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121.
冀中饶阳凹陷大王庄地区古近系属断陷湖盆演化阶段,分为断陷分割期、断陷扩张期和断陷萎缩期3个时期,发育辫状河三角洲、滨浅湖和曲流河3类沉积体系。在等时地层格架内,分析了该地区沉积演化特征和储盖组合的分布及时空展布规律,指出该区古近系主要发育沙三段、沙二段、沙一段和东营组4套储盖组合,其中沙一段储盖组合为最有利的含油储盖组合。 相似文献
122.
Chao LIU Shu YANG Di DI Yuanjian YANG Chen ZHOU Xiuqing HU Byung-Ju SOHN 《大气科学进展》2022,39(12):1994-2007
Cloud Masking is one of the most essential products for satellite remote sensing and downstream applications. This study develops machine learning-based (ML-based) cloud detection algorithms using spectral observations for the Advanced Himawari Imager (AHI) onboard the Himawari-8 geostationary satellite. Collocated active observations from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) are used to provide reference labels for model development and validation. We introduce both daytime and nighttime algorithms that differ according to whether solar band observations are included, and the artificial neural network (ANN) and random forest (RF) techniques are adopted for comparison. To eliminate the influences of surface conditions on cloud detection, we introduce three models with different treatments of the surface. Instead of developing independent ML-based algorithms, we add surface variables in a binary way that enhances the ML-based algorithm accuracy by ~5%. Validated against CALIOP observations, we find that our daytime RF-based algorithm outperforms the AHI operational algorithm by improving the accuracy of cloudy pixel detection by ~5%, while at the same time, reducing misjudgment by ~3%. The nighttime model with only infrared observations is also slightly better than the AHI operational product but may tend to overestimate cloudy pixels. Overall, our ML-based algorithms can serve as a reliable method to provide cloud mask results for both daytime and nighttime AHI observations. We furthermore suggest treating the surface with a set of independent variables for future ML-based algorithm development. 相似文献
123.
通过对云南玉龙雪山丽江冷杉年轮晚材纤维素氧同位素 (δ18O) 的分析,建立了1902-2004时段年分辨率的树轮δ18O序列。将所得序列与相邻的丽江市气象站记录的气候资料对比,分析了树轮δ18O对气候要素的响应。结果表明,丽江冷杉年轮晚材中的δ18O与其生长季气候因子密切相关。主要与季风期 (8-10月) 的降水和相对湿度、6-10月总云量、5-6月平均温度显著相关,尤其和总云量相关性最高 (r = -0.45,P = 0.01)。同时,树轮δ18O年际变化与南亚季风指数、东亚夏季风指数呈反相关关系,并与1-5月南方涛动指数负相关显著,在一定程度上反映了大尺度的大气环流影响。 相似文献
124.
125.
根据GEO卫星的特点,给出了电离层扰动序列的提取方法以及扰动振幅、周期的获取方法,并根据实测的2012-04-16~2012-04-18的观测数据,对探测到的电离层扰动进行了初步分析。实验结果显示,1号GEO卫星在2014-04-17T12:30左右探测到扰动,5号GEO卫星和4号GEO卫星分别在2012-04-17T18:50~2012-04-17T20:45和2012-14-18T06:00~2012-04-18T07:23探测到扰动,探测的电离层扰动发生时间及扰动的振幅、周期等传播特性与前人研究基本一致,而且提取的扰动序列不包含多谱勒效应的影响。 相似文献
126.
