云南省玉龙县碳减排效应估算

玉龙县碳减排效应估算主要包括退耕还林、造林、小水电、替代能源(包括沼气池和太阳能)使用等方面. 其中,造林具有较长期的碳汇功能,会持续提供碳增汇服务功能;替代能源的使用可以有效减少薪柴燃烧,在以农村人口为主的玉龙县,薪柴是主要的取暖和生活能源,故替代能源的使用颇具意义. 以2005年为基准年,小水电和替代能源总的碳减排效应为22.24×103 t,其中小水电碳减排效应为14.43 ×103 t,太阳能碳减排效应为66.24 t,沼气池碳减排效应为7.74×103 t;设定了基准年后林木生长过程以及替代能源使用状况的情景,并进行情景模拟,估算了玉龙县造林在5年内会产生碳汇21.07×103 t,10年内会产生碳汇24.92×103 t. 在研究区总的碳减排效应中,小水电、沼气池以及生态林地都有较大贡献,而经济林和草地的贡献相对较小;与5年情景相比,20年情景中小水电和沼气池的贡献有所上升,而生态林地等的贡献相对下降.      

Fe~0对土壤中3-硝基甲苯的还原作用

研究常温常压下零价铁(ZVI或Fe0)对土壤中3-硝基甲苯(MNT)的还原作用.结果表明:零价铁能够有效地将土壤中的MNT还原为3-甲基苯胺.在MNT为2.5×10-6mol·-1,铁粉加入量为25mg·g-1,土壤初始pH值为6.8,含水量为75%,温度为25℃的条件下,反应5h后MNT的还原率可达95%.随着体系反应时间的延长,温度的升高,土壤含水量的增大和铁粉用量的增加,MNT的还原率均增大.将土壤初始pH值控制在偏酸性有利于反应的进行.     

No reduction in aggression after loss of a broodmate: a test of the brood size hypothesis

In some vertebrate species, parents create a large brood or litter then, in the event of unfavourable ecological conditions, apparently allow the number of offspring to be adaptively reduced through siblicide. But how is sibling aggression regulated so that deaths occur only in unfavourable conditions? One proposed mechanism is brood size-dependent aggression. Two experiments tested for this mechanism by reducing three-chick broods of blue-footed boobies either during or after the period of dominance hierarchy establishment. In neither experiment did aggression of the two eldest and highest ranking chicks decline after removal of the youngest broodmate, in comparison with controls. These results suggest that dominant booby chicks do not become less aggressive to each other after disappearance of their youngest broodmate and that this species does not show brood size dependent aggression. Elder blue-footed booby chicks increase their attacks on broodmates when they receive less food, and this mechanism may be sufficient to tailor brood size to food availability.     

Inherently safer sustained casing pressure testing for well integrity evaluation

This paper presents the use of a model to predict sustained casing pressure (SCP), from early pressure buildup data, as a basis for inherently safer well integrity testing. Inherently safer principles aim to eliminate or reduce the hazards by design rather than by using protective features. SCP, a well integrity issue exhibited in many wells, is any measurable pressure that rebuilds after being bled down and attributable to causes other than artificially applied pressure or temperature fluctuations in the well. Intrusion of gas, resulting in SCP, can occur because of poor cement bond in the casing or cement deterioration. Gas entering the annulus migrates to the wellhead and represents a hazard due to increased wellhead pressure and the gas inventory. Compromised well integrity can have catastrophic consequences on both environmental and safety aspects.Most regulations require the monitoring, testing and, eventually, the elimination of SCP. However, test data analysis is predominantly qualitative and limited to arbitrary criteria. Due to the high percentage of wells that present SCP, accurate, safe and preferably fast testing methods are needed. This paper implements an analytical model, rooted in the transport processes and thermodynamics of the system, to predict pressure profiles and gas accumulation during SCP testing from early-time pressure buildup data. The amount of gas accumulated during different testing criteria, being 1) current practices and 2) early diagnostic by the analytical model, is calculated and compared. Results show that using the analytical model as a predictive tool, testing time is reduced significantly, thereby limiting the amount of gas accumulated and reducing the risk. This makes the testing procedure inherently safer as well as less time consuming.     

