目的采用GC法同时测定不同干燥方式不同部位草珊瑚挥发油中a-蒎稀、蒎稀、(-)-β-蒎稀、柠檬烯、芳樟醇、乙酸龙脑酯、β-榄香烯和β-石竹烯8种成分的含量.方法色谱柱:HP-5毛细管色谱柱(30m x 0.32mm x 0.25μm);检测器:FID;进样口温度:...目的采用GC法同时测定不同干燥方式不同部位草珊瑚挥发油中a-蒎稀、蒎稀、(-)-β-蒎稀、柠檬烯、芳樟醇、乙酸龙脑酯、β-榄香烯和β-石竹烯8种成分的含量.方法色谱柱:HP-5毛细管色谱柱(30m x 0.32mm x 0.25μm);检测器:FID;进样口温度:250T;检测器温度:270t;柱温:5℃为起始温度,保持2min,以•min^-1的速度升至130℃,保持5min;载气:氮气;流速:1 mL•min^-1;进样量:lμL;分流比:30:1结果a-疲烯、蒎稀、(-)-R-蒎稀、柠檬烯、芳樟醇、乙酸龙脑酯、P-榄香烯和β-石竹烯色谱峰分离度良好;进样浓度分别在8.75-1750.00,5.62~1123.60,8.66-1732.80,4.37~873.60 1.96~391.20,4.98-995.60,8.54-1707.60,3.61~721.40μg·mL^-1范围线性良好;平均加样回收率(n=6)分别为98.7%、97.2%、98.2%,98.3%、97.7%、97.5%、9&2%、97.8%,RSD分别为0.62%、1.21%,1.24%、1.30%、1.32%、1.27%、1.57%、0.77%。12批草珊瑚挥发油中a-疲烯、蒎稀、(-)-β-蒎稀、柠檬烯、芳樟醇、乙酸龙脑酯、β-榄香烯和β-石竹烯的含量(n=3)测定结果分别为0~225.50、0~167.06、0~250.34、0~55.66、0~77.91、0~201.98、2.35~294.49、0~14.82.结论该方法准确可靠,适用于草珊瑚挥发油中8个活性成分的含量测定.展开更多
Three types of natural connection between atoll islets are described. Causeway, as an artificial way of connecting islets, makes a connection to be completed in a few months. In this case shore adjustment becomes more...Three types of natural connection between atoll islets are described. Causeway, as an artificial way of connecting islets, makes a connection to be completed in a few months. In this case shore adjustment becomes more vigorous than that in natural conditions, resulting in lagoon shore erosion. A causeway without short bridges or culverts should be built close to the lagoon shore to reduce lagoon shore erosion. A causeway-crossing channel assemblage is the worst type among all of the connection engineering constructions because the crossing channel traps sediment and further transports it out of the channel, resulting in long period coastal erosion. Reforming Nippon Causeway in Tarawa Atoll, Kiribati by simple means will stop sand loss, reduce shore erosion and greatly upgrade its stability.展开更多
Coastal lagoons with small catchment basins are highly sensitive to natural processes and anthropogenic activities. To figure out the environmental changes of a coastal lagoon and its contribution to carbon burial, tw...Coastal lagoons with small catchment basins are highly sensitive to natural processes and anthropogenic activities. To figure out the environmental changes of a coastal lagoon and its contribution to carbon burial, two sediment cores were collected in Xincun Lagoon, southeastern Hainan Island and (210) ~Pb activities, grain size parameters, total organic carbon(TOC), total nitrogen(TN), total inorganic carbon(TIC) and stable carbon isotopes(δ^(13)C) were measured. The results show that in 1770–1815, the decreasing water exchange capacity with outer open water, probably caused by the shifting and narrowing of the tidal inlet, not only diminished the currents and fined the sediments in the lagoon, but also reduced the organic matter of marine sources. From 1815 to 1950, the sedimentary environment of Xincun Lagoon was frequently influenced by storm events. These extreme events resulted in the high fluctuation of sediment grain size and sorting, as well as the great variation in contributions of terrestrial(higher plants, soils) and marine sources(phytoplankton, algae, seagrass). The extremely high content of TIC, compared to TOC before 1950 could be attributed to the large-scale coverage of coral reefs. However, with the boost of seawater aquaculture activities after 1970, the health growth of coral species was severely threatened, and corresponding production and inorganic carbon burial flux reduced. The apparent enhanced inorganic carbon burial rate after 1990 might result from the concomitant carbonate debris produced by seawater aquaculture. This result is important for local government long-term coastal management and environmental planning.展开更多
