Origin of scattered disk resonant TNOs: Evidence for an ancient excited Kuiper belt of 50 AU radius

Resonance occupation of trans-neptunian objects (TNOs) in the scattered disk (>48 AU) was investigated by integrating the orbits of 85 observed members for 4 Gyr. Twenty seven TNOs were locked in the 9:4, 16:7, 7:3, 12:5, 5:2, 8:3, 3:1, 4:1, 11:2, and 27:4 resonances. We then explored mechanisms for the origin of the resonant structure in the scattered disk, in particular the long-term 9:4, 5:2, and 8:3 resonant TNOs (median 4 Gyr), by performing large scale simulations involving Neptune scattering and planetary migration over an initially excited planetesimals disk (wide range of eccentricities and inclinations). To explain the formation of Gyr-resident populations in such distant resonances, our results suggest the existence of a primordial planetesimal disk of at least 45-50 AU radius that suffered a dynamical perturbation leading to 0.1-0.3 or greater eccentricities and a range of inclinations up to ∼20° during early stages of the Solar System history, before planetary migration.     

楚雄盆地上三叠统储集体成因类型及几何模式

楚雄盆地经历多期构造变形.晚三叠世,盆地北部由盆底扇深水环境过渡到沿岸砂坝和三角洲环境.该时期形成辫状河道砂、砾岩体、滨滩砂岩体,河口坝砂岩体和分流河道充填砂岩体四类储集体,构成三种相结合,即扇储集体、三角洲前缘储集体和三角洲平原储集体,几何形态对应为透镜状、带状和不规则状.     

A rapid method to map the crustal and lithospheric thickness using elevation, geoid anomaly and thermal analysis. Application to the Gibraltar Arc System, Atlas Mountains and adjacent zones

We present a method based on the combination of elevation and geoid anomaly data together with thermal field to map crustal and lithospheric thickness. The main assumptions are local isostasy and a four-layered model composed of crust, lithospheric mantle, sea water and the asthenosphere. We consider a linear density gradient for the crust and a temperature dependent density for the lithospheric mantle. We perform sensitivity tests to evaluate the effect of the variation of the model parameters and the influence of RMS error of elevation and geoid anomaly databases. The application of this method to the Gibraltar Arc System, Atlas Mountains and adjacent zones reveals the presence of a lithospheric thinning zone, SW–NE oriented. This zone affects the High and Middle Atlas and extends from the Canary Islands to the eastern Alboran Basin and is probably linked with a similarly trending zone of thick lithosphere constituting the western Betics, eastern Rif, Rharb Basin, and Gulf of Cadiz. A number of different, even mutually opposite, geodynamic models have been proposed to explain the origin and evolution of the study area. Our results suggest that a plausible slab-retreating model should incorporate tear and asymmetric roll-back of the subducting slab to fit the present-day observed lithosphere geometry. In this context, the lithospheric thinning would be caused by lateral asthenospheric flow. An alternative mechanism responsible for lithospheric thinning is the presence of a hot magmatic reservoir derived from a deep ancient plume centred in the Canary Island, and extending as far as Central Europe.     

阜东斜坡-北三台地区成藏动力学系统研究

成藏动力学系统是在含油气系统理论的基础上,针对油气流体矿产的特点而提出来的.含油气盆地实质上不仅是一个"低温热化学反应器",更是一个复杂的流体(油气水)渗流的成藏动力系统.油气从源岩到圈闭的作用机制和过程非常复杂,通过探讨油气成藏各个环节,指出影响油气赋存的因素,可以指导油气勘探工作.基于成藏动力学系统理论,将阜东斜坡-北三台地区划分为8个成藏动力学系统,建立了6个成藏动力学模式,提出2个勘探导向目标:①在勘探程度较低的白垩系寻找它源多向充足的油气藏类型;②在斜坡区寻找以三叠系小泉沟群为源岩所形成的自源封闭型高压油气藏.     

Mapping East African tropical forests and woodlands — A comparison of classifiers

In mapping the forest–woodland–savannah mosaic of Budongo Forest Reserve, Uganda, four classification methods were compared, i.e. Maximum Likelihood classifier (MLC), Spectral Angle Mapper (SAM), Maximum Likelihood combined with an Expert System (MaxExpert) and Spectral Angle Mapper combined with an Expert System (SAMExpert). The combination of conventional classifiers with an Expert System proved to be an effective approach for forest mapping. This was also the first time that the SAMExpert had been used in the mapping of tropical forests. SAMExpert not only maps with high accuracy, but is also fast and easy to use, making it attractive for use in less developed countries. Another advantage is that it can be executed on a standard PC set up for image processing.Combining the conventional classifiers (MLC and SAM) with the Expert System significantly improved the classification accuracy. The highest overall accuracy (94.6%) was obtained with SAMExpert. The MaxExpert approach yielded a map with an accuracy of 85.2%, which was also significantly higher than that obtained using the conventional MLC approach.The SAMExpert classifier accurately mapped individual classes. Of the four classes of woodland mapped, the Open Woodland (with Terminalia) and Wooded Grassland classes were more accurately mapped using SAMExpert. The Open Woodland had been previously identified by ecologists, but had never been mapped.     

江苏省国土资源省-市-县三级公文协同办理系统结构设计研究

本文通过对江苏省国土资源电子政务建设思路的阐述,对全省各级国土资源部门信息化现状差异的分析,设计了全省三级公文协同办理系统的框架,并逐层深入设计了三大核心软件系统的结构,最后结合全省应用实例,介绍了本系统结构的应用情况。     

北京市突发性地质灾害预警预报信息系统设计研究

本文以北京市突发性地质灾害预警预报信息系统为研究对象,讨论了系统设计原则,研究和设计系统的总体架构和详细架构,提出了功能模块、数据库,对比分析了预警预报模型与GIS集成的几种方式。     

VirtuoZo全数字摄影测量系统制作DEM的实用方案

介绍利用VirtuoZo全数字摄影测量系统制作DEM的工作流程,说明生成DEM的具体操作步骤,指出提高作业精度的具体措施和办法.     

基于GIS的通信资源信息管理平台

GIS与管理信息系统相结合是大型企业和部门开发信息系统软件,提高信息化程度的很好思路。本文介绍了某部基于GIS的通信资源信息管理平台软件的设计思路,主要功能实现方式,应用情况,并对存在不足提出了改进的设计。