U.S. Fishery Management Councils as Ecosystem-Based Management Policy Takers and Policymakers

The United States has a new national ocean policy that adopts ecosystem-based management (EBM) as its first principle for managing U.S. ocean spaces and marine resources. However, U.S. laws that govern the uses of ocean spaces present a challenging tangle of authorities and mandates that do not easily facilitate ecosystem-based policies. For over 30 years, U.S. marine fisheries management has been guided by eight Regional Fishery Management Councils. Working under the many laws that guide setting stewardship priorities for ocean ecosystems, councils provide the Federal Government with advice on fisheries harvest levels, fish habitat protections, and fishing community needs. Implementing EBM for any ocean ecosystem requires a careful examination of the laws and policy processes that affect human interaction with that ecosystem. This article explores the U.S. perspective on federal ecosystem-based fisheries management, its part in U.S. national ocean policy, and how fishery management councils might position themselves as both EBM policymakers and policy takers for ocean resource management.     

基于B/S的船舶机务管理系统公共数据服务平台设计

为了改善传统船舶机务管理系统成本高、维护难、效率低的现状及适应当前计算机技术的迅速发展,采用云计算和Web技术,建立基于B/S架构的机务管理系统公共数据服务平台,采用模块化设计思想,在传统机务管理系统的基础上增加权限管理和能源管理模块,不仅提高了机务管理系统的可维护性、可扩展性、易开发性和安全性,也提高了船员的工作效率和船舶的适航能力.     

Mode jumping in the lateral buckling of subsea pipelines

Unburied subsea pipelines under high-temperature conditions tend to relieve their axial compressive stress by forming localised lateral buckles. This phenomenon is traditionally studied under the assumption of a specific lateral deflection profile (mode) consisting of a fixed number of lobes. We study lateral thermal buckling as a genuinely localised buckling phenomenon by applying homoclinic (‘flat’) boundary conditions. By not having to assume a particular buckling mode we are in a position to study transitions between these traditional modes in typical loading sequences. For the lateral resistance we take a realistic nonlinear pipe-soil interaction model for partially embedded pipelines. We find that for soils with appreciable breakout resistance, i.e., nonmonotonicity of the lateral resistance characteristic, sudden jumps between modes may occur. We consider both symmetric and antisymmetric solutions. The latter turn out to require much higher temperature differences between pipe and environment for the jumps to be induced. We carry out a parameter study on the effect of various pipe-soil interaction parameters on this mode jumping. Away from the jumps post-buckling solutions are reasonably well described by the traditional modes whose analytical expressions may be used during preliminary design.     

我国《海商法》下提单运输若干问题之完善

我国《海商法》提单运输部分吸收了三大国际公约成熟合理的内容,反映了现代海运规则,但是仍有许多不足之处。本文对《海商法》需要改进的问题,如电子提单问题、迟延交货责任问题等提出了一系列修改意见。     

基于自抗扰的反步非奇异终端滑模船舶航向控制器设计

针对船舶受到不确定干扰的情况下不能准确、快速地跟踪期望航向的问题,设计一种基于自抗扰技术的反步非奇异终端滑模航向控制器,该控制器通过跟踪微分器对期望航向及其微分进行精确提取,通过线性扩张状态观测器实时估计并补偿系统内部和外部的总扰动,引入一阶低通滤波器,有效避免传统反步法中出现的"微分膨胀"问题,利用反步非奇异终端滑模控制技术设计控制律,提高系统的响应速度、抗干扰性和控制精度,通过构造Lyapunov函数证明了系统的稳定性。Simulink仿真试验证明,控制器在不同外界条件下均可对期望航向进行准确、快速地跟踪,具有较强的鲁棒性。     

多相流试验台管道上弯管内流场分析

利用ANSYS软件中FLOTRAN CFD对多相流的弯管处流体流场进行建模、划分网格、加载,分析得出流体流经弯管处的压力分布图和速度矢量分布图。探寻流体在流经弯管时速度和压力的变化,找出造成压力损失的主要原因,并找到管道内易损坏的部位,为多相流系统的设计提供合理的依据。     

基于B/S的起重船舶实时监测系统的研究

分析基于B/S结构对船舶进行实时监测的应用技术,通过对C/S与B/S模式原理及优缺点的比较,提出了采用B/S结构,克服了传统C/S模式在实时监测系统中的不足,在具体运用工具方面,项目中选用了ASP ADO的技术,实现数据库的访问功能,并设计了公司端服务器软件的相应用户使用流程.     

铁路施工方案管理信息系统设计

介绍我国目前铁路线路施工方案编制和管理的现状,依据软件工程的理论,对铁路施工方案管理进行需求分析和数据流程分析,提出基于B/S模式的铁路施工方案管理信息系统架构模式.并对系统的设计目标、模块化结构、网络安全措施、数据库安全措施进行详细的分析与设计,最后简要阐述系统应用情况.     

轻型货车转向架试验简介

介绍了为美国315K货车开发的轻型转向架在FAST试验线的试验结果.     

基于B/S的车辆管理信息系统的设计与实现

在对某供电公司车辆的运行现状分析的基础上,提出利用现在大多数公司都已经建立起来的局域网建立基于B/S模式的车辆管理系统的方案,有效地解决人工管理或半自动化管理带来的效率低下和准确性不够等问题.