宁芜向山-皇姑山地区构造及黄铁矿找矿研究   总被引：5，自引：1，他引：4  

熊先孝  姚超美 《化工矿产地质》1999,21(1):15-23

宁芜向山－皇姑山地区,黄铁矿床赋存于基底火山喷发带、火山穹窿和NNE与NW向基底断裂交汇部位。通过多种手段综合研究,证实该区NNE向基底断裂为导矿构造,NE、NNE、NW向断裂构造为容矿构造。该区中生代二期构造应力场中NWW—SEE向主压应力场之共轭角高值区为黄铁矿富集地带。矿床受火山构造和地质构造双重控制,在皇姑山、莺子山、濮塘地区,云台山NE、SW方向,可能找到隐伏的黄铁矿矿床。  相似文献   

船闸浮式系船柱井的内支撑法施工     

王志勇  李传奇 《海岸工程》1999,18(3):33-38

浮式系船柱以其方便性而适用于水位变动大的船闸工程,本文系统介绍了内支法进行浮式系船柱井的施工,可供同类工程参考。  相似文献   

海洋生物技术育种的安全性控制与海洋农牧化     

杨俊杰  杨鸣 《海洋湖沼通报》1999,(4):77-82

海洋基因工程技术产业化前景广阔,市场潜力巨大,是当前世界海洋农牧化技术发展的主流。然而,从环境、生态、生物多样性、人体遗传与健康角度考虑,基因工程技术的发展过程中必须加强安全性控制。从国际经验来看,基因、转基因产品的产业化有较大的推广阻力。离不开市场化运营、政策引导和国家投资。与传统产品相比,在发展基因工程技术的同时,制定与国际接轨的基因技术产品发展政策、生产与控制规程以及相关标准势在必趋。  相似文献   

西南某巨型水电站地下厂房顶拱安全埋高解析解初步研究   总被引：2，自引：0，他引：2  

刘军  柴贺军  张倬元 《地质灾害与环境保护》2000,11(4):337-340

安全埋高是在研究该水电站地下厂房围岩稳定性时所提出的一个重大的工程地质问题,该问题的解决对综合理地设计地下厂房顶拱围岩支护结构具有重要的意义。目前该问题研究较少,本文探索了用结构力学的基本原理来解决安全理高的问题。研究结果表明该方法能够较好地解决该问题。并为进一步用数值模拟分析提供了依据。  相似文献   

The ALFA Laser and Analysis Tools     

S. Rabien  T. Ott  W. Hackenberg  A. Eckart  R. Davies  M. Kasper  A. Quirrenbach 《Experimental Astronomy》2000,10(1):75-88

The optimal performance of adaptive optics systems can only be maintainedif the wavefront reference is bright and compact.Experience has shown that both of these important criteria are remarkablydifficult to achieve with laser guide stars. This contribution gives an account of the methods by which ALFAattempts to reach them.First, the production of a high quality, high power laser beam isdescribed.However, this quality is unavoidably compromised along the path to thelaunch telescope.In order to rectify this, a new set of diagnostic tools which monitorthe quality of the out-going beam has been installed, and these arealso described.Lastly, we outline a number of possible modifications on which we areworking.If successful, these may allow a substantial improvement in the beamquality.  相似文献   

A neural network approach for the real-time detection of faults   总被引：2，自引：2，他引：0  

Yahya Chetouani 《Stochastic Environmental Research and Risk Assessment (SERRA)》2008,22(3):339-349

Fault detection is an essential part of the operation of any chemical plant. Early detection of faults is important in chemical industry since a lot of damage and loss can result before a fault present in the system is detected. Even though fault detection algorithms are designed and implemented for quickly detecting incidents, most these algorithms do not have an optimal property in terms of detection delay with respect to false alarm rate. Based on the optimization property of cumulative sum (CUSUM), a real-time system for detecting changes in dynamic systems is designed in this paper. This work is motivated by combining two fault detection (FD) strategies; a simplified procedure of the incident detection problem is formulated by using both the artificial neural networks (ANN) and the CUSUM statistical test (Page–Hinkley test). The design of a model-based residual generator is intended to reveal any drift from the normal behavior of the process. In order to obtain a reliable model for the normal process dynamics, the neural black-box modeling by means of a nonlinear auto-regressive with eXogenous input (NARX) model has been chosen in this study. This paper also shows the choice and the performance of the neural network in the training and test phases. After describing the system architecture and the proposed methodology of the fault detection, we present a realistic application in order to show the technique’s potential. The purpose is to develop and test the fault detection method on a real incident data, to detect the change presence, and pinpoint the moment it occurred. The experimental results demonstrate the robustness of the FD method.  相似文献   

