检索结果-南通市图书馆

Shadow–highlight feature matching automatic small crater recognition using high-resolution digital orthophoto map from Chang’E Missions

引用

Acta Geochimica 2019年第4期38卷 541-554页

作者： Wei Zuo Chunlai Li Lingjie Yu Zhoubin Zhang Rongwu Wang Xingguo Zeng Yuxuan Liu Yaying Xiong Key Laboratory of Lunar and Deep Space Exploration National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China School of Textile Science and Engineering Xi'an Polytechnic UniversityXi'an 710048China College of Textiles Donghua UniversityShanghai 200051China

This paper introduces a new method of small lunar craters’ automatic identification, using digital orthophoto map(DOM) data. The core of the approach is the fact that the lunar exploration DOM data reveal contrasting highlight and shadow characteristics of small craters under sunlight irradiation. This research effort combines image processing and mathematical modeling. Overall it proposes a new planetary data processing approach, to segment and extract the highlight and shadow regions of small craters,using the image gray frequency(IGF) statistical method.IGF can also be applied to identify the coupling relationships between small craters’ shape and their relative features. This paper presents the highlight and shadow pair matching(HSPM) model which manages to perform highprecision automatic recognition of small lunar craters.Testing was performed using the DOM data of Chang’E-2(CE-2). The results have shown that the proposed method has a high level of successful detection rate. The proposed methodology that uses DOM data can complement the drawbacks of the digital elevation model(DEM) that has a relatively high false detection rate. A hybrid fusion model(FUM) that combines both DOM and DEM data, was carried out to simultaneously identify small, medium, and large-sized craters. It has been proven that the FUM generally shows stronger recognition ability compared to previous approaches and it can be adapted for high precision identification of craters on the whole lunar surface.The results meet the requirements for a reliable and accurate exploration of the Moon and the planets.

关键词： Moon crater recognition Image processing Space exploration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Saliency detection and edge feature matching approach for crater extraction

引用

Journal of Systems Engineering and Electronics 2015年第6期26卷 1291-1300页

作者： An Liu Donghua Zhou Lixin Chen Maoyin Chen Department of Automation Tsinghua University Beijing Institute of Special Electronic-mechanical Technology

craters are salient terrain features on planetary surfaces, and provide useful information about the relative dating of geological unit of planets. In addition, they are ideal landmarks for spacecraft navigation. Due to low contrast and uneven illumination, automatic extraction of craters remains a challenging task. This paper presents a saliency detection method for crater edges and a feature matching algorithm based on edges informa- tion. The craters are extracted through saliency edges detection, edge extraction and selection, feature matching of the same crater edges and robust ellipse fitting. In the edges matching algorithm, a crater feature model is proposed by analyzing the relationship between highlight region edges and shadow region ones. Then, crater edges are paired through the effective matching algorithm. Experiments of real planetary images show that the proposed approach is robust to different lights and topographies, and the detection rate is larger than 90%.

关键词： crater automatic extraction visual saliency featurematching edge detection.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

GEOCHEMICAL FEATURES OF AQUATIC ENVIRONMENT IN crater AND BARRIER LAKES IN NORTHEAST OF CHINA

引用

Chinese Geographical Science 1998年第4期8卷 65-74页

作者：阎百兴

Ｉ．ＩＮＴＲＯＤＵＣＴＩＯＮＭｏｓｔｖｏｌｃａｎｏｅｓａｒｅｄｉｓｔｒｉｂｕｔｅｄｉｎｎｏｒｔｈｅａｓｔｏｆＣｈｉｎａ．Ｔｈｅｖｏｌｃａｎｉｃｅｒｕｐｔｉｏｎｓｃａｎｃｈａｎｇｅｔｈｅｇｅｎｅｒａｌｍｏｒｐｈｏｌｏｇ... 详细信息

Ｉ．ＩＮＴＲＯＤＵＣＴＩＯＮＭｏｓｔｖｏｌｃａｎｏｅｓａｒｅｄｉｓｔｒｉｂｕｔｅｄｉｎｎｏｒｔｈｅａｓｔｏｆＣｈｉｎａ．Ｔｈｅｖｏｌｃａｎｉｃｅｒｕｐｔｉｏｎｓｃａｎｃｈａｎｇｅｔｈｅｇｅｎｅｒａｌｍｏｒｐｈｏｌｏｇｉｃｃｏｎｆｉｇｕｒａｔｉｏｎｏｆ...

