碳交易背景下天津市电力行业碳排放强度与基准线

电力行业是我国碳排放权交易体系中的重要参与行业,开展区域电力行业碳排放强度分析与基准线设置研究,不仅有利于区域因地制宜地开展行业碳减排工作,同时对全国统一碳市场的建立尤其是电力行业配额分配方案的确定具有重要参考价值.基于天津市2014年15家主要发电企业的32台发电机组数据,在核算分析天津市电力行业碳排放强度的基础上,设置实际排放情景、现行标准先进值情景及综合减排情景等3组基准线情景,并展开对天津市电力行业碳减排的适用性分析.研究表明:①在数据和统计基础较好、产品单一的行业采用基准法进行配额分配,有利于碳市场资源的公平、合理配置,可有效促进区域电力行业低碳发展;②2014年天津市电力行业碳排放强度为822.9 g/（kW·h）,燃煤发电与燃气发电碳排放强度分别为824.4与502.0 g/（kW·h）;③发电碳排放强度可反应出单台机组的能耗和管理水平,燃煤发电方式下,采用压力参数高、机组容量大的机组发电更有利于降低区域碳强度;④综合减排情景既考虑了本地区电力行业碳排放水平,同时参考了其他省市基准线设定,对部分类型机组数量较少、代表性不足的地区适用性更强,该情景对地区电力行业低碳水平要求最为严格,虽然为企业减排带来一定压力,但更有利于区域行业减排,且对于排放强度较高的较小容量机组能够起到更强的激励作用.      

Extra-pair paternity, offspring mortality and offspring sex ratio in the socially monogamous coal tit (Parus ater)

Females of many socially monogamous bird species commonly engage in extra-pair copulations. Assuming that extra-pair males are more attractive than the females’ social partners and that attractiveness has a heritable component, sex allocation theory predicts facultative overproduction of sons among extra-pair offspring (EPO) as sons benefit more than daughters from inheriting their father’s attractiveness traits. Here, we present a large-scale, three-year study on sex ratio variation in a passerine bird, the coal tit (Parus ater). Molecular sexing in combination with paternity analysis revealed no evidence for a male-bias in EPO sex ratios compared to their within-pair maternal half-siblings. Our main conclusion, therefore, is that facultative sex allocation to EPO is absent in the coal tit, in accordance with findings in several other species. Either there is no net selection for a deviation from random sex ratio variation (e.g. because extra-pair mating may serve goals different from striving for ‘attractiveness genes’) or evolutionary constraints preclude the evolution of precise maternal sex ratio adjustment. It is interesting to note that, however, we found broods without EPO as well as broods without mortality to be relatively female-biased compared to broods with EPO and mortality, respectively. We were unable to identify any environmental or parental variable to co-vary with brood sex ratios. There was no significant repeatability of sex ratios in consecutive broods of individual females that would hint at some idiosyncratic maternal sex ratio adjustment. Further research is needed to resolve the biological significance of the correlation between brood sex ratios and extra-pair paternity and mortality incidence, respectively.     

Paternity covaries with laying and hatching order in the collared flycatcher Ficedula albicollis

Females in most bird species engage in extra-pair copulations. Although this behaviour is widespread, benefits for females of doing so are less understood. The most widely accepted hypothesis is that they improve their previous choice of social partner and gain genetic benefits for their offspring. Some evidence for this comes from studies that find that extra-pair young (EPY) have greater fitness than their half-sibs. However, this might be also caused by maternal, non-genetic effect, a possibility that remains largely untested. Here we test whether EPY are laid in larger eggs or eggs laid early in the laying sequence in the collared flycatcher (Ficedula albicollis). The size of eggs bearing EPY and within-pair young (WPY) did not differ, however, EPY were laid in early eggs and consequently hatched earlier than WPY. As hatching asynchrony is a strong determinant of offspring size and survival in many species, including collared flycatcher, our results suggest that a caution is needed when paternal genetic effects are to be inferred from comparison of naturally occurring half-sibs.     

On ranked set sampling for multiple characteristics

We consider the selection of samples in ranked set sampling when several attributes of each sample are of interest. We describe approaches that have appeared previously in the literature and present a novel method that seeks to achieve samples that are nearly balanced with respect to the ranks of all attributes. This method is shown to result in very little loss of precision compared to problems in which only a single sample attribute is of interest.     

