Ore-Bearing Formations of the Precambrian in South China and Their Prospects

In the Precambrian System of the Yangtze and Cathaysian plates six ore-bearing formations can be identified: the Cu-Pb-Zn-bearing formations in volcanic rocks of marine facies of the Neoarchean-Paleoproterozoic, Cu-Au-bearing formations and Pb-Zn-bearing formations in volcanic rocks of marine facies of the Mesoproterozoic, Pb-Zn-bearing formations in volcaniclastic rock and carbonate rock of the Neoproterozoic, Fe-Mn-bearing formations in the volcaniclastic rock of the Neoproterozoic, and Ni-Cr-serpentine-bearing formations in ophiolite and ultrabasic rock of the Meso- and Neoproterozoic. They were mostly formed in the marginal rift valleys of the Yangtze and Cathaysian plates, where occur stratabound and stratiform ore deposits, thermal deposits and porphyry polymetallic deposits. The six regions with ore-bearing formations have good prospects for ore deposits.     

珠江口盆地惠州地区珠江组砂体上倾尖灭的地质-地球物理“逐级预测”方法

砂体上倾尖灭油气藏是岩性油气藏中重要类型之一,砂体上倾尖灭的刻画与描述是上倾尖灭圈闭有效性评价的关键。在以三角洲前缘沉积为主构成的三级层序内,三角洲沉积相关砂体上倾尖灭的地质-地球物理“逐级预测”描述方法对于认识上倾尖灭油气藏分布规律及其油气勘探具有重要意义。该方法由5个部分组成:在三级层序识别的基础上,运用高精度层序地层划分技术建立了四级层序构成的高频层序地层格架;在高频层序约束下,利用地震沉积学技术描述沉积相的平面分布;在地质模型指导下,利用频谱成像技术定性确定尖灭带的分布;利用相控储层反演半定量、定量预测砂体尖灭线;根据不同成因砂体的沉积特点,利用正演模拟技术开展尖灭线的外推预测。     

Climate change and global cycling of persistent organic pollutants: A critical review

Climate warming, one of the main features of global change, has exerted indelible impacts on the environment, among which the impact on the transport and fate of pollutants has aroused widespread concern. Persistent organic pollutants (POPs) are a class of pollutants that are transported worldwide. Determining the impact of climate warming on the global cycling of POPs is important for understanding POP cycling processes and formulating relevant environmental policies. In this review, the main research findings in this field over the past ten years are summarized and the effects of climate warming on emissions, transport, storage, degradation and toxicity of POPs are reviewed. This review also summarizes the primary POP fate models and their application. Additionally, research gaps and future research directions are identified and suggested. Under the influence of climate change, global cycling of POPs mainly shows the following responses. (1) Global warming directly promotes the secondary emission of POPs; for example, temperature rise will cause POPs to be re-released from soils and oceans, and melting glaciers and permafrost can re-release POPs into freshwater ecosystems. (2) Global extreme weather events, such as droughts and floods, result in the redistribution of POPs through intense soil erosion. (3) The changes in atmospheric circulation and ocean currents have significantly influenced the global transport of POPs. (4) Climate warming has altered marine biological productivity, which has changed the POP storage capacity of the ocean. (5) Aquatic and terrestrial food-chain structures have undergone significant changes, which could lead to amplification of POP toxicity in ecosystems. (6) Overall, warming accelerates the POP volatilization process and increases the amount of POPs in the environment, although global warming facilitates their degradation at the same time. (7) Various models have predicted the future environmental behaviors of POPs. These models are used to assist governments in comprehensively considering the impact of global warming on the environmental fate of POPs and therefore controlling POPs effectively. Future studies should focus on the synergistic effects of global changes on the cycling of POPs. Additionally, the interactions among global carbon cycling, water cycling and POP cycling will be a new research direction for better understanding the adaptation of ecosystems to climate change.     

纹理主方向的遥感影像居民地提取

本文研究利用基于傅立叶变换和Hough变换的灰度共生矩阵方法对遥感影像居民地进行提取。首先,通过傅立叶变换把遥感影像变换到频率域,然后利用Hough变换找出遥感影像的主纹理方向,进而把影像主纹理方向旋转至水平,最后利用灰度共生矩阵方法进行纹理分割。实验结果表明:基于傅立叶变换和Hough变换的灰度共生矩阵方法对遥感影像居民地有较好的提取结果。     

The four dimensional variational data assimilation with multiple regularization parameters as a weak constraint (Tikh-4D-Var) and its preliminary application on typhoon initialization

Traditional variational data assimilation (VDA) with only one regularization parameter constraint cannot produce optimal error tuning for all observations. In this paper, a new data assimilation method of “four dimensional variational data assimilation (4D-Var) with multiple regularization parameters as a weak constraint (Tikh-4D-Var)” is proposed by imposing different regularization parameters for different observations. Meanwhile, a new multiple regularization parameters selection method, which is suitable for actual high-dimensional data assimilation system, is proposed based on the posterior information of 4D-Var system. Compared with the traditional single regularization parameter selection method, computation of the proposed multiple regularization parameters selection method is smaller. Based on WRF3.3.1 4D-Var data assimilation system, initialization and simulation of typhoon Chaba (2010) with the new Tikh-4D-Var method are compared with its counterpart 4D-Var to demonstrate the effectiveness of the new method. Results show that the new Tikh-4D-Var method can accelerate the convergence with less iterations. Moreover, compared with 4D-Var method, the typhoon track, intensity (including center surface pressure and maximum wind speed) and structure prediction are obviously improved with Tikh-4D-Var method for 72-h prediction. In addition, the accuracy of the observation error variances can be reflected by the multiple regularization parameters.     

上海城市天际线与高层建筑发展之关系分析

以上海市2000年中心城区航空影像为基础,基于GIS技术分析城市高层建筑与天际线的分布特点及其影响机制。认为城市天际线与高层建筑相互制约,高层建筑的发展与布局必须考虑城市天际线的特色。     

火星冲日对黄河流域大地震的影响

依据行星对应区理论模型,以1900—2014年期间我国黄河流域发生的31个7级以上大地震为例,计算了对应年份的火星视位置、冲日位置以及月球回归赤纬,研究了火星视位置、冲日位置对大地震的影响规律。结果表明:(1)在月球回归赤纬角的天文背景下,火星冲日是触发大地震的第2个主要天文因子,黄河流域大地震受火星冲日位置的影响很明显;(2)火星视赤纬介于20°~22°之间时,是黄河流域的无震期,特别是在该视位置范围内冲日时,黄河流域不会发生大震;(3)火星在其它流域冲日时,如果月球回归赤纬也不对应黄河流域,则该流域将会发生大地震。诸天文因子共同作用,构成了某流域是否发生大震的先决条件。     

Fast and dynamic generation of linear octrees for geological bodies under hardware acceleration

In the application of 3D Geoscience Modeling,we often need to generate the volumetric representations of geological bodies from their surface representations.Linear octree,as an efficient and easily operated volumetric model,is widely used in 3D Geoscience Modeling.This paper proposes an algorithm for fast and dynamic generation of linear octrees of geological bodies from their surface models under hardware acceleration.The Z-buffers are used to determine the attributes of octants and voxels in a fast way,a...