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271.
人工合成硅灰石的发光性质与发光机理的初步研究 总被引:2,自引:0,他引:2
在254nm紫外光照激发条件下,对人工合成掺入不同激活离子的低温TC型和高温型假硅灰石的发光性质进行了实验测定,从微观原子能量谱项讨论了在全的硅灰石基质中Eu^3+和Gd^3+的发光机理,分析了Bi^3+对Eu^3+与Pb^2+对Mn^2+的敏化发光条件,初步探讨了掺放Eu^3+的高温型假硅灰石发光强度减弱的原因。 相似文献
272.
本文提供了1982年12月、1983年5月在景洪东北先后发生的5.8、5.3、5.7级地震及1983年6月莱州7.0级地震的中期、短期、临震预报的实况和主要依据。中期预报是通过∑E(1/2)释放速率变化出现异常,确定本区处于释放加速段,用最优分割等周期分析法处理得该区活动段将延迟到1983年6月底。利用地震活动位置演变确定活动地点在景洪—江城以南地区。短期预报主要根据孕震过程中依次出现的三个北东向地震条带,b值从1.3下降到0.55,并参考了省内大范围Rn值突变异常,推算出未来主震将大于6.5级。按文献[1]广义调制模式思路,确定震源体处于受调状态,进而外推对莱州7.0级地震作出临震预报。 相似文献
273.
Effect of atmospheric overlapping bands and their treatment on the calculation of thermal radiation 总被引:5,自引:0,他引:5
Shi Guangyu 《大气科学进展》1984,1(2):246-262
The effect of the overlapping band of atmospheric gases and its treatment on the calculation of flux and cooling rate due to the long wave radiation is investigated in detail by a new transmission model for overlapping bands, taking the 15 μm band of CO2 as an example. It is found that the presence of band overlapping has a quite significant influence on radiative fluxes and cooling rates in the upper stratosphere and the troposphere, in particular, at the earth's surface. However, in the middle-lower stratosphere, the overlapping effect appears to be insignificant. It is also shown that the usual wide-band transmission model treating the overlapping effect overestimates the net longwave fluxes in the lower stratosphere and, in particular, in the troposphere including the surface. But, in the middle-upper stratosphere, the contrary is the case. 相似文献
274.
In this paper a nonlinear method of time series analysis-threshold autoregressive (TAR) model in discrete time is used. The TAR procedure consists of four parts: model building, statistical identification, parameter estimation and forecasting.The object of this study is to estimate monthly total precipitation of Shanghai and Beijing by using open loop TAR model. We can see that the trend of forecasting is in agreement with observations. 相似文献
275.
276.
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
277.
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
278.
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
279.
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
280.
Shi Shi 《中国地球化学学报》1982,1(3):281-294
Volcano-sedimentary series of the Upper Jurassic to the Lower Cretaceous are extensively developed in Zhejiang Province. But ages and stratigraphic correlation concerning these rocks have long been a controversial problem. Systematic sampling was made of volcanic rocks of the Laocun, Huangjian, Shouchang and Moshishan Formations in western Zhejiang considered thus far as the Late Jurassic. Isotopic age determinations show that U-Th-Pb zircon ages are approximately concordant with Rb-Sr isochron ages, whereas K-Ar biotite ages and K-Ar isochron ages are all slightly lower. It can therefore be established that the ages of volcanic rocks mentioned above range from 134±6 to 122±2 m.y., corresponding to the “transitional period” from Jurassic to Cretaceous. It can also be concluded that the rocks have not undergone apparent epigenetic metamorphism. The initial87Sr/86Sr ratio is about 0.7089–0.7121, on the basis of which it may be postulated that the volcanic magma seems to have originated from the upper mantle with contamination by sialic materials subsequent to differentiation. For age determinations of such acid volcanic rocks Rb-Sr isochron method is considered more suitable in view of its following advantages: the high reliability of results; wide applicability to different samples; smaller sample requirement and the possibility for further studies involving petrogenesis by use of initial87Sr/86Sr ratio. 相似文献