Earlier sex change in infected individuals of the protogynous reef fish<Emphasis Type="Italic"> Thalassoma bifasciatum</Emphasis>

Sex allocation theory for sequential hermaphrodites predicts the size at which an individual should change sex, given the different relationships between individual size and reproductive success in the two sexes. We studied a host-parasite system where the myxozoan Kudoa ovivora infects the ovaries of the reef fish Thalassoma bifasciatum, a protogynous sequential hermaphrodite. The parasite sporulates in the hosts eggs and renders them infertile. It is thus expected to reduce the females reproductive success, and could thereby influence host sex change. We present data from marked fish we observed in the field over 4 months. The data suggest that females infected with Kudoa ovivora have a lower reproductive success, change sex earlier and at a smaller size than uninfected females. These results are in agreement with predictions from sex allocation theory, and provide the first example of a possible parasitic influence on the sex allocation of its host.Communicated by P. Heeb     

河流环境关心点的位置定量化

提出了河流环境关心点的概念，即指河流两岸或河中体现或影响河流环境功能的环境要素与河流某断面相互作用的点。阐述了河流环境关心点与位置定量化之间的关系及编制点位图时应遵循的功能原则、水质原则和边界原则，指出河流环境关心点位图能够比较直观、全观地反映各点位分布情况。以沅江为例，叙述了绘制各环境关心点位的方法。     

关中地区清洁能源供暖综合效益评价——西安某商业建筑的案例实证

随着中国发展方式转变与能源结构转型的深入推进,能源消耗“双控”与燃煤替代供热清洁化、集中化成为必然趋势。清洁供暖效益评价研究是一个动态的系统性问题,涉及技术、财务、经济和社会评价等方面。目前,有关供热模式评价一般集中在经济和技术视角,难以系统反映经济社会、环境资源等深层次问题。以空气源热泵、燃气锅炉和浅层地热能为主多能互补的供暖方案为评价对象,采用系统评价的方法,基于DPSIR模型构建清洁能源供暖综合效益评价指标体系,利用AHP-POS灰色关联度模型定量评价西安市商业建筑清洁能源供暖方案综合效益和D-P-S-I-R子系统的影响作用。结果表明：在经济、技术和投资环境等条件允许情况下,应优先实施以浅层地热能为主的多能互补供暖方案,依次实施煤改电和煤改气方案。进而提出关中地区清洁能源供暖监管体系对策建议,以供决策者和投资者参考。     

The politics of interbasin transfers: socio‐environmental impacts and actor strategies in Tunisia

Mediterranean wetlands are of key interest in the preservation of biodiversity. However, their ecological water requirement is in constant competition with human uses, particularly in a context of aridity and climate change. This paper examines the case of the Ichkeul Lake‐Lagoon system located in the north of Tunisia in a river basin that is heavily contributing to the water supply of southern regions through water transfers. It maps out the various actors involved, their stakes, discourses and strategies, and explains the current degradation of the Ichkeul system by unpacking the decision‐making power of these actors. It confirms that marginal social groups, ecosystems and next generations are the main parties affected by current water allocation patterns.     

Emissions trading systems with cap adjustments

Emissions Trading Systems (ETSs) with fixed caps lack provisions to address systematic imbalances in the supply and demand of permits due to changes in the state of the regulated economy. We propose a mechanism which adjusts the allocation of permits based on the current bank of permits. The mechanism spans the spectrum between a pure quantity instrument and a pure price instrument. We solve the firms׳ emissions control problem and obtain an explicit dependency between the key policy stringency parameter—the adjustment rate—and the firms׳ abatement and trading strategies. We present an analytical tool for selecting the optimal adjustment rate under both risk-neutrality and risk-aversion, which provides an analytical basis for the regulator׳s choice of a responsive ETS policy.     

Compartmentation of metals in foliage of Populus tremula grown on soils with mixed contamination. I. From the tree crown to leaf cell level

In order to achieve efficient phytoextraction of heavy metals using trees, the metal allocation to aboveground tissues needs to be characterised. In his study, the distribution of heavy metals, macro- and micronutrients and the metal micro-localisation as a function of the leaf position and heavy metal treatment were analysed in poplars grown on soil with mixed metal contamination. Zinc was the most abundant contaminant in both soil and foliage and, together with cadmium, was preferentially accumulated in older foliage whereas excess copper and lead were not translocated. Changes in other element concentrations indicated an acceleration in aging as a consequence of the metal treatment. Excess zinc was irregularly accumulated inside leaf tissues, tended to saturate the veins and was more frequently stored in cell symplast than apoplast. Storage compartments including metabolically safe and sensitive subcellular sites resulted in sizable metal accumulation as well as stress reactions.