Reducing nitrogen runoff from paddy fields with arbuscular mycorrhizal fungi under different fertilizer regimes

Nitrogen(N) runoff from paddy fields serves as one of the main sources of water pollution. Our aim was to reduce N runoff from paddy fields by fertilizer management and inoculation with arbuscular mycorrhizal fungi(AMF). In northeast China, Shuangcheng city in Heilongjiang province, a field experiment was conducted, using rice provided with 0%, 20%, 40%, 60%, 80%,and 100% of the local norm of fertilization(including N, phosphorus and potassium), with or without inoculation with Glomus mosseae. The volume, concentrations of total N(TN),dissolved N(DN) and particulate N(PN) of runoff water were measured. We found that the local norm of fertilization led to 18.9 kg/ha of N runoff during rice growing season, with DN accounting for 60%–70%. We also found that reduction in fertilization by 20% cut down TN runoff by 8.2% while AMF inoculation decreased N runoff at each fertilizer level and this effect was inhibited by high fertilization. The combination of inoculation with AMF and 80% of the local norm of fertilization was observed to reduce N runoff by 27.2%. Conclusively, we suggested that the contribution of AMF inoculation combined with decreasing fertilization should get more attention to slow down water eutrophication by reducing N runoff from paddy fields.     

郑州市水污染物排放现状及分析研究

随着经济的进步,水污染问题日益凸显,水资源短缺越来越严重,这不仅制约了城市的经济、社会、环境的可持续发展,更是对人体健康造成了威胁,为了解郑州市近年来污染物排放状况及对其原因进行分析,本文对近几年污染物排放量进行调查,结果表明污水排放总量逐渐上升,这与人口增加、工农业需水量增加有关;主要限排物质COD、氨氮的排放量总体呈下降趋势,但个别年份出现突增现象,这可能与政府的环保政策改变及个别工业偷排有关,对此本研究提出相适应的建议.     

飞机防火试验中的燃烧反应动力学模型研究

使用反应路径分析法对Jet-A型航空煤油燃烧的气相燃烧机理进行简化。选用POSF-4658机理作为Jet-A燃烧的详细反应机理,该机理包含1607种燃烧组分、6633个基元反应机理。将飞机防火试验条件作为简化过程的初始条件,得到78种组分,196个反应机理的Jet-A燃烧机理。通过对Jet-A的简化反应机理、详细反应机理和JetA实验数据的比较可以发现,简化反应机理可以较准确地反映Jet-A型航空煤油在防火试验条件下的燃烧特性。利用常用的Jet-A型航空煤油简化机理计算的绝热火焰温度、点火延迟时间及层流火焰速度与本文提出的简化的计算值进行比较。结果表明,提出的简化机理在防火试验条件下具有较高的精确度。得到的Jet-A简化反应机理可为飞机防火试验的仿真研究提供燃烧场的化学反应动力学模型。     

A case study on project-level CO2 mitigation costs in industrialised countries: the Climate Cent Foundation in Switzerland

This paper analyses CO₂ emissions reduction costs based on project data from the Climate Cent Foundation (CCF), a climate policy instrument in Switzerland. Four conclusions are drawn. First, for the projects investigated, the CCF on average pays €63/ton. Due to the Kyoto Protocol, the CCF buys reductions only until 2012. This cut-off increases reported per ton reduction costs, as the additional lifetime project costs are set in relation to reductions only until 2012, rather than to reductions realised over the whole lifetime. Lifetime reduction costs are €45/t. Second, correlation between CCF's payments and lifetime reduction costs per ton is low. Projects with low per ton reduction costs should thus be identified based on lifetime per ton reduction costs. Third, the wide range of project costs per ton observed casts doubts on the widely used identification of the merit order of reduction measures based on average per ton costs for technology types. Finally, the CCF covers only a fraction of additional reduction costs. Decisions to take reduction efforts thus depend on additional, non-observable and/or non-economic motives. Any generalisation of results has to consider that this analysis is based on prospective costs of a sub-sample of projects in Switzerland.     

巴黎协定下中国碳排放权省域分配及减排潜力评估研究

通过构建碳排放权区域分配模型完成了省域分配,在此基础上与当前各地实际碳排放量进行比对,明晰了各自初始空间余额;而后对碳排放权欠缺地区的碳减排潜力进行了综合评估。研究结果表明：（1）我国30个省区碳排放权分配存在较大差异,其中云南配额最高,占比高达10.53%;宁夏配额最少,占比仅为0.28%。（2）全国有14个省区碳排放权初始空间余额表现出盈余状态,根据成因差异可大致分为“低排放、高配额”“低排放、低配额”以及“高排放、高配额”等三种类型;其他16个地区均表现出一定程度的欠缺,结合数值差异可划分为以江苏等4地为代表的轻度欠缺地区,以天津等7地为代表的中度欠缺地区,以及以辽宁等5地为代表的重度欠缺地区。（3）浙江、天津、山东等3地目前所具备的碳减排潜力要明显高于其他地区,而各地区的碳减排潜力水平虽与其碳排放权欠缺量表现出了一定趋同性但并非完全一致。     

炼钢厂1号—3号转炉煤气回收实践

针对提钒炼钢厂建设于20世纪70年代初的1号—3号转炉实施煤气回收的可能性进行了论证,对影响煤气回收的问题提出了相应的完善措施,在此基础上成功实施了1号—3号转炉煤气回收改造,改进后年回收转炉煤气达2 127 138GJ以上,可发电59 124 kW.h,减少CO2排放量近20万t,对降低生产能耗及减少温室气体排放起到了较好作用。     

