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611.
612.
Effects of experimental protocol on global vegetation model accuracy: A comparison of simulated and observed vegetation patterns for Asia 总被引:1,自引:0,他引:1
Prognostic vegetation models have been widely used to study the interactions between environmental change and biological systems. This study examines the sensitivity of vegetation model simulations to: (i) the selection of input climatologies representing different time periods and their associated atmospheric CO2 concentrations, (ii) the choice of observed vegetation data for evaluating the model results, and (iii) the methods used to compare simulated and observed vegetation. We use vegetation simulated for Asia by the equilibrium vegetation model BIOME4 as a typical example of vegetation model output. BIOME4 was run using 19 different climatologies and their associated atmospheric CO2 concentrations. The Kappa statistic, Fuzzy Kappa statistic and a newly developed map-comparison method, the Nomad index, were used to quantify the agreement between the biomes simulated under each scenario and the observed vegetation from three different global land- and tree-cover data sets: the global Potential Natural Vegetation data set (PNV), the Global Land Cover Characteristics data set (GLCC), and the Global Land Cover Facility data set (GLCF). The results indicate that the 30-year mean climatology (and its associated atmospheric CO2 concentration) for the time period immediately preceding the collection date of the observed vegetation data produce the most accurate vegetation simulations when compared with all three observed vegetation data sets. The study also indicates that the BIOME4-simulated vegetation for Asia more closely matches the PNV data than the other two observed vegetation data sets. Given the same observed data, the accuracy assessments of the BIOME4 simulations made using the Kappa, Fuzzy Kappa and Nomad index map-comparison methods agree well when the compared vegetation types consist of a large number of spatially continuous grid cells. The results of this analysis can assist model users in designing experimental protocols for simulating vegetation. 相似文献
613.
不同类型绿地对南京热岛效应的缓解作用 总被引:7,自引:1,他引:6
通过研究南京市区林地、有行道树的道路、草坪地、水泥地面篮球场4种城市土地利用类型的气温、空气相对湿度、太阳辐射强度、地面辐射强度和地表温度等因子,比较了不同类型绿地对城市热岛效应的缓解作用.结果表明,在夏季,悬铃木(Platanus acerifolia willd)、水杉(Metasequoia glyptostroboides Hu et Cheng)、薄壳山核桃(Carya illinoensis K.Koch)行道树以及马褂木(Liriodendron chinense ×L.tulipifera)林能有效阻止阳光直射,太阳辐射强度明显低于篮球场和马尼拉草坪(Zoysia matrella L.Merr);地面辐射强度、地表温度和气温从高到低依次为篮球场,草坪,行道树,马褂木林;而空气相对湿度则表现出相反的趋势;从热岛效应的缓解效果看,树林最强,行道树次之,草坪较弱. 相似文献
614.
Nanqi Ren Wanqian Guo Bingfeng Liu Guangli Cao Jing Tang 《Frontiers of Environmental Science & Engineering》2009,3(4):375-379
Biological hydrogen production by dark fermentation is an important part of biological hydrogen production technologies. China is a typical developing country that heavily relies on fossil fuels; thus, new, clean, and sustainable energy development turns quite urgent. It is delightful that Chinese government has already drawn up several H2 development policies since 1990s and provided financial aid to launch some H2 development projects. In this paper, the research status on dark fermentative hydrogen production in China was summarized and analyzed. Subsequently, several new findings and achievements, with some of which transformed into scale-up tests, were highlighted. Moreover, some prospecting coupling processes with dark fermentation of hydrogen production were also proposed to attract more research interests in the future. 相似文献
615.
Along with the rapid increase in both production and use of TV sets in China, there is an increasing awareness of the environmental impacts related to the accelerating mass production, electricity use, and waste management of these sets. This paper aims to describe the application of life cycle assessment (LCA) to investigate the environmental performance of Chinese TV sets. An assessment of the TV set device (focusing on the Cathode Ray Tube (CRT) monitor) was carried out using a detailed modular LCA based on the international standards of the ISO 14040 series. The LCA was constructed using SimaPro software version 7.2 and expressed with the Eco-indicator' 99 life cycle impact assessment method. For a sensitivity analysis of the overall LCA results, the CML method was used in order to estimate the influence of the choice of the assessment method on the results. Life cycle inventory information was compiled by Ecoinvent 2.2 databases, combined with literature and field investigations on the current Chinese situation. The established LCA study shows that the use stage of such devices has the highest environmental impact, followed by the manufacturing stage. In the manufacturing stage, the CRT and the Printed Circuit Board (PCB) are those components contributing the most environmental impacts. During the use phase, the environmental impacts are due entirely to the methods of electricity generation used to run them, since no other aspects were taken into account for this phase. The final processing step-the end-of-life stage-can lead to a clear environmental benefit when the TV sets are processed through the formal dismantling enterprises in China. 相似文献
616.
617.
危险废物回转窑焚烧系统的工艺设计 总被引:4,自引:0,他引:4
介绍杭州市危险废物回转窑焚烧处理示范工程的一期规模、工艺流程及主要设备的设计方法。 相似文献
618.
中国西部本底大气中CO的连续测量 总被引:16,自引:2,他引:14
在中国西北部的瓦里关全球基准站(36°17'N,100°54'E,3810m asl)建立了气相色谱-汞置换法大气CO连续测量系统.组装调试和运行标定表明,色谱方法的基线稳定,分离度高,检测方法可靠,系统具有高自动化的操作性能和严格的质量控制,其设计完全符合世界气象组织(WMO)全球大气本底测量的要求.根据采样现场大气CO浓度的变化,采用经国际比对的CO标准气系列,用峰高外标法设定可调整的标准工作曲线计算环境CO浓度,系统对CO的检测限低至1×10-9(V/V),检测精度小于0.1%,准确度在±0.05%以内,可提供我国本底地区近地层大气CO连续而精确的现场测量结果. 相似文献
619.
区域高时空分辨率VOC天然源排放清单的建立 总被引:20,自引:9,他引:11
将中尺度气象模式MM5应用于估算VOC天然源排放的研究,建立了高时空分辨率VOC天然源排放清单的估算方法.根据方法需要,确定了我国部分树木排放异戊二烯和萜烯的标准排放因子,各植被类型排放各种VOC的标准排放因子,以及各植被类型季节平均的叶生物量密度.应用该方法估算了华南地区满足区域空气质量数值模拟要求的高时空分辨率VOC天然源排放清单.结果表明,华南地区夏季典型日的VOC天然源排放总量约1.12×104t,VOC排放速率具有明显的时空分布,其中地理分布取决于植被类型及其分布,日变化规律则依赖于太阳辐射和温度的高低.并讨论了VOC天然源排放估算过程中误差的来源 相似文献
620.