安徽铜陵朝山金矿床地质特征及成因研究

朝山金矿床位于安徽铜陵狮子山矿田内,与成矿相关的侵入岩体为白芒山辉石闪长岩.文章通过对朝山金矿床矿石矿物含金性和方解石-黄铁矿脉内方解石及碳酸盐岩全岩碳、氧同位素研究,探讨朝山金矿床中金的赋存状态和矿床成因.矿石矿物电子探针测试表明,朝山金矿床矿石矿物中毒砂、磁黄铁矿和黄铁矿含金性较好.C,O同位素测试表明,方解石-黄铁矿脉内方解石中的δ(13CPDB)=-2.57×10-3～-4.87×10-3,δ(18OPDB)=-15.68×10-3～-17.33×10-3,δ(18OSMOW)=13.05×10-3～14.74×10-3,碳酸盐岩全岩中δ(13CPDB)=0.88×10-3～1.97×10-3,δ(18OPDB)=-7.55×10-3～-9.12×10-3,δ(18OSMOW)=21.46×10-3～23.08×10-3,说明朝山金矿床的成矿物质主要来源于岩浆或深部地壳流体.伴随着成矿作用的进行,朝山金矿床经历了从高温到低温热液蚀变过程,同时混入了地壳上部沉积物.     

基于声呐图像的水雷目标检测技术简述

针对水雷目标探测识别困难这一现实问题,分析了水雷及其声呐图像的主要特点,介绍了基于统计特征、形态学、最大熵、分形和聚类等传统水雷识别方法和基于深度学习技术的水雷目标检测算法,以期为后续算法研发提供技术参考。     

Water Footprint Assessment for Coal-to-Gas in China

Natural Resources Research - To increase its domestic gas production and achieve cleaner end-use utilization of its coal resources, China is actively promoting its coal-to-gas (CTG) industry....     

Underwater Object Recognition Based on Deep Encoding-Decoding Network

Ocean underwater exploration is a part of oceanography that investigates the physical and biological conditions for scientific and commercial purposes. And video technology plays an important role and is extensively applied for underwater environment observation. Different from the conventional methods, video technology explores the underwater ecosystem continuously and non-invasively. However, due to the scattering and attenuation of light transport in the water, complex noise distribution and lowlight condition cause challenges for underwater video applications including object detection and recognition. In this paper, we propose a new deep encoding-decoding convolutional architecture for underwater object recognition. It uses the deep encoding-decoding network for extracting the discriminative features from the noisy low-light underwater images. To create the deconvolutional layers for classification, we apply the deconvolution kernel with a matched feature map, instead of full connection, to solve the problem of dimension disaster and low accuracy. Moreover, we introduce data augmentation and transfer learning technologies to solve the problem of data starvation. For experiments, we investigated the public datasets with our proposed method and the state-of-the-art methods. The results show that our work achieves significant accuracy. This work provides new underwater technologies applied for ocean exploration.     

沙漠非传统节事旅游的影响因素及驱动机制——以阿拉善沙漠e族英雄会为例

沙漠非传统节事旅游正在兴起,并对地方经济、文化产生深刻影响。以阿拉善沙漠e族英雄会为例,结合问卷调查和地理探测器,探究了沙漠非传统节事游客出游的影响因素及驱动机制,并为沙漠非传统节事旅游的发展提出建议。结果表明：（1）亚文化群体是沙漠非传统节事旅游的主导者,具有亚文化性、团体性、爆发性和跨地域性特征。（2）影响沙漠非传统节事旅游的推力因素依次为社交和休闲 > 附带出游 > 求新求异 > 寻求亚文化归属;拉力因素依次为亚文化主题活动 > 商品展销 > 英雄会文化 > 地域文化,推、拉力驱动因子之间交互作用并呈双因子非线性增强,形成“T （推力）激发旅游需要—L （拉力）催生旅游动机—T、L共同促成旅游行为”的驱动过程。（3）沙漠非传统节事旅游流的产生一般要在推力和拉力的相互作用下经历旅游需要—旅游动机—旅游需求—旅游决策—旅游行为5个阶段。     