文摘目的采用GC法同时测定不同干燥方式不同部位草珊瑚挥发油中a-蒎稀、蒎稀、(-)-β-蒎稀、柠檬烯、芳樟醇、乙酸龙脑酯、β-榄香烯和β-石竹烯8种成分的含量.方法色谱柱:HP-5毛细管色谱柱(30m x 0.32mm x 0.25μm);检测器:FID;进样口温度:250T;检测器温度:270t;柱温:5℃为起始温度,保持2min,以•min^-1的速度升至130℃,保持5min;载气:氮气;流速:1 mL•min^-1;进样量:lμL;分流比:30:1结果a-疲烯、蒎稀、(-)-R-蒎稀、柠檬烯、芳樟醇、乙酸龙脑酯、P-榄香烯和β-石竹烯色谱峰分离度良好;进样浓度分别在8.75-1750.00,5.62~1123.60,8.66-1732.80,4.37~873.60 1.96~391.20,4.98-995.60,8.54-1707.60,3.61~721.40μg·mL^-1范围线性良好;平均加样回收率(n=6)分别为98.7%、97.2%、98.2%,98.3%、97.7%、97.5%、9&2%、97.8%,RSD分别为0.62%、1.21%,1.24%、1.30%、1.32%、1.27%、1.57%、0.77%。12批草珊瑚挥发油中a-疲烯、蒎稀、(-)-β-蒎稀、柠檬烯、芳樟醇、乙酸龙脑酯、β-榄香烯和β-石竹烯的含量(n=3)测定结果分别为0~225.50、0~167.06、0~250.34、0~55.66、0~77.91、0~201.98、2.35~294.49、0~14.82.结论该方法准确可靠,适用于草珊瑚挥发油中8个活性成分的含量测定.
基金funded by the Ministry of Foreign Economic Co-operation and Trade,China.
文摘Three types of natural connection between atoll islets are described. Causeway, as an artificial way of connecting islets, makes a connection to be completed in a few months. In this case shore adjustment becomes more vigorous than that in natural conditions, resulting in lagoon shore erosion. A causeway without short bridges or culverts should be built close to the lagoon shore to reduce lagoon shore erosion. A causeway-crossing channel assemblage is the worst type among all of the connection engineering constructions because the crossing channel traps sediment and further transports it out of the channel, resulting in long period coastal erosion. Reforming Nippon Causeway in Tarawa Atoll, Kiribati by simple means will stop sand loss, reduce shore erosion and greatly upgrade its stability.
基金Under the auspices of National Natural Science Foundation of China(No.41530962)
文摘Coastal lagoons with small catchment basins are highly sensitive to natural processes and anthropogenic activities. To figure out the environmental changes of a coastal lagoon and its contribution to carbon burial, two sediment cores were collected in Xincun Lagoon, southeastern Hainan Island and (210) ~Pb activities, grain size parameters, total organic carbon(TOC), total nitrogen(TN), total inorganic carbon(TIC) and stable carbon isotopes(δ^(13)C) were measured. The results show that in 1770–1815, the decreasing water exchange capacity with outer open water, probably caused by the shifting and narrowing of the tidal inlet, not only diminished the currents and fined the sediments in the lagoon, but also reduced the organic matter of marine sources. From 1815 to 1950, the sedimentary environment of Xincun Lagoon was frequently influenced by storm events. These extreme events resulted in the high fluctuation of sediment grain size and sorting, as well as the great variation in contributions of terrestrial(higher plants, soils) and marine sources(phytoplankton, algae, seagrass). The extremely high content of TIC, compared to TOC before 1950 could be attributed to the large-scale coverage of coral reefs. However, with the boost of seawater aquaculture activities after 1970, the health growth of coral species was severely threatened, and corresponding production and inorganic carbon burial flux reduced. The apparent enhanced inorganic carbon burial rate after 1990 might result from the concomitant carbonate debris produced by seawater aquaculture. This result is important for local government long-term coastal management and environmental planning.
