高速屏蔽层下广角地震波场分析及成像方法

在高速玄武岩屏蔽区进行勘探存在一定困难,本文以我国南 方典型靶区为例,提出了解决问题的方法. 首先从理论上探讨了广角地震信号存在的条件以 及在应用过程中所面临的问题. 利用正演理论模型分析了广角地震信号的运动学特征以及噪 声对广角反射的影响. 利用物理模型对广角地震的动力学特征、波场特征及动校拉伸现象进 行了分析. 在上述基础上,对广角地震数据作了精细处理,完成了玄武岩下的地震成像.     

Phytogeographic and Syntaxonomic Diversity of High Mountain Vegetation in Dinaric Alps (Western Balkan,SE Europe)

The high alpine and subalpine vegetation of Dinaric Alps is very diverse.These are conditional on genuine patterns of development of the geological substrate,climate,soil and terrain on the mountain world,which are interconnected and spatially,and ecologically away.Also,today high mountain vegetation is extremely important indicator of global changes.In this area are many refugia of glacial biodiversity.Very illustrative example for understanding the specific forms of ecological diversity is high alpine veg...     

芒果稳产高产综合技术研究

为了探讨芒果丰产技术,消除生产中的大小年现象,通过使用合理修剪、施肥和病虫防治,隔年施一次15％多效唑（PP333）15～30g／株,于10月份土施并保湿2周,摘除2月上旬前抽出的花芽,使花期推迟至3月中旬以后等技术,试验的4．4km2果园连续4年丰收,平均年产29169．5kg／km2。     

锦屏水电站解放沟反倾高边坡变形机制的探讨

通过对锦屏水电站某一反倾高边坡的野外调查、室内测试实验及数值模拟计算分析 ,对其变形机制有了进一步的认识。对以往的结论重新进行论证 ,用证据说明问题 ,最终得出新的研究成果。本文认为解放沟左岸深层变形是由河谷快速下切过程中边坡发生深部卸荷松弛和倾内层状体斜坡的深部岩层弯曲倾倒共同作用所引起     

金字塔沙丘形成的动力条件分析

金字塔沙丘(或星状沙丘)形成的动力条件主要有三个方面:一是在非沙质床面的气流场辐合区,一般具有三个以上近似均布的主风向,各主风向的风力强度、出现频率及持续时间不尽相同,但年总输沙能力较为接近,而且月输沙能力具有明显的季节变化;二是不太充裕的沙源和高浓度不饱和风沙流;三是不同尺度地形条件的动力作用,和沙漠与戈壁下垫面的热力影响。在沙质床面,往往由于高浓度饱和或过饱和风沙流的作用,导致新月形沙丘或新月形沙丘链的变态,或重新组合成金字塔状的沙丘形态,但不可能发育为典型的金字塔沙丘。     

Accuracy assessment of airborne photogrammetrically derived high-resolution digital elevation models in a high mountain environment

High-resolution digital elevation models (DEMs) generated by airborne remote sensing are frequently used to analyze landform structures (monotemporal) and geomorphological processes (multitemporal) in remote areas or areas of extreme terrain. In order to assess and quantify such structures and processes it is necessary to know the absolute accuracy of the available DEMs. This study assesses the absolute vertical accuracy of DEMs generated by the High Resolution Stereo Camera-Airborne (HRSC-A), the Leica Airborne Digital Sensors 40/80 (ADS40 and ADS80) and the analogue camera system RC30. The study area is located in the Turtmann valley, Valais, Switzerland, a glacially and periglacially formed hanging valley stretching from 2400 m to 3300 m a.s.l. The photogrammetrically derived DEMs are evaluated against geodetic field measurements and an airborne laser scan (ALS). Traditional and robust global and local accuracy measurements are used to describe the vertical quality of the DEMs, which show a non Gaussian distribution of errors. The results show that all four sensor systems produce DEMs with similar accuracy despite their different setups and generations. The ADS40 and ADS80 (both with a ground sampling distance of 0.50 m) generate the most accurate DEMs in complex high mountain areas with a RMSE of 0.8 m and NMAD of 0.6 m They also show the highest accuracy relating to flying height (0.14‰). The pushbroom scanning system HRSC-A produces a RMSE of 1.03 m and a NMAD of 0.83 m (0.21‰ accuracy of the flying height and 10 times the ground sampling distance). The analogue camera system RC30 produces DEMs with a vertical accuracy of 1.30 m RMSE and 0.83 m NMAD (0.17‰ accuracy of the flying height and two times the ground sampling distance). It is also shown that the performance of the DEMs strongly depends on the inclination of the terrain. The RMSE of areas up to an inclination <40° is better than 1 m. In more inclined areas the error and outlier occurrence increase for all DEMs. This study shows the level of detail to which airborne stereoscopically derived DEMs can reliably be used in high mountain environments. All four sensor systems perform similarly in flat terrain.     

