Distribution of plant species and species-soil relationship in the east central Gurbantunggut Desert,China   总被引：1，自引：0，他引：1  

AN Ping  LI Xiangjun  ZHENG Yuanrun  ENEJI A. Egrinya  QIMAN Yunus  ZHENG Mingqing  INANAGA Shinobu 《地理学报》2015,25(1):101-112

The distribution of plant species and relationships between species and soil factors in the east central part of Gurbantunggut Desert was studied to provide more insight into the flora and determine differences in vegetation across various parts of the desert. Two-way Cluster Analysis showed that the vegetation in the area could be divided into three groups, the first group was dominated by the shrub species, Ephedra przewalskii and the grass species, Carex physodes mainly in areas of flat grounds and gentle slopes; the second group was dominated by C. physodes, Artemisia songorica and A. xerophytica mainly on the slope of sand dunes and the third group was dominated by the shrub species, Haloxylon persicum mainly on the top of sand dunes. There was no difference in plant density between Groups 1 and 2 but there was a significant decrease in Group 3. Soil water under vegetation Group 3 was much lower than that in the other two groups at all soil depths. The EC, organic matter, total P and soluble Na, Ca and Mg varied very similarly with soil water. Canonical correspondence analysis (CCA) satisfactorily assessed the species-soil relations in the area. The distribution of plant species was strongly correlated with the soil factors of water content, organic matter, EC and nutrients. The variations in species occurrence explained by the three CCA axes were about 70%, indicating that some explanatory site variables may exist outside our studied parameters. Soil texture is suggested to be included in future studies to improve the explanation of CCA.  相似文献   

南宁市霾的特征分析     

莫雨淳  廖国莲  郑凤琴 《气象研究与应用》2015,36(1)

利用1993年至2012年南宁市观测站资料,分析了南宁市近20年霾的变化特征。结果表明:从2000年以来南宁霾日数上涨明显。霾的出现有明显的季节变化,冬季在冷锋经过后气温下降、地面被冷高压控制,风速减小,近地层形成逆温时出现;夏季主要在热带低压外围的下沉气流影响下出现。南宁市出现的霾绝大部分为轻度霾(能见度在3km至10km),并且发生霾天气时,相对湿度六成以上介于70%~80%之间。  相似文献   

3D Direct Simulation Monte Carlo Modelling of the Inner Gas Coma of Comet 67P/Churyumov–Gerasimenko: A Parameter Study     

Y. Liao  C. C. Su  R. Marschall  J. S. Wu  M. Rubin  I. L. Lai  W. H. Ip  H. U. Keller  J. Knollenberg  E. Kührt  Y. V. Skorov  N. Thomas 《Earth, Moon, and Planets》2016,117(1):41-64

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Isotopic composition of dissolved boron and its geochemical behavior in a freshwater-seawater mixture at the estuary of the Changjiang （Yangtze） River     

肖应凯  廖步勇  王中良  魏海珍  赵志琦 《中国地球化学学报》2007,26(2):105-113

The isotopic composition of dissolved boron, in combination with the elemental concentrations of B, Cl and salinities in freshwater-seawater mixed samples taken from the estuary of the Changjiang River, the largest one in China, was investigated in detail in this study. Brackish water and seawater samples from the estuary of the Changjiang River were collected during low water season in November, 1998. Boron isotopic compositions were determined by the Cs2BO^＋2-graphite technique with a analytical uncertainty of 0.2‰ for NIST SRM 951 and an average analytical uncertainty of 0.8‰ for the samples. The isotopic compositions of boron, expressed in δ^11B, and boron concentrations in the Changjiang River at Nanjing and seawater from the open marine East Sea, China, are characterized by δ^11B values of -5.4‰ and 40.0‰, as well as 0.0272 and 4.43 mg B/L, respectively. Well-defined correlations between δ^11B values, B concentrations and Cl concentrations are interpreted in terms of binary mixing between fiver input water and East Sea seawater by a process of straightforward dilution. The offsets of δ^11B values are not related to the contents of clastic sediment and to the addition of boron. These relationships favor a conservative behavior of boron at the estuarine of the Changjiang River.  相似文献   

