油气田遥感影像模型及油气综合远景预测研究   总被引：2，自引：0，他引：2  

谢青云  郭德方  包绍华  兰玉琦 《国土资源遥感》1994,5(4):30-36

本文以线性体、环形体的油气田地质意义分析为基础,通过线、环共生组合规律及油气地质多因素的综合分析,提出了3个油气田遥感预测模型。利用所建立的遥感模型及其它地学模型,在济阳坳陷地区以遥感信息为主进行了微机综合油气远景预测,提出了若干远景区。实践证明,利用遥感信息进行构造分析的找油方法,对石油勘探具有重要意义,它具有简便和勘探成本低等优点。  相似文献   

天目山树轮碳同位素与周边地区旱涝变化关系的研究     

吕军  江志红  张静  钱君龙 《南京气象学院学报》2008,31(3):389-394

根据帕尔默干旱模式的基本思路,建立动态的能反应旱涝持续特征的适合于天目山地区的旱涝指数。对采自天目山的柳杉树轮进行交叉定年后,测得树轮的δ^13C年序列,将δ^13C去除大气CO2趋势影响后的高频变化与不同时段的旱涝指数进行相关分析,结果显示：春夏季的旱涝指数与当年和滞后一年的δ^13C序列有着比较显著的相关性,表明树轮δ^13C对春夏季旱涝的发生有着比较好的响应。根据此显著相关性,利用多元回归方程重建了历史时期的春夏季旱涝指数,分析表明天目山地区春夏季旱涝的发生具有比较明显的年代际变化特征,为研究该地区气候变化特征提供了较可靠的参考依据。  相似文献   

348-YEAR PRECIPITATION RECONSTRUCTION FROM TREE-RINGS FOR THE NORTH SLOPE OF THE MIDDLE TIANSHAN MOUNTAINS^*          下载免费PDF全文

YUAN Yujiang  LI Jiangfeng  ZHANG Jiabao 《Acta Meteorologica Sinica》2001,15(1):95-104

Correlation census shows that the correlation between the tree-ring chronologies in the Urumqi River Basin and precipitation during July in the last year to February in the concurrent year is significant,and the best single correlation coefficient is 0.74,with significance level of 0.0001.Using two residual chronologies collected from west Baiyanggou and Boerqingou,precipitation for 348 years can be reconstructed in the North Slope of middle Tianshan Mountains,its explained variance is 62%.According to much verification from independent precipitation data,historical climate records,glacier and other data.it shows that the reconstructed precipitation series of 348 years is reliable.Analysis of precipitation features indicates that there were three wet periods occurring during 1671-1692,1716-1794 and 1825-1866 and three dry periods during 1693-1715,1795-1824 and 1867-1969.Two wet periods,during 1716-1794 and 1825-1866,correspond to the times of the second and the third glacial terminal moraine formation,which is infront of No.1 glacier in Urumqi River source.According to computation,corresponding annual precipitation amounts are 59mm and 30mm more than now.The reconstructed precipitation series has a significant drying trend from 1716 to 1969.and has better representativeness to the precipitation of Urumqi and Changji Prefecture on the North Slope of Tianshan Mountains.  相似文献   

Aspects Of Ring Lasers As Local Earth Rotation Sensors     

U. Schreiber  M. Schneider  C.H. Rowe  G.E. Stedman  W. Schlüter 《Surveys in Geophysics》2001,22(5-6):603-611

Ring laser rotation sensors are best known from inertial navigation, wherethey have many advantages over mechanical gyroscopes. They have recentlybeen greatly improved, and show potential as fully independent length-of-daysensors. We discuss some important aspects of current limitations in theirperformance. In particular we demonstrate a novel scheme for thestabilisation of a large ring laser against frequency pulling effectsinduced by backscatter.  相似文献   

华山松树木年轮对气候响应的模拟分析   总被引：19，自引：1，他引：19       下载免费PDF全文

尹训钢  吴祥定 《应用气象学报》1995,6(3):257-264

采用树木年轮生长模型，从细胞尺度对华山松在不同时期的树木生长状况，包括早材和晚材的细胞大小等年轮结构变化进行了模拟。所建立的细胞大小年表对气候的响应函数结果，揭示出华山松的生长主要受生长季中4～7月份以及滞后一年降水的影响，而温度只是在生长季节开始的4月份起限制作用。利用气候资料对华山松的细胞大小及变化趋势的模拟结果表明，它与实测值十分接近。  相似文献   