Generating GPS satellite fractional cycle bias for ambiguity-fixed precise point positioning 总被引:1,自引:0,他引:1
With the development of precise point positioning (PPP), the School of Geodesy and Geomatics (SGG) at Wuhan University is now routinely producing GPS satellite fractional cycle bias (FCB) products with open access for worldwide PPP users to conduct ambiguity-fixed PPP solution. We provide a brief theoretical background of PPP and present the strategies and models to compute the FCB products. The practical realization of the two-step (wide-lane and narrow-lane) FCB estimation scheme is described in detail. With GPS measurements taken in various situations, i.e., static, dynamic, and on low earth orbit (LEO) satellites, the quality of FCB estimation and the effectiveness of PPP ambiguity resolution (AR) are evaluated. The comparison with CNES FCBs indicated that our FCBs had a good consistency with the CNES ones. For wide-lane FCB, almost all the differences of the two products were within ±0.05 cycles. For narrow-lane FCB, 87.8 % of the differences were located between ±0.05 cycles, and 97.4 % of them were located between ±0.075 cycles. The experimental results showed that, compared with conventional ambiguity-float PPP, the averaged position RMS of static PPP can be improved from (3.6, 1.4, 3.6) to (2.0, 1.0, 2.7) centimeters for ambiguity-fixed PPP. The average accuracy improvement in the east, north, and up components reached 44.4, 28.6, and 25.0 %, respectively. A kinematic, ambiguity-fixed PPP test with observation of 80 min achieved a position accuracy of better than 5 cm at the one-sigma level in all three coordinate components. Compared with the results of ambiguity-float, kinematic PPP, the positioning biases of ambiguity-fixed PPP were improved by about 78.2, 20.8, and 65.1 % in east, north, and up. The RMS of LEO PPP test was improved by about 23.0, 37.0, and 43.0 % for GRACE-A and GRACE-B in radial, tangential, and normal directions when AR was applied to the same data set. These results demonstrated that the SGG FCB products can be produced with high quality for users anywhere around the world to carry out ambiguity-fixed PPP solutions. 相似文献
127.
为了研究甘肃北山大山头含铜镍硫化物基性、超基性岩的成矿潜力,通过野外调查和室内综合对比研究,取得如下 认识及成果:(1)大山头岩体侵位于前寒武系中深变质碎屑岩与片麻状花岗岩中,为多期次侵位的杂岩体,早期以中细粒辉 长岩岩基为主,晚期为橄榄苏长辉长岩-二辉橄榄岩相基性-超基性岩,岩体分异明显,橄榄二辉岩全岩铜镍矿化(Cu 含量 0.08%~0.46%,Ni 含量 0.2%~0.37% ):(2)岩体常量和微量元素具岛弧基性超基性岩浆特征(例如岩体亏损高场强元素 Nb, Ta,Ti,Hf 及 Y 和 P,富集大离子亲石元素 Ba,Rb,Th,U,K 及 La 等);(3)磁法异常与岩体地表矿化一致,电法结果显示 岩体深部矿化更好(最大磁场强度值 600nT,视极化率(ηs)显示最大值可达 7.5%~12.1%);(4)岩体岩石地球化学特征与金川、 喀拉通克、红旗岭等相似,与甘肃黑山一致。因此,大山头有望成为储量规模不亚于甘肃黑山的铜镍硫化物矿床。 相似文献
128.
王晓鸿 《地质灾害与环境保护》1999,10(1):72-78
从目前施工面临的问题出发,利用人工智能工具CLIPS语言建立一个简单的基于知识的基于基坑施工监控器,主要用于解决监测数据的自动查错、变形趋势预测、变形自动报警,以及具有自学习的施工应急措施。 相似文献
129.
HUANG Junping YANG Zhanlong CHEN Qilin DI Jun BAI Yunlai LI Zhiyong and HUANG Chenggang 《《地质学报》英文版》2015,89(Z1):41-44
<正>1 Introduction Qinshui Basin is the major coal bearing basin in China.And the main exploration target layer is CarboniferousPermian.In recent years,not only in the coal-bed methane has made great progress,and also in the tight gas.Besides,shale gas in the Carboniferous-Permian has showed a good exploration prospect.Although Carboniferous- 相似文献
130.
采用IR光谱和质谱技术分析了海南福基田幔源巨晶和包体中辉石的结构羟基红外光谱和氢氧同位素。测试的所有巨晶普通辉石和包体中透辉石及顽火辉石均含结构OH,对比印证了国内外同类矿物的红外光谱特征。结构水质量分数分别是:普通辉石87×10-6~389×10-6;透辉石127×10-6~273×10-6;顽火辉石69×10-6~207×10-6。包体中结构水质量分数为1 811×10-6~5 377×10-6,平均为3 133×10-6。包体中辉石的氢氧同位素特征如下:透辉石的δ(D)为-123.17‰,顽火辉石的δ(D)为-132.04‰;透辉石的δ(18O)为5.96‰,顽火辉石的δ(18O)为5.60‰。实验和对比表明,辉石是海南福基田上地幔重要的水储库,包体未受地壳成分污染,继承和保持了上地幔富水贫氘的特征。上述结果为该地区上地幔研究提供了结构水和氢氧同位素的基础资料。 相似文献