模糊灰色聚类和组合赋权法在铁路信号系统可靠性评估中的应用

针对模糊综合评判法在进行列车运行控制系统可靠性评估时的不足,提出基于模糊灰色聚类和组合赋权法的可靠性评估方法,以更客观地评估铁路信号系统的可靠性,降低评估结果的不准确性和不可靠性。首先,利用组合赋权法分别计算CTCS-3级列车运行控制系统各子系统基本单元的权重。然后,采用灰色聚类法评估列车运行控制系统各子系统的可靠性。最后,在对列车运行控制系统子系统可靠性评估结果的基础上,结合各子系统权重值,利用模糊综合评判方法,评估整个列车运行控制系统的可靠性。结果表明,基于模糊灰色聚类和组合赋权法的可靠性评估方法能够实现CTCS-3级列车运行控制系统可靠性评估,评估结果符合实际情况。     

青藏高原农牧结合的功能、模式与对策

青藏高原民族众多 ,民族生存方式及资源利用形式的牧业化 ,构成了高原农业发展的一大特色。通过剖析透视高原农牧结合的功能特征 ,认为高原已形成核心农区、农区边缘地带、核心牧区、牧区边缘地带等4种可供选择的农牧结合生产模式 ,只有采取有效措施促进高原农牧业的有机结合 ,才有可能切实加快推进高原农业可持续发展的现代化进程 ,从而确保高原各民族人民的食物安全。     

Performance of pond–wetland complexes as a preliminary processor of drinking water sources

Shijiuyang Constructed Wetland(110 hm~2) is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water in the Xincheng River every day and supplies raw water for Shijiuyang Drinking Water Plant. Daily data for 28 months indicated that the major water quality indexes of source water had been improved by one grade. The percentage increase for dissolved oxygen and the removal rates of ammonia nitrogen, iron and manganese were 73.63%, 38.86%, 35.64%, and 22.14% respectively. The treatment performance weight of ponds and plant-bed/ditch systems was roughly equal but they treated different pollutants preferentially. Most water quality indexes had better treatment efficacy with increasing temperature and inlet concentrations. These results revealed that the pond–wetland complexes exhibited strong buffering capacity for source water quality improvement. The treatment cost of Shijiuyang Drinking Water Plant was reduced by about 30.3%. Regional rainfall significantly determined the external river water levels and adversely deteriorated the inlet water quality, thus suggesting that the "hidden" diffuse pollution in the multitudinous stream branches as well as their catchments should be the controlling emphases for river source water protection in the future. The combination of pond and plant-bed/ditch systems provides a successful paradigm for drinking water source pretreatment. Three other drinking water source treatment wetlands with ponds and plant-bed/ditch systems are in operation or construction in the stream networks of the Yangtze River Delta and more people will be benefited.     

串接组合式迷宫螺旋泵的气液两相流数值模拟及试验研究

为研究串接组合式迷宫螺旋泵在实际污水处理过程中的曝气增氧效果和内部的流动情况,应用计算流体力学FLUENT软件,基于混合物多相流模型,对串接组合式迷宫螺旋泵内部三维多相流场进行了数值模拟,分析了不同含气率条件下流场的压力、速度、气相分布情况,分析得出:泵的压力梯度在不同含气率下有所不同,但压力分布都是沿着轴向方向增加,增压效果明显;转子流域的速度明显高于定子流域,且随着含气率的增大,转子流域速度越来越小,定子流域速度越来越大;泵整体含气率比较均匀,随着含气率的增大,出口流域含气率明显高于进口流域和螺旋环流域,有大量气体聚集的现象。试验结果表明:泵的扬程模拟曲线和试验曲线基本吻合,扬程误差值在7%左右,说明数值模拟结果较为准确,串接组合式迷宫螺旋泵在进行气液混输时出口气泡均匀,水中含氧量多,具有良好的曝气增氧效果。     

