基于双差观测序列曲线拟合实现GPS静态定位基线实时解算

对于ＧＰＳ静态差分定位的实时算法而言,能否实时地解决观测数据的存储、卫星失锁、载波相位周跳、多径效应以及计算速度等问题是保证基线的实时解算和定位成功率的重要因素。本文利用载波相位双差观测时间序列可用直线或高次曲线进行很好拟合的特性,设计了一种静态定位的实时算法,能解决上述实时定位中的特殊问题。     

鞍山地区陈台沟壳岩时代归属的初步研究

鞍山市东部约8km处的陈台沟村附近,出露一套以斜长角闪岩类、石英岩类和长英质片麻岩类组成的表壳岩。长期以来，大多数地质学者一直将该表壳岩划归为鞍山群，但在岩石组合、变质变形特征和含矿性等诸多方面，都与鞍山地区公认的鞍山群明显不同，因表壳岩本身缺少准确定年的对象，难以直接测年，笔者将侵入于长英质片麻岩中的花岗岩脉中的锆石颗粒，用Kober方法和离子探针质谱计（SHRIMP）测定年龄，取得了表壳岩的沉积年龄为3376±5Ma-3357±4Ma。说明该表壳岩形成时代远老于鞍山群。     

热带副热带高度异常对长江流域和华北旱涝影响的数值模拟与分析

前期南亚高压的异常增强或者减弱,热带、副热带地区100 hPa高度的异常增高或者降低,热带西风的异常增强或者减弱,对长江流域和华北地区夏季的降水异常具有预示作用。文中设计了一系列的数值试验进行模拟研究,包括控制试验、敏感试验和4组合成试验。合成试验模拟结果表明,前期热带、副热带高度异常分布,能够再现长江流域、华北旱涝情况。前期南亚高压、热带、副热带高度、风异常对长江流域和华北地区夏季降水的异常均有预示作用。100 hPa叠加高度、风异常的敏感试验结果表明:前期南亚高压、热带与副热带地区100 hPa高度场和环流场的异常不仅可以预示、事实上能够引起长江流域和华北夏季降水的异常———前期南亚高压异常增强、热带、副热带地区100 hPa高度场异常增高、西风异常增强,易引起长江流域降水偏多、华北降水偏少;反之,则容易引起长江流域降水偏少、华北降水偏多。     

GCITEM-IGGCAS: A new global coupled ionosphere–thermosphere-electrodynamics model

The Global Coupled Ionosphere–Thermosphere-Electrodynamics Model developed at Institute of Geology and Geophysics, Chinese Academy of Sciences (GCITEM-IGGCAS), is introduced in this paper. This new model self-consistently calculates the time-dependent three-dimensional (3-D) structures of the main thermospheric and ionospheric parameters in the height range from 90 to 600 km, including neutral number density of major species O₂, N₂, and O and minor species N(²D), N(⁴S), NO, He and Ar; ion number densities of O⁺ ,O₂⁺, N₂⁺, NO⁺, N⁺ and electron; neutral, electron and ion temperature; and neutral wind vectors. The mid- and low-latitude electric fields can also be self-consistently calculated. GCITEM-IGGCAS is a full 3-D code with 5° latitude by 7.5° longitude cells in a spherical geographical coordinate system, which bases on an altitude grid. We show two simulations in this paper: a March Equinox one and a June Solstice one, and compare their simulation results to MSIS00 and IRI2000 empirical model. GCITEM-IGGCAS can reproduce the main features of the thermosphere and ionosphere in both cases.     

用雷达反射率作对流性降水和层状云降水自动分类

为提高雷达定量测量降水的精度,利用武汉CINRAD/SA雷达反射率数据,研究提出了对流性降水和层状云降水自动分类算法(ACSS)。该算法在二维反射率结构场初步分类降水的基础上,识别亮带并从体扫描数据中提取降水的三维结构特征,然后对初步分类结果进行订正。试验表明,ACSS能较准确地实现对流性降水和层状云降水的自动分类,相对于只根据二维结构分类降水性能上有较大提高,主要表现在能正确识别出亮带特征明显的强层状云和对流核外沿的对流弱回波区。     