磁共振伪影的探讨   总被引：1，自引：0，他引：1  

童双立 《CT理论与应用研究》1995,4(4):8-10

本文讨论了磁共振伪影，包括运动伪影，化学位移伪影，截断伪影，磁化率伪影和卷褶伪影。也介绍了校正和减少这些伪影影响的方法。  相似文献   

Averno tuff ring in Campi Flegrei (south Italy)     

G. Mastrolorenzo 《Bulletin of Volcanology》1994,56(6-7):561-572

The tuff ring of Averno (3700 years BP) is a wide maar-type, lake-filled volcano which formed during one of the most recent explosive eruptions inside the Campi Flegrei caldera.The eruptive products consist of (a) a basal coarse unit, intercalated ballistic fallout breccia, subplinian pumice deposits and pyroclastic surge bedsets and (b) an upper fine-grained, stratified, pyroclastic surge sequence.During the deposition of the lower unit both purely magmatic (lapilli breccia) and hydromagmatic episodes (wavy and planar bedded, fine ash pyroclastic surge bedsets) coexisted. The hydromagmatic deposits exhibit both erosive and depositional features. The upper unit mostly comprises fine grained, wet pyroclastic surge deposits. The pyroclastic surges were controlled by a highly irregular pre-existing topography, produced by volcano-tectonic dislocation of older tuff rings and cones.Both the upper and lower units show decreasing depletion of fines with increasing distance from the vent. The ballistic fallout layers, however, exhibit only a weak increase in fines with distance from the vent, in spite of marked fining of the lapilli and blocks. The deposits consist dominantly of moderately to highly vesicular juvenile material, generated by primary magmatic volatile driven fragmentation followed by episodes of near-surface magma-water interaction.The evolution of the eruption toward increased fragmentation and a more hydromagmatic character may reflect that the progressive depletion in magmatic volatiles and a decrease in conduit pressure during the last stage of the eruption, possibly associated with a widening of the vent at sea level.  相似文献   

可可西里地区错达日玛陨坑湖成因初探   总被引：2，自引：1，他引：2  

胡东生 《盐湖研究》1994,2(1):31-37

本文根据可可西里地区综合调查资料和地球资源卫星遥感信息的研究，分析了错达日玛环形构造体系网络及湖泊地貌构型特征的动力条件，从而确定了错达日玛陨坑湖的成因类型，并建立了陨坑湖形成过程的演化模式．  相似文献   

Drift loss cone instability in the ring current and plasma sheet     

K. G. Bhatia  G. S. Lakhina 《Journal of Earth System Science》1980,89(1):99-108

The drift loss cone instability, propagating nearly transverse to the ambient magnetic field, is studied in the ring current plasma taking into account the relative driftU between electrons and protons due to density gradients. The growth rates attain maxima and then decrease as the wave number parallel to the magnetic fieldk _II increases. The peak values of the growth rates, maximised with respect tok _II, are enhanced by the increase in number density, electron temperature and loss cone index, and by the decrease in β_t, the ratio of the proton thermal pressure to magnetic field pressure. The unstable frequencies fall in the range of 5 to 30Ω_p with the growth rate γ ≥Ω_p. In the ring current region betweenL=4 and 5, the instability will generate a strong turbulence in the frequency range between 5–500 Hz which can produce fluctuating electric fields 0. 5–5 mV/m and magnetic field 0.8–80mγ. This instability can also occur on the auroral field lines, which connect to the region of intense earthward plasma flow in the distant magnetotail and produce a broad band electrostatic noise.  相似文献   

青藏高原地区过去2000年来的气候变化   总被引：14，自引：0，他引：14  

杨保 《地球科学进展》2003,18(2):285-291

依据冰芯、树轮、沉积物分析和冰川波动等各单点古气候代用资料,以及重建的综合温度变化曲线,分析了近 2000年青藏高原温度变化的整体性和区域性特征。全青藏高原综合温度曲线显示中世纪暖期（1150-1400年）、小冰期（1400-1900年）以及公元 3～5世纪冷期的存在。青藏高原温度变化具有明显的区域性特征。在 9～11世纪,青藏高原东北部以温暖为特征,而青藏高原南部和西部表现为寒冷。青藏高原南部和西部分别于1150-1400年（此时段在高原东北部表现为弱暖期）和1250-1500年经历了气候变暖。与中国东部文献记录的最新综合研究结果比较,高原东北部与中国东部的温度变化最为一致。而且,许多重大气候事件,如1100-1150年、1500-1550年、1650-1700年和1800-1850年的冷事件在高原和中国东部同时出现,而后 3次冷期与小冰期期间中国西部发生的冰川前进相匹配。  相似文献