Total organic carbon fluxes of the Red River system (Vietnam)

Riverine transport of organic carbon from terrestrial ecosystems to the oceans plays an important role in the global carbon cycle. The Red River is located in Southeast Asia where river discharge, sediment loads and fluxes of elements (carbon, nitrogen and phosphorus) associated with suspended solids have been dramatically altered over past decades as a result of reservoir impoundment and land use, population, and climate change. Dissolved organic carbon (DOC) and particulate organic carbon (POC) concentrations were measured monthly at four stations of the Red River system from January 2008 to December 2010. The results reveal that POC changed synchronically with total suspended solids (TSS) concentration and with the river discharge, whereas no clear trend was observed for DOC concentration. The mean value of total organic carbon (TOC = DOC + POC) flux in the delta of the Red River was 31.5 × 10¹³ ± 4.0 × 10¹³ MgC.yr^?1 (range 27.9–35.8 × 10¹³ MgC.yr^?1 which leads to a specific TOC flux of 2012 ± 255 kgC.km^?2.yr^?1 during this 2008–2010 period. About 80% of the TOC flux was transferred to the estuary during the rainy season as a consequence of the higher river water discharge. The high mean value of the POC:Chl‐a ratio (1585 ± 870 mgC.mgChl‐a^?1) and the moderate C:N ratio (7.3 ± 0.1) in the water column system suggest that organic carbon in the Red River system is mainly derived from erosion and soil leaching in the basin. The effect of two new dam impoundments in the Red River was also observable with lower TOC fluxes in 2010 compared with 2008. Copyright © 2017 John Wiley & Sons, Ltd.     

南极普里兹湾柱样有孔虫研究

南极普里兹湾柱样ＮＰ９３２含有较多的有孔虫，其中浮游类占２６．３％，底栖类中砂质胶结类占５７．９％，为该柱的优势类群。底栖有孔虫组合以Ｍｉｌｉａｍｍｉｎａａｒｅｎａｃｅａ为典型代表，显示了深水砂质胶结相的面貌。浮游类群中暖与冷水种群的丰度变化，反映了所在海区气温的变化     

Application of the radial basis function neural network to the short term prediction of the Earth’s polar motion

By a number of test cases using different sample numbers and sample lengths, we obtain a Radial Basis Function Neural Network (RBFNN) model that is suitable for the short-term forecast of polar motion, especially for the ultra-short-term forecast. By using the same data sample of Earth’s polar motion, this RBFNN model can achieve better short-term prediction accuracy than the least-squares+autoregressive (LS+AR) method, and better ultra-short-term prediction accuracy than the LS+AR+Kalman method. Using this model to forecast the polar motion data from January 1, 2002 to December 30, 2007 and from January 1, 2010 to December 30, 2016, respectively, experimental results show that the ultra-short-term forecast accuracy of this RBFNN model is within a precision of 3.15 and 3.08 milliseconds of arc (mas) in polar motion x direction, 2.02 and 2.04 mas in polar motion y direction; the short-term forecast accuracy of RBFNN model is within a precision of 8.83 and 8.69 mas in polar motion x direction, and 5.59 and 5.85 mas in polar motion y direction. As is stated above, this RBFNN model is well capable of forecasting the short-term of polar motion, especially the ultra-short-term.     

广西新寨矿泉水出露特征及形成机理

新寨矿泉水属重碳酸钙钠型低钠、低矿化度的含氯硅酸矿泉水，是来自花岗岩体中较深层的构造裂隙水、其水质、水量、水温十分稳定，为花岗岩体中较深层的构造裂隙水。矿泉水中有益元素的物质组份来源于花岗岩体，偏硅酸和氡含量达到国家标准，具有经济价值。     

东欢坨矿8煤瓦斯异常的地质因素

运用压汞法和等温吸附法对开滦矿区东欢坨矿8煤储层特征进行研究,结合矿井实测瓦斯涌出量数据,分析了控制东欢坨矿8煤瓦斯异常涌出的地质因素。结果表明:瓦斯异常主控地质因素为地质构造及水文地质特征,东欢坨矿\     

Uncertainty and variability in bivariate modeling of hydrological droughts

There are two kinds of uncertainty factors in modeling the bivariate distribution of hydrological droughts: the alteration of predefined critical ratios for pooling droughts and excluding minor droughts and the temporal variability of univariate and/or bivariate characteristics of droughts due to the impact of human activities. Daily flow data covering a period of 56 hydrological years from two gauging stations from a humid region in South China are used. The influences of alterations of threshold values of flow and critical ratios of pooling droughts and excluding minor droughts on drought properties are analyzed. Six conventional univariate models and three Archimedean copulas are employed to fit the marginal and joint distributions of drought properties, the Kolmogorov–Smirnov and Anderson–Darling methods are used for testing the goodness-of-fit of the univariate model, and the Cramer-von Mises method based on Rosenblatt’s transform is applied for the test of the bivariate model. The change point analysis of the copula parameter of bivariate distribution of droughts is first made. Results demonstrate that both the statistical characteristics of each drought property and their bivariate joint distributions are sensitive to the critical ratio of excluding minor droughts. A model can be selected to fit the marginal distribution for drought deficit volume or maximum deficit, but it is not determined for drought duration with the lower ratios of the pooling and excluding droughts. The statistical uncertainty of drought duration makes the modeling of bivariate joint distribution of drought duration and deficit volume or of drought duration and maximum deficit undermined. Change points significantly occurred in the period from the late 1970s to the middle 1980s for a single drought property and the copula parameter of their joint distribution due to the impact of human activities. The difference between two subseries separated by the change point is remarkable in the magnitudes of drought properties and the joint return periods. A copula function can be selected to optimally fit the bivariate distribution, provided that the critical ratios of pooling and excluding droughts are great enough such as the optimal value of 0.4 in the case study. It is valuable that the modeling and designing of the bivariate joint correlation and distribution of drought properties can be performed on the subseries separated by the change point of the copula parameter.     