Metrics of progress in the understanding and management of threats to Australian birds

Although evidence-based approaches have become commonplace for determining the success of conservation measures for the management of threatened taxa, there are no standard metrics for assessing progress in research or management. We developed 5 metrics to meet this need for threatened taxa and to quantify the need for further action and effective alleviation of threats. These metrics (research need, research achievement, management need, management achievement, and percent threat reduction) can be aggregated to examine trends for an individual taxon or for threats across multiple taxa. We tested the utility of these metrics by applying them to Australian threatened birds, which appears to be the first time that progress in research and management of threats has been assessed for all threatened taxa in a faunal group at a continental scale. Some research has been conducted on nearly three-quarters of known threats to taxa, and there is a clear understanding of how to alleviate nearly half of the threats with the highest impact. Some management has been attempted on nearly half the threats. Management outcomes ranged from successful trials to complete mitigation of the threat, including for one-third of high-impact threats. Progress in both research and management tended to be greater for taxa that were monitored or occurred on oceanic islands. Predation by cats had the highest potential threat score. However, there has been some success reducing the impact of cat predation, so climate change (particularly drought), now poses the greatest threat to Australian threatened birds. Our results demonstrate the potential for the proposed metrics to encapsulate the major trends in research and management of both threats and threatened taxa and provide a basis for international comparisons of evidence-based conservation science.     

Is asynchronous hatching adaptive in herring gulls (Larus argentatus)?

Hatching asynchrony commonly induces a size hierarchy among siblings and the resultant competition for food between siblings can often lead to starvation of the smallest chicks within a brood. We created herring gull (Larus argentatus) broods with varying degrees of hatching synchrony by manipulating the timing of incubation while maintaining the originally laid eggs. The degree of hatching asynchrony affected sibling size hierarchy at the time of hatching of the last-hatched ”c-chick.” In unmanipulated broods, there was no disadvantage of being a c-chick. However, when asynchrony was experimentally increased, we found reduced survival of the c-chick only in the exaggerated asynchronous experimental group. The effects were observable only during the first 10 days of chick life. We recorded no cases of the chicks dying of starvation. Furthermore, behavioral observations indicated that there was no sibling competition, and no selective feeding of larger sibs in the study colony. We propose that the observed lower survival rates of c-chicks in exaggerated asynchronous broods resulted from their lesser motor abilities, affecting their chances of escaping predators. Fledging success for the whole colony was generally high and almost half of all pairs fledged all three chicks, which is indicative of a good feeding environment. We argue that normal hatching asynchrony is a favorable solution in a good feeding environment, but that increased asynchrony reduces breeding success. We do not view asynchrony in the herring gull as an adaptation for brood reduction and propose instead that it may come about because there has been selection for incubation to start before clutch completion. Received: 14 April 1999 / Received in revised form: 20 October 1999 / Accepted: 23 January 2000     

Changes in biomass activity and characteristics of activated sludge exposed to low ozone dose

In this paper, the response mechanism of activated sludge exposed to low-dose ozone at less than 20 mg O₃ g⁻¹ total suspended solids (TSS) was studied by analyzing the changes in sludge activity and the evolution of C, N, P and metals from sludge following ozonation. The intracellular ATP concentration was not affected at less than 5 mg O₃ g⁻¹ TSS and thereafter decreased rapidly to around 60% when the ozone dose increased to 20 mg O₃ g⁻¹ TSS. Similarly, the efficiency of sludge solubilization initially changed a little and then increased rapidly to around 30% at an ozone dose of 20 mg O₃ g⁻¹ TSS. However, the activities of superoxide dismutase and protease decreased immediately upon exposure to ozone. These findings indicate that ozone firstly destroys the floc, leading to the disruption of the compact aggregates, which does not affect cells viability but induces a decrease in enzyme activities. Ozone then attacks the bacterial cells of the sludge, causing a decrease in cells viability. During ozonation, the content of carbon, nitrogen and phosphorus in the sludge matrix decreased, while the content of these elements in the micro-solids and supernatant gradually increased. Most of the released metals from the sludge matrix were found in the micro-solids.     

我国大气细颗粒物污染防治目标和控制措施研究

我国面临着严重的细颗粒物(PM2.5)污染问题,PM2.5对人体健康、能见度、气候变化、生态系统等均产生了不良影响。本文旨在提出我国PM2.5污染防治目标和控制措施,为从根本上改善空气质量提供科学依据。首先,本文提出了2020年和2030年我国PM2.5污染防治目标。其次,采用能源和污染排放技术模型,分情景预测了我国未来一次大气污染物排放量的变化趋势。基于情景预测结果和此前研究建立的一次污染物排放与PM2.5浓度间的非线性关系,确定了2020年—2030年与PM2.5浓度改善相适应的全国和重点区域大气污染物减排目标。最后,利用能源和污染排放技术模型,提出了实现大气污染物减排的技术措施和对策建议。研究表明,2030年全国二氧化硫、氮氧化物、一次PM2.5和挥发性有机物的排放量应分别比2012年至少削减51%、64%、53%和36%,氨排放量也要略有下降。对于污染严重的重点区域,必须采取更严格的控制力度。要实现上述减排,应加快能源结构调整,推进煤炭清洁高效集中可持续利用,建立"车-油-路"一体的移动源控制体系,并强化多源多污染物的末端控制。