检索结果-南通市图书馆

Applied Geophysics 2020年第5期17卷 709-718,901页

作者： Wang Hong-Hua Gong Jun-bo Zhang zhi Xiong Bin Lv Yu-zeng Feng De-shan Dai Qian-wei College of earth sciences Guilin University of TechnologyGuilin 541004China Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration Guilin 541004China School of Geosciences and Info-Physics Central South UniversityChangsha 410083China.

The reverse time migration(RTM)of ground penetrating radar(GPR)is usually implemented in its two-dimensional(2D)form,due to huge computational ***,2D RTM algorithm is difficult to focus the scattering signal and produce a high precision subsurface image when the object is buried in a complicated subsurface *** better handle the multi-off set GPR data,we propose a three-dimensional(3.)prestack RTM *** high-order fi nite diff erence time domian(FDTD)method,with the accuracy of eighth-order in space and second-order in time,is applied to simulate the forward and backward extrapolation electromagnetic fi *** addition,we use the normalized correlation imaging condition to obtain pre-stack RTM result and the Laplace fi lter to suppress the low frequency noise generated during the correlation *** numerical test of 3. simulated GPR data demonstrated that 3. RTM image shows excellent coincidence with the true *** with 2D RTM image,the 3. RTM image can more clearly and accurately refl ect the 3. spatial distribution of the target,and the resolution of the imaging results is far ***,the application of observed GPR data further validates the eff ectiveness of the proposed 3. GPR RTM algorithm,and its fi nal image can more reliably guide the subsequent interpretation.

关键词： Ground Penetrating Radar(GPR) 3. Reverse Time Migration(RTM) Finite Diff erence Time Domain(FDTD) Normalized correlation imaging condition

Rock thin-section analysis and identification based on artificial intelligent technique

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum science 2022年第4期19卷 1605-1621页

作者： He Liua Yi-Li Ren Xin Li Yan-Xu Hu Jian-Ping Wu Bin Li Lu Luo zhi Tao Xi Liu Jia Liang Yun-Ying Zhang Xiao-Yu An Wen-Kai Fang Petrochina Research Institute of Petroleum Exploration&Development Beijing100083China Research Institute of Petroleum Exploration and Development PetroChina Huabei Oilfield CompanyHebei Renqiu062552China

Rock thin-section identification is an indispensable geological exploration tool for understanding and recognizing the composition of the *** is also an important evaluation method for oil and gas exploration and *** can be used to identify the petrological characteristics of reservoirs,determine the type of diagenesis,and distinguish the characteristics of reservoir space and pore *** is necessary to understand the physical properties and sedimentary environment of the reservoir,obtain the relevant parameters of the reservoir,formulate the oil and gas development plan,and reserve *** traditional thin-section identification method has a history of more than one hundred years,which mainly depends on the geological experts'visual observation with the optical microscope,and is bothered by the problems of strong subjectivity,high dependence on experience,heavy workload,long identification cycle,and incapability to achieve complete and accurate *** this paper,the models of particle segmentation,mineralogy identification,and pore type intelligent identification are constructed by using deep learning,computer vision,and other technologies,and the intelligent thinsection identification is *** paper overcomes the problem of multi-target recognition in the image sequence,constructs a fine-grained classification network under the multi-mode and multi-light source,and proposes a modeling scheme of data annotation while building models,forming a scientific,quantitative and efficient slice identification *** experimental results and practical application results show that the thin-section intelligent identification technology proposed in this paper does not only greatly improves the identification efficiency,but also realizes the intuitive,accurate and quantitative identification results,which is a subversive innovation and change to the traditional thin-section identification practice.

关键词： Thin-section identification Artificial intelligence Deep learning Computer vision Sedimentary reservoir

Geoeffectiveness of the coronal mass ejections associated with solar proton events

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2016年第1期16卷 117-128页

作者： Gui-Ming Le Chuan Li Yu-Hua Tang Liu-Guan Ding zhi-Qiang Yin Yu-Lin Chen Yang-Ping Lu Min-Hao Chen Zhong-Yi Li Key Laboratory of space Weather National Center for Space Weather China Meteorological Administration Beijing 100081 China School of Astronomy and space science Nanjing University Xianlin Campus Nanjing 210046 China National Astronomical Observatories Chinese Academy of-Sciences Beijing 100012 China School of Mathematics and Statistics Nanjing University of Information Science and Technology Nanjing 210044China

