云南金平长安金矿矿石类型及分带     

何忠福  吴文辉  蔡培全 《云南地质》2010,29(3):266-268,256

应用氧化铁含量变化确定矿石类型,分带界线初定为1 645米中段,但无法确定混合带界线,开发中很难满足生产。通过柱浸试验浸出率确定矿石类型,即可正确分带。  相似文献   

基于ASTER VNIR-SWIR多光谱遥感数据识别与提取干旱地区岩性信息——以西南天山柯坪隆起东部为例     

时丕龙  付碧宏  二宫芳树 《地质科学》2010,45(1)

ASTER多光谱遥感数据目前可以用于岩石矿物资源信息的识别和提取。本研究尝试利用ASTER可见光近红外(VNIR)和短波红外(SWIR)的多光谱遥感数据提取干旱地区的岩石与矿物信息。基于新疆天山西南缘柯坪隆起东部不同地层单元岩石的化学组成和矿物成份以及VNIR-SWIR谱域光谱吸收特征的分析,我们采用相关吸收波段深度(RBD)和波段比值(BR)方法对研究区的多光谱遥感数据进行图像处理,有效区分和识别了白云岩、石灰岩、砂岩以及阿克苏群的蓝片岩—绿片岩和砂质片岩。白云岩的CO_3~(2-)吸收谱带中心波长位于2.32μm,与灰岩的CO_3~(2-)吸收谱带中心波长位置2.35μm相比,具有向短波长方向移动的特点,据此可以利用RBD7、RBD8分别有效的识别白云岩和灰岩;长英质岩石显示Al-OH和Fe~(3+)VNIR-SWIR吸收特征,而基性-超基性岩石显示Fe~(2+)和Fe、Mg-OH特征,利用不同的铁价态和次要矿物可以区分它们:ASTER band2/band1代表了含Fe~(3+)矿物分布信息、ASTER band5/band4代表了含Fe~(2+)矿物分布信息、RBD6可以估计Al-OH矿物的丰度;砂质/泥质片岩含较多的多硅白云母、绿泥石、黑硬绿泥石以及风化后表面覆盖的其它粘土矿物,在2.21μm(band6)存在有特征的吸收谱带,并且在1.65μm(band 4)具有较高的反射率,而蓝片/绿片岩在2.21μm(band 6)反射率较高,不具有明显特征吸收谱带,同时其在1.65μm(band 4)反射率较低,因此蓝片/绿片岩ASTER band4/band6比值低。应用ASTER band4/band6波段比值可以有效的区分开砂质/泥质片岩与蓝片岩/绿片岩。  相似文献   

北极拉普捷夫海海冰多年变化研究          下载免费PDF全文

姚文峻  赵进平 《极地研究》2013,25(3):218-225

拉普捷夫海是北冰洋的边缘海和冰源地,对北冰洋的海冰变化有重要影响。通过分析AMSR-E海冰密集度数据以及NECP-DOE的风场、温度场数据,结果表明拉普捷夫海海冰在2002—2011年经历了如下过程：重冰年(2002—2004)—过渡性质年份(2005—2006) —轻冰年(2007、2009—2011),即冰情由重向轻转变。研究结果也表明拉普捷夫海的冰情轻重与融冰期长短有较好的相关性,融冰期持续时间越短,冰情越重。4个参数,包括海冰距平指数、最小海冰覆盖率、积温、风驱动指数描述了拉普捷夫海的海冰多年变化过程。海冰距平指数是时间（3—11月）平均下的海冰覆盖率距平值,定量给出了各年冰情的轻重;最小海冰覆盖率是夏季海冰的极限情况,变化范围在0.45%—48.73%,发生时间为8月底至10月上旬。积温是上一个冬季气温积累对当年冰情的影响,结果表明积温是影响当年冰情轻重的主要因素。2008年的上一个冬季经历了异常低温,造成当年的异常重冰年。风驱动指数给出了风场对海冰覆盖率变化的短期影响,与同时期其他年份相比,2006年4月、2007年9月均出现了异常强北风,一定程度上造成了2006年融冰开始时间延后、2007年夏季最小海冰覆盖率的明显偏大。  相似文献   

Leaching evaluation of cement stabilisation / solidification treated kaolin clay     

U.E. John  I. Jefferson  D.I. Boardman  G.S. Ghataora  C.D. Hills 《Engineering Geology》2011,(4):315

Sustainable land management often requires redevelopment of existing and often contaminated Brownfield sites over use of Greenfield or agricultural land. Stabilisation / solidification (S/S) offer a viable remediation option with particular suitability in treating heavy metal contaminants. However, uncertainties over long-term durability and previously cheap landfill disposal costs resulted in limited use in many countries. There is a need to characterise treated material and assess components containment and release, to improve S/S confidence and inform remedial design, using the evaluation of the leaching controlling mechanisms. To improve understanding of key features that will enable improvements to such designs, this paper presents an evaluation of leaching for CEM II stabilised kaolin, using the leaching behaviour of 4 main components—aluminium, silicon, calcium and sulphur. Results show no detrimental implications on chemical durability due to kaolin degradation with hydration under induced alkalinity, with increased formation of stable cementitious minerals. Availabilities for components show that aluminium and silicon had minimal leachability compared to total content, whilst calcium and sulphur show almost total leaching availability. Decreasing calcium and silicon leachability under natural chemical conditions with increased hydration duration supports the increased formation of stable cementitious products with time, using the products of kaolin dissociation.  相似文献   

A signal-to-noise index to quantify the potential for peak detection in sediment-charcoal records     

Ryan F. Kelly  Philip E. Higuera  Feng Sheng Hu 《Quaternary Research》2011,75(1):11-17

