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91.
The forest hydrologic budget may be impacted by increasing CO2 and tropospheric O3. Efficient means to quantify such effects are beneficial. We hypothesized that changes in the balance of canopy interception, stem flow, and through-fall in the presence of elevated CO2 and O3 could be discerned using image analysis of leafless branches. We compared annual stem flow to the results of a computerized analysis of all branches from the 2002, 2004, and 2006 annual growth whorls of 97 ten-year-old trees from the Aspen Free-Air CO2 and O3 Enrichment (Aspen FACE) experiment in Rhinelander, WI. We found significant effects of elevated CO2 and O3 on some branch metrics, and that the branch metrics were useful for predicting stem flow from birch, but not aspen. The results of this study should contribute to development of techniques for efficient characterization of effects on the forest hydrologic budget of increasing CO2 and tropospheric O3. 相似文献
92.
Sally R. Gadsdon Jeremy R. Dagley 《Environmental pollution (Barking, Essex : 1987)》2010,158(8):2553-2560
The relationship between different features of lichen communities in Quercus robur canopies and environmental variables, including concentrations of NO2 and NH3 was investigated. NO2 concentration was the most significant variable, it was positively correlated with the proportion of lichen cover comprising nitrophytes and negatively correlated with total lichen cover. None of the lichen community features were correlated with NH3 concentrations, which were relatively low across the site. Since nitrophytes and nitrophobes are likely to react in opposite directions to nitrogenous compounds, total lichen cover is not a suitable indicator for these pollutants. It is, therefore, suggested that the proportion of lichen cover comprising nitrophytes may be a suitable simple indicator of air quality, particularly in locations where the pollution climate is dominated by oxides of nitrogen. 相似文献
93.
在未来相当长的一段时间内,煤气化仍是大规模制取氢气的主要途径。目前,常规煤气化过程得到的是H2、CO和CO2为主的混合气,需要通过净化、变换和分离工艺才能得到洁净的氢气,工艺过程复杂。采用连续式超临界水反应装置,以质量分数为20%的水煤浆为反应原料,考察了Ca/C摩尔比和温度对褐煤制氢系统的影响。试验结果表明:Ca(OH)2不仅可以很好地固定气相中的CO2和硫化物,而且对煤气化过程也表现出较好的催化作用。反应温度600℃,压力为25MPa的条件下,与未加Ca(OH)2相比,Ca/C摩尔比为0.45时,气体中CO2的体积分数由50.7%降至1.0%,趋于完全固定;硫化物浓度由10 878mg/m3降至807mg/m3;H2的体积分数由32.4%增至73.3%。Ca(OH)2对煤气化的催化作用在高温下更加明显。 相似文献
94.
95.
为满足石油化工企业总量控制的要求,采取相应的治理措施,降低污染物排放总量,避免采取大量投资和占地的末端治理措施,在工艺过程中采取措施降低主要污染物排放总量是行之有效的途径,采用催化工艺中添加硫转移脱氮剂的办法、热电厂锅炉采用改善炉体燃烧状态、配合石灰石脱硫等工艺过程措施,探讨进一步减少二氧化硫排放总量的可行性。 相似文献
96.
Emma Ter Mors Mieneke W.H. Weenig Naomi Ellemers Dancker D.L. Daamen 《Journal of environmental psychology》2010,30(4):347-357
This experimental research addresses the effectiveness of communication about complex environmental issues, depending on whether the same information is provided by multiple collaborating or by individual organizations (i.e., stakeholders). The information provided pertains to carbon dioxide capture and storage (CCS) technology, as an example of a complex environmental issue. In Studies 1 (N = 75) and 2 (N = 66) we found that participants perceived factual information from collaborating stakeholders to be of higher quality than when the same information was provided by individual stakeholders. As predicted, the expectation of diverse perspectives being represented in the collaborative information mediated this effect. In addition, in Study 3 (N = 79) the perceived dissimilarity of collaborating stakeholders was shown to be an important precondition for the collaboration effect observed in Studies 1 and 2. Finally, these studies indicate that occasional collaboration between different stakeholders does not necessarily harm the perceived credibility of each individual stakeholder. 相似文献
97.
Kelly K. Moran Julie D. Jastrow 《Environmental pollution (Barking, Essex : 1987)》2010,158(4):1088-1094
The potential for storing additional C in U.S. Corn Belt soils - to offset rising atmospheric [CO2] - is large. Long-term cultivation has depleted substantial soil organic matter (SOM) stocks that once existed in the region's native ecosystems. In central Illinois, free-air CO2 enrichment technology was used to investigate the effects of elevated [CO2] on SOM pools in a conservation tilled corn-soybean rotation. After 5 and 6 y of CO2 enrichment, we investigated the distribution of C and N among soil fractions with varying ability to protect SOM from rapid decomposition. None of the isolated C or N pools, or bulk-soil C or N, was affected by CO2 treatment. However, the site has lost soil C and N, largely from unprotected pools, regardless of CO2 treatment since the experiment began. These findings suggest management practices have affected soil C and N stocks and dynamics more than the increased inputs from CO2-stimulated photosynthesis. 相似文献
98.
HCl是城市垃圾焚烧产生的主要气体污染物之一。将一种新型脱氯剂TiO2引入到垃圾焚烧系统中,并与其他脱氯剂的性能进行比较。研究了不同脱氯剂使用量、不同反应温度和不同HCl气体浓度对TiO2、CaO和CaTiO3脱氯效果的影响。结果显示,TiO2能在高温(800~1 000℃)、高HCl浓度(1 303.6~1 629.5 mg/m3)下获得较好的脱氯效果。与传统的脱氯剂CaO相比,TiO2更适合于高温烟气脱氯,其在1 000℃时的氯容(36.3 mg HCl/g TiO2)几乎是相同情况下的CaO氯容(9.3 mg HCl/g CaO)的4倍。而CaTiO3的脱氯效果不但受到自身分解效率的影响,还受到TiO2和CaO脱氯效果的影响,其脱氯效果较差。 相似文献
99.
利用高压塑片法制备掺杂镧和活性炭以及聚四氟乙烯(PTFE)的新型二氧化铅电极,采用X衍射(XRD),循环伏安曲线(CV),扫描电镜(SEM)等手段对电极性能进行表征,研究了其电催化处理有机染料废水(亚甲基蓝)的降解效果,并对反应机理进行了相关研究。研究表明,该电极具有良好的抗腐蚀能力,对亚甲基蓝具有较好的降解效果。通过与普通二氧化铅电极比较,该电极在染料脱色和去除COD方面都有较明显优势,显示出较好的工业应用前景。 相似文献
100.
采用溶胶-凝胶法制备了活性炭纤维负载TiO2催化剂(TiO2/ACF),并通过SEM和XRD等手段对TiO2/ACF进行了表征。以邻苯二甲酸二甲酯(DMP)为目标降解物,考察了催化材料的电催化活性。实验结果表明:在反应温度为25 ℃、初始DMP质量浓度为100.0 mg/L、电解质Na2SO4质量浓度为100 mg/L、电流密度为62.5 mA/cm2、电极板间距为4 cm的条件下,经过40 min的降解,DMP质量浓度为1.8 mg/L,DMP去除率为98.2%;TiO2/ACF在反应过程中可以原位再生,经6次重复使用后仍保持很高的催化活性,对DMP的去除率仍达90%以上。 相似文献