工业碳减排绩效及其影响因素动态分解

进入21 世纪以来,中国工业碳排放总量仍在波动中增长。为了考查近10 a 来中国工业碳减排绩效,并定量分析影响工业碳减排的主要因素对碳减排的贡献变化情况,论文通过构建中国工业碳排放数据库并运用“精确”的Laspeyres 分解方法,对中国2001-2010 年36 个工业行业CO₂减排的影响因素进行了动态分解,研究结果表明：①虽然中国工业CO₂排放总量在不断增加,但CO₂排放增长率和工业碳排放强度双双降低,在考察周期内,CO₂排放总量从2001 年 2.89×10⁹ t 增长到2010 年7.16×10⁹ t,工业碳排放量增长率则从2003 年最高值18.86%持续下降至2009 年的5.77%,工业整体碳排放强度由2001 年的29.14 t/104元下降到2010 年的18.12 t/10⁴ 元;②工业经济规模不断增加是工业CO₂排放增加的主导因素,技术进步和结构调整则有效抑制了CO₂的增加,10 a 间规模效应对CO₂排放总量增加的贡献度年均达到191.81%,但是由于受到技术进步效应和结构调整效应的共同作用,10 a 来总效应值年均只有109.15%;③较之技术进步效应,结构调整效应对工业CO₂减排的贡献度更大,结构调整效应累计促进碳减排达2.07× 10⁹ t,而技术进步效应促进减排的总量只有1.14×10⁹ t。论文认为,着力中长期减排政策的制定,以保证技术进步在碳减排中持续发挥作用,同时充分挖掘结构调整对减排作用潜力是中国实现工业碳减排的务实选择。     

基于实测的燃煤电厂氟排放特征

选择我国4家电厂的6台煤粉锅炉,进行了烟气以及飞灰、底渣、脱硫石膏等燃煤副产物样品的采集和F(氟)含量分析,考察燃煤电厂F排放特征. 结果表明:经过烟气除尘、脱硫及脱硝装置后,烟气中氟化物浓度明显降低; 除尘器主要脱除烟气中颗粒态F,静电除尘器对烟气中氟化物的总脱除效率为19.50%~36.59%,布袋除尘器的脱除效率略高于静电除尘器;石灰石-石膏湿法脱硫装置可协同脱除烟气中94.19%的氟化物. 燃煤中的F经过燃烧和烟气净化装置后,有0.83%~3.37%由底渣排放;1.20%~2.00%转移到脱硫废水中;13.45%~33.80%转移到飞灰中;59.60%~79.66%转移到脱硫石膏中;只有2.04%~5.00%通过烟囱排入大气.      

焙烧条件对Ru/AC催化剂去除溴酸盐的影响

考察了以RuCl₃·3H₂O为前驱物,以AC(颗粒活性炭)为载体制备Ru/AC时,焙烧氛围、焙烧温度、焙烧时间对Ru/AC催化活性的影响,并利用XPS(X-ray photoelectron spectra,X射线光电子能谱分析)、BET(brunner-emmet-teller method,比表面积测定)和SEM(scanning electronic microscopy,扫描电镜)等手段对样品进行了表征. 结果表明,不同焙烧氛围中制备的Ru/AC活性有较大差异:在N₂焙烧氛围中,容易形成去除BrO₃-的有效活性组分(RuO₂);而在真空焙烧氛围中,几乎没有活性组分的产生;在H₂-N₂〔φ(H₂)为1.5%,φ(N₂)为98.5%〕氛围中焙烧,负载在AC上的活性组分有Ru₀(单质钌)和RuO₂. 焙烧温度对Ru/AC去除BrO₃-的性能有着较为显著的影响,高温有利于AC的石墨化进程,载体性能得到优化;但焙烧温度过高(1 000 ℃)时,会产生金属颗粒团聚现象;最适宜的焙烧温度为900 ℃. Ru/AC的活性随着焙烧时间的延长呈先增后降的趋势;焙烧时间为3 h时,载体的比表面积和孔容积得到提高且有效活性组分能够均匀地分散在AC载体上. 综上,Ru/AC催化剂的最优焙烧条件:焙烧氛围为N₂,焙烧温度为900 ℃,焙烧时间为3 h. 在该条件下制备的Ru/AC利于形成去除BrO₃-的活性物质RuO₂,并且其能够均匀地分布在AC载体上,使催化反应进行得更为彻底,可在2 h内将BrO₃-全部去除.      