The intensity-time profiles of solar proton events（SPEs） are grouped into three types in the present study. The Type-I means that the intensity-time profile of an SPE has one peak, which occurs shortly after the associated solar flare and coronal mass ejection（CME）. The Type-II means that the SPE profile has two peaks： the first peak occurs shortly after the solar eruption, the second peak occurs at the time when the CME-driven shock reaches the earth, and the intensity of the second peak is lower than the first *** the intensity of the second peak is higher than the first one, or the SPE intensity increases continuously until the CME-driven shock reaches the earth, this kind of intensity-time profile is defined as Type-III. It is found that most CMEs associated with Type-I SPEs have no geoeffectiveness and only a small part of CMEs associated with Type-I SPEs can produce minor（–50 n T ≤ Dst ≤–3. n T） or moderate geomagnetic storms（–100 n T≤ Dst ≤–50 n T）, but never an intense geomagnetic storm（–200 n T ≤ Dst 〈-100 n T）. However,most of the CMEs associated with Type-II and Type-III SPEs can produce intense or great geomagnetic storms（Dst ≤-200 n T）. The solar wind structures responsible for the geomagnetic storms associated with SPEs with different intensity-time profiles have also been investigated and discussed.

关键词： Sun: coronal mass ejections (CMEs) -- Sun: particle emission -- Sun: solar-terrestrial rela- tions

天语计划——寻找第二个太阳系及探索动态宇宙

在线全文

学校读者我要写书评

暂无评论

天文学报 2024年第4期65卷 1-43页

作者：冯发波芮易成杜芝茂林清张聪聪周丹崔开明 OGIHARA Masahiro 杨明林杰蔡永志杨涛只庞晓莹简明杰李文雄郭恒潇史弦史建春李荐扬郭康柔姚嵩陈啊明贾鹏谭先瑜 JENKINS S.James 蒋宏轩张铭缘李可欣肖光耀郑书玥宣一帆郑捷何敏 JONES R.A.Hugh 宋翠英上海交通大学李政道研究所上海201210 上海交通大学物理与天文学院上海200240 上海天文馆(上海科技馆分馆) 上海200127 中国科学院上海天文台上海200030 同济大学测绘与地理信息学院上海200092 中国科学院星系宇宙学重点实验室(中国科学技术大学) 合肥230026 中国科学技术大学天文与空间科学学院合肥230026 中国科学院云南天文台昆明650216 中国科学院天体结构与演化重点实验室昆明650216 国际超新星中心-云南省国际超新星研究重点实验室昆明650216 西安交通大学物理学院西安710049 西交利物浦大学物理系苏州215123 上海师范大学上海市星系与宇宙学半解析研究重点实验室上海200234 Department of Astronomy Stockholm University Stockholm11421 中国科学院国家天文台北京100101 中山大学大气科学学院珠海519082 太原理工大学电子信息与光学工程学院太原030024 Instituto de Estudios Astrofısicos Facultad de Ingenierıa y CienciasUniversidad Diego Portales Santiago8170641 Centro de Astrof´ısica y Tecnologıas Afines(CATA)Santiago 8480000 山东大学空间与物理学院山东省光学天文与日地空间环境重点实验室威海264209 中国科学院国家天文台中国科学院天文光学技术重点实验室北京100101 Centre for Astrophysics Research University of Hertfordshire HertfordshireAL109AB 清华大学天体物理研究中心北京100084

像木星和土星这样的冷巨行星对类地行星的形成和宜居性起到了关键作用,因此,对像太阳系这样具有多个冷巨行星的系统的搜寻具有重要意义.Kepler以及TESS (Transiting Exoplanet Survey Satellite)太空望远镜成功地通过凌星的方法发现了... 详细信息

