The Global Distribution of Diapycnal Mixing and Mixing Coefficient Tensor in the Upper 2000m Ocean from Argo Observations

Diapycnal Mixing (DM) within the upper 2000m of the global ocean is calculated by a fine-scale parameterization using the multiyear-mean density gridded product that created by employing all the Argo float observations to date through the recently published equation of seawater TEOS-10. The geographic distribution of Argo-derived DM derived in this study is spatial-dependent and varies with latitude and depth. The magnitude and pattern of DM is favorably validated by comparisons with previous studies. Furthermore, the mixing coefficient tensor K is calculated and analyzed. Components of the tensor fitting for the geopotential coordinate models are also presented. It is found that the tensor components in horizontal direction, K_xx and K_yy, have similar magnitude and distribution pattern. In the vertical, K_zz is enhanced over regions with rough topography and strong wind (e.g., Westerly region), suggesting agreement with previous estimates. This work presents a scheme to estimate the DM and mixing coefficient tensor using Argo observations, and offers a useful Argo-based mixing product for the purpose of promoting the study and modeling of ocean circulation and other processes.     

Analytical Theory for One-Dimensional Consolidation of Soil Induced by Time-Dependent Pumping and Loading

Analytical solutions are derived for one-dimensional consolidation induced by time-dependent pumping and loading, in which both the effects of different pumping types and loading conditions are considered, i.e., step pumping, cyclic pumping, constant loading, and step loading. Based on the solutions obtained, some diagrams are prepared and the relevant consolidation behavior of soil is discussed in detail. It has been shown that the consolidation behavior is greatly influenced by pumping velocity, loading pressure, pumping and loading type.     

基于潜标测量的海洋环境噪声谱特性分析

利用海洋环境噪声测量潜标系统对南海典型海域开展了为期3个月的海洋环境噪声测量,16通道海洋环境噪声测量系统每小时测量两分钟噪声信号。数据处理结果表明,800~5 000Hz范围内,噪声谱与风速相关性最好,且风速越大相关性越好,噪声谱与风速的相关性好于与浪高的相关性。风关噪声谱级在海水中部基本不随接收深度发生变化,但由于测量水听器阵长度未能覆盖整个水深,因此未给出海面和海底处谱级变化规律。在400Hz以上的高频段整个风速范围内噪声谱级都随风速发生变化,且噪声谱级与对数风速具有很好的线性关系。     

海底峡谷水动力系统研究

海底峡谷作为海洋中油气勘探的重要指示器和富集场所,研究其复杂的水动力系统变得十分重要。海底峡谷中水动力系统包括了重力流、浊流、潮汐/内潮汐、内波、底层流、上升流和高密度陆架瀑布流(Dense Shelf Water Cascading)等要素,与峡谷外有明显的不同。首次从海底峡谷水动力系统的综合概况出发,研究了水动力作用对峡谷的侵蚀、沉积物的搬运与沉积以及特殊生态系统的塑造,总结分析了峡谷中水动力系统的主要研究手段。结果表明,海底峡谷中的水动力作用由于成因不同,各自的表现特征也不一样;重力流、内潮汐、上升流等水动力作用对峡谷的形态地貌、物质搬运以及生态系统的影响较为显著;对于常用的4种水动力系统的研究方法而言,其研究背景各不相同,且存在一定的局限性。本文为我国海底峡谷水动力系统的研究起到了一定的指导作用。     

永清MS 4.3地震前永清井水温异常分析

2017年12月永清井观测温度急剧下降,采用该井水温、水位多年观测数据,从仪器测量原理及精细温度梯度测量出发,结合井孔资料,认为该变化为永清M_S 4.3地震（井震距<30 km）发生前的异常信息。利用正弦累加模型计算温度异常持续时间和幅度,发现该异常变化存在2个周期：①周期42天,温度变化幅度为0.042 12℃;②周期16.77天,温度变化幅度为0.018 62℃。分析认为,区域应力状态发生变化,使含水层渗透性受到影响,从而间接影响到井下温度传感器安放处水温。地震发生后近距离观测到水温异常变化尚属首次,利用模型对变化时间与幅度进行量化提取,可为经验预报、统计预报提供经典震例。     