0414号台风“云娜”的数值模拟   总被引：20，自引：3，他引：17  

余贞寿  廖胜石  黄克慧  叶子祥  赵放 《气象学报》2005,63(6):903-914

利用美国CAPS的非静力高分辨率区域预报模式(ARPS)对0414号台风"云娜"进行数值模拟,其中把新一代多普勒天气雷达资料分析引入模式,模拟结果表明ARPS模式能较好模拟台风"云娜"的移动路径、中心气压强度变化及台风大暴雨;并利用模式输出的组合反射率与雷达组合反射率资料比较来检验模拟结果.数值模拟结果表明台风自身结构是引起0414号台风西折路径的重要原因;浙南闽北地形对0414号台风的影响作地形敏感性试验结果表明浙南闽北地形使0414号台风移动路径出现右偏现象;浙南闽北地形对0414号台风强度影响较小,地形对深入内陆后台风强度变化有较明显的影响;浙南闽北地形对0414号台风暴雨有增幅作用,降水分布更加不均匀.  相似文献   

Characterization of land subsidence in the Choshui River alluvial fan,Taiwan   总被引：4，自引：3，他引：1  

Chih-Hsi?LiuEmail author  Yii-Wen?Pan  Jyh-Jong?Liao  Chen-Tair?Huang  Shoung?Ouyang 《Environmental Geology》2004,45(8):1154-1166

Land subsidence in Taiwan has increased rapidly over the past four decades, owing to heavy withdrawal of groundwater. Leveling surveys, layer compressions and groundwater level in individual layers were continuously monitored in the Choshui alluvial fan, western Taiwan. It was found that ground subsidence and layer compression were consistent with the variation of groundwater level. From multi-level compression monitoring, the layers with major compression deformation were identified. Clayey and sandy layers exhibited significant compression deformation. Conceptual models of compression behavior for clays and sands were studied based on the field data. The compression behavior of clays agreed with the Terzaghi consolidation theory. Notable, irrecoverable volumetric strains were also observed in sandy layers. They exhibited obvious elasto-plastic mechanical behavior. The high compressibility of the sand layer in the alluvial fan was attributed to the flaky sand grains in this geological region.  相似文献   

南极半岛西北部海域蛇尾类研究     

廖玉麟  孙松  陈国通 《海洋科学集刊》1991,(32):325-354

1984-1985年，我国首次对南极进行科学考察时在南极半岛西北部海域，南设得兰岛附近进行底栖生物的定性和定量采集，获得很多蛇尾类标本，根据作者研究，共计30种，其中有8种在该区域是新记录。  相似文献   

台湾海峡西部海域沉积物中重金属的地球化学特征   总被引：3，自引：3，他引：3  

陈松  许爱玉 《台湾海峡》1993,12(3):280-286

台湾海峡西部海域表层沉积物中重金属含量与未污染近岸沉积物的平均含量相当,基本上未受污染。各重金属含量具有沿东北至西南方向递减的分布趋势。沉积物中微量金属的含量明显地受Fe-Mn 氧化物和有机质的含量所控制。福建沿海主要港湾沉积物中Pb、Zn 含量偏高,微量金属含量不受Fe-Mn 氧化物和有机质控制,构成本地区沉积物的两种区域性特征。  相似文献   

东太平洋海盆海山玄武岩特征   总被引：1，自引：0，他引：1  

康长生  梁德华  廖志良 《海洋地质与第四纪地质》1997,(2)

东太平洋海山玄武岩属于大洋岛屿拉斑玄武岩，主要由橄榄拉斑玄武岩、石英拉斑玄武岩和橄榄玄武岩组成，具有拉斑玄武岩系列和过渡玄武岩系列。岩石具有基质为拉斑玄武结构或间隐结构的斑状结构和气孔构造，斑晶主要由拉长石和普通辉石组成，基质除拉长石和玻璃质外，还有少量普通辉石和磁铁矿等，岩石化学成分中Ａｌ２Ｏ３、Ｎａ２Ｏ、Ｋ２Ｏ含量偏高。玄武岩中稀土元素分配型式基本相同，曲线较平坦，稀土分馏不明显，具Ｃｅ、Ｅｕ负异常，反映岩石具有共同的成因，属晚白垩世以来的产物  相似文献   

厦门西港表层沉积物的化学特征   总被引：11，自引：3，他引：11  

陈松  廖文卓 《台湾海峡》1992,11(2):131-137

本文根据1990年厦门西港重要站点的表层沉积物中的重金属(Fe、Mn、Cu、Pb、Zn、Cd、Hg)、有机污染物(总有机碳、石油、DDT、666)和磷(无机磷、有机磷和总磷)等测定资料,讨论了它们的地球化学性质及环境影响。结果表明,沉积物中Pb和Zn含量明显偏高,Pb、cu含量与1983年相比已有一定积累,也产生了有机污染现象。  相似文献