极端海况下深水单点系泊系统FPSO运动响应分析

针对500年一遇的极端海况条件,对15万吨深水单点系泊系统FPSO的运动响应和系泊线受力特性进行了研究,为FPSO后续的基本设计和详细设计提供技术分析依据.基于水动力计算软件AQWA和ORCAFLEX,分别研究了500年一遇海况波浪主控环境条件、风主控环境条件、流主控环境条件对15万吨深水单点系泊FPSO运动响应的影响.计算结果表明:压载状态下运动响应幅值普遍大于满载状态下的运动响应幅值,波浪主控环境条件对FPSO运动响应的影响要明显大于风流主控环境条件,且风浪流成夹角作用时FPSO运动响应更大.     

升船机适用条件的研究

探讨升船机适用条件,提出升船机在优化航道网、提高航道通航效率中的作用。升船机的省水特点决定了它在我国中西部地区航道开发建设中的地位。升船机也是解决高坝通航一种非常有效的手段。     

Estimation of wheel–rail contact conditions and adhesion using the multiple model approach

This paper presents the development of a multiple model estimation approach for the identification of the adhesion limit to overcome the problem of the wheel slip/slide at the rail wheel-rail contact. The contact characteristics at the rail wheel-rail interface are both highly nonlinear and subject to changes due to exposure to external contaminations. The detection of adhesion and its changes is therefore scientifically challenging, but would provide a critical information in the control of trains to avoid undesirable wear of the wheels/track but also the safety compromise of rail operations. This study exploits the variations in the dynamic behaviour of the railway wheelset caused by the contact condition changes and applies a bank of Kalman filters designed at selected operation points for the adhesion estimation. A fuzzy logic system is then developed to identify the contact conditions by examining the residuals from the Kalman filters.     

大连港大连湾通用杂货泊位工程护岸及防波堤结构比选

介绍大连港大连湾通用杂货泊位工程设计和施工条件,在此基础上介绍护岸和防波堤的设计方案优选及该工程的造价比较。     

SDGJ-B型受电弓试验台的研制

为解决目前受电弓试验台接线繁琐及消除电气干扰,应用现代蓝牙微网技术,设计制造了SDGJ-B型便携式受电弓试验台,达到了机车状态检修试验设备漫游上车的目的。现场使用表明其性能优良,测试数据准确可靠。     

固结拉索近似频率方程求解条件的对比研究

利用文献[1]得出的近似频率方程和求解条件,结合Rayleigh定理和经典弦的频率公式,推导拉索近似频率方程的求解条件及其参考值,扩大近似频率方程的使用范围。通过数值算例,将文献[1]和本文求解条件的合理性和可靠性进行对比研究,其结果可用于快速测试拉索索力。     

排水沟渠在道路排水系统中的计算分析与应用

排水沟渠的成功应用可使排水系统水流顺畅、工作有效。该文采用实地调查及理论分析的方法,分析了排水沟渠的分类,给出了三角形边沟、带低洼区三角形边沟、矩形及梯形边沟、半圆形边沟及皿型边沟等排水沟渠的流量计算公式,讨论了其在曲线段的流态,提出了不同形式排水沟渠的适用条件,可对排水沟渠的设计起到较好的指导作用。     

Climate–ocean variability and Pacific hake: A geostatistical modeling approach

Climate forcing of the California Current has been known to impact the distribution and abundance of a number of local fish populations, but the mechanisms involved remain poorly understood. Climate metrics such as the Pacific Decadal Oscillation (PDO) and the El Niño Southern Oscillation (ENSO) are usually used to represent climate processes and direct links are made between climate forcing and production variability. This involves aggregation of impacts across large spatial scales and range of species. However, fluctuations in productivity are often the result of changes in physical habitat. In order to fully understand the relationship between climate and productivity, habitat changes should be addressed. In this study we use a geostatistical approach to quantify adult Pacific hake habitat during different climate regimes. Several authors have suggested that the distribution and intensity of the sub-surface poleward flow (the undercurrent) plays a key role in defining adult hake habitat along the west coast of North America. Here we build a model designed to predict hake habitat distribution in space based on sub-surface poleward flow distribution and bottom depth. Our results show that hake habitat expands in 1998 El Niño year compared to 1995. Given the important predatory role that hake plays in the CC, the amount and distribution of adult hake habitat has large implications for the Pacific Northwest food web and could thus serve as an ecosystem indicator representing important physical–biological interactions. Spatially based ecosystem indicators such as the one we develop here address two important yet neglected areas in the ‘Ecosystem Indicators debate’: the importance of developing metrics explicitly representing spatial and environmental processes shaping ecosystem structure. Without these, our power to fully describe ecosystems will be limited.     

不同地区花岗岩的工程地质条件、不良地质现象及治理对比

对发育于山东马站至莱芜高速公路和湖南临湘至长沙高速公路花岗岩发育区岩体的分布、组成、结构、成因、地质构造背景等工程地质条件、所存在的不良地质现象和特殊性岩土等分别进行了对比分析;同时针对两地花岗岩发育的不同地质、气候环境、不良地质差异,分别提出了相应的治理措施。     

市政道路下穿城市复杂区域隧道工程总体方案设计

通过对康王路下穿流花湖隧道工程复杂建设条件下控制因素分析,提出合理的总体设计方案,旨在探求在复杂建设条件下城市大型隧道工程科学合理的工程全局构思理念。城市道路隧道设计是一个综合性课题,与地形、地貌、工程地质、水文地质、社会人文和环境等多方面因素密切相关,它需要设计者在满足设计规范的前提下,对涉及方案的影响因素和控制条件进行逐步分析,理清主次,结合路网规划、隧道埋深、洞口位置及洞外接线、工期等综合考虑,进行多方案比较,从而合理得出最有利的道路方案和隧道方案。