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运用平面二维数值模拟的方法,在长乐海上风电场B区建成之后对海域的影响进行了研究,将风电桩基概化为边长为6. 4 m的正六边形,采用网格嵌套、逐层加密的方式对研究区地形进行刻画,模型经过6个测点和1个临时潮位站实测资料的验证,表明模型结果良好,能够反映研究区潮流性质,并模拟风电场建成后对所在海域和风电桩基附近的影响。模型计算结果表明,风电场建成后对所在海域的主要影响集中在桩基附近,对流场影响主要体现在流速的变化上,在桩基根部附近,流速会因为桩基之间的束水效应增大;在桩基周围因为其阻水效应,桩基背水面和迎水面流速均会减小,且背水面流速变化范围会大于迎水面。工程会对北部两排桩基周围的余流产生10%左右的影响,产生30%数值变化的范围仅在桩基根部。 相似文献
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在用离子色谱法测定温泉水样中F~-、Cl~-、Br~-、NO_2~-、NO_3~-、SO_4~(2-)、PO_4~(2-)等阴离子和Li~+、Na~+、K~+、Mg~(2+)、Ca~(2+)等阳离子过程中,研究了用油泵超声波池内脱气法处理H_2CO_3过饱和水样以排除HCO_3~-对阴离子检测干扰的方法.研究采用青岛普仁仪器有限公司生产的PIC-8型离子色谱仪,分离柱为TSK-GEL SuperIC-CationColumn(150 mm×4.5 mm)离子分离柱,以1.9 mmol/L碳酸钠-1.8mmol/L碳酸氢钠作为阴离子淋洗液,流量为1.5 Ml/min;以2 mmol/L HNO_3为阳离子淋洗液,流量为1.0 ml/min,测定了腾冲火山区叠水河、大滚锅两个温泉水中的阴阳离子的含量.研究结果表明:该方法简便、快速、准确可靠,可在火山和地震监测中推广使用. 相似文献
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广西钦州湾晚全新世红树林演变及对海平面变化的响应 总被引:2,自引:0,他引:2
Mangroves, widely distributed along the coasts of tropical China, are influenced by Asia monsoon, relative sea level change and enhanced human activity. To predict the impacts of future climate change on mangrove ecosystems, it can be understood by reconstructing past mangrove dynamics using proxies preserved in coastal sediments. In this study, we quantitatively partitioned buried organic matter(OM) sources, collected from a vulnerable mangrove swamp in the Qinzhou Bay of northwestern South China Sea, using a ternary end-member mixing model of δ~(13)C and C:N values. Mangrove-derived OM(MOM) contribution was used as a tracer for mangrove development since 2.34 cal ka BP. This information, together with paleoclimate records(i.e.,speleothem δ~(18)O values, sea level change, grain size parameters) and human activity, was used to divide mangrove development into three stages during the late Holocene: relative flourish(2.34–1.13 cal ka BP), relative degradation(1.13–0.15 cal ka BP) and further degradation(0.15–0 cal ka BP). Before 1.13 cal ka BP, mangroves flourished with a high MOM contribution((88.9±10.6)%), corresponding to stable and high sea level under a warm and humid climate. After 1.13 cal ka BP, rapid fall in relative sea level coupled with the strengthening of the Asian winter monsoon, resulted in mangrove degradation and MOM reduction((62.4±18.9)%). Compared with air temperature and precipitation, the relative sea level fall was the main controlling factor in mangrove development before entering the Anthropocene(the time of the Industrial Revolution). After ~150 cal a BP, reclamation of mangrove swamps to shrimp ponds is the main factor causing mangrove degradation and MOM reduction. 相似文献