Three harmful algal bloom （HAB） species, Phaeocystis globosa, Thalassiosira rotula, and Prorocentrum donghaiense were isolated from the coast of China and cultured in batches at three light intensities （40, 70 and ...Three harmful algal bloom （HAB） species, Phaeocystis globosa, Thalassiosira rotula, and Prorocentrum donghaiense were isolated from the coast of China and cultured in batches at three light intensities （40, 70 and 150 μmol photons · m -2 · s -1 ）. The variation patterns of cell numbers and growth rates with light intensity during growth process were different among species. In P. globosa and T. rotula, maximum growth rates were found at 150 μmol photons · m -2 · s -1 and ranged from 0.60 divisions per day in T. rotula, to 1.17 divisions per day in P. globosa. The highest growth rate of P. donghaiense, however, was found at 70 μmol photons · m -2 · s -1 （0.36 divisions per day）. In general, all the three HAB species showed adaptation to increasing light intensity by decreasing cellular concentrations of chlorophyll a （Chl a）, but the variation patterns during the growth process were species-specific. The cellular concentrations of Chl a in P. donghaiense and T. rotula increased gradually with incubation time, but the opposite trend was found in P. globosa. Most of the pigment ratios and pigment indices of these three species were nearly constant during the growth process and showed small changes at different light intensities illustrating the applicability of chemotaxonomy during the initial and developing stages of HAB events, which is very important to study the ecological issues related to HAB species. Ratios of photoprotective carotenoids, such as diadinoxanthin, diatoxanthin and β, β-carotene to total chlorophylls a （Tchl a） showed the trend of increasing with the increase of light intensity during growth process. The species-specific and pigment-specific variations in pigment ratios/indices at different light intensities during growth process probably reflected the differences in the pigment composition as well as the adaption capabilities of different species to the changes of physical conditions.展开更多
The Shihongtan uranium deposit in northwest China is a sandstone-type deposit suitable for alkaline in-situ leaching exploitation of uranium. Alkaline leaching tends to result in CaCO3 precipitation there by affecting...The Shihongtan uranium deposit in northwest China is a sandstone-type deposit suitable for alkaline in-situ leaching exploitation of uranium. Alkaline leaching tends to result in CaCO3 precipitation there by affecting the porosity of the ore-bearing aquifer. CaCO3 deposits can also block pumping and injection holes if the formulation parameters of the leaching solution are not well controlled. However, controlling these parameters to operate the in-situ leaching process is challenging. Our study demonstrates that the dissolved uranium concentration in the leaching solution increases as HCO3-concentration increases. Therefore, the most suitable HCO3-concentration to use as leaching solution is defined by the boundary value of the HCO3-concentration that controls CaCO3 dissolution-precipitation. That is, the dissolution and precipitation of calcite is closely related to pH, Ca2+ and HCO3-concentration. The pH and Ca2+ concentration are the main factors limiting HCO3-concentration in the leaching solution. The higher the pH and Ca2+ concentration, the lower the boundary value of HCO3-concentration, and therefore the more unfavorable to in-situ leaching of uranium.展开更多
[Objectives]To detect content of Pb,Cd,Hg,As,Cu,Zn,and Cr in Lysimachia christinae,and to analyze the pollution level.[Methods]Seven kinds of elements in L.christinae were determined by Inductively coupled plasma mass...[Objectives]To detect content of Pb,Cd,Hg,As,Cu,Zn,and Cr in Lysimachia christinae,and to analyze the pollution level.[Methods]Seven kinds of elements in L.christinae were determined by Inductively coupled plasma mass spectrometry and analyzed by single index and comprehensive index.[Results]The seven heavy metal elements showed good linearity in their respective concentration ranges.The recoveries of the samples were 84.5%-109.5%,and the RSD values were 2.30%-5.10%.Comparing the measured results of heavy metal elements with the limit values stipulated in the 2020 edition of the Chinese Pharmacopoeia and other standards,the Cr element in 19 batches of samples exceeded the standard,and the Zn element in 7 batches of samples exceeded the standard.The exceeding rates were 100.0%and 36.8%,respectively;the content of other heavy metal elements did not exceed the standard.The order of individual index from large to small was Cr,Zn,Cd,Hg,Cu,As,and Pb,and the average comprehensive pollution level was mild pollution and above.[Conclusions]L.christinae was mainly polluted by Cr,followed by Zn;this study can provide basic data for drafting of the limit standard for heavy metal elements in L.christinae.展开更多
