基于环境星HJ1B数据反演大亚湾海表温度的三种算法

利用大亚湾2011年2月10日一景环境星HJ₁B热红外遥感影像,通过MODTRAN计算得到大气上、下行辐射和大气透过率,再运用经验公式计算星下辐亮度,分别用大气辐射传输方程模型法、覃志豪单窗算法和Jimenez-Munoz&Sobrino单通道算法反演大亚湾地区海表温度。将三种方法反演的结果与MODIS海表温度对比,其中覃志豪普适性单窗算法反演的海表温度与MODIS海表温度一致性最好,获得的精度较高,RTM算法与覃志豪单窗反演的结果平均误差在0.7K左右。     

A combined method to predict the long-term settlements of roads on soft soil under cyclic traffic loadings

In order to investigate the mechanism of the long-term settlement of road on the soft soil, an in situ measurement of a highway in southeast China was conducted during both the construction and post-construction stage. In the theoretical analysis, the long-term settlement of the pavement on thick soft soils was divided into three main components: the consolidation settlement, the creep deformation and the traffic load-induced deformation. The equivalent time line model based on the viscous–elastic–plastic theory was adopted to simulate the road settlement caused by the consolidation and creep of the subsoil. A cyclic strain accumulation model, which was obtained from laboratory tests of soil elements, was adopted to consider the road settlement induced by cyclic traffic loadings. A pavement dynamic response model was used to calculate the dynamic stresses in the subsoil generated by moving traffic loads when the road was open to service. It was found that the equivalent time line model combined with the cyclic strain accumulation model could predict the road settlement accurately at both the construction and post-construction stage. Numerical results showed that the traffic speed had limited effect on the post-construction road settlements for the speed range considered. The post-construction settlement of the road, mainly composed of the traffic-induced settlement and soil creep deformation, could be reduced significantly by increasing the embankment surcharge during the construction stage. The creep component accounted for over 10% of the total post-construction settlement, while the percentage of the creep deformation in total post-construction settlement decreased rapidly as the embankment surcharge increased.     

辽河大民屯凹陷中央构造带太古宇变质岩储层岩性特征分析

综合分析录井、测井、地震、岩心与分析化验等资料,对大民屯凹陷中央构造带太古宇变质岩储层岩性类型、空间分布、岩性对储层的控制作用进行了研究。研究认为：本区太古宇变质岩岩性分为三大类18种,主要有混合花岗岩、混合片麻岩、混合岩、角闪斜长片麻岩、浅粒岩、角闪岩、变粒岩,夹丰富不均一的基性脉岩和碎裂岩。有效储层岩性为碎裂化混合花岗岩与碎裂化变粒岩、浅粒岩、片麻岩;变质岩在垂向上（由下至上）分为多个岩性段,从混合花岗岩至浅粒岩与风化壳,垂向上可进行类似于沉积岩层序的地层对比,岩性在平面上也呈现分区性。变质岩体在岩性上是不均一的、非均质的块体。矿物种类和岩石类型对研究区变质岩裂缝型储层起重要作用,碎裂化变粒岩、浅粒岩、混合花岗岩与片麻岩可作为优质储层。     

The Response of Carbon Geochemistry to Hydrological Events within an Urban River,Southwestern China

Natural and anthropogenic impacts on dissolved inorganic carbon (DIC) within an urban river, Nanming River in southwestern China, were investigated using hydrochemistry and carbon isotopic compositions of dissolved inorganic carbon (δ¹³C_DIC). Because of the anthropogenic inputs, generally, the TDS values and major ionic compositions showed an increasing trend along the mainstream. The TDS values and most of the dissolved solutes compositions showed a dilution effect during storms, but the dilution effect did not strictly follow the theoretical dilution curve. Lighter δ¹³C_DIC values in the river after a rainstorm reflected the influx of rain water with biological CO₂ during the rain event. Meanwhile, the negative relationship between δ¹³C_DIC values and dissolved inorganic carbon concentrations in the mainstream at different sampling campaigns suggested significant degradation of organic matter in the riverine channels. The variabilities of DIC in an urban river were mainly impacted by biological activities and infiltration of soil carbon dioxide. This study demonstrated that hydrological events and anthropogenic inputs are the main controls on the variations of dissolved solutes compositions and the DIC dynamics for an urban river.     

