Estimation of Land Subsidence Based on Groundwater Flow Model

This article presents an approach for estimating land subsidence due to withdrawal of groundwater. The proposed method calculates the groundwater seepage in 3-D-condition and calculates the land subsidence one-dimensionally. The governing equation on groundwater seepage is based on the three-dimensional mass conservation law and the principle of effective stress. The land subsidence calculation method is derived based on the following assumptions: (1) displacements occur only in the vertical direction, and (2) in vertical direction the total stresses do not change. The governing equation is solved by numerical method, i.e., finite element method (FEM) in spatial discretization and finite difference method (FDM) in time series discretization. In FEM Galerkin method is adopted and in FDM, lumped matrix method is employed. The proposed method is calibrated via analyzing 1-D consolidation problem and the results are compared with those from Terzaghi's one-dimensional consolidation theory and oedometer test. The proposed method is employed to analyze the consolidation of a soft layer due to withdrawal of groundwater from an aquifer under it. Moreover, this method is also applied to a field case of land subsidence due to groundwater pumping in a gas production field in Japan. The analytical results are compared with the field observed data. The results show that this approach simulates the field case well.     

A hierarchical real-time control architecture for a semi-autonomous underwater vehicle

This paper describes a real-time control architecture for Dual Use Semi-Autonomous Underwater Vehicle (DUSAUV), which has been developed at Korea Research Institute of Ships and Ocean Engineering (KRISO) for being a test-bed of development of underwater navigation and manipulator technologies. DUSAUV has three built-in computers, seven thrusters for six DOF motion control, one 4-function electric manipulator, one ballasting motor, built-in power source, and various sensors. A supervisor control system with GUI and a multi-purpose joystick is mounted on the surface vessel and communicates with vehicle through a fiber optic link. Furthermore, QNX, one of real-time operating system, is ported on the built-in control and navigation computers for real-time control purpose, while Microsoft OS product is ported in the supervisor computer for GUI programming convenience. A hierarchical control architecture, which consists of application layer, real-time layer and physical layer, has been developed for efficient control system of above complex underwater robotic system. The experimental results with implementation of the layered control architecture for various motion control of DUSAUV in an ocean engineering basin of KRISO is also presented.     

锯缘青蟹胚胎发育过程主要生化组成

锯缘青蟹胚胎３种主要生化组成以蛋白质含量为最高，脂类含量次之，碳水化合物含量最低。胚胎发育的结果导致三种主要生化组成含量降低，其中蛋白质减少了３９．０％，脂类、碳水化合物含量分别减少了１７．０％、７．７％，说明蛋白是青蟹胚胎发育的主要能源物质，这可能与动物适应热带、亚热带的水生环境有关。     

酸雨的研究进展及厦门酸雨研究的趋势

本文综述了国内外酸雨的研究现状；包括酸雨的来源、成因、模式、影响及防治对策；介绍了酸雨的研究趋势；并着重就厦门地区今后酸雨的研究方向提出也作者的看法。     

官井洋大黄鱼标志放流技术与放流标志鱼早期生态习性的初步研究

用人工培育的大黄鱼幼鱼，经丁香酚溶液浸浴麻醉，体背系挂塑料牌，经 网箱暂养后于１９８７年１月２０日在官井洋中放流６ １２６尾。２个月内回捕４８３尾。 通过对回捕鱼及其捕捞实况调查，并结合定置网渔获物中天然大黄鱼及海区温盐 断面调查，对放流标志鱼早期的生态习性进行了初步研究。     

山东沿海旅游业可持续发展对策研究

滨海旅游是旅游活动的重要组成部分 ,在我国具有广阔的发展潜力。在讨论了山东沿海旅游业发展中存在的问题的基础上 ,指出发展滨海旅游与滨海和海洋环境之间的相关关系 ,探讨了使山东沿海旅游业可持续发展的主要对策     

粘土矿物对海水中主要营养盐的吸附研究

对海水中磷盐和硝酸盐在粘土矿物上的吸附行为的研究发现，海水体系中高岭土对磷酸盐的吸附能力大于蒙脱土，其原因为，粘土颗粒的表层铝／硅结构比是控制磷酸盐吸附的主要因素，其中铝含量越高，肿附能力越大。考察ＰＨ、粘土酸改性处理等因素对吸附作用的影响，结果表明，ＰＨ＜８．５的磷酸盐吸附ＰＨ曲线呈峰形，其吸附作用以阴离子交换为主；ＰＨ＞８．５时磷酸盐的吸附作用以沉淀吸附为主。酸改性蒙脱土可提高吸附磷酸盐的能力     

上新世——早更新世青藏高原北缘隆升的磁性地层学证据

对新疆叶城剖面西域砾岩及下伏第三纪地层的磁性地层学研究表明 ,西域砾岩的沉积时代为晚上新世至早更新世 ,磁性地层年龄为 3.5至 <1.8Ma。阿图什组沉积于早上新世 ,古地磁年龄为 4 .6～ 3.5 Ma。阿图什组以砂岩和粉砂岩为主夹薄层砾岩 ,为河流相及冲积扇前缘相。西域砾岩以厚层砾岩为主夹风成粉砂岩 ,为典型洪积—冲积扇堆积。西域砾岩的沉积反映了青藏高原北缘晚上新世至早更新世强烈的隆起和剥蚀     

Steady Response of a Ventilated Thermocline to Enhanced Ekman Pumping

The steady response of the ventilated thermocline to an increase in Ekman pumping is investigated, focusing on the effect of the mixed layer depth distribution on the subsurface density anomaly. We consider only the subtropical gyre, and the mixed layer is assumed to be deep in the northwest and shallow elsewhere with a narrow transition zone separating the deep and shallow mixed layer regions. At the intersection of this narrow transition zone and the outcrop line, low potential vorticity fluid is subducted into and ventilates the thermocline. In such a situation, an enhancement of the Ekman pumping confined to the northern subtropical gyre leads to pronounced subsurface cold anomalies in the southern subtropics, which is free of anomalous forcing. These density anomalies are much greater than those that occur when either the mixed layer depth is zonally uniform or the Ekman pumping is enhanced in the whole subtropical gyre. They are caused by anomalous changes in the trajectory of the low potential vorticity fluid in response to anomalous Sverdrup flow. This revised version was published online in July 2006 with corrections to the Cover Date.     

The light curved in the CM field

In this paper we introduce the CM field in Sections 2 and 3 based on the paper by Wang and Peng (1985), and calculate the light curved in the CM field in Section 4. The result shows thatP makes _CM larger than _C at , and smaller at . Under a special circumstance which source, CM lens, and observer are in the same line, if we get | ₀₌₀ , and | _=/2 , we can determine theP(M) andQ(M) of the CM lens,M is the mass of the CM lens.