The enhanced spectrum of the symbiotic variable star CH Cygni on November 2, 2006     

Kye Hwa Yoo   《New Astronomy》2010,15(2):215-226

The symbiotic variable star CH Cygni went on the deepest minimum phase in December 2006. A high-resolution spectrum of CH Cygni obtained at the Bohyunsan Optical Astronomy Observatory (BOAO) on November 2, 2006, is reported. The spectrum of CH Cygni obtained at the BOAO was calibrated on a scale of an absolute-flux density. Emission lines of H I, [O III], [N II], and [S II] were strong, with several components, and Ca II, H, and K lines had P-Cygni profiles. Removal of the spectrum of the underlying M-type star from the CH Cygni spectrum was completed to obtain the true emission profiles. The radial velocities of all emission and absorption lines were measured. Some of the observed lines were also deconvoluted using multi-Gaussian functions to find the relationship between line shapes and the corresponding sources of these lines. The results obtained are discussed in terms of an accretion disk around the hot star, and in non-spherically extended nebular regions.  相似文献   

Structural features of South-Adamawa (Cameroon) inferred from magnetic anomalies: Hydrogeological implications     

Constant Tatchum Noutchogwe  Fidèle Koumetio  Eliezer Manguelle-Dicoum 《Comptes Rendus Geoscience》2010,342(6):467-474

Structural directions of the southern part of the Adamawa plateau in Cameroon are highlighted by filters applied on the magnetic anomaly map. Determination of the magnitude maxima of (1) the horizontal gradient of the field reduced to the pole, and (2) the analytic signal, allowed a map to be produced showing various lineaments interpreted as the fault system of the studied area. In particular, the faults on the shaded relief map of the horizontal gradient magnitude suggest a slide to the left of the Foumban shear zone in the studied area. Interpretation of the observed anomaly along a profile directed SSE-NNW shows the presence of a magnetized body considered as an intrusion into the granitic basement of probably basaltic volcanic rocks, put in place during the reactivation of the Foumban shear zone. In addition, the observed correlation between the mapped structural directions, the sites of thermo-mineral springs and the hydrographical network shows that the results of this study will be helpful for further hydrogeological research in the studied area.  相似文献   

乌鲁木齐河源1号冰川年物质平衡量的预报方法与资料插补   总被引：2，自引：2，他引：2  

纪忠萍  汤懋苍 《冰川冻土》1994,16(2):128-137

本利用乌鲁木齐河源１号冰川物质平衡量实测资料、天山大西沟温度大降水、乌鲁木齐地温资源，讨论了该冰川物质平衡与某些气候要素的关系；７月气温、夏季５－７月降水及３－４月地温是控制当年物质平衡量的主要气象要素；通过寻找最佳因子，利用多元线性回归方法，建立了该冰川年物质平衡的预报公式，同时讨论了资料插补问题。  相似文献   

新疆地震综合预报判据和指标的研究     

朱令人  王海涛 《内陆地震》1989,3(3):203-213

本文在地震综合预报清理攻关及有关震例研究的基础上,根据地震孕育的阶段性,分四个时段提取了新疆地震预报实践中常用方法、手段的单项异常预报判据和指标,定性和定量地研讨了综合预报方法。提出地震综合预报的集成预测概率方法。  相似文献   

西昌发射场区旱季高空最大风的分析预报     

杨本湘 《气象》2003,29(6):22-25

根据天气学原理，对西昌发射场区旱季高空最大风环流背景和天气系统间的关系进行了分析。在此基础上，对西昌发射场区旱季高空最大风的预测进行了探讨，提出了利用常规天气图制作场区旱季高空风预报的思路和方法，找到了预报场区旱季高空最大风的部分指标。  相似文献   

Ill-conditioning and pre-whitening in seismic deconvolution     

R. J. O'Dowd 《Geophysical Journal International》1990,101(2):489-491

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Application of a data‐based mechanistic modelling (DBM) approach for predicting runoff generation in semi‐arid regions     

S. Mwakalila  P. Campling  J. Feyen  G. Wyseure  K. Beven 《水文研究》2001,15(12):2281-2295

This paper addresses the application of a data‐based mechanistic (DBM) modelling approach using transfer function models (TFMs) with non‐linear rainfall filtering to predict runoff generation from a semi‐arid catchment (795 km²) in Tanzania. With DBM modelling, time series of rainfall and streamflow were allowed to suggest an appropriate model structure compatible with the data available. The model structures were evaluated by looking at how well the model fitted the data, and how well the parameters of the model were estimated. The results indicated that a parallel model structure is appropriate with a proportion of the runoff being routed through a fast flow pathway and the remainder through a slow flow pathway. Finally, the study employed a Generalized Likelihood Uncertainty Estimation (GLUE) methodology to evaluate the parameter sensitivity and predictive uncertainty based on the feasible parameter ranges chosen from the initial analysis of recession curves and calibration of the TFM. Results showed that parameters that control the slow flow pathway are relatively more sensitive than those that control the fast flow pathway of the hydrograph. Within the GLUE framework, it was found that multiple acceptable parameter sets give a range of predictions. This was found to be an advantage, since it allows the possibility of assessing the uncertainty in predictions as conditioned on the calibration data and then using that uncertainty as part of the decision‐making process arising from any rainfall‐runoff modelling project. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Integrated 3D density modelling and segmentation of the Dead Sea Transform     