关键词： crater lake barrier lake water and sediment geochemical feature northeast of China

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Non-Impact Origin of the Baisha Structure in Hainan Province, China

引用

Journal of Earth Science 2020年第2期31卷 385-392页

作者： Jiang Pu Zhiyong Xiao Long Xiao Cheng Huang Planetary Science Institute School of Earth SciencesChina University of GeosciencesWuhan 430074China Space Science Institute Macao University of Science and TechnologyMacaoChina College of Hydraulic and Ecological Engineering Nanchang Institute of Technology Nanchang 330099China

The Baisha Structure,with a rim-to-rim diameter of^3.7 km,in the center of the Hainan Province,southern China has been considered to be an impact crater.Field investigation and petrological study are presented in this paper to investigate the impact hypothesis for this structure.The^600-m-thick Lower Cretaceous feldspathic quartz sandstones from the Lumuwan Formation are the major outcrops both within and outside of the structure.The amphitheater-shaped rim of the structure is composed of granite porphyries that are intruded in the Lumuwan Formation.Previously interpreted impact breccia and impact melt rocks are actually granite porphyries different cooling rates and weathering status.Rocks from locations that most likely have recorded shock metamorphic signatures are sampled,but petrographic analyses reveal no indications of shock metamorphism.While subtle structural deformation occurs at the contact boundary between the granite porphyries and the feldspathic quartz sandstones,the feldspathic quartz sandstones exhibit uniformed dipping strata across the crater floor and walls.All the evidence suggests that the Baisha Structure was not formed by impact cratering.It most likely has been shaped by a combination of magmatic intrusion and long-term differential erosion.

关键词： impact crater shock metamorphism differential erosion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigating the surface integrity of aluminium based composites machined by EDM

引用

Defence Technology（防务技术） 2019年第3期15卷 338-343页

作者： S.Suresh Kumar M.Uthayakumar S.Thirumalai Kumaran Temel Varol Aykut Canakci Faculty of Mechanical Engineering Kalasalingam University Krishnankoil 626126 India Materials and Metallurgy Department Karadeniz Technical University Turkey

In the present work, the surface characteristics of Electrical Discharge Machined (EDM) Al (6351)eSiC and Al (6351)eSiCeB4C composites are investigated. The composites are prepared by employing the conventional stir casting technique, as it can produce better particle dispersion in the matrix. The detailed experimental study is performed on the composites by varying current (I), duty factor (t), pulse on time (Ton), and the gap voltage (V) in order to analyze the Heat Affected Zone (HAZ) formed in the sub surface and the average crater diameter formed on the machined surface of the composites as an output function. The formation of recast layers, presence of bubbles and the surface texture of the composites at various machining conditions are observed. The results show that the increased Metal Removal Rate (MRR) increases the depth of HAZ and the average crater diameter on the machined area. Further, the addition of B4C particles to the composite produces more surface defect than the AleSiC composite.

