城市污水的层流换热特性理论

为有效利用城市污水热能,以污水源热泵系统中的流动工质——城市污水为研究对象,通过理论分析的方法,对其层流状态下的换热特性进行理论推导和实验验证.结果表明:污水作为热泵的冷热源,有良好的换热特性,推导得出的换热准则关联式h=4.53λ/D,为污水源热泵系统设计提供依据,同时为应用污水余热技术提供理论基础.     

Effective prediction of DEA model by neural network

In this paper,a fast neural network model for the forecasting of effective points by DEA model is proposed,which is based on the SPDS training algorithm.The SPDS training algorithm overcomes the drawbacks of slow convergent speed and partially minimum result for BP algorithm.Its training speed is much faster and its forecasting precision is much better than those of BP algorithm.By numeric examples,it is showed that adopting the neural network model in the forecasting of effective points by DEA model is valid.     

Relation between structural evolution of the Longmenshan orogenic zone and sedimentation of its foreland basin

In order to determine the area for oil and gas exploration in China's north Sichuan basin, we have divided the time during which the Longmenshan foreland basin was formed into five periods, based on the sedimentary response relationship of the fore-land basin to structural evolution: 1) a late Triassic Noric period; 2) an early-Middle Jurassic period; 3) a late Jurassic to early Cre-taceous period; 4) a late Cretaceous to Paleogene-Neogene period and 5) the Quaternary period. As well, we analyzed the sedimen-tary environment and lithologic features of every basin-forming period. The results show that there are several favorable source-reservoir-cap assemblages in our study area, making it a major region for future oil and gas exploration in China's northern Sichuan basin.     

pH值对城市生活污水短程硝化的影响

为实现废水处理过程中的短程硝化及反硝化脱氮中亚硝酸盐的积累以控制硝化反应的类型,以试验的方式,采用SBR工艺研究了pH值对不含海水的城市生活污水和含30%海水的城市生活污水短程硝化的影响.试验结果表明:对于不含海水的城市生活污水,单纯提高pH值来提高游离氨浓度并不一定能够实现短程硝化;对于含30%海水的城市生活污水,可直接实现短程硝化;海水盐度是实现短程硝化的影响因素之一.     

螺纹桩在软弱地层中的应用

分析了螺纹桩的受力机理,探讨了螺纹桩单桩承载力的确定方法,指出螺纹桩单桩承载力高、节约材料显著、能充分利用地基土的特性,在软弱地层中的应用优势显著,并通过实际工程实例给予具体说明.     

静压挤密桩在湿险性黄土地基处理中的应用

为了解决水泥土挤密桩施工过程中噪音过大的问题,提出了地基处理的静压挤密桩施工法,并结合工程实际测试了静压挤密桩在湿险性黄土地基处理中应用的效果.测试结果表明,该方法在施工时噪音较小,施工速度高,满足设计要求,此为该地基处理方法的应用和推广提供了依据.     

丰田召回启示录

全球范围丰田八种类型860万辆汽车被召回,引发世界媒体高度关注。丰田代表了21世纪管理趋势,不曾想丰田神话,最后竟然是由丰田自己打破。丰田“召回门”的警示将对所有企业产生深远影响。争抢世界第一,代价有时很昂贵;过分关注成本,产品质量难保证;及时化解危机,态度比技术更重要;美国不想第二,竞争变得很复杂。     

满族服饰文化中的灵物崇拜

文章通过对满族萨满文化的宗教信仰和灵物崇拜的研究,从满族人民的精神文化领域揭示满族服饰的意义,以便更好的传承满族服饰,让满族服饰文化源远流长。