Future aspects in marine ecosystem modelling

Existing ecosystem models are briefly presented and summarised. The problem of coupling physical and biological models as well as aspects of prediction and predictability are discussed. The general perception that marine ecosystems are inherently unpredictable due to non-linearity becomes questionable if the response of climate variability in marine ecosystems is analysed. Many authors have shown correlations between climate variability and the variability of abundance or biomass of marine organisms such as phytoplankton, zooplankton, benthos or fish recruitment in different parts of the world ocean. In the northern hemisphere, certain species show a linear response to climate variability mainly during winter and spring. However, the underlying mechanisms are not well understood. Often, a phase lag can be observed between climate variability and the reaction of organisms. The identification of a plausible mediator between climate and biology is difficult, since all possible physicochemical mechanisms having a direct or indirect influence on the variability of abundance or biomass of marine organisms have to be considered as mediator.The understanding of the reason of the phase lag, which possibly implies a “biological memory”, and the identification of all possible mediators are necessary to predict the response of marine organisms to climate variability. The identification of mediators will result in an improvement of coupled models, a deeper understanding of physical–biological interaction and the improvement of predictive capability of marine ecosystem models.     

雷克萨斯ES300 ABS的结构原理及故障检修

主要进述丰田雷克萨斯(凌志)ES300车防抱死制动系统(ABS)的结构,主要零件的检修,以及ABS轿故障灯常亮的故障诊断与排除。     

TY180推土机工作装置液压系统常见故障及诊断

分析了TY180推土机工作装置液压系统的工作原理、组成结构及其典型故障,总结了常见故障的现象及其形成原因,提出了相应的排除措施;运用因果分析法、故障树分析法等故障诊断方法,绘制了推土铲刀不动或上升无力故障的鱼骨图和松土器油缸不动故障的故障树,明确了这2种故障的成因与相应结果之间的逻辑关系。实践证明:运用上述方法能够较快地诊断和排除推土机工作装置液压系统的故障,提高机械工作的可靠性,为工程机械液压传动系统故障检测与维修提供一定的理论依据。     

Prediction Approach to Life on Wing for Civil Aeroengine

To reduce engine maintenance cost and support safe operation, a prediction method of engine life on wing was proposed. This method is a kind of regression model which is a function of the condition monitoring and failure data. Key causes of engine removals were analyzed, and the life limit due to performance deterioration was predicted by proportional hazards model. Then the scheduled removal causes were considered as constraints of engine life to predicte the final life on wing. Application of the proposed prediction method to the case of CF6-80C2A5 engine fleet in an airline proved its effectiveness.     

磷酸铵镁技术中不同沉淀剂脱氮除磷效果比较

探讨了磷酸铵镁法中不同沉淀剂的脱氮除磷效果,比较了氨氮去除率、磷酸盐去除率、残氮量、残磷量,沉淀物质质量和组成,处理液的电导率。综合考虑了各方面因素得出处理高浓度氨氮废水的较佳的沉淀剂为Na3PO.412H2O+MgCl2.6H2O和Na3PO4.12H2O+MgSO4.7H2O,处理高浓度磷酸盐废水的较佳的沉淀剂为NH4Cl+MgCl2.6H2O和NH4Cl+MgSO.47H2O.并对磷酸铵镁沉淀进行了X-衍射光谱和扫描电镜表征。     

海事部门管理沉船打捞问题研究

文中结合沉船打捞海事管理工作实践与经验,系统分析了海事沉船管理存在的问题,并提出相应的对策和建议,以促进海事沉船科学监管。     

新场镇农村生活污水处理现状及问题探讨

该文综述了目前新场镇农村生活污水处理的现状,对采取的3种不同类型的污水处理设施进行了介绍,并根据监测数据,对不同设施的处理效果和达标排放进行分析,最后提出新场镇农村生活污水处理工程在推进过程中必须解决的问题。     

远洋船舶NOx排放量的测量

针对营运船舶上柴油机的实船NOx排放测量,给出了一种通过实际测量少数几个数据,便可推算出NOx排放值的方法.这样就可利用简单小型设备进行实船测试,从而使船舶柴油机的实船排放测量变得容易操作,根据其测量值判断是否符合的排放要求.     

杭州湾大桥现浇墩身施工监理实践

杭州湾大桥北航道桥及南航道桥高墩区高度大于15m的68个墩身采用现浇工艺,截面型式分为3类。墩身最大高度42．5m,施工有效天数少,施工精度高,安全风险大。监理工程师对现浇墩身测量放样、模板制作安装、钢筋制作安装、混凝土浇筑和养护、拆模和验收等进行全过程的质量监控,并按照承包人自检频率的25％进行抽检。     

非能动余热排出系统模化及验证分析

模化理论是核反应堆安全系统试验验证的基础。文中以国外某核电厂的非能动余热排出系统为对象,通过模化分析确定一回路失电事故工况下非能动余热排出系统的模化比例系统;采用RELAP5/MOD3.2软件对工程原型和模化系统进行了数值计算,数值结果验证了非能动余热排出系统模化分析的正确性。