金门供水仿真分析          下载免费PDF全文

颜志俊  罗恭和 《水科学进展》1997,8(3):292-295

针对金门用水现状、发展规划和大陆水资源及工程供水条件,建立大陆向金门供水的水资源系统仿真模型,应用聚合-分解-协调的求解技术,模拟分析不同工程措施供水方案下的金门供需状况,为决策部门提供决策的技术依据。  相似文献   

大冲击功液动锤的研究及其应用          下载免费PDF全文

殷琨  菅志军  蒋荣庆 《探矿工程》1996,(4):8-10

从液动锤基础理论出发，依据理论计算公，科学建立数学模型，开发计算机软件，对液动锤内部动力过程及工作参数进行计算机模拟仿真电算，寻求大幅度提高冲击功的途径和方法。  相似文献   

层析成像中的波形反演   总被引：1，自引：0，他引：1  

王大川  严忠琼 《物探化探计算技术》1996,18(4):298-303

在波动方程有限差分数值模拟基础上，用波形记录残差平方并建立目标函数。对目标函数进行梯度优化，我们得出了介质速度的迭代公式。通过计算目标函数梯度我们可以对介质进行速度校正，从而获得反演解。经数值试验证明这是一种很有效的反演方法。  相似文献   

用快速仿真退火进行走时层析成像     

Velis  DR 郭爱缨 《物探化探译丛》1996,(A00):66-68

本文主要介绍一种与射线追踪无关的走时成像方法，使用一种非线性最优化算法，称为非常快速的仿真退火。利用立方Ｂ样条对地下地质体进行参数化，此网格在水平和垂直坐标是可变化的，这个灵活的网格可以容 等复杂程度的构造，并只用几个节点，我们试图求观测与预测走时之间的均言差进行极小化。时使用有限差分算法，不仅在样条节点位置上求速度，而且还求在每个维方向上的网格间距，由于在计算期间避免了局部极小，求出的解与初始模  相似文献   

电法勘探的发展和展望   总被引：9，自引：1，他引：9       下载免费PDF全文

何继善 《地球物理学报》1997,40(Z1):308-316

电法勘探在经历了近一个世纪的发展后，其方法理论、仪器设备、野外数据采集、处理和解释等方面都经历了一系列重大变化．本文以方法理论的进展为主线，回顾、展望了目前电法勘探中几个重要而令人关注的研究焦点．这些问题的研究进展将会对21世纪的电法勘探产生深远的影响．  相似文献   

数字地震记录与模拟地震记录波形的一致性对比分析     

王平  狄秀玲 《地震地磁观测与研究》2004,(Z1)

通过对模拟台网与数字台网记录到的地震震相和波形进行了对比分析,从比较情况看,两套系统地震记录的波形特征较为一致。  相似文献   

A Modeling Study of the Effects of Anomalous Snow Cover over the Tibetan Plateau upon the South Asian Summer Monsoon   总被引：1，自引：0，他引：1  

刘华强  孙照渤王举 闵锦忠 《大气科学进展》2004,21(6):964-975

The effect of anomalous snow cover over the Tibetan Plateau upon the South Asian summer monsoon is investigated by numerical simulations using the NCAR regional climate model (RegCM2) into which gravity wave drag has been introduced. The simulations adopt relatively realistic snow mass forcings based on Scanning Multi-channel Microwave Radiometer (SNINIR) pentad snow depth data. The physical mechanism and spatial structure of the sensitivity of the South Asian early summer monsoon to snow cover anomaly over the Tibetan Plateau are revealed. The main results are summarized as follows. The heavier than normal snow cover over the Plateau can obviously reduce the shortwave radiation absorbed by surface through the albedo effect, which is compensated by weaker upward sensible heat flux associated with colder surface temperature, whereas the effects of snow melting and evaporation are relatively smaller.The anomalies of surface heat fluxes can last until June and become unobvious in July. The decrease of the Plateau surface temperature caused by heavier snow cover reaches its maximum value from late April to early May. The atmospheric cooling in the mid-upper troposphere over the Plateau and its surrounding areas is most obvious in May and can keep a fairly strong intensity in June. In contrast, there is warming to the south of the Plateau in the mid-lower troposphere from April to June with a maximum value in May.The heavier snow cover over the Plateau can reduce the intensity of the South Asian summer monsoon and rainfall to some extent, but this influence is only obvious in early summer and almost disappears in later stages.  相似文献   

地形可视化的进展与评述   总被引：4，自引：0，他引：4  

詹发新 《四川测绘》2004,27(2):58-61

地形可视化由于具有越来越广泛的用途，因此越来越多地引起了大家的关注。本文在简要论述科学可视化、地形可视化定义及其研究内容的基础上，着重讨论了当前地形可视化的表达手段、可视化建模与技术、可视化生成工具、实时地形生成等方面的研究现状及存在的问题，最后对可视化的应用前景和发展趋势进行了展望。  相似文献   

地球内核最上部100km的区域变化     

A．Stroujkova  V．F．Cormier  申彤 《世界地震译丛》2005,(3):42-49

利用距离为118°-140°的PKIKP和PKiKP波形检验了地球内核最上部 100 km的结构。在赤道地带发现的内核最上部低速层的证据主要位于西经20°至东经 140°。在纬度方向,从南纬35°印度洋下面至北纬60°亚洲的下面可以监测到这一异常。用波形模拟方法可以推断该低速层的最大厚度为40 km,此时波速突变约3％。我们认为,该层可能为新近固结的地核区域,在该区域同时存在活跃的外核成分对流和内核新晶体增长。  相似文献   

Biomineralization of Uranium: A Simulated Experiment and Its Significance   总被引：5，自引：0，他引：5  

L. L. BARTON  H. WIATROWSKI 《《地质学报》英文版》2005,79(1):134-138

A simulated experimental reduction of U^v1 and the synthesis of uraninite by a sulfate-reducing bacteria,Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were:35℃, pH=7.0-7.4, corresponding to the environments of formation of the sandstone-hosted interlayer oxidation-zone type uranium deposits in Xinjiang, NW China. Uraninite was formed on the surface of the host bacteria after a one-week‘s incubation. Therefore, sulfate-reducing bacteria, which existed extensively in Jurassic sandstone-producing environments,might have participated in the biomineralization of this uranium deposit. There is an important difference in the orderdisorder of the crystalline structure between the uraninite produced by Desulfovibrio desulfuricans and naturally occurring uraninite. Long time and slow precipitation and growth of uraninite in the geological environment might have resulted in larger uraninite crystals, with uraninite nanocrystals arranged in order, whereas the experimentally produced uraninite is composed of unordered uraninite nanocrystals which, in contrast, result from the short time span of formation and rapid precipitation and growth of uraninite. The discovery has important implications for understanding genetic significance in mineralogy, and also indicates that in-situ bioremediation of U-contaminated environments and use of biotechnology in the treatment of radioactive liquid waste is being contemplated.  相似文献