生化和膜组合工艺在升级改造垃圾渗滤液处理工程中的应用

鞍山市垃圾填埋场渗滤液处理站,设计规模为300 m~3/d,经过升级改造后,采用A/O+外置MBR+NF+RO组合工艺。升级后其COD和色度去除率分别达到95%和99.6%,出水ρ(COD)<100 mg/L,出水无色透明,SS完全被去除,最终COD、NH_3-N、SS、TN、色度均达到GB 16889—2008《生活垃圾填埋场污染物排放标准》的要求。改造后夏、春、秋3季渗滤液处理费用约为25.77元/t,冬季的费用约为34.57元/t。     

改进彩管行业含铬废水处理工艺

针对彩管行业含铬废水处理工艺存在的不足,分别从还原剂和混凝剂两方面进行改进。通过比较和分析,最终提出了采用FeSO4作为还原剂处理含铬废水,氧化还原反应pH调节范围扩大,运行安全系数提高;利用新型高效混凝剂配合泥回流工艺,化学药品用量大幅下降,出水COD和SS含量显著减少。     

一种新型除尘器在梅山铁矿选厂的应用

介绍了喷雾双向旋流除尘器的原理及在矿山选厂除尘中的应用。     

Blends of karanja and jatropha biodiesels for diesel engine applications

Over a number of years, the work of exploring different biodiesels as an alternative to diesel fuel has been carried out worldwide. Not much focus on the use of combination of different biodiesels and their behaviour in diesel engines has been reported. This work is an attempt in this direction, which reports on the use of combination of biodiesels derived from jatropha and karanja oils. Jatropha oil methyl ester (JOME) and honge oil methyl ester (HOME) represent the respective biodiesels derived from these non-edible oils. Experiments were conducted on a four-stroke, single-cylinder diesel engine using these biodiesel combinations in order to check their feasibility as alternative fuels to diesel. Initially, experiments were conducted on each biodiesel and their blends with diesel and engine parameters were optimised in terms of injection pressure and injection timing. Advancing the injection timing improved the overall performance of the engine fuelled with JOME while retarding the injection timing favoured the HOME. Both biodiesels performed better with an injector opening pressure of 230 bar. Finally, experiments were conducted with the combination of both biodiesels with different blend ratios. It was observed that increasing the JOME content in the biodiesels blend improved the performance with reduced emissions of smoke, hydrocarbons and carbon monoxide emissions. However NO _x emission increased.     

石油降解菌的分离筛选及混合菌群的构建与优化

以河南濮阳油田超重质原油为研究对象,从污染井场土壤中分离并筛选出几株高效降解细菌、酵母菌和霉菌。由于不同类型微生物对碳源的利用目标和方式有所不同,而将3类不同类型菌种进行排列组合进行降解实验,最终优选出一组石油降解优势菌群。该文还利用正交优化法对降解菌的最佳添加量进行计算,结果显示,最佳接种量为X25：1．5％,Z3：1％,X18：1％,Z28：2％。利用该优化结果进行降解实验,石油的降解率在一定程度上提高了。在对濮阳、南阳和延长油田不同原油进行为期8d的降解实验中,显示了较高的降解效率,降解率分别为56．93％、65．66％、82．69％。实验证明,该降解菌群能不仅能有效够降解超重油,而且对重质原油和轻质原油表现出更好的降解能力。因此,该研究为石油污染物的降解提供了有效的菌种资源。     

陕西省能源消费的组合预测

组合预测理论及建模技术对于信息不完备的复杂经济系统具有一定的实用性。鉴于能源消费系统的复杂性及非线性的特征,文章首先利用陕西能源消费量的历史数据,分别采用指数回归模型、能源需求弹性回归模型及灰色模型建立了陕西省能源消费系统的单项预测模型。其次,采用标准差法进行非负权重分配,建立了陕西省能源消费量的组合预测模型。结果表明,加入时间虚拟变量和分段建模的预测精度明显提高,且组合预测模型的精度高于单项预测模型。最后,应用该模型对陕西未来10年的能源消费量进行了预测。