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谢方  程传录  王斌  蒋光伟  马新莹  李春晓 《大地测量与地球动力学》2015,35(2):258-260

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基于iBeacon的精细室内定位方法研究     

张倬胜  马方方  薛静远  艾浩军 《地理信息世界》2015,(2):26-30

苹果公司发布的i Beacon作为一种粗精度位置感知服务体系,得到了广泛关注。针对更精细的广域位置服务,提出了基于i Beacon的无线指纹定位方法,并给出了图书馆的位置服务示例。  相似文献   

Abundance and Distribution of Fatty Acids in Sediments of the South Mid-Atlantic Ridge     

HUANG Xin  ZENG Zhigang  CHEN Shuai  YIN Xuebo  WANG Xiaoyuan  MA Yao  YANG Baoju  RONG Kunbo  SHU Yunchao  JIANG Tao 《中国海洋大学学报(英文版)》2015,(2):277-283

Sediment samples obtained from the South Mid-Atlantic Ridge were studies by gas chromatography-mass spectrometer(GC-MS) for the abundance and distributions of total fatty acids(TFAs). Approximately 34 fatty acids were identified, with the chain-lengths ranging from C12 to C30. The total concentrations of TFAs(∑TFA) ranged from 7.15 to 30.09 μg g-1 dry sediment, and ∑TFA was weakly correlated with bitumen content(R2 = 0.69). The ∑TFA of samples around hydrothermal areas were significantly higher than that of samples away from hydrothermal areas, indicating intense primary production and large biomass in the hydrothermal areas, and suggesting a close relationship between hydrothermal activity and ∑TFA of samples. The characteristics of the TFA composition in the present study are rich in monounsaturated fatty acids and lacking in polyunsaturated fatty acids, and the ratios between the concentrations of monounsaturated fatty acids and ΣTFAs in samples close to the hydrothermal areas, are about 0.8, but for samples far from the hydrothermal areas, they are only about 0.5. Several fatty acids(e.g., a/i C15:0 and C16:1ω7), which are signature biomarkers for sulfur-metabolizing bacteria, show the same distribution trend as ∑TFA of samples, further highlighting the close relationship between fatty acid content and hydrothermal activity and/or hydrothermal communities. The metabolic activities of hydrothermal communities, especially those of microorganisms, are likely the main source of fatty acids in samples.  相似文献   

Species Composition and Diversity of Macrobenthos in the Intertidal Zone of Xiangshan Bay,China     

JIAO Haifeng  ZHENG Dan  YOU Zhongjie  XU Nianjun  LOU Dan  HUANG Chengwei 《中国海洋大学学报(英文版)》2015,(2):375-384

Xiangshan bay is a narrow semi-closed bay and situated on the northwestern coast of the East China Sea. Over past decades, it has become to a major bay with intensive human activities, dense urbanized area, and poor water quality. The aim of this paper was to reveal the ecological status through the elucidation of the species composition, abundance, biomass and diversity of macrobenthos in this bay. Six intertidal sections were surveyed from January 2007 to November 2008 quarterly. Sections TG, HD and XH are located in the three inner bays, sections QJ and WS are located near the thermal power plants, and section XX is located at the outer part of Xiangshan Bay. Great variations in macrobenthos community were indentified, and the species composition of the community in the present study showed the dominance in the order of molluscs(bivalves and gastropods), crustaceans and others, and only few Polychaeta were recorded. Only three dominant species, Littorina brevicula, Ilyplax tansuiensis, and Cerithidea cingulata were collected in all the sections, and a total of 19 dominant species were recorded only in one section. Two-way ANOVA analyses of abundance indicated that there were significant differences among sections or seasons. Shannon-Wiener diversity index(H’) had its maximum(2.45) in section QJ, and minimum(1.76) in section TG. Multiple irregular k-dominance plots clearly showed that the study area was polluted and the macrobenthos community was under stress. We conclude that the macrobenthos of Xiangshan Bay have been disturbed by human activities, especially at the interior bay.  相似文献   

三山岛北部海域金矿勘查工作思路与实践          下载免费PDF全文

刘殿浩  张丕建  丁正江  张军进  林大伟  马宾 《山东国土资源》2015,31(2):1-6,11

三山岛北部海域金矿床位于胶东西北部三山岛成矿带之中,为一严格受断裂构造控矿的超大型破碎带蚀变岩型金矿床。矿体全部赋存于滨海海域,具有规模大、延伸稳定、有用物质分布较均匀的特点。作为国家级首批整装勘查区的一部分,尤其是首次在浅海海域进行深部勘查,该区勘查工作受到了多方重视、关注和支持,在1年的时间里完成了主要靶区的详查工作。它首开我国浅海海域金矿勘查的先河,是在综合分析研究矿田成矿背景与找矿潜力的基础上开展的一次系统的、由预查开始直接完成详查的勘查活动,具有周期短、规模大、成果丰、效果好的特点,对我国以后海域固体矿产勘查工作具有一定的借鉴意义。  相似文献   

