基于环境外部经济性的环境治理手段——以滇池白鱼河河口湿地地块的模拟案例为例

为了解决湿地建设投资渠道的问题,提出了利用环境外部经济性来改善和保护环境的发展思路。其重点是将湿地从普通概念上的公共产品转化为一段时限内的经营性项目,利用某种经营项目所产生的对环境的外部经济性来改善环境。为了验证上述思路的可行性,结合滇池湿地现状,利用湿地的自然景观价值,通过企业对这种生态景观环境的资源化利用过程,即湿地景观建设和管养,增强对污染水体的治理等角度进行了实际模拟实验。     

郑州市某城区冬季不同污染水平大气VOCs特征及源解析

于2019年1月3～23日,在郑州市某城市站点对挥发性有机物(VOCs)进行观测,研究不同污染水平下VOCs组成、变化特征、来源及其对二次有机气溶胶(SOA)生成的影响.结果表明,观测期间含氧VOCs和烷烃为VOCs的主要组分,乙酸乙酯和