Charcoal peaks in lake-sediment records are commonly used to reconstruct fire histories spanning thousands of years, but quantitative methods for evaluating the suitability of records for peak detection are largely lacking. We present a signal-to-noise index (SNI) that quantifies the separation of charcoal peaks (signal) from other variability in a record (noise). We validate the SNI with simulated and empirical charcoal records and show that an SNI > 3 consistently identifies records appropriate for peak detection. The SNI thus offers a means to evaluate the suitability of sediment-charcoal records for reconstructing local fires. MATLAB and R functions for calculating SNI are provided.  相似文献   

PGV/PGA和PGD/PGA随震级和震中距变化的研究          下载免费PDF全文

罗光财  丁海平  王绍博 《地震工程学报》2010,32(2):112-116

以太平洋地震工程研究中心(PEER)和强震动观测系统组织委员会(COSMOS)记录的13次地震的486个台站的三分量地震动峰值数据为基础,按照震级和震中距大小将其分类,得到地震动的峰值比PGV/PGA和PGD/PGA与震级和震中距的关系。结果表明:峰值比随着震级的增大而增大,随着震中距的增大也增大。最后给出了峰值比与震级和震中距的衰减关系,以供抗震设计参考使用。  相似文献   

加卸载响应比孕震积分在新疆地震预测中的综合应用研究     

刘建明  刘月  唐兰兰  李志海  温少妍  张琳琳  罗矩 《地震》2014,34(2):89-97

本文首先利用加卸载响应比孕震积分, 对2001年以来新疆境内南天山西段和喀什—乌恰交汇区发生的4次M_S≥6.0地震, 进行了震例检验。 结果显示, 孕震初期孕震积分在背景值附近波动, 变化平缓。 随着孕震程度的加剧, 孕震积分不断增加至峰值点, 快速回落过程中或恢复后发震。 我们还将加卸载响应比孕震积分初步应用到南天山西段的部分定点形变资料中, 对比分析了哈拉峻台、 乌恰台钻孔倾斜以及乌什水管仪、 伸缩仪和体应变趋势日均值与以台站为中心, 250 km为半径的加卸载响应比孕震积分时序图。 结果表明, ① 哈拉峻台和乌恰台区域内构造应力场应力处于不断加载的过程, 引起了定点形变资料速率的大幅度、 不稳定变化; ② 当构造应力场上的应力处于缓慢不断加载的过程时, 会引起定点形变测项速率方向发生改变, 表现形式为趋势异常; ③ 目前, 南天山西段构造应力场应力水平处于不断加载的过程。  相似文献   

一次飑线过程的闪电活动特征   总被引：2，自引：0，他引：2  

冯桂力  王俊  龚佃利  李海腾  张文 《山东气象》2009,29(1)

结合地闪定位资料和TRMM卫星LIS观测的总闪电资料对一次飑线过程闪电活动进行分析,结果如下:这次飑线过程的正地闪超过了负地闪,占地闪的54.7%.在系统发展的初始阶段全部为正地闪;在系统的快速发展阶段地闪频数明显增大,正地闪比例很高,均在75%以上.在系统成熟至减弱阶段,地闪频数开始下降,而正地闪比例下降,负地闪的比例却越来越大,并占据支配地位.正地闪发生在线对流区(即强回波区内或附近),负地闪发生在层状云区.正地闪并不对应于主上升气流区而是紧邻上升气流区的后部.该雷暴云内闪电活动非常频繁,云地闪比例高达26.1:1.降雹和地面大风区位于正地闪密集区内,地闪频数峰值对应于地面大风阶段.  相似文献   

On the Compensation of Systematic Errors in Marine Gravity Measurements     

Huang Motao  Guan Zheng  Zhai Guojun  Ouyang Yongzhong 《Marine Geodesy》2013,36(3):183-194

Based on an analysis of the source of errors in marine gravity measurements, an error model, firstly, is constructed mathematically which can characterize the change of systematic errors and with which a new crossover adjustment model is presented in this paper. Then, two methods of compensating the systematic errors are proposed, i.e., the self-calibrating adjustment and the a-posteriori compensation. Some questions involved in solving the adjustment problem, such as the rank deficiency, the choice of error model, the weighting of model parameters and the significance test of compensation efficiency, etc., are discussed in detail. Finally, a practical survey network is used as a case study to test the efficiency and reliability of the two compensation methods.  相似文献   

Probability Estimates of Field Areas and Trapped Oil Volumes     

Anderson  Malcolm  Gullco  Robert S. 《Natural Resources Research》2001,10(2):149-158

A portion of a sedimentary basin is subdivided conceptually into hexagons of equal area. The area of each hexagon is equal to the minimum area an oil field should have to be commercial. Hexagons can be full of oil or empty. A field size 1 consists of a cell with oil surrounded by six empty cells; a field size 2 consists of two adjacent cells with oil surrounded by eight empty cells, etc. Principles of Percolation Theory are used to determine the probability distribution of the areas of the oil fields existing in this portion of the basin. The only piece of information necessary to determine this probability distribution is the Success Ratio (number of successful exploration wells/total number of exploration wells drilled in this portion of the basin). This approach has several practical applications.A probabilistic model is introduced to predict to which extent potential oil traps are filled with oil. The model assumes that the probability that an oil unit will end up in a particular trap, is proportional to the surface area of the trap. The model predicts that independently of the distribution of the trap volumes, there will be a critical trap volume. All the traps having a volume less than this critical volume, will be filled to spill point. An equation is deduced to predict, for all traps having a volume greater than the critical, the volume of oil that can be encountered in the trap, provided the volume of the trap is known.  相似文献