藏北班公湖-怒江缝合带西段沙木罗组火山岩年代学、Hf同位素及地球化学特征

班公湖-怒江缝合带在中生代的构造岩浆演化一直以来都是青藏高原基础地质研究中的热点之一.在该缝合带南部的冈底斯北部地区发育大量的中生代火山岩及相关岩浆岩,其岩石成因与成岩地球动力学背景长期以来存在较大的争议.以班公湖-怒江缝合带西段阿翁错地区沙木罗组新发现的火山岩夹层为研究对象,对沙木罗组的形成时代、火山岩的成因、构造环...     

银额盆地侏罗纪孢粉植物群的发现及其地层时代意义——以蒙额地1井为例

由于露头资料缺乏,银额盆地生物地层研究一直较为薄弱,钻井的地层时代划分及主要油气产层时代归属存在较大争议。为了厘清银额盆地钻井所揭示的油气产层的地层时代,本研究对位于盆地西部乌珠尔坳陷的蒙额地1井下部岩芯样品开展了孢粉学研究工作。根据孢粉类群及其含量的变化,划分了2个孢粉组合:Osmundacidites-Deltoidospora-nonstriate bisaccate组合和Classopollis-Cyathidites-Quadraeculina组合。第一组合中裸子植物花粉和蕨类植物孢子含量相当,裸子植物花粉中无肋纹的双气囊花粉出现最为频繁,且多样性较高,并零星出现有具肋纹双气囊花粉,蕨类植物孢子以Osmundacidites为主,其他常见类群包括Lycopodiumsporites、Deltoidospora、Neoraistrickia等,均为我国侏罗纪常见属种,孢粉组合指示的地层时代为早侏罗世晚期,也可能下延至早侏罗世中期,气候温暖湿润;第二组合以Classopollis的高含量为特征,Quadraeculina和Cyathidites较第一组合含量增加,且未出现任何白垩...     

Parallelism and optimization of numerical ocean forecasting model

According to the characteristics of Chinese marginal seas, the Marginal Sea Model of China (MSMC) has been developed independently in China. Because the model requires long simulation time, as a routine forecasting model, the parallelism of MSMC becomes necessary to be introduced to improve the performance of it. However, some methods used in MSMC, such as Successive Over Relaxation (SOR) algorithm, are not suitable for parallelism. In this paper, methods are developedto solve the parallel problem of the SOR algorithm following the steps as below. First, based on a 3D computing grid system, an automatic data partition method is implemented to dynamically divide the computing grid according to computing resources. Next, based on the characteristics of the numerical forecasting model, a parallel method is designed to solve the parallel problem of the SOR algorithm. Lastly, a communication optimization method is provided to avoid the cost of communication. In the communication optimization method, the non-blocking communication of Message Passing Interface (MPI) is used to implement the parallelism of MSMC with complex physical equations, and the process of communication is overlapped with the computations for improving the performance of parallel MSMC. The experiments show that the parallel MSMC runs 97.2 times faster than the serial MSMC, and root mean square error between the parallel MSMC and the serial MSMC is less than 0.01 for a 30-day simulation (172800 time steps), which meets the requirements of timeliness and accuracy for numerical ocean forecasting products.     

Long‐term water budget imbalances and error sources for cold region drainage basins

This study assessed the long‐term (1979–2008) water budget closures for 19 large cold region drainage basins in Canada using recently developed datasets for precipitation (P), land surface evapotranspiration and water surface evaporation, and observed streamflow. Total water storage (TWS) trends from the GRACE satellite observations were also used to assist the assessment. The objectives are to quantify the magnitudes and spatial patterns of the water budget imbalance (ε) and its source of errors for these cold region basins. Results showed that the water budget was closed within 10% of the P on average for all the basins. The ε showed a general pattern of positive values in the south and negative values in the north and mountainous regions over the country. Basins with large ε values were mostly found in the north. Uncertainties in the water budget variables, particularly P, were found to play a major role in the ε. Significant trends in TWS were found over 11 basins, which accounted for 31% of their ε on average. Improvements in the observation network, data quality assurance, and spatial models for P are critical for further improving the water budget closure for the cold region drainage basins. © 2014 Her Majesty the Queen in Right of Canada. Hydrological Processes. © John Wiley & Sons, Ltd.     