南阿尔金尤努斯萨依花岗质高压麻粒岩的发现及其地质意义

南阿尔金尤努斯萨依地区首次发现一套高压麻粒岩相特征矿物组合的含蓝晶石石榴子石的花岗质片麻岩,其矿物组合为Grt+Ky+Per(+Ksp)+Ru+Q。依据矿物内部一致性热力学数据,基于THERMOCALC 3. 40程序平台,计算出P-T视剖面图,并结合矿物等值线、矿物组合稳定域及三元长石温度计等,确定其早期变质温压条件为T=970～1010℃,P=23. 2～25. 3kbar,达到了榴辉岩相变质条件。同时,根据岩相学观察获得的矿物共生组合与矿物变质显微结构以及P-T视剖面图,可识别出该岩石在早期变质之后还经历了以矿物组合Grt+Ky+Per(+Ksp)+Pl+Ru+Q为代表的麻粒岩相、以及Grt+Ky+Ksp+Pl+Bi+Ru+Ilm+Q为代表的麻粒岩-高角闪岩相和以Ky+Ksp+Pl+Q+Bi+Mu+Ru+Ilm为代表的角闪岩相三期退变质作用,它们共同构成了一个顺时针型降温降压的退变质P-T演化轨迹,指示出与大陆俯冲-深俯冲相关的高压变质事件和俯冲碰撞后的折返事件。利用LA-ICP-MS进行的锆石原位微区U-Pb定年和微量元素分析表明,该高压岩石峰期变质年龄497. 8±2. 7Ma,与南阿尔金地区已发现的高压-超高压岩石的峰期变质时代完全一致,表明它们应属同一变质岩带;其原岩形成时代为900. 2±4. 1Ma,与南阿尔金已报道的正变质的高压-超高压岩石原岩的形成时代基本一致,指示它们可能具有相同的原岩属性。这套花岗质高压麻粒岩的确定为进一步约束南阿尔金早古生代高压-超高压变质岩带的时空分布规律提供了新的限定。     

2005年7月清江流域一次连续暴雨的中尺度分析

利用气象卫星、多普勒雷达及常规气象资料,对2005年7月8～10日清江流域连续暴雨过程进行综合分析。结果表明:(1)高低空急流的优势配置、高空急流右侧强辐散场的存在,副热带高压稳定于我国东南沿海,为此次暴雨提供了有利的大尺度环境背景;(2)雨团滞留和经过区域正是暴雨发生区域;(3)低层垂直风切变可使回波加强而产生强降水;(4)雷达回波中“逆风区”对于暴雨识别及暴雨落区预报具有很好的指示性。     

非饱和黏性土抗剪强度的温度效应试验研究

为了系统地了解温度对黏性土工程性质的影响,本文采用南京地区三种不同矿物成分的黏性土,制成不同含水量和干密度的试样,在5～45℃条件下,开展了抗剪强度试验,获得了三种土的非饱和重塑试样的抗剪强度与温度的关系.试验结果表明:黏性土的黏聚力随温度升高呈线性变化;亲水矿物含量较高的黏性土抗剪强度对温度变化较敏感,黏聚力随着温度...     

我国西北夏季降水异常与太平洋海温季节演变的关系

本文利用交叉相关场的EOF分解考查了我国西北夏季降水与太平洋季节海温遥相关的结构。然后分别就我国西北夏季降水偏多年与偏少年对应的各季海温进行了自然正交（EOF）和复自然正交（CEOF）的合成分析,得到了我国西北夏季降水多、寡年对太平洋海温空间分布异常特征的季节演变。最后利用非参数跃变检验诊断了我国西北降水的跃变,并讨论了与太平洋海温跃变的联系。