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961.
962.
<正> 苏联领土面积为22.4百万平方公里,占世界大陆总面积的六分之一。苏联拥有多种大型地质构造,如古老的东欧地台和西伯利亚地台及波罗的、乌克兰、阿尔丹和阿纳巴尔地盾,还包括显生宙的乌拉尔-蒙古、地中海和太平洋褶皱带(图1)的广阔区 相似文献
963.
Shouliang Huo Jingtian Zhang Kevin M. Yeager Beidou Xi Yanwen Qin Zhuoshi He Fengchang Wu 《环境科学学报(英文版)》2023,31(5):1-11
The technique of DGT (diffusive gradients in thin films) using three diffusive gel thicknesses was applied to estimate the mobility and bioavailability of heavy metals in sediments and porewater of Lake Taihu, China. The DGT results showed significantly positive correlations between Co, Pb, Cd and Mn, and Ni and Fe concentrations in porewater. Cu and Zn showed a significantly negative correlation with Mn, due to Cu combination with carbonates and Zn derived from agricultural pollution, respectively. The rank order of average concentrations of Co, Ni and Cd at each station was DGT1.92 > DGT0.78 > DGT0.39, suggesting stronger resupply from sediments to porewater when using thicker diffusive gels. Comparing centrifugation and DGT measurements, Co, Ni and Cd are highly labile; Mn and Fe are moderately labile; and Cu, Zn and Pb are slightly labile. The variations of AVS concentrations in sediment cores indicate that metal sulfides in deeper layers are easily diffused into surface sediments. 相似文献
964.
介绍了气体测量法在厚层沉积物覆盖区普查隐伏金属矿床、矿化水和金伯利岩筒等方面的应用。该方法的实质就是通过沿钻孔网测定地下大气中气体指示组分的含量,以查明叠加的次生分散晕。以高加索等地区的研究为例,证明了该法可追索控矿构造、可有效地图出隐伏矿化和矿化水远景区,并可降低普查费用。 相似文献
965.
<正> 萤石是一种最重要的矿产,离开它冶金工业、化学工业以及其它许多工业部门都不能顺利地发展。虽然近十年来世界上萤石的开采和消费的数量有所下降,但是至今仍是相当大的——每年约450万吨。萤石的主要消费者是苏联、美国、日本和联邦德国,而且萤石的消费在苏联正逐渐增长。所以,对苏联来说,扩大 相似文献
966.
<正> 一、引言部分熔融问题的研究,基本上有两种主要方法:(1)对于同位素均一的每种岩浆系列,可以用熔岩成分来计算原始液相的成分,进而模拟熔融过程;(2)通过研究熔融残余相的野外构造特征及其化学成分,有可能获得部分熔融过程中小规模作用的直接信息。 相似文献
967.
968.
<正> 目前,许多研究者通过对变质黑色片岩层中金矿床的研究得出了这样的结论,即金矿床是由原始沉积岩变质而成的。这一点已为下述事实所证实:这些黑色片岩中的金矿床主要产于变质程度达绿片岩相(据А.А.Маракушев资料,从泥质片岩相到云母片岩相)的变泥岩 相似文献
969.
Could wastewater analysis be a useful tool for China? — A review 总被引:1,自引:0,他引:1
Jianfa Gao Jake O''Brien Foon Yin Lai Alexander L.N. van Nuijs Jun He Jochen F. Mueller Jingsha Xu Phong K. Thai 《环境科学学报(英文版)》2015
Analysingwastewater samples is an innovative approach that overcomesmany limitations of traditional surveys to identify and measure a range of chemicals that were consumed by or exposed to people living in a sewer catchment area. First conceptualised in 2001, much progress has been made to make wastewater analysis (WWA) a reliable and robust tool for measuring chemical consumption and/or exposure. At the moment, the most popular application of WWA, sometimes referred as sewage epidemiology, is to monitor the consumption of illicit drugs in communities around the globe, including China. The approach has been largely adopted by lawenforcement agencies as a device tomonitor the temporal and geographical patterns of drug consumption. In the future, themethodology can be extended to other chemicals including biomarkers of population health (e.g. environmental or oxidative stress biomarkers, lifestyle indicators or medications that are taken by different demographic groups) and pollutants that people are exposed to (e.g. polycyclic aromatic hydrocarbons, perfluorinated chemicals, and toxic pesticides). The extension of WWA to a huge range of chemicals may give rise to a field called sewage chemical-information mining (SCIM) with unexplored potentials. China has many densely populated cities with thousands of sewage treatment plants which are favourable for applying WWA/SCIM in order to help relevant authorities gather information about illicit drug consumption and population health status. However, there are some prerequisites and uncertainties of the methodology that should be addressed for SCIM to reach its full potential in China. 相似文献
970.
Surface water methane (CH4) and nitrous oxide (N2O) concentrations and fluxes were investigated in two subtropical coastal embayments (Bramble Bay and Deception Bay, which are part of the greater Moreton Bay, Australia). Measurements were done at 23 stations in seven campaigns covering different seasons during 2010-2012. Water-air fluxes were estimated using the Thin Boundary Layer approach with a combination of wind and currents-based models for the estimation of the gas transfer velocities. The two bays were strong sources of both CH4 and N2O with no significant differences in the degree of saturation of both gases between them during all measurement campaigns. Both CH4 and N2O concentrations had strong temporal but minimal spatial variability in both bays. During the seven seasons, CH4 varied between 500% and 4000% saturation while N2O varied between 128 and 255% in the two bays. Average seasonal CH4 fluxes for the two bays varied between 0.5 ± 0.2 and 6.0 ± 1.5 mg CH4/(m2·day) while N2O varied between 0.4 ± 0.1 and 1.6 ± 0.6 mg N2O/(m2·day). Weighted emissions (t CO2-e) were 63%-90% N2O dominated implying that a reduction in N2O inputs and/or nitrogen availability in the bays may significantly reduce the bays' greenhouse gas (GHG) budget. Emissions data for tropical and subtropical systems is still scarce. This work found subtropical bays to be significant aquatic sources of both CH4 and N2O and puts the estimated fluxes into the global context with measurements done from other climatic regions. 相似文献