H.-J. Götze  R. El-Kelani  S. Schmidt  M. Rybakov  M. Hassouneh  H.-J. Förster  J. Ebbing  DESERT Group 《International Journal of Earth Sciences》2007,96(2):289-302

A 3D interpretation of the newly compiled Bouguer anomaly in the area of the “Dead Sea Rift” is presented. A high-resolution 3D model constrained with the seismic results reveals the crustal thickness and density distribution beneath the Arava/Araba Valley (AV), the region between the Dead Sea and the Gulf of Aqaba/Elat. The Bouguer anomalies along the axial portion of the AV, as deduced from the modelling results, are mainly caused by deep-seated sedimentary basins (D > 10 km). An inferred zone of intrusion coincides with the maximum gravity anomaly on the eastern flank of the AV. The intrusion is displaced at different sectors along the NNW–SSE direction. The zone of maximum crustal thinning (depth 30 km) is attained in the western sector at the Mediterranean. The southeastern plateau, on the other hand, shows by far the largest crustal thickness of the region (38–42 km). Linked to the left lateral movement of approx. 105 km at the boundary between the African and Arabian plate, and constrained with recent seismic data, a small asymmetric topography of the Moho beneath the Dead Sea Transform (DST) was modelled. The thickness and density of the crust suggest that the AV is underlain by continental crust. The deep basins, the relatively large intrusion and the asymmetric topography of the Moho lead to the conclusion that a small-scale asthenospheric upwelling could be responsible for the thinning of the crust and subsequent creation of the Dead Sea basin during the left lateral movement. A clear segmentation along the strike of the DST was obtained by curvature analysis: the northern part in the neighbourhood of the Dead Sea is characterised by high curvature of the residual gravity field. Flexural rigidity calculations result in very low values of effective elastic lithospheric thickness (t _e < 5 km). This points to decoupling of crust in the Dead Sea area. In the central, AV the curvature is less pronounced and t _e increases to approximately 10 km. Curvature is high again in the southernmost part near the Aqaba region. Solutions of Euler deconvolution were visualised together with modelled density bodies and fit very well into the density model structures. An erratum to this article can be found at  相似文献   

成矿理论的预测能力及其改善途径   总被引：9，自引：1，他引：9  

刘亮明 《地学前缘》2007,14(5):82-91

成矿理论预测能力决定了成矿理论的价值及其对找矿勘查的贡献。通过分析成矿理论预测能力的历史和现状,探讨了制约成矿理论预测能力的因素,并针对这些因素提出促使成矿理论预测能力提高的途径。成矿系统的复杂性和研究方法上的不足,使得应用成矿理论进行成矿预测时,既没有能完全把握成矿的本质过程及控制矿体定位的关键因素,也没能弄清勘查区域的地质特征与地质过程,还进行了条件并不充分的不严格推理,从而使得当前成矿理论的预测能力并不高。从历史的变化规律来看,任何一种成矿理论经过一段时间应用后,其预测能力是逐渐下降的;针对某一特定矿床建立的成矿模式的预测能力要比根据某一类矿床的共同特征而建立的成矿理论低得多,区域成矿的理论预测远比矿床(体)预测容易。针对创造和应用成矿理论的不足,提高成矿预测能力的途径主要有:(1)不盲目追求高新技术和新奇理论,扎扎实实做好基础地质工作;(2)发展地球信息探测技术,在更大的范围更准确地探测地球信息;(3)创新地壳构造理论,更加准确推测地壳构造时空演化特征;(4)以整体论方法研究成矿理论系统,揭示成矿作用的复杂性规律;(5)去掉多余假设,使理论的内核尽可能简单化;(6)发展地质动力学计算模拟,通过计算模拟更深入了解成矿及相关地质系统;(7)发展多源信息三维空间集成技术,实现推理计算化。  相似文献   

开封春季24h大风预报方法          下载免费PDF全文

王永铎刘茂松  李妹霞王其英 刘红雨 《气象与环境科学》2007,30(B09):37-38

利用开封1981-2000年3—5月的大风资料，依据冷空气路径，将大风分为东北型、西北型；选出预报因子，用逐步回归方法，对因子进行筛选，选出效果较好的预报因子建立方程。  相似文献