Structure of the Potential Vorticity of an Explosive Cyclone over the Eastern Asian Region in Late November 2013

An explosive extratropical cyclone(EC)over the Eastern Asian region that caused two shipwrecks is analyzed using ERA-Interim reanalysis data from the European Center for Medium-Range Weather Forecasts.Analyses of the evolution of the EC reveal that the positive potential vorticity(PV)at the upper-tropospheric level displays a hook-shaped structure during the mature period of the cyclone.The PV distribution forms a vertically coherent PV structure called a PV tower.The vertical distribution of the PV can induce and strengthen cyclonic circulation from the lower-to upper-levels of troposphere,which is an important deepening mechanism of explosive cyclone.The PV tower occurs approximately ten hours prior to the development of surface occlusion in the cyclone.The evolution of surface fronts closely follows the development of the horizontal upper-tropospheric PV.This tandem development is largely attributed to the ability of the positive upper-tropospheric PV and the PV tower to induce cyclonic circulation simultaneously.The kinematic wrap-up process of cyclonic circulation also accelerates the formation of warm occlusion.A conceptual model of the distributions of positive PV and potential temperature combining the perspectives of dynamic tropopause folding,PV tower,and atmospheric stability,including westward tilting and baroclinicity,is proposed.This model can illustrate the explosive deepening mechanism of ECs.The regions of convective instability and rainfall determined by this model are consistent with those identified from the actual observation.     

Determination of the fault plane using a single near-field seismic station with a finite-dimension source model

We explore the possibility of determining the actual fault plane of an earthquake from the inversion of near-source displacement seismograms of one station when a finite-dimension source is used instead of a point source model and when the complete displacement is taken into account, including near-field waves. Tests on synthetic seismograms and real data recorded at local distances show that this is possible even with a single, three-component station. A single accelerogram available for the Erzincan, Turkey, 1992 March 13, M _s = 6.8 earthquake is inverted and the solution found is compatible with other seismological studies and with the mechanism expected for the North Anatolian Fault.     

Investigation of a Tertiary maar structure using three-dimensional resistivity imaging

This paper presents the application of the electrical resistivity tomography (ERT) method to the investigation of the Tertiary maar structure of Baruth (Germany) known from previous gravimetric surveys. ERT was applied to support the optimum location for a palaeoclimatological drill hole.
  Special modifications of data acquisition, signal processing and inversion are introduced to adapt the method of ERT to the special requirements for the 3-D investigation of structures with horizontal extensions of 1  km or more. More than 5000 dipole–dipole combinations were recorded at three concentric circular electrode arrangements using stand-alone transient data acquisition systems (RefTek).
  We present a fast approximate imaging technique based on the simultaneous iterative reconstruction technique (SIRT). As the complete calculation of the inverse Frechét matrix is avoided, the algorithm is especially suitable for large data and model spaces, where complete inversion is beyond the limits of available computing hardware. The single-step method is applicable to arbitrary irregular electrode layouts. Synthetic tests show that the imaging procedure reconstructs the main features of the subsurface.
  A low-resistivity body could be interpreted as limnic sediments filling the interior of the Tertiary maar crater. Considering the horizontal resistivity gradient, estimates for the lateral and depth extents of the structure were made. An optimum position for a palaeoclimatological borehole was found, and was in good agreement with the gravimetric minimum.     

地下水模型的Neumann展开Monte-Carlo随机有限元法

讨论了求解地下水模型(水流模型和水质模型)的Neumann展开Monte-Carlo随机有限元法。从基本的随机变量入手,避免了过程中随机变量的增多问题,给出结点水头(浓度)的均值、方差和水头在某区间的概率计算方法;改进了矩阵求逆的效率,对输入随机变量较多、随机变量变异较大的非稳定地下水问题特别有效。同时选取二维承压地下水水流问题(有解析解)作为例子,进行了随机数值模拟实验。      

层状介质中含水岩溶的数值模拟

针对用均匀高阻介质中的低阻体来模拟含水岩溶构造的缺陷,用积分方程法对两层介质中的岩溶构造进行了数值模拟,并分析了计算曲线的特征,以及表层、岩溶与围岩的电阻率差异对探测结果的影响。计算结果对野外施工和资料解释具有指导意义。      

物探电法在锦州东港电力有限公司矿泉水水源地勘查的综合应用

锦州东港电力有限公司矿泉水水源地位于辽西中部断陷盆地锦州盆地的北端。地处中新生代上侏罗统及白垩系构成的对称向斜,NNE新华夏系断裂构造经由锦州盆地通过。工作区第四系覆盖6-14m,下伏孙家湾组(K2S)砂质泥岩、砂砾岩和义县组(K1y)火山碎屑岩、英安岩、安山岩及火山凝灰角砾岩。对该区进行地质水文资料综合分析的基础上,采用电阻率联合剖面、高密度电阻率法、电测深(电阻率、衰减时及极化率)多种物探电法综合勘查,确定断裂构造位置、产状及赋水性。经验证获得涌水量312t/d具有商业价值的矿泉水水源地。这一工作方法在辽西火山岩贫水区进行水资源勘查具有推广意义。     

矿井水源判别的模糊数学方法

通过对邢台矿务局五个矿214个水样化学分析资料的统计,给出了利用频数统计法和正态分布型函数形成各因素隶属度的方法,求标准参数值和权重值数学模型及水源快速判别模糊综合评判的数学方法。验证结果证明了这种方法的可行性和可靠性。      

关中活断层和地裂缝的年代学研究

取该区活动断裂中的断层泥,并首次在几个断层面附近的劈理化黄土中取样测出热释光年龄。12个断层热释光年龄数据在20-240ka B P之间变化,证实中更新世晚期和晚更新世期间断层曾有一次活动,为本区断层的活动性提供了证据。本研究成果也为西安地裂缝的活断层与人工抽水双重成因提供了证据。      

黄海潮生陆架锋的数值模拟研究

采用海洋三维热结构及环流模式,模拟了黄海在Ｍ２潮流混合作用下,夏季温度的分布和变化特征。从数值研究的角度,对黄海陆架水域的海洋锋现象,诸如苏北浅滩外、山东半岛东端、大连、木浦水域的锋面以及锋面沿岸一侧的表层冷水区的成因及分布进行了探讨,模拟结果再现了黄海陆架锋的潮生性质。     

一种新型筑堤结构：轻质硬壳堤坝

针对软弱地基存在的堤坝不均匀沉降、滑坡、位移、倒塌等问题,提出了一种新型的筑堤结构──轻质硬壳堤坝。该结构采用发泡塑料作为堤坝材料,或铺设于软基面上,或填充于易沉陷部位,或搅拌于土石方中;以高强度材料,制成堤坝外壳或堤坝某一部分的外壳,然后填入其他松散材料,使其产生减重、加筋、防渗、隔离、堆高的作用,以增强堤坝刚度,提高堤坝稳定性。这种新型堤坝结构具有较高的防洪、抗地震能力,以及缩短建筑工期,降低造价,废物利用等优点。