海河流域沉降区地下水资源承载力评价指标体系   总被引：2，自引：0，他引：2  

董克刚  王威  于强  易长荣  周俊 《地下水》2008,30(4):12-15

海河流域大部分地区资源性缺水,历史上过度开采地下水导致了一系列的地质环境灾害,尤其是流域东部天津地区的地面沉降问题,是经济社会发展和地下水资源承载力不相协调调的具体表现。在有效进行地下水资源管理来防治地面沉降的过程中,面临的首要问题之一就是地下水资源承载力的评估。探讨了此前天津地区地下水环境容量指标在地下水资源承载力评价中的局限性,并提出“土水比”评价指标,构建“土水比”指标体系。  相似文献   

一种高性／价比的有线传呼器的设计     

江伯华 《成都信息工程学院学报》1996,(Z1)

介绍利用８０３１单片机及外围电路，设计高性／价比的有线传呼器的设计思想、技术性能及设计技巧，给出了程序框图及部分电路图。  相似文献   

Time Series Analysis on the Ratio for Pixels with Abnormal Brightness Temperature Increase and Its Variation Before Some Earthquakes with Ms ≥ 5.0 in the Taiwan Area     

Liu Fang 《中国地震研究》2007,21(4):437-444

In the study of the application of MODIS satellite remote sensing data to earthquake prediction, the paper puts forward for the first time a quantitative method to estimate the ratio for the pixels with abnormal brightness temperature (BT) increase and a preliminary scheme for cloud removal. The principle is that, firstly, the cloudless data observed by the same satellite at the same period of time but in different days (usually 1 day to 3 days) are mosaiced to get high ratio of clear sky, and then the BT variation curve and mean square difference (MSD) of each pixel are calculated with the data from the covered area to determine daily whether the BT data of the day is normal or not at a certain pixel by using double the MSD as the criterion. The ratio for the pixels with abnormal BT increase can be calculated by dividing the total number of abnormal pixels with the total pixels of the whole area. Analysis on a series of recent earthquakes in the Taiwan area shows that the ratio for pixels with abnormal BT increase, which normally undulates around zero, has a sudden enhancement 1 day to 20 days before medium-strong earthquakes. It is expected that a new method for identifying earthquake auspice could be found through special studies in regions with frequent seismic activity by analyzing the change of the ratio for the pixels with abnormal BT increase from MODIS satellite remote sensing infrared (IR) information from which the effect of clouds has been removed to a certain extent.  相似文献   

伽师地震序列的地震波谱变化研究     

夏爱国  赵翠萍 《内陆地震》2007,21(4):316-326

利用新疆伽师震区附近的喀什、乌什、巴楚3个数字台记录到的伽师地震序列波形资料,开展地震波谱研究。首先分析了伽师6.8级地震序列各台的地震波拐角频率及其比值的时序变化特征,然后从中选出对这3个台都有较好记录的66个地震事件,进行拐角频率比时序变化特征的对比研究。结果表明,这3个台的拐角频率及其比值在伽师6.8级地震前后都出现了不同的变化趋势,尤以比值的变化更为明显,而且不同台站间的变化趋势存在较为明显的差异。最后讨论了这些差异可能存在的一些原因。  相似文献   

Experimental Research on the Load／Unload Response Ratio （LURR） Theory     

Yu Huaizhong  Yin Xiangchu  Liang Naigang  Xia Mengfen  Li Min  Xu Zhaoyong  Peng Keyin  Victor Kukshenko  Wu Zhishen  Qi Li  Surguei Elizarov 《中国地震研究》2003,17(3):227-235

Implementing acoustic emission experiments with large rock samples, LURR (Load/Unload Response Ratio) theory was studied. The loading conditions in the experiments were designed to simulate the complicated loading process of underground rocks. The damages emerging inside the rock samples were recorded by the acoustic emission technique during the loading process. The experimental results were consistent with prediction by LURR theory. Integrating the changing processes of LURR value Y and the location process of acoustic emission events showed agreement between the variation of LURR value Y and the damage evolution inside the rocks. Furthermore, the high value of Y emerged before the complete breakdown of materials. Therefore, the damage evolution of rock specimen can be quantitatively analyzed with LURR theory, thus the failure of the rock materials and the earthquake occurrence may be predicted. The experimental results gave a further verification of LURR theory.  相似文献   

