大型直流电压发生器塔架结构地震响应分析     

楼梦麟  林巧  高珊 《震灾防御技术》2009,4(4):386-393

本文以某一大型直流电压发生器塔架结构为例,建立有限元计算模型,采用调幅正弦五波、Taft地震波、El-Centro地震波、云南澜沧地震波和正弦三波5种地震动输入,通过数值计算,讨论了不同输入地震波对于结构抗震设计的影响。结果表明,地震作用效应在这类特种结构的组合响应中起重要影响,采用调幅正弦五波、正弦三波作为地震输入,过分夸大了实际的地震作用效应。最后,对这类特种结构的输入地震动提出了相应建议。  相似文献   

弹性地基条件下狭窄煤柱岩爆的突变理论分析   总被引：1，自引：0，他引：1  

张勇  潘岳 《岩土力学》2007,28(7):1469-1476

将未采煤层视为弹性地基条件下,运用maple9.5符号运算软件解得岩梁的挠曲线方程。根据能量守恒原理得到的功、能增量平衡关系式,求得岩梁–煤柱系统作准静态形变时的平衡方程--折迭突变模型平衡方程;用折迭突变总势能函数所作的稳定性判别表明,岩爆前兆阶段岩梁–煤柱系统处于不稳定平衡状态;煤柱岩爆的条件是Cook刚度准则,该准则可以动态地用煤柱形变增大时所需外界的能量输入率趋于0来表示;计算了煤柱岩爆地震能释放量,阐明煤柱岩爆机制是由于岩梁弹性能释放量超过峰后软化煤柱形变所耗的能量。通过岩梁弹性势能变化率曲线和煤柱耗能曲线,以几何形式描述了所得研究结果。计算表明,未开采煤层刚度变化对岩梁的等效刚度影响微弱。工作面开挖和采空区增大,将显著减小岩梁刚度Ke,对煤柱岩爆有重要影响。  相似文献   

地图数据库建立和应用过程中生僻汉字的处理   总被引：4，自引：0，他引：4  

阚映红 《测绘学院学报》2000,17(1):42-45

就 1∶2 5万地图数据库建立和应用过程中所遇到的生僻汉字问题进行了深入和广泛的研究 ,解决了数字地图生产和应用中多年未能解决的难题 ,实现了计算机环境下对地图上生僻汉字的存储、检索和显示 ,极大地方便了实际应用  相似文献   

Pseudo-fractal interpolation for risk analysis     

Robert F. Shurtz 《Mathematical Geology》1992,24(1):99-128

This paper describes a new method of analyzing the risk incurred when the outcome of a decision depends on interpolated values, for example, on the flow through an aquifer sparsely sampled for permeability or on the ratio of waste to ore in a mineral deposit sparsely sampled for grade. The method uses large families of interpolations constructed between sample values using adaptations of the well-known midpoint displacement method for generating pseudo-fractional Brownian motion trajectories. The parameters defining each family are chosen interactively by specialists to incorporate their expert knowledge. Each family, or ensemble, then defines a population of values for any global characteristic (functional) such as flow rate or waste ratio. The probabilities of various outcomes are estimated by counting them and calculating their ratios. For example, if 900 out of 1000 are acceptable the chance of success is estimated to be 90%.  相似文献   

区际贸易隐含碳排放转移研究进展与展望   总被引：1，自引：1，他引：0  

李富佳 《地理科学进展》2018,37(10):1303-1313

区际贸易隐含碳排放转移是导致区际碳泄漏、碳减排权责失衡等问题的重要原因,对全球碳排放格局及碳减排效果影响重大。研究区际碳转移时空格局演化规律和内在驱动机理,研制针对性碳转移优化调控方案,对提升区域整体碳减排效率和经济生态综合效益,具有重要现实意义,近年来已引起了国内外学者越来越多的关注,逐渐成为区域可持续发展和生态经济研究的热点问题之一。本文对国内外区际碳转移的相关研究成果进行了梳理,重点总结了对中国省际隐含碳转移问题研究的进展和成果应用情况,展望了区际贸易碳转移问题未来研究的方向：进一步重视国际、省际碳排放转移间的协同研究,揭示区际碳排放转移的动态驱动力及驱动机理,探索创新基于共同责任的省际碳转移减排机制等。  相似文献   