Characterization of rocking shallow foundations using centrifuge model tests

This paper presents new results of centrifuge model tests exploring the behavior of rocking shallow foundations embedded in dry sand, which provides a variety of factors of safety for vertical bearing. The results of slow (quasi‐static) cyclic tests of rocking shear walls and dynamic shaking tests of single‐column rocking bridge models are presented. The moment–rotation and settlement–rotation relationships of rocking footings are investigated. Concrete pads were placed in the ground soil to support some models with the objective of reducing the settlement induced by rocking. The behavior of rocking foundation was shown to be sensitive to the geometric factor of safety with respect to bearing failure, L_f/L_c, where L_f was the footing length, and the L_c was the critical soil‐footing contact length that would be required to support pure axial loading. Settlements were shown to be small if L_f/L_c was reasonably large. Placement of concrete pads under the edges of the footing was shown to be a promising approach to reduce settlements resulting from rocking, if settlements were deemed to be excessive and also had impacts on the energy dissipation and rocking moment capacity. A general discussion of the tradeoffs between energy dissipation and re‐centering of rocking foundations and other devices is included. Copyright © 2011 John Wiley & Sons, Ltd.     

基于虚拟SAN的网格GIS数据存储技术研究

针对空间数据存储的特点,结合网格和虚拟SAN技术的优势,提出了基于虚拟SAN的网格GIS数据存储解决方案,旨在解决网格GIS环境下的数据存储问题。     

Effects of Mudstone Particle Content on Shear Strength of a Crushed Sandstone–Mudstone Particle Mixture

The present study focuses on the shear strength, deformation, and particle crushing of sand which is mixed by crushed sandstone and mudstone particles. Two triaxial tests—one for unsaturated specimens and the other for saturated specimens—were performed, along with sieve analysis tests. Results obtained from the triaxial tests indicate that, with the increment of the mudstone particle content by weight, the angle of internal friction decreases, the cohesion increases and then decreases, and both the initial angle of shearing resistance at the atmospheric pressure and decremental angle increase and then decrease. Compared to the unsaturated specimens, the deviator stress or normalized deviator stress of the saturated specimens at the same axial stress may decrease due to the wetting action. Thus, the shear strength of the tested materials may be reduced by the wetting action. Results of sieve analysis tests indicate that the mixing of some mudstone particles into the sandstone particle mixture may reduce the amount of particle crushing, but the wetting action may increase the amount. The amount of the crushed particle may arrive at a minimum of 40% of mudstone particle content by weight.     

测震台网监测能力的评价研究及其在西北四省(区)台网建设中的应用

本文详细地研究了陕、甘、宁、青四省(区)测震台网的监测能力,並给出了台网对不同震级的地震的监测能力图,为研究人员选取震级下限提供了依据。本文还提出了对四省(区)台站的调整的建议。     

贵州遵义深溪大型锰矿床主要地质特征

贵州遵义地区是我国二叠纪锰矿的重要分布区之一,深溪锰矿是遵义地区继铜锣井锰矿发现的第二个大型隐伏锰矿床。本文结合深溪锰矿找矿实践,详细总结了深溪锰矿床地层、构造、矿石等特征,并对锰矿的矿床成因进行了探讨。研究表明,深溪锰矿严格受地层层位控制,呈层状、似层状产于二叠纪茅口组第三段浅灰至灰黑色含锰岩系中,矿石矿物主要为菱锰矿,含少量黄铜矿、重晶石、毒砂等矿物,矿石为块状、斑杂状、角砾状构造,自然类型为碳酸锰矿石,工业类型为贫锰矿、富锰矿。分析认为深溪锰矿为深部的气液成矿物质喷溢至地堑盆地中沉积成矿,为"内生外成"的"古天然气渗漏沉积型锰矿床"。