瞬变电磁法勘探在煤层采空积水区的应用

山西翼城某矿在巷道掘进时,发现煤壁挂汗,巷道渗水等现象,疑为采空破坏区。为查明勘探区内是否存在采空破坏区及导水断层、陷落柱等构造,圈定煤层积水区及其范围,对该区进行了瞬变电磁法勘探。数据采集使用美国ZONGE公司的GDP-32II电法仪器,采用大定源中心回线方法施工测线11条,经资料处理和解释,在勘探区内没有发现较大的断层和陷落柱,仅在勘探区西南角一处推断存在采空区(积水),另外圈出3处富含水区,3处含水区。该勘探成果为解决矿井建设和开采中的地质难题,提供了可靠的地质信息。     

Groundwater storage variability and annual recharge using well-hydrograph and GRACE satellite data

Most studies using GRACE (Gravity Recovery and Climate Experiment) data for examining water storage anomalies have rich hydrogeological databases. Here, GRACE data are analyzed for southern Mali, Africa, a region with sparse hydrogeological data. GRACE data (2002?C2008) did not overlap with observed groundwater-level data (1982?C2002). Terrestrial water storage from GRACE was corrected for soil moisture using the Global Land Data Assimilation System (GLDAS) model to obtain monthly groundwater storage anomalies and annual net recharge. Historical storage anomalies and net recharge were determined using the water-table fluctuation method for available observation wells. Average annual net recharge averaged 149.1?mm (or 16.4% of annual rainfall) and 149.7?mm (14.8%) from historical water level and GRACE data, respectively. Monthly storage anomaly lows and peaks were observed in May and September, respectively, but have a shift in peak to November using the corrected GRACE data, suggesting that the GLDAS model may poorly predict the timing of soil-water storage in this region. Notwithstanding problems with the GLDAS model, the soil moisture-corrected GRACE data accurately predict the relative timing and magnitude of groundwater-storage changes, suggesting that GRACE data are valuable for identifying long-term regional changes in groundwater storage in areas with sparse hydrogeological data.     

海岛礁成图编绘系统的研究与实现

我国《测绘法》规定:陆域测绘即多年平均高潮位线之上的基础测绘由地方行政负责;海洋测绘即低潮位线以下的基础测绘由海军负责.两线之间的潮间带法律没有明确管辖属性,而海岛(礁)测绘关联此域.以编绘系统为线索,介绍该域高、低潮面测绘成果的转换关系,以及如何使数字图能满足出版要求,符合GIS入库、显示、分析的数据格式.     

文登市农村集体建设用地情况的调查

2006年12月至2007年4月，文登市国土资源局结合国土资源部、世界银行“农村集体建设用地管理利用政策研究”项目，从农村集体建设用地流转、农民宅基地管理、小城镇建设用地以及农村集体建设用地整理等4个方面人手，对农村集体建设用地管理开展全面调查。并对调查结果进行了分析研究，提出了文登市农村集体建设用地管理利用的思路。     

Estimating stratal completeness of carbonate deposition via process-based stratigraphic forward modeling

Hiatuses are ubiquitous in stratigraphic records at various temporal scales,but they cannot be easily identified and quantified owing to the lack of adequate methods in determining the duration of hiatuses or stratal completeness.Here a processbased stratigraphic forward modeling(SFM)approach was used to effectively estimate the completeness of carbonate strata in three dimensions and at basin-scale.By using information derived from both spatial and temporal domains in the SFM outputs for five grid locations(pseudo wells)under different depositional settings,we were able to delineate basin-wide hiatuses of various temporal scales and determine their durations and stratal completeness quantitatively.The stratal completeness appears to be controlled by sea level changes,depositional environments,carbonate growth rates and tectonic subsidence patterns in various ways.     

基于监视相机单像量测的嫦娥三号巡视器与着陆器分离决策支持

嫦娥三号探测器系统两器分离是着陆后进行的第一个关键动作,也是后续着陆器探测和巡视器月面巡视勘察的基础,解决两器安全分离问题对于整个工程的实施具有重要意义。针对实际任务中对分离决策实时性和可靠性要求高的特点,使用基于着陆器监视相机的单像量测方法对月面环境中障碍物和通信遮挡包络进行分析计算,评估两器分离过程中的不安全因素,为两器分离决策提供支持。介绍了监视相机单像量测和通信遮挡包络计算方法,并对量测精度进行了分析验证。