Sixteen Scenedesmus species or strains have been employed to investigate the maximum capacity of nickel (Ni) accumulation in 10 mg/L Ni solution. The results showed that the capacity of accumulating Ni from aqueou...Sixteen Scenedesmus species or strains have been employed to investigate the maximum capacity of nickel (Ni) accumulation in 10 mg/L Ni solution. The results showed that the capacity of accumulating Ni from aqueous solution in 16 Scenedesmus species or strains showed the diversity. S. quadricauda freshwater algae culture collection of the Institute of Hydrobiology (FACHB) 44 and S. quadricauda FACHB 506 performed much more capacity of Ni accumulation than other species such as Scenedesmus sp. FACHB 416 and Scenedesmus sp. FACHB 489. Sequestration of Ni ions from aqueous solution was very efficient (26.7 mg Ni/g dry weight, in the 100 mg/L Ni solution) in S. quadricauda FACHB 44. The kinetics of Ni binding indicated that Ni bioaccumulation, in algal cell of S. quadricauda FACHB 44, possessed a rapid biosorption (5 min) and an slow bioaccumulation (2-3 h). More than 70% of Ni binding in algal cell were accumulated by biosorption and the remaining 20%-30% were bioaccumulated by energy_consumed transportation. It is much more higher ratio of energy_consumed transportation in S. quadricauda FACHB 44 than in other algae. Both the transmission electron microscope (TEM) and the energy_dispersive X_ray (EDX) microanalyses also revealed the different mechanisms of bioaccumulation in the various subcellular regions: a very fast adsorption in the cell wall; and a time_dependent absorption in protoplasm, specially in starch and chromatin.展开更多
Cyclic thermal exposure tests of infrared heating to 800 ℃ in 120 s followed by compressed air cooling to 150 ℃ in 60 s were performed for the laser deposited Ti60A （Ti5.54Al3.38Sn3.34Zr0.37Mo0.46Si） alloy. The ef...Cyclic thermal exposure tests of infrared heating to 800 ℃ in 120 s followed by compressed air cooling to 150 ℃ in 60 s were performed for the laser deposited Ti60A （Ti5.54Al3.38Sn3.34Zr0.37Mo0.46Si） alloy. The effects of thermal exposure cycles on length ofβphase, area fraction ofαphase and microhardness of alloy were examined by OM, SEM and EDS. The results indicate that thermal exposure cycles have significant effects on length ofβphase, area fraction ofαphase and microhardness of the alloy. The original fine basket-weaveβand 78.5%αtransform to transient wedge-likeβ, finally leaving granularβand 97.6%coarsenedαwith the increased thermal exposure cycles. The formation mechanism of coarsenedαand broken-upβmicrostructure is discussed. The alloy after 750 thermal exposure cycles has the maximum microhardness, 33.3%higher than that of the as-deposited alloy.展开更多
Abstract： Based on the analysis of core samples from the hole of Zk23 in the East China Sea Continental Shelf and by means of sedimentary stratigraphy, biostratigraphy and chronostratigraphy, the authors consider tha...Abstract： Based on the analysis of core samples from the hole of Zk23 in the East China Sea Continental Shelf and by means of sedimentary stratigraphy, biostratigraphy and chronostratigraphy, the authors consider that the fine-sand deposition in borehole was part of buried ancient estuary sand ridges of the Yangtze River. The deposition history of study area around the hole before and after the glacial period as well as postglacial period is made clear after our research： （1） the estuarine sublayer -undersea delta facies strata was deposited under the fast sea level rise about 15 kaB.P; （2） sand ridges mostly consisting of fine-sand, were formed when the sea level was the fluctuant range of 60 - 80 m of isoba during the deglacial period around 15 - 12 kaB.P; （3） first silty clay and clay silt strata above the sand ridges were deposited during the period when the sea level rose fast from 12 to 7 kaB.P, and then it keeps stable to the present.展开更多
The electrodeposition of lead in alkaline solutions containing xylitol （1, 2, 3, 4, 5-pentahydroxypentane） was studied. The lead electrodeposition and the chemical stability of xylitol in alkaline solutions were inv...The electrodeposition of lead in alkaline solutions containing xylitol （1, 2, 3, 4, 5-pentahydroxypentane） was studied. The lead electrodeposition and the chemical stability of xylitol in alkaline solutions were investigated by cyclic voltammetry. Apparent activation energy, apparent transfer coefficient and exchange current density were obtained by linear sweep voltammetry. Initial stages of lead electrocrystallization were determined by chronoamperometry. Voltammograms of a AISI 316 stainless steel electrode in xylitol solution exhibit no current in the potential range of-1.3 V to 0.75 V （vs Hg/HgO）, implying that xylitol is stable to oxidation and reduction. The apparent activation energy, apparent transfer coefficient and exchange current density were calculated to be 35.15 kJ/mol, 1.56 and 9.65x10^-5 A/m^2. Analysis of the chronoamperometric responses implies three-dimensional growth of nuclei, with the type of nucleation depending on overpotential.展开更多