关键词： Composites EDM Surface crater HAZ

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dating long thrust systems on Mercury:New clues on the thermal evolution of the planet

引用

Geoscience Frontiers 2020年第3期11卷 855-870页

作者： L.Giacomini M.Massironi V.Galluzzi S.Ferrari P.Palumbo INAF-IAPS Istituto di Astrofisica e Planetologia SpazialiVia Fosso Del Cavaliere 100Rome00133Italy Dipartimento di Geoscienze University of PadovaVia G.Gradenigo 6Padova35131Italy Center of Studies and Activities for Space(CISAS)“G.Colombo” University of PadovaVia Venezia 15Padova35131Italy Dipartimento di Scienze e Tecnologie University of Naples“Parthenope”Centro DirezionaleIsola C4Napoli80143Italy

The global tectonics of Mercury is dominated by contractional features mainly represented by lobate scarps,high relief ridges,and wrinkle ridges.These structures are the expression of thrust faults and are linear or arcuate features widely distributed on Mercury.Locally,these structures are arranged in long systems characterized by a preferential orientation and non-random spatial distribution.In this work we identified five thrust systems,generally longer than 1000 km.They were named after the main structure or crater encompassed by the system as:Thakur,Victoria,Villa Lobos,Al-Hamadhani,and Enterprise.In order to gain clues about their formation,we dated them using the buffered crater counting technique,which can be applied to derive the ages of linear landforms such as faults,ridges and channels.To estimate the absolute age for the end of the thrust system's activity,we applied both Le Feuvre and Wieczorek Production Function and Neukum Production Functions.Moreover,to further confirm the results obtained with the buffered crater counting method,the classic stratigraphic approach has been adopted,in which a faulted and an unfaulted craters were dated for each system.The results gave consistent ages and suggested that the most movements along major structures all over Mercury most likely ended at about 3.6-3.8 Ga.This gives new clues to better understand the tectonics of the planet and,therefore,its thermal evolution.Indeed,the early occurrence of tectonic activity in the planet's history,well before than predicted by the thermophysical models,coupled with the orientation and spatial distribution of the thrust systems,suggests that other processes beside global contraction,like mantle downwelling or tidal despinning,could have contributed to the first stage of the planet's history.

关键词： Mercury Thrust systems crater counting Thermal evolution Planetary geology Structural geology

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analytical model for cratering of semi-infinite metallic targets by long rod penetrators

引用

Science China(Technological Sciences) 2010年第12期53卷 3189-3196页

作者： WEN HeMing, HE Yu & LAN Bin CAS Key Laboratory for Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei 230027, China CAS Key Laboratory for Mechanical Behavior and Design of Materials University of Science and Technology of China Hefei China

Analytical model is presented herein to predict the diameter of crater in semi-infinite metallic targets struck by a long rod penetrator. Based on the observation that two mechanisms such as mushrooming and cavitation are involved in cavity expansion by a long rod penetrator, the model is constructed by using the laws of conservation of mass, momentum, energy, together with the u-v relationship of the newly suggested 1D theory of long rod penetration (see Lan and Wen, Sci China Tech Sci, 2010, 53(5): 1364–1373). It is demonstrated that the model predictions are in good agreement with available experimental data and numerical simulations obtained for the combinations of penetrator and target made of different materials.

关键词： crater diameter long rod penetrator semi-infinite metallic target penetration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Timings of early crustal activity in southern highlands of Mars:Periods of crustal stretching and shortening

引用

Geoscience Frontiers 2019年第3期10卷 1029-1037页

作者： Trishit Ruj Goro Komatsu Jan Hendrik Pasckert James M.Dohm International Research School of Planetary Sciences Università d'Annunzio Department of Earth and Planetary Science School of Science University of Tokyo Institut für Planetologie Westf?lische Wilhelms-Universit?t Foundation for Advancement of International Science

