A Genesis Analysis of the Regional Gravity and Magnetic Anomalies in the Northern Part of Eastern Xinjiang,Northwest China

The authors discuss the genesis of the regional gravity and magnetic anomalies in the northern part of Eastern Xinjiang, a correlation analysis was carried out between the regional gravity anomaly and the regional magnetic anomaly. Through data processing and integrated interpretation of the gravity and magnetic data in the study area, the Bouguer gravity anomaly and the magnetic anomaly by reduction to the pole were separated. Then, the regional gravity and magnetic anomalies across multiple scales were extracted; in addition, the correlation coefficients between the regional gravity anomaly and the regional magnetic anomaly at different scales were calculated. Finally, the features of the gravity and magnetic fields, their geological significance, and the origins of these regional gravity and magnetic anomalies were analyzed. The results showed that the regional negative gravity anomaly in the Turpan-Hami basin and the Santanghu basin was mainly caused by Cenozoic and Mesozoic strata; the regional positive magnetic anomaly was mainly caused by the Precambrian metamorphic basement. The study revealed that the regional positive gravity and magnetic anomalies resulted from the crust and the mantle substances in the eastern part of the Junggar basin. While the regional positive gravity anomaly was mainly caused by Pre-Mesozoic strata, and the regional negative magnetic anomaly by the sedimentary formation and intermediate acid rocks in the Bogeda-Harlike folded zone and the Jueluotage anticlinorium. The regional negative gravity and magnetic anomalies in the active zone of the northern margin of Tarim were mainly caused by the sedimentary formation and intermediate acid rocks.     

一般地质物料中Au的物相分析

Au的化学物相分析是查明元素在样品中各种相态(状态)存在的含量,为化探异常评价、地质研究、矿床评价和选矿试验提供所需的物质组成和元素在矿石中的赋存状态等提供理论指导。由于Au在自然界中主要呈自然Au(Au0)状态存在。因此Au的物相分析,通常不是测定Au本身的各种状态,而是测定自然Au的各种赋存状态。本文分析系统可测定裸露和半裸露的自然Au、碳酸盐包裹Au、铅锌铜硫化物包裹Au、褐铁矿包裹Au、黄铁矿包裹Au和石英硅酸盐包裹Au。     

中国近海卫星测高数据的重力异常反演——II.沿轨迹垂线偏差反演法

给出了一套基于直角坐标系下的垂线偏差求解重力异常公式 ,并将之发展成为一套新的沿轨迹重力异常求解公式。据此 ,利用Geosat/GM、ERS 1/ 35d及Topex/Posei don 3种测高数据 ,反演了南中国海域 ( 0°～ 2 5°N ,10 5°～ 12 2°E)的 2’× 2’重力异常———IGG S。通过与实际船测资料和国际同行提供的重力模型相比 ,IGG S总体精度达到 10× 10 - 5m/s2 。     

在不完备信息系统中基于VPRSM的约简异常分析

属性约简问题的关键在于约简集合能否表达与原属性集完全一致的信息。分析了完备信息系统中基于变精度粗糙集模型属性约简异常出现的原因,并将其扩展到不完备信息系统中,在文献[1]的基础上,给出了不完备信息系统中基于集对分析的VPRSM的约简定义,既能保证在不完备信息系统中基于变精度约简的准确性,又能增加灵活性和容噪能力。     

嘎拉山、福草山地区化探异常特征及金矿找矿意义

黑龙江省嫩江县嘎拉山、福草山地区位于小兴安岭山脉北端, 为典型的森林沼泽-冻土景观区[1] 。由于该区沼泽密布、地表覆盖较厚, 地质工作难度较大, 因此找矿工作一直没有大的突破。武警黄金部队于2007～2008年采用化探方法在该地区开展了岩金找矿工作, 圈出了多个地球化学异常。其中水系HS-Au-15号异常规模大、浓集中心明显、浓度分带清楚, 并具有较好的异常组合特征, 成矿地质条件有利。通过土壤面积性查证和槽探揭露验证工作, 在该异常内发现了金矿体5条, 最高品位达26.18×10-6。说明该区具有较好的找矿前景, 为岩金找矿工作指明了方向, 也为下一步全面开展地质找矿工作奠定了坚实的基础。     

A RECONSTRUCTION OF THE KEY TO BEALE CIPHER NUMBER TWO

A reconstruction of the key used to encrypt B2 (Beale Cipher Number 2) reveals greater statistical anomalies in Bl than previously reported by Gillogly [8]. The 1885 pamphlet versions of the ciphers are used in this analysis. Several explanations of these anomalies are discussed. The application of artificial intelligence techniques to automated cryptanalysis of the Beale Ciphers is discussed.     

Normal state of short coherence length superconductors: Qualitative differences between spin and charge correlations

The temperature scaleT* at which the amplitude of the order parameter is formed is in general much higher than theT _c at which phase coherence is established in short coherence length superconductors. Using quantum Monte Carlo simulations for the attractive Hubbard model we show that for a degenerate 2D system the spin and charge responses show qualitatively different behavior in the normal state in the temperature rangeT _c <T<T*. We find that _s is stronglyT-dependent whiledn/d is independent ofT. A pseudo-gap develops in the one-particle density of states and leads to anomalous behavior of the NMR relaxation rate 1/T ₁ T _s (T) characteristic of spin gap behavior in the high-T _c materials.     

利用Aster数据提取矿化蚀变异常——以新泰市石河庄硫铁矿为例

以新泰市石河庄硫铁矿为例,在蚀变异常找矿的地质依据和蚀变异常提取的波谱依据的指导下,采用去干扰主分量门限化技术对ASTER遥感图像进行铝、镁羟基异常和铁染异常的蚀变信息提取,通过已知矿床与蚀变异常的关系分析,发现其提取结果与已知矿体、蚀变带吻合较好.然后结合已知矿床的成矿模式和充分考虑已知矿区的外围地段,圈定了1处成矿靶区,为找矿预测与评价工作提供了参考.     

两种容量维方法提取化探数据异常下限效果对比

对云南某地1 850个(其中11个点水域覆盖,以0代替)水系沉积物Au元素化探数据进行含量-求和法与含量-数目法分维值计算,均表明Au含量数据存在两个无标度区,反映研究区Au元素存在两个不同层次的分布,即背景场和异常场。两者所确定的异常下限相同,但前者分维值(3.299 9和0.083 1)均大于后者分维值(2.679 2和0.013 5)。依据异常下限将异常场分解出来。Au元素异常场三维曲面图与原始数据综合场三维曲面图对比,不仅保留基本异常信息,并且突出弱异常信息,反映弱异常区不同矿化中心的叠加。Au元素背景场与异常场均存在聚集与分散双重性质。背景区金元素分布整体分散连续,局部微弱聚集,异常区整体高度聚集,局部分散连续。     

基于模糊综合评判法的建三江垦区旱涝等级的研究

旱涝评价是制定防灾减灾预案中的一个重要环节.利用农垦建三江分局七星农场54a的历史气象资料,分析了旱涝评价指标和评价标准,建立了旱涝多因子模糊综合评价模型,并对该农场2006-2010年的旱涝等级进行分析评价,得到了符合实际情况的结果,验证了该方法的适用性.