Analysis on the Seismic Response of Soil Slopes Based on the Multi-point Input Method   总被引：1，自引：1，他引：0  

Li Li  Jing Pengxu  Xu Qin 《中国地震研究》2017,31(4):574-588

In general, the seismic response analysis in earthquake engineering assumes that the vibration parameters of the target and the contact surface of the external media are identical, i. e., single point input. However, earthquake energy has an attenuation phenomenon in wave propagation, so a wide range of soil slopes and the external medium contact surface of different input points on motion are not identical. If we consider single point input only, it may not correspond with reality, so it is necessary to carry out research on multi-point input methods. Based on the 2-D slope model, single-point input and multi-point input are performed respectively to analyze and compare their similarities and differences in the perspectives of the characteristics of seismic response of soil layer and plastic zone distribution to provide a reference for the seismic design of slopes. The results show that in the perspective of soil seismic response analysis, the peak acceleration output and peak velocity output under multi-point input are greater than the peak values under single point input at the same monitoring point, the peak appearing time is also earlier than that of the single point input; in terms of the plastic zone distribution, the multi-point effect is manifested as the presence of more obvious tensile shear failures; in the perspective of safety coefficient, the safety coefficient under each multi-point input is smaller than that of single point input, a difference of about 7% or so. In summary, multi-point input is more reasonable and practical than single point input, so multi-point input should be considered in seismic design.  相似文献   

A novel framework for regional collision risk identification based on AIS data     

《Applied Ocean Research》2019

Identification of regional collision risk in water area is of significance for the safety of navigation. However, traditional risk identification models are subject to the limitations in accuracy, short-term identification and traffic characteristics. Herein, a framework was put forward to identify regional collision risk instantaneously based on AIS data. The vessels were clustered by using the spatial clustering method. Afterwards, the framework was divided into two steps. Firstly, collision risk of each cluster was obtained by collision risk and contribution of the vessels within the cluster. An analytical method was adopted to identify collision risk of each vessel from the perspective of vessel pairs. Contribution of each vessel was determined by using improved Shapley value method in game theory. Secondly, regional collision risk was obtained by collision risk and contribution of each cluster. Case studies were carried out based on the AIS data of Northern Yellow Sea in China to validate the validity of the proposed framework. The results show that the proposed framework can effectively identify collision risk in water area, presenting the potential for collision risk monitoring and collision risk analysis of water area.  相似文献   

Safety evaluation of breakwaters based on physical and numerical modelling     

J.-M. Zhang  G. Wang  Y. Chen 《Ocean Engineering》2009,36(11):852-862

This paper highlights an integration of physical and numerical methods in evaluating a soil-breakwater system in coastal engineering. Centrifuge modelling is used to reproduce field phenomena and confirm the effectiveness of numerical methods. Numerical simulation incorporating finite element and limit equilibrium analysis is employed to explain the test results quantitatively and evaluate the deformation and stability of the complex soil-structure system. The results of physical and numerical simulation show that the proposed approaches work well and provide useful basis for potential applications to other coastal structures.  相似文献   

Artisanal fishing in Andalusia (and III): “The Day After…”     

Francisco Piniella  Milagrosa Casimiro Soriguer  Francisco Pastoriza 《Marine Policy》2010

During the past 5 years researchers from the University of Cádiz have carried out several studies on artisanal fishing in Andalusia, with the object of determining the state of the fleet and safety on board vessels. These studies have been financed largely with help from the European Union. In this third approach to the topic, the census of the fleet is updated and the changes that have taken place are considered from two perspectives: the influence of the policies implemented by the various governmental authorities, and the dynamic of the new commercial scenarios. For this study special emphasis is given to those communities in the SW of the province of Cádiz where the policies associated with the Treaties with the Kingdom of Morocco have had a decisive impact.  相似文献