一种异步多传感器组合导航系统融合算法

针对不同导航传感器存在的采样率不同步（或尺度不同）,提出了一种基于状态方程多尺度变换的异步多传感器组合导航系统信息融合算法。仿真结果表明,本算法不仅具有较好的实时性,而且具有较好的融合精度。     

据索尔库都克铜-钼矿床地化特征探讨其成因类型

索尔库都克铜(钼)矿床,主要赋存于辉石闪长玢岩外接触带的安山质岩石中。除Cu,Mo外,Ca,Fe,Mn,Pb,Zn,Ti,Cr,Ni和Co含量也较高。Si,Na,K和REE含量最低,具一套与中基性岩有关(矿床)的元素组合特征。索尔库都克铜(钼)矿的同位素特征与辉石闪长玢岩相近,类似美洲的依尔·萨尔瓦多斑岩铜矿。因此,笔者认为该矿是与辉石闪长玢岩有关的斑岩型矿床。     

Differential Rotation of Stable Recurrent Sunspot Groups

Stable recurrent sunspot groups from the Greenwich data set which were identified in at least two subsequent solar rotations were traced. The solar rotation was determined by the period method from the time difference of the two central meridian passages of each of the 327 identified groups. Sidereal rotation periods were calculated from the synodic ones by a seasonal-dependent procedure taking into account the details of the Earth's motion around the Sun. Growing recurrent sunspot groups rotate on the average faster than decaying recurrent sunspot groups, while sunspot groups of all types taken together rotate faster than both growing and decaying recurrent sunspot groups. A north–south rotational asymmetry and a cycle-dependence of rotational velocity of recurrent sunspot groups were analyzed. Positive rotation velocity deviations are larger, but less numerous than the negative ones. Signatures of torsional oscillations were not found analyzing the rotation velocity residual of recurrent sunspot groups as a function of the distance from the average latitude of activity.     

A New Genetic Type of Gold Deposits-Meso-Epithermal Carbonate-Type Gold Deposits as Exemplified by the Baguamiao Suprlarge Gold Deposit

Gold deposits of the meso-epithermal carbonate type were first proposed based on the study of the Baguamiao gold deposit.This new type of gold deposits has many unique characteristics as follows:(1)Obviously strata-bound.The gold deposits are hosted in Middle Devonian turbidite formations;(2)Structrually controlled.Struc-ture is an important factor leading to metallogenesis of this type of gold deposits.The shape and distribution of orebodies are controlled by byittle-ductile shear zones;(3)Multi-stage wall-rock alteration.According to the characteristics of mineral assemblage,gold mineralization can be classified into three stages in association with various wall-rock al-terations.Wall-rock alterations closely genetically related to the gold mineralization are ankerization ,silicification,pyrrhotization and pyritization ;(4)Mineral compositions of the orebodies are mainly pyrrhotite,pyrite,marcasitolite,chalcopyrite,quartz,ankerite,and sericite.Gold mineralization is associated closely in space and time with iron sulfides;(5)Rare elements and REE in ores are low in contents relative to those of the crust.Au content varies from 1.91g/t to 11.15g/t ,averaging 5.5g/t;(6)Studies of sulfur,hydrogen,oxygen and carbon isotopes in main gangue minerals (quartz and ankerite)indicate that fluids and ore-forming materials came from deep-seated sources;(7)Three types of inclusions are recognized in terms of their composition and the vapor amounts of inclusions.The homogenization temperatures of inclusions range from 210℃to 310℃,averaging 230℃,showing that this type of gold deposits belongs to the meso-epithermal type;(8)Metallogenic age of this type of gold deposits is similar to that of the collision between the Yangtze Plate and the North China Plate,indicating that gold deposits of this type are genetically related to continental-margin plate activity.     

一种低成本、低精度SINS/GPS组合导航系统及试验研究

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。     

南极冰盖数值模拟研究进展与展望

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。     

Regional Air Quality Modelling in Canada – Applications for Policy and Real-Time Prediction

Acid rain and photochemical smog are two regionalair-quality issues that have received considerableattention in the last two decades due to their harmfuleffects. Health impacts of particulate matter (PM) inthe atmosphere is another issue of concern.Sulphur dioxide emission controls were introducedin both Canada and the U.S.A. to reduceacid-deposition-related damage. While these emissionreductions have already resulted in reduced sulphatedeposition, based on results from modelling studiesmuch of southeastern Canada is still expected toexperience damaging levels of acid deposition evenafter all currently legislated emission controls arefully implemented. Moreover, there has not been acorresponding reduction in the acidity ofprecipitation. This may be attributable to aconcurrent reduction in base-cation concentration inprecipitation.Models were also developed to understand theformation, transport and diffusion of troposphericozone. The models have been used to provide policyguidance for emission control options to reduceground-level ozone to acceptable limits. In thesummer of 1997 a Canadian pilot project was initiatedto provide real-time forecasts of ground-level ozonein the southeastern part of the province of NewBrunswick in eastern Canada.With the emergence of fine Particulate Matter(PM_2.5) as a health concern, efforts are underwayin Canada to develop a unified' regional air-qualitymodel that will address the combined impacts ofvarious pollutants in the atmosphere. In this effortthe atmosphere is viewed as a single entity where theimpacts of multiple pollutants are considered at thesame time.     

地图线状要素眼动识别的朴素贝叶斯方法

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,采用最小冗余最大相关方法进行特征选择排序.结果显示,当采用信息熵法,特征数量为m=5时分类准确率最大为78.27％;而采用信息差法,特征数量为m=4时分类准确率达到最大值为77.01％.本文提出的基于朴素贝叶斯的方法在准确率方面优于已有研究方法.此外,由于特征数量的减少,大幅提高了算法的执行效率.本文提出的地图阅读行为眼动识别方法,为未来眼控交互式地图研究奠定基础.     

CNS/SINS组合导航系统的UKF算法研究

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。     

The aerosol radiative effect on a severe haze episode in the Yangtze River Delta

Due to increased aerosol emissions and unfavorable weather conditions, severe haze events have occurred frequently in China in the last 10 years. In addition, the interaction between the boundary layer and the aerosol radiative effect may be another important factor in haze formation. To better understand the effect of this interaction, the aerosol radiative effect on a severe haze episode that took place in December 2013 was investigated by using two WRF-Chem model simulations with different aerosol configurations. The results showed that the maximal reduction of regional average surface shortwave radiation, latent heat, and sensible heat during this event were 88, 12, and 37 W m^–2, respectively. The planetary boundary layer height, daytime temperature, and wind speed dropped by 276 m, 1°C, and 0.33 m s^–1, respectively. The ventilation coefficient dropped by 8%–24% for in the central and northwestern Yangtze River Delta (YRD). The upper level of the atmosphere was warmed and the lower level was cooled, which stabilized the stratification. In a word, the dispersion ability of the atmosphere was weakened due to the aerosol radiative feedback. Additional results showed that the PM_2.5 concentration in the central and northwestern YRD increased by 6–18 μg m^–3, which is less than 15% of the average PM_2.5 concentration during the severely polluted period in this area. The vertical profile showed that the PM_2.5 and PM₁₀ concentrations increased below 950 hPa, with a maximum increase of 7 and 8 μg m^–3, respectively. Concentrations reduced between 950 and 800 hPa, however, with a maximum reduction of 3.5 and 4.5 μg m^–3, respectively. Generally, the aerosol radiative effect aggravated the level of pollution, but the effect was limited, and this haze event was mainly caused by the stagnant meteorological conditions. The interaction between the boundary layer and the aerosol radiative effect may have been less important than the large-scale static weather conditions for the formation of this haze episode.