砂岩型铀矿床层间氧化带前锋区稀有元素富集机制   总被引：3，自引：0，他引：3  

陈祖伊  郭庆银 《铀矿地质》2010,26(1):1-8

在深入研究砂岩型铀矿床层间氧化带各地球化学分带中铀及其伴生元素的分布规律时,发现一些单价态(不变价)元素也常常富集在层间氧化带前锋区,其典型代表是钪(Sc)、钇(Y)和稀土元素(REE)等。作者在综合分析前苏联众多砂岩型铀矿床各地球化学分带中各种元素大量测试数据的基础上,论述了层间氧化带前锋区Eh值和pH值的变化规律以及它们所导致的变价元素(U、Se、Mo和V)和不变价元素(Sc、Y和REE)的分布规律和富集机制。实际上,层间氧化带前锋区既是氧化-还原电位(Eh值)又是酸碱度(pH值)的急剧变化区,两者大致同步消长。层间氧化带前锋区有两类地球化学障:单纯的还原障和还原-碱性综合障。两种地球化学障的发育与强度取决于原始未氧化岩石中硫化物、有机质和碳酸盐的含量。  相似文献   

钾长石矿物在全新世样品光释光测年中的应用与校正问题   总被引：9，自引：9，他引：0       下载免费PDF全文

李国强  赵晖  文星  彭海梅  陈发虎 《第四纪研究》2010,30(1):54-61

使用钾长石进行释光测年时,由于长石的释光信号存在异常衰减,会导致沉积事件年龄的低估。对中国北方4个全新世样品分别使用石英和钾长石矿物组分释光测年,通过测量钾长石的衰退系数(g值)对钾长石使用再生剂量法获得的表征年龄进行了校正。发现对于本文所研究的年轻样品钾长石表征年龄与石英年龄相比系统偏小约2％～9％,钾长石校正年龄与石英年龄相比则严重偏大约16％～40％,表明使用g值无法校正年轻样品的钾长石年龄。对于年轻样品,钾长石IRSL信号异常衰减现象对测年结果的影响是可以忽略的。  相似文献   

北京地面沉降Js型静力水准自动化监测系统量程调整及修正值添加方法     

罗勇  贾三满  赵波  周毅 《城市地质》2010,5(4):36-39

本文介绍了Js型静力水准自动化监测系统构成。在多年监测的基础上,对该系统在地面沉降监测中量程的调节量、调节方向和调节方法进行了总结,对量程调节后的修正值添加原理、时机选择和方法进行了探讨。  相似文献   

企业文化的战略价值浅析     

罗拱北 《中国勘察设计》2010,(7):72-75

企业文化对企业长期经营业绩有着重要的影响,它很可能成为决定企业兴衰的关键因素,但是直到今天把企业文化发扬光大并成为核心竞争力的企业仍然是极少数。究其原因,主要是理论研究的多,企业家在实践中把企业文化建设当作一种自觉行动的少,没有把企业文化的价值上升到战略高度来加以认识,企业文化缺少核心思想和系统规划,缺乏对企业愿景的描绘,对职工群众缺乏吸引力和凝聚力,以至在市场竞争中难以发挥文化制胜的作用。如何把企业文化培育成一种不可复制的重要战略资源,笔者认为首先要对企业文化进行提炼,找出企业的核心价值观,系统策划企业文化内容,并在员工队伍及客户全体中持续宣贯培育,最终达到员工拥护、客户认同的目标,以文化的软实力为企业创造出硬价值。  相似文献   

关于水泥土搅拌桩复合地基载荷试验的探讨          下载免费PDF全文

杜文义  李容 《探矿工程》2010,37(12):41-45

通过试验结果的对比,讨论了地基土含水量变化对水泥土搅拌桩复合地基承载力的影响,建议采用＂10 mm厚的水泥砂浆对整个试验场地进行封闭保护＂来减低其影响。通过2个典型试验场地试验结果的对比分析,讨论了按现行规范规定确定复合地基承载力特征值可能存在的问题;建议进行破坏性试验,先定极限荷载,然后再根据＂先评价复合地基均匀性、再根据安全系数确定承载力＂的原则确定复合地基的承载力。  相似文献   

高邮凹陷北斜坡中部泰州组烃源岩评价     

仇永峰  陈平原  崔晓晓 《上海国土资源》2010,31(Z1)