Extensional and compressional structures are globally abundant on Mars. Distribution of these structures and their ages constrain the crustal stress state and tectonic evolution of the planet. Here in this paper, we report on our investigation over the distribution of the tectonic structures and timings of the associated stress fields from the Noachis-Sabaea region. Thereafter, we hypothesize possible origins in relation to the internal/external processes through detailed morphostructural mapping. In doing so, we have extracted the absolute model ages of these linear tectonic structures using crater size-frequency distribution measurements, buffered crater counting in particular. The estimated ages indicate that the tectonic structures are younger than the mega impacts events(especially Hellas) and instead they reveal two dominant phases of interior dynamics prevailing on the southern highlands, firstly the extensional phase terminating around3.8 Ga forming grabens and then compressional phase around 3.5-3.6 Ga producing wrinkle ridges and lobate scarps. These derived absolute model ages of the grabens exhibit the age ca. 100 Ma younger than the previously documented end of the global extensional phase. The following compressional activity corresponds to the peak of global contraction period in Early Hesperian. Therefore, we conclude that the planet wide heat loss mechanism, involving crustal stretching coupled with gravitationally driven relaxation(i.e.,lithospheric mobility) resulted in the extensional structures around Late Noachian(around 3.8 Ga). Lately cooling related global contraction generated compressional stress ensuing shortening of the upper crust of the southern highlands at the Early Hesperian period(around 3.5-3.6 Ga).

关键词： Martian dynamics Southern highlands Extensional tectonics Compressional tectonics Age of structures Buffer crater counting

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Discovery of Shatter Cones at Jueshan Island, Taihu Lake

引用

Chinese Science Bulletin 1994年第14期39卷 1210-1214页

作者：王尔康朱政张海祥曹会 Department of Earth Sciences Nanjing University Nanjing 210008 PRC

Shatter cones are conical fragments of rock characterized by striations that radiate from the apex. In 1905, they were first observed at Steinheim Basin in Germany. In the United States, the well-known occurrence site of shatter cones is Kentland, Indiana. In 1938, when the existence of terrestrial impact crater was still a hypothesis, J. D. Boon had suggested that the structures similar to the Kentland were the products of meteoritic crater. In 1947, when making frequent investigations on Kentland quarry, R. S. Dietz pointed out that the axes of these cones were oriented normal to the bedding, with the apexes pointing toward the top of the bed. Thus, they were formed by giant forces which came from above rather than below. Because except the impact of meteorite, there is not any giant force from space, shatter cones should be 'root' of crater. This argument was proved because of the discovery

关键词： shatter cones crater arc fracturing origin of Taihu lake.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Formation mechanism of the Lidang circular structure in the Guangxi Province

引用

Earth and Planetary Physics 2019年第4期3卷 298-304页

作者： Pan Yan ZhiYong Xiao YiZhen Ma YiChen Wang Jiang Pu Planetary Science Institute School of Earth Sciences China University of Geosciences (Wuhan) Wuhan 430074 China 2State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and Technology Macao 999078 China Chinese Academy of Sciences Center for Excellence in Comparative Planetology Beijing 100864 China

The Lidang circular structure in the center of the Guangxi Province is about 8 km in diameter. This structure appears as an abnormal shallow depression that has disturbed the rather harmonic regional joint systems. Its unique occurrence in the whole region, the circular morphology, negative topography, and the spatial distribution of interior and exterior strata are all consistent with those of impact craters that are formed by asteroidal or cometary collision. To test the impact hypothesis, we carried out both field investigation and remote sensing study of this structure. Regional geological history suggests that if the impact hypothesis were correct, the impact event should have occurred at or after the Early Permian. Field investigation found that the strata inside and outside the crater are dominated by parallel stacks of Lower and Upper Permian limestone that have various thicknesses and different mud contents. The layers of limestone within and outside the circular structure have identical attitudes;no structural disturbances were visible in the outcrops. Field investigations provide conclusive evidence against the impact cratering hypothesis. A high-resolution digital elevation model shows that the spatial distribution of rounded mountains within the structure is controlled by faint but continual extension of joints, suggesting that the crater interior has gone through a much higher degree of erosion. Therefore, regional joints that had once existed within the crater are preserved less well than exterior terrains, forming the abruptly disrupted circular depression. Differential erosion, as the possible formation mechanism of the Lidang structure, is consistent with the different mud contents found between the interior and exterior limestone. The circular outline of this structure may correspond to the shape of the original deposition basin. In conclusion, the Lidang circular structure is a polje formed by karstification, not an astrobleme.

关键词： impact crater impact cratering geomorphology karst Guangxi

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：