塞尔维亚贾达尔盆地超大型锂硼矿床   总被引：11，自引：0，他引：11  

赵元艺  符家骏  李运 《地质论评》2015,61(1):34-44

锂和硼有着广泛的用途,我国常年大量进口锂和硼矿石。近些年在塞尔维亚贾达尔盆地中发现一个特殊的超大型锂硼矿床,与Rio Tinto、Pan Global Resources和Ultra Lithium等公司一样,我国地勘单位正在这一矿区进行勘查工作,因此对该地区的锂硼矿床地质特征进行总结和报道很有必要。该矿床的矿石矿物是世界独有的既含锂也含硼的羟硼硅钠锂石(Jadarite)[LiNaSiB_3O_7(OH)],其含B_2O_3 47.2%,含Li_2O 7.3%,密度2.46g/cm~3。已有资料显示,找矿标志层为中新统湖相沉积岩中的凝灰岩层,矿体具有电阻率小于4.4Ω·m和重力异常值小于-15mGal的特征。该矿床设施齐全,且选矿和化工处理简便,短期内可获得硼和锂产品。  相似文献   

海洋沉积物细菌群落结构对芘和苯甲酸钠胁迫的响应     

孙向楠  胡晓珂  王慧 《海洋与湖沼》2015,46(6):1304-1311

应用分子生态学方法, 研究在不同芳香族化合物胁迫下海洋沉积物中细菌群落结构的演替 规律。在实验室建立驯化系统, 在海洋沉积物中分别添加芘和苯甲酸钠, 采用Illumina MiSeq 高通量 测序技术分析实验组和对照组细菌群落16S rRNA 基因V3-V4 可变区数量的组成及变化, 研究沉积物 中添加芘、苯甲酸钠后, 微生物群落多样性和群落结构的变化。实验结果表明: 芘、苯甲酸钠极大地 降低了海洋沉积物中菌群丰度和多样性; 在添加苯甲酸钠的实验组, 变形杆菌门中海杆菌属 (Marinobacter)、假海源菌属(Pseudidiomarina)的细菌显著富集; 在添加芘实验组中拟杆菌门中的 Balneola 属、碳酸噬胞菌属(Aequorivita)极大富集。初步分析了在海洋沉积物环境中不同多环芳烃胁迫 下细菌群落结构的演替特征, 实验结果为海洋环境中针对不同芳香烃的微生物修复提供理论依据。  相似文献   

Non-local memory effects of the electromotive force by fluid motion with helicity and two-dimensional periodicity     

Kumiko Hori  Shigeo Yoshida 《地球物理与天体物理流体动力学》2013,107(6):601-632

In mean-field dynamo theory, the electromotive force term 〈u′ × B′〉 due to small-scale fields connects the small-scale magnetic field with the large-scale field. This term is usually approximated as the α-effect, assumed to be instantaneous in time and local in space. However, the approximation is valid only when the magnetic Reynolds number Rm is much less than unity, and is inappropriate when Rm ? 1, which is the condition satisfied in the Earth's core or solar convection zone. We introduce a function φ _qr as a non-local and non-instantaneous generalization of the usual α-effect and examine its behaviour as a function of Rm in the range 1/64 ≤ Rm ≤ 10 for a kinematic dynamo model. We use the flow of G.O. Roberts 1972 Roberts, GO. 1972. Dynamo action of fluid motions with two-dimensional periodicity. Phil. Trans. Roy. Soc. London Ser. A, 271: 411–454. [Crossref], [Web of Science ®] , [Google Scholar] (Phil, Trans. Roy. Soc. London Ser. A, 1972, 271, 411–454), which is steady and has non-zero helicities and two-dimensional periodicity. As a result, we identify three regions in Rm space according to the behaviour of the function φ _qr : (i) Rm ? 1/4, where the function φ _qr is local and instantaneous and can be approximated by the traditional α and β effects, (ii) 1/4 ? Rm ? 4, where the deviation from the traditional α and β effects increases and non-localness and non-instantaneousness increase, and (iii) Rm ? 4, where boundary layers develop fully and non-localness and non-instantaneousness are prominent. We show that the non-local memory effect for Rm ? 4 strongly affects the dynamo action and explains an observed augmentation of the growth rate in the dispersion relation. The results imply that the non-local memory effect of the electromotive force should be important in the geodynamo or the solar dynamo.  相似文献   

