Sr speciation in producing SrCO3 with celestite     

Chenglun Liu  Li Zhang  Longjun Xu  Zhimin Su  Taiping Xie  Yuan Wang 《中国地球化学学报》2014,33(3):244-247

Strontium speciation transferring in strontium residue and mixing strontium ore are investigated with extracting experiment, X-ray powder diffraction （XRD）, X-ray fluorescence spectrometer （XRF） and Atomic Absorption Spectroscopy （AAS）. The results show that there are strontium carbonate, strontium sulfate, strontium sulfide, and a little amount of strontium silicate and strontium ferrite in strontium residue. Impurities in strontium residue mainly contain carbonate and oxide of calcium, iron, magnesium and aluminum etc. The amount of strontium sulfide in strontium residue is larger than that in strontium ore. And a little strontium silicate and strontium ferrite are found in strontium ore. It is concluded that acid soluble method is used firstly in the process of producing strontium carbonate from mixing strontium ore. In addition, mechanical smash method and surface active treatment to strontium samples are beneficial to the ratio-leaching increase of strontium. The research achievement helps to save energy and decrease pollutants emission in strontium processing industry.  相似文献   

大洋锰结核氨浸渣脱硫产物处理含镉废水的研究   总被引：1，自引：0，他引：1  

汪伦  陈天虎  常冬寅  刘海波  陈冬 《岩石矿物学杂志》2011,30(6):1001-1006

研究了大洋锰结核氨浸渣脱硫产物去除废水中镉离子的多种影响因素,如接触时间、脱硫产物粒径、溶液pH值、初始镉离子浓度和吸附剂量。并利用X射线粉末衍射(XRD)、场扫描电镜(SEM)、X射线光电子能谱(XPS)对材料和产物进行了表征。结果表明减小脱硫产物粒径、增大吸附剂量等有利于提高去除效果;大洋锰结核氨浸渣脱硫产物去除水中镉离子是基于离子交换反应的原理:MnS+Cd2+→CdS+Mn2+。  相似文献   

Anthropogenic Effect on Deposition Dynamics of Lake Sediments Based on ~（137）Cs and ~（210）Pb_（ex） Techniques in Jiuzhaigou National Nature Reserve,China     

LIANG Kangkang  HU Xinxin  LI Shiguang  HUANG Chengmin  TANG Ya 《中国地理科学(英文版)》2014,24(2):180-190

Radionuclide dating techniques characterized by137Cs and210Pbex have recently been applied in the study of lake sediments around the world.In this study,a chronological series of sediment cores was established based on137Cs and210Pbex analyses along with the evaluation of sediment properties,such as particle size distribution,total organic carbon(TOC),carbonate content,and acid-insoluble residue,to study sediment accumulation rates,sediment sources,and responses to human activities in the Jiuzhaigou National Nature Reserve in southwestern China.In terms of the particle size distribution of sediments,silt content was the highest,and clay and sand contents were relatively low.The sediments displayed high TOC contents because of the significant amounts of vegetation grown in the lakes.The carbonate content was also high due to the overall geological background of carbonates in Jiuzhaigou.Carbonate content tended to decline from top to bottom in the sediment cores,whereas the acid-insoluble residue tended to increase.These results suggested that the depth variation of the environmental parameters of the sediments in two lakes in Jiuzhaigou would correspond to each other.The results indicated that the sediment rate of Jiuzhaigou was generally high with strong siltation,indicating that serious soil loss was induced by intensive human activities in the basin over the past decades.The increases in the mass accumulation rate,contents of acid-insoluble residue,and mean particle size during the periods of 1840–1900s,late 1930s–early 1950s,1966–1978,and2003–2006 revealed the occurrence of severe soil and water loss as a result of extensive agricultural expansion,large-scale deforestation,and road construction in Jiuzhaigou.The deposition rate and the properties of lacustrine sediments could reflect the significant impact of human activities on lake sedimentation during Jiuzhaigou′s history.  相似文献   

电厂冷却水余氯对海洋环境影响的探讨   总被引：3，自引：0，他引：3  

温伟英  黄小平  吴仕权  何悦强 《热带海洋学报》1993,(3)

根据室内实验和对广东某电厂的现场测试,探讨该电厂冷却水经氯化处理后,海水中余氯的衰减特征和余氯对水环境的影响。研究表明,余氯衰减很快,其对外环境的影响很小。  相似文献   

利用前临界PcP-PKiKP资料研究中国东部内核边界性质   总被引：1，自引：1，他引：0       下载免费PDF全文

申中寅  艾印双  何玉梅  姜明明 《地球物理学报》2013,56(10):3324-3333

前临界内核边界反射震相PKiKP与核幔边界反射震相PcP构成组合,能有效压制浅部结构及震源因素的干扰,提供了对内核边界精细结构的直接约束. 本研究从华北克拉通西北部密集流动地震台阵一年观测资料中筛选出8个地震事件,得到共计 73对PcP-PKiKP组合,覆盖了从朝鲜半岛到我国东北及华中地区下方的内核边界. 本文系统分析了走时残差和振幅比数据,结果显示:(1)密集台阵资料有助于前临界PKiKP震相拾取,而浅源地震亦可提供高质量的PcP-PKiKP观测资料.(2)走时残差呈现了自西北向东南从正常到负异常的迅速变化(沿内核边界70 km范围内>0.5 s), 限制了研究区域内核界面不超过3 km的起伏. (3)相对振幅比变化表明了研究区内核边界密度差北西-南东向的系统增加, 揭示了内核结晶环境的小尺度扰动.  相似文献   