像木星和土星这样的冷巨行星对类地行星的形成和宜居性起到了关键作用,因此,对像太阳系这样具有多个冷巨行星的系统的搜寻具有重要意义.Kepler以及TESS (Transiting Exoplanet Survey Satellite)太空望远镜成功地通过凌星的方法发现了大量短周期行星,然而这些巡天项目的观测基线不足以发现更长周期的行星.为此,天语计划将部署两台1m望远镜(天语一号和天语二号),用于结合天语和其他计划的数据通过凌星法来发现冷巨行星及其他行星,并最终发现类太阳系.天语一号具有约10平方度的视场以及高速CMOS (complementary metal-oxide-semiconductor)科学相机,将对超过1000万颗恒星每小时进行一次高精度测光采样,并通过天语二号的多波段测光、光谱仪以及高分辨率成像对天语一号发现的候选行星进行确认.天语望远镜将放置于海拔约4000m的中国青海冷湖,是目前中国境内最好观测台址之一.天语对亮于14等星的测光精度为0.1%,对亮于18等星的测光精度优于1%,天语预计在5yr内将在类太阳周期发现超过3.0颗凌星行星,其中包括约17颗冷巨行星.基于系统轨道共面以及孪生地球发生率为10%的假设,天语预计将发现1-2个类太阳系,并可被未来的地球2.0计划所证实.此外,天语还将通过多种巡天观测模式测量从亚秒到周时标的光变,探测不同时标的时域现象,包括超新星早期光变、稀有变星和双星、潮汐瓦解事件、Be星、彗星活动以及系外小行星等.这些发现不仅将深化我们对宇宙的理解,还将为公众科学和科普提供重要平台.

关键词：技术:测光行星与卫星:探测行星与卫星:形成恒星:超新星:普通恒星:变星:普通小行星:普通恒星:伽马射线暴:普通

Characteristics,Types,and Prospects of Geological Sweet Sections in Giant Continental Shale Oil Provinces in china

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of earth science 2022年第5期33卷 1260-1277页

作者： zhi Yang Caineng Zou Songtao Wu Songqi Pan Xiaoni Wang Haitao Liu Wenqi Jiang Jiarui Li Qiyan Li Xiaobing Niu Guohui Li Zhenxing Tang Xuguang Guo Dong Huang Qizhao Wei Research Institute of Petroleum Exploration&Development PetroChinaBeijing 100083China School of earth and space sciences Peking UniversityBeijing100871 School of Energy China University of GeosciencesBeijing 100083China Research Institute of Exploration and Development PetroChina Changqing Oilfield CompanyXi'an 710021China Research Institute of Exploration and Development PetroChina Daqing Oilfield CompanyDaqing 163712China Research Institute of Exploration and Development PetroChina Jilin Oilfield CompanySongyuan 138000China Research Institute of Exploration and Development PetroChina Xinjiang Oilfield CompanyKelamay 834000China Research Institute of Exploration and Development PetroChina Southwest Oil&Gasfield CompanyChengdu 610051China

“Sweet sections”in giant shale oil provinces are preferential fields that primarily support china to increase the reserves and production of continental shale *** on the study of the geological conditions of shale oil in the continental basins in china,it was found that the shale stratum in major oil generation windows generally has higher degrees of oil and gas accumulation,and mostly contains *** generation and reservoir capacities are the two key parameters for evaluating and optimizing favorable shale oil *** evaluation index(volume of shale stratum multiplied by total organic carbon(TOC)multiplied by total porosity)for the giant continental shale oil provinces is also *** is optimized that the Upper Triassic Chang 7 Member in the southcentral Ordos Basin,Lower Cretaceous Qing 1 Member in the Gulong-Changling Sag in the Songliao Basin,Middle-Lower Permian in the Junggar Basin,Da’anzhai Member of the Ziliujing Formation of Lower Jurassic in the central and northern Sichuan Basin,and Paleogene oil-rich sag in the Bohai Bay Basin are the five giant continental shale oil *** word“geological sweet sections”in continental shale oil provinces of china refers to favorable shale intervals which are relatively rich in oil,with superior physical properties,and more easily modified and developed commercially under applicable economic and technological *** evaluation,there are mainly two types of“geological sweet sections”of giant continental shale oil developed onshore in *** type of“geological sweet sections”is generally mudstone with optimal physical properties or a thin tight reservoir,to which the shale oil migrates a short *** are medium-to-high-mature zones with a thin sandy shale stratum in the Chang 7 Member in the Ordos Basin,mixed shale stratum in the mediummature Lucaogou Formation in the Jimsar Sag,and multi-layered mixed Paleogene shale stratum in the Bohai Bay *** other type of“ge

关键词： continental shale oil shale stratum geological sweet section source rock oil micro-nano pore throats laminae lamination free hydrocarbons shale oil revolution petroleum geology

