Photochemical Behavior of Parathion in the Presence of Humic Acids from Different Origins

This paper reports the effect of ultraviolet radiation on the degradation of pesticide ethyl parathion in the presence of humic acids. Ethyl parathion was completely degraded in 300 min using an artificial lamp of 7.41 × 10^{? 10} einstein/s. Humic acid from peat did not influence the photochemical rate (k = 8.92 × 10^?3 min). However, in the presence of aquatic humic acid, the photochemical rate was higher (11.5 × 10^?3 min). The analytical determinations show the presence of p-nitrophenol and aminophenol in the reaction medium during the photochemical experiments. The kinetic of degradation in all experiments obeyed a first-order reaction pattern.     

一次连续在线观测分析天津市细颗粒物污染特征

根据2005年的5月17日—5月23日GR IMM(1.109#)谱分析仪在线观测结果考察天津市细颗粒物浓度和质量浓度特征。观测期间,天津市颗粒物数浓度平均值为1 124 cm-3,粒径分布为0.25μm~0.60μm,98.5%粒子的粒径0.65μm。同期PM10日均质量浓度值为204μg/m3,ρ(PM2.5)为104μg/m3,ρ(PM1.0)为82.9μg/m3。ρ(PM1.0)/ρ(PM2.5)超过80%,粒径1μm超细颗粒物为天津城市大气颗粒物的主要成分。     

Models to Assess the Risk of Snow and Wind Damage in Pine, Spruce, and Birch Forests in Sweden

3 are damaged annually by snow and wind, roughly corresponding to a value of US$150 million, and in Europe, the damage amounts to hundreds of millions of US dollars each year. To help to reduce these losses, tools for risk assessment within forest management have been developed. Predictions were developed of the risk of damage from snow and wind to Scots pine (Pinus sylvestris L.), Norway spruce [Picea abies (L.) Karst.] and Birch (Betula spp. L.) plots using tree, stand, and site characteristics. The data were obtained from 6756 permanent sample plots within the Swedish National Forest Inventory, which were inventoried twice at five-year intervals between 1983 and 1992. Input data for model development used measurements from the first inventory of tree characteristics for the largest sample tree, stand, and site data, and records of snow and wind damage from the second inventory. Models were developed for three different regions for pine- and spruce-dominated sites, while models for the whole country were developed for birch sites. In general the estimated proportion of damaged plots was highly overestimated (31.7%–56.2%), compared with the observed proportion of 3.4%–11.9%. The models for Norway spruce comprising tree, stand, and site data show the best predictability of damaged plots, with 60.6%–67.6% of plots correctly classified. It is concluded that the models developed can be used to detect sites with a high probability of damage from snow and wind, and thus be used as tools to reduce future damage and costs in practical forestry.     

Quantifying species recovery and conservation success to develop an IUCN Green List of Species

Stopping declines in biodiversity is critically important, but it is only a first step toward achieving more ambitious conservation goals. The absence of an objective and practical definition of species recovery that is applicable across taxonomic groups leads to inconsistent targets in recovery plans and frustrates reporting and maximization of conservation impact. We devised a framework for comprehensively assessing species recovery and conservation success. We propose a definition of a fully recovered species that emphasizes viability, ecological functionality, and representation; and use counterfactual approaches to quantify degree of recovery. This allowed us to calculate a set of 4 conservation metrics that demonstrate impacts of conservation efforts to date (conservation legacy); identify dependence of a species on conservation actions (conservation dependence); quantify expected gains resulting from conservation action in the medium term (conservation gain); and specify requirements to achieve maximum plausible recovery over the long term (recovery potential). These metrics can incentivize the establishment and achievement of ambitious conservation targets. We illustrate their use by applying the framework to a vertebrate, an invertebrate, and a woody and an herbaceous plant. Our approach is a preliminary framework for an International Union for Conservation of Nature (IUCN) Green List of Species, which was mandated by a resolution of IUCN members in 2012. Although there are several challenges in applying our proposed framework to a wide range of species, we believe its further development, implementation, and integration with the IUCN Red List of Threatened Species will help catalyze a positive and ambitious vision for conservation that will drive sustained conservation action.     

Lessons from Białowieża Forest on the history of protection and the world's first reintroduction of a large carnivore

Understanding how the relationships between large carnivores and humans have evolved and have been managed through centuries can provide relevant insights for wildlife conservation. The management history of many large carnivores has followed a similar pattern, from game reserved for nobility, to persecuted pests, to conservation targets. We reconstructed the history of brown bear (Ursus arctos) management in Bia?owie?a Forest (Poland and Belarus) based on a detailed survey of historical literature and Russian archives. From the end of the Middle Ages to the end of 18th century, the brown bear was considered “animalia superiora” (i.e., game exclusively reserved for nobility and protected by law). Bears, also a source of public entertainment, were not regarded as a threat. Effective measures to prevent damages to traditional forest beekeeping were already in practice. In the beginning of 19th century, new game‐management approaches allowed most forest officials to hunt bears, which became the primary target of hunters due to their valuable pelt. This, together with an effective anticarnivore policy enhanced by bounties, led to bear extirpation in 1879. Different approaches to scientific game management appeared (planned extermination of predators and hunting levels that would maintain stable populations), as did the first initiatives to protect bears from cruel treatment in captivity. Bear reintroduction in Bia?owie?a Forest began in 1937 and represented the world's first reintroduction of a large carnivore motivated by conservation goals. The outbreak of World War II spoiled what might have been a successful project; reproduction in the wild was documented for 8 years and bear presence for 13. Soft release of cubs born in captivity inside the forest but freely roaming with minimal human contact proved successful. Release of captive human‐habituated bears, feeding of these bears, and a lack of involvement of local communities were weaknesses of the project. Large carnivores are key components of ecosystem‐function restoration, and site‐specific histories provide important lessons in how to preserve them for the future.     

