面向LiDAR/Radar松组合的迭代加权IEKF-BP组合算法精度分析

为了验证目前高精度定位中多传感器组合定位模型性能的优越性,以更好地解决自动驾驶场景下自主定位中出现的预测精度标准不一致、预测不及时及误预测率高等问题,本文利用LiDAR与Radar数据,建立了一种基于迭代加权的IEKF-BP组合算法的松组合模型,并对两种传感器组合定位结果精度进行了分析.试验表明,迭代加权的IEKF-B...     

1961 - 2017年中国东北地区降雪时空演变特征分析

利用东北地区162个气象台站逐日降水量和天气现象数据, 采用统计分析方法, 对近57年（1961 - 2017年）降雪的气候特征和时空演变规律进行了分析。结果表明： 降雪量和降雪日数最多出现在12月, 小雪和中雪最多出现在11月或12月, 大雪和暴雪在冬末春初出现概率最高。降雪分布为山地大于平原, 平原地区自北向南、 自东向西减少, 降雪高值区主要位于大兴安岭北部、 小兴安岭和长白山区, 降雪强度中心位于长白山区和辽宁中部平原地区。年、 秋季、 冬季、 春季降雪量占同期降水量比例分别为4.7%、 7.0%、 84.4%和7.6%; 辽宁省西部山区和南部大连地区日最大降雪量占年总降雪量比例最高, 最长连续降雪日数在2 d以下, 降雪较高纬度地区更为集中。近57年降雪量和降雪强度分别以1.93 mm?（10a）^-1和0.11 mm?d^-1?（10a）^-1的速率显著增加, 降雪日数以2.08 d?（10a）^-1速率显著减少; 降雪量增加主要表现为各等级降雪量的增加, 降雪日数减少主要是微量和小雪日数的减少, 降雪强度增加主要为大雪和暴雪降雪强度的增加。年、 秋季和冬季降雪量占同期降水量比例平均每10年增加0.36%、 0.48%和0.45%, 春季以0.11%?（10a）^-1的速率减少。中雪、 大雪和暴雪对降雪贡献率均呈增加趋势, 小雪降雪量和微量降雪日数贡献率减少; 1987年降雪量和降雪日数突变后, 微量降雪日数和暴雪日数、 小雪降雪量贡献率改变显著。就区域平均而言, 2001 - 2017年的降雪量较1961 - 1980年增加了27.8%, 降雪日数减少了22.4%。     

Constraints of Mantle and Crustal Sources Interaction during Orogenesis of Pre- and Post-collision Granitoids from the Northern Arabian-Nubian Shield: A Case Study from Wadi El-Akhder Granitoids,Southern Sinai,Egypt

The Egyptian older and younger granitic rocks emplaced during pre- and post-collision stages of Neoproterozoic Pan-African orogeny, respectively, are widely distributed in the southern Sinai Peninsula, constituting 70% of the basement outcrops. The Wadi El-Akhder, southwestern Sinai, is a mountainous terrain exposing two granitoid suites, namely the Wadi El-Akhder Older Granites (AOG) and the Homra Younger Granites (HYG). The AOG (granodiorites with subordinate tonalite compositions) have geochemical characteristics of medium-K calc-alkaline, metaluminous to mildly peraluminous granitoids formed in an island-arc environment, which are conformable with well-known Egyptian older granitoids rocks, whereas the HYG display calc-alkaline to slightly alkaline nature, peraluminous syeno-, monzogranites and alkali feldspar granites matching well those of the Egyptian younger granites. With respect to the AOG granitoids, the HYG granites contain lower Al2O3, FeO*, MgO, MnO, CaO, TiO2, Sr, Ba, and V, but higher Na2O, K2O, Nb, Zr, Th, and Rb. The AOG are generally characterized by enrichment in LILE and LREE and depletion in HFSE relative to N-MORB values (e.g., negative Nb and Ta anomalies). The geochemical features of the AOG follow assimilation-fractional crystallization (AFC) trends indicative of extensive crustal contamination of magma derived from a mantle source. The chemical characteristics of the AOG are remarkably similar to those of subduction-related granitoids from the Arabian-Nubian Shield (ANS). The compositional variations from monzogranites through syenogranites to alkali feldspar granite within HYG could not be explained by fractional crystallization solely. Correlating the whole-rock composition of the HYG to melts generated by experimental dehydration melting of meta-sedimentary and magmatic rocks reveals that they appear to be derived by extended melting of psammitic and pelitic metasediments, which is similar to the most of younger granitic suites in the ANS.     

