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151.
This study elicits individual risk preferences in the context of an infectious disease using choice experiments. A main objective is to examine scope sensitivity using a novel approach. Our results suggest that the value of a mortality risk reduction (VSL) is highly sensitive to the survey design. Our results cast doubt on the standard scope sensitivity tests in choice experiments, but also on the validity and reliability of VSL estimates based on stated-preference studies in general. This is important due to the large empirical literature on non-market evaluation and the elicited values’ central role in policy making.  相似文献   
152.
微量金属强化餐厨垃圾厌氧消化优化条件研究   总被引:1,自引:0,他引:1  
采用L9(34)正交试验,研究了CoCl2·6H2O、FeCl2 ·4H2O及NiCl2·6H2O投加量对餐厨垃圾厌氧消化总固体(TS)、挥发性固体(VS)和COD减量及累积产气量的影响,确定了三因素的主次顺序及最优工艺条件.结果表明,当CoCl2·6H2O、FeCl2·4H2O及NiCl2·6H2O的投加量分别为0.1 mg/(L·d)、1 mg/(L·d)和0.4 mg/(L·d)时,餐厨垃圾厌氧消化减量及产气效果均最优.在此条件下,经过25 d单相厌氧消化,餐厨垃圾厌氧消化TS、VS、COD的去除率及累积产气量分别达到46.04%、61.02%、58.24%和27 433 mL/L,比不投加微量金属的处理分别高16.98%、28.12%、27.84%和48.63%.Co、Fe和Ni的投加量对餐厨垃圾厌氧消化TS、VS和COD去除率及累积产气量均有显著影响,其中Co的影响达到极显著水平;Co、Fe和Ni对餐厨垃圾厌氧消化减量及产气效率影响的主次顺序及显著性从大到小均为Co、Ni、Fe.  相似文献   
153.
探索适宜厚朴(Magnolia officinalis)简单重复序列(simple sequence repeat,SSR)-聚合酶链式反应(polymerase chain reaction,PCR)的最佳条件.在SSR引物筛选基础上,利用正交试验设计对影响PCR反应的5个因素(模板DNA、引物、Mg2+、dNTPs和Taq酶催化活性浓度)进行4个水平的优化,并通过温度梯度试验优化引物退火温度.在厚朴及其近缘物种的70对引物中,筛选出13对扩增条带清晰、多态性丰富的SSR引物.PCR各因素在不同水平下对反应体系的影响由大到小依次为引物浓度、Taq酶催化活性浓度、Mg2+浓度、dNTPs浓度和模板DNA浓度.PCR最佳优化体系:25 μL体系中,模板DNA质量浓度为2 ng·μL-1,引物浓度为0.6μmol·L-1,Mg2+浓度为2.0 mmol·L-1,dNTPs浓度为0.5 mmol·L-1,Taq酶催化活性浓度为0.03 U·μL-1(1U=16.67 nkat).最佳扩增程序:94℃预变性4 min,94℃变性30 s,48.0~59.0℃(退火温度随引物不同而定)退火30 s,72℃延伸1 min,35个循环后72℃延伸10 min.上述结果可为利用SSR-PCR技术研究濒危厚朴群体遗传学和分子生态学提供技术参数.  相似文献   
154.
生物活性炭吸附石化二级废水有机污染物实验主要包括生物活性炭挂膜实验和生物活性碳影响因素实验。在实验中考察了水力负荷和活性炭滤层厚度两因素对有机污染物吸附作用。结果表明:在45 d左右挂膜基本成功,最佳水力负荷为0.25~0.75m3/(m2·h),活性炭滤层最佳厚度为90cm。  相似文献   
155.
加速并行遗传算法及其在暴雨强度公式参数优化中的应用   总被引:1,自引:0,他引:1  
针对标准遗传算法中存在早熟收敛、后期收敛速度慢以及解精度低的问题,结合正交试验设计和元胞自动机模型,提出了一种改进的遗传算法--加速并行遗传算法(APGA).APGA利用正交试验设计确定较好的初始种群,利用元胞自动机模型固有的并行计算能力设计并行遗传算法,借助元胞信息的动态性和多元性实现正交加速过程.该方法不仅能加快遗传算法的收敛速度,而且能提高遗传算法的搜索效率和解的精度,适用于求解复杂的非线性优化问题.APGA用于暴雨强度公式参数的优化实例结果表明,该算法是有效和可行的.  相似文献   
156.
