一种低成本、低精度SINS/GPS组合导航系统及试验研究   总被引：3，自引：0，他引：3  

林雪原  刘华章  史佩 《武汉大学学报(信息科学版)》2006,31(10):871-874

在SINS（捷联式惯性导航系统）与GPS组合时，航向角的可观测性较弱，经过卡尔曼滤波后，航向角误差虽有所改善，但仍呈发散趋势，当采用低成本、低精度SINS时，该趋势进一步加剧。为了抑制该发散趋势，针对某型低成本、低精度SINS硬件组成（包括AHRS（姿态和航向参考系统）与IMU（惯性测量器件））的特点，提出了利用AHRS代替SINS航向角信息的方法。实际静态与动态试验表明，利用该方法可有效地抑制组合系统航向角的发散趋势，定位精度较高。  相似文献   

Luobusaite： A New Mineral   总被引：6，自引：0，他引：6  

BAI Wenji SHI Nicheng FANG Qingsong LI Guowu XIONG Ming YANG Jingsui RONG He 《《地质学报》英文版》2006,80(5):656-659

A group of mantle minerals including about 70-80 subtypes of minerals are discovered from a podiform chromitite in Tibet, China. Recovered minerals include diamond, coesite, moissanite, wustite, Fe-silides and a new mineral, luobusaite. All of these minerals were hand-picked from heavymineral separates of the podiform chromitite in the mantle peridotite of an ophiolite. The grains of luobusaite are as host mineral with inclusions of native silicon or as an intergrowth with native silicon and Fe-Si phase. Luobusaite occurs as irregular grains, with 0.1-0.2 mm in size, consisting of very finegrained aggregates. The mineral is steel-grey in color, metallic luster, and opaque. The empirical formula （based on 2 for Si） is Fe0.83Si2, according to the chemical compositions of luobusaite. X-ray powder-diffraction data： orthorhombic system, space group Cmca, a = 9.874 （14） A, b = 7.784 （5） A, c= 7.829（7） A, Z=16.  相似文献   

Junction and Evolution of the Qinling, Qilian and Kunlun Orogenic Belts   总被引：2，自引：0，他引：2  

SUN Yangui  CHEN Zhengxing  LIU Yong''an  WANG TongqingQinghai Regional Survey  Comprehensive Geological Party  Nanchuan West Ro  Xining  Qinghai Province  ZHANG Zhiyong Qinghai Institute of Geological  Mineral Exploration  Xining  Qinghai 《《地质学报》英文版》2000,74(2):223-228

As the main part of the "central mountain system" in the continent of China, the Qinling, Qilian and Kunlun orogenic belts have been comprehensively and deeply studied since the 1970s and rich fruits have been reaped. However, these achievements were mostly confined to an individual orogenic belt and the study of the mutual relationship among the three orogenic belts was obliged to depend on comparative studies. Different views were produced therefrom. The material composition and structural features of the junction region show that there are several epicontinental and intracontinental transform faults developed in different periods. Restricted by these transform faults, the large-scale lateral movements and, as a consequence, complicated magrnatism and tectonic deformation took place in the orogenic belts. According to these features, the authors put forward a three-stage junction and evolution model and point out that there is not a single junction zone traversing from west to east but that the three  相似文献   

CNS/SINS组合导航系统的UKF算法研究     

朱璐瑛  林雪原  王萍  许家龙  陈祥光 《大地测量与地球动力学》2022,42(12):1216-1221

天文/捷联惯性（CNS/SINS）组合导航系统采用姿态组合,可使姿态角处于收敛状态,并有效抑制位置及速度的发散。为提高组合导航系统的精度,本文设计了CNS/SINS组合导航系统的UKF算法,在建立CNS/SINS组合导航系统非线性状态方程及线性量测方程的基础上,首先对UKF的量测更新过程进行简化,降低其计算量;然后,基于平台误差角提出系统状态协方差矩阵中姿态角协方差矩阵的计算方法,并推导了UKF算法中姿态量测值一步预测误差对应的平台角误差向量表达式,进而建立CNS/SINS组合导航系统的UKF算法;最后进行仿真实验。结果表明,相对于线性卡尔曼滤波算法及EKF算法,本文算法可明显提高组合导航系统的各导航参数精度,并且本文算法对滤波器初始姿态角误差变化具有较高的鲁棒性。  相似文献   

Synergetic Network Evolution of Mineral Exploitation on the Water Environment in the Yangtze River Economic Belt     

Sun  Han  Wang  Hai  Hu  Xueyuan 《Natural Resources Research》2020,29(6):3581-3598

Achieving the coordinated development of mineral exploitation and the water environment (the mine–water system, MWS) is an urgent difficulty in the construction of China’s ecological civilization. Based on the theory of synergy, a synergetic model was used to construct a network of the MWS, and then, social network analysis was applied to study the network characteristics for ten provinces of the Yangtze River Economic Belt. The research results show that the natural water system has always been at the center of the MWS, and water conservancy construction is particularly critical. However, the synergistic effect is not strong between the water environmental stress system and other systems, and as a result, the water environment is under great pressure. Among the crucial factors, the discharge of wastewater and solid waste is at the core of the network and directly affects the coordinated development trend of the MWS. However, the sustainable development of the water environment is better achieved by the treatment of solid waste than by the control of wastewater discharge. Generally, the synergistic relationship based on the natural water system is very important. At the same time, the core role of the water environmental protection system should be strengthened by adjusting sequence parameters to promote the overall coordinated development of the MWS.

