遗迹化石在层序地层学研究中的应用

以济阳坳陷古近系沙河街组和塔里木盆地志留系为例,探讨了遗迹化石与层序地层学的关系,表现在3个方面:1)层序界面的识别层序界面位置发育有特征性的受基底控制的遗迹相,且界面上下遗迹组合类型发生变化;2)准层序界面的识别较深水环境中,界面上下生物扰动强度明显差异,界面之下扰动强度较大,扰动指数可达到3,而界面之上几乎没有生物扰动,且在同一准层序内部,由下至上,扰动强度逐渐增大;3)旋回层序的识别:在潮控滨线环境中,单个准层序内部,由下至上,高能环境的Skolithos遗迹组合逐渐变为中低能环境的Planolites-Palaeophycus遗迹组合和低能环境的Cochlichnus-Planolites遗迹组合,由下至上呈现旋回性变化特征。     

山东高岭土矿成矿特征及成矿规律探讨

山东省已发现高岭土矿床18处,分为沉积型和风化残积型2种类型.沉积型高岭土矿受沉积作用的控制,石炭系-二叠系是其主要赋矿层位,广泛发育于鲁中地区北部的各煤田中.风化残积型高岭土矿则以中、小型矿床和矿点的形式零星分布于鲁南和鲁东各地.本文总结了山东省高岭土矿的成矿特征和成矿模式,通过典型矿床详细介绍了高岭土矿的矿体特征和...     

二维有限元大地电磁正演模拟在Matlab上的实现

Matlab高级语言开发平台对矩阵的计算简便快速,并且绘图输出文件方便。以这些特点为契机,在Matlab平台上,讨论利用有限单元法实现二维大地电磁正演的问题,推导出相应的公式,计算地表或海底视电阻率及相位,并与解析解以及主流方法结果对比,证实了本文方法的正确性。     

密肋复合墙体的地震损伤极限概率分析

密肋复合墙体是密肋壁板结构体系的主要承载构件,本文根据32块密肋复合墙体在单调及低周往复循环荷载作用下的试验结果,结合我国现行规范的目标性能,提出了针对密肋复合墙体的三个损伤性能水平及相应的量化参数,研究了这种新型墙体的损伤模型及各性能水平的允许极限破坏指标的概率特性。结果表明,采用四种地震损伤模型计算的墙体屈服、极限、破坏状态的损伤指数,在给定的显著性水平下分别服从正态分布、对数正态分布或极值Ⅰ型分布,并得到了分布的统计参数,可为该类墙体基于损伤性能的可靠度分析提供依据和参考。     

Trust-region based instantaneous optimal semi-active control of long-span spatially extended structures with MRF-04K damper

In the field of civil engineering, magnetorheological fluid （MRF） damper-based semi-active control systems have received considerable attention for use in protecting structures from natural hazards such as strong earthquakes and high winds. In this paper, the MRF damper-based semi-active control system is applied to a long-span spatially extended structure and its feasibility is discussed. Meanwhile, a _trust-region method based instantaneous optimal semi-active control algorithm （TIOC） is proposed to improve the performance of the semi-active control system in a multiple damper situation. The proposed TIOC describes the control process as a bounded constraint optimization problem, in which an optimal semi- active control force vector is solved by the trust-region method in every control step to minimize the structural responses. A numerical example of a railway station roof structure installed with MRF-04K dampers is presented. First, a modified Bouc- Wen model is utilized to describe the behavior of the selected MRF-04K damper. Then, two semi-active control systems, including the well-known clipped-optimal controller and the proposed TIOC controller, are considered. Based on the characteristics of the long-span spatially extended structure, the performance of the control system is evaluated under uniform earthquake excitation and travelling-wave excitation with different apparent velocities. The simulation results indicate that the MR fluid damper-based semi-active control systems have the potential to mitigate the responses of full-scale long-span spatially extended structures under earthquake hazards. The superiority of the proposed TIOC controller is demonstrated by comparing its control effectiveness with the clipped-optimal controller for several different cases.     

基于连续消光特征分析的岩石薄片分析系统

连续消光是指在正交偏光显微镜下,岩石薄片随载物台旋转而发生消光强弱连续变化的现象.作为人工鉴定岩石薄片的重要依据,提取后的连续消光特征可以用于实现岩石薄片的自动分析.结合数字图像处理技术与聚类划分算法,开发出一套能够分割出孔隙、颗粒轮廓,实现颗粒类别划分,并对结果做定量分析的岩石薄片分析系统.从矿物的消光特征本质出发,...     

西安市城市资源压力与城市化水平的灰色关联分析

统计结果显示西安城市化水平的提高也伴随着城市资源压力的加大,为了找出它们之间定量的数字特征关系,运用综合评价法对西安市近15年的城市化水平进行了测度.同时,使用资源压力指数法对西安市城市资源压力进行了定量评价,最后,用灰色关联分析方法对城市资源压力指数与城市化水平的各相关因子之间的关系进行研究.结果表明,城市资源压力与最能体现城市化发展水平的"城市现代化水平"因子之间存在着极强的关联,针对这一现状,提出了缓解城市资源压力和协调加快城市化发展进程之间矛盾的几点建议.     

Pollution trend in the tumen river and its influence on regional development

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Electrochemical corrosion behavior of hot dip coating in artificial seawater

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加氯水体有机浓集物对团头鲂血液指标的影响

本文对团头鲂 2项血液学指标 (红细胞数 RBC和血红蛋白量 Hb)的正常值进行了研究 ,同时检测了加氯水体中有机浓集物对这 2项指标的影响。结果表明 ,团头鲂血液中 RBC和 Hb的正常值受生长和水温等因素影响 ;在相同的试验条件下 ,加氯水体中的有机浓集物对团头鲂血液 RBC和 Hb有抑制作用 ,抑制率分别为 4 .3 %～ 2 6.0 %和 5.0 %～ 2 2 .5% ,表明此类物质对鱼类正常的生长代谢有一定的危害。