Weakly nonlinear analysis of the  α effect     

D. Gérard-varet 《地球物理与天体物理流体动力学》2013,107(3-4):171-184

We address mathematical issues raised by the so-called α?effect of dynamo theory, which is a dynamo mechanism arising in conducting flows with small scale fluctuations. Analytical results on the α?effect concern the linear induction equation, and are usually claimed to hold for the whole magnetohydrodynamics (MHD) system, as long as the amplitude of the perturbations is small. We discuss the justification of that claim, in the case of periodic fluctuations of the fields. We show a nonlinear instability result on the MHD system, that predicts dynamo action for a large class of high frequency periodic flows, up to the fully nonlinear regime.  相似文献   

α径迹测量在非洲特殊环境下的应用及效果     

郑明良 《铀矿地质》2012,(1):52-57

在非洲纳米比亚开展了α径迹测量。针对非洲地区与国内迥然不同的特殊地质和恶劣气候环境,采取了各种应对措施,保证了测量的高灵敏度和准确性;经与钻探资料对比,径迹密度与放射性异常对应很好,测量效果显著。使α径迹测量这一物探找铀矿方法在非洲特殊环境的条件下得到全新的阐释。  相似文献   

西昆仑卡拉牙斯卡克Pb——Zn——Cu 多金属矿床控矿构造及成矿模式     

于换涛  刘继顺  刘文恒  王天国  李曦 《世界地质》2013,32(4):733-740

运用地质与地球化学方法,对西昆仑卡拉牙斯卡克矿区控矿构造及成矿模式进行了研究。矿床地球化学测试δ34 S 为－ 5. 3‰ ～ － 32. 6‰,206 Pb /204 Pb 为17. 712 ～ 18. 082,207 Pb /204 Pb 为15. 358 ～ 15. 664,208Pb /204Pb 为37. 513 ～ 38. 399。分析显示,泥盆-石炭纪时期深部成矿物质在构造或其他动力的作用下沿区域深大断裂上涌至地表,与碎屑物质共同沉淀形成矿源层。后经主要成分为天水的流体萃取,形成含矿热液,然后在矿区构造系统中运移、富集成矿-即区域构造控制矿源层形成。矿区内低角度逆掩断层( 导矿构造) 和高角度逆冲断层及其派生的次级节理裂隙( 容矿构造) 控制矿体的形成。  相似文献   

Preconcentration by Coprecipitation of Copper and Nickel with Mo(VI)/Triazole Derivative System and Their Determinations by Flame Atomic Absorption Spectrometry in Food and Water Samples     

Duygu Ozdes  Celal Duran  Hacer Bayrak  Volkan Numan Bulut  Mehmet Tufekcı 《洁净——土壤、空气、水》2012,40(2):211-217

A new separation and preconcentration technique based on coprecipitation of Cu(II) and Ni(II) ions by the aid of Mo(VI)/di‐tert‐butyl{methylenebis[5‐(chlorobenzyl)‐4H‐1,2,4‐triazol‐3,4‐diyl]}biscarbamate (BUMECTAC) precipitate has been established. The Mo(VI)/BUMECTAC precipitate was dissolved by concentrated HNO₃ and the solution was completed to 5.0 mL with distilled/deionized water. The levels of the analyte ions were determined by flame atomic absorption spectrometer. The effects of experimental conditions like HNO₃ concentration, amount of BUMECTAC and Mo(VI), sample volume, etc. and also the influences of some foreign ions were investigated in detail on the quantitative recoveries of analyte ions. The preconcentration factors were found to be 40 for Cu(II) and 100 for Ni(II) ions. The detection limits for Cu(II) and Ni(II) ions based on 3σ (N:10) were 0.43 and 0.70 µg L^?1, respectively. The relative standard deviations were found to be lower than 4.0% for both analyte ions. The accuracy of the method was checked by spiked/recovery tests and the analysis of two certified reference materials (Environment Canada TM‐25.3 and CRM‐SA‐C Sandy Soil C). The procedure was successfully applied to sea water and stream water as liquid samples and baby food as solid sample in order to determine the levels of Cu(II) and Ni(II) ions.  相似文献   

