洋山深水港区海域秋、冬季沉积物中重金属来源分析及生态风险评价(英文)

通过测定洋山深水港区海域2010~2013年6个航次秋、冬季沉积物中重金属含量,分析其时空差异,结果表明该海域沉积物重金属总体含量较低,空间分布较为均匀,Hg、Zn、Pb、Cd含量秋季明显高于冬季,As、Cu含量的季节性波动较小,用因子分析法研究该海域重金属来源,发现陆源工业、船舶航运排污以及有机质降解是研究海域Pb、Cd、Zn的主要来源;农业污染、码头货物装卸残留及建筑垃圾支配着Cu、As、Hg的来源。SQG-Q生态风险评价表明研究海域沉积物中重金属均存在中、低度的生态风险,秋季的生态风险高于冬季,Hg和Cu是主要生态风险因子;地累积指数法评价结果显示研究海域基本不受Hg、As、Zn、Pb的污染;Cd、Cu以轻度污染为主,部分站位属于偏中度污染,6种重金属污染程度依次为:CdCuPbZnHgAs。因子综合得分评价表明,重金属污染相对严重的站位依次为5号、4号及3号站位。但总体看来洋山深水港区附近海域沉积物中重金属污染状况属于轻度污染。     

PV-based wave-activity density and its application to tracing heavy precipitation

This paper is focused on the tracking of heavy precipitation by detecting strong wave activities in precipitating atmosphere. Based on the generalized moist potential vorticity (GMPV), a new wave-activity density and its wave-activity relation are first derived. The wave-activity density, which is the second-order portion of GMPV and quadratic in disturbance, is then applied to a heavy-rainfall event in North China. It is shown that the wave-activity density contains the vertical shear of wind perturbation, vertical vorticity perturbation and the spatial gradients of latent heating function perturbation associated with the moisture condensation. Due to these important characteristics of precipitating atmosphere, the wave-activity density shows strong anomalies over the precipitation region. The total GMPV and its basic-state and first-order components are also analyzed as comparisons. The result shows that the basic-state GMPV is not capable of diagnosing precipitation, while the total GMPV and the first-order GMPV, although present strong anomalies, are not capable of distinguishing precipitation and non-precipitation areas. This is likely due to the basic state information contained in GMPV and its basic-state and first-order components, which has no direct relation to the precipitation. The spatial distribution of wave-activity density further verifies its capability on detecting and tracing heavy precipitation. Moreover, the statistical result reveals the wave-activity density has a high correlation coefficient with the observational rainfall in a long time series and passes through the significance test.     

Impact of vegetation feedback on the mid-Pliocene warm climate

Studying the vegetation feedback during warm periods of the past can lead to better understanding of those in the future.In this study,we conducted several simulations to analyze vegetation feedback during the mid-Pliocene warm period.The results indicate that the main features of vegetation change in the mid-Pliocene were a northward shift of needleleaf tree,an expansion of broadleaf tree and shrub,and a northward expansion of grass,as compared to the pre-industrial period.The global annual mean warming ratio caused by vegetation feedback was 12.1％,and this warming ratio was much larger in northern middle and high latitudes.The warming caused by vegetation change was directly related to the surface albedo change and was further amplified by snow/sea ice-albedo feedback.     

基于手势动作识别的地图浏览

针对当前热门的体感技术,研究基于手势动作识别的地图浏览方式。通过Microsoft Kinect手势的设计与识别,与搭建的OpenLayers等地图平台的浏览操作对接,实现基于人体自定义动作对地图浏览的操作,这种更人性化的人机交互方式在解放电脑对人的束缚的同时,也更促进了人机交互的融合。     

基于全球MGEX数据的北斗导航星座精密轨道确定

利用全球分布的MGEX站观测数据,使用"两步法"以双差方式对北斗卫星进行精密定轨。主要研究北斗卫星轨道确定的处理策略,重点分析轨道确定的流程,并通过实验评价了3种不同类型轨道的精度。结果显示,MEO和IGSO卫星的定轨内符合精度优于0.2m,其中径向优于10cm,外符合精度优于30cm;GEO(以C05号为例)卫星外符合精度优于0.7m,且径向优于10cm。     

Impact of the Kuroshio Current on the South China Sea based on a 115 000 year diatom record

We used the tropical oceanic planktonic diatom species Nitzschia marina, Rhizosolenia bergonii and Azpeitia africana/Azpeitia neocrenulata, most commonly found in the surface sediments of the northeasternmost South China Sea (SCS) where the Kuroshio Current enters the SCS through the Bashi Strait north of Luzon, to analyse the influence of the the Kuroshio Current on the SCS. The impact of the Kuroshio Current seems to be relatively strong during major warm periods and, to a lesser degree, in minor warm periods during the last 115 000 years. The strongest influence took place during the main part of the Holocene and during the very late phase of Marine Isotope Stage (MIS) 5e. It is possible to distinguish two magnitudes of change in the impact of the Kuroshio Current on the SCS: large changes occurred at shifts between glacial and interglacial conditions, while smaller changes seem to have recurred in both glacial and interglacial episodes as well as during the Holocene. Climatic/oceanographic changes and sea‐level variations were possibly the two most important mechanisms for the varying influences of the Kuroshio Current on the SCS. The interaction between the Kuroshio Current and monsoon‐related processes may also have played a role. However, because of restricted knowledge of the present‐day Kuroshio Current and the absence of a modern analogue to the ancient SCS due to the marked changes in palaeogeography, this relationship is difficult to establish. Copyright © 2006 John Wiley & Sons, Ltd.     