基金The National Natural Science Foundation of China(NSFC)under contract Nos40806029 and 40676068the National High Technology Research and Development Program of China(863)under contract No.2006AA09Z178
文摘Three harmful algal bloom （HAB） species, Phaeocystis globosa, Thalassiosira rotula, and Prorocentrum donghaiense were isolated from the coast of China and cultured in batches at three light intensities （40, 70 and 150 μmol photons · m -2 · s -1 ）. The variation patterns of cell numbers and growth rates with light intensity during growth process were different among species. In P. globosa and T. rotula, maximum growth rates were found at 150 μmol photons · m -2 · s -1 and ranged from 0.60 divisions per day in T. rotula, to 1.17 divisions per day in P. globosa. The highest growth rate of P. donghaiense, however, was found at 70 μmol photons · m -2 · s -1 （0.36 divisions per day）. In general, all the three HAB species showed adaptation to increasing light intensity by decreasing cellular concentrations of chlorophyll a （Chl a）, but the variation patterns during the growth process were species-specific. The cellular concentrations of Chl a in P. donghaiense and T. rotula increased gradually with incubation time, but the opposite trend was found in P. globosa. Most of the pigment ratios and pigment indices of these three species were nearly constant during the growth process and showed small changes at different light intensities illustrating the applicability of chemotaxonomy during the initial and developing stages of HAB events, which is very important to study the ecological issues related to HAB species. Ratios of photoprotective carotenoids, such as diadinoxanthin, diatoxanthin and β, β-carotene to total chlorophylls a （Tchl a） showed the trend of increasing with the increase of light intensity during growth process. The species-specific and pigment-specific variations in pigment ratios/indices at different light intensities during growth process probably reflected the differences in the pigment composition as well as the adaption capabilities of different species to the changes of physical conditions.
基金supported by the basic science research project (A3420060142) from China National Defence Science and Technology Industry BureauChina National Natural Science Fund Project (40872165)
文摘The Shihongtan uranium deposit in northwest China is a sandstone-type deposit suitable for alkaline in-situ leaching exploitation of uranium. Alkaline leaching tends to result in CaCO3 precipitation there by affecting the porosity of the ore-bearing aquifer. CaCO3 deposits can also block pumping and injection holes if the formulation parameters of the leaching solution are not well controlled. However, controlling these parameters to operate the in-situ leaching process is challenging. Our study demonstrates that the dissolved uranium concentration in the leaching solution increases as HCO3-concentration increases. Therefore, the most suitable HCO3-concentration to use as leaching solution is defined by the boundary value of the HCO3-concentration that controls CaCO3 dissolution-precipitation. That is, the dissolution and precipitation of calcite is closely related to pH, Ca2+ and HCO3-concentration. The pH and Ca2+ concentration are the main factors limiting HCO3-concentration in the leaching solution. The higher the pH and Ca2+ concentration, the lower the boundary value of HCO3-concentration, and therefore the more unfavorable to in-situ leaching of uranium.
基金Supported by Risk Monitoring Task Project of Chongqing Drug Administration in 2020。
文摘[Objectives]To detect content of Pb,Cd,Hg,As,Cu,Zn,and Cr in Lysimachia christinae,and to analyze the pollution level.[Methods]Seven kinds of elements in L.christinae were determined by Inductively coupled plasma mass spectrometry and analyzed by single index and comprehensive index.[Results]The seven heavy metal elements showed good linearity in their respective concentration ranges.The recoveries of the samples were 84.5%-109.5%,and the RSD values were 2.30%-5.10%.Comparing the measured results of heavy metal elements with the limit values stipulated in the 2020 edition of the Chinese Pharmacopoeia and other standards,the Cr element in 19 batches of samples exceeded the standard,and the Zn element in 7 batches of samples exceeded the standard.The exceeding rates were 100.0%and 36.8%,respectively;the content of other heavy metal elements did not exceed the standard.The order of individual index from large to small was Cr,Zn,Cd,Hg,Cu,As,and Pb,and the average comprehensive pollution level was mild pollution and above.[Conclusions]L.christinae was mainly polluted by Cr,followed by Zn;this study can provide basic data for drafting of the limit standard for heavy metal elements in L.christinae.