施工企业建立安全生产管理体系的探索     

郑梅深 《中国煤炭地质》2008,(11):88-90

论述了施工企业建设现代安全生产管理体系的重要性,并总结了广东煤炭地质局建设安全生产管理体系．促进安全生产的实践经验,提出了施工企业应从以建立完善安全生产责任制为核心,健全各项规章制度．加强员工的教育培训、资金投入和安全检查五个方面为重点建立现代安全生产管理体系的思路。  相似文献   

Geochemical and mantle-like isotopic (Nd, Sr) composition of the Baklan Granite from the Muratdağı Region (Banaz, Uşak), western Turkey: Implications for input of juvenile magmas in the source domains of western Anatolia Eocene–Miocene granites     

M. Selman Aydoan  Hakan oban  Mustafa Bozcu   mer Ak&#x;nc&#x; 《Journal of Asian Earth Sciences》2008,33(3-4):155-176

The (late syn)- post-collisional magmatic activities of western and northwestern Anatolia are characterized by intrusion of a great number of granitoids. Amongst them, Baklan Granite, located in the southern part of the Muratdağı Region from the Menderes Massif (Banaz, Uşak), has peculiar chemical and isotopic characteristics. The Baklan rocks are made up by K-feldspar, plagioclase, quartz, biotite and hornblende, with accessory apatite, titanite and magnetite, and include mafic microgranular enclaves (MME). Chemically, the Baklan intrusion is of sub-alkaline character, belongs to the high-K, calc-alkaline series and displays features of I-type affinity. It is typically metaluminous to mildly peraluminous, and classified predominantly as granodiorite in composition. The spider and REE patterns show that the rocks are fractionated and have small negative Eu anomalies (Eu/Eu^* = 0.62–0.86), with the depletion of Nb, Ti, P and, to a lesser extent, Ba and Sr. The pluton was dated by the K–Ar method on the whole-rock, yielded ages between 17.8 ± 0.7 and 19.4 ± 0.9 Ma (Early Miocene). The intrusion possesses primitive low initial ⁸⁷Sr/⁸⁶Sr ratios (0.70331–0.70452) and negative ε_Nd(t) values (−5.0 to −5.6). The chemical contrast between evolved Baklan rocks (SiO₂, 62–71 wt.%; Cr, 7–27 ppm; Ni, 5–11 ppm; Mg#, 45–51) and more primitive clinopyroxene-bearing monzonitic enclaves (SiO₂, 54–59 wt.%; Cr, 20–310 ppm; Ni, 10–70 ppm; Mg#, 50–61) signifies that there is no co-genetic link between host granite and enclaves. The chemical and isotopic characteristics of the Baklan intrusion argue for an important role of a juvenile component, such as underplated mantle-derived basalt, in the generation of the granitoids. Crustal contamination has not contributed significantly to their origin. However, with respect to those of the Baklan intrusion, the generation of the (late syn)- post-collisional intrusions with higher Nd(t) values from the western Anatolia require a much higher amount of juvenil component in their source domains.  相似文献   

大型结构地震反应值模拟中的波动输入   总被引：11，自引：6，他引：11  

李山有  廖振鹏  周正华 《地震工程与工程振动》2001,21(2):1-5

解耦的时域有限元数值模拟技术在考虑土－结构相互作用的大型结构地震反应分析中的应用日趋成熟。为完善其中的波动输入技术，本提出 了一种波动输入时步数值模拟的简便方法，替换对自由场的频域计算，从而使结构反应分析可以完全通过时步数值模拟实现。同时，通过数值实现，对这一实施方案的有效性进行了检验。  相似文献   

工程地震学在中国的发展   总被引：3，自引：0，他引：3       下载免费PDF全文

廖振鹏  郑天愉 《地球物理学报》1997,40(Z1):177-191

以对一般工程结构抗震设防的地震区划研究及重大工程结构进行的专门的地震作用研究为主线，对工程地震学在中国近半个世纪的发展作了回顾和前瞻．  相似文献   

地下水系统的时变问题与预测   总被引：1，自引：1，他引：1  

徐恒力  陈植华 《地球科学》1991,16(1):35-41

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