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341.
342.
本文试图解释用BP神经网络解界面反问题时效果不佳的原因。文中首先从信息量的角度提出了BP神经网络训练本集容量的概念,给出了它的定义及组织训练样本集时应遵循的原则和方法。对于如何用BP神经网络解界面反问题,给出了其基本步骤,并根据上述训练样本集容量的概念及界面反总理的特殊性,给出了组织界面反问题训练样本集的方法。 相似文献
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344.
Zhang Guomin Geng Lumin and Shi YaolinCenter for Analysis Prediction Beijing China 'Graduate School Academia Sinica Beijing China 《中国地震研究》1995,(1)
Based on the study of activity of earthquakes with M**********>7.0 in mainland China,we have found a dynamic pattern,i.e.,the cyclic characteristics in time and migration from one seismic zone to another in space.In order to understand the physical mechanism of this pattern,we use a nonlinear dynamic model to simulate the seismic activity in fault zones under a unified tectonic stress field.The basic elements in our model consist of a Maxwell body and a rigid sliding block.Basic elements in a column represent a fault,and coupling elements connecting different columns simulate the interaction among faults and fault segments.The results provide insights to the cyclic activity of strong earthquakes and to the feature of mutual influence between strong earthquakes in groups in the climax of seismic activity. 相似文献
345.
作者介绍了在多年地面信息资料处理中积累的关于浅层地温误读的分析与判断经验,总结出人机结合的5个分析判断方法,在工作中收到了良好效果,从而保证了信息资料和气表资料的准确性。 相似文献
346.
Tao Zuyu Wang Hongqing Bai Jie Zhu Wenqin Shi Dingpu Yang Hongmei 《Acta Meteorologica Sinica》1995,9(2):184-189
A case of mesoscale convective complex(MCC) which evolved into a vortex is documented in this paper.As the MCC entered into the dissipating phase,a well-defined spirally banded structure became visible in the satellite image.The blackbody temperature(TBB) of the residual cold-cloud-shield indicates the vortex existed in the layer from 400 to 250 hPa.According to the upper air analysis,the upper level vortex was an anticyclone.The MCC-generated vortex was visualized in the satellite images because it was located in the subtropical high where the wind field was very weak. 相似文献
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348.
Based on the fluorescence microscopic study, organic compositional analysis and simulating experiments on core samples and
cuttings in the Suqiao area, it is found that the Carboniferous-Permian coal-bearing formations have substrata rich in spore,
cuticle, resin and bark. These substrata have high potential for hydrocarbons, with S1 + S2 high up to about 200, high productivity of liquid hydrocarbons (73.5 mg / g or more) and natural gases (up to 194 ml / g).
The substrata are thought to be an important source for natural gases and condensates found in this area.
According to biomarker compounds and carbon and hydrogen isotope data from the Suqiao natural gas-condensate field, the coal
and its simulating products, characteristics of coal-generated gases and oils from a special kind of coal and their correlation
methods are discussed in the paper.
In terms of the geochemical conditions of formation the distribution regularities of paralic coal rich in hydrogen, the commercial
prospects of Carboniferous-Permian coal-generated oils have been evaluated as well. 相似文献
349.
A great wealth of analytical data for fluid inclusions in minerals indicate that the major species of gases in fluid inclusions are H2O, CO2, CO, CH4, H2 and O2. Three basic chemical reactions are supposed to prevail in rock-forming and ore-forming fluids: $$\begin{gathered} H_2 + 1/2{\text{ O}}_{\text{2}} = H_2 O, \hfill \\ CO + 1/2{\text{ O}}_{\text{2}} = CO_2 , \hfill \\ CH_4 + 2{\text{O}}_{\text{2}} = CO_2 + 2H_2 O, \hfill \\ \end{gathered} $$ and equilibria are reached among them. \(\lg f_{O_2 } - T,{\text{ }}\lg f_{CO_2 } - T\) and Eh-T charts for petrogenesis and minerogenesis in the supercritical state have been plotted under different pressures. On the basis of these charts \(f_{O^2 } ,{\text{ }}f_{CO_2 } \) , Eh, equilibrium temperature and equilibrium pressure can be readily calculated. In this paper some examples are presented to show their successful application in the study of the ore-forming environments of ore deposits. 相似文献
350.
Shi Li 《中国地球化学学报》1982,1(4):409-420
The lens-shaped Miaoya carbonatite complex, located west of the Wudang massif, Hubei Province, consists of several types of carbonatites associated with syenites. According to their composition, the carbonatites can be classified into four types, i. e., sovite, alvikite, carbon-bearing alvikite and ankeritic carbonatite. Their average composition is in agreement with the abundance values for carbonatites compiled by Gold (1966). There are three stages recognizable: the earliest sovite and alvikite followed by carbon-bearing alvikite, with ankeritic carbonatite being the latest. Some rules dominating the distribution of major and rare elements are observed with respect to the evolution of these carbonatites, for example, Nb is essentially enriched in sovite. Except for niobite and ilmenorutile, there are also pyrochlore, nioboeschynite and fersmite. RE are concentrated mainly in ankeritic carbonatite, within which bastnasite, parisite and monazite are found. In general, Ca, Nb, and Sr decrease, while Fe, Mg, Mn, and RE increase from earlier to later stages. It is suggested that the carbonatites are genetically connected with syenitic magma. 相似文献