Survey of autonomous guidance methods for powered planetary landing

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information technology & Electronic Engineering 2020年第5期21卷 652-674页

作者： Zheng-yu SONG Cong WANG Stephan THEIL David SEELBINDER Marco SAGLIANO Xin-fu LIU zhi-jiang SHAO china Academy of Launch Vehicle technology Beijing 100076China Beijing Aerospace Automatic Control Institute Beijing 100854China GNC Systems Department DLR Institute of Space SystemsBremen 28001Germany School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China College of Control science and Engineering Zhejiang UniversityHangzhou 310027China

This paper summarizes the autonomous guidance methods(AGMs)for pinpoint soft landing on celestial *** first review the development of powered descent guidance methods,focusing on their contributions for dealing with constraints and enhancing computational *** the increasing demand for reusable launchers and more scientific returns from space exploration,pinpoint soft landing has become a basic *** the kilometer-level precision for previous activities,the position accuracy of future planetary landers is within tens of meters of a target respecting all constraints of velocity and attitude,which is a very difficult task and arouses renewed interest in *** paper states the generalized three-and six-degree-of-freedom optimization problems in the powered descent phase and compares the features of three typical scenarios,i.e.,the lunar,Mars,and earth *** this basis,the paper details the characteristics and adaptability of AGMs by comparing aspects of analytical guidance methods,numerical optimization algorithms,and learning-based methods,and discusses the convexification treatment and solution strategies for non-convex *** key issues related to AGM application,including physical feasibility,model accuracy,and real-time performance,are presented afterward for *** space organizations,such as those in the United States,{3.,France,Germany,and Japan,have also developed free-flying demonstrators to carry out related *** guidance methods which have been tested on these demonstrators are briefly introduced at the end of the paper.

关键词： Autonomous guidance method Pinpoint soft landing Powered descent Nonlinear programming

一种考虑光谱变异性的高光谱图像非线性解混算法

在线全文

学校读者我要写书评

暂无评论

红外与毫米波学报 2019年第1期38卷 115-124,132页

作者：智通祥杨斌王斌复旦大学电磁波信息科学教育部重点实验室上海200433 北京师范大学地表过程与资源生态国家重点实验室北京100875 复旦大学信息学院智慧网络与系统研究中心上海200433

非线性解混可以解释高光谱图像复杂场景中的非线性混合效应,但地物的光谱变异性是其中的一个难点。提出一种考虑光谱变异性的无监督非线性解混算法。通过核函数将原始高光谱图像数据隐式地映射到高维特征空间中,从而在该空间中结合光谱... 详细信息

非线性解混可以解释高光谱图像复杂场景中的非线性混合效应,但地物的光谱变异性是其中的一个难点。提出一种考虑光谱变异性的无监督非线性解混算法。通过核函数将原始高光谱图像数据隐式地映射到高维特征空间中,从而在该空间中结合光谱变异性进行线性解混;与此同时,依据实际地物的分布特性,添加丰度和光谱变异系数的局部平滑约束。模拟和真实高光谱数据的实验结果表明,该方法能克服不同非线性混合场景中存在的光谱变异性问题,提高光谱解混的精度。

关键词：高光谱图像非线性光谱解混光谱变异性核方法平滑约束

低轨预警卫星引导下的相控阵雷达搜索区域研究

在线全文

学校读者我要写书评

暂无评论

电子科技大学学报 2016年第6期45卷 911-916页

作者：严冬冬李智徐灿装备学院研究生管理大队北京怀柔区101416 装备学院航天指挥系北京怀柔区101416 装备学院航天装备系北京怀柔区101416

在弹道导弹防御过程中,相控阵雷达在预警卫星的引导下能否快速捕获并跟踪目标是开展拦截的关键。该文针对低轨预警卫星引导精密跟踪雷达搜索探测弹道导弹的搜索区域确定问题开展研究。以美国STSS低轨预警卫星为研究对象,首先分析了双星... 详细信息