The Knorre astronomers' dynasty

We attempt to throw light upon the poorly known astronomical dynasty of Knorre and describe its contribution to astronomy. The founder of the dynasty, Ernst Christoph Friedrich Knorre (1759–1810), was born in Germany in 1759, and since 1802 he was a Professor of Mathematics at the Tartu University, and observer at its temporary observatory. He determined the first coordinates of Tartu by stellar observations. Karl Friedrich Knorre (1801–1883) was the first director of the Naval Observatory in Nikolaev since the age of 20, provided the Black Sea navy with accurate time and charts, trained mariners in astronomical navigation, and certified navigation equipment. He compiled star maps and catalogues, and determined positions of comets and planets. He also participated in Bessel's project of the Academic Star Charts, and was responsible for Hora 4, published by the Berlin Academy of Sciences. This sheet permitted to discover two minor planets, Astraea and Flora. Viktor Knorre (1840–1919) was born in Nikolaev. In 1862 he left for Berlin to study astronomy. After defending his thesis for a doctor's degree, he went to Pulkovo as an astronomical calculator in 1867. Since 1873 Viktor worked as an observer of the Berlin Observatory Fraunhofer refractor. His main research focussed on minor planets, comets and binary stars. He discovered the minor planets Koronis, Oenone, Hypatia and Penthesilea. Viktor Knorre also worked on improving astronomical instrumentation, e.g. the Knorre & Heele equatorial telescope mounting (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Contrasting water–rock interaction behaviors of antimony and arsenic in contaminated rivers around an antimony mine,Hunan Province,China

Although antimony (Sb) and arsenic (As) exhibit similar geochemical behavior and toxicity in the environment, growing evidence suggests that their water–rock interaction behavior in contaminated rivers is quite different. Twenty-nine river water samples were collected between September and November 2018 from contaminated rivers around an antimony mine in Hunan Province, China. The concentrations of As and Sb were inversely proportional to the water flow distance. The rates and magnitudes of Sb decrease were more prominent than those of As. Silicate mineral dissolution from rocks such as silicified limestone increased the As and Sb concentration of in-mine-district (IMD) water. Dissolution of carbonate minerals, ion exchange, and competitive adsorption were the major water–rock interactions, resulting in rapidly decreasing As and Sb concentration in IMD direct impacted water and IMD indirect impacted water. The behaviors of As and Sb during water–rock interaction were dissimilar for areas dominated by carbonate and silicate minerals.     

江西利山金矿床地质特征及控矿构造

本文较系统地阐述了利山金矿床的各项地质特征，并重点就控矿构造问题进行了总结讨论，认为ＮＷＷ向断裂带严格控制了所有金矿体的产出。ＮＮＥ、ＮＮＷ向断裂与ＮＷＷ向断裂带的交汇部位控制了富矿段的产出。在此基础上初步探讨了矿床成因及找矿方向，这对该地区的找矿评价和开发均具有实际意义     

沁水盆地南部潘庄区块废弃矿井煤层气地球化学特征及成因

为了研究废弃矿井中煤层气成因,以沁水盆地南部潘庄区块废弃矿井为例,抽采废弃矿井中煤层气并进行化学组分和同位素测试,并采集部分废弃矿井水样品测试水中离子浓度、pH值等进行研究。结果表明：潘庄区块废弃矿井中煤层气CH₄体积分数平均值为91.99%,CO₂为1.26%,N₂为6.73%;甲烷碳同位素（δ¹³C₁）值为-31.36‰~-33.53‰,平均-32.25‰,氢同位素（δD）值为-182.76‰~-193.20‰,平均-187.538‰。废弃矿井排采水中阴阳离子主要为Mg²⁺、K⁺、HCO₃^-、Cl^-、Na⁺、SO₄^2-和NO₃^-等,产出水型为Mg-（HCO₃）₂型,表明矿井水受到地表水的强烈影响。废弃矿井中煤层气主要以热成因气为主,少量次生生物气。与附近未开采煤储层相比,研究区废弃矿井中的环境更有利于次生生物气的生成。     

区域矿产资源技术经济评价方法的研究

矿产资源是国民经济发展的重要物质基础。因此,一个区域经济发展战略或规划的制定,都把矿产资源技术经济评价成果作为重要的依据。但国内、外在这方面的研究和实践多只限于某一单矿种或某一矿组;多矿种综合性的定量评价实例尚未见到。本文以区域内所有矿种的矿床、矿点、矿化点构成的整体,在地质评价的基础上,于技术可行的条件下对探明的矿产可利用储量在未来一定时期内进行工业开发的经济评价的理论和方法进行了研究。先以区内大量地质勘查和开发利用的实际资料,对矿产资源优劣类型进行定量评判,论述矿产资源经济价值,以其为基础对矿产资源经济区进行划分。再按区内优势矿产资源进行开发系统评价,并分别提出开发对策意见。最后论述矿产资源技术经济评价的主要结论,总结矿产资源开发中的主要问题,提出切实可行的措施和建议。     

内蒙古萤石矿资源开发利用动态分析与建议

萤石是一种稀缺性战略资源。内蒙古萤石资源丰富,保有资源储量稳定。分析了内蒙古萤石资源储量动态、开发利用动态以及市场需求和发展动态,提出了加强萤石矿地质勘查工作,优化管理、节约资源,加快企业进步、抬升综合效益,改善下游消费结构、实现资源整体升值的未来发展建议。