Seasonal Water Level Manipulation for Flood Risk Management Influences Home‐Range Size of Common Bream Abramis brama L. in a Lowland River

The increased threat of flooding from climate change requires ever greater management of rivers to alleviate flood risk. Although the impacts of river modification on fish communities are well documented, the effects of river management practices on fish behaviour have received relatively little attention. Here, a long‐term (4 years) acoustic telemetry study was used to analyse the spatial–temporal behaviour of common bream in a lowland river system (River Witham, Lincolnshire, UK) in which water levels are artificially manipulated biannually as part of a flood storage strategy. Levels are lowered in the autumn and increased again in the spring, to increase in‐river winter flood storage capacity. Home‐range size varied according to season, with home ranges being larger in the spring and summer months in comparison with those recorded during the autumn and winter months. When water levels within the river system were artificially manipulated, the bream responded by altering their home‐range size, increasing it after the levels had been raised and reducing it following the lowering of the river levels. This is in contrast to the cumulative overall distances bream were recorded to travel, which were unaffected by water level manipulation, suggesting water level manipulation did not affect activity levels. Although such changes in behaviour do not necessarily equate to a negative impact on fitness, reduced home‐range size brought about by water level manipulation does have implications for habitat availability and the number of competitive, predatory and parasitic interactions encountered. Copyright © 2013 John Wiley & Sons, Ltd.     

电动搬运车辆斩波器的应用分析

介绍以蓄电池和串励直流电动机为动力的电动搬动车辆用斩波器的种类，型号，参数，电路原理和应用情况。     

面向电子商务的现代物流管理信息系统的开发

结合现代物流技术发展趋势，分析探讨了面向电子商务的现代物流管理信息系统的开发技术路线，关键技术内容，功能体系结构设计及分层逻辑模型设计。     

智能化立体车库优化车辆存取策略研究

通过对智能化立体车库的研究，提出了三种可提高车库效率的优化车辆存取策略，即分区存取、交叉存取和自调整策略。     

浅谈成都北部新都物流仓库问题及解决措施

仓储是现代物流的不可缺少的重要环节,是保证社会再生产过程顺利进行的必要条件,是加快商品流通,节约流通费用的重要手段。文中通过对成都北部新都区物流仓库的系统研究,根据自身观察到仓库作业中遇到的实际问题,并把理论知识和实践工作经验相结合,得出最佳的应急解决措施。以实现最大化降低仓库仓储成本和生产成本,提高仓储效率,实现高效仓储。     

华东电网抽水蓄能电站电能计划安排方式优化算法

针对华东电网调度管辖抽水蓄能电站容量不断增加的现状,综合考虑预计用电负荷、联络线送受电计划、电站出力特性等多种因素,为了最大限度地节能降耗、提高火电机组发电负荷率,以考虑抽水蓄能电站电能计划后的发电负荷率最大为优化目标,在实际工作中研究提出了华东电网抽水蓄能电站电能计划安排方式优化算法。实践应用中,华东电网已根据此优化算法开发了计算程序,用以为电能计划编制人员提供决策依据。经实践检验,该计算程序明显提高了华东电网抽水蓄能电站电能计划的编制质量和工作效率。     

基于液压传动的海流能蓄能稳压发电系统仿真

在海洋能发电装置中采用基于液压传动的蓄能稳压方式可以较好地实现能量的最大捕获和输出功率稳定。实现这一功能的系统主要由能量输入系统、液压系统、发电系统和自动控制系统等组成。文中首先对系统进行数学建模及计算机仿真,然后在半物理仿真试验台基础上,对各种工况进行了仿真研究。计算机和半物理仿真试验台的仿真结果表明,该系统可以实现海流能发电装置的变速恒频控制,从而实现能量的最大捕获和输出功率稳定。     

蓄滞洪区洪水调度优化研究

针对洪水调度中影响因素众多且有不确定性因素的特点 , 引入多目标模糊优选理论和方法 , 建立了蓄滞洪区洪水调度方案模糊优选模型。并将此模型应用于实际洪水调度中,有效地解决了受确定性因素和不确定性因素影响的蓄滞洪区洪水调度方案的多目标优化决策问题。     

原木随机存贮策略的最优化问题

介绍在周期内原木变价销售情况下的最佳期初贮存量的决策方法 ,在建立期望机会成本的数学模型基础上 ,探讨原木随机存贮策略的最优化问题。     

中国抽水蓄能电站运营现状分析

实地调查了中国 5省 (市 ) 8座抽水蓄能电站 ,并对它们的实际运行资料进行分析计算 ,论述了中国抽水蓄能电站的建设运营现状、存在的问题及其原因 ,指出了湖北电网兴建抽水蓄能电站应注意的有关问题。