泡叶藻及海带藻渣中岩藻聚糖硫酸酯的提取及其抗氧化活性   总被引：1，自引：0，他引：1  

刘旭  曲桂燕  周裔彬  袁毅  韩丽君 《海洋科学》2013,37(12):34-39

采用超声波辅助提取方法提取泡叶藻(Ascophyllum mackaii)及海带(Laminaria japonica)藻渣中岩藻聚糖硫酸酯, 以均匀试验设计建立回归模型优化高效制备提取工艺。采用高效凝胶过滤色谱法(HPGPC)进行了相对分子质量检测及理化性质分析; 利用Fenton 反应检测法、邻苯三酚自氧化法等进行了抗氧化活性研究。结果表明, 优化的高效制备技术的超声波最佳条件为超声70 min, 温度为90℃,水提时间2 h, 料液比1︰ 80, 泡叶藻及海带藻渣中岩藻聚糖硫酸酯的高效提取率分别为4.49%和3.69%,分子质量分别为142 kDa 和136 kDa, 泡叶藻和海带藻渣中的岩藻聚糖硫酸酯均具有较好的清除超氧阴离子自由基、羟自由基能力及还原能力。海带的抗氧化活性总体略高于泡叶藻。  相似文献   

我国南海海鱼中有机氯农药残留分析   总被引：3，自引：0，他引：3  

曾凡刚 《岩矿测试》2010,29(3):241-244

建立了凝胶渗透色谱前处理,毛细管气相色谱测定我国南海海鱼中11种有机氯农药的方法。分析了油鲽鱼块、鲷鱼片、银鳕鱼、哈哈鱼块、海鳗鱼中的有机氯农药残留情况,发现在禁用20多年后,六六六(HCHs)、滴滴涕(DDTs)、狄氏剂、环氧七氯在鱼肉中均有不同程度的检出,其中滴滴涕的残留水平最高达到26.73μg/kg。研究发现我国南海海鱼中4种HCH的总残留量高于北京市场上的淡水鱼的残留水平;多数有机氯农药残留污染的平均水平也高于英国和巴西等国鱼类的水平。南海海鱼中有机氯农药残留水平具有指示环境污染的意义。  相似文献   

基于BiCMOS工艺的高速10位A/D转换器研究     

赵继德  马传龙  李应良 《成都信息工程学院学报》2005,20(3):302-305

研究一种基于BICMOS工艺的高速十位A／D转换器，这种转换器采用二步分区式结构，包含了二个5位的全平行(闪烁型)ADC。在BiCMOS工艺基础上，根据A／D转换器的工作原理、结构特点设计出比较器电路，残差放大器。最后对设计的比较器和残差放大器电路进行仿真，得出比较器瞬态响应突变时间为600ns，残差放大器建立时间为1．5μs、放大增益约为2dB，其性能指标超出了同类器件。  相似文献   

基于梯度的干涉条纹图圆周期滤波     

刘利力  舒宁  龚衍  章志佳 《武汉大学学报(信息科学版)》2005,30(8):716-719

在分析了一些现有滤波特点的基础上,根据干涉条纹图的连续性、圆周期性等主要特征,提出了一种基于梯度加权的圆周期均值滤波。将该方法用于由ERS-1原始数据生成的干涉条纹,结果证明,该方法不仅很好地抑制了噪声,而且具有良好的干涉条纹保持特性。  相似文献   

Multi-criteria analysis for the identification of waste disposal areas   总被引：1，自引：0，他引：1  

Maria Lúcia Calijuri  Eder T. Marques  Juliana F. Lorentz  Roberto F. Azevedo  Carlos A. B. Carvalho 《Geotechnical and Geological Engineering》2004,22(2):299-312

The municipality of Cachoeiro de Itapemirim (ES) is currently the largest domestic producer and exporter of marble and granite in Brazil. The processing of the rock, especially the sawing results in a large volume of waste, including the abrasives used during sawing and the off-cut pieces. Presently these waste products are disposed of without proper environmental protection and cause pollution to surface water and groundwater resources, including silting, an increase in hardness and increased aluminium values in the groundwater. In order to minimize the harmful effects of these practices on the environment, a research project was undertaken to identify potential disposal sites for the generated waste. A multi-criteria approach was followed during which a database was compiled of all the companies generating waste products and also including a baseline environmental study of the region, integrated analysis (multi-criteria analysis) of the restriction factors and the preliminary identification of possible disposal sites. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献