川西坳陷蓬莱镇组构造—充填层序特征

川西坳陷上侏罗统蓬莱镇组为前陆盆地上红层碎屑岩建造。笔者应用成因地层学原理和层序地层学研究方法,对川西地区蓬莱镇组开展露头层序,测井层序及地震层序的综合研究,划分出区域上可供对比的５个构造－充填层序（Ｓ１－Ｓ５０,并对每个层序的层序界面,沉积体系和岩相古地理展布与演化特征进行了讨论,为查明蓬莱镇组沉积相的时空配置关系,正确建立区域地层格架,开展有利储集相带的预测奠定基础。     

北戴河西海滩人工岬湾养滩规划研究

在介绍静态平衡岬湾和人工养滩技术的基本原理以及设计方法的基础上,针对北戴河西海滩恢复治理工程进行了规划设计。应用静态平衡岬湾模式,规划设计了西海滩采用弧形突堤和离岸潜堤构成的人工岬头,形成三湾弧形稳定岸线形态,结合当地海况和补给泥沙来源,设计了人工养滩剖面和方法,为西海滩提供了多功能、高层次的开放游憩空间。 对于我国即将开展的人工养滩具有较大的示范意义。     

机车荷载作用下青藏铁路多年冻土区普通路基的蠕变分析

基于青藏铁路北麓河试验段的机车现场实时振动监测,在三轴流变试验的基础上,利用ABAQUS有限元软件中的时间硬化与Druker－Prager屈服破坏准则耦合的蠕变模型,对青藏铁路多年冻土区的普通素土路基在等效机车荷载作用下的蠕变效应进行分析。研究表明,ABAQUS软件中时间硬化与蠕变模型能较好地模拟路基运营过程中的时间效应,素土路基的竖向位移由路基顶部中心位置向路基内部和两侧逐渐减小,一年中的最大位移达14 mm,与该段的年沉降变形观测值一致。路基中心的蠕变应变值大于路基顶面和天然地表的应变值,路基中心受机车荷载的振动影响最大     

TOGA-COARE IOP期间的海气通量观测结果

在TOGA－COAREIOP期间用涡度相关法对海气热通量进行了船载直接观测．对垂直风速、温度和湿度湍流脉动观测数据的谱分析显示它们在高频区基本满足"－2／3次方律"．对船体简谐震荡影响的讨论从理论上证明该影响在热通量计算中可被忽略．根据以此方法得到的通量求出了中性层结条件下感热和潜热的整体输送系数分别为2．25×10^－3和1．26×10^－3．对海气边界层特性的分析表明该海域的近海层主要呈中性或弱不稳定层结．海气通量的变化与背景环流形势密切相关,潜热通量主要受海面风场强度的影响,而感热通量变化除了风场的影响外,层结变化也是一个重要因素．用整体输送法计算TOGA－COAREIOP期间以及TOGA期间8个航次的通量结果而得到的Bowen比约为0．1,显示潜热通量是暖池大气的主要热源．     

奉化亭下水库3维防洪调度仿真系统的研究与实现

阐述了采用3维虚拟仿真、地理信息和数据库等技术,开发奉化亭下水库3维防洪调度仿真系统,给出了系统的总体技术方案、总体框架及关键技术,实现了系统的具体功能.     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.     

Analytical and numerical study of the ground-track resonances of Dawn orbiting Vesta

The aim of Dawn mission is the acquisition of data from orbits around two bodies (4) Vesta and (1) Ceres, the two most massive asteroids.Due to the low thrust propulsion, Dawn will slowly cross and transit through ground-track resonances, where the perturbations on Dawn orbit may be significant. In this context, to safety go the Dawn mission from the approach orbit to the lowest science orbit, it is essential to know the properties of the crossed resonances.This paper analytically investigates the properties of the major ground-track resonances (1:1, 1:2, 2:3 and 3:2) appearing for Vesta orbiters: location of the equilibria, aperture of the resonances and period at the stable equilibria. We develop a general method using an averaged Hamiltonian formulation with a spherical harmonic approximation of the gravity field. If the values of the gravity field coefficient change, our method stays correct and applicable. We also discuss the effect of one uncertainty on the C₂₀ and C₂₂ coefficients on the properties of the 1:1 resonance. These results are checked by numerical tests. We determine that the increase of the eccentricity appearing in the 2:3 resonance is due to the C₂₂ and S₂₂ coefficients.Our method can be easily adapted to missions similar to Dawn because, contrarily to the numerical results, the analytical formalism stays the same and is valid for a wide range of physical parameters of the asteroid (namely the shape and the mass) as well as for different spacecraft orbits.Finally we numerically study the probability of the capture in resonance 1:1. Our paper reproduces, explains and supplements the results of Tricarico and Sykes (2010).     

基于排队论的销售模型分析

为降低企业销售时的综合成本,利用随机服务系统理论分析了顾客到达企业时的排队方式,得出单队多服务通道比多队多服务通道排队方式更优;分析了窗口之间相互帮助、同时为k个顾客服务、服务率可变、有多个顾客类以及是否需要雇佣帮手等多个服务模型,为企业选择适合自己的服务方式提供理论依据,并结合例题说明了选择恰当的服务方式能有效降低综合成本;还分析了库存容量对综合成本的影响,并得出最优库存容量.     

顾及轮廓信息和DRLSE模型的遥感影像瞬时水边线快速提取

针对利用传统瞬时水边线提取方法处理高分辨率遥感影像存在提取结果不连续、效率不高和无法同时提取多片水域等问题, 提出了一种顾及轮廓信息和距离正则化水平集演化(distance regularized level set evolution, DRLSE)模型的遥感影像瞬时水边线快速提取方法, 并将其应用于福建泉州附近海域瞬时水边线提取。首先,使用DRLSE模型提取地物轮廓信息, 以解决经典阈值方法水边线提取结果不连续问题; 其次, 利用DRLSE模型的初始矩形轮廓中心位置和周长信息, 对噪声点等轮廓进行自动剔除, 并提取多片水域, 以提高瞬时水边线提取后处理效率。研究结果表明:相较于泛洪算法、Canny算子和CV(Chan-Vese)模型, 应用本方法进行大陆海岸线瞬时水边线提取更高效, 且提取结果连续、精度更高。     

预加固高填方边坡滑动破坏的离心模型试验研究

2009年10月3日,攀枝花机场260×104 m3万方的高填方预加固边坡整体失稳,沿基覆界面下滑,并超覆于其下方的易家坪老滑坡之上,使易家坪老滑坡再次复活。这一填方边坡失稳事件最终导致机场停航两年。通过大型离心模型试验,再现了攀枝花机场预加固高填方边坡的滑动失稳过程,获得了边坡变形破裂的特征参量,阐明了边坡的滑动失稳机制。研究表明：天然工况下,边坡变形以坡顶沉降和沿基覆界面软弱层的蠕滑为主,坡体总体处于蠕滑变形状态;降雨和地下水工况下,坡体中后部拉张破裂和中前部挤压变形显著,具有塑性流动及推移式破坏特征,并最终产生溃滑失稳;预加固抗滑桩承受较大的边坡变形推力,且越靠近坡体后部的桩推力越大,最终从后向前逐排产生累进性剪断破坏,说明该填方边坡多排抗滑桩的平面布置和受力确定欠合理;降雨和地下水工况下,坡体的最大孔隙水压力是天然工况下的3.7倍,孔隙水压力对坡体失稳有重要作用;通过模型和原型的综合对比分析,该边坡的滑动失稳机制为推移式蠕滑-累进性折断-溃滑与超覆。