船舶磁防护与电场防护耦合性分析

根据船舶电磁场综合防护需求,对磁场防护和电场防护的耦合性进行了研究,总结了 11 种电磁场产生来源,分析了不同电磁场源产生的磁场和电场的耦合关系。 基于磁场和电场耦合性分析数学模型, 仿真分析了磁场和电场耦合特性,指出了需结合多种控制措施实现船舶磁场和电场的综合防护。     

Diagenetic history of tight sandstones and gas entrapment in the Yulin Gas Field in the central area of the Ordos Basin,China

The Ordos Basin is a large cratonic basin with an area of 250,000 km² in central China. Upper Paleozoic coals and shales serve as gas source rocks with peak generation and migration at the end of the early Cretaceous. Recent exploration has verified the huge gas potential in the “basin-centered gas accumulation system” (BCGAS). However, the mechanism for the gas accumulation is controversial. With an integrated approach of thin-section petrography, ultra-violet fluorescence microscopy, fluid inclusion microthermometry, Raman microspectrometry, scanning electron microscopy, and X-ray diffractometry, we identified diagenetic trapping and evaluated the diagenetic history of sandstone reservoirs in the Yulin Gas Field in the central area, where structural, stratigraphic and/or sedimentary lithologic traps have not been found. It was revealed that three phases of diagenesis and hydrocarbon charging occurred, respectively, in the late Triassic, late Jurassic and at the end of the early Cretaceous. In the first two phases, acidic water entered the reservoir and caused dissolution and cementation, resulting in porosity increase. However, further subsidence and diagenesis, including compaction and cementation, markedly reduced the pore space. At the end of the early Cretaceous, the bulk of the gas migrated into the tight reservoirs, and the BCGAS trap was formed. In the updip portion of this system, cementation continued to occur due to low gas saturation and has provided effective seals to retain gas for a longer period of time than water block in the BCGAS. The mechanism for the gas entrapment was changed from water block by capillary pressure in the BCGAS to diagenetic sealing. The diagenetic seals in the updip portion of the sand body were formed after gas charging, which indicates that there is a large hydrocarbon exploration potential at the basin-centered area.     

广西江州地区地质构造影像特征

文章研究了航卫片对江州地区地质构造特征的解译.说明通过解译,能获得较好的地质构造信息,并综合这些特征,编绘出航卫片地质构造解译图.     

Ambiguity resolution in precise point positioning with hourly data

Precise point positioning (PPP) has become a powerful tool for the scientific analysis of Global Positioning System (GPS) measurements. Until recently, ambiguity resolution at a single station in PPP has been considered difficult, due to the receiver- and satellite-dependent uncalibrated hardware delays (UHD). However, recent studies show that if these UHD can be determined accurately in advance within a network of stations, then ambiguity resolution at a single station becomes possible. In this study, the method proposed by Ge et al. J Geod 82(7):389–399, 2007 is adopted with a refinement in which only one single-difference narrow-lane UHD between a pair of satellites is determined within each full pass over a regional network. This study uses the EUREF (European Reference Frame) Permanent Network (EPN) to determine the UHD from Day 245 to 251 in 2007. Then 12 International GNSS Service stations inside the EPN and 15 outside the EPN are used to conduct ambiguity resolution in hourly PPP. It is found that the mean positioning accuracy in all hourly solutions for the stations inside the EPN is improved from (3.8, 1.5, 2.8) centimeters to (0.5, 0.5, 1.4) centimeters for the East, North and Up components, respectively. For the stations outside the EPN, some of which are over 2,000 km away from the nearest EPN stations, the mean positioning accuracy in the East, North and Up directions still achieves (0.6, 0.6, 2.0) centimeters, respectively, when the EPN-based UHD are applied to these stations. These results demonstrate that ambiguity resolution at a single station can significantly improve the positioning accuracy in hourly PPP. Particularly, UHD can be even applied to a station which is up to thousands of kilometers from the UHD-determination network, potentially showing a great advantage over current network-based GPS augmentation systems. Therefore, it is feasible and beneficial for the operators of GPS regional networks and providers of PPP-based online services to provide these UHD estimates as an additional product.