垃圾填埋场地下水监测网络可靠性评估

由于自身运行性质以及巨大的规模,垃圾填埋场成为了地下水污染的重要污染源。这些垃圾填埋场的监测井网络在探测污染羽的位置时起着至关重要的作用。本项研究介绍了一种评估垃圾填埋场地下水监测系统可靠性的方法。对几种检测系统的监测率进行了比较,提出了一个假设存在的问题。Monte-Carlo方法被用来综合评价由于地下非均质性及泄露位置而造成的不确定性。水力传导系数和渗漏位置作为用来指示用的概率密度函数的随机变量。有限差分地下水模型与随机流动的质点跟踪模型可模拟出源自垃圾填埋场的污染羽形态。分析表明,媒介的横向分布率对监测系统的可靠性有重要影响,这是因为横向分布率是控制污染物羽的主要参数。此外,监测井的数量和位置取决于媒介的各向异性和污染物泄漏的尺寸。最终可推断,习惯上采用的三梯度监测井的可靠性从对垃圾填埋场地下水污染的预防角度而言是不充分的。     

鲁西南地区石炭纪—二叠纪含煤岩系层序地层及聚煤特征

根据钻井、测井和地质等资料,对鲁西南地区石炭纪—二叠纪含煤岩系进行了层序地层学与聚煤作用研究。识别出以区域不整合面、古土壤层底面、海侵方向转换面、下切谷砂体底面为代表的4种类型的层序界面;划分出本溪组、太原组、山西组和下石盒子组中的4个三级层序,从下到上依次为SⅢ1、SⅢ2、SⅢ3及SⅢ4。通过对比研究不同层序的含煤性及煤层的发育特征后认为,形成于分流间湾沼泽环境的SⅢ3煤层发育最好,形成于潟湖与沼泽环境的SⅢ1及SⅢ2煤层发育次之,SⅢ4没有煤层发育。在同一个层序内部,泥炭聚集速率与可容空间增加速率之间的平衡状态决定了煤层的厚度,这种平衡状态保持较长时间是煤层形成的基本条件,而与泥炭聚集有关的可容空间的持续增加需要基准面的不断抬升,因此,发育较好的煤层最可能形成于海侵体系域末期,如SⅢ3的TST末期的3号煤层。     

Rock composition and origin of the Duwi Formation calcareous rocks, Upper Egypt

Upper Cretaceous phosphorite beds of the Duwi Formation, Upper Egypt, are intercalated with limestone, sandy limestone, marl, calcareous shales, and calcareous sandstone. Calcareous intercalations were subjected to field and detailed petrographic, mineralogical and geochemical investigations in order to constrain their rock composition and origin. Mineralogically, dolomite, calcite, quartz, francolite and feldspars are the non-clay minerals. Smectite, kaolinite and illite represent the clay minerals. Major and trace elements can be classified as the detrital and carbonate fractions based on their sources. The detrital fraction includes the elements that are derived from detrital sources, mainly clay minerals and quartz, such as Si, Al, Fe, Ti, K, Ba, V, Ni, Co, Cr, Zn, Cu, Zr, and Mo. The carbonate fraction includes the elements that are derived from carbonates, maily calcite and dolomite, such as Ca, Mg and Sr. Dolomite occurs as being dense, uniform, mosaic, very fine-to-fine, non-ferroan, and non-stoichiometrical, suggesting its early diagenetic formation in a near-shore oxidizing shallow marine environment. The close association and positive correlation between dolomite and smectite indicates the role of clay minerals in the formation of dolomite as a source of Mg^2＋ -rich solutions. Calcareous rocks were deposited in marine, oxidizing and weakly alkaline conditions, marking a semi-arid climatic period. The calcareous/argillaceous alternations are due to oscillations in clay/carbonate ratio.     

宝鼎盆地晚三叠世煤系层序地层与聚煤规律

运用层序地层学有关理论和方法,根据钻井、测井等资料,对四川宝鼎盆地晚三叠世大荞地组煤系进行了层序地层学与聚煤作用研究。共识别出12个层序界面,并将大荞地组划分出1个二级层序、3个三级层序和11个四级层序。垂向上,大荞地组二级层序格架下聚煤强度曲线总体呈先增强再减弱的趋势,且以高位体系域中期(盆地稳定断陷期SIII2)的聚煤作用最好。在该断陷盆地演化的早中期(SⅣ1—SⅣ5),主要煤层多发育于四级层序低位体系域、湖侵体系域早期以及高位体系域中晚期;至该盆地演化的中晚期,随着盆地基底沉降速率减缓,主要煤层逐渐向最大湖泛面附近迁移。      

沐官岛水库蓄水初期盐分运移数值模拟

沐官岛水库是一个拟建的河口海湾水库,库底为富含咸水的潮滩沉积物。这一特殊的地质及水环境条件直接关系到水库未来的水质安全和正常的调度运行,所以必须准确地确定水库水体中盐分空间分布这一关键问题。本文依据现场调查、钻探及室内实验资料,通过垂直方向线性插值技术,建立了沐官岛水库蓄水初期盐分运移准三维模型,模拟了水库蓄水初期在内源盐分释放影响下,库水盐分的演化过程。结果表明:若遇平水年开始蓄水,当蓄水至1.5m时,该层含盐量在平面上的变化范围主要在0.30~1.30g/L之间;当蓄水至4.5m时,该层含盐量在平面上的变化范围主要在0.30~1.55g/L。     

