Causal models as multiple working hypotheses about environmental processes

The environmental modeller faces a dilemma. Science often demands that more and more process representations are incorporated into models (particularly to avoid the possibility of making missing process errors in predicting future response). Testing the causal representations in environmental models (as multiple working hypotheses about the functioning of environmental systems) then depends on specifying boundary conditions and model parameters adequately. This will always be difficult in applications to a real system because of the heterogeneities, non-stationarities, complexities and epistemic uncertainties inherent in environmental prediction. Thus, it can be difficult to define the information content of a data set used in model evaluation and any consequent measures of belief or verisimilitude. A limit of acceptability approach to model evaluation is suggested as a way of testing models, implying that thought is required to define critical experiments that will allow models as hypotheses to be adequately differentiated.     

珠江口盆地深水区白云凹陷气烟囱特征及成藏模式

以高分辨率三维地震资料为基础,结合地震属性,在珠江口盆地深水区白云凹陷识别出了大量的气烟囱现象。气烟囱可分为根部、过路区和顶部三个组成单元,各个单元具有不同的地震异常特征,主要通过同相轴的侧向变化,振幅、频率、连续性的局部增强和减弱,AVO响应以及它们的组合来识别。气烟囱根部是气体释压的初始部位,是气源供应区;过路区是流体泄压所经过的区带,在整个气烟囱结构的空间中占有主体地位;顶部常形成气藏。对白云凹陷建立了气烟囱顶部聚集和侧翼聚集两种气藏成藏模式,它们均由古近系文昌组—恩平组的河湖相沉积提供烃源。     

云南普洱李新田铅锌矿成矿模式

矿床受大型逆冲推覆构造带控制,具有良好的成矿条件和地质构造背景,矿区找矿潜力很好,值得进一步工作。     

陕西商南金丝峡地质公园岩溶峡谷演化模式研究

陕西商南金丝峡国家地质公园成立于2009年8月,以岩溶峡谷、多层岩溶溶洞及十三级瀑布群地质遗迹为特色,包括白龙峡景区、黑龙峡景区、青龙峡景区、石燕寨景区及丹江源景区五大景区,是我国著名的岩溶峡谷型地质公园。岩溶峡谷地质遗迹具有多样性,在空间上总体有隘谷-嶂谷-峡谷(狭义)展布的规律。公园位于南秦岭构造带,岩石主要由白云岩、白云质灰岩、石灰岩组成,该岩溶峡谷景观系统的形成在秦岭具有典型性,与公园岩石地层、断裂构造、崩塌作用、新构造运动及溶蚀性径流侵蚀等因素密切相关,其形成机理具有自身的独特性,称之为"金丝峡模式",即岩溶峡谷谷坡崩塌式后退、平面上呈鱼鳞状扩展的峡谷演化模式。     

叶片辐射传输模型PROSPECT 理论研究

综述植物叶片辐射传输PROSPECT 模型的理论,并对其理论来源PLATE 模型作了扼要介绍。进一步研究叶片结构、叶片光学吸收参数和叶片反射率、透射率之间的非线性关系,给出如何用单层致密叶片迭代来表示多层非致密叶片的反射率、透射率。讨论了Stokes 光学系统理论及其在模型理论中的应用,并用复向量的方法证明其各向同性光学介质中反射率和透射率递推关系式。表明PROSPECT 模型基于良好的物理模型,在满足假设条件下,能够准确模拟叶片的反射率和透射率。     

湖南雪峰山地区干酪根的拉曼光谱研究

干酪根是沉积有机质的主体,是石油地质工作研究的重要对象,目前利用激光拉曼光谱进行干酪根的研究较少.雪峰山地区干酪根的拉曼光谱测试结果表明:干酪根的一级拉曼光谱峰位差与镜质体反射率之间有着系统的规律性变化,在Ro＜ 2.4％时,峰位差随Ro的增大迅速增大,其相关系数为0.82;Ro在2.4％～2.9％之间时,二者关系不明显,离散度较大;Ro＞2.9％时,峰位差随Ro的增大逐渐减小,相关系数为0.88.镜质体反射率是衡量有机质成熟度和热演化程度的重要指标,干酪根的拉曼光谱特征与镜质体反射率之间的关系表明激光拉曼光谱法可以成为有机质成熟度和热演化程度研究的新方法.     

Petrogenesis of some palaeozoic rhyolites in Victoria

Thick rhyolite sheets occur within the middle Palaeozoic cauldron subsidence complexes in Victoria. Well‐preserved eutaxitic and vitroclastic textures in the basal regions of the Rubicon, Jemba, and Ryans Creek rhyolites provide evidence of an ash‐flow origin. Subsequent recrystallization during cooling has masked these primary textures towards the central and upper parts of the rhyolitic sheets. All three rhyolites show dense welding throughout and the major zonation observed is in the degree of granophyric recrystallization.

Despite the turbulent ash‐flow emplacement and the possibility of post‐eruptive chemical modification, the mineralogical and chemical trends within vertical sequences in the Rubicon and Jemba Rhyolites are essentially continuous and represent the inverted variation within the original magma body. The bulk compositions of the rhyolites suggest that conditions of water saturation were closely approached or attained within the magma chamber. The chemical variation with increasing height and phenocryst content in the rhyolites can be summarized as: increasing K, Ca, Ba and Sr, and decreasing Na and Rb. Whereas this variation is in accord with frac‐tionation theories, it is more likely to have resulted from the partial fusion process believed to have been responsible for the generation of the acid magmas.     

多源SAR影像区域网平差的比较研究

本文将有理函数模型(RFM)引入多源SAR遥感影像区域网平差中,并采用多种地面控制点布设方案,对基于严格几何处理模型和带像方仿射变换补偿的RFM区域网平差精度进行了对比分析.试验表明,对于多源SAR影像,在地面控制点较多且分布良好的情况下,基于严格几何处理模型的区域网平差可以获得较好的目标定位结果;基于RFM的区域网平差可以获得与基于严格几何处理模型的区域网平差几乎相当的目标定位精度,且受地面控制点分布和数量影响较小,非常适合稀疏地面控制点情况下的SAR遥感影像几何定位.     

改进SFS的月面撞击坑三维恢复算法研究

为了实现探月二期中单幅影像条件下的月面撞击坑三维地形恢复,文章基于Lommel-Seeliger反射模型,提出了正则化约束的明暗恢复形状(SFS)三维恢复算法,以特征边缘线点的梯度比例作为起算,演化得到撞击坑内部所有点的梯度比例,实现了反射方程的正则化.采用实际月面撞击坑影像和模拟影像验证分析,结果证明本文提出的算法优于Tsai算法,能够有效地实现月面撞击坑地形的三维恢复.