西安采暖期PM2.5及其水溶性无机离子的时段分布特征

为了探讨西安市采暖期大气颗粒物PM2.5及其水溶性无机成分的污染水平,于2010年1月4日—2月1日按一天8个时段(每个时段3 h)连续采集PM2.5样品四周,每周更换一次滤膜。结果显示,西安市采暖期PM2.5的质量浓度时段差异较大,呈现明显的双峰分布特征:21:00—24:00时段(147.516μg/m3)和09:00—12:00时段(141.678μg/m3)。4种被测水溶性无机组分总浓度为39.801μg/m3,占PM2.5总浓度的30.5%。SO24-和NO3-是最主要组分,占到4种无机组分的86.2%。各离子间相关分析显示,Cl-只与NO3-有较强的相关性,表明机动车尾气对Cl-有较大的贡献。SO24-和NO3-时段分布规律较为相似,与PM2.5浓度的时段分布特征相反:在PM2.5污染最轻的15:00—18:00时段,SO24-和NO3-的相对含量达到一天中的最高浓度时段,而在PM2.5双峰时段,它们的含量有所降低。     

Do lower electricity storage costs reduce greenhouse gas emissions?

In the electricity sector, innovation in large-scale storage is anticipated to reduce costs and improve performance. The effect on greenhouse gas emissions of lower storage costs depends on the interactions between storage and the entire grid. The literature has disagreed on the role of storage in reducing emissions. In this paper we present a stylized model, which suggests that the effect of storage costs on emissions depends on the supply responsiveness of both fossil and renewable generators. Under common conditions in the United States, lower storage costs are more likely to reduce emissions when wind investment responds to equilibrium electricity prices and when solar investment does not. Simulations of a computational model of grid investment and operation confirm these intuitions. Moreover, because of its effect on coal and natural gas–fired supply responsiveness, introducing a carbon dioxide emissions price may increase the likelihood that lower storage costs reduce emissions.     

臭氧氧化处理化工污水厂尾水

采用臭氧氧化工艺处理某化工污水厂尾水,考察了臭氧投加量对废水处理效果的影响,并进行了反应动力学研究。实验结果表明,最佳臭氧投加量为67 mg/L,在此条件下,处理后废水的COD去除率为19%,色度去除率为90%,UV254去除率为79%,BOD5/COD为0.11。反应动力学分析结果表明:臭氧氧化去除废水COD的反应适合采用二级反应动力学进行拟合,二级反应动力学方程为y=0.000 1x+0.000 3,相关系数为0.938 5;臭氧氧化去除废水色度的反应更适合采用一级反应动力学进行拟合,一级反应动力学方程为y=0.105 0x-0.018 4,相关系数为0.990 3。     

西部大开发政策效应评价

经过15年的西部大开发,西部各个省份的综合发展水平怎样?西部大开发是否显著缩小西部与东部地区在综合发展水平和经济增长的差异?哪些政策起到了关键作用?是本文将要探讨的问题。研究方法主要是通过模型与数据的实证研究方法对西部大开发的政策效应进行评价。内容包括:一是通过构建包含了社会、经济、科教与文化、对外开放和资源与环境五大类25个分项指标的综合发展水平评价体系,使用从1997到2013年31个省市的指标数据,并计算出综合评价值来考察西部大开发政策对西部地区各个省份整体发展的影响。从评价值排名上来看发现只有重庆、陕西、四川和内蒙古综合发展水平排名提升明显,而新疆、宁夏和青海发展差距还在拉大,其他省份排名变化不大。从分类指标来看,西部地区整体上社会发展和资源环境与生态提升较为明显,说明中央对于公共服务的转移支付和"退耕还林还草"等保护环境与生态的政策起到了一定的成效。二是选取了交通基础设施建设、中央转移支付和税收优惠这三个主要政策作为计量模型的政策变量,分别考察西部大开发整体和分项政策对于综合发展水平和经济增长率的影响。通过系统GMM方法估计整体西部大开发整体政策效应,以2000年前后对比,政策实施对GDP增长率的提升并不显著,综合发展水平也没有收敛。而以2008年为时间节点,综合发展水平和经济增长速度都得到了显著提升。通过DID估计分项政策,结果表明基础设施投入和转移支付能够有效提升综合发展水平和经济增长速度,税收优惠提升相对较弱。本文建议:在交通基础设施投入方面继续对西部地区予以倾斜,特别是建设西部地区通往东中部地区的交通大通道;培育和完善西部地区的市场经济体系,政府较少干预企业投资决策;加强对于西部落后地区、偏远地区的公共产品投入,加强扶贫工作。