长江中下游湖泊沉积物铅污染记录——以洪湖、固城湖和太湖为例

2002～2005年在长江中下游的洪湖、固城湖和太湖分别采集了沉积物柱样钻孔,测定了总有机碳（TOC）和金属元素包括Pb,Al,Fe,Ti等,并采用²¹⁰Pb和¹³⁷Cs进行了近代沉积物定年。研究结果表明,洪湖钻孔平均沉积速率为0.15cm/a,固城湖平均沉积速率在0.067cm/a,太湖平均沉积速率为0.35～0.41cm/a。根据湖泊沉积物中铅元素与参考元素（Al,Fe和Ti）浓度和TOC的相关关系建立了回归方程,线性关系极显著（p<0.001）。根据回归方程获取了钻孔中铅的背景值变化,研究表明近代沉积物中金属铅不仅仅来源于自然的作用,而人类活动导致铅的累积发生时间都在20世纪70年代,从一个侧面也说明利用沉积物铅含量变化进行断代存在可能性。对太湖钻孔而言,其污染程度要高于洪湖和固城湖。研究结果表明近30年来洪湖和固城湖人为造成湖泊沉积物铅累积量在不断增加,其沉积物铅污染有进一步加重的趋势,应受到科学家和管理部门的关注。     

Numerical Modelling of Dissolving and Driving Exploitation of Potash Salt in the Qarhan Playa——A Coupled Model of Reactive olute Transport and Chemical Equilibrium in a Multi-component Underground Brine System

Firstly, the macroscopic chemical equilibrium state of a series of chemical reactions between intercrystal brine and its media salt layer (salt deposit) in Qarhan Salt Lake was studied by using the Pitzer theory. The concept of macroscopic solubility product and its relation with accumulated ore dissolving ratio were presented, which are used in the numerical model of dissolving and driving exploitation of potassium salt in Qarhan Salt Lake. And secondly, with a model forming idea oftransport model for reacting solutes in the multi-component fresh groundwater system in porous media being a reference, a two-dimensional transport model coupled with a series of chemical reactions in a multi-component brine porous system (salt deposits) was developed by using the Pitzer theory.Meanwhile, the model was applied to model potassium/magnesium transport in Qarhan Salt Lake in order to study the transfer law of solid and liquid phases in the dissolving and driving process and to design the optimal injection/abstraction strategy for dissolving and capturing maximum Potassium/Magnesium in the mining of salt deposits in Qarhan Salt Lake.     

Numerical Modelling of Dissolving and Driving Exploitation of Potash Salt in the Qarhan Piaya——A Coupled Model of Reactive Solute Transport and Chemical Equilibrium in a Multi-component Underground Brine System

Firstly,the macroscopic chemical equilibrium state of a series of chemical reactions between intercrystal brine and its media salt layer (salt deposit) in Qarhan Salt Lake was studied by using the Pitzer theory.The concept of macroscopic solubility product and its relation with accumulated ore dissolving ratio were presented,which are used in the numerical model of dissolving and driving exploitation of potassium salt in Qarhan Salt Lake.And secondly,with a model forming idea of transport model for reacting solutes in the multi-component fresh groundwater system in porous media being a reference,a two-dimensional transport model coupled with a series of chemical reactions in a multi-component brine porous system (salt deposits) was developed by using the Pitzer theory. Meanwhile,the model was applied to model potassium/magnesium transport in Qarban Salt Lake in order to study the transfer law of solid and liquid phases in the dissolving and driving process and to design the optimal injection/abstraction strategy for dissolving and capturing maximum Potassium/ Magnesium in the mining of salt deposits in Qarban Salt Lake.     

新疆坎儿井现状及其发展

简述了新疆坎儿井的构成、特点、研究意义,分析了坎儿井衰退状况及其原因,列举了已进行的坎儿井保护工作,提出了坎儿井于枯断流的综合治理对策及今后的发展方向。     

浅析宁芜北段铜矿地质特征、找矿前景与方向

在综合分析区域地质背景、铜矿床基本特征、主要控矿因素、找矿标志的前提下,对该区寻找铜矿的前景提出了看法,指出宁芜北段今后寻找铜矿应侧重斑岩型铜矿,提出了皇姑山等地区可作为今后寻找铜矿的重点地段及今后找矿的工作建议。     

