南海高钙沉积物中18种常微量元素的ICP-AES测定方法研究

在利用ICP-AES分析南海高钙沉积物中的常微量元素时,钙、镁常常干扰其它元素测试。通过采用优化仪器工作参数、扣除背景值、谱线干扰校正和基体匹配的步骤,消除了元素干扰和钙、镁基体效应,提高了方法的灵敏度和准确度。通过对南海沉积物样品的大量实验和国家一级标准样验证,建立了适宜高钙海洋沉积物元素含量的ICP-AES测试方法。该方法检出限为1.55~271μg/L,相对标准偏差RSD<4.54%(n=6)。     

新疆福海第一农场水库浮游植物生态初步研究

于2008年7月(平水期)、10月(枯水期)和次年5月(丰水期)对新疆阿勒泰地区福海县第一农场水库浮游植物进行了生态学调查.共采集到浮游植物8门75种(属),其中绿藻28种、硅藻21种、蓝藻13种、裸藻6种、黄藻2种、甲藻2种、隐藻2种和金藻1种,绿藻和硅藻在种类组成上占明显优势.各期优势种不尽相同:平水期优势种为类颤...     

东天山觉罗塔格构造带钙碱性侵入岩角闪石矿物学特征及其对区域找矿的启示

新疆东天山觉罗塔格构造带位于吐哈盆地和中天山地块之间,区内矿产资源丰富,是我国重要的金属矿产分布区,其成矿作用与岩浆活动密切相关.本文在详细岩相学观察的基础上,对角闪石进行了电子探针(EMPA)测试分析,限定了区内8个岩体结晶的温压条件、岩浆氧逸度和含水量等要素,为解析觉罗塔格构造带内钙碱性侵入岩的构造环境、演化过程和...     

基于时序遥感的庐山自然保护区植被分类及其变化分析

自然保护区是生物多样性最丰富的区域,针对近年来庐山自然保护区森林生物多样性进行调查,了解保护区内植被的分布及其变化,对于保护庐山境内的林业资源具有重要的意义.论文利用2015-2018年Proba-Ⅴ卫星100m分辨率5d植被指数产品,使用最大值合成法、Hants时间序列谐波分析方法对数据进行平滑降噪处理,并采用随机森...     

2007年宁洱6.4级地震余震序列尾波QC值研究

基于Aki和Chouet的地方震尾波单次散射模型,利用思茅台记录到的2007年云南宁洱6.4地震余震的数字化波形观测资料,测量了震源区尾波Qc(f)值。当中心频率为1.5Hz时,宁洱地区的尾波Qc值在51～147之间,平均值为79,尾波的振幅衰减率βc(f)在0.014～0.039之间,平均值为0.028;测量得到该地区尾波Qc值与频率f的关系为Qc(f)=53f0.88;尾波波源因子与震级成正比关系,满足关系lgA0=1.51ML-0.94;测量结果显示宁洱地震余震序列的尾波值Qc较低,表明宁洱震源区属于构造运动较为活跃区。     

末次冰期东亚季风快速波动的模式与成因

通过对位于东亚季风区中东部与西部边缘的两个高分辨率黄土剖面记录的对比研究，发现它们不仅捕捉到了20个Dansgaard Oeschger事件与6个Heinrich事件，而且黄土记录与GRIP冰芯记录的这些快速气候波动基本上是同步的。暗示在整个末次冰期，东亚季风气候同样存在千年—百年尺度上的快速波动。所不同的是，西面的沙沟剖面对这些快速气候波动的反应比东面的王官剖面敏感。结合末次冰期中国黄土记录的先前研究结果，我们发现，自西向东Dansgaard Oeschger旋回的幅度逐渐变小，推测这主要是由西风与东亚夏季风共同作用所造成的。     

用NCEP／NCAR再分析辐射资料估算月平均地表反照率

本文利用１９７９年￣１９９５年１７年平均的ＮＣＥＰ／ＮＣＡＲ（Ｎａｔｉｏｎａｌ Ｃｅｎｔｅｒ ｆｏｒ Ｅｎｖｉｒｏｎｍｅｎ－ｔａｌ Ｐｒｅｄｉｃｔｉｏｎ／Ｎａｔｉｏｎａｌ Ｃｅｎｔｅｒ ｆｏｒ Ａｔｍｏｓｐｈｅｒｉｃ Ｒｅｓｅａｒｃｈ,美国国家环境预报中心／美国国家大气研究中心）再分析辐射资料估算了全球月平均地表反照率．从所得结果的时空分布来看,用ＮＣＥＰ／ＮＣＡＲ辐射资料得到的全球地表反照率基本     

