中部引嫩引水口枯水临界期来水量及引渠现状过流能力分析

随着嫩江干流尼尔基水库的建成,嫩江枯水临界期中引引水口来水量发生变化,通过分析确定可能发生的来水量,并结合引渠现状,提出可引水量处理办法.     

火电厂贮灰场排洪坝进水口模型试验研究

对火电厂贮灰场排洪系统进水口进行了水工模型试验,在多工况下进行过流能力研究,观测了流态,并对流量系数进行了探讨,给出了排洪卧管进口段安全泄洪的工程措施.试验成果对类似工程有借鉴作用.     

进口空气相对湿度对直接蒸发冷却式空调机性能的影响

本文就进口空气的相对湿度对直接蒸发冷却式空调机性能的影响进行了分析,得出了在保证一定冷却效果的条件下冷却效率、填料厚度和出口空气相对湿度与进口空气相对湿度的关系曲线.     

河流结冰对电厂取水的影响

西北地区取用地表水作为电厂供水水源,都存在有三防(防冰、防沙、防水草)问题。本文根据多年来部分工程的调查及实地观测资料,对河流结冰过程、冰情演变和冰流量、冰厚的估算方法,以及目前电厂所采取的防治措施作了分析研究,提出了解决取水口结冰问题的途径。     

龙滩水电站左岸进水口边坡锚固预应力的实测研究

介绍了龙滩左岸进水口边坡预应力锚索监测成果，重点分析了锚固力损失和异常的原因。锚固力损失偏大的主要原因是:钻孔的精度和锚索的安装质量等引起锚索在张拉过程中的偏心，造成锁定损失偏大，部分钢绞线随着荷载的增大，松弛损失量也迅速加大;另外，受开挖等外界因素影响使锚索的受荷状态发生变化，锚固介质受到冲击或锚固结构的荷载发生变化等，均导致锚索预应力的损失（降低）。边坡下切过程中，由于地质条件较差使岩体产生变形是预应力锚索在运行过程中出现锚固力超张拉值的主要原因。     

睢宁水厂取水设计方案比选

睢宁水厂取水工程设计规模10万m3/d,水源取自庆安水库,采用两种取水方案进行比较,方案一为框架式取水头部、架空虹吸钢管引水;方案二为箱式取水头部、钢管埋地敷设,通过两种方案比较,得出了方案二具有投资低,施工方便及安全性高的优点,并针对该方案施工中的要点提出相应的技术措施,为取水工程的设计提供参考。     

Quantitative risk assessment on the dietary exposure of Finnish children and adults to nitrite

Nitrite intake from the consumption of cured meat and tap water was estimated for Finnish children of 1, 3 and 6 years as well as Finnish adults of 25–74 years. Nitrite content in the foods was measured by capillary electrophoresis, and was then used together with individual food consumption data from the FINDIET 2007 and DIPP studies in a stochastic exposure assessment by a Monte Carlo Risk Assessment (MCRA) program. Nitrite intake from additive sources and tap water was assessed, and more than every 10th child between the ages 3 and 6 years was estimated to have a nitrite intake exceeding the acceptable daily intake (ADI) of nitrite. The high exposure levels were caused by frequent consumption of large portions of sausages, up to 350 g day^–1 or 750 g in 3 days, among the children. Median nitrite intake from cured meat was 0.016, 0.040, 0.033 and 0.005 mg kg^–1 body weight day^–1 for children of 1, 3 and 6 years and adults, respectively. Bayesian estimation was employed to determine safe consumption levels of sausages and cold cuts for children, and these results gave rise to new national food consumption advice.     

Non-dioxin-like PCBs: a survey on fishery and aquaculture from the Mediterranean area

A sampling campaign from 21 sites in Italy was conducted: 15 species from fishery and three species from aquaculture, for a total of 40 determinations, were considered. A careful sample preparation preceded the instrumental analysis that was carried out by means of GC–ECD and GC–MS. Good laboratory practice was achieved by the participation in proficiency tests, by the use of certified reference materials and by applying other directives recommended by international organisations. Concentrations measured in this work were compared with a TDI proposed by some international bodies: for a person weighing 70 kg one-third of the samples from fishery, when consumed, lead to exceed this TDI if the average fish daily consumption per capita is considered. Based on the data obtained here some hypotheses on environmental spreading and influence of PCBs on human health are made. Some suggestions about the preparation of fish for consumption are also given.     

山溪坝后式取水及明渠弯道除沙方式研究

随着我国水利水电工程建设的发展,水电站分布越来越集中于偏远山区,供水系统往往需自行建设。为了解决工程建设施工及生活用水问题,通常是将工程附近水源水质较好的山溪作为取水点,并经简单沉沙处理后投入使用。传统的坝前式山溪取水及大型沉沙池除沙普遍面临着汛期取水头部易被泥石流淤积、山溪内施工部位狭窄等问题,根据弯道环流原理,结合杨房沟水电站供水系统取水头部设计及运行使用经验,研究验证了坝后式取水代替传统的坝前式取水,以及明渠除沙代替大型沉沙池除沙方式的实际效果。实践表明,新的取水方式可以满足抗淤能力强、施工占地少,同时除沙能力理想的要求,可为今后类似情况下山溪取水及除沙方式的选择提供参考。