太湖流域土壤重金属元素污染历史的重建:以Pb、Cd为例

太湖是位于长江下游的一个大型浅水湖泊,通过对4个代表太湖不同沉积环境的湖底沉积剖面的137Cs和210Pb沉积定年,重建太湖湖底沉积物和太湖来水流域土壤Cd、Pb的污染历史。结果显示:1980年以前,太湖底积物中Cd、Pb含量与流域内的自然背景含量相当,1980年以后,湖底沉积物中的Cd、Pb含量显著增高,这与我国大规模工业化进程的起始时间基本一致,推测工业化进程是湖底沉积物中Cd、Pb含量增加的主要原因。1900年以来太湖湖底沉积物中累积含有Cd和Pb分别为146t和25980t,其中苕溪来水提供的Cd和Pb分别为40t、6777t,宜溧河来水提供的Cd、Pb分别为36t、6023t,其他来水(洮、滆、运河)提供的Cd、Pb分别为71t、13179t,其他来水是太湖Cd、Pd累积的主要输入途径。Cd、Pb累积的高峰期为20世纪80—90年代,1980年以来,运河来水Cd、Pb的输出通量为28.26t、3419t;苕溪流域Cd、Pb的输出总量分别为13.70t、1585t,其中人为源的Cd、Pb为8.90t、610t,人为源输出的Cd、Pb通量占总输出量的64.96%和38.47%;宜溧河流域Cd、Pb的输出总量分别为10.09t、1063t,人为源的Cd、Pb分别6.96t和500t,人为源输出的Cd、Pb通量占总输出量的68.68%和47.08%,表明太湖流域人类活动所导致的Cd已超过自然剥蚀过程,因此削减工业化进程中的Cd、Pb排放总量,控制太湖运河来水的输出通量是改善太湖底积物Cd、Pb环境质量的关键措施。     

松辽盆地白垩纪湖泊水体温度与古气候温度估算

湖泊沉积物沉积的第一场所是湖底,湖底温度的高低影响沉积有机质的保存,也影响湖底下部地层的温度。了解古水体温度尤其是古水底温度情况成为评估松辽盆地白垩系生物气勘探前景的必要研究内容之一。根据已有的古气候研究成果与现今气候对比,得出白垩纪松辽盆地年平均气温约为14~24℃。再根据水库温度的计算方法和利用已有的古纬度及古水深的研究成果计算得出,白垩纪松辽盆地古湖盆水体表面温度为17~25℃;水深大于20 m的深湖区,水底温度为6.2~12.5℃;湖底最深处温度为4.0~11.3℃;青山口组和嫩江组沉积时期,湖水分层明显,湖底温度季节性变化很小且温度较低,约为8℃。湖底的低温对松辽盆地白垩纪生物气勘探是有利的。     

GIS中最佳遍历分析算法与实现

首先介绍了地理信息系统（GIS）网络分析的发展概况;其次在已有GIS最佳遍历分析存在问题的基础上,提出了一种最佳多路遍历分析算法。并在ArcEngine环境下,以某县交通网为例,利用C#.net及ArcEngine二次开发类库实现了其最佳多路灾情巡视路线分析。算法适用范围广,可以推广到很多同类的地理网络问题。     

临港新城地质特征及其对新城规划与建设的影响分析

结合临港新城三维地质调查所取得的成果,分析了该城区地质特征及对新城建设的影响,为新城规划建设提供科学依据和服务。     

Dynamics of the mid-ocean ridge plate boundary: Recent observations and theory

The global mid-ocean ridge system is one of the most active plate boundaries on the earth and understanding the dynamic processes at this plate boundary is one of the most important problems in geodynamics. In this paper I present recent results of several aspects of mid-ocean ridge studies concerning the dynamics of oceanic lithosphere at these diverging plate boundaries. I show that the observed rift valley to no-rift valley transition (globally due to the increase of spreading rate or locally due to the crustal thickness variations and/or thermal anomalies) can be explained by the strong temperature dependence of the power law rheology of the oceanic lithosphere, and most importantly, by the difference in the rheological behavior of the oceanic crust from the underlying mantle. The effect of this weaker lower crust on ridge dynamics is mainly influenced by spreading rate and crustal thickness variations. The accumulated strain pattern from a recently developed lens model, based on recent seismic observations, was proposed as an appealing mechanism for the observed gabbro layering sequence in the Oman Ophiolite. It is now known that the mid-ocean ridges at all spreading rates are offset into individual spreading segments by both transform and nontransform discontinuities. The tectonics of ridge segmentation are also spreading-rate dependent: the slow-spreading Mid-Atlantic Ridge is characterized by distinct bulls-eye shaped gravity lows, suggesting large along-axis variations in melt production and crustal thickness, whereas the fast-spreading East-Pacific Rise is associated with much smaller along-axis variations. These spreading-rate dependent changes have been attributed to a fundamental differences in ridge segmentation mechanisms and mantle upwelling at mid-ocean ridges: the mantle upwelling may be intrinsically plume-like (3-D) beneath a slow-spreading ridge but more sheet-like (2-D) beneath a fast-spreading ridge.