Barriers or enablers? Chiefs,elite capture,disasters, and resettlement in rural Malawi

Chiefs are at the centre of household and community development efforts in most low‐income countries around the world. Yet, researchers and scholars have paid limited attention to the institution of chieftaincy and to understanding its role in the management of climate change adaptation and disaster risk reduction. This paper draws on a micro ethnographic evaluation conducted in two predominantly rural districts of Malawi in southeast Africa to assess two different manifestations of elite control. In the first case, a resettlement programme was implemented where chiefs were co‐opted and took the lead. In the second case, a food insecurity response programme was designed to exclude chiefs. The study finds that neither co‐opting nor countering chiefs prevents elite capture. Rather, the majority of chiefs oscillate between malevolent and benevolent capture. The findings require that states focus on the cultural and political dimensions of rural life when designing climate change adaptation and disaster risk reduction programmes.     

Household self‐blame for disasters: responsibilisation and (un)accountability in decentralised participatory risk governance

The most important theoretical argument concerning decentralised participatory governance is that it can make a government more accountable for the needs of the governed. Key to this process are participatory spaces that act as mechanisms for dialogue between citizens and local government. However, within Cochabamba, a city in the centre of Bolivia, South America, ‘at‐risk’ citizens engage minimally with disaster risk issues in participatory spaces, despite high levels of civic participation. This is because ‘at‐risk’ populations view disasters as a private/household problem that is symptomatic of household error, rather than seeing them as a broader public problem due to wider structural inequalities. Consequently, they redistribute responsibility for disaster risk reduction towards households, which (re)produces the absolution of government authorities as guarantors of disaster risk reduction. This paper challenges the normative assumption that participatory spaces facilitate democratic deliberation of disaster risk reduction and the downward accountability of local government for disaster risk reduction.     

Lessons from seabird conservation in Alaskan longline fisheries

Although bycatch of seabirds and other long-lived species is a critical conservation issue in world fisheries, case studies documenting significant reductions in the mortality of these low-productivity species in a fishery are rare. We studied progress toward seabird conservation in the Alaskan longline fisheries, one of the largest and most diverse demersal fisheries. We generated annual seabird bycatch rates in 4 target fisheries and all fisheries combined from 23 years of fisheries observer data. We used 0-inflated negative binomial models to evaluate variables influencing seabird bycatch per unit effort (BPUE) in 2 target fisheries. Following adoption of streamer lines, at first voluntarily and then mandatorily, seabird BPUE was reduced by 77–90%, preventing mortality of thousands of birds per year. Despite this, BPUE increased significantly in 2 of 4 target fisheries since streamer lines were adopted. Although night setting yielded significant reductions (74–97%) in seabird BPUE and significant increases (7–11%) in fish catch per unit effort over daytime setting, nighttime setting increased the BPUE of Northern Fulmar (Fulmarus glacialis) by 40% and nontarget fish species by 5–17%. Thus, best practices to prevent seabird mortalities in longline fisheries varied by species assemblage and fishery. Our results inform global efforts toward fisheries bycatch reduction by illustrating that successful conservation requires fishery-specific solutions, strong industry support, constant vigilance in analysis and reporting observer data, and ongoing outreach to fleets, especially to vessels with anomalously high BPUE.