再论煤中大分子基本结构单元演化的拼叠作用

芳构化作用和环缩合作用的传统煤化作用理论具有一定局限性,煤中基本结构单元拼叠作用是高煤级煤演化的特有机理。拼叠作用显著发生的起点位于镜质组最大反射率Ro,max为6．0％附近,大分子化学键的均裂提供了拼叠作用得以实现的微化学环境条件,其实质是一种“动力化学”过程,与氧接芳碳等有关的大量“均裂”是在短暂的煤化阶段中突然出现的,导致“拼叠作用”的显著发生具有“阶跃式”特征,是造成高煤级煤中期到后期阶段大分子基本结构单元急剧增大的根本原因和主要地球化学机理。     

多工况下汉源二蛮山滑坡机理数值模拟

利用FLAC3D软件对四川省雅安市汉源县二蛮山滑坡坡体进行建模,模拟降雨滑坡过程,并进行应力应变特征及稳定性计算分析,从而为深入研究地震及降雨诱发再次滑坡及防灾减灾提供可靠依据。研究中假设地震工况,对边坡进行详细的动力分析,得到了各监测点动力特征曲线;通过降雨工况下坡体稳定性系数分析得到了不同强度折减安全系数。研究结果表明,滑源区相对特殊的地形条件和地质构造以及不利的结构面组合是滑坡的基础;前期强降雨期间饱水加载以及大量雨水沿斜沟张裂结构面的下渗软化作用,是诱发滑坡发生的关键因素。      

四川汶川地震断裂带科学钻探2号孔（WFSD-2）岩性特征和断裂带的结构

以WFSD-2钻孔岩心为研究对象,通过详细的岩心编录和岩石学、构造地质学等研究,识别出该钻孔岩心具有6段岩性,从上向下依次为彭灌杂岩（0-599.31m）、三叠系须家河组二段（599.31-1211.49m）、彭灌杂岩（1211.49-1679.51m）、三叠系须家河组三段（1679.51-1715.48m）、彭灌杂岩（1715.48-2081.47m）、三叠系须家河组四段（2081.47-2283.56m）。彭灌杂岩主要以花岗岩和火山岩为主,三叠系须家河组沉积岩以砂岩、粉砂岩、泥岩、页岩、煤层（线）和砾岩为主。3套彭灌杂岩与三叠系须家河组沉积岩重复出现,时代较老的岩性段逆冲覆盖在新的地层之上,表明龙门山构造带由一系列逆冲岩片叠置而成。岩心中断裂岩较为发育,主要为断层角砾岩、碎裂岩和断层泥,反映出脆性变形作用的特点。通过对断裂岩的统计分析,厘定了20余条产状不同、规模不等的次级断裂带,断裂带宽度和断裂密度峰值显示FZ600、FZ720、FZ782、FZ817、FZ922、FZ951、FZ1449、FZ1681、FZ2082为主要断裂带,其中FZ1681系规模最大的一条断裂。依据断裂岩的组合特征可以将岩心中断裂带的结构以断层泥为核部划分为两大类：对称型断裂带和不对称型断裂带。根据地表破裂带、WFSD-1钻孔岩心中主滑移带位置的几何关系、岩性分层等因素,可推断汶川地震主滑移带应位于FZ1134、FZ1449或FZ1681之中,同时也暗示该地区经常发生类似汶川地震的大地震活动。研究表明,龙门山地区经历了强烈的构造缩短和快速隆升作用,暗示龙门山地区构造活动非常强烈。     

塔里木盆地中—下奥陶统层序地层研究

运用地震、测井等手段,结合岩石学、生物地层学地层对比方法,将塔里木盆地中—下奥陶统层序划分为1个二级层序(SSQ6),4个三级层序:SQ1、SQ2、SQ3、SQ4。对层序地层、沉积相特征研究发现,构造运动、海平面升降和古气候变化为塔里木盆地中—下奥陶统层序发育主要控制因素。     

Wenchuan Earthquake： Way of thinking is changed

On 12 May, 2008, at 14：28：04 local time, an Ms 8.0 earthquake struck the Wenchuan County, Sichuan Province, in southwest China （Figure 1）. This quake left about 70,000 people dead, 18,000 missing and over 370,000 injured. In the 75 days after the main shock, 20,000 aftershocks were recorded, which included 241 with Ms≥4.0, 205 with 4.0≤M≤4.9, 30 with 5.0≤Ms≤5.9, and 6 with Ms≥6.0. The largest aftershock took place 13 days after the main shock, in Qingchuan County, 110 km northeast of the epicenter of the quake （Chen, 2008）. The losses from the quaketriggered geological disasters accounted for over a third of the total quake losses, which is extremely rare in the history of earthquake disasters. Secondary disasters, such as landslides, rockslides, landfalls, debris flows, etc., were widely distributed. Large numbers of buildings collapsed, including ones with steel reinforcing in the area of the epicenter. Infrastructure was badly damaged. In many areas, communications, and power and water supplies were cut off. The earthquake left over 35 large quake-dammed lakes, which threatened further disasters in the catchment areas.     

