Study and application of PS-wave pre-stack migration in HTI media and an anisotropic correction method

Anisotropy correction is necessary during the processing of converted PSwave seismic data to achieve accurate structural imaging, reservoir prediction, and fracture detection. To effectively eliminate the adverse effects of S-wave splitting and to improve PSwave imaging quality, we tested methods for pre-stack migration imaging and anisotropic correction of PS-wave data. We based this on the propagation rules of seismic waves in a horizontal transverse isotropy medium, which is a fractured medium model that reflects likely subsurface conditions in the field. We used the radial (R) and transverse (T) components of PS-wave data to separate the fast and slow S-wave components, after which their propagation moveout was effectively extracted. Meanwhile, corrections for the energies and propagation moveouts of the R and T components were implemented using mathematical rotation. The PS-wave imaging quality was distinctly improved, and we demonstrated the reliability of our methods through numerical simulations. Applying our methods to three-dimensional and three-component seismic field data from the Xinchang-Hexingchang region of the Western Sichuan Depression in China, we obtained high-quality seismic imaging with continuous reflection wave groups, distinct structural features, and specific stratigraphic contact relationships. This study provides an effective and reliable approach for data processing that will improve the exploration of complex, hidden lithologic gas reservoirs.     

Field testing of the surface electromagnetic prospecting system

To test the performance of the Chinese whole-surface electromagnetic prospecting (SEP) system, system integrations, instrument performances, and large-scale production viabilities in Liaoning province and Inner Mongolia were measured via extensive field tests. Resultant electric fields, magnetic fields, apparent resistivities, impedance phases, and inversion profiles compared favorably with results of commercial equipment from other countries. The inversion results agreed well with the geologic information from boreholes. Field tests showed that the SEP system is stable, reliable, lightweight, and easy to operate, making it suitable and ready for real-field exploration.     

全国大范围异常偏暖 北方冬麦区旱情发展——1999年1月

１月,全国大部地区气温明显偏高,尤其是东部农业区偏暖异常明显。北方冬麦区大部雨雪稀少,旱情持续或发展;南方中下旬阴雨天气较多,部分地区出现雪灾、冻害。部分地区出现大雾或沙尘暴等恶劣天气。１全国大范围异常偏暖本月全国大部分地区明显偏暖。其中,东部农业区...     

云南8月气温与春季气温场的典型相关分析

利用典型相关理论,分析了云南８月低温与当年春季气温场之间的关系,得出了一些有意义的结果。春季影响云南的西风带南支槽、副热带高压和北方南下冷空气等天气系统的强弱（南支槽的强和弱用滇西气温的负距平和正距平表示,副热带高压的强和弱用滇东南气温的正距平和负距平表示,冷空气的强和弱用滇东气温的负距平和正距平表示）与８月份云南是否出现低温天气关系较大,８月份云南北部和西部出现低温天气与２月份冷空气和南支槽的强     

降雹前大气层结稳定状态下的环境场特征

分析了１９８３年９月４日巴盟地区降有大气层结稳定的降雹过程,通过对降雹前后高空槽的变化、能量条件、触发机制以及环境风垂直切变等物理量的分析,揭示了此类降雹的大气环境场地特征。同时指出在特定的环流背景下大气层结随时间的变化可能会由稳定状态变为不稳定状态。     

THE INFLUENCE OF PHOTOCHEMICAL PROCESS ON THE ATMOSPHERIC WAVE*

The time damping rate of gravity wave in the range of 30-70 km is calaclated in three circumstances:(1) adiabatic process,(2) diabatic process caused by atmospheric cooling,and(3) diabatic process resulting from atmospheric photochemical heating and cooling.The results indicate that the photochemical heating is as important as Newtonian cooling and its contribution to the time damping rate of gravity wave can not he negligible.     

云南暴雨涡散场动能转换函数的动态分析

对1996年云南主汛期（6－8月）逐日散度风动能和旋转风动能之间的转换函数C（KD,KR）特征进行深入研究,同时分析了C（KD,KR）各项Af、Az、B、C在动能转换函数中所起的作用。研究结果表明,对流层内C（KD,KR）＞0,同时对流层低层的C（K,KR）＞中高层的C（KD,KR）之和．极易出现暴雨过程;Af项在整个动能转换中起主要作用,71％的Af与C（KD,KR）具有相同的符号,Az项和B项在动能转换中起振荡作用,Az＋B控制着29％的动能转换方向。     

Adjoint Matching Condition for Parameterized Discontinuities－A Derivation Using Lagrangian-form Costfunction

The generalized adjoint property and adjoint matching condition for systems that contain discontinuous on / off switches are derived by a perturbation analysis of the Lagranging-form costfunction     

青海黄南地区近54年蒸发量变化特征及其影响因子

利用青海省黄南地区近54a(1960—2013年)蒸发量、气温、降水量、日照时数、水汽压等资料,应用地理信息系统、数理统计、线性回归和Mann-Kendall检验等方法分析了黄南地区蒸发量的空间及时间变化趋势,并对黄南地区蒸发量变化特征及其影响因子进行了诊断研究。结果表明:黄南地区年平均蒸发量呈明显的下降趋势,20世纪60—70年代为蒸发量偏多阶段,80年代及后为偏少阶段;黄南地区蒸发量最大的季节是春季和夏季,各季蒸发量均呈减少趋势;黄南地区年蒸发量在1973年发生了由多到少的突变,春、夏、秋、冬季分别发在1973、1975、1976和1974年;分析影响蒸发量的相关因子,蒸发量与日照时数呈显著的正相关关系,与水汽压和降水量呈显著的负相关关系,日照时数的减小是蒸发量减少的主要影响因子。