东北区农业气候土壤资源潜力及开发利用研究   总被引：15，自引：1，他引：15  

马树庆  白亚梅 《地理科学》1995,15(3):243-252

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1991年忻州5.1级地震现场考察     

阎海歌  王国强 《山西地震》1991,(3):41-46

介绍了在忻州5.1Ms地震的现场,利用平均震害指数确定宏观震中和烈度划分的工作情况,讨论了几个村庄受害较重的原因以及收集到的宏观前兆异常,并结合构造条件分析了这次地震烈度偏低的原因。  相似文献   

华北地台北缘金矿资源潜力及金矿活化成矿论   总被引：1，自引：0，他引：1  

王义文 《吉林地质》1991,10(3):1-11

华北地台北缘金矿资源潜力巨大。区域潜在含金性是形成金矿化集中区的首要前提,通过二次活化再成矿是金矿成矿的主要机制,在成因上与太古代层状岩系有关,类型和时代各异的一系列金矿床构成了地台区特有的金矿床系列。  相似文献   

哈萨克斯坦斋桑7.3级地震前后的地下流体动力学效应   总被引：6，自引：6，他引：6  

王道 《内陆地震》1992,6(4):320-326

分析了斋桑地震前后天山地震带不同观测井的地下流体动力学及水文地球化学地震前兆和后效的异常变化特征。认为:地震流体效应具有不可逆性,不同构造带,远距离的异常变化可能与地壳区域块体构造运动有关,强震后效敏感带反映了区域应力场的加强过程,亦可发展成为新的潜在震源区。  相似文献   

场地破裂危险性分析          下载免费PDF全文

于克涛  蒋浦 《地震地质》1992,14(3):279-285

地表破裂是断裂发育地区主要的地震地质灾害。断层错动、地表破裂对结构物的破坏不是一般的抗震措施所能抵御的。因而地表破裂危险性分析日益引起工程设计人员的重视。利用地震危险性分析的原理,建立了考虑位错衰减的场地破裂危险性分析模型。利用该模型,可以了解场地在未来的有效时间内最大位错超过给定值的可能性。最后,以鲜水河断裂为例,评价了某场地的破裂危险性  相似文献   

STUDY ON SEISMOGENIC PROBABILITIES OF POTENTIAL HYPOCENTER REGIONS IN THE CENTRAL QINGHAI-TIBET PLATEAU USING A TECTONOPHYSICAL METHOD          下载免费PDF全文

Wang Shengzu 《地震地质》1993,15(1):13

A deterministic-cum-probabilistic tectonophysical method is used to estimate the hypocentral parameters and seismogenic probabilities of the potential hypocenter regions before and after the Nov. 5. 1988 earthquake (Ms =7) west of Tuotuoheyan in terms of the tectonic feature, stratigraphic structure, geoth-ermal environment, and driving background in the central Qinghai-Tibet plateau. As a result, the earth-quake risk tendency of this area is discussed  相似文献   

Investigations on the Biodegradability of Chlorinated Fulvic Acids Untersuchungen zur mikrobiellen Verwertbarkeit gechlorter Fulvinsäuren     

B. Hambsch  U. Schmiedel  P. Werner  F. H. Frimmel 《洁净——土壤、空气、水》1993,21(3):167-173

Microbial biodegradation of organic substances takes place during drinking water treatment, but also in the distribution net, if the drinking water still contains biodegradable organic substances. This phenomenon is called regrowth. The regrowth potential of a drinking water is high, when for instance ozonation is used as the last step of treatment. It was proved before, that ozonation increases the biodegradability of humic substances, which are the main fraction of organic carbon in drinking water. In this work the objective was to check, if chlorination has a similar effect on humic substances. Using the method developed by Werner of measuring the regrowth potential of a water it could be shown by dilution series with chlorinated and unchlorinated humic substances that the substrate quality of these organics is increased by chlorination. The better substrate quality is seen in the chlorinated solutions, which might contain also low molecular weight organic compounds, but also in the fulvic acid fraction after XAD-enrichment, which removes most of the low molecular weight organic compounds. The chlorination creates in the fulvic acid solutions a shift of molecular size to smaller molecules and higher polar substances, which might be the reasons for the better biodegradability. From these results it can be concluded, that chlorination produces substances, which are more easily biodegradable. But this will not produce regrowth problems as long as there is free chlorine present as a disinfectant. In contrast, when the chlorine demand is very high and no free chlorine is left, this might produce high colony counts in the distribution net.  相似文献   

Geometrical simulation studies of coastal cliff failures in liassic strata,South Wales,U.K.     

A. T. Williams  P. Davies  P. Bomboe 《地球表面变化过程与地形》1993,18(8):703-720

Three numerical models of cliff failure have been developed, based on analyses of rockfalls along the 22 km Liassic coastline of the Glamorgan Heritage Coast, U.K. Detailed field investigation of the bucklandi (limestone dominated) and angulata (mudstone dominated) Lias series at four locations confirm the veracity of the models. Translation failure was correctly predicted at the mainly limestone buttressed cliff sites in the bucklandi and at locations where the angulata series formed a high proportion of the cliff mass. Toppling was predicted for vertical and overhanging cliffs with basal undercutting. The factor of safety reduces as the ratio of undercutting depth (d) to tension fracture distance (D) from the cliff face increases. Instability can be triggered by thrust forces generated by wave/tide impact, freeze/thaw and expansion/contraction associated with clay infill. Thrust forces can be modest, ranging from 1·7 to 2·7 MN m², but can exceed the cross-joint strength as weathering proceeds.  相似文献   

Identification of Strong Earthquake Sites in Hebei Region by Making Use of Cluster Method     

Fu Liping  Ma XiufangInstiture of Geophysics. SSB 《中国地震研究》1994,(3)

The Cluster and Hamming methods are used in this paper for a comprehensive study on geology,geomorphology,geophysical field,crustal deformation,active faults,regional stress axes and their relation in Hebei region.Fourteen potential seismic zones in which shocks with M≥6 may happen have been identified.Shocks with M≥6 have occurred in seven of them,and the others have been considered as a future strong earthquake areas.Both the K value and testing of deleting nodes show the stability of results obtained in this paper.The potential seismic zones identified in the paper fall into the areas of marked risk areas within 10 years in North China,but the scale of the identified zones is smaller.The Datong-Yanggao earthquake with M-6.1 occurred in October 1989 precisely in the 14th potential seismic zone mentioned above.  相似文献   

Inversion of potential field data     

P. S. Moharir 《Journal of Earth System Science》1990,99(4):473-514

The problem of inversion of potential field data is a challenging one because of the difficulty in obtaining a unique solution. This paper identifies various types of nonuniqueness and argues that it is neither possible nor necessary to remove all categories of nonuniqueness. Some types of nonuniqueness are due to human limitations and choice and these would always persist. Listing all the solutions, imposing additional constraints on the acceptable solutions, a priori idealization, use of a priori or supplementary information, characterizing what is common to all the solutions, obtaining extremal solutions, seeking a distribution of all possible solutions, etc. are various responses in the face of nonuniqueness. It is shown that merely the form of nonuniqueness is changed by all these techniques. Some algorithms, which should be used to obtain the global minimum of the objective function are discussed. The conceptual commonality underlying seemingly different approaches and the possibility of nonunique interpretations of the same numerical results due to different axiomatic contexts are both elucidated.  相似文献