Statistically optimal estimation of Greenland Ice Sheet mass variations from GRACE monthly solutions using an improved mascon approach

We present an improved mascon approach to transform monthly spherical harmonic solutions based on GRACE satellite data into mass anomaly estimates in Greenland. The GRACE-based spherical harmonic coefficients are used to synthesize gravity anomalies at satellite altitude, which are then inverted into mass anomalies per mascon. The limited spectral content of the gravity anomalies is properly accounted for by applying a low-pass filter as part of the inversion procedure to make the functional model spectrally consistent with the data. The full error covariance matrices of the monthly GRACE solutions are properly propagated using the law of covariance propagation. Using numerical experiments, we demonstrate the importance of a proper data weighting and of the spectral consistency between functional model and data. The developed methodology is applied to process real GRACE level-2 data (CSR RL05). The obtained mass anomaly estimates are integrated over five drainage systems, as well as over entire Greenland. We find that the statistically optimal data weighting reduces random noise by 35–69%, depending on the drainage system. The obtained mass anomaly time-series are de-trended to eliminate the contribution of ice discharge and are compared with de-trended surface mass balance (SMB) time-series computed with the Regional Atmospheric Climate Model (RACMO 2.3). We show that when using a statistically optimal data weighting in GRACE data processing, the discrepancies between GRACE-based estimates of SMB and modelled SMB are reduced by 24–47%.     

冀中坳陷奥陶系潜山油气藏形成条件与成藏模式

冀中坳陷潜山是增储上产的重要领域,奥陶系潜山由于储层非均质性强、控藏因素复杂,因此一直制约着油气勘探的新发现。基于大量岩心、薄片、测井、地震及地球化学数据和地质分析的基础上,对其成藏条件及成藏模式进行了系统分析,指导杨税务潜山、文安斜坡潜山勘探取得重要突破。研究表明：冀中坳陷发育古近系沙三段和沙四段以及上古生界石炭—二叠系3套烃源岩,为潜山油气藏的形成提供了充足的物质基础;明确了碳酸盐岩“云化-岩溶-断裂”三主因叠合控储机理,建立了岩溶孔洞型、断裂孔缝型和云岩孔隙型3种储层模式,拓展了勘探空间;受印支期、燕山期、喜山期多期构造作用叠加控制,形成了先隆后凹型和先凹后隆型两种成因潜山圈闭类型。通过奥陶系潜山成藏要素分析,总结出3种潜山油气成藏模式：低位构造-岩性复合准层状潜山成藏模式、中位古储古堵块状潜山成藏模式和高位古储新堵块状潜山成藏模式。综合评价,目前冀中坳陷北部低位构造-岩性复合准层状潜山成藏条件最为有利,泗村店潜山和新镇潜山是下一步勘探的有利方向。     

略论海陆成矿问题

地壳通过不均一性分异形成大陆型地壳和大洋型地壳, 陆核及地块的形成、大陆裂解与增生、洋壳的新生与消减、陆-陆碰撞拼接形成具有不同构造特征的海陆构造区。中国海陆构造演化经历了太古宙陆核形成、元古宙陆块形成、震旦纪至三叠纪联合大陆形成、中新生代联合大陆解体4个阶段, 形成北方(准噶尔—大兴安岭)、北部(塔里木—华北)、南部(扬子—华南)、南方(冈底斯—喜马拉雅), 东部(滨西太平洋)5个大陆及陆缘构造区。太古宙花岗绿岩带、元古宙裂谷(裂陷)带、显生宙大陆边缘是最重要的海陆成矿环境。海陆成矿有利因素的耦合对成矿至关重要, 而最佳耦合的机制及其发生在海陆构造区的时空位置是圈定有利成矿靶区、引导找矿突破的关键科学问题。     

新疆及邻区体波震级初步分析研究

依据《地震震级的规定（GB 17740—2017）》,分析了2009—2017年新疆地震台网所记录的新疆及邻区476次中深源地震事件,测定了13601个m_b（短周期体波震级）和12035个m_B（BB）（宽频带体波震级）的数据样本,回归分析m_b和m_B（BB）得到回归方程及量规函数,结果显示m_b和m_B（BB）相关系数为0.966,表明两者显著相关。因此,建议对于中强型中深源地震可以直接从原始速度型宽频带数字地震记录上测定长周期体波震级m_B（BB）,提高地震速报测定的速度和精度。通过震级偏差统计和台站场地响应计算,分析新疆地震台网中的XKR、HTA、ATS和KSZ等地震台站震级偏差较大的原因为砂岩、灰岩、砂土层等类型的台基放大了场地响应,说明台基类型对体波震级偏差的影响较大。与NEIC测定的体波震级对比时,发现新疆地震台网测定体波震级平均偏大0.42级,且偏差随着震源深度的增加有增大的趋势。