桩基完整性检测与面向对象编程     

艾东海  邓中华  仲伟亚  周曾辉 《岩土力学》2003,(Z2)

根据反射波法原理,探讨应力波在一维变截面和不同周土中的传播及反射,从数值分析的角度推导相应的计算公式,并利用面向对象编程实现该计算方法。  相似文献   

地质公园的建设与发展   总被引：25，自引：0，他引：25  

李晓琴  赵旭阳  覃建雄 《地理与地理信息科学》2003,19(5):96-99

迄今为止，我国已建立国家地质公园44处，但地质公园建设与发展的理论体系还相当不健全。笔者就地质公园建设与发展中的地质公园选址、地质公园范围的界定和地质公园规划三个重要问题进行了初步探讨。这对国家地质公园建设与发展具有一定参考、借鉴或指导意义。  相似文献   

The Grouping of the Strike-Slip Offset Data and Its Relation With the Seismicity Along Middle Segment of the Xiaojiang Active Fault     

Shen Jun  Wang Yipeng  Song Fangmin  Yu Weixian  Cao Zhongquan  Shen Xuhui  Hou Xueying  and Li ZhixiangInstitute of Geology  SSB  Beijing  ChinaInstitute of Earthquake Engineering  Seismological Bureau of Yunnan Province  Kunming  China 《中国地震研究》1998,(2)

The data of the strike-slip offset along the Xiaojiang active fault can be obviously grouped.The groups of small orders of magnitude data within 100 m show clear linear characteristics of increments between 8 m and 12 m,which indicates that the segments of the Xiaojiang active fault is of characteristic seismicity and the distribution of the values of each group indicates that there are smaller earthquakes and creep between two large earthquakes along each segment of the Xiaojiang active fault.The interval between two characteristic large earthquakes can be calculated with the increments for two groups of slip data and the slip rate of the fault.Furthermore,the frequency of smaller earthquakes can also be estimated by comparing the distributions of the displacements of the large earthquakes with the distributions of the values of each group of data.The groups of large slip displacements show that there is close relationship between the records of the displacements of the fault and the changes of the cli  相似文献   

线性和非线性横波型不稳定的数值研究   总被引：8，自引：0，他引：8  

张颖  张铭 《气象学报》1998,56(4):447-457

本文应用一个准二维的非线性非静力数值模式研究了线性和非线性横波型不稳定的中尺度模态的发展、演变和结构特征。结果表明：Ｒｉｃｈａｒｄｓｏｎ数对横波型不稳定的发展和演变有影响。Ｒｉ数越小,不稳定增长越快,且增长率最大的波的波长就越短。非线性横波型不稳定在其发展初期,可以用线性理论作很好的近似;随着不稳定的进一步发展,扰动增强,非线性作用增强,其扰动结构与线性情况相比发生了很大变化,扰动结构最后演变成以顺时针环流为主的结构。  相似文献   

球状模型的最优参数估计   总被引：9，自引：0，他引：9  

柏森  李小敏 《物探化探计算技术》1998,20(1):25-29

在地质统计学中,变差函数理论模型的拟合一直没有满意的算法。本文结合加权回归多项式法和线性规划法的优点,提出用目标规划法进行球状模型的参数估计,为地质统计学计算全过程自动化提供了重要的方法。  相似文献   

新疆河谷阶地的年代   总被引：10，自引：2，他引：8  

柏美祥 《内陆地震》1998,12(1):13-19

对新疆阿尔泰山,西准噶尔山地,天山南北及昆仑山２６条河流河谷阶地的年代学研究表明：高河漫滩主要形成于晚全新世时期３０００ａＢ．Ｐ．;Ｉ级阶地形成于中全新世时期６０００ａＢ．Ｐ．;Ⅱ和Ⅲ级形成于晚更新晚期１３０００～３４０００ａＢ．Ｐ;Ⅳ级以上阶地形成于晚更新世早期６７０００～９５０００ａＢ．Ｐ．。这些地貌面的年代是第四纪重要地质事件出现的时期。阶地高出河床的高度（Ｈ）与其相应的形成年代（Ａ）有较好  相似文献   

