Morphological responses of<Emphasis Type="Italic">Limnocythere inopinata</Emphasis> (Ostracoda) to hydrochemical environment factors

Living ostracod and hydrochemical samples were collected synchronously from more than 50 lakes and small water body in the eastern edge area of the Tibetan Plateau, Northern Tibetan, Southern Tibet and mid-Tibet. The comparison of the adult body length ofLimnocythere inopinata and hydrochemical parameters of their habitats shows that a quantitative relationship exists between the adult body length and salinity expressed as conductivity. An empirical formula to reconstruct paleosalinity is suggested first and applied to salinity reconstruction of CE-2 core from Cuoe Lake, Tibet. The method is verified by comparing its outcome with results of other environment reconstruction methods.     

Morphological responses ofLimnocythere inopinata (Ostracoda) to hydrochemical environment factors

Living ostracod and hydrochemical samples were collected synchronously from more than 50 lakes and small water body in the eastern edge area of the Tibetan Plateau, Northern Tibetan, Southern Tibet and mid-Tibet. The comparison of the adult body length ofLimnocythere inopinata and hydrochemical parameters of their habitats shows that a quantitative relationship exists between the adult body length and salinity expressed as conductivity. An empirical formula to reconstruct paleosalinity is suggested first and applied to salinity reconstruction of CE-2 core from Cuoe Lake, Tibet. The method is verified by comparing its outcome with results of other environment reconstruction methods.

     

Numerical investigation of the seismic response of a UHV composite bypass switch retrofitted with wire rope isolators

An ultra-high voltage(UHV)composite bypass switch(BPS)faces increasing seismic challenges when UHV projects extend to high seismic intensity areas.The UHV composite BPS still generates excessive stress at the bottom section although hollow composite insulators with high flexural strength are adopted.Since the standard retrofitting strategy by using stiffer supports cannot reduce stress responses,wire rope isolation is introduced.The optimal design of isolation considers both stress and displacement responses since the slenderness and composite material of insulators contribute to significant displacement.The results show that properly designed isolation can significantly reduce stress without excessive displacement responses.A larger radius configuration helps to improve the applicability of small stiffness isolators under high winds.When the isolation still cannot satisfy the requirement,smaller stiffness isolators with a larger radius,or isolators with increased loops and smaller radius,can be introduced to gain better energy dissipation capacity and effectiveness in response mitigation.Accordingly,a three-step design procedure is proposed to increase the damping force but fix the rotational stiffness of isolation.Hence,the application of wire rope isolation can be extended to UHV composite BPS with a low natural frequency,but conductors with enough redundancy should be used.     

The impacts of base level and lithology on fluvial geomorphic evolution at the tectonically active Laohu and Hasi Mountains,northeastern Tibetan Plateau

Previous researches had emphasized tectonic impacts on the fluvial system at the tectonically active areas, while the effects of lithology and local base level change have received relatively rare attention. Here we investigated fluvial landforms at different spatial scales, focusing on knickpoints and channel network reorganization from an area affected by the Haiyuan Fault in the northeastern Tibetan Plateau. The geomorphic indices, i.e., drainage pattern and χ anomalies, were calculated and investigated. The results show that two regional radial drainages formed around the Laohu and Hasi Mountains. Within the interior of the radial drainage, tributaries from the southeast side of the Laohu Mountain experienced near 180° direction change.We interpret this as the gradual drainage capture originating from the height difference(～190 m) of the local base level between the two catchments. Some tributaries from the Hasi Mountain show alternating gorges and broad valleys controlled by lithology.Besides, tectonic uplift and the lowering of base level(from the incision of the Yellow River) triggered an autogenic positivefeedback transition from parallel to dendritic drainage patterns. These observations suggest that base level change and lithology play a crucial role in landscape evolution, even in a tectonically active region.     

Reflection and transmission of seismic waves at an interface betwen two saturated soils

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1996年阿图什6.9级地震参数与宏观震中

对通过计算机定位得到１９９６年３月１９日阿图什６．９级地震基本参数的可靠性进行了分析与论证，并对该次地震微观震中与宏观震中差异较大的原因进行了探讨。     

青藏高原北部地区强震演化过程研究

研究了青藏高原北部地区≥ 7级地震时空分布特征、孕育演化过程,并探讨了物理解释。结果表明,本地区≥ 7级地震空间上受区内主要活动断裂控制,发震间隔时间具有一定的规律性;同时,本地区≥ 7级地震的孕震演化过程具有共性行为,表现为孕震构造10年尺度的大范围中强震平静,研究区2～ 5年尺度的中强震频发,末次中强震的时空任意性等特征,对区域地震分析预报具有实用价值。     

我国近年水库地震监测综述

在较完整地收集我国水库诱发地震震例的基础上,回顾了我国水库诱发地震监测的成长进步厍程。本文认为无线遥测组网和计算机实时处理方式是我国近年水库诱发地震监测的主流,数字化则是其发展方向。作者提出了按地震监测系统的主要特征。对水库地震监测台网分类划代方法,将我国已客在建的水库地震监测台网划分四代。本文较详细地介绍了近年建成投测的二滩,大桥、小浪底和李家峡等第三代水库遥测地震台网的基本情况。对正在设计建设     

7 诱发地震

诱发地震为第六专题,共征集论文9篇,数量较少.然而,诱发地震研究,尤其是水库诱发地震研究是大会主持单位印度国家地球物理研究所(NGRI)的强项,所以倍受大会重视.大会主席NGRI的所长H.K.Gupta在开幕式后的特邀报告中,花了近一半时间讲述了世界闻名的印度柯依纳水库诱发地震的30年研究历史和近期的研究成果.     

深部地应力探测技术理论探讨

地应力测量的研究已有几十年的历史,但是对于地下深部地应力非钻孔式测量探测技术的发展,则一直进展很慢。本文依据天然电磁波场源,利用光弹实验模型原理,研制了ＤＹＬ型地应力探测仪,并在淮南地区地庆力状态普查过程中,取得了明显的应用效果。