New density measurements on carbonate liquids and the partial molar volume of the CaCO<Subscript>3</Subscript> component

Density measurements on nine liquids in the CaCO₃–Li₂CO₃–Na₂CO₃–K₂CO₃ quaternary system were performed at 1 bar between 555 and 969 °C using the double-bob Archimedean method. Our density data on the end-member alkali carbonate liquids are in excellent agreement with the NIST standards compiled by Janz (1992). The results were fitted to a volume equation that is linear in composition and temperature; this model recovers the measured volumes within experimental error (±0.18% on average, with a maximum residual of ±0.50%). Our results indicate that the density of the CaCO₃ component in natrocarbonate liquids is 2.502 (±0.014) g/cm³ at 800 °C and 1 bar, which is within the range of silicate melts; its coefficient of thermal expansion is 1.8 (±0.5)×10^–4 K^–1 at 800 °C. Although the volumes of carbonate liquids mix linearly with respect to carbonate components, they do not mix linearly with silicate liquids. Our data are used with those in the literature to estimate the value of in alkaline silicate magmas (20 cm³/mol at 1400 °C and 20 kbar), where CO₂ is dissolved as carbonate in close association with Ca. Our volume measurements are combined with sound speed data in the literature to derive the compressibility of the end-member liquids Li₂CO₃, Na₂CO₃, and K₂CO₃. These results are combined with calorimetric data to calculate the fusion curves for Li₂CO₃, Na₂CO₃, and K₂CO₃ to 5 kbar; the calculations are in excellent agreement with experimental determinations of the respective melting reactions.Editorial responsibility: I Carmichael     

Changes in the patterns of inorganic nitrogen and TN/TP ratio and the associated mechanism of biological regulation in the shallow lakes of the middle and lower reaches of the Yangtze River

The changes of NH₃-N, NO₃-N, NO₂-N and TN/TP were studied during growth and non-growth season in 33 subtropical shallow lakes in the middle and lower reaches of the Yangtze River. There were significant positive correlations among all nutrient concentrations, and the correlations were better in growth season than in non-growth season. When TP>0.1 mgL^?1, NH₃-N increased sharply in non-growth season with increasing TP, and NO₃-N increased in growth season but decreased in non-growth season with TP. These might be attributed to lower dissolved oxygen and low temperature in non-growth season of the hypereutrophic lakes, since nitrification is more sensitive to dissolved oxygen and temperature than antinitrification. When 0.1 mgL^?1>TP>0.035 mgL^?1, TN and all kinds of inorganic nitrogen were lower in growth season than in non-growth season, and phytoplankton might be the vital regulating factor. When TP<0.035 mgL^?1, inorganic nitrogen concentrations were relatively low and NH₃-N, NO₂-N had significant correlations with phytoplankton, indicating that NH₃-N and NO₂-N might be limiting factors to phytoplankton. In addition, TN/TP went down with decline in TP concentration, and TN and inorganic nitrogen concentrations were obviously lower in growth season than in non-growth season, suggesting that decreasing nitrogen (especially NH₃-N and NO₃-N) was an important reason for the decreasing TN/TP in growth season. The ranges of TN/TP were closely related to trophic level in both growth and non-growth seasons, and it is apparent that in the eutrophic and hypertrophic state the TN/TP ratio was obviously lower in growth season than in non-growth season. The changes of the TN/TP ratio were closely correlated with trophic levels, and both declines of TN in the water column and TP release from the sediment were important factors for the decline of the TN/TP ratio in growth season.     

月球地图投影理论和方法研究

以我国的探月计划为出发点,在以球面作为月球数学表面的前提下,研究3种不同投影理论和方法在绘制月面图中的应用。讨论基于月面的等角横切圆柱投影、等角正割圆锥投影和外心透视投影的性质及变形规律。经过理论研究和计算,分别提出用等角横切圆柱投影、等角正割圆锥投影来做月面图的分带方案。通过比较3种投影变形,建议月面图两极10°范围内采用外心透视投影,北纬80°~南纬80°之间采用等角正割圆锥投影,以带宽10°自月球赤道分别向南北分带,南北半球各分为8个带。