Seismic energy demands on reinforced concrete moment-resisting frames

This paper examines the seismic energy demands on reinforced concrete ductile moment-resisting frames. Three frames having 4, 10 and 18 storeys, representing low, medium and tall frames, were designed to the current Canadian seismic provisions and structural design requirements. Three groups of earthquake records having different frequency contents were selected as input ground motions. The input, hysteretic and damping energies were evaluated for these three frames and correlation was established with other response parameters. The use of equivalent single-degree-of-freedom systems to estimate the energy demands on these frames was examined in order to simplify the computational effort. It is shown that the energy demand concept together with the equivalent single-degree-of-freedom system is a viable design approach for low-rise frames. Additional research to allow for the higher modal effect is required before the same concept can be extended to medium and tall frames.     

南海珠江口盆地白云凹陷现今地温场与新生代构造—热演化特征

位于南海北缘的珠江口盆地深水区作为我国海洋油气勘探的重点区域,具有良好的油气勘探前景。本文利用钻井地热测量数据分析了珠江口盆地深水区现今地温场及岩石圈热结构特征,通过古温标反演和拉张盆地模型正演相结合的方法定量揭示了白云凹陷新生代以来的热史,总结了不同地热地质条件对油气生成的影响。研究结果表明：珠江口盆地大地热流分布特征具有北低南高的特点,同时具有“热幔冷壳”的特征。珠江口盆地深水区始新世以来经历了两期拉张过程,第一期（47.8～33.9 Ma）拉张自始新世发生,拉张强度较大,凹陷中心基底热流快速上升至～82 mW/m²;第二期（23～13.8 Ma）拉张发生于中新世,此次拉张在白云凹陷南部更强烈,白云凹陷主体在 13.8 Ma达到最高古基底热流,此后进入热沉降阶段,基底热流值一直缓慢下降。磷灰石裂变径迹、磷灰石（U-Th）/He及锆石（U-Th）/He联合反演给出了最高古地温在13.8 Ma附近达到,后期温度基本稳定。     

山西中南部地区地壳深部地球物理场异常与地震

对山西中南部地区的地壳结构、地球物理场异常和地震活动性进行了综合研究,结果发现:临汾北部和太原南部的灵石、介休一带,仍存在发生中强地震的深部构造背景,今后应给予足够重视．      

韧性剪切作用下千枚岩中SiO2的迁移模拟实验—以金山金矿为例

实验较好地模拟了韧性剪切作用过程中ＳｉＯ２“释放－局部迁移”的迁移过程。实验结果表明：４００℃条件下,绢云母,绿泥石等矿物在韧性剪切作用下分解,解释出大量ＳｉＯ２,在成矿流体的参与下发生局部迁移,聚集。要使ＳｉＯ２发生大规模的迁移,富集,还需要一个相对开放的环境（如脆性剪切变形）。     

中国大陆地磁学特征与百年地震相关关系分析

鉴于我国目前正面临着本世纪第五个地震活动期,探索地震的发生规律,是个很重要的地学问题。作者在前期工作的基础上,提取了不同分量、不同阶次的区域地磁异常的特征线,并对比了 ２０ 世纪以来大地震（ Ｍｓ≥６０）的分布,发现大地震多数分布在特征线上,特别是交叉点处。说明这些特征线反映了地壳深部构造特征,故对中、长期地震预报将起到重要作用。     

浙江湖州地区膨胀土特征探讨

文章通过膨胀土的分布、成因类型、成分和结构特征及物理、力学性质的分析 ,证实膨胀土并非是理想的持力层     

Windows下静止卫星云图处理软件

使用可视化开发工具在微软Windows操作系统下开发了一套针对科研和教学使用的GMS-5静止卫星云图处理软件,它使用方便灵活,基本功能完备,能够完成气象研究中对静止卫星云图处理的基本要求。该软件的主要功能有：云图叠加地图与经纬网格、亮温等值线处理、云图平均、云图数字增强、云图转存为常用格式图像文件等。     

A remote sensing model for monitoring soil evaporation based on differential thermal inertia and its validation

To develop geosciences quantification and multi-dimensional researches will be an inevitable trend in the 21st century. The interaction between the land surface and the atmosphere not only serves as an important component in geosciences quantification, bu…     

Denudation rates of crystalline rock in the Huangling anticline of the Three Gorges of the Yangtze River in China since the Eocene

The processes and rates of the weathering denudation of the bare crystalline rock are important problems in the field of geosciences[1—6]. Essentially, the weathering denudation process is the process of rock destruction and transportation. In different …     

Morphological response of tidal marshes,flats and channels of the Outer Yangtze River mouth to a major storm

Systematic morphological changes of the coastline of the outer Yangtze River mouth in response to storms versus calm weather were documented by daily surveys of tidal marshes and flats between April 1999 and May 2001 and by boat surveys offshore during this and earlier periods. The largest single event during 1999 to 2001 was Typhoon Paibaian, which eroded the unvegetated tidal flat and lower marsh and led to accretion on the middle-to-upper marsh and in the subtidal channel. The greatest erosion of 21 cm occurred at the border between the marsh and the unvegetated flat due to the landward retreat of the marsh edge during the storm. Strong waves on the flats increased suspended sediment concentration by 10–20 times. On the upper marsh, where the frequency of submergence by astronomical tides is only 3%, Typhoon Paibian led to 4 cm of accretion, accounting for 57% of the net accretion observed over the 2-yr study. Typhoon Paibian led to 4 cm of accretion, accounting for 57% of the net accretion observed over the 2-yr study. Typhoon Paibian and other large storms in the 1990s caused over 50 cm of accretion along the deep axis of the river mouth outlet channel. During calm weather, when hydrodynamic energy was dominated by tides, deposition was centered on the unvegetated flats and lower, marsh with little deposition on the high marsh and erosion in the subtidal channel. Depositional recovery of the tidal flat from typhoon-induced erosion took only several days, whereas recovery of the subtidal channel by erosion took several weeks. A conceptual model for the morphological responses of tidal marshes, flats, and subtidal channels to storms and calm weather is proposed such that sediment continually moves from regions of highest near-bed energy towards areas of lower energy.