云南绿春杨家寨金多金属矿矿床特征及成矿规律

杨家寨金多金属矿位于西藏—三江造山系,兰坪—普洱双向弧后陆内盆地与绿春陆缘弧带结合部,矿体近矿围岩主要为下二叠统高井朝组安山质凝灰岩及安山岩,少部分为石英斑岩,矿体就位于与莫马洛断层（F4）成锐角度相交的次级构造、层间破碎带及层间剥离—滑脱构造带.成矿作用共分三个阶段：早二叠世晚期——矿源岩（层）形成阶段,燕山早期——矿床形成阶段;燕山晚期——矿床定位阶段.矿床类型为浅成低温热液构造—蚀变岩型多金属矿床.     

A six-step practical approach to semivariogram modeling

Geostatistical prediction and simulation are being increasingly used in the earth sciences and engineering to address the imperfect knowledge of attributes that fluctuate over large areas or volumes—pollutant concentration, electromagnetic fields, porosity, thickness of a geological formation. Central to the application of such techniques is the need to know the spatial continuity, knowledge that is commonly condensed in the form of covariance or semivariogram models. Their preparation is subdivided here into the following steps: (1) Data editing, (2) Exploratory data analysis, (3) Semivariogram estimation, (4) Directional investigation, (5) Simple modeling, (6) Nested modeling. I illustrate these stages practically with a real data set from a geophysical survey from Elk County, Kansas, USA. The applicability of the approach is not limited by the physical nature of the attribute of interest.     

露天煤矿开挖工程承压含水层井点降水数值分析

在掌握某露天煤矿水文地质条件和抽水试验成果的基础上,通过利用Modflow建立了较合理的渗流数值模型,分析了井点降水中承压含水层水位随时间的下降过程,并进行了实际分析,结果与实际观测结果吻合良好。在此基础上,开展预测研究,为进一步露天煤矿开挖降水设计提供理论依据。     

Data assimilation for a coastal area morphodynamic model: Morecambe Bay

This paper investigates the use of data assimilation in coastal area morphodynamic modelling using Morecambe Bay as a study site. A simple model of the bay has been enhanced with a data assimilation scheme to better predict large-scale changes in bathymetry observed in the bay over a 3-year period. The 2DH decoupled morphodynamic model developed for the work is described, as is the optimal interpolation scheme used to assimilate waterline observations into the model run. Each waterline was acquired from a SAR satellite image and is essentially a contour of the bathymetry at some level within the inter-tidal zone of the bay. For model parameters calibrated against validation observations, model performance is good, even without data assimilation. However the use of data assimilation successfully compensates for a particular failing of the model, and helps to keep the model bathymetry on track. It also improves the ability of the model to predict future bathymetry. Although the benefits of data assimilation are demonstrated using waterline observations, any observations of morphology could potentially be used. These results suggest that data assimilation should be considered for use in future coastal area morphodynamic models.     

基于“灰箱”模型的海洋公共治理责任结构论证分析

海洋公共治理是我国政府治理现代化体系建设的重要组成内容。作为适应新时期"海洋强国"战略实施的海洋公共治理被认作一种异于传统陆地政府治理的新型地公共治理活动,存在着自身一定的责任结构体系。收集了2012-2016年的六大类海洋责任案例(主要是海洋执法案例),以时间(t)、案例数量(q)、制度(I)、人(H)来构建"灰箱"模型,通过考察问责复发率(P)分析海洋公共责任(R)的问题及原因。研究结果表明:(1)我国海洋公共治理过程中应亟须重视"海洋政府"理念,问责事件也从样本数量上得到了体现;(2)海洋公共治理的目标应是防范于未然,确保责任事件的可预期化,推进政府治理能力现代化,应当基于法治的导向来重新塑造海洋政府的责任体系;(3)我国未来海洋公共治理的责任体系建构应通过立法的方式实现责任人和责任形式的可预期化,最终实现对海洋公共治理责任法治监督的应有之义。     

Axial friction response of full-scale pipes in soft clays

The axial friction response of subsea pipelines in soft clays is a very important aspect for designers of subsea pipelines but the response is not well understood so far. There is a pressing need for the comprehension of the response. In this paper, model tests are performed using full-scale pipes coated with polyethylene (PE) to study the effects of the set-up period, the pipe diameter, the buried depth of the pipe, the shear strength of soft clays and the loading rate on the axial friction response of pipelines in soft clays. The variations of the axial friction coefficient are analyzed using the effective stress method based on model test results. The results show that the axial friction resistance increases with the increasing pipe diameter but the effect of the pipe diameter on the axial friction coefficient can be neglected. The ultimate axial resistance also increases with the increase of the buried depth of pipelines, the undrained shear strength of soft clays and the loading rate. The axial friction coefficient increases with the increasing loading rate. However, the axial friction coefficient decreases with the increasing buried depth. The method to determine the axial friction coefficient is developed by analyzing model test results, which considers the effects of the diameter, the buried depth, the undrained shear strength of soft clays and the loading rate. The study results not only extend the industry data base but also supply a basis to determine the axial friction coefficient of PE-coated pipes in soft clays for ocean engineering geological investigations.     

On the fairing of resistance test data: A software-based approach

A fairing method is presented for giving a good representation of ship model resistance test data, which in general tend to exhibit a scattered trend and need to be smoothed appropriately. One component of the test data originates from the frictional resistance and can be formulated smoothly. The second component is the wave resistance which exhibits a specific harmonic character with peaks and troughs. In this method, this component is modelled using suitable harmonic cosine terms for obtaining the best representation of the corresponding resistance data. The performance of the method is then tested on two example cases, using the characteristic parameters of the sample data as input during the smoothing process.     

Experimental analysis on the risk of vortex ventilation and the free surface ventilation of marine propellers

The paper presents a discussion of the ventilation inception and air drawing prediction of ships propellers, aiming to predict under what conditions ventilation will happen, and the actual physical mechanism of the ventilation.Three different types of ventilation inception mechanisms are included in our discussion: free surface vortex ventilation, ventilation by sucking down the free surface without forming a vortex as well as ventilation by propeller coming out of the water. Ventilation prediction is based on a series of model tests, where the propeller is tested in different levels of intermittent ventilation. The use of underwater video gives a visual understanding of the ventilation phenomena.Ventilation by vortex formation has analogies with other phenomena, such as the inlet vortex in pump sumps, ground vortex at the inlet of the aircraft engines and the Propeller Hull Vortex Cavitation (PHVC). The paper includes comparison between Propeller Hull Vortex Cavitation (PHVC) and Propeller Free Surface Vortex Ventilation (PFSVV) as well as comparison between PFSVV and vortex formations of aero engines during high power operation near a solid surface.Experimental data based on several different model tests shows the boundary between the vortex forming, non-vortex forming and free surface ventilation flow regimes. For comparison the following parameters, which determined the intensity of the hydrodynamic interaction between the propeller and free surface have been used: propeller load coefficient c_T, tip clearance ratio c/D, propeller submergence ratio h/R, ambient velocity V_i and flow cavitation/ventilation number σ_cav/σ_vent.     

Sea Levels and Coastal Inundation Due to Tropical Cyclones in Indian Coastal Regions of Andhra and Orissa

Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding.