区域重力调查成果在江苏地区高精度水准测量改正中的适用性分析

本文分析了空间重力异常精度对水准测量高差重力异常改正的影响。在江苏两处试验区分别采用实测重力和布格异常数据库两种改正方法,计算测段重力异常改正值,对比两者间的差异。结果表明：未顾及地形起伏的实测重力点分布是导致两种改正方法改正值差异大的主要因素;地形起伏较大区域,水准线路出现转折或倾斜过大时,需加测重力,采用实测重力进行水准测量高差重力异常改正;平坦小区域内,利用布格异常数据库与实测重力进行水准测量高差重力异常改正的精度相当。     

双源组合导航系统关键算法研究

针对基于伪距、伪距率的北斗/捷联惯导组合导航系统开展了前期的理论研究,介绍了卫星/惯导组合导航系统中松组合、紧组合和超紧组合的基本原理,并建立了以伪距、伪距率为观测量的北斗/捷联惯导组合导航系统的状态方程和量测方程,设计了卡尔曼滤波参数,仿真验证了基于伪距、伪距率的组合导航系统能够有效的抑制捷联惯导系统的位置和速度误差随时间发散的特性,取得了良好的效果。仿真结果显示,北斗/捷联惯导组合导航系统失准角误差优于0.03°,东方向和北方向的位置误差和速度误差分别优于10m和1m/s。     

黔东留茶坡组硅质岩元素地球化学特征与形成环境

黔东晚震旦世一早寒武世留茶坡组硅质岩,具有展布广、层位稳、厚度大等特征,并具有热水沉积的岩石学证据。代表性剖面硅质岩主量元素分析结果显示,ｗ（SiO：）为93．41％一96．32％,均值95．23％,表示其为化学成分纯净的硅质岩;TFeO、MnO相对富集,A12O3、TiO2、MgO含量相对较低,与热水沉积物相似,表明具有热水沉积特征;研究区硅质岩的Ba／Sr和U／Th等比值均大于1,以及稀土总量偏低（∑REE为9．22×10^6～24．04X10^6）,Ce负异常（0．44～0．76）,重稀土富集等特征,表现出热水沉积岩的元素地球化学特征;而其At／（A1＋Fe＋Mn）、K2O／Na20、CaO／（CaO＋Fe）和MgO／A12O3等比值的均值分别为0．46,1．86,0．33和0．19,也暗示出研究区热水沉积硅质岩受到一定程度陆源物质的影响。综合研究表明,典型剖面硅质岩形成于大洋盆地向大陆边缘台地过渡环境。     

东亚副热带西风急流及其年际变率的海气耦合模式模拟

分析了中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG/IAP)快速耦合气候系统模式FGOALS_gl模拟的东亚副热带西风急流,并讨论了ENSO对东亚夏季副热带西风急流位置的影响.FGOALS_gl能较好模拟东亚副热带西风急流的空间分布以及季节演变,但较之再分析资料,模式模拟的急流强度偏弱...     

基于时空Logistic回归模型的漳州城市扩展预测分析

本文提出一种以时空Logistic回归模型来预测城市扩展的新方法。其首先在传统Logistic回归模型中加入空间自相关结构构建空间Logistic回归模型,然后,利用漳州市区近20年(1989-2009年)的数据,建立不同时期城市扩展模拟的多个子空间Logistic回归模型M1,再采用一次平滑指数法综合处理这些时间序列...     

The flexible global ocean-atmosphere-land system model, Grid-point Version 2: FGOALS-g2

This study mainly introduces the development of the Flexible Global Ocean-Atmosphere-Land System Model: Grid-point Version 2 (FGOALS-g2) and the preliminary evaluations of its performances based on results from the pre-industrial control run and four members of historical runs according to the fifth phase of the Coupled Model Intercomparison Project (CMIP5) experiment design. The results suggest that many obvious improvements have been achieved by the FGOALS-g2 compared with the previous version,FGOALS-g1, including its climatological mean states, climate variability, and 20th century surface temperature evolution. For example,FGOALS-g2 better simulates the frequency of tropical land precipitation, East Asian Monsoon precipitation and its seasonal cycle, MJO and ENSO, which are closely related to the updated cumulus parameterization scheme, as well as the alleviation of uncertainties in some key parameters in shallow and deep convection schemes, cloud fraction, cloud macro/microphysical processes and the boundary layer scheme in its atmospheric model. The annual cycle of sea surface temperature along the equator in the Pacific is significantly improved in the new version. The sea ice salinity simulation is one of the unique characteristics of FGOALS-g2, although it is somehow inconsistent with empirical observations in the Antarctic.     

