柿竹园矿床S同位素地球化学研究

通过硫同位素低温平衡系统,分析平衡条件下δ~(34)S_(H_2S)与δ34S热液偏差,获得成矿流体的含硫组分以H_2S为主。成矿阶段δ~(34_S值变化范围狭窄,呈塔式分布,具有岩浆硫特征,柿竹园矿床矿石中的硫来自岩浆流体,即千里山花岗岩。硫同位素fO_2—pH值关系图,投影得出350℃时,fO_2为-28.3~-31.5;250℃时,fO_2为-35.4~-37.5。     

基于神经网络的时间域直升机电磁数据电导率深度成像

采用G-S变换以及高斯数值积分法,形成了时间域直升机的航空电磁响应正演样本集,分析了飞机测量过程中吊舱高度变化对电磁响应的影响,并将吊舱高度的变化等效成电导率为零的假层厚度的变化,以去除高度计等的影响.以假层半空间模型为基础,研究了基于人工神经网络的电导率深度成像算法,通过分析两个三层模型的电导率深度成像结果得出,神经网络方法计算时间域航空电磁探测的视电导率精度较高,特别是对高阻层的视电导率计算.     

求解大样本核主成分分析模型的Lanczos算法

求解核主成分分析模型的技术关键是确定核矩阵端部的较大特征对。把求解大规模对称矩阵端部特征对问题的基本方法--Lanczos算法应用于核主成分分析模型的求解,设计了大样本核主成分分析模型求解的实用算法。在clapack和nu TRLan两个软件包的基础上,开发了大样本核主成分分析模型求解算法的VC++程序。用高光谱遥感图像数据进行模型求解算法的应用试验研究,证明了大样本核主成分分析模型求解算法的实用性。     

辽宁北票地区江沟山岩体锆石U-Pb年代学和地球化学

辽宁北票地区江沟山岩体主要岩性为二长花岗岩,属高钾钙碱性岩系.SiO₂含量高（71.4%~73.78%）,富碱并相对富Na₂O（Na₂O/K₂O平均为1.17）,Mg^#较低（平均为0.18）.岩石的铝饱和指数（A/CNK）较高（1.09~1.24）,为过铝质岩石.标准矿物中普遍出现刚玉分子（1.36~3.01）,应属S型花岗岩特点.稀土总量较低（平均为96.99×10^-6）,轻、重稀土分馏明显（（La/Yb）_N=6.27~32.88）,有中等程度的负铕异常（0.77~0.87）.在微量元素蜘蛛网图上,强烈富集大离子亲石元素（如Rb、Ba）,高场强元素（如Ti）强烈亏损.在R₁-R₂图解中,江沟山岩体投影在同碰撞环境.该岩体锆石U-Pb年龄加权平均分别为239±2 Ma和233±4 Ma,表明该岩体为三叠纪侵位.前人研究发现,本区西部有中三叠世（229.2~237.5 Ma）侵入的S型花岗岩体,认为是西伯利亚板块与华北板块碰撞的产物.本文结论与之完全一致,从而为两大板块边缘大陆岩石圈演化提供了新的依据.     

辽河三角洲地貌演化(英文)

This paper mainly analyzes the geomorphological changes of the tidal deposition in the Liaohe Estuary based on the multi-year bathymetric charts in 1990, 1996, 2002 and 2005 and Landsat TM images in 1987, 1994, 2002 and 2005. Evolution of the tidal depositional system during the past 20 years in the Liaohe River was studied on the basis of 50 boreholes drilling and 30 km shallow stratigraphic exploration from 2002 to 2005. The main tidal depositional body of the modern Liaohe River delta is located in the Shuangtaizihe Estuary. The stratum within the depth of 10 m includes tidal bank facies, tidal channel facies and neritic facies with paleo-delta facies underlying them. The sediments of tidal bank facies are mainly composed of sand and silt with siltation load and suspended load of about 50% respectively in proportion. The sediment of tidal channel facies and neritic facies is composed of clayey silt and silty clay which belongs to suspended load. The study area was a small bay between the old Daliaohe River, the old Dalinghe River and the Raoyanghe River complex delta since the Holocene to 1896. Many tidal banks formed and expanded rapidly after the Shuangtaizihe River was excavated by labor in 1896. The runoff and sediment discharge have decreased since the construction of brake at the Shuangtaizihe River in 1958.The Shuangtaizihe Estuary is in the state of deposition as a whole whose tidal bank is increasing and expanding southward, westward and northward. The maximum expansion speed is 87 to 683 m/a and the mean depositional rate is 0.189 m/a. Erosion occurred in some part of tidal bank with average erosional rate of 0.122 m/a. The tidal channel was filled up with sediment at a migration speed of 48–200 m/a. Geomorphologic changes have happened under the combined influences of runoff, ocean dynamics and human activities. The main source of sediment changes from river sediment to sediment driven by tidal current and longshore current.     