基于低空无人机搭载可见光近红外传感器的太湖蓝藻监测   总被引：1，自引：0，他引：1       下载免费PDF全文

张蔚  何正兴 《山东国土资源》2013,29(8)

传统卫星遥感手段因受其访问周期的限制,较难在时间频率上保证数据的及时性。低空无人机搭载轻小型传感器,以其机动、快速、经济等优势,在环境监测等领域日益发挥重要作用。面向太湖蓝藻监测需求,探索了一种基于低空无人机搭载可见光近红外传感器的监测方法。在系统规划和平台设计的基础上,选取太湖梅梁湖湖区进行试验。依据前人经验,采用可见光和近红外波段及其组合方式提取蓝藻信息,并与试验数据验证。该方法可为蓝藻灾害的防灾、减灾、救灾等提供辅助手段和决策支持。  相似文献   

Tempo-spatial variation of nutrient and chlorophyll-α concentrations from summer to winter in the Zhangzi Island Area (Northern Yellow Sea)   总被引：1，自引：0，他引：1  

YIN Jiehui  ZHAO Zengxia  ZHANG Guangtao  WANG Shiwei  WAN Aiyong 《中国海洋大学学报(英文版)》2013,12(3):373-384

Nutrient and Chlorophyll-a (Chl-a) concentrations were investigated monthly along three transects extending from a mariculture area to open waters around the Zhangzi Island area from July to December 2009. The objective of this study is to illustrate food availability to the bottom-sowed scallop Patinopecten yessoensis under the influences of the Yellow Sea Cold Water Mass (YSCWM), freshwater input and feedbacks of cultivated scallops. Significant thermal stratification was present in open waters from July to October, and salinity decreased in July and August in surface layers in the mariculture area. Nutrient concentrations increased with depth in both areas in summer, but were similar through water column in November and December. On average, nutrient increased from summer to autumn in all components except ammonia. Nutrient concentrations lower than the minimum thresholds for phytoplankton growth were present only in upper layers in summer, but stoichiometric nitrogen limitation existed in the entire investigation period. Column-averaged Chl-a concentration was lower in open waters than in mariculture area in all months. It increased significantly in mariculture area in August and October, and was less variable in open waters. Our results show that nutrients limitation to phytoplankton growth is present mainly in upper layer in association with stratification caused by YSCWM in summer. Freshwater input and upwelling of nutrients accumulated in YSCWM can stimulate phytoplankton production in mariculture area. Farming activities may change stoichiometric nutrient ratios but have less influence on Chl-a concentration.  相似文献   

废旧金属拆解场地浅层地下水芘污染特征与分析          下载免费PDF全文

姚洪华  张达政 《水文地质工程地质》2012,39(3):120-123

在分析废旧金属拆解场地浅层地下水中芘的检出和分布特征的基础上,对地下水中芘的污染来源、污染途径和污染控制因素进行了探讨.研究结果表明,场地中心和地下水下游2km范围内芘污染明显,垂直于地下水流向芘迁移距离较小,一般小于0.5km.芘在地下水中的迁移转化受地下水中pH、Eh及DO等因素的控制,弱酸性或中性环境以及厌氧强还原条件下,芘易于检出和迁移,一般难以生物降解.  相似文献