Fault Characteristics in Longmen Mountain Thrust Belt,Western Sichuan Foreland Basin,China

Through field geological survey,the authors found that abundant thrust faults developed in the Longmen (龙门) Mountain thrust belt.These faults can be divided into thrust faults and strike-slip faults according to their formation mechanisms and characteristics.Furthermore,these faults can be graded into primary fault,secondary fault,third-level fault,and fourth-level fault according to their scale and role in the tectonic evolution of Longmen Mountain thrust belt.Each thrust fault is composed of several secondary faults,such as Qingchuan (青川)-Maowen (茂汶) fault zone is composed of Qiaozhuang (乔庄) fault,Qingxi (青溪) fault,Maowen fault,Ganyanggou (赶羊沟) fault,etc..The Longmen Mountain thrust belt experienced early Indosinian movement,Anxian (安县) movement,Yanshan (燕山)movement,and Himalayan movement,and the faults formed gradually from north to south.     

长江口深水航道治理工程实施后南北槽分汊段河床演变

利用1998-2006年的水深测图和南北槽分流、分沙比测量资料,研究了长江口深水航道治理工程实施后南、北槽分流比的变化过程、原因及其与分汊口河床冲淤演变的关系。结果表明,随着长江口深水航道治理工程的实施,北槽落潮分流比总体呈减小的趋势,南槽落潮分流比呈增加的趋势。伴随着南、北槽落潮分流比的南增、北减,南槽进口段(长约18 km)的主槽发生了冲刷,北槽进口段(长约12 km)的主槽发生了淤积,南、北槽进口段河槽总过水断面面积呈下降趋势。北槽落潮分流比与北槽河槽总容积、南北槽落潮分流比与各自进口段的河槽断面平均水深之间均具有较好的相关性,据此,预测了未来南、北槽的落潮分流比和进口段河槽冲淤的平衡量值。     

SAR图像点目标检测新方法

分析了2L-IHP目标检测算法,提出了一种基于幅度和相位信息的SAR图像目标检测方法,实现了SAR图像中人工目标的有效检测.     

Regional yield estimation for winter wheat with MODIS-NDVI data in Shandong, China

The significance of crop yield estimation is well known in agricultural management and policy development at regional and national levels. The primary objective of this study was to test the suitability of the method, depending on predicted crop production, to estimate crop yield with a MODIS-NDVI-based model on a regional scale. In this paper, MODIS-NDVI data, with a 250 m resolution, was used to estimate the winter wheat (Triticum aestivum L.) yield in one of the main winter-wheat-growing regions. Our study region is located in Jining, Shandong Province. In order to improve the quality of remote sensing data and the accuracy of yield prediction, especially to eliminate the cloud-contaminated data and abnormal data in the MODIS-NDVI series, the Savitzky–Golay filter was applied to smooth the 10-day NDVI data. The spatial accumulation of NDVI at the county level was used to test its relationship with winter wheat production in the study area. A linear regressive relationship between the spatial accumulation of NDVI and the production of winter wheat was established using a stepwise regression method. The average yield was derived from predicted production divided by the growing acreage of winter wheat on a county level. Finally, the results were validated by the ground survey data, and the errors were compared with the errors of agro-climate models. The results showed that the relative errors of the predicted yield using MODIS-NDVI are between −4.62% and 5.40% and that whole RMSE was 214.16 kg ha⁻¹ lower than the RMSE (233.35 kg ha⁻¹) of agro-climate models in this study region. A good predicted yield data of winter wheat could be got about 40 days ahead of harvest time, i.e. at the booting-heading stage of winter wheat. The method suggested in this paper was good for predicting regional winter wheat production and yield estimation.     

河南镇平秋树湾矿区铜、钼矿床地质特征及深部找矿潜力分析

秋树湾矿区是一座中型规模的铜、钼矿床。在水平方向上矿区具北铜南钼的分布特征,即北山铜矿床和南山钼矿床;从垂向上看,北山铜矿床深部赋存有规模较大的钼矿体,并具垂直分带现象,即上铜下钼。这主要是矿区成矿后,构造活动使南山赋矿区向上逆冲,使其上部的铜矿体被剥蚀,而北山赋矿区上部的矿体则保存了下来。因此,研究认为,在北山铜矿区的下部及南山钼矿区中深部寻找隐伏钼矿床具有较大潜力。     

基于多基站网络的VRS差分改正信息的方法分析

基于虚拟参考站VRS(Virtual Reference Stations)的GPS测量技术是近几年应用在网络RTK中的热门技术,文中首先介绍VRS的基本原理,然后利用站际星际二次差分技术,推导虚拟观测值,最后讨论研究虚拟参考站的双差改正数的内插算法。     

三峡库区消落区土壤磷释放的环境影响因子

以三峡库区消落区万州段为试验基地,选取释磷能力较强的紫色冲积土,根据三峡水库消落带的"干湿交替"空间和时间特征,进行万州断面土壤磷释放的影响因子的实验室模拟试验和万州江面淹没的对照试验。研究发现,随着淹水时间的变化,各种形态的磷在前5~10d各形态磷变化有相当的差异,随后变化趋势趋于稳定。TP有降低的趋势,土壤磷有一定的释放。野外研究表明Olsen-P在淹水10周左右到达最大值,以后缓慢降低。淹水时土壤Olsen-P增加,干燥后降低。多次淹水时每次淹水后土壤的有效磷水平都略有增加,落干后相较上次落干后有效磷水平降低,最后一次淹水后相较与初始时Olsen-P水平低16.7%。随着淹水深度增加,土壤的Olsen-P水平在淹水时由淹水前20.53mg/kg提高到43.23mg/kg,增加110.6%。当上覆水磷浓度较低时(<2mg/L),磷吸附到达平衡的时间较短,约需要6周。当上覆水磷浓度较高(>2mg/L)时,磷吸附到达平衡的时间较长。微生物活动对淹水土壤的磷释放有一定影响,有微生物时磷的释放高于无微生物者0.048mg/L。种植植物的土壤在淹水后Olsen-P含量大于土壤直接淹没时的释放量,种植狗牙根(Cynodondactylon)和野地瓜藤(Ficustikoua)的土壤中Olsen-P分别较未种植物土壤释放量高出21.5%和12.7%。     

盘县马依东二井田构造特征及成因分析

利用井田勘探资料及野外地质资料,对井田构造基本形态、断层发育特征及其分布规律进行分析,总结出该井田的构造模式、构造成因、构造组合特征及其演化规律。研究认为井田的构造格局是多期构造运动综合作用、相互叠加的结果。井田构造形态为一略有起伏的平缓单斜,区内NE向的高角度正断层,多属张扭性,EW向构造早于NE向构造,构造复合部位较复杂,其余区段较简单;伸展构造是井田构造的主体样式,这一结论对下一步继续勘探及煤矿开采具有指导意义。     

光谱快速预选筛分算法研究

利用一组标准正交化的参考向量得到一个可能匹配区域,排除了绝大部分不可能匹配的样本,从而大大提高光谱预选筛分的速度;同时介绍了一种平衡速度与精度的编码替代算法.实验证明:压缩影像的目视效果较好,未产生边缘模糊及条带现象;采用自动目标生成方法(ATGP)从样本集中提取端元并进行光谱角度制图,其效果令人满意.