丽江大研镇震灾分布和地脉动测量结果之间的相关性   总被引：4，自引：2，他引：4  

蒋乐群  李康龙 《地震研究》1997,20(1):125-131

丽江７．０级地震后，大研镇被毁建筑物的地理分布呈显４条条带，伤亡人员的地理分布和上述条带重合。９１个短周期地脉动测点的观测资料表明，分布在上述条带内的大多数测点，其卓越周期大于０．３Ｓ；条带外的测点，其卓越周期一般在０．１Ｓ左右。作认为卓越周期和烈度异常之间良好的相关性，是因为地脉动卓越周期和地方震的频谱之间存在良好的相关性。  相似文献   

地震活动时序谱的涨落统计特征与地震活跃期   总被引：1，自引：0，他引：1  

涂鹏  韩渭宾 《四川地震》1997,(4):22-29

为寻求地震活动演化的统计判据，本文采用多项式拟合法展示地震时序谱之涨落谱，以分维函数法判断最小邻间距（NNS）分布的Poisson性，然后采用MKS无参量法判别涨落谱之统计稳定性，确定NNS分布的转变区，具体研讨了四川、云南若干震区地震活动时序谱的涨落统计分布，发现地震活跃期到来时NNS分布表现出非Poisson化的特征。进一步通过改变和调节时序数据样本集之震级下限，并逐段前推进行统计计算的方式进一步验证结果的可靠性，客观地确定了这些震区地震活动时序涨落谱统计特征的转变期，使根据该统计法判断地震活跃期的方法论渐趋完善。  相似文献   

利用生育期水分供应系数进行旱涝区划的研究     

于荣环  孙孟梅 《南京气象学院学报》1997,20(4):518-521

根据不同作物不同发育阶段的需水特性，建立了作物蒸腾耗水模型。利用水分平衡方程。根据降水量及前期土壤水分储存量与作物蒸散耗水量的差，确定作物不同生育期水分满足程度的时间变化曲线，用以衡量水分的满足程度。  相似文献   

培矮64S冷灌繁种技术研究          下载免费PDF全文

朱兰娟  储长树 《气象》1997,23(12):47-51

通过对低温敏核不育系培矮６４Ｓ育性敏感期间冷水处理后温度场分布特征和自交结实率的资料分析，得出培矮６４Ｓ的灌水始期是冷灌后的见穗期往前推１８天，终止期为见穗期往前推３天，灌水深度前１０天为１５ｃｍ，，后５天为２０ｃｍ，，为“冷繁”技术在生产上应用提供了理论依据。  相似文献   

灰色预测模型在径流长期预报中的应用   总被引：6，自引：3，他引：6  

蓝永超  杨志怀 《中国沙漠》1997,17(1):49-52

基于灰色系统的建模理论，利用河西地区有关河流的径流观测资料，建立了一个ＧＭ（１，１）残差序列周期修正径流预测模型，并用于春旱缺水期３～６月河流来水量的长期预报，经生产部门验证，准确率在８０％以上  相似文献   

Determination of the isotropic component of deep focus earthquakes by inversion of normal-mode data     

Tatsuhiko Hara  Keiko Kuge  Hitoshi Kawakatsu 《Geophysical Journal International》1996,127(2):515-528

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云南宁蒗地区喜山期斑岩带地质特征与成矿   总被引：1，自引：0，他引：1  

胡受权  郭文平 《地质与勘探》1996,32(3):7-13

斑岩带受近南北向的包都－波罗弧形断裂控制，由混源型岩浆被动侵位而成，属钙碱性系列，中酸性岩。研究表明为含铜或铜（钼）斑岩，具良好的成矿前景。  相似文献   

吉南地区马达岭组的时代重新厘定及其意义     

陈跃军  周晓东 《吉林地质》1996,15(2):27-30

吉林地区的马达岭组为一套河流相紫色、紫红色砂砾岩，前人曾先后将其置于中侏罗世、晚株罗世、新元古代、古元古代。但由于缺少直接或间接的地质证据及同位素年龄资料，故其时代问题一直悬而未决。１９９１￣１９９３年笔者等在红土崖幅（１／５万）进行区调工作，发现了青白口纪的鱼台组不整合覆于马达岭组之上，根据层序学的理论分析，马达岭组应属新元古代海侵早期深切河谷沉积。故将其时代置于青白口纪早青白口世。  相似文献   

Tectonometamorphic evolution of the Himalayan metamorphic core between the Annapurna and Dhaulagiri, central Nepal   总被引：12，自引：0，他引：12  

J.-C. VANNAY  & K. V. HODGES 《Journal of Metamorphic Geology》1996,14(5):635-656

The metamorphic core of the Himalaya in the Kali Gandaki valley of central Nepal corresponds to a 5-km-thick sequence of upper amphibolite facies metasedimentary rocks. This Greater Himalayan Sequence (GHS) thrusts over the greenschist to lower amphibolite facies Lesser Himalayan Sequence (LHS) along the Lower Miocene Main Central Thrust (MCT), and it is separated from the overlying low-grade Tethyan Zone (TZ) by the Annapurna Detachment. Structural, petrographic, geothermobarometric and thermochronological data demonstrate that two major tectonometamorphic events characterize the evolution of the GHS. The first (Eohimalayan) episode included prograde, kyanite-grade metamorphism, during which the GHS was buried at depths greater than c. 35 km. A nappe structure in the lowermost TZ suggests that the Eohimalayan phase was associated with underthrusting of the GHS below the TZ. A c. 37 Ma ⁴⁰Ar/³⁹Ar hornblende date indicates a Late Eocene age for this phase. The second (Neohimalayan) event corresponded to a retrograde phase of kyanite-grade recrystallization, related to thrust emplacement of the GHS on the LHS. Prograde mineral assemblages in the MCT zone equilibrated at average T =880 K (610 °C) and P =940 MPa (=35 km), probably close to peak of metamorphic conditions. Slightly higher in the GHS, final equilibration of retrograde assemblages occurred at average T =810 K (540 °C) and P=650 MPa (=24 km), indicating re-equilibration during exhumation controlled by thrusting along the MCT and extension along the Annapurna Detachment. These results suggest an earlier equilibration in the MCT zone compared with higher levels, as a consequence of a higher cooling rate in the basal part of the GHS during its thrusting on the colder LHS. The Annapurna Detachment is considered to be a Neohimalayan, synmetamorphic structure, representing extensional reactivation of the Eohimalayan thrust along which the GHS initially underthrust the TZ. Within the upper GHS, a metamorphic discontinuity across a mylonitic shear zone testifies to significant, late- to post-metamorphic, out-of-sequence thrusting. The entire GHS cooled homogeneously below 600–700 K (330–430 °C) between 15 and 13 Ma (Middle Miocene), suggesting a rapid tectonic exhumation by movement on late extensional structures at higher structural levels.  相似文献   

江苏煤层气资源分析     

傅学海  马筱英 《江苏地质》1997,21(2):120-123

简要地归纳了江苏省煤层气的成矿地质环境，分析了成煤区地质构造特征、煤层及围岩储层的物性特征，在此基础上，对主要地区煤层气资源进行了估算。  相似文献