非共振二阶椭圆型方程解的存在唯一性

利用Galerkin逼近方法和minimax原理，证明了非线性非共振椭圆型方程弱解的存在唯一性。     

2006年台湾屏东7.0级地震救灾与应变分析

2006年12月26日20时26分和20时34分,台湾屏东县相继发生两次芮氏规模7.0地震①.地震发生后,屏东县立即成立了"12.26震灾"灾害应变中心,积极开展灾害防救工作.通过此次地震的抢救过程,检讨分析应变中心应变机制之优缺点,希望今后能为相关单位进行莺大灾害抢救时提供参考,并得到更准确、适用、有效的抢救作业程序.     

中国粮食生产效率空间溢出网络及提升路径

现有研究普遍关注粮食生产单元自身资源禀赋以及功能属性,对于经济主体相互作用所产生的外部性研究十分有限。为此,本文在空间引力模型的基础上着重分析网络外部性对粮食生产效率的影响,并以此为逻辑起点进一步探讨网络提升路径以及各空间单元在整体网络中的综合定位与潜力。结果表明,中国粮食生产网络空间溢出效应显著,对粮食生产效率具有明显的促进作用,其实质是规模经营思想在空间维度的扩展,符合近带动远辐射规律,且交通基础设施的互通互联与人口流动是实现网络空间外溢的主要路径。同时,整体网络中共存在4种潜在节点,包括核心控制型、局域核心型、潜力型以及边缘型。未来应充分发挥核心控制型节点的辐射带动作用,加强东西轴带的空间交互影响,实现农业资源技术的跨地域流动与互补。     

影像中国服务器性能优化

三维环境下影像发布,由于数据量大,网络瓶颈等问题导致响应速度不够理想,客户端体验较差。本文采用数据库链接池技术、存储过程、多线程技术等大大优化了影像中国服务器性能,增强了其稳定性,基本满足用户并发的要求。     

大型地下工程岩溶涌(突)水模式的水文地质分析及其工程应用

大型地下工程中涌(突)水成灾的大部分属于岩溶涌(突)水.岩溶含水介质类型、岩溶蓄水构造与地下工程岩溶涌(突)水形式密切相关.本文首先将岩溶含水介质划分为快速紊流和缓慢渗流两大系统,分析了典型的岩溶蓄水构造及其对地下工程施工运营的影响,然后给出了大型地下工程中岩溶涌(突)水的典型模式,最后对岩溶区大型地下工程防水工作的程式进行了探讨.     

Stability of earth dam contaminated by chemical transport

When chemicals are introduced into the oil, they affect soil properties such as hydraulic conductivity and stress–strain behavior. In this study, several chloride concentrations are varied from 0 to 20 per cent to analyse the effect of chemicals on soil properties. A series of laboratory triaxial tests are performed on the cylindrical specimens of sand–bentonite mixture with different sodium chloride contents (5, 10, 15 per cent) by Nannapaneni. Deformation (elastic modulus, E) and strength (cohesion, c′, and angle of friction, ϕ′) parameters are obtained from the triaxial tests as functions of confining pressure and sodium chloride concentrations, and variations of parameters are incorporated into stability analysis. The stress–strain–strength behaviour based on the above strength parameters is introduced in a finite element procedure with a modified residual flow procedure (RFP). By integrating a slope stability procedure in the finite element method, the stability with time of earth dam contaminated by sodium chloride is examined. It is found that increasing sodium chloride concentration for the soil considered increases stability. However, the procedure is general and can allow stability analysis under the influence of other chemical which may lead to decrease in stability. Copyright © 1999 John Wiley & Sons, Ltd.     

洪浩尔舒特凹陷油气藏形成条件与勘探实践

洪浩尔舒特是近年来二连新区勘探高速度、快节奏取得重要突破的一个凹陷。研究表明 ,该凹陷具有阿尔善组、腾一段两套有效烃源岩 ,阿尔善组、腾一段是主要储油层系 ,腾二段是重要含油层系 ,斜坡带上的鼻状构造、洼中的反转背斜、陡带断鼻是油气聚集的主要场所。储油岩主要为扇三角洲、水下扇沉积的岩屑砂岩、含砾砂岩 ,富含火山碎屑成分 ,凝灰质、高岭石粘土含量高 ,储层物性差 ,油层易受污染 ,油层保护是获得油气勘探突破的重要保障 ,压裂改造是获得较高产量的重要手段     

Finite locally resonant Metafoundations for the seismic protection of fuel storage tanks

This paper introduces a novel seismic isolation system based on metamaterial concepts for the reduction of ground motion-induced vibrations in fuel storage tanks. In recent years, the advance of seismic metamaterials has led to various new concepts for the attenuation of seismic waves. Of particular interest for the present work is the concept of locally resonant materials, which are able to attenuate seismic waves at wavelengths much greater than the dimensions of their unit cells. Based on this concept, we propose a finite locally resonant Metafoundation, the so-called Metafoundation, which is able to shield fuel storage tanks from earthquakes. To crystallize the ideas, the Metafoundation is designed according to the Italian standards with conservatism and optimized under the consideration of its interaction with both superstructure and ground. To accomplish this, we developed two optimization procedures that are able to compute the response of the coupled foundation-tank system subjected to site-specific ground motion spectra. They are carried out in the frequency domain, and both the optimal damping and the frequency parameters of the Metafoundation-embedded resonators are evaluated. As case studies for the superstructure, we consider one slender and one broad tank characterized by different geometries and eigenproperties. Furthermore, the expected site-specific ground motion is taken into account with filtered Gaussian white noise processes modeled with a modified Kanai-Tajimi filter. Both the effectiveness of the optimization procedures and the resulting systems are evaluated through time history analyses with two sets of natural accelerograms corresponding to operating basis and safe shutdown earthquakes, respectively.     

Design of friction damped structures using lateral force procedure

A trilinear model is used to simulate the seismic resisting mechanism of a single‐degree‐of‐freedom friction‐damped system to reflect the situation in which both dampers and frame members lose their elastic resistance. The seismic response of the friction‐damped system is normalized with respect to the response of its corresponding linear system by an approach that incorporates a credible equivalent linearization method, a damping reduction rule and the algebraic specification of the design spectrum. The resulting closed‐form solutions obtained for the normalized response are then used to define a force modification factor for friction‐damped systems. This force modification factor, together with the condensation procedure for multi‐degree‐of‐freedom structures, enables the establishment of a quasi‐static design procedure for friction‐damped structures, which is intended for the benefit and use of structural practitioners. A curve‐fitting technique is employed to develop an explicit expression for the force modification factor used with the proposed design procedure; it is shown that this simplification results in satisfactory accuracy. Finally, a design example is given to illustrate the validation of the proposed design procedure. Copyright © 2000 John Wiley & Sons, Ltd.