北京市生产铁矿山环境问题及其治理方法

铁矿是主要矿产之一,也是北京市允许开采矿种,矿山生产过程中,部分矿山重效益,轻治理,造成矿山环境质量较差,本文重点分析了在生产铁矿山的主要环境问题及工程治理方法,为铁矿山环境质量的评价及环境治理提供参考。     

利用地震资料进行古地形恢复方法研究及应用

在讨论分析地质方法进行古地形恢复方法的基础上,研究了利用地震资料进行古地形恢复的技术方法。针对古地形恢复的几个技术关键问题:等时基准面的选取、压实校正系数的求取及差异构造校正进行讨论分析。综合利用各种基本地质成果,同时结合古构造、现今构造特点等,确定出研究区背景校正经验系数为0.2。就研究的方法对实际研究区目的层段进行了古地形的恢复。     

一种基于先验知识约束的图像盲解卷积恢复算法

在对现存的图像盲解卷积恢复算法进行阐述的基础上,介绍了一种根据概率统计理论推导的极大似然图像恢复算法。该算法通过用共轭梯度法对一个误差函数进行最小化来实现。并且在运算的过程中,加入了一些先验知识,如非负性和有限支持域等约束。     

转轮式全热交换器的节能特性及无交叉污染化研究

由于全热交换器可以同时回收空调回风空气所含有显热和潜热，作为热回收设备被广泛应用于楼宇空调新风换气系统。本文结合实例对转轮式全热交换器的节能特性及经济效益进行了分析。并在剖析了现行全热交换器发生交叉污染之机理的基础上，对转轮式全热交换器无交叉污染化进行了实验研究。     

黄河下游断流对傍河水源地影响的研究

保持黄河不断流是傍河水源地存在的必要条件,黄河频繁的断流威胁傍河开采水源地的稳定性。本文建立了黄河下游影响带地下水系统模拟模型,模拟预测黄河下游在断流和恢复过流条件下,傍河开采时黄河侧渗量的变化趋势及傍河开采水源地地下水的演变趋势。研究表明:断流条件下,因傍河水源地开采而激发的黄河侧渗补给量增加幅度达28．4％-126．4％;小浪底水库运行对于傍河水源地实现稳定开采具有重要意义。     

Short term validated geochemical model of CO2 sequestration

In this work we present a new approach to modeling the effects of CO2 sequestration that was tested in the Weyburn test site. The Weyburn oil-pull is recovered from Midale Beds （at 1300-1500 m depth）. This formation consists of Mississippian shallow marine evaporific carbonates that can be divided into two units： （1） the dolomific ＂Marly＂ and ii） the underlying calcitic ＂Vuggy＇, sealed by an anhydrite cap-rock. Presently, about 3 billions mc of supercrifical CO2 have been injected into the ＂Phase Al＂ injection area. The aim of our model is to reconstruct （1） the chemical composition of the reservoir; （2） the geochemical evolution of the reservoir with time as CO2 is injected and （3） the boundary conditions. The geochemical modeling was performed by using the code PRHEEQC （V2.11） software package. The ＂primitive brine＂ composition was calculated on the basis of the chemical equilibriums among the various phases, assuming reservoir equilibrium conditions for the mineral assemblage with respect to a Na-Cl （Cl/Na= 1.2） water, at T of 62℃ and P of 150 bars via thermodynamic corrections to the code database. A comparison between the chemical composition of the ＂primitive brine＂ and that analytically determined on water samples collected before the CO2 injection shows an agreement within 10%. Furthermore, we computed the kinetic evolution of the reservoir by considering the local equilibrium and the kinetically controlled reactions while taking it into account the CO2 injected during four years of monitoring. The calculated chemical composition after CO2 injection is consistent with the analytical data of samples collected in 2004, with the exception of calcium and magnesium contents.     

Acidification and metal contamination in Whitepine Lake (Sudbury,Canada): a paleolimnological perspective

Diatom and chrysophyte assemblages from a sediment core from Whitepine Lake were examined to infer changes in lakewater pH, nickel and aluminum concentrations since pre-industrial times, and to help determine the cause of the virtual extirpation of the lake trout population from the lake during the 1960s and 1970s. Our study indicates that acidification started in the 1920s, and that the maximum inferred pH decline (from 6.2 to 5.8) occurred between 1960 and 1970, coincident with the peak in metal mining and smelting activity in the Sudbury basin. Lakewater [Al] and [Ni], as inferred from our diatom transfer functions, increased. It appears that in addition to the pH decline, elevated [Al] may have played an important role in the decline of lake trout from Whitepine Lake in the 1960s and 1970s. Diatom-inferred lakewater pH and [Ni] have recovered slightly in the recent sediments, which coincides with reductions in emissions that have occurred since the mid-1970s.     

JPL行星历表的发展及比较

基于DE405、DE421、DE430、DE440星历,计算各大行星在地球质心及太阳系质心惯性系中的位置,比较其他星历相对于DE440星历的行星位置精度。分析讨论各历表下月球的地心位置和速度精度,以及历表对于月球探测器的位置和速度从月心惯性系转为月固系的影响,并给出使用建议。结果表明,各大行星由于受观测数据等因素影响,位置精度差异较大,跨度从m级到10⁶ m量级。对于行星的位置精度,DE421和DE430相对于DE405有1~2个量级的提高,DE430相对于DE421提高50%。DE405历表的月球地心位置、速度精度分别为7 m和0.02 mm/s,DE421历表分别为1.5 m和0.004 mm/s,DE430历表分别为1.3 m和0.003 5 mm/s。对于星历用于月球探测器从月惯系转为月固系产生的坐标和速度误差,DE405分别为30 m和3 cm/s,DE421分别为1.3 m和1.2 mm/s,DE430分别为1 m和0.9 mm/s。历表对于月球坐标系转换的影响为m级。对于月球探测器导航及相关任务,推荐使用DE430或DE440行星历表。     

珊瑚礁地层钻探取心技术研究及应用

人工吹填珊瑚岛礁地层结构比较特殊,以珊瑚砂和珊瑚碎屑为主,取心和成孔难度较大。以南海某岛礁地质钻探取心工程实践为例,针对地层岩性特点,采用一系列对应技术措施：上部松散或弱胶结砂砾层采取跟管钻进和无水干钻取心技术;礁灰岩全漏失地层设计了一套掏砂钻具进行掏砂,确保井眼干净;软硬互层采用超前侧喷钻头;粉砂质地层采取小口径钻具无水干钻取心技术等。该技术在18个钻孔实施中取得了良好的效果,可为后续珊瑚礁地层钻探取心提供借鉴。