Core D （21°23′02″N, 116°47′13″E, water depth 405 m） was sampled from the upper slope from the northeastern South China Sea （SCS） and applied to analyze the sedimentary environmental change in this se...Core D （21°23′02″N, 116°47′13″E, water depth 405 m） was sampled from the upper slope from the northeastern South China Sea （SCS） and applied to analyze the sedimentary environmental change in this sea area since the last glacial stage. The results of grain size analysis, diatom analysis and detrital mineral analysis were well matched. We divided the core D into two layers. The surface sand layer （0 - 2 cm） consisted of residual sediments, which might be originally the sediment in the late Pleistocene and later suffered from being transformed in the post glacial transgression. The lower layer （2 - 130 cm） was quite different from the surface one, which might mainly result from a neritic sedimentary environment in the last glacial stage. Two sedimentary cycles could be detected in the core D： regression during Marine isotope stage （MIS） 4 to transgression during MIS 3 and regression during MIS 2 to transgression during the post glacial.展开更多
By way of bactericidal halo test, the antibacterial performance of various electroplated deposits (cobalt, zinc, copper, silver, gold, nickel, chromium, cobalt-containing alloy of nickel, and nickel-containing alloy o...By way of bactericidal halo test, the antibacterial performance of various electroplated deposits (cobalt, zinc, copper, silver, gold, nickel, chromium, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt) were determined. The results of the test show that the electroplated deposits of zinc, cobalt, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt, silver and copper possess a distinct antibacterial capability against the growth of pathogenic bacteria tested, and that SUS304 stainless steel and chromium deposit have no antibacterial activity. The relationship between the antibacterial capability and the rest potentials of the deposits was investigated. It was found that the higher the antibacterial activity of the electroplated deposit was, the more negative the rest potential of deposit was.展开更多
The establishment of water circulation aquaculture system realized the hi- erarchical use of nitrogen, phosphorus and other eutrophic substances in aquaculture wastewater and the recirculation use of water resource. H...The establishment of water circulation aquaculture system realized the hi- erarchical use of nitrogen, phosphorus and other eutrophic substances in aquaculture wastewater and the recirculation use of water resource. However, no research has been reported on the detailed calculation of the relationship between the area of aquaculture pond and purification pond. In this study, referring to the absorption ability of aquatic plants to pollutants in aquaculture wastewater and pollutant generation and discharge coefficient in aquaculture pond, based on the general rules of water quality management in freshwater aquaculture system, a calculation mode was es- tablished to investigate the relationship between the area of aquaculture pond and purification pond in freshwater recirculation aquaculture system, which was feasible to explain related cases and would provide theoretical basis to reduce the economic costs in the construction of water circulation aquaculture system and realize the bal- ance between the ecological benefits and the economic benefits.展开更多
Refer to the Hamiltonian system, first integrals of the Birkhoffian system can be found by using of the perfect differential method. Through these first integrals, the order of the Birkhoffian system can be reduced. T...Refer to the Hamiltonian system, first integrals of the Birkhoffian system can be found by using of the perfect differential method. Through these first integrals, the order of the Birkhoffian system can be reduced. Then according to the alternate of the coordinate, a kind of new partial differential operator was defined in order to hold the Birkhoff form. The result shows that the Birkhoffian system has generalized energy integrals and cyclic integrals. Furthermore, each integral can reduce the order of equations two degrees.展开更多