An improved hardening-damage creep model of lean coal: a theoretical and experimental study

Creep is an important rheological behavior of coal, impacting pillar stability, gateway support performance, and construction costs in underground mining. It is of great significance to study the creep mechanism of coal to prevent creep failure. In this paper, uniaxial compressive creep tests of raw lean coal under multiple stages are conducted, the increasing instantaneous elastic modulus and decreasing viscosity coefficient are calculated to analyze the hardening-damage creep mechanism of coal, and some new conclusions are as follows. When the stress is low, the hardening effect exists, and coal strain shows an instantaneous response. At high stress, both the damage effect and hardening effect work and coal strain shows time-dependent transient creep and steady creep. During multistage creep, coal is first hardened, then weakened, and finally fails due to well-developed cracks. Based on the strain evolution laws of lean coal at different stress levels, an elastic viscous-plastic model is established, and the hardening function and damage function are introduced into the model to obtain an improved hardening-damage creep model. This model is used to fit the creep data, and the model curves match the testing data very well, showing much better accuracy than other models. This model is simple with clear physical meanings of the elements and can reflect the nonlinear hardening-damage creep of raw lean coal under uniaxial compression very well.     

http://www.sciencedirect.com/science/article/pii/S1674987111000600

Detailed studies on Late Devonian to Early Carboniferous carbonate rocks in central Hunan, southern China have led to the recognition of 25 lithofacies which can be grouped into:(1) inner ramp peritidal platform,(2) inner ramp organic bank and mound.(3) mid ramp,(4) outer ramp,and(5) shelf basin fades associations.The peritidal platform fades association dominates the Zimenqiao Formation (Namurian A or late Datangian) and is characterized by gypsum and dolostone-containing sequences, indicating a peritidal platform environment.The other four fades associations dominate the Menggongao Formation(late Famennian).Liujiatang Formation(Tournaisian or Yangruanian).Shidengzi Formations (early Visean or early Datangian).Five upward-shallowing cycles were distinguished in these three Formations.The predominant fades associations developed in each Formation demonstrate an overall transgression-regression cycle in the Late Devonian to Early Carboniferous in central Hunan.The overall transgressive sequence was preserved in the Shaodong.Menggongao.and Liujiatang Formations,and the overall regressive sequence was preserved in the Liujiatang.Shidengzi.Ceshui and Zimenqiao Formations.     

基于S变换和瞬时旅行时属性的自动初至拾取方法研究

地震波走时拾取是地震资料前期处理过程中的一个重要步骤,同时也是后期层析成像方法中计算速度的重要依据。本文提出了一种新的自动初至拾取的方法,利用地震信号的瞬时旅行时属性进行地震波自动初至拾取,瞬时旅行时属性的计算包括两个独立但相关联的部分,首先通过S变换将地震信号转换到时频域,然后利用映射算子将时频域表征映像回时间域得到瞬时旅行时,从而实现自动拾取初至。理论模型和实际地震资料处理的结果表明,该方法可以有效地拾取地震波初至时间。     

西沙群岛西科1井梅山组一段储层物性特征及储集评价

基于岩芯观察和薄片鉴定,对西沙群岛西科1井梅山组一段生物礁储层特征进行系统分析和评价。研究表明,岩石成分为方解石和白云石;岩石组构为骨架和碎屑颗粒、基质、胶结物;岩石类型有白云岩、灰质白云岩、颗粒灰岩、泥粒灰岩和漂砾灰岩。储集空间类型包括原生粒间孔、粒内孔和晶间孔,次生溶孔、铸模孔、粒内溶孔和裂缝。白云岩储层物性好,颗粒灰岩储层物性差。研究区主体为高孔、高渗型储层,其次为中孔、中渗型储层,含有少量的低孔、低渗型储层。     

油气管道顶管施工中顶力预测模型

顶力计算是顶管施工的重要内容,关系到整个工程的造价和成败。通过对顶力预测进行理论分析,针对混凝土顶管施工建立顶力计算模型,依次计算总顶力的两个组成部分：顶进正面阻力和管周摩擦阻力。采用朗金主动土压力理论计算水平土压力,砂性土采用“水土分算”方法而粘性土采用“水土合算”方法,进而计算顶进正面阻力;结合土柱压力理论和马斯顿压力理论,分别建立相应的管周土压力模型,给出管周总摩擦阻力的计算方法。得到适用条件明确、计算结果可靠的顶力计算公式,该公式的计算结果与工程实例相比较,满足工程要求。     

西藏东部地区矿产资源开发环境遥感监测成果

西藏东部地区矿产资源开发环境遥感监测项目圆满完成了2012—2014年度西藏东部地区矿山开发状况、矿山环境和矿产资源规划执行情况年度动态遥感监测,首次形成了完整覆盖西藏东部地区的矿产资源开发全要素数据集,并针对矿产资源规划执行情况、矿山典型地物三维体量分析、矿山开发强度综合评价与区划等相关专题开展了综合研究与评价工作。上述本底数据集和综合研究成果可为国土资源部、中国地质调查局和地方管理部门制定矿产资源开发、矿山地质环境管护等规划和政策提供决策依据。