块系岩体非协调动力响应特征试验研究

岩体在块系构造状态下的动力传播存在块体和块体间软弱介质的非协调变形现象，对岩体结构的动力稳定产生重要影响。目前块系岩体的非协调动力传播响应研究尚不充分，导致不能进行有效的动力响应特征识别。通过试验对块系岩体非协调动力传播过程岩块动力响应特征进行研究，分别从动力传播速度、岩块加速度振幅衰减、岩块振动位移响应、岩块振动持续时间、块体动能显现、块体振动频域响应特性等方面对比纵波传播，给出块系岩体非协调动力传播的特征分析。通过分析可知，块系介质非协调变形运动产生的动力传播现象相比于纵波传播是一种低频低速波，并伴随着岩块的大位移运动，同时岩块振动持续时间较长，蕴含着动能与势能的相互转换过程，这些现象构成了块系岩体非协调动力传播的重要特征。该研究将为识别岩体非协调动力传播特征及块系岩体的冲击预警波动特征识别提供参考。     

Palaeogeology of the Country around Hsiatsuchang before the Chihsia Transgression

正 The area extending from the Suiyang~2 city in the north to Tuanchi~3 in the south was surveyed by the writers in 1943. Apart from 2 few scattered outcrops of Cenozoic and recent deposits, the major stratigraphical units represented in this area are the Cambrian, the Ordovician, the Silurian, the Permian, and the Triassic systems. Gaps of some importance were observed between the     

四川宝鼎盆地晚三叠世层序地层与聚煤作用

运用钻井岩心、测井及层序地层学的有关理论、方法,对位于扬子地块西缘、四川攀枝花地区的宝鼎盆地的含煤岩系进行了层序地层学与聚煤作用研究。在主要含煤段大荞地组发育12个层序界面和11个四级层序,其中在40#煤层以上地层发育层序Ⅳ到层序Ⅺ等8个四级层序。伴随着宝鼎盆地由断陷盆地(大荞地组沉积时期)向大型拗陷盆地(宝鼎组沉积时期)演化,盆地基底沉降速率减小,可容空间增加速率降低,聚煤作用在垂向上先增强再减弱。断陷盆地发育早期,聚煤作用较弱;断陷盆地发展中期(层序Ⅳ-层序Ⅷ),主要煤层多发育于低位体系域、初始湖泛面附近和高位体系域中晚期,平面上聚煤中心位于可容空间增加速率中等的三角洲平原相带;至盆地发展晚期(层序Ⅸ-层序Ⅺ),主要煤层的发育位置逐渐向四级层序最大湖泛面靠近,平面上聚煤中心向可容空间增加速率最大的盆地沉积中心迁移。     

近海型含煤岩系沉积学及层序地层学研究进展

层序地层学是近20年来发展起来的一门新的方法学科,并在聚煤作用分析中得到广泛应用。作者就近海型含煤岩系沉积学研究历史以及煤系层序地层学研究方法及有关问题进行探讨,认为近海环境的聚煤作用实际上是海平面(基准面)上升过程中发生的,同时提出煤层厚度受泥炭堆积速率与可容空间增加速率的控制：靠陆一侧冲积平原和三角洲平原沉积环境中,厚煤层主要出现在最大海泛面位置;而靠海一侧障壁-潟湖或碳酸盐岩台地沉积环境中,厚煤层主要出现在初始海泛面的位置;但就整个三级复合层序来说,层序中厚度最大、分布最广的煤层主要分布于可容空间增加速率最大的最大海泛面附近的位置。对于中国晚古生代近海型煤系中常见的“根土岩-煤-石灰岩”序列,聚煤作用发生于海相石灰岩“滞后时段”,即在海侵之后、海相石灰岩层真正沉积下来之前的时段,这一时段可容空间增加速率与泥炭堆积速率平衡,有利于聚煤作用发生。     

Parameterization of the Absorption of the H_2O Continuum,CO_2,O_2,and Other Trace Gases in the Fu-Liou Solar Radiation Program

The absorption properties of the water vapor continuum and a number of weak bands for H2O, O2, CO2, CO, N2O, CH4, and O3 in the solar spectrum are incorporated into the Fu-Liou radiation parameterization program by using the correlated k-distribution method (CKD) for the sorting of absorption lines. The overlap absorption of the H2O lines and the H2O continuum (2500-14500 cm-1) are treated by taking the two gases as a single-mixture gas in transmittance calculations. Furthermore, in order to optimize the computation efforts, CO2 and CH4 in the spectral region 2850-5250 cm-1 are taken as a new single-mixture gas as well. For overlap involving other absorption lines in the Fu-Liou spectral bands, the authors adopt the multiplication rule for transmittance computations under which the absorption spectra for two gases are assumed to be uncorrelated. Compared to the line-by-line (LBL) computation, it is shown that the errors in fluxes introduced by these two approaches within the context of the CKD method are small and less than 0.48% for the H2O line and continuum in the 2500-14500 cm-1 solar spectral region, -1% for H2O (line) H2O (continuum) CO2 CH4 in the spectral region 2850-5250 cm-1, and -1.5% for H2O (line) H2O (continuum) O2 in the 7700-14500 cm-1 spectral region. Analysis also demonstrates that the multiplication rule over a spectral interval as wide as 6800 cm-1 can produce acceptable errors with a maximum percentage value of about 2% in reference to the LBL calculation. Addition of the preceding gases increases the absorption of solar radiation under all sky conditions. For clear sky, the increase in instantaneous solar absorption is about 9%-13% (~12 W m~2) among which the H2O continuum produces the largest increase, while the contributions from O2 and CO2 rank second and third, respectively. In cloudy sky, the addition of absorption amounts to about 6-9 W m-2. The new, improved program with the incorporation of the preceding gases produces a smaller solar absorption in clouds due to the reduced solar flux reaching the cloud top.