The concentrations, accumulation and sources of 15 polycyclic aromatic hydrocarbons （PAHs） had been studied or evaluated in the surface layer sediments of Taizhou Bay, China. It showed that the concentrations of PAH...The concentrations, accumulation and sources of 15 polycyclic aromatic hydrocarbons （PAHs） had been studied or evaluated in the surface layer sediments of Taizhou Bay, China. It showed that the concentrations of PAHs ranged from 85.4 to 167.6 ng/g （averaged 138.62 ng/g）, and the highest level was found in Jiao Jiang Dock. Percentages of 2-, 3-, 4-, 5- and 6-cyclic aromatic hydrocarbons were 7.8 %, 42.1%, 33.3 %, 9.6 % and 7.2 % respectively. The accumulation indices of PAHs ranged from 532.7 to 1068.9 （averaged 807.5）, and the index of Phenanthrene was the highest （122.7）, while that of Benzo （a） Pyrene was the lowest （2.7） among them. In Taizhou Bay, PAHs in surface layer sediments came mainly from coal burning, partly from direct pollution of petroleum hydrocarbons.展开更多
文摘Sixteen Scenedesmus species or strains have been employed to investigate the maximum capacity of nickel (Ni) accumulation in 10 mg/L Ni solution. The results showed that the capacity of accumulating Ni from aqueous solution in 16 Scenedesmus species or strains showed the diversity. S. quadricauda freshwater algae culture collection of the Institute of Hydrobiology (FACHB) 44 and S. quadricauda FACHB 506 performed much more capacity of Ni accumulation than other species such as Scenedesmus sp. FACHB 416 and Scenedesmus sp. FACHB 489. Sequestration of Ni ions from aqueous solution was very efficient (26.7 mg Ni/g dry weight, in the 100 mg/L Ni solution) in S. quadricauda FACHB 44. The kinetics of Ni binding indicated that Ni bioaccumulation, in algal cell of S. quadricauda FACHB 44, possessed a rapid biosorption (5 min) and an slow bioaccumulation (2-3 h). More than 70% of Ni binding in algal cell were accumulated by biosorption and the remaining 20%-30% were bioaccumulated by energy_consumed transportation. It is much more higher ratio of energy_consumed transportation in S. quadricauda FACHB 44 than in other algae. Both the transmission electron microscope (TEM) and the energy_dispersive X_ray (EDX) microanalyses also revealed the different mechanisms of bioaccumulation in the various subcellular regions: a very fast adsorption in the cell wall; and a time_dependent absorption in protoplasm, specially in starch and chromatin.
基金Project(2010CB731705)supported by the National Basic Research Program of China
文摘Cyclic thermal exposure tests of infrared heating to 800 ℃ in 120 s followed by compressed air cooling to 150 ℃ in 60 s were performed for the laser deposited Ti60A （Ti5.54Al3.38Sn3.34Zr0.37Mo0.46Si） alloy. The effects of thermal exposure cycles on length ofβphase, area fraction ofαphase and microhardness of alloy were examined by OM, SEM and EDS. The results indicate that thermal exposure cycles have significant effects on length ofβphase, area fraction ofαphase and microhardness of the alloy. The original fine basket-weaveβand 78.5%αtransform to transient wedge-likeβ, finally leaving granularβand 97.6%coarsenedαwith the increased thermal exposure cycles. The formation mechanism of coarsenedαand broken-upβmicrostructure is discussed. The alloy after 750 thermal exposure cycles has the maximum microhardness, 33.3%higher than that of the as-deposited alloy.
文摘Abstract： Based on the analysis of core samples from the hole of Zk23 in the East China Sea Continental Shelf and by means of sedimentary stratigraphy, biostratigraphy and chronostratigraphy, the authors consider that the fine-sand deposition in borehole was part of buried ancient estuary sand ridges of the Yangtze River. The deposition history of study area around the hole before and after the glacial period as well as postglacial period is made clear after our research： （1） the estuarine sublayer -undersea delta facies strata was deposited under the fast sea level rise about 15 kaB.P; （2） sand ridges mostly consisting of fine-sand, were formed when the sea level was the fluctuant range of 60 - 80 m of isoba during the deglacial period around 15 - 12 kaB.P; （3） first silty clay and clay silt strata above the sand ridges were deposited during the period when the sea level rose fast from 12 to 7 kaB.P, and then it keeps stable to the present.
