Heavy metal pollution has become a worldwide problem in aquaculture. We studied copper （Cu^2＋） accumulation and physiological responses of two red algae Gracilaria lemaneiformis and Gracilaria lichenoides from Chin...Heavy metal pollution has become a worldwide problem in aquaculture. We studied copper （Cu^2＋） accumulation and physiological responses of two red algae Gracilaria lemaneiformis and Gracilaria lichenoides from China under Cu^2＋ exposure of 0-500 μg/L in concentration. Compared with G. lemaneiformis, G. lichenoides was more capable in accumulating Cu^2＋, specifically, more Cu〉 on extracellular side （cell wall） than on intracellular side （cytoplasm） and in cell organelles （especially chloroplast, cell nucleus, mitochondria, and ribosome）. In addition, G. lichenoides contained more insoluble polysaccharide in cell wall, which might promote the extracellular Cu^2＋-binding as an efficient barrier against metal toxicity. Conversely, G. lemaneiformis was more vulnerable than G. lichenoides to Cu^2＋ toxin for decreases in growth, pigment （chlorophyll a, chlorophyll b, phycobiliprotein, and B-carotene） content, and photosynthetic activity. Moreover, more serious oxidative damages in G. lemaneiformis than in G. lichenoides, in accumulation of reactive oxidative species and malondialdehyde, and in electrolyte leakage, because of lower antioxidant enzyme （superoxide dismutase and glutathione reductase） activities. Therefore, G. lichenoides was less susceptible to Cu〉 stress than G. lemaneiformis.展开更多
Hongxing reservoir was constructed on the floodplain of Hulan River in Heilongjiang. The geological problem of the reservoir is the seepage of the dam base and its related seepage stability. The leakage of the reservo...Hongxing reservoir was constructed on the floodplain of Hulan River in Heilongjiang. The geological problem of the reservoir is the seepage of the dam base and its related seepage stability. The leakage of the reservoir is caused by the water head differences between the upstream and downstream of the dam. Severe seepage could decrease the engineering benefits of the reservoir. Moreover,infiltration function of water will influence the safety of the dam. Through the analysis on the granule constitute and the formation of the dam base,the types of the seepage failure apt to happen were defined and the anti-infiltration and the permissible depression ratio were determined. Using the numerical simulation software GMS,the two-dimension numerical modeling has been carried out to analyze the seepage field of the reservoir. Through the two conditions modeling with concrete impervious wall and no concrete impervious wall,the largest flow rate,single-wide seepage discharge and the max infiltration gradient of the dam base were calculated. According to the permeable depression ratio of the dam base,the seepage stability of Hongxing reservoir dam base was analyzed.展开更多
基金Supported by the Society Development Program of the Natural Science Foundation of Jiangsu Province in China (No.BS2002016)
文摘Heavy metal pollution has become a worldwide problem in aquaculture. We studied copper （Cu^2＋） accumulation and physiological responses of two red algae Gracilaria lemaneiformis and Gracilaria lichenoides from China under Cu^2＋ exposure of 0-500 μg/L in concentration. Compared with G. lemaneiformis, G. lichenoides was more capable in accumulating Cu^2＋, specifically, more Cu〉 on extracellular side （cell wall） than on intracellular side （cytoplasm） and in cell organelles （especially chloroplast, cell nucleus, mitochondria, and ribosome）. In addition, G. lichenoides contained more insoluble polysaccharide in cell wall, which might promote the extracellular Cu^2＋-binding as an efficient barrier against metal toxicity. Conversely, G. lemaneiformis was more vulnerable than G. lichenoides to Cu^2＋ toxin for decreases in growth, pigment （chlorophyll a, chlorophyll b, phycobiliprotein, and B-carotene） content, and photosynthetic activity. Moreover, more serious oxidative damages in G. lemaneiformis than in G. lichenoides, in accumulation of reactive oxidative species and malondialdehyde, and in electrolyte leakage, because of lower antioxidant enzyme （superoxide dismutase and glutathione reductase） activities. Therefore, G. lichenoides was less susceptible to Cu〉 stress than G. lemaneiformis.
文摘Hongxing reservoir was constructed on the floodplain of Hulan River in Heilongjiang. The geological problem of the reservoir is the seepage of the dam base and its related seepage stability. The leakage of the reservoir is caused by the water head differences between the upstream and downstream of the dam. Severe seepage could decrease the engineering benefits of the reservoir. Moreover,infiltration function of water will influence the safety of the dam. Through the analysis on the granule constitute and the formation of the dam base,the types of the seepage failure apt to happen were defined and the anti-infiltration and the permissible depression ratio were determined. Using the numerical simulation software GMS,the two-dimension numerical modeling has been carried out to analyze the seepage field of the reservoir. Through the two conditions modeling with concrete impervious wall and no concrete impervious wall,the largest flow rate,single-wide seepage discharge and the max infiltration gradient of the dam base were calculated. According to the permeable depression ratio of the dam base,the seepage stability of Hongxing reservoir dam base was analyzed.
