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51.
网络经济已成为新的社会生产力的代表。广西地质矿产勘查开发局应该利用其行业和地域方面的固有优势,积极参与网络经济,以期打开矿业市场。文章提出了建立矿业网站的设想和框架。  相似文献   
52.
首先分析了地理信息系统的组成、地理信息系统数据的特征、地理信息系统数据库的功能,然后进行了中心式导航系统数据库的设计,给出了数据库模型的E-R图,最后描述了空间地理信息的查询功能。  相似文献   
53.
LINUX,一个优秀的代码开放的操作系统。对其内核代码的分析,无论对编程或者学习操作系统原理都将事半功倍。然而处于安全性考虑,CPU的设计者将系统空间和用户空间分离,这个措施造成了对内核代码进行调试运行的困难。有许多方法可以使用户程序进入系统空间,比如中断方式、系统调用方式……我们介绍的是采用模块的方式使应用程序进入系统空间。  相似文献   
54.
The computation of translunar Halo orbits of the real Earth–Moon system (REMS) has been an open problem for a long time, but now, it is possible to compute Halo orbits of the REMS in a systematic way. In this paper, we describe the method used for the numerical computation of Halo orbits for a time span longer than 41 years. Halo orbits of the REMS are computed from quasi-periodic Halo orbits of the quasi-bicircular problem (QBCP). The QBCP is a model for the dynamics of a spacecraft in the Earth–Moon–Sun system. It is a Hamiltonian system with three degrees of freedom and depending periodically on time. In this model, Earth, Moon and Sun are moving in a self-consistent motion close to bicircular. The computed Halo orbits of the REMS are compared with the family of Halo orbits of the QBCP. The results show that the QBCP is a good model to understand the main features of the Halo family of the REMS.  相似文献   
55.
长江三峡工程地壳形变监测网络   总被引:19,自引:10,他引:9  
长江三峡工程地壳形变监测网络,采用了当今高精度GPS、INSAR空间大地测量技术,并与精密水准测量,精密重力测量,精密激光测距和峒体连续形变监测等技术相结合,构成一个空间上点、线、面结合,时间上长、中、短兼顾的高精度,高时空分辨率的地壳形变监测网络。该网络既可获取三峡库区特别是库首区区域形变场和区域应变场的动态变化,监测库区主要断层活动,为水库诱发地震预测及研究服务,又可用于气象、滑坡地质灾害监测等,该监测网络于1997年底开始建设,2001年6月建成,到目前为止,已获得大量宝贵的观测资料,必将产生显著的经济效益和社会效益。  相似文献   
56.
利用 2 0 2个太阳附近疏散星团的视向速度和自行观测资料 ,对太阳的运动和银河系的运动学参数进行了研究。其中 ,距离在 0 .5kpc到 2kpc之间的 12 8个疏散星团对平均太阳运动分量的解算结果是 (u0 ,v0 ,w0 ) =(- 13.8± 1.4 ,- 5 .0± 1.6 ,- 11.6± 2 .9)km/s ;Oort常数和银河系径向运动参数的解算结果分别为 (A ,B) =(16 .9± 1.1,- 11.6± 2 .6 )km·s- 1·kpc- 1及 (C ,D) =(2 .5± 1.1,- 2 .1± 0 .9)km·s- 1·kpc- 1。  相似文献   
57.
介绍了一种新颖的静态传感器网络实现方法,它利用可移动的中继节点来收集静态传感器网络的数据,有效的节约各传感器节点的能源,延长整个传感器网络的有效工作时间。也可以对该方法进行适当的改进,应用到某些实时性要求较高的场合中去。然后介绍了应用该原理实现的一个通讯协议。  相似文献   
58.
Morphological analysis of the drainage system in the Eastern Alps   总被引:2,自引:1,他引:1  
We study the morphology of the major rivers draining the Eastern Alps to test whether the active tectonics of this part of the orogen is reflected in the shape of channel profiles of the river network. In our approach we compare channel profiles measured from digital elevation models with numerically modelled channel profiles using a stream power approach. It is shown that regions of high stream power coincide largely with regions of highest topography and largest uplift rates, while the forelands and the Pannonian Basin are characterised by a significantly lower stream power. From stream power modelling we conclude that there is young uplift at the very east of the Eastern Alps, in the Bohemian Massif and in the Pohorje Range. The impact of the Pleistocene glaciations is explored by comparing properties of rivers that drain in proximal and distal positions relative to the ice sheet during the last glacial maximum. Our analysis shows that most knick points, wind gaps and other non-equilibrium features of catchments covered by ice during the last glaciations (Salzach, Enns) can be correlated with glacial processes. In contrast the ice free catchments of the Mur and Drava are characterized by channels in morphological equilibrium at the first approximation and are showing only weak evidence of the strong tectonic activity within these catchments. Finally, the channel profiles of the Adige and the divide between the upper Rhine and Danube catchments differ significantly from the other catchments. We relate this to the fact that the Adige and the Rhine respond to different base levels from the remainder of the Eastern Alps: The Adige may preserve a record from the Messininan base level change and the Rhine is subject to the base level lowering in the Rhine Graben.  相似文献   
59.
Based on our detailed structural characterization, we examine possible relationships between thrust faults and strike-slip faults and thrust-cored folds and depositional units in the Silla Syncline, a 4 km wide fold composed of fine-grained mudstone, coarse sandstone and conglomerate deposits of the Cerro Toro Formation in the Magallanes foreland basin, Chilean Patagonia. The syncline is bounded on its western flank by an asymmetric anticline and on its eastern flank by a broad zone of thrust faults and associated folds, which are oriented sub-parallel to the syncline axis. Deposition of the coarse-grained units of the Silla Syncline appears to have taken place in this structurally defined trough controlled primarily by thrust fault related growth structures flanking the syncline.The syncline and surrounding area have also been deformed by two sets of strike-slip faults, one right-lateral and one left-lateral. The strike-slip and thrust faulting operated contemporaneously for much of their active periods, although it appears that thrust faulting, confined within the fine-grained units, initiated slightly earlier than strike-slip faulting. In addition, younger igneous intrusions at high angle to bedding generally localize along the strike-slip faults. The cross-cutting relationships among the intrusions, strike-slip faults, and flexural slip faults show that all these structures were active during the same period, which extends beyond mid-Miocene.These conclusions support the premise that structures in deep-water sediments are important for understanding not only the deformation of a foreland basin, but also its depositional architecture.  相似文献   
60.
Singh et al (2005) examined the potential of the ANN and neuro-fuzzy systems application for the prediction of dynamic constant of rockmass. However, the model proposed by them has some drawbacks according to fuzzy logic principles. This discussion will focus on the main fuzzy logic principles which authors and potential readers should take into consideration.  相似文献   
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