基金Project(2007CB613604)supported by the National Basic Research Program of China
文摘The electrodeposition of lead in alkaline solutions containing xylitol （1, 2, 3, 4, 5-pentahydroxypentane） was studied. The lead electrodeposition and the chemical stability of xylitol in alkaline solutions were investigated by cyclic voltammetry. Apparent activation energy, apparent transfer coefficient and exchange current density were obtained by linear sweep voltammetry. Initial stages of lead electrocrystallization were determined by chronoamperometry. Voltammograms of a AISI 316 stainless steel electrode in xylitol solution exhibit no current in the potential range of-1.3 V to 0.75 V （vs Hg/HgO）, implying that xylitol is stable to oxidation and reduction. The apparent activation energy, apparent transfer coefficient and exchange current density were calculated to be 35.15 kJ/mol, 1.56 and 9.65x10^-5 A/m^2. Analysis of the chronoamperometric responses implies three-dimensional growth of nuclei, with the type of nucleation depending on overpotential.
文摘Core D （21°23′02″N, 116°47′13″E, water depth 405 m） was sampled from the upper slope from the northeastern South China Sea （SCS） and applied to analyze the sedimentary environmental change in this sea area since the last glacial stage. The results of grain size analysis, diatom analysis and detrital mineral analysis were well matched. We divided the core D into two layers. The surface sand layer （0 - 2 cm） consisted of residual sediments, which might be originally the sediment in the late Pleistocene and later suffered from being transformed in the post glacial transgression. The lower layer （2 - 130 cm） was quite different from the surface one, which might mainly result from a neritic sedimentary environment in the last glacial stage. Two sedimentary cycles could be detected in the core D： regression during Marine isotope stage （MIS） 4 to transgression during MIS 3 and regression during MIS 2 to transgression during the post glacial.
文摘By way of bactericidal halo test, the antibacterial performance of various electroplated deposits (cobalt, zinc, copper, silver, gold, nickel, chromium, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt) were determined. The results of the test show that the electroplated deposits of zinc, cobalt, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt, silver and copper possess a distinct antibacterial capability against the growth of pathogenic bacteria tested, and that SUS304 stainless steel and chromium deposit have no antibacterial activity. The relationship between the antibacterial capability and the rest potentials of the deposits was investigated. It was found that the higher the antibacterial activity of the electroplated deposit was, the more negative the rest potential of deposit was.
基金Supported by Special Fund for the Construction of Modern Agricultural Industry Technology System(CARS-46)Special Fund for Basic Research and Operating Expenses of Central-level Research Institutes(2007JBFA03)~~
文摘The establishment of water circulation aquaculture system realized the hi- erarchical use of nitrogen, phosphorus and other eutrophic substances in aquaculture wastewater and the recirculation use of water resource. However, no research has been reported on the detailed calculation of the relationship between the area of aquaculture pond and purification pond. In this study, referring to the absorption ability of aquatic plants to pollutants in aquaculture wastewater and pollutant generation and discharge coefficient in aquaculture pond, based on the general rules of water quality management in freshwater aquaculture system, a calculation mode was es- tablished to investigate the relationship between the area of aquaculture pond and purification pond in freshwater recirculation aquaculture system, which was feasible to explain related cases and would provide theoretical basis to reduce the economic costs in the construction of water circulation aquaculture system and realize the bal- ance between the ecological benefits and the economic benefits.
文摘Refer to the Hamiltonian system, first integrals of the Birkhoffian system can be found by using of the perfect differential method. Through these first integrals, the order of the Birkhoffian system can be reduced. Then according to the alternate of the coordinate, a kind of new partial differential operator was defined in order to hold the Birkhoff form. The result shows that the Birkhoffian system has generalized energy integrals and cyclic integrals. Furthermore, each integral can reduce the order of equations two degrees.
文摘The concentrations, accumulation and sources of 15 polycyclic aromatic hydrocarbons （PAHs） had been studied or evaluated in the surface layer sediments of Taizhou Bay, China. It showed that the concentrations of PAHs ranged from 85.4 to 167.6 ng/g （averaged 138.62 ng/g）, and the highest level was found in Jiao Jiang Dock. Percentages of 2-, 3-, 4-, 5- and 6-cyclic aromatic hydrocarbons were 7.8 %, 42.1%, 33.3 %, 9.6 % and 7.2 % respectively. The accumulation indices of PAHs ranged from 532.7 to 1068.9 （averaged 807.5）, and the index of Phenanthrene was the highest （122.7）, while that of Benzo （a） Pyrene was the lowest （2.7） among them. In Taizhou Bay, PAHs in surface layer sediments came mainly from coal burning, partly from direct pollution of petroleum hydrocarbons.