江苏高邮地磁台地磁异常与地震关系的研究     

蒋延林  赵卫红  王福才  张骞 《山西地震》2005,(2):19-21,35

应用加卸载响应比法、日变幅逐日比法及空间相关分析法，分析研究了江苏高邮地磁台1992年至1997年地磁垂直分量的观测资料，结果发现，在中强地震前高邮台的地磁场存在明显的磁异常变化。提出了适用于高邮台的地震分析预报参数。  相似文献   

江淮膨胀土自由膨胀率特征   总被引：3，自引：0，他引：3  

黄健敏  段海澎  陈善雄  余飞 《工程地质学报》2006,14(6):776-781

自由膨胀率是公路及其他行业膨胀土判别与分类的常用指标,研究自由膨胀率特征对指导膨胀土判别分类具有重要意义。本文依托皖中地区在建的合(肥)六(安)高速公路,开展了自由膨胀率及其他相关性指标的试验研究,分析了皖中膨胀土的自由膨胀率特征。研究表明:皖中地区膨胀土自由膨胀率与反映膨胀本质的指标蒙脱石含量,以及液限、塑性指数等间接性判别指标具有较好的相关性,可将其用作膨胀土判别与分类的指标;分类实践发现《公路路基设计规范》所推荐的自由膨胀率分级评判标准不能适用于皖中地区膨胀土;根据研究结果给出了具有合理分类特征的分类标准建议。  相似文献   

Strong, localised country-rock contamination and partial homogenisation of a mafic magma: An example from west central Sweden     

Anders Lindh  Anders Kjllerstrm  Zoltan Solyom 《Lithos》2006,86(3-4):212-228

A dolerite sill cutting slightly older basalt in west-central Sweden shows a strong chemical variation (54% < SiO₂ < 73%) within a restricted area (< 100 × 100 m²). The linear correlation among almost all elements is extremely high; in addition, _NdT is strongly correlated with the SiO₂ content. Least-square hyperbolic-ratio and three-element ratio modelling (common denominator) suggests that most of the chemical variation is explained by mixing and/or micro-mingling. In all, we test 407 hyperbolas, of which 402 are fitted. The five ratio pairs, which could not be fitted to a hyperbola using a least-square fitting procedure, have the ratio Th / Eu in common. Testing the goodness of fit is problematic for hyperbolic distributions; for comparing purposes we sum the distances to chords approximating the hyperbola. Mobile and immobile elements behave similarly, suggesting that no elements are lost or added from outside the system. The data suggests that already the most mafic of the analysed rocks is a mixture of the ‘normal’ dolerite and a siliceous crustal rock. A mafic magma intruded into the base of the crust, where it fractionated resulting in a decreased Mg number. The magma was then contaminated with country rocks in an intermediate magma chamber due to country rock melting; during mixing/mingling almost no fractionation took place. The contaminated rock suggests the presence of a fluid phase. This was probably a prerequisite for country-rock melting. Enrichment in some incompatible elements suggests that besides major mixing/mingling a thermochemical separation process has affected the most felsic rock enriching it in light rare earths and Zr.  相似文献   

任意比值法测深尺在SUBSITE型仪器中的应用     

刘正根  曾锡文等 《湖南地质》2002,21(1):77-80

为弥补SUBSITE型仪器未提供比值法测深功能的缺陷，特设计了“任意比值测深尺”。其原理表明，埋深是偏距的一元函数，任意选取一个比值参数d，根据实测的偏距即可确定埋深。株洲地质勘察院在江阴市城市管线普查工作中，根据上述原理设计制作了任意比值法测深尺。其制作简单，只需一把普通钢卷尺，以比值0．7为例，偏距为0．058m时埋深为0．1m。对卷尺0．058m处背面用白色油漆画上刻度并标上0．1m 即可，其余依此类推。这把卷尺背面，就成了SUBSTTE型仪器专用的比值法测深尺。实际操作中，与RD型仪器70％比值法比较，除量取偏距的米尺不同外，其余完全相同。生产实践中使用它测深约3000个点，精度很高，经受住了实践的检验。  相似文献   

陕西地区震源参数和平均应力场的研究   总被引：2，自引：0，他引：2  

杜兴信  张春生 《四川地震》1994,(2):6-11

利用陕西地区地震台网记录的小震垂直分量最大振幅比测定了陕西地区的震源参数，并用其小震断层面解反演了平均应力场。结果表明，陕西地区最大主压应力方向为北东东向，倾角中等，相对中等主压应力较大，小震断层面呈北西和北东向优势分布。分区试验表明，关中地区与全省基本一致，陕南似乎存在较大差异，其最大主压应力方向为北北西一南南东方向，中等主压应力也相对较小。  相似文献