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981.
滹沱河上游,代县太和岭口村附近发现新构造中,主干断裂发育在基岩山岭本与第四系之间,断面倾角较缓且略呈上陡下缓趋势。正断层的下降盘出现反向牵引的背斜和反向正断层,它不着断层水平位移量与速率同于垂向的位移量与速率。因而具有裂谷拉张过程中 镜头主低角度正断层的特点。 相似文献
982.
秦岭地区金矿成矿研讨 总被引:2,自引:0,他引:2
秦岭是著名的“中金带”,隶属古亚洲断裂体系,区内断裂构造发育,岩浆活动频繁,变质作用强烈,金的成矿类型繁多,历经勘查,综合性金属矿山相继问世。经系统研究,根据成矿规律进行了多矿种金的成矿预测。 相似文献
983.
984.
An algorithm for the solution of a nonlinear problem of phase boundary movement and evolution of temperature distribution
due to the perturbation in the basal heat flux has been discussed. The reduction of the problem to a system of nonlinear ordinary
differential equations with the help of a Fourier series method leads to a stiff system. This stiffness is taken care of by
the use of a modified Euler’s method. Various cases of basal heat flow variation have been considered to show the performance
and stability of the technique for such a nonlinear system. The first case of step-wise function is taken to analyse the performance
of the technique, and the study has been extended to other general cases of linear increase, periodic variation, and box and
triangular function type variations in the heat flux. In the step-wise case the phase boundary attains a constant position
rapidly if the supplied heat flux is sufficiently large. The effect of periodicity in the heat flow is clearly depicted in
the phase boundary movement, where the phase boundary oscillates about the mean position at large times. The absence of any
constant level in the case of linear increase in heat flux is due to a very large value of heat flux. In the cases of box
car and triangular heat flux the boundary starts moving downward after the cessation of excess heat flux but does not immediately
return to its original preperturbation state, instead approaches it at large times. This technique may be applied to more
general cases of heat flow variation. 相似文献
985.
986.
The goodness of fit of the negative binomial and the Poisson distributions to partial duration series of runoff events is tested. The data have been recorded by eight hydrometric stations located on ephemeral rivers in Isreal. For each station, a number of threshold discharges are considered, by that series of nested subsamples are formed. Owing to size limitations, a Chi-square test is conducted on samples associated with low to moderate threshold discharges. Positive results, at a 5% significance level, are obtained in 30 out of the 53 tests of the Poisson distribution, and in 22 out of the 28 tests of the negative binomial distribution. The fit of the Poisson distribution to samples of conventionally recommended sizes (of 2 to 3 events per year) is found positive for five rivers and negative for the three other rivers The fit of the negative binomial distribution to these samples is found positive for six rivers, inconclusive for one river and short of data for the eighth river. Mixed results are obtained as the threshold level is raised. Therefore, no direct extrapolation is possible to samples associated with high thresholds.An indirect extrapolation is drawn through a comparison of the actual properties of the samples with those expected under a perfect fit of the distribution functions. Ranges of such properties are defined with respect to the properties of the tested samples and to the test results. The actual properties of nine of the eleven samples associated with high thresholds (i.e. mean number of events <-0.1year
–1) are found within these ranges. This provides a hint for a probable good fit of either distribution, and particularly the negative binomial, to the occurrence frequency of high events. 相似文献
987.
辽东半岛寒武系发育良好,化石丰富,是研究寒武纪地层和三叶虫动物群的理想地区。笔者将下寒武统及中寒武统毛庄阶划分了7个生物带,其中新建立生物带1个,新划分出生物带2个,并与国内外有关地区进行对比。三叶虫动物群包括34个种,分属19个属和3个亚属。由于篇幅所限,本文只简要描述了带化石,新属、新种另文发表。 相似文献
988.
运用平稳正态序列穿过理论方法对渭河盆地和陕南地区近期的地震活动趋势进行了分析和讨论,得到了较好的结果,并对该方法的结果进行了检验。 相似文献
989.
新疆北部的改造系列花岗岩演化由斜长花岗岩阶段、钾长花岗岩阶段至碱长花岗岩阶段,其稀土配分组成递降曲线簇.新疆北部的同熔型花岗岩类稀土配分基本为轻稀土富集型,具Eu负异常,有递增曲线簇和递降曲线簇两种情况.深源碱性系列轻重稀土比值大、Eu负异常一般不显著.文中还叙述了新疆北部的幔分异系列花岗岩类及一些古老花岗岩的稀土特征. 相似文献
990.
This paper establishes the phase space in the light of spacial series data,discussesthe fractal structure of geological data in terms of correlated functions and studies thechaos of these data.In addition,it introduces the R/S analysis for time series analysisinto spacial series to calculate the structural fractal dimensions of ranges and standard de-viation for spacial series data,and to establish the fractal dimension matrix and the proce-dures in plotting the fractal dimension anomaly diagram with vector distances of fractal di-mension.At last,it has examples of its application. 相似文献