69%and 54%in Tangjiahe,76%and 75%in Wanglang,and 47%and 28%in Xuebaoding,respectively.The present value index of moderately and highly suitable habitat is 1.01 and 0.79(Tangjiahe),0.87 and 0.86(Wanglang),0.76 and 0.44(Xuebaoding),respectively.The efficiency of functional zoning on Sichuan takin seems lower than imagined in giant panda reserves,and species that have important impacts on local ecosystem need further estimation and greater focus.
文摘Green manufacturing is a new way out for the auto industry—ZHAO Hang, president of CATARC The green manufacturing means a lot, in terms of the manufacturing process, material and techniques. China spares no efforts to producing vehicles and it