Relationships between the East Asian-western north pacific monsoon and ENSO simulated by FGOALS-s2

The relationships between ENSO and the East Asian-western North Pacific monsoon simulated by the Flexible Global Ocean-Atmosphere-Land System model, Spectral Version 2 (FGOALS-s2), a state-of-the-art coupled general circulation model (CGCM), are evaluated. For El Nio developing summers, FGOALS-s2 reproduces the anomalous cyclone over the western North Pacific (WNP) and associated negative precipitation anomalies in situ. In the observation, the anomalous cyclone is transformed to an anomalous anticyclone over the WNP (WNPAC) during El Nio mature winters. The model reproduces the WNPAC and associated positive precipitation anomalies over southeastern China during winter. However, the model fails to simulate the asymmetry of the wintertime circulation anomalies over the WNP between El Nio and La Nia. The simulated anomalous cyclone over the WNP (WNPC) associated with La Nia is generally symmetric about the WNPAC associated with El Nio, rather than shifted westward as that in the observation. The discrepancy can partially explain why simulated La Nin a events decay much faster than observed. In the observation, the WNPAC maintains throughout the El Nio decaying summer under the combined effects of local forcing of the WNP cold sea surface temperature anomaly (SSTA) and remote forcing from basinwide warming in the tropical Indian Ocean. FGOALS-s2 captures the two mechanisms and reproduces the WNPAC throughout the summer. However, owing to biases in the mean state, the precipitation anomalies over East Asia, especially those of the Meiyu rain belt, are much weaker than that in the observation.     

基于光谱混合分析的毛乌素沙地油蒿群落覆盖度提取

油蒿群落覆盖度是判断毛乌素沙地荒漠化程度严重与否的直接指标,其信息的准确获取有助于更为合理的荒漠化监测与评价。本研究以Landsat ETM 为数据源,深入探讨了光谱混合分析过程中影像预处理、端元选取、光谱混合模型选择及光谱混合分析结果分析等关键问题,给出了恰当的解决方案,进而进行了油蒿群落覆盖度的提取,并通过野外实测数据对提取结果进行了验证。验证结果表明:基于光谱混合分析技术提取的油蒿群落分量与实测油蒿群落覆盖度线性相关显著,相关系数为0.88,因而研究区的油蒿群落覆盖度可以通过油蒿群落分量的线性变换得到。因此,光谱混合分析是提取毛乌素沙地油蒿群落覆盖度的有效技术。     

黔北务正道地区铝土矿基础地质与成矿作用研究进展

务正道地区铝土矿底板地层黄龙组类化石及铝土矿层大竹园组、梁山组的孢粉化石限定,大竹园组的时代为早二叠世。大竹园组铝土矿的沉积环境为向北半封闭的海湾或海泛湖。铝土矿形成于低纬度热带气候条件下,气候具旱季、雨季之分,盆地水体为弱酸性还原条件,陆地植物生态系统和盆地微生物生态系统对铝土矿的形成起了重要作用。铝土矿的主要物源为志留系韩家店组和石炭系黄龙组双重物源。陆源区风化的铝质通过胶体作用搬运到盆地中形成铝土质岩。铝土矿层形成之后,又经历了多期次暴露地表的风化淋滤。淋滤作用分别在渗流带和潜流带形成土状、半土状铝土矿和致密状铝土矿,盆地内部铝土岩破碎和胶体凝聚分别形成碎屑状、豆鲕状铝土矿。风化过程中多数元素发生了不同程度的丢失,而SiO2的流失程度明显大于Al2O3,从而形成铝土矿矿层。因此,盆地的沉积体系和古地理控制了铝土矿矿系的分布范围和厚度,多期次的淋滤作用控制了铝土矿的品质和矿层的厚度。     

表面设置防火涂料高强混凝土柱的耐火极限

前期试验表明,表面设置厚度20 mm的某非膨胀型防火涂料可较好地抑制高强混凝土的高温爆裂。本文通过试验反算给出了该涂料对应不同温度区间的平均导温系数;随后,利用结构抗火分析软件SAFIR对表面设置该涂料的高强混凝土柱的耐火极限进行了计算分析,考察了截面尺寸、轴压比、荷栽偏心率及配筋率等因素的影响,在此基础上提出了相应的高强混凝土柱耐火极限实用计算公式。研究结果表明：①该涂料的平均导温系数随温度升高有所降低;②表面设置厚度20 mm的该涂料可明显提高高强混凝土柱的耐火极限,提高幅度达40%～350%。