Stochastic differential dynamic programming for multi-reservoir system control     

F. A. El-Awar  J. W. Labadie  T. B. M. J. Ouarda 《Stochastic Environmental Research and Risk Assessment (SERRA)》1998,12(4):247-266

: As with all dynamic programming formulations, differential dynamic programming (DDP) successfully exploits the sequential decision structure of multi-reservoir optimization problems, overcomes difficulties with the nonconvexity of energy production functions for hydropower systems, and provides optimal feedback release policies. DDP is particularly well suited to optimizing large-scale multi-reservoir systems due to its relative insensitivity to state-space dimensionality. This advantage of DDP encourages expansion of the state vector to include additional multi-lag hydrologic information and/or future inflow forecasts in developing optimal reservoir release policies. Unfortunately, attempts at extending DDP to the stochastic case have not been entirely successful. A modified stochastic DDP algorithm is presented which overcomes difficulties in previous formulations. Application of the algorithm to a four-reservoir hydropower system demonstrates its capabilities as an efficient approach to solving stochastic multi-reservoir optimization problems. The algorithm is also applied to a single reservoir problem with inclusion of multi-lag hydrologic information in the state vector. Results provide evidence of significant benefits in direct inclusion of expanded hydrologic state information in optimal feedback release policies.  相似文献   

枣庄地下水与水资源可持续开发利用规划研究   总被引：1，自引：0，他引：1  

吴爱民  费瑾  邵景力  崔亚莉  文唐章 《地球学报》1998,19(4):371-376

缺水制约着中国北方及东部沿海城市的经济发展。本项研究探讨以能源原材料工业为主的粗放型工业地区的水资源可持续开发利用规划问题。在对枣庄市水资源条件研究与供需平衡分析基础上,充分考虑水资源的自然属性,生活资料属性,商品属性和环境因子功能,用多目标线性规划方法进行了水资源开发规划,提出了水资源可持续开发利用的管理建议,以期达到水资源开发利用与社会,经济,环境的协调发展。  相似文献   

基于地理信息可视化的线状符号表达方法的研究     

郑春燕  胡华科 《现代测绘》2004,27(1):44-46

本文根据线状要素地理信息表达的需要，对线状符号进行了分类．在分析了线状符号的视觉变量之后，给出了其图案单元的数据结构。最后结合线状符号的分解、组合特性提出了线状符号的配置方法。  相似文献   

Elongation and migration of sand dunes   总被引：3，自引：0，他引：3  

Haim Tsoar  Dan G. Blumberg  Yoav Stoler 《Geomorphology》2004,57(3-4):293-302

Two distinct processes are known to act on dynamic dunes, the process of migration by erosion on the windward side and deposition on the lee side, typical for transverse dunes, and the process of elongation typical for linear dunes. These two processes are determined by wind direction relative to the dune alignment. This article reviews the assertion that linear dunes experience lateral displacement in addition to elongation. Fieldwork on vegetated linear dunes (VLDs) and GIS work on seif dunes indicates no lateral migration for these dunes. Linear dunes can shift laterally only when a slip face, formed on the lee side, reaches the plinth of the dune. The winds from both sides of the seif dune are never symmetric; usually winds from one direction are more dominant and effective. The outcome is the formation of peaks and saddles along the dune. The strongest winds create a slip face on the lee side of the peak segments of the dune, oblique to the dune alignment, which reaches the base of the dune and displaces the peak downwind along the dune alignment. The internal structure of the seif dune is formed mostly by this dominant wind direction and gives the impression that the dune has shifted laterally. On the other hand, there are cases in which the wind directions relative to dune alignment fall between those of transverse and seif dunes. In such cases, both processes act on the dune, which subsequently experiences migration as well as elongation.  相似文献