水动力条件对全程自养脱氮工艺启动研究

CANON工艺需要部分短程硝化提供亚硝酸盐,所以CANON工艺存在溶解氧难控制的问题,特别是在反应器较小的情况。本文采用设有挡板的改良SBR,通过机械搅拌形成剧烈水流搅动,精确控制溶解氧,研究了不同搅拌速率对CANON工艺启动的影响。结果表明,机械曝气能成功启动了CANON工艺,且获得平均总氮去除率达79.40%,剪切应力的提高有利于脱氮性能的提升,机械曝气启动方式相比于鼓风曝气更加容易控制。     

CuNiIn 微动磨损涂层失效机理研究

目的系统研究CuNiIn和CuInO_2的晶体结构、体模量、剪切模量、杨氏模量、泊松系数、韧性、热膨胀系数、残余应力等物理参量,阐明CuNiIn涂层中生成的其他复合化合物—CuInO_2对CuNiIn机械性能的影响作用机制。方法采用基于密度泛函理论的第一原理,弹性常数采用应力-应变方案,体模量、剪切模量、杨氏模量采用Voigt-Reuss-Hill方法计算。结果CuNiIn和CuInO_2均为机械稳定结构,CuNiIn和CuInO_2的体模量、剪切模量、杨氏模量、泊松系数分别为118.2GPa,13.7GPa,39.6GPa,0.44和119.0GPa,36.8GPa,100.1GPa,0.36。化合物CuInO_2的机械模量较CuNiIn高,韧性较差,热膨胀系数较低,涂层的残余应力较高。结论喷涂工艺不适,或CuNiIn涂层服役过程中生成的CuInO_2对微动磨损CuNiIn涂层服役性能有不利影响。     

火炮机械系统可靠性强化试验方案探讨

目的尝试将可靠性强化试验理论引入其可靠性研究中,提高火炮机械系统的可靠性。方法首先分析可靠性强化试验的发展动态及其应用于机械系统的必要性,而后在对其理论依据进行分析的基础上,明确火炮机械系统可靠性强化试验研究的目的。结果依据火炮机械系统的主要失效模式,制定了包含机械工作原理分析等7个步骤的可靠性强化试验方案,详细分析了各环节的内容及作用。结论研究结果为可靠性强化试验在火炮机械系统中的应用提供一定理论支撑。     

地铁车厢机械排烟和细水雾耦合灭火效果研究

采用火灾动力学软件FDS（FireDynamicSimulator），以封闭单节地铁列车车厢为研究对象，模拟分析不同喷雾速度、排烟量以及排烟启动时刻条件下，车厢内火灾热释放速率、烟气层高度、烟气层温度的变化规律，对细水雾和机械排烟耦合作用下地铁列车车厢火灾灭火效果展升研究。结果表明，喷雾初速度较小时，细水雾动作之后启动排烟系统的灭火效果更好；喷雾初速度较大时，细水雾动作之前启动排烟系统的灭火效果更好；同样的喷雾初速度条件下，增大排烟量町以提高烟气层高度和降低烟气层温度，排烟量过大可能造成火焰区的扰动，降低细水雾的火火效果。     

生石灰强化机械通风法修复三氯乙烯污染土壤

机械通风法是一种操作简单、效果好、成本低的土壤修复技术,特别适合大型挥发性有机化合物(VOC)污染场地的土壤修复,但在环境温度低、土壤含水率高、土壤黏性大等情况下,其修复效果和修复周期会受到极大影响,且土壤中高浓度的污染物残留将严重影响场地修复目标的实现。为了解决这一问题,采用了在土壤中添加一定量生石灰的强化措施。结果表明:(1)生石灰可以显著提高机械通风法修复三氯乙烯(TCE)污染土壤的效果,缩短修复周期,降低污染物在土壤中的残留浓度。(2)生石灰对TCE的强化作用与生石灰的添加量和土壤类型有关,粉质黏土的强化效果要好于粉土和细砂,生石灰添加量越多,强化效果越好;(3)生石灰强化处理TCE的主要机制是提高土壤温度、降低土壤含水率、增加土壤通透性,促进土壤中TCE的解吸和挥发。     

LCA of local strategies for energy recovery from waste in England, applied to a large municipal flow

