The aim of this study was to investigate the effects of light intensity and enhanced nitrogen supply on the growth and photosynthesis of the green-tide macroalga, Ulvaprolifera. Thalli of U. prolifera were grown in na...The aim of this study was to investigate the effects of light intensity and enhanced nitrogen supply on the growth and photosynthesis of the green-tide macroalga, Ulvaprolifera. Thalli of U. prolifera were grown in natural or NH^-enriched seawater under two different light intensities for 7 days, and then the growth rate, pigmentation, and photosynthetic performance of the thalli were evaluated. The results show that the relative growth rate （RGR） was markedly higher under the high light level than under the low light level. Enrichment with NH~ enhanced the RGR under high light intensity, but did not affect RGR under low light intensity. In low light conditions, NH;-enrichment resulted in a marked decrease in the maximal photosynthetic rate （Pro） and the maximum carbon fixation rate （Vmax）, but it did not affect the half saturation constant for carbon （K0.5） or the ratio of Vmax to K0.5, which reflects the carbon acquisition efficiency. In high light conditions, Pm, K05, and the dark respiration rate （Rd） increased under NHI enrichment, but Vmax and the Vmax/Ko5 ratio decreased. Regardless of the light intensity, NH^＋4-enrichment did not affect the apparent photosynthetic efficiency （a）, which reflects the ability of the alga to use light energy at low light levels. Under both low and high light intensities, the chlorophyll a （Chl a）, chlorophyll b （Chl b）, and carotenoids （Car） contents in thalli were higher in NH1-enriched than in natural seawater, except that there was a decrease in the Chl b content of thalli in NH1-enriched seawater under low light intensity. Therefore, NH^＋4 enrichment improved the growth and photosynthetic performance of U. prolifera under high light intensity, but not under low light intensity. We discuss the possible mechanisms underlying these physiological responses.展开更多
The oxygen-enriched direct smelting of jamesonite concentrate was carried out at 1250℃by changing the slag composition.The effects of Fe/SiO2 and Ca O/SiO2 mass ratios on the metal recovery rate as well as metal cont...The oxygen-enriched direct smelting of jamesonite concentrate was carried out at 1250℃by changing the slag composition.The effects of Fe/SiO2 and Ca O/SiO2 mass ratios on the metal recovery rate as well as metal content in slag were investigated.Experimental results indicated that the metal(Pb+Sb)recovery rate was up to 88.30%,and metal(Pb+Sb)content in slag was below 1 wt.%under the condition of slag composition of 21-22 wt.%Fe,19-20 wt.%SiO2 and 17-18 wt.%Ca O with Fe/SiO2 mass ratio of 1.1:1 and Ca O/SiO2 mass ratio of 0.9:1.The microanalysis of the alloy and slag demonstrated that the main phases in the alloy contained metallic Pb,metallic Sb and a small amount of Cu2 Sb and Fe Sb2 intermetallic compounds.The slag was mainly composed of kirschsteinite and fayalite.Zinc in the raw material was mainly oxidized into the slag phase in the form of zinc oxide.展开更多
Most of existing works on complex network assumed that the nodes and edges were uncapacitated during the evolving process,and displayed "rich club" phenomenon.Here we will show that the "rich club"...Most of existing works on complex network assumed that the nodes and edges were uncapacitated during the evolving process,and displayed "rich club" phenomenon.Here we will show that the "rich club" could be changed to "common rich" if we consider the node capacity.In this paper,we define the node and edge attractive index with node capacity,and propose a new evolving model on the base of BBV model,with evolving simulations of the networks.In the new model,an entering node is linked with an existing node according to the preferential attachment mechanism defined with the attractive index of the existing node.We give the theoretical approximation and simulation solutions.If node capacity is finite,the rich node may not be richer further when the node strength approaches or gets to the node capacity.This is confirmed by analyzing the passenger traffic and routes of Chinese main airports.Due to node strength being function of time t,we can use the theoretical approximation solution to forecast how node strength changes and the time when node strength reaches its maximum value.展开更多