Quantification of Water Content and Speciation in Synthetic Rhyolitic Glasses: Optimising the Analytical Method of Confocal Raman Spectrometry

Quantification of water content in silicate glasses is of vital significance in understanding magma evolution and metamorphic anataxis. Here we provide a method for the determination of total dissolved water content and water speciation in silicate melts by confocal laser Raman spectrometry based on a set of hydrous rhyolitic glasses. A series of alumino-silicate glasses with water contents from 0.33 to 9.05% m/m were synthesised in a piston cylinder apparatus. Synchrotron-FTIR mapping shows that these glasses have relatively homogeneous distributions of dissolved water. Total water contents of the glasses were precisely measured by TC/EA-MS and FTIR. Both external and internal calibration were established for the quantitative analysis of water content and water speciation in the silicate glasses based on excellent linear correlation between total dissolved water content and integrated area of the water Raman band. Furthermore, by decomposing the total water Raman bands into four Gaussians components, the relative concentration of water speciation (OH groups and molecules H₂O_m) dissolved in the glasses was determined with a similar trend to water speciation data derived from FTIR. We suggest that the relative concentration of water speciation can be estimated in rhyolitic glasses with 4–8% m/m H₂O. Our work provides an accurate method to determine total water content and a potential tool to limit the relative concentration of water speciation dissolved in silicic glasses.     

气象预报服务效益评估方法研究——以暴雨预报服务为例

暴雨是江苏的重要气象灾害之一,为了对暴雨预报气象服务效益作出恰当的评估,我们设计了预报准确率V、预报服务覆盖率P、预报服务时效率N、可能预防能力Z等四个指标,给出了定量评估暴雨预报气象服务效益的数学模型,并且用实例说明了该模型的实用性和可操作性.预报服务覆盖率、预报服务时效和预报准确率与服务效益成正比,各个因子都会很大程度上影响服务效益值.预防能力越强,气象服务的效益越大,这也说明了气象预报只是一种信息,信息价值的体现还在于应用信息群体的决策和防御能力.     

中国基本公共气象服务均等化水平现状——基于多层次灰色关联的实证研究

参考相关文献界定基本气象公共服务均等化内涵,并设计基本公共气象服务均等化水平多层次评价指标体系,对2013年的统计数据整理归纳出10个指标,用因子分析分成3类;由层次分析法构建层次结构关系图,通过专家咨询得出判断矩阵,依据判断矩阵定量计算出准则层和指标层中各因素的相对权重,然后对2013年全国31个省域基本公共气象服务均等化水平应用灰色关联综合评价模型进行实证分析。结果表明:基本公共气象服务均等化水平由西向东阶梯状递增、省域之间差异较大、总体水平偏低;大致可以分成较高、一般、较低3个区域等级;与省域经济、财政收入、综合发展能力正相关。     

A New Lithostratigraphic Framework for the Cretaceous Colorado Group in the Cold Lake Heavy Oil Area,East-Central Alberta,Canada

The Albian to Santonian Colorado Group in the heavy oil area of Cold Lake, east-central Alberta represents a relatively condensed section of shale-dominated sedimentation within the Western Interior Sea. These shales form the cap rock to the underlying Clearwater and Grand Rapids formations that are exploited for bitumen extraction. Two cores covering the entire Colorado Group provide a unique opportunity for establishment of a stratigraphic reference in an area that has received attention only for its heavy oil-bearing Mannville Group. Based on sedimentology, geochemistry, micropaleontology, nannofossils, and wireline log data, the Colorado Group was subdivided into the Joli Fou, Viking, Westgate, Fish Scales, Belle Fourche, Second White Specks, and Niobrara formations. The Niobrara Formation was subdivided further into the Verger Member, informal Cold Lake member, and First White Specks Member. Because of this region’s small accommodation space and distance to sources of coarse clastic sediment, disconformities are indicated lithologically by bioclastic layers and missing biozones. Foraminiferal subzones revealed two erosional boundaries associated with the Viking Formation. Faunal and floral evidence coupled with wireline log correlations suggest that the Middle to Upper Turonian Carlile Formation, as described from southeastern Alberta, is missing. That extends the Middle Turonian to Coniacian unconformity, as recognized in central Saskatchewan, westwards into Alberta.