华南石炭纪岩关-大塘界线期牙形石地层分带   总被引：4，自引：0，他引：4  

田树刚  M.科恩 《地质通报》2004,23(8):737-749

系统采集不同沉积相区和连续沉积的剖面，即浅海台地相广西柳江龙殿山剖面、台缘缓坡相云南施甸鱼硐剖面和台内盆地相广西柳州碰冲剖面，运用数理统计方法，研究了华南岩关一大塘界线过渡期牙形石的产出丰度和相分布，在恢复生物演化序列的基础上，对各剖面首先详细分带，再进一步综合成系统的5个牙形石带，即Gnathodus typicus—G．cuneiformis带、Gnathodus typicus—Protognathodus cordiformis带、Scaliognathus anchoralis—Gnathodus pseu-dosemiglaber带、Gnathodus praebilineatus带和Paragnathodus horrtopunctatus带。以生物系统发生为标准，严格限定各带的界线，并与北美、西欧同期地层进行精确对比，为建立杜内阶一维宪阶界线的全球层型(GSSP)提供可靠依据。  相似文献   

横穿贝加尔湖山脉北部寒区的线性工程     

I.Y. Malchikova 《冰川冻土》2004,26(Z1):206-209

The development of North Transbaikalye mineral resources (e. g. the Chiney deposit of iron titanium-vanadium-magnetite ores and Udokan copper deposits) is impossible without the establishment of industrial and transport infrastructure, one component of which are linear engineering constructions (drive railways, by-line auto roads, platform passages, protecting constructions, and others). However,on condition of spreading permafrost rocks this is conjugated with certain ecological risk just as from the transport network objects so for the objects themselves. A special attention is paid in the paper to considering of problems of projecting and constructing railways on the Udokan ridge.  相似文献   

Estimating the seismic displacement of friction pendulum isolators based on non‐linear response history analysis     

Keri L. Ryan  Anil K. Chopra 《地震工程与结构动力学》2004,33(3):359-373

A procedure for developing equations that estimate the isolator displacement due to strong ground motion is applied to buildings isolated with the friction pendulum system. The resulting design equations, based on rigorous non‐linear analysis, offer an alternative to the iterative equivalent‐linear methods used by current U.S. building codes. The governing equations of the system are reduced to a form such that the median normalized displacement of the system due to an ensemble of ground motions is found to depend on only the isolation period—a function of the curvature of the isolator—and the friction force at incipient slip normalized by peak ground velocity. The normalization is effective in minimizing the dispersion of the normalized displacement for an ensemble of ground motions, implying that the median normalized displacement is a reliable estimate of response. The design equations reflect the significant (20 to 38%) increase in displacement when the excitation includes two lateral components of ground motion instead of just one component. Equivalent‐linear methods are shown to underestimate by up to 30% the exact median displacement determined by non‐linear response history analysis for one component of ground motion, and building codes include at most a 4.4% increase for a second component. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Approximate modal decomposition of inelastic dynamic responses of wall buildings     

C. Sangarayakul  P. Warnitchai 《地震工程与结构动力学》2004,33(9):999-1022

Two approximate methods for decomposing complicated inelastic dynamic responses of wall buildings into simple modal responses are presented. Both methods are based on the equivalent linear concept, where a non‐linear structure is represented by a set of equivalent linear models. One linear model is used for representing only one vibration mode of the non‐linear structure, and its equivalent linear parameters are identified from the inelastic response time histories by using a numerical optimizer. Several theoretical relations essential for the modal decomposition are derived under the framework of complex modal analysis. Various numerical examinations have been carried out to check the validity of the proposed modal decomposition methods, and the results are quite satisfactory in all cases. Fluctuating bending moment and shear at any location along the wall height contributed by each individual vibration mode can be obtained. Modal contributions to shear and flexural strength demands, as well as the corresponding modal properties, under various seismic loading conditions can also be identified and examined in detail. Furthermore, the effects of higher vibration modes on seismic demands of wall buildings are investigated by using the modal decomposition methods. Several new insights into the complicated inelastic dynamics of multi‐story wall buildings are presented. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