An intense waste management (WM) planning activity is currently undergoing in England to build the infrastructure necessary to treat residual wastes, increase recycling levels and the recovery of energy from waste. From the analyses of local WM strategic and planning documents we have identified the emerging of three different energy recovery strategies: established combustion of residual waste; pre-treatment of residual waste and energy recovery from Solid Recovered Fuel in a dedicated plant, usually assumed to be a gasifier; pre-treatment of residual waste and reliance on the market to accept the ‘fuel from waste’ so produced. Each energy recovery strategy will result in a different solution in terms of the technology selected; moreover, on the basis of the favoured solution, the total number, scale and location of thermal treatment plants built in England will dramatically change. To support the evaluation and comparison of these three WM strategy in terms of global environmental impacts, energy recovery possibilities and performance with respect to changing ‘fuel from waste’ market conditions, the LCA comparison of eight alternative WM scenarios for a real case study dealing with a large flow of municipal wastes was performed with the modelling tool WRATE. The large flow of waste modelled allowed to formulate and assess realistic alternative WM scenarios and to design infrastructural systems which are likely to correspond to those submitted for approval to the local authorities. The results show that all alternative scenarios contribute to saving abiotic resources and reducing global warming potential. Particularly relevant to the current English debate, the performance of a scenario was shown to depend not from the thermal treatment technology but from a combination of parameters, among which most relevant are the efficiency of energy recovery processes (both electricity and heat) and the calorific value of residual waste and pre-treated material. The contribution and relative importance of recycling and treatment/recovery processes change with the impact category. The lack of reprocessing plants in the area of the case study has shown the relevance of transport distances for recyclate material in reducing the efficiency of a WM system. Highly relevant to the current English WM infrastructural debate, these results for the first time highlight the risk of a significant reduction in the energy that could be recovered by local WM strategies relying only on the market to dispose of the ‘fuel from waste’ in a non dedicated plant in the case that the SRF had to be sent to landfill for lack of treatment capacity.     

典型危险废物的工程力学特性

掌握填埋废物的工程力学特性是确保危险废物填埋堆体稳定性的重要前提条件,因此,针对6种典型危险废物的工程力学特性开展了调查研究.研究结果表明,污泥类危险废物的含水率和有机质含量远高于非污泥类危险废物,而前者的比重则显著低于后者.污泥类危险废物的渗透系数相对较小,比污染土壤和飞灰炉渣混合物的渗透系数小1个数量级,比滤池填料的渗透系数小2个数量级.不同危险废物的无侧限抗压强度排序为:飞灰炉渣混合物(314.3 kPa)和滤池填料(278.9 kPa)＞污染土壤(124.9 kPa)＞杭州氧气厂污泥(68.6 kPa)、锌铬污泥(71.4 kPa)、油泥(58.4 kPa).不同危险废物的粘聚力排序为:飞灰炉渣混合物(40.8 kPa)、滤池填料(31.1 kPa)＞污染土壤(20.9 kPa)＞杭州氧气厂污泥(1.94kPa)、锌铬污泥(3.10 kPa)、油泥(1.81 kPa).此外,不同危险废物的内摩擦角差异相对较小,其变化范围在18.8°～35.0°之间.综合分析可知,飞灰炉渣混合物和滤池填料的工程力学特性较好,而污泥类危险废物的工程力学特性则较差.     

航空结构材料环境适应性研究进展及发展方向

对航空结构材料环境适应性研究进展进行了综述,其中包括新型航空材料的环境适应性研究和环境-力学因素耦合作用对航空结构材料环境适应性的影响,最后阐述了环境适应性研究的结构化趋势,并指出了航空结构材料环境适应性研究未来将重点关注户内加速试验技术、环境适应性评价技术以及环境适应性数据的深度开发与应用,将各种科学技术和工程实践用于减缓环境对结构材料的损伤,提高装备的耐环境能力。     

废橡胶粉对混合砂浆性能影响的研究

系统测试和分析了新拌混合砂浆和易性和硬化砂浆轴心抗压强度、静力受压弹性模量、泊松比、干表观密度、导热系数、干燥收缩率随三元乙丙(EPDM)橡胶粉代砂体积分数增加的变化程度和规律.橡胶粉可以改善新拌混合砂浆的和易性,降低硬化混合砂浆强度、弹性模量、表观密度和导热系数,提高其泊松比和干燥收缩率.低弹性模量、高泊松比、高干缩值橡胶粉混合砂浆将使其更能适应新型墙体材料性能的要求,有利于减小墙体裂缝的产生;低表观密度、低导热系数橡胶粉混合砂浆将有利于提高墙体的隔热保温性能.     

EFFICACY AND COST OF AQUATIC WEED CONTROL IN SMALL PONDS'

ABSTRACT: Twenty, 0.2 hectare ponds were utilized for a four-year evaluation of three aquatic vegetation control techniques: a combination of inorganic fertilization and mechanical harvesting, aquatic herbicides, and grass carp (Ctenopharyngodon idella). Ponds used for herbicide and grass carp treatments were managed at three levels of aquatic vegetation (none, 40 and 70 percent plant occupation). Submersed vegetation was not controlled with inorganic fertilization. Vegetation levels were maintained for less than 30 days after mechanicai harvesting. Submersed macrophytes were not completely eliminated with herbicides, but the herbicide treatments utilized were effective at maintaining aquatic vegetation above 30 percent pond volume occupation. Grass carp consumed all species of submersed vegetation at the stocking densities used in this study; therefore, planned levels of submersed macrophytes were not maintained. Grass carp did not consume all floating leaf vegetation, but after four years some grass carp ponds did have lower densities of floating leaf plants. Fertilization costs were $608/hectare/year, and mechanical harvesting costs were $1979/hectare/year, resulting in a total aquatic vegetation treatment cost of $2587/hectare/ year. Herbicide costs for the different treatment levels ranged from $417/hectare/year to $1339/hectare/year over the four-year period. Grass carp were the most economical vegetation control measure tested, with costs ranging from $159/hectare/year to $248/hectare/year for the four-year study.