南极阿德雷岛湖泊沉积210Pb、137Cs定年及其环境意义

测试了南极阿德雷岛两个湖泊 (Y2和G)沉积物的2 10 Pb和137Cs比度 .根据2 10 Pb和137Cs比度垂向变化特征 ,采用CRS模式对G湖进行了定年 ,年龄跨度大约为 134± 43年 ,并据此计算了G湖的沉积速率 .近大约 10 0年来G湖呈增长变化的沉积速率以及沉积物2 10 Pb ,137Cs蓄积量和沉降通量远大于大气直接沉降 ,可能是温度升高引起该地区大量冰雪 (盖 )融水携带补充的结果 .     

Magnetic minerals in Mid-Pleistocene sediments on the Caiwei Guyot,Northwest Pacific and their response to the Mid-Brunhes climate event

Seamounts are ubiquitous topographic units in global oceans, and their influences on local oceanic circulation have attracted great attention in physical oceanography; however, previous efforts were less made in paleoclimatology and paleoceanography. The Caiwei Guyot in the Magellan Seamounts of the western Pacific is a typical seamount, and in this study, we investigate a well-dated sediment core by magnetic properties to reveal the relationship between deep-sea sedimentary processes and global climate changes. The principal results are as follows: (1) the dominant magnetic minerals in the sediments are low-coercivity magnetite in pseudo-single domain range, probably including a biogenic contribution; (2) the variabilities of magnetic parameters can be clustered into two sections at ～500 ka, and the differences between the two units are evident in amplitudes and means; (3) changes in the grainsize-dependent magnetic parameters can be well correlated to records of global ice volume and atmospheric CO2 in the middle Pleistocene. Based on these results, a close linkage was proposed between deep-sea sedimentary processes in the Caiwei Guyot and global climate changes. This linkage likely involves different roles of biogenic magnetite in the sediments between interglacial and glacial intervals, responding to changes in marine productivity and deep-sea circulation and displaying a major change in the Mid-Brunhes climate event. Therefore, we proposed that the sedimentary archives at the bottom of the Caiwei Guyot record some key signals of global climate changes, providing a unique window to observe interactions between various environmental systems on glacial-interglacial timescales.     

改性当地土壤技术修复富营养化水体综合效果研究:Ⅱ.底栖动物群落结构和多样性的响应

从2010年10月开始在太湖梅梁湾围隔内实验区实施了改性当地土壤技术,在研究其对水体富营养化和蓝藻水华长效控制作用的同时,重点研究了底栖动物群落对此技术的响应.研究发现:经过11个月的处理,相比对照区,实验区内软体动物的平均密度和生物量分别增长了124%和33.8%,底栖动物Margalef和Shannon-Wiener多样性指数分别增长了41.1%和18.5%.环境因子和底栖动物群落的典范对应分析发现叶绿素a、温度、溶解氧和总磷对底栖动物群落有显著影响.本研究表明通过改性当地土壤技术降低水体营养盐含量和叶绿素a含量、增加底泥表层溶解氧含量,可以在一定程度上改善底栖动物生境,提高其物种多样性.     

对GML3.0应用模式的研究

阐述了GML3.0的主要模式,论述了GML应用模式开发的若干技术问题,并通过一个实例阐述了如何创建一个领域内的应用模式。     

基于PIES观测东沙群岛附近声传播变化

本研究旨在将PIES观测数据应用于海洋水声环境的监测。利用一次南海PIES观测数据,反演得到温盐剖面,进而计算声场信息。结合观测期间的暖涡及台风事件对反演及计算结果进行了分析验证。结果表明,PIES能够在长期连续观测中较为敏感地捕获上层水体及表面声道的变化特征,为水声通信、探测及潜航路径规划等提供参考,在水声研究及海洋军事环境保障中都具有良好的应用前景。     

福建云霄石榴子石宝石矿物学特征

福建云霄是我国重要的宝石级石榴子石产地,然而该区石榴子石的致色机理不清,制约了对其形成机制的理解及后续开发利用。本文选取7件福建云霄橙黄-橙红色石榴子石样品,利用傅立叶红外光谱、紫外-可见光光谱和拉曼光谱分析其谱学特征,使用电子探针及激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)分析限定其主量、微量元素组成。结果表明云霄石榴子石主要为锰铝榴石,其颜色主要与二价锰(Mn²⁺)和铁离子(Fe²⁺)对可见光的吸收有关,Mn²⁺导致其主体呈橙色,少量Fe²⁺控制其橙红色调,微量Ti⁴⁺使其呈褐色调。福建云霄石榴子石样品核部锰含量相对较低而铁、镁含量较高,锰元素含量由核部向边部逐渐升高,且具有重稀土元素富集、轻稀土元素亏损的左倾配分模式和Eu负异常,表明其形成于岩浆结晶作用晚期。     

常熟台倾斜仪降雨干扰定量分析

通过常熟地震台形变山洞内三套倾斜仪观测资料的对比分析,找到降雨、蓄水干扰对观测的影响,并利用弹性形变理论验证其可靠性,分析表明,每次强降雨均伴随有来自西南方向的倾斜干扰,其原因为雨水向湖中汇聚,水位上升产生弹性形变,从而引起地表倾斜.     

Effect of growth phase on the fatty acid compositions of four species of marine diatoms

The fatty acid compositions of four species of marine diatoms (Chaetoceros gracilis MACC/B13, Cylindrotheca fusiformis MACC/B211, Phaeodactylum tricornutum MACC/B221 and Nitzschia closterium MACC/B222), cultivated at 22 ℃±1 ℃ with the salinity of 28 in f/2 medium and harvested in the exponential growth phase, the early stationary phase and the late stationary phase, were determined. The results showed that growth phase has significant effect on most fatty acid contents in the four species of marine diatoms. The proportions of 16:0 and 16: 1n-7 fatty acids increased while those of 16 :3n-4 and eicosapentaenoic acid (EPA) decreased with increasing culture age in all species studied. The subtotal of saturated fatty acids (SFA) increased with the increasing culture age in all species with the exception of B13. The subtotal of monounsaturated fatty acids (MUFA) increased while that of polyunsaturated fatty acids (PUFA) decreased with culture age in the four species of marine diatoms. MUFA reached their lowest value in the exponential growth phase, whereas PUFA reached their highest value in the same phase.     

青藏高原地表热源异常与四川盆地夏季降水的关联

利用所计算的1961—1995年高原热源资料、四川与重庆的降水资料以及500hPa月平均高度场资料，分析了高原地表热源异常对四川盆地降水与旱涝的影响。结果表明，高原地表热源异常与四川盆地降水和旱涝有显著的相关；高原地表热源异常通过强迫500hPa东亚大气环流异常来影响四川盆地降水。     

东北冷涡的多普勒雷达资料特征分析

多普勒雷达探测东北冷涡具有一定的径向速度特征;应用蓝金(Rankine)模式进行数值模拟,结果表明,其模拟的多普勒速度分布特征与多普勒雷达实际探测冷涡的特征极其相似;根据多普勒径向速度特征确定冷涡中心,进而应用不同时刻资料确定冷涡的移动路径,对实际业务有很好的应用价值。