大气季节内振荡对印度洋—西太平洋地区热带低压/气旋生成的影响   总被引：24，自引：4，他引：24  

祝从文  Tetsuo Nakazaw  李建平 《气象学报》2004,62(1):42-50

文中利用EOF分析大气季节内振荡 (MJO)的时空变化的方法 ,研究了 1996年 9月～ 1997年 6月间的MJO活动对生成在印度洋—西太平洋海域的热带低压 /气旋的影响。结果发现 ,除西北太平洋之外 ,发生在其他区域的热带低压 /气旋有半数以上生成在向东移动的MJO的湿位相中。伴随MJO的向东传播 ,热带低压 /气旋平均生成位置也随之向东移动 ,而生成在西北太平洋的热带低压 /气旋分别受到向东和向西传播的MJO影响  相似文献   

油气圈闭与鄂尔多斯盆地北部铀成矿关系探讨   总被引：11，自引：2，他引：11  

孙晔  李子颖  肖新建  侯高文 《铀矿地质》2004,20(6):337-343

鄂尔多斯盆地北部的伊盟隆起区 ,特别是杭锦旗至东胜一带的地层发育大量的圈闭 ,它们是油气聚集成藏的场所。本文剖析了这些圈闭的类型和成因 ,指出它们是盆地北部天然气运移的有利指向区 ,是还原性气体的储存库和重要的扩散源 ;油气渗出和含氧含铀水渗入的交汇部位是铀成矿的有利场所。因此 ,查明圈闭和断裂构造 ,对分析油气运移方向及砂岩型铀矿预测具有实际意义  相似文献   

沉降-时间曲线呈“S”型的证明   总被引：13，自引：5，他引：13  

梅国雄  宰金珉  殷宗泽  赵维炳  殷建华 《岩土力学》2004,25(1):20-22

从一维固结理论出发，严格证明了在线性加载或近似线性加载情况下（这和工程实际加载相类似），沉降-时间曲线呈“S”型。  相似文献   

Sorption Characteristics of Rare Earth Element Eu^3＋ onto Silica-Water Interfaces Studied by Fluorescence Spectroscopy     

Yin Xiulan China Institute of Geo-environmental Monitoring  Beijing  China Hu Ping Faculty of Earth Sciences  China University of Geosciences  Wuhan  China  Northeastern Illinois University  Chicago  IL  USA Li Dien Division of Earth  Environmental Sciences  Los Alamos National Laboratory  Los Alamos  NM  USA 《中国地质大学学报(英文版)》2004,15(4):355-360

The sorption of Eu species onto nano-size silica-water interfaces was investigated using fluorescence spectroscopy for Ph ranges of 1-8.5 and an initial Eu concentration (Ceu) of 2×10-4 M. The sorption rate of Eu was initially low, but significantly increased at Ph>4. The sorption density of Eu species on a silica surface was ～1.58×10-7 mol/m2 when the dissolved Eu species were completely sorbed onto silica-water interfaces at Ph=～5.8. The sorbed Eu species at Ph<6 is aquo Eu3 , which is sorbed onto silica-water interfaces as an outer-sphere complex at Ph<5, but may be sorbed as an inner-sphere bidentate complex at 5相似文献   

基于非线性平差模型的坐标转换公式   总被引：4，自引：2，他引：4  

包欢 付子傲陈刚  王玉京 《测绘学院学报》2004,21(3):175-177

用线性近似法以及非线性参数估计法讨论了直角坐标系七参数转换模型，指出改进的Gauss-Newton方法具有理论严密、计算简洁、易于编程、精度较高等持点。对于处理类似坐标转换的非线性模型具有重要的理论和实践意义。  相似文献   

线阵推扫影像的核线模型研究   总被引：2，自引：0，他引：2  

巩丹超  张永生  邓雪清 《遥感学报》2004,8(2):97-101

通过对线阵CCD推扫式影像和框幅式中心投影影像的核线理论的对比研究，建立了线阵CCD推扫式影像的核线理论，并探讨了它的基本特性，从而为核线在线阵CCD推扫式影像中的应用提供了理论基础。  相似文献