结合张量与互信息的混合模型多模态图像配准方法     

李培  姜刚  马千里  薛万峰  杨伟华 《测绘学报》2021,50(7):916-929

多模态图像之间存在显著的非线性强度差异,并且图像会因为噪声而退化,因此,多模态图像自动配准是一项具有挑战性的任务.为了解决这两个问题,本文提出一种多模态图像自动配准方法,该方法分为预配准和精配准两个阶段.在预配准阶段,通过改进SIFT算法来大致对齐多模态图像.在精配准阶段,首先,利用块Harri s检测器在预配准后的参考图上提取均匀分布的特征点.然后,通过各向异性结构张量捕捉多模态图像中的结构信息来构建特征描述符,该特征描述符对噪声具有稳健性.更进一步,本文结合张量方向平行度和梯度互信息提出了一种相似度准则(tensor orientation and mutual information,TOMI).最后,本文用多种模态图像(包括Optical,LiDAR,SAR和Map)来评估提出的方法.试验结果表明,本文提出的方法对非线性强度变化和噪声具有较好的稳健性,并且匹配效果优越.  相似文献   

虚拟仿真技术在测绘工程实践教学中的应用     

岳祥楠  贺小星  马飞虎  曾聪 《测绘工程》2021,30(1):76-80

实践教学是测绘工程本科教学中不可缺少的关键环节,文中结合当前测绘专业实践教学需求及其存在的不足,构建多种实验组合的虚拟仿真实践教学平台,实现网上演示教学、训练、实践指导和考核反馈等功能,形成"产-学-研"合一的实践教学体系.该平台便于学生课外自主学习,丰富实践教学的项目,实现精细化教学质量控制,发展学生的创新思维和综合应用能力,可供其他对仪器操作技能要求较高的类似课程或专业开展网络教学和构建实践教学平台借鉴.  相似文献   

论新型基础测绘体系建设     

王丹  耿丹  李丹彤 《北京测绘》2021,35(7):833-838

基础测绘作为测绘事业的核心组成部分,具有法定性、战略性、公益性和专业性.新型基础测绘要在承载法律法规赋予的法定任务基础上,面向自然资源管理、国土空间规划、工程建设管理、公共安全与应急管理以及其他政务管理和公众服务等对公共测绘地理信息成果及服务的需要,建立由理念、成果、服务、技术和机制等要素构成的新型基础测绘体系,提升基础测绘的发展质量,并引领测绘地理信息行业的转型升级.本文首先提出新型基础测绘的发展理念,进而对新型基础测绘的基本任务、主要特征和体系建设中的数据精准化、成果体系化、服务便捷化、手段智能化等问题进行探讨并提出建议.  相似文献   

利用高分影像和珞珈一号数据进行住房空置率高精度空间估算     

张栋  李德平  周亮  黄金侠  高航  王嘉丞  马宇 《测绘通报》2021,(1):41-46,52

本文主要利用珞珈一号夜间灯光数据和高分遥感影像数据,提出了一种对研究区按建成区高层区、建成区低层区和非建成区住房进行空置率分区块估算的方法,采用夜晚实地记录的方法对估算结果进行精度检验,并通过LISA聚集图分析其空间聚集情况。表明结果：①研究区整体住房空置率为17.88%,均方根误差为0.14,其中非建成区的住房空置率整体上要高于建成区,而满置率却低于建成区;②研究区住房空置率呈高高集聚和低低集聚两种空间集聚特征,为进一步大范围了解农村地区住房情况及整体的空间分布规律提供了参考。  相似文献   

基于SAR-SIFT改进的SAR图像配准     

李培  姜刚  马千里 《测绘通报》2021,(2):30-35,71

合成孔径雷达（SAR）图像配准时,由于受到乘性散斑影响,匹配算法的性能受到限制。SAR-SIFT使用ROEWA算子代替差分算法计算梯度,对SAR图像的散斑具有一定的稳健性。为了进一步抑制散斑噪声,本文提出了基于SAR-SIFT改进的SAR图像配准算法。利用非线性扩散滤波生成SAR图像的非线性扩散尺度空间,在非线性尺度空间不同尺度层上计算对应的SAR-Harris函数。为了使非线性尺度空间对散斑噪声具有稳健性,在其构造过程中的梯度信息采用ROEWA算子计算。此外,利用相位一致性信息去除初始关键点中由散斑引起的虚假点。多源、多极化、多时相的SAR图像试验结果表明,与SAR-SIFT算法相比,本文算法对散斑噪声更具稳健性,提高了图像匹配性能。  相似文献