松辽盆地白垩系浅水湖泊三角洲沉积微相研究——以大庆杏树岗油田杏三区东部葡Ⅰ1-3小层为例

根据密井网测井、录井以及其它分析化验资料,结合区域地质背景,对松辽盆地杏树岗油田杏三区东部白垩系姚家组一段葡萄花Ⅰ组油层1-3小层(葡Ⅰ1-3小层)沉积微相类型、特征、组合模式和不同地质时期沉积微相平面展布特征及其演化规律进行系统的研究。结果表明,葡Ⅰ1-3小层为浅水湖泊三角洲沉积,主要发育三角洲分流平原和三角洲内前缘2种沉积亚相,含11种沉积微相,具有不同的沉积特征和测井相模式;利用自然电位曲线幅变值和砂体厚度,有效识别天然堤、水上决口沉积、溢岸薄层砂3种有成因联系、测井曲线形态类似的沉积微相;进一步根据各沉积微相的测井曲线形态组合、沉积成因及沉积作用的不同,总结出7种沉积微相组合模式。葡Ⅰ1-3小层沉积演化经历了早期湖退、中期稳定、晚期湖侵3个阶段,不同时期的沉积特征、沉积微相展布各异,总体表现出湖盆发育规模由大变小,再变大,骨架砂体厚度和理想钻遇率逐渐减小的特点。     

Successional stages of biological soil crusts and their microstructure variability in Shapotou region (China)

In order to investigate succession of biological soil crusts (BSCs) and their microstructure variability, we conducted this work in Shapotou revegetation region at the southeast edge of Tengger Deser. The results showed that BSCs generally succeeded as a pathway of “Algae crusts, algae–lichen crusts, lichen crusts, lichen–moss crusts and moss crusts”. Occasionally mosses directly occurred on algae crusts, and BSCs succeeded from algae crusts to moss crusts. Crust vertical stratification was a common phenomenon, from top to bottom an inorganic layer, algae-dense layer and algae-sparse layer were divided in algae crusts; a thallus layer, rhizoid layer and sub-rhizoid layer in lichen crusts; a “stem-leaf” layer, rhizoid layer and sub-rhizoid layer in moss crusts, respectively. The main crust binding organisms varied from filamental cyanobacteria (dominated by Microcoleus) in algae crusts to lichen rhizoids, free-living cyanobacterial filaments and fungal hyphaes in lichen crusts, and to moss rhizoids and fungal hyphaes in moss crusts. The dominant phototrophic organisms varied from Microcoleus (algae) in algae crusts to Collema (lichens) in lichen crusts, and to Bryum (or Didymodon and Tortula; mosses) in moss crusts. Total phototrophic biomass increased while the free-living algal biomass decreased with the succession of BSCs. In addition, exopolysaccharides and fine particles accumulated in the course of development and succession of BSCs, all of which lead to a gradual increase in crust thickness and porosity, while decrease in the bulk density.     

白垩纪快速气候变化研究新进展——温室世界中的冰川证据

白垩纪被认为是两极无冰的典型温室气候时期,但近年来对于白垩纪存在短暂冰川甚至是极地冰盖的猜想引起了越来越多的关注。根据前人提出的冰川或气候变冷证据,如冰川遗迹、全球海平面快速下降事件以及δ18O正偏事件等,总结了白垩纪可能存在冰川的时期,包括Berriasian Valanginian之间、Valanginian晚期、Barremiana期、Aptian Albian之交、Albian Cenomanian之交、Cenomanian中期和末期、Turonian中期、Coniacian中期、Santonian早期、Campanian晚期、Campanian Maastrichtian之交和Maastrichtian末期等。对这些证据的有效性进行详细的讨论,同时也对白垩纪冰川的可能成因进行探讨。笔者认为,白垩纪即便存在冰川,也是小规模、短暂地存在,因此,精确的年代学约束是进行白垩纪冰川研究的前提;米兰科维奇旋回控制下的气候波动是白垩纪形成短暂冰川的可能成因。     

有色示踪剂模拟槽实验图像分析法

图像分析法是处理有色示踪剂模拟槽实验结果的常用方法之一。本文以食用亮蓝为示踪剂,从污染物的检测精度和污染羽描绘的准确度两个方面将图像分析法与传统取样法进行对比,并利用Matlab编程对模拟槽内的污染物贮存质量进行定量计算。结果表明,与传统取样法结果相比：图像分析法的检测精度可提高1个数量级;污染羽的描绘准确度至少可提高3%左右,在实验所设置的非均质条件下可提高17%左右。利用自行编制的Matlab程序对本实验模拟槽内贮存亮蓝质量进行计算可得,当剖分格数为3 700²（1 369万）时,亮蓝贮存质量的计算值最接近实测值,最小误差仅为0.5%。综合来讲,图像分析法是一种准确度高、空间分辨率高的信息采集和处理手段,可实现对非均质地层中有色示踪剂运移过程更为精细的描述。     

Adsorption characteristics of perchloroethylene in natural sandy materials with low organic carbon content

Laboratory batch tests were conducted to investigate the sorption isotherms and sorption kinetics of the chlorinated hydrocarbon perchloroethylene (PCE) in five natural sandy materials with an organic carbon content (f _oc) in the range 0.080–0.540%. The amended non-linear dual-mode model can describe the sorption isotherms in materials with f _oc in the range 0.080–0.090%. For a sample with a much higher f _oc of 0.54%, the absorption isotherm was found to fit a linear model. These results may indicate that organic carbon is not the main factor influencing the sorption isotherm. The sorption kinetics of PCE in samples with f _oc in the range 0.080–0.090% are not first-order and are different from those observed in the samples with higher f _oc. The sorption process in the materials with lower f _oc involves fast sorption, fast desorption and an equilibrium stage. The results may imply that the factors affecting sorption kinetics of PCE in low f _oc media are pore filling and capillary condensation rather than organic carbon content.     