核磁共振找水方法在河南某地区的试验结果

利用核磁共振技术直接找水是一种新方法。本文论述该方法的原理、仪器装备,并以NUMIS系统在河南某地试验结果为例,说明本方法找水的有效性。     

潮汐水位振幅和位相变化研究及其在地下水异常分析中的应用

将多孔介质中井-含水层-隔水层的潮汐水位振幅和位相的计算公式推广到裂隙饱水岩体潮汐分析中, 分析了裂隙含水层中井与裂隙, 裂隙与微裂隙的潮汐孔压响应原理和水流交换过程, 提取了影响裂隙含水层潮汐水位振幅和位相的主要因素, 应用井-裂隙排水产生的井水位-引潮高的振幅比A和位相差α₂主要随径向等效导水系数T同向变化, 裂隙和微裂隙(孔隙)排水产生的孔压-引潮高的振幅比D和位相差α₁主要随不排水条件下微裂隙与裂隙间振幅比E'/E反向变化的规律, 提出了潮汐井水位振幅和位相的8种不同变化类型, 分析了不同类型所反映的含水层形变, 并用于分析东川、 弥勒和西昌川03等3口井井水位振幅和位相变化的成因.     

A knowledge-driven GIS modeling technique for groundwater potential mapping at the Upper Langat Basin, Malaysia

The aim of this paper is to use a knowledge-driven expert-based geographical information system (GIS) model coupling with remote-sensing-derived parameters for groundwater potential mapping in an area of the Upper Langat Basin, Malaysia. In this study, nine groundwater storage controlling parameters that affect groundwater occurrences are derived from remotely sensed imagery, available maps, and associated databases. Those parameters are: lithology, slope, lineament, land use, soil, rainfall, drainage density, elevation, and geomorphology. Then the parameter layers were integrated and modeled using a knowledge-driven GIS of weighted linear combination. The weightage and score for each parameter and their classes are based on the Malaysian groundwater expert opinion survey. The predicted groundwater potential map was classified into four distinct zones based on the classification scheme designed by Department of Minerals and Geoscience Malaysia (JMG). The results showed that about 17% of the study area falls under low-potential zone, with 66% on moderate-potential zone, 15% with high-potential zone, and only 0.45% falls under very-high-potential zone. The results obtained in this study were validated with the groundwater borehole wells data compiled by the JMG and showed 76% of prediction accuracy. In addition statistical analysis indicated that hard rock dominant of the study area is controlled by secondary porosity such as distance from lineament and density of lineament. There are high correlations between area percentage of predicted groundwater potential zones and groundwater well yield. Results obtained from this study can be useful for future planning of groundwater exploration, planning and development by related agencies in Malaysia which provide a rapid method and reduce cost as well as less time consuming. The results may be also transferable to other areas of similar hydrological characteristics.     

Geochemistry of rare earth elements in the mid-late Quaternary sediments of the western Philippine Sea and their paleoenvironmental significance

Based on a δ18O chronology,rare earth elements(REE) and other typical elements in sediments from core MD06-3047 in the western Philippine Sea were analyzed to constrain the provenances of the sediments and investigate quantitative changes in the Asian eolian input to the study area over the last 700 ka.Among the competing processes that might affect REE compositions,sediment provenance is the most important one.Provenance analysis suggests that the study sediments have two provenance end-members;local volcanic sources are dominant,and eolian dust from the Asian continent has a smaller contribution.During glacial periods,eolian input to the western Philippine Sea was enhanced.In contrast,material supply from local volcanics increased during interglacial periods.Changes in eolian input to the study area were probably related to the strength of the East Asian winter monsoon(EAWM) as well as aridity in the Asian continent on an orbital time scale,and were partly influenced by local control factors on shorter time scales.Therefore,we propose that the present study expands the application of the REE-based method for quantitatively estimating the eolian component from the mid-latitude northern Pacific to the low-latitude western Pacific.Additionally,the study preliminarily confirms the influence of EAWM-transported eolian material on sedimentation in the western Philippine Sea since 700 ka.     

边界层辐合线对强对流系统形成和发展的作用

应用天津CINRAD/SA雷达探测到的边界层辐合线信息,对2008—2009年6—9月发生在天津地区的边界层辐合线进行了统计分析,与2002—2007年海风锋触发形成的局地强对流天气分析相结合,研究结果表明:天津地区边界层辐合线的雷达低仰角基本反射率因子产品的回波特征一般表现为弱的窄带回波,回波强度仅为15~25 dBZ,宽度一般为3~10 km。在合适的层结状态和水汽条件下,这些边界层辐合线的演变和碰撞与强对流天气的发生、发展密切相关。单一边界层辐合线一般不能形成大范围的雷暴天气;两条以上边界层辐合线之间碰撞,一般在碰撞交叉处能够形成强对流天气。若已存在强对流天气,则强对流天气将加强。