基金Supported by the National Natural Science Foundation of China(No.41376129)the Public Science and Technology Research Funds Projects of Ocean(Nos.201305005,201305021,201105008-2)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK2011400)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA11020404-1)
文摘The aim of this study was to investigate the effects of light intensity and enhanced nitrogen supply on the growth and photosynthesis of the green-tide macroalga, Ulvaprolifera. Thalli of U. prolifera were grown in natural or NH^-enriched seawater under two different light intensities for 7 days, and then the growth rate, pigmentation, and photosynthetic performance of the thalli were evaluated. The results show that the relative growth rate （RGR） was markedly higher under the high light level than under the low light level. Enrichment with NH~ enhanced the RGR under high light intensity, but did not affect RGR under low light intensity. In low light conditions, NH;-enrichment resulted in a marked decrease in the maximal photosynthetic rate （Pro） and the maximum carbon fixation rate （Vmax）, but it did not affect the half saturation constant for carbon （K0.5） or the ratio of Vmax to K0.5, which reflects the carbon acquisition efficiency. In high light conditions, Pm, K05, and the dark respiration rate （Rd） increased under NHI enrichment, but Vmax and the Vmax/Ko5 ratio decreased. Regardless of the light intensity, NH^＋4-enrichment did not affect the apparent photosynthetic efficiency （a）, which reflects the ability of the alga to use light energy at low light levels. Under both low and high light intensities, the chlorophyll a （Chl a）, chlorophyll b （Chl b）, and carotenoids （Car） contents in thalli were higher in NH1-enriched than in natural seawater, except that there was a decrease in the Chl b content of thalli in NH1-enriched seawater under low light intensity. Therefore, NH^＋4 enrichment improved the growth and photosynthetic performance of U. prolifera under high light intensity, but not under low light intensity. We discuss the possible mechanisms underlying these physiological responses.
基金Project(51474248)supported by the National Natural Science Foundation of China
文摘The oxygen-enriched direct smelting of jamesonite concentrate was carried out at 1250℃by changing the slag composition.The effects of Fe/SiO2 and Ca O/SiO2 mass ratios on the metal recovery rate as well as metal content in slag were investigated.Experimental results indicated that the metal(Pb+Sb)recovery rate was up to 88.30%,and metal(Pb+Sb)content in slag was below 1 wt.%under the condition of slag composition of 21-22 wt.%Fe,19-20 wt.%SiO2 and 17-18 wt.%Ca O with Fe/SiO2 mass ratio of 1.1:1 and Ca O/SiO2 mass ratio of 0.9:1.The microanalysis of the alloy and slag demonstrated that the main phases in the alloy contained metallic Pb,metallic Sb and a small amount of Cu2 Sb and Fe Sb2 intermetallic compounds.The slag was mainly composed of kirschsteinite and fayalite.Zinc in the raw material was mainly oxidized into the slag phase in the form of zinc oxide.
基金supported by the National Natural Science Foundation of China (Grant Nos.71171111,70771046 and 71201081)the Colleges Graduate Research and Innovation Program of Jiangsu Province (Grant Nos.CXZZ11-0220 and CX10B-102Z)
文摘Most of existing works on complex network assumed that the nodes and edges were uncapacitated during the evolving process,and displayed "rich club" phenomenon.Here we will show that the "rich club" could be changed to "common rich" if we consider the node capacity.In this paper,we define the node and edge attractive index with node capacity,and propose a new evolving model on the base of BBV model,with evolving simulations of the networks.In the new model,an entering node is linked with an existing node according to the preferential attachment mechanism defined with the attractive index of the existing node.We give the theoretical approximation and simulation solutions.If node capacity is finite,the rich node may not be richer further when the node strength approaches or gets to the node capacity.This is confirmed by analyzing the passenger traffic and routes of Chinese main airports.Due to node strength being function of time t,we can use the theoretical approximation solution to forecast how node strength changes and the time when node strength reaches its maximum value.