Land subsidence caused by groundwater exploitation in Suzhou City,China

Suzhou City, located at the lower reaches of the Yangtze River in southeastern Jiangsu Province, is one of the few cities in China which suffer from severe ground settlement. A research project was carried out to investigate this problem. Geological and hydrogeological studies show that there is a multi-layered aquifer system with three distinct, soft mud layers of marine and lagoonal origins. An examination of historical records of groundwater extraction, water levels, and ground settlement shows that the ground subsidence is associated with the continuously increasing groundwater extraction in the deep, confined aquifer. It is believed that the consolidation of the soft mud layers, especially the third layer which is thick and close to the main pumped aquifer, contributes to the ground settlement. A three-dimensional finite difference numerical model representing the multi-layered aquifer system was developed to study the ground settlement in response to groundwater extraction. By calibrating the model with both the measured groundwater level and ground settlement, the aquifer parameters were estimated. The model outputs fit reasonably well with the observed results, which indicates that the numerical model can reproduce the dynamic processes of both groundwater flow and soil consolidation. The hydraulic conductivity of the third mud layer near the center of the ground settlement has been reduced by over 30% in the last 14 years. The gradual deterioration in the hydraulic conductivity of the mud may have significant adverse effect on the sustainable groundwater resource of the deep confined aquifer, since the recharge from the shallow aquifers through the mud layer is the only source of water to the deep aquifer. An analysis of the spatial distributions of groundwater drawdown and ground settlement shows that the area with maximum drawdown is not necessarily the area with maximum ground settlement due to the occurrence of the soft mud layer. A simple reallocation in pumping rates on the basis of the spatial distribution of the thick mud layer could significantly reduce the ground settlement. Electronic Publication     

电偶源瞬变电磁测深研究(四)--瞬变电磁测深视电阻率

给出了由电偶源垂直磁场Ｈｚ（ｔ）计算全区（期）视电阻率的数值计算方法;将时间范围扩展到几十秒,以满足大偏移距（ｒ）探测大深度的需要。模拟计算结果显示,全区视电阻率能清晰地反映地电断面的结构,有助于定性定量解释     

新矿物—彭志忠石的发现及研究

彭志忠石产于湖南安化白钨矿区,是一种富含镁、锡、铝的复杂氧化物。矿物为浅黄褐色、浅黄色,少量无色,晶体呈六方板状。晶体化学式为:(Mg,Zn,Fe,Al)_4(Sn,Fe)_2(Al,□)_(10)O_(22)(OH)_2,空间群P_3ml,a=5.692(5)A,c=13.78(2)A,V=386.7A~3,Z=1。D=4.22(3)g/cm~3,H≥8,一轴正晶,ω=1.802(2),ε=1.814(2)。     

赣北红土区工程堆积体坡面水动力特性

为探明锥状工程堆积体坡面薄层水流剥蚀率与水力要素之间的关系, 室内模拟赣北红土区散乱锥状工程堆积体。通过人工降雨试验, 设计4种降雨强度(1.0~2.5mm/min)和3种砾石含量(10%~30%)完全组合。采用灰色关联度分析法, 评估坡面水力参数与土壤剥蚀率之间的关联度。结果表明:① 在试验条件下, 坡面水流功率与土壤剥蚀率呈幂函数关系;② 当堆积体砾石含量一定时, 以降雨强度为变量能反映堆积体坡面水力参数与土壤剥蚀率之间的关联度;③ 当降雨强度一定时, 大雨强下(≥1.5mm/min)堆积体砾石含量不宜作为灰色关联度分析的变量。综上所述, 水流功率是描述赣北红土区锥状工程堆积体侵蚀过程的最佳水力参数, 可用于建立堆积体侵蚀物理模型。     

Texture Segmentation Based on Image Model and Neural Network

INTRODUCTIoNImagetextureanalysisisanimportantpartofresearchin-tocomputervision.Forobjectidentificationandunderstand-ing,textureanalysisisthebasisoftheresearchwork.Ingeneral,texturecanberegardedasakindofstructurethatconsistsofmanytextureelementsorpatternswhicharemoreorlesssimilar,i.e.,primitivesthatformtexturesandspatialdependenceorinteractionbetweentheprimitives.Ex-tensiveresearchhasbeendoneintextureanalysis,andrefer-ence(Haralick,l979)hasmadeathoroughsurvey.Amongthesetextureanalysismetho…