在弹道导弹防御过程中,相控阵雷达在预警卫星的引导下能否快速捕获并跟踪目标是开展拦截的关键。该文针对低轨预警卫星引导精密跟踪雷达搜索探测弹道导弹的搜索区域确定问题开展研究。以美国STSS低轨预警卫星为研究对象,首先分析了双星联合观测时的探测精度,提出以定位误差克拉美罗界作为跟踪卫星的定位精度,进而研究了测量误差在不同坐标系下的表达式及传递形式。最后,结合相控阵雷达搜索方式,提出并确定了相控阵雷达在指向坐标系下的搜索范围。仿真结果表明,采用该文的分析方法将有助于减小相控阵雷达搜索范围,提高雷达搜索针对性。

关键词：低轨预警卫星相控阵雷达雷达指向坐标系搜索区域

Arrival picking method for microseismic phases based on curve fi tting

在线全文

学校读者我要写书评

暂无评论

Applied Geophysics 2020年第3期17卷 453-464页

作者： Yu zhi-Chao Yu Jing Feng Fang-Fang Tan Yu-Yang Hou Gui-Ting He Chuan Institute of Oil&Gas School of Earth and Space SciencePeking UniversityBeijing 100871China Geophysical Company Shengli BranchSINOPECDongying 257000China. Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 10029China Ocean University of china Qingdao266100

Microseismic phase detection and arrival picking are critical steps in the processing of hydraulic fracturing microseismic monitoring *** the signal-to-noise ratios of P-and S-waves diff er because of the infl uence of focal mechanisms,geometry,and background noise,diffi culties are introduced in the eff ective discrimination of seismic phases and the accurate acquisition of arrivals in conventional processing *** this paper,we propose a method for identifying microseismic phase arrival time by comprehensively analyzing the variation of moveout curves and combining the intra-event waveform similarities with the energy ratio of multitrace ***,a curve-fi tting formula is constructed with perforation arrivals,and event detection is achieved by adopting an energy-weighted similarity coeffi cient that seeks plausible fi tting curves with a sliding time window in continuous microseismic ***,the P-and S-waves are separated by the fitting *** known arrival time trend of the microseismic phase is employed to calculate residual time ***,the accurate arrival results of the microseismic phases can be obtained by picking the arrivals of stacked *** reliability and eff ectiveness of the proposed method for microseismic phase detection and arrival picking were determined through tests using field *** results indicate that the proposed method can improve accuracy compared with the traditional energy ratio method.

关键词： Microseismic moveout curves phase detection arrival picking

Change of ecosystem service value in Menglian county with large-area economic gardens

在线全文

学校读者我要写书评

暂无评论

Ecological Economy 2016年第2期9卷 125-138页

作者： GU Ze-xian ZHAO Xiao-qing Tang Wei Chen Wei-zhi College of Resource Environment and earth science Yunnan University

From the point of spatio-temporal changes of ecological system type,function and value,in Menglian county,land using/cover data was based on three Landsat TM images(respectively obtained in2000,2005,2010 and 2015) which were interpreted as basic information sources by using RS and GIS technology and then revising ecosystem service value per unit area in Menglian *** paper has researched on the changes of ecosystem service value of economic garden for large area planting as well as evaluated ecosystem service value scientifically in Menglian county combined with the sensitivity *** Results showed that:(1) In Menglian county,from 2000 to 2015,land use pattern manifested as the transformation from large areas of cultivated land,forest land and shrub to the economic landscape,the economic landscape is increased by 24458.3. hm^2,however,farm land,wood land and shrub are reduced by 24865.74 hm2 in total;(2) Changes of ecosystem service value is closely related to economic landscape development in Menglian *** situation of ecosystem service value shows the changing trend from improvement to severity in *** is increased by 96.3. million yuan from 2000 to2005,whose annual growth rate is about 0.56%·a^(-1).But in the year of 2005 to 2015,ESV is reduced by120.23.million yuan and annual reduced rate is about 0.3.%·a^(-1);(3. In Menglian county,the main ecological system is the woodland ecological system,the primary ecosystem service functions are biodiversity protection,gas regulation,soil formation and retention,climate regulation and water supply,the ecological benefit were decreased in 2000-2015;(4) From the aspect of space distribution,ecosystem service value in Menglian county is relatively high in the central area and relatively not high in the western and eastern ***(yuan·hm`(-2)) was changed obvious,Gongxin town trended to decline,other towns increased first the then *** temporal and spatial variation of ecosystem service v

关键词： ecosystem service value temporal and spatial variation large area of economic gardens land use/cover change Menglian county