通过对高邮凹陷北斜坡中部沙埝地区沙50A井泰二段暗色泥岩系统取样,详细评价了其有机质丰度、类型、成熟度等各项指标,并依据泰州组烃源岩评价结果和成熟门限深度值划定了高邮凹陷泰州组有效烃源岩的分布范围,计算了相应的资源量。结果表明,该区泰州组有效烃源岩主要分布于泰二段底部六尖峰泥灰岩段,该段有机质丰度较高,类型较好,具有较好生油能力;该区泰二段烃源岩已处于成熟阶段,对应门限深度为2550m;有效烃源岩集中分布于高邮凹陷北斜坡中东部地区,生油量为2.9×10~8t,占高邮凹陷总生油量的60%,具有较大的勘探潜力。  相似文献   

Process identification through rejection of model structures in a mid‐mountainous rural catchment: observations of rainfall–runoff response,geophysical conditions and model inter‐comparison     

Thomas Graeff  Erwin Zehe  Dominik Reusser  Erika Lück  Boris Schröder  Gerald Wenk  Hermann John  Axel Bronstert 《水文研究》2009,23(5):702-718

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Hydrological extremes in the Poyang Lake basin,China: changing properties,causes and impacts     

Qiang Zhang  Peng Sun  Xiaohong Chen  Tao Jiang 《水文研究》2011,25(20):3121-3130

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Homogeneity analysis of Turkish meteorological data set   总被引：2，自引：0，他引：2  

Sinan Sahin  H. Kerem Cigizoglu 《水文研究》2010,24(8):981-992

The missing value interpolation and homogeneity analysis were performed on the meteorological data of Turkey. The data set has the observations of six variables: the maximum air temperature, the minimum air temperature, the mean air temperature, the total precipitation, the relative humidity and the local pressure of 232 stations for the period 1974–2002. The missing values on the monthly data set were estimated using two methods: the linear regression (LR) and the expectation maximization (EM) algorithm. Because of higher correlations between test and reference series, EM algorithm results were preferred. The homogeneity analysis was performed on the annual data using a relative test and four absolute homogeneity tests were used for the stations where non‐testable series were found due to the low correlation coefficients between the test and the reference series. A comparison was accomplished by the graphics where relative and absolute tests provided different outcomes. Absolute tests failed to detect the inhomogeneities in the precipitation series at the significance level 1%. Interestingly, most of the inhomogeneities detected on the temperature variables existed in the Aegean region of Turkey. It is considered that theseinhomogeneities were mostly caused by non‐natural effects such as relocation. Because of changes at topography at short distance in this region intensify non‐random characteristics of the temperature series when relocation occurs even in small distances. The marine effect, which causes artifical cooling effect due to sea breezes has important impact on temperature series and the orograhpy allows this impact go through the inner parts in this region. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Empirical analysis of path effects on prediction equations of pseudo‐velocity response spectra in northern Japan     

Yadab P. Dhakal  Nobuo Takai  Tsutomu Sasatani 《地震工程与结构动力学》2010,39(4):443-461

We study path effects on prediction equations of pseudo‐velocity response spectra (natural period of 0.1–5.0 s) in northern Japan, where heterogeneous attenuation structure exists. The path effects have been examined by comparing the regression analysis results for two different prediction equations. The first equation consists of a single term of anelastic attenuation conventionally. The second equation consists of two terms of anelastic attenuation in consideration of the heterogeneous attenuation structure. In the second equation, we divide a source‐to‐site distance into two distances at the attenuation boundary beneath the volcanic front. The boundary is considered to separate the relatively high Q fore‐arc side mantle wedge (FAMW) from the low Q back‐arc side mantle wedge (BAMW). Strong motion records (hypocentral distances less than 300 km) from interplate and intraslab events with Mw 5.1–7.3 are used. Regression analysis results show that the standard errors are significantly reduced by the second prediction equation at short periods (0.1–0.5 s), whereas the difference in standard errors from both prediction equations is negligible at intermediate and long periods. The Qs values (quality factor for S‐wave) converted from two anelastic attenuation coefficients for the second prediction equation are remarkably similar to the path‐averaged Qs values for the FAMW and BAMW by other studies using spectral inversion method. From these findings, we conclude that the path effects on the prediction equation of pseudo‐velocity response spectra are satisfactorily accomplished by the second prediction equation. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献