Stalking (deer hunting) is an important land use and activity in the Scottish Highlands, and deer managers have traditionally maintained large numbers of female deer in order to supply a guaranteed number of stags for stalking. Unfortunately, grazing by large numbers of deer conflicts with environmental objectives that are seeking to improve upland habitats and increase the area of native Caledonian Pine forest. This study uses a multi-attribute choice experimental approach to quantify the various characteristics of the stalking experience to determine the value that amateur stalkers attach to the stag numbers, the landscape and other attibutes. Unlike previous applications of stated preference, a large proportion (one-third) of a full factorial design is used to present stalkers with different alternative stalking packages within a postal survey. The results indicate a way forward that could be agreeable to both deer managers and conservationists.  相似文献   
157.
ABSTRACT

Contemporary smart cities have largely mirrored the sustainable development agenda by embracing an ecological modernisation approach to urban development. There is a strong focus on stimulating economic activity and environmental protection with little emphasis on social equity and the human experience. The health and well-being agenda has potential to shift the focus of smart cities to centre on social aims. Through the systematic and widespread application of technologies such as wearable health monitors, the creation of open data platforms for health parameters, and the development of virtual communication between patients and health professionals, the smart city can serve as a means to improve the lives of urban residents. In this article, we present a case study of smart health in Kashiwanoha Smart City in Japan. We explore how the pursuit of greater health and well-being has stretched smart city activities beyond technological innovation to directly impact resident lifestyles and become more socially relevant. Smart health strategies examined include a combination of experiments in monitoring and visualisation, education through information provision, and enticement for behavioural change. Findings suggest that smart cities have great potential to be designed and executed to tackle social problems and realise more sustainable, equitable and liveable cities.  相似文献   
158.
间歇曝气系统中硝酸盐氮负荷对脱氮效率的影响   总被引:1,自引:0,他引:1  
本试验主要考察间歇反应器缺氧阶段硝酸盐氮负荷NNO-x-N(KgNO-x-N/KgMLSSd)对脱氮效率的影响。试验结果表明:在一定水温和BOD5/NOx-N下,NNOx-N负荷对脱氮效率有显著影响。在反应器中采用高浓度污泥是降低NNOx-N的有效途径,有利于反应器脱氮速率VDN(mg/l·min)的提高。此外,通过正交试验得出了在BOD5/NO-x一定时,NNO-x-N、T℃与脱氮效率ηNO-x-N之间的数量关系式  相似文献   
159.
催化电解法处理垃圾渗滤液的研究   总被引:23,自引:1,他引:23  
对垃圾渗滤液的SBR处理出水进行了催化电解的正交实验研究。结果表明 ,其最佳工艺条件 :pH为 8,电极材料为RuO2 IrO2 TiO2 /Ti,电流密度为 1 0A/dm2 ,电极间距为 0 .5cm ,[Cl- 1 ]为 1 0 0 0 0mg/L ,SA /L为 50cm2 /L。在此条件下 ,电解 48min时 ,COD去除率达 82 .6 % ,电流效率为 31 .6 % ,耗电量为 32 .4kwh/t水。  相似文献   
160.
The sediment distributed and insolated under lake was collected for experiments. The nutrient layer distribution conditions of sampled sediment and its physical and chemical characteristics were analyzed to simulate and assess the influence degree to lake water quality. Based on the dynamic water exchanging experiments the nutrient release process in sediment and influence mechanism to substance exchanging on water-sediment interface was studied, and the correlation between the changing content of total phosphors and total nitrogen in sediment and covered water were analyzed for setting up a simulation model. At the same time the influence degree is explained in detail. The experimental results indicated that even if clean water without nutrient contents was used for water exchangement so as to decrease pollution or prevent eutrophication, however owing to the vertical nutrient distribution in lake sediment, it will lead to the increasing release amount greatly especially when the organic nutrient contained in sediment turns into inorganic status because of isolation. Besides the release process of total phosphate (TP) and total nitrogen (TN) were modeled and each nutrient's exchanging equation at interface caused by covered water nutrient concentration changing was set up. According to the simulating prediction, TP and TN content of cover water will also sustain a steady higher level in a long period. The nutrient release amount of sediment is not only affected by the covered water concentration but also connects with accumulative time. The experiments provide the fundamental theoretical and practical basis for taking ecological restoration project. And research is helpful to prevent or restore lake eutrophication.  相似文献   
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