Composition and source identification of polycyclic aromatic hydrocarbons in mangrove sediments of Peninsular Malaysia: indication of anthropogenic input

This is a comprehensive study of the composition, origin and sources of specific polycyclic aromatic hydrocarbons (PAHs) in sediments of mangrove estuary in the western part of Peninsular Malaysia. Mangrove sediments were analyzed for 17 PAHs by gas chromatography–mass spectrometry. Total PAH concentrations in the sediments ranged from 20 to 112 ng/g on a dry-weight basis. High molecular weight PAHs were abundant in the sediments. Parent PAH ratios revealed that pyrogenic input has important contribution to the sedimentary PAHs. Ratios of alkylated PAHs indicate that the sedimentary PAHs were influenced by petrogenic PAHs, which implies that petrogenic input has contribution to the sedimentary PAHs but that it is not a major factor in distribution of PAHs within the estuary. Combustion-derived PAHs show a positive and very strong correlation with total PAHs (R ² = 0.926, p < 0.05). Total methylphenanthrenes show very weak correlation with total PAHs (R ² = 0.0928, p < 0.05). The PAH concentrations were found to increase with distance from the upstream of the estuary to the coastal area of the Straits of Malacca. For the assessment of sediment contamination using biological thresholds, none of the individual studied PAH compounds exceeded the values of the effect range low–effect range median guideline and the threshold effects level–probable effects level guideline. This study demonstrates that the sediments of the mangrove ecosystem facing the Straits of Malacca and Sumatra are influenced by anthropogenic PAH inputs as a result of human activities such as biomass burning, vehicle emissions and boating activities.     

Is Prediction of Future Landslides Possible with a GIS?

This contribution explores a strategy for landslide hazard zonation inwhich layers of spatial data are used to represent typical settings inwhich given dynamic types of landslides are likely to occur. Theconcepts of assessment and prediction are defined to focus on therepresentation of future hazardous events and in particular on themyths that often provide obstacles in the application of quantitativemethods. The prediction rate curves for different applications describethe support provided by the different data layers in experiments inwhich the typical setting of hazardous events is approximated bystatistically integrating the spatial information.     

低幅值小应变振动下土体弹性刚度的非线性特征与表述方法

随着高速铁路建设的兴起,轨道以及沿线附近建筑物承受低幅值小应变振动荷载的作用。对于小应变振动下土体的有限元计算,如何确定连接应力和应变之间纽带的刚度张量E,对于建立合理的预测模型来分析高速铁路轨道以及沿线建筑物的沉降变形至关重要。低幅值小应变振动下剪切模量G和阻尼比D随剪应变幅值的变化是反映土体刚度及阻尼特征最重要的两个参数。通过共振柱试验发现,振动荷载作用下土体的剪切模量G必须通过振动应变幅值和固结围压共同来确定,即使在小应变（剪应变幅值10-6相似文献   

Comparison of the Ordovician-Carboniferous Boundary Between Korea and NE China: Implications for Correlation and Tectonic Evolution

There is a great hiatus between Ordovician and Carboniferous strata in the Northeast China and Korean Peninsula. In order to understand geology and tectonic evolution, and to find out the similarities and differences in both regions, two sections in the Western Hill near Beijing in NE China and several sections in the Korean Peninsula were selected to examine their geologic boundaries between Lower and Upper Paleozoic strata to compare their characteristic features. At four sites in the two sections in the Western Hill near Beijing were examined their contact relations. The Hui Yu section is the same horizon where one site is top of a quarry hill and the other of down hill. Mid-Carboniferous Qingshuijian Formation rests on the Ordovician Majiagou Formation. Limestone beds are more commonly intercalated with shale and sandstone at site 2 of the Hui Yu section, while at site 1, conglomerate beds are dominant. Site 1 of the Se Shu Fen section shows eroded and concealed karst topography and conglomerate beds are intercalated within shale beds. Silurian and Devonian strata are absent in these areas. In the Korean Peninsula, most O-C contacts occur between Ordovician limestone formation and Carboniferous strata, although Silurian strata occur beneath the Carboniferous strata in the Jeongseon area and Pyeongnam Basin. Most contact relations are parallel unconformity and angular unconformity is rarely seen. The O-C relations in both regions are similar to each other, and these indicate that the Korean Peninsula was located near or belonged to the Sino-Korean paraplatform during Paleozoic time.     

二红洼镁铁-超镁铁杂岩体特征及成因

新疆哈密二红洼镁铁-超镁铁杂岩体地表分南北两个岩体,深部可能连为一体,可划分为两个侵入期、四个岩相.第一侵入期构成岩体的主体部分,分异良好,由重力结晶分异形成自橄揽岩相、橄榄辉长岩相向含石英苏长辉长岩相的分异趋势,基性程度依次降低.岩浆多次贯入使得纵向上橄榄岩相和橄榄辉长岩相重复出现.第二侵入期辉长苏长岩相分异程度低,岩性稳定,为岩浆快速冷凝的产物.岩浆属于拉斑玄武岩系列,发生过金属硫化物熔离,有利于铜镍硫化物成矿.