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南极冰盖数值模拟研究进展与展望          下载免费PDF全文

唐学远  张占海  孙波 《极地研究》2006,18(4):290-300

数值模拟南极冰盖是提升人们认识南极冰盖演化行为的重要手段。通过数值模拟研究可以揭示某些观测数据包含的冰盖物理机理以及在缺乏观测数据的情形下预测冰盖的演化行为。本文在综述南极冰盖数值研究国际进展的基础上,分析了南极冰盖数值模拟方面几个主要模型的特点,特别针对南极冰盖的三维数值模拟展开讨论,分析并探讨了冰盖数值模拟可能会遇到的潜在不稳定源以及在拓展模型研究范围时会遇到的障碍。对目前三维冰盖数值模拟存在的几个问题进行了讨论,并对未来发展进行了展望。  相似文献   

High Temperature as a Mechanism for Plant Cytoplasm Preservation in Fossils     

WANG Xin 《《地质学报》英文版》2007,81(2):183-193

Because the cytoplasm of a plant normally degrades after the death of the plant, finding cytoplasm in a plant body after a prolonged period of time, especially in fossil plants, is unexpected. Recent work on several 100-Myr-old plant fossils from Kansas, USA indicates, however, that cells and their contents can be preserved. Most of the cells in these fossil plants appear to be in a state of plasmolysis, and these fossil cells bear a strong resemblance to laboratory-baked cells of extant plant tissues. Based on a comparison with extant material plus biophysical and biochemical analyses of the cytoplasm degrading process, a new hypothesis for cytoplasm preservation in nature is proposed： high temperature, a concomitant of commonly seen wildfires, may preserve cytoplasm in fossil plants. This hypothesis implies that fossilized cytoplasm should be rather common and an appropriate substance for research, unlike previously thought. Research on fossil cytoplasm closely integrates paleobotany with biochemistry, biophysics, as well as fire ecology, and invites inputs from these fields to paleobotany to interpret these provocative findings.  相似文献   

TOF-SIMS Study of the Hydrocarbon-generating Potential of Mineral-Bituminous Groundmass   总被引：5，自引：0，他引：5  

DAI Shifeng  REN Deyi  YANG Jianye  ZHANG Weibiao  JIAO FangliBeijing Graduate School  China University of Mining  Technology  P.O. Box  D Xueyuan Ro  Beijing 《《地质学报》英文版》2000,74(1):84-92

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Mineral Surface after Reaction with Aqueous Solution at High Temperatures and Pressures     

ZHANG Xuetong  ZHANG Ronghu  HU Shumin  YU WenbinOpen Research Laboratory of Geochemical Kinetics  Chinese Academy of GeologicalSciences  Baiwanzhuang Ro  Beijing 《《地质学报》英文版》2000,74(2):406-411

This work presents new experimental results on surface chemistry of reacting minerals and interface kinetics between mineral and aqueous solutions. These experiments were carried out using a flow reactor (packed bed reactor) of an open system as well as a continuous stirred tank reactor, CSTR. The authors measured reaction rates of such minerals as zeolite, albite and carbonate (rhodochrosite, dolomite) in various solutions, and tested corresponding mineral surface by using SEM, XPS, SIMS, etc. This paper mainly presents the experimental results of zeolite dissolution in water and in low pH solutions at room temperature, and dolomite dissolution at elevated temperatures. The results show that the release rates of Si, Al and Na of zeolite are different in most cases. The incongruent dissolution of zeolite is related to surface chemical modifications. The Na, Al and Si release rates for dissolution of albite and zeolite in water and various solutions were measured as a function of temperature, flow veloci  相似文献   

地图线状要素眼动识别的朴素贝叶斯方法     

董卫华  王圣凯  王雪元  杨天宇 《测绘学报》2021,50(6):749-756

眼动追踪技术在人机交互、用户行为识别、预测等方面得到了广泛应用,但是如何自动识别用户的地图阅读行为,眼动行为仍具有一定的挑战性.本文提出了一种基于朴素贝叶斯分类模型的方法识别用户阅读地图线状要素时的眼动行为.本试验首先通过25名被试者阅读地图过程中的眼动行为进行数据采集,然后提取了250个眼动特征并对其进行离散化处理,...  相似文献