基于背景噪声的宁夏及邻区瑞利波层析成像

In this article,the vertical components of the continuous waveform data of 90 seismic stations in Ningxia and its adjacent regions recorded from January 2012 to December 2013 are used to obtain the Rayleigh surface wave group velocity dispersion images in the study area( 101°- 112°E,31°-42°N) according to the method of noise imaging,with period between 6s - 50s and resolution of 0.5°. The Yinchuan basin in the 6s - 26 s period obviously shows a low velocity anomaly,which is not uniform and has a tendency to gradually weaken; the Guanzhong Basin in 6 s-22s shows a strip of low velocity anomaly and demonstrates a transverse inhomogeneity,where velocity in the southeast is slightly faster than that in the northwest. In the 30s - 50s period it shows that in the Yinchuan graben basin and its southern area,there is a large low velocity anomaly area,which moves from northeast to southwest. It shows that between the main active tectonic zones,like mountains and basins,there are obvious geomorphologic boundaries. For example,the deep fault near Liupan Mountain is the dividing line between two large tectonic units of eastern and western of China. The inversion results have good correlation with the geological structure and the stratigraphic landform. The results are consistent with the results of artificial seismic section tomography across the basin. It provides an important basis for the dynamics of active tectonic zones and the mechanism of earthquake occurrence in this area.     

2015年尼泊尔8.1级地震前后拉萨地电场观测数据变化分析*

2015年4月25日尼泊尔8.1级强烈地震前后,拉萨地磁台(以下简称“拉萨台”)地电场观测数据出现了长时间、大幅度异常变化。在对拉萨台地电场观测条件、观测系统以及观测结果进行初步讨论的基础上,利用“能量合成累加”和“MSA功率谱分析”等数据处理方法,从“时间域”和“频率域”两个方面,对该异常变化的主要特征和演化过程进行了分析。结果显示,尼泊尔8.1级地震前后,拉萨台的地电场观测数据异常变化,经历了“趋势变化-扰动变化-发震期-恢复期”等发展阶段,以及“低频变化-高频变化-平稳变化-高频变化”等演化过程。综合分析认为,拉萨台地电场观测异常变化特征和演化过程,与相关现象和机理研究结果基本吻合,能够完整反映强烈地震孕育、发生和发展全过程,是具有一定客观性、典型性和代表性的珍贵资料。     

土热传导系数及模型的研究现状和展望

近年来,随着全球能源消耗的增加,对新能源的开发和利用日益重要。地热资源作为一种清洁环保的新能源已经开始引起广泛的关注,对岩土材料的热性质研究也逐渐受到国内外学者的重视。土的热性质包括热传导系数、热扩散系数和比热容。其中,热传导系数作为其中最重要的性质,它不仅决定了热量在土体中的传播速度和土体温度场的分布,同时也是各种地热泵、能量桩等建筑热工结构设计中需要考虑的主要参数之一。首先介绍了土热传导系数的工程背景和研究意义,描述了土中的热量传播方式和类型,阐述了热传导系数的概念,并分析了土热传导系数的各种影响因素（含水率、密度、矿物成分、温度等）。在此基础上,总结了目前国内外土热传导系数模型的研究现状,并对各个模型的优缺点进行了简要的分析和评价。最后,提出了对土传导系数及模型研究的建议和展望。     

内蒙古中东部达里湖湖岸堤记录的12.5 cal ka BP以来湖面波动过程*

内蒙古中东部位于东亚夏季风过渡区,对气候变化响应敏感。广泛发育的湖泊沉积物提供了全新世以来的环境变化的理想材料。湖岸沉积物直接记录的古水位,与高分辨率的湖心钻孔记录相结合,有助于全面认识古气候的变化历史和湖面波动的定量重建。运用AMS¹⁴C测年和GPS、DEM及1︰5万地形图等相结合的方法确定了达里湖北侧湖岸堤的年代和高程,并结合湖岸堤剖面的沉积序列指示的湖面变化过程,重建了12.5 cal ka BP以来达里湖的波动历史。12.5 cal ka BP,达里湖湖面海拔高度约为1253,m,至12.3 cal ka BP湖面经历短暂上升,至海拔1266,m左右;之后湖面下降,至全新世早期(11.2 cal ka BP),水位降至1254,m左右;随后湖面开始逐步上升,10.7 cal ka BP湖面水位稳定在1274,m左右;全新世中期湖面继续上升至某一高度(至少在1291,m)后,于全新世晚期4.8 calka BP 湖面高度降至1279,m,并于4.6 cal ka BP湖面继续下降至1275,m的高度。通过对比湖心钻孔记录的湖泊波动历史以及区域湖泊沉积记录,认为达里湖的水位波动受东亚季风活动的影响,具有区域的一致性。达里湖的水位变化较区域内的其他湖泊更为强烈,认为除了受区域气候变化的影响外,达里湖全新世晚期的湖面下降可能还与区域内强烈的构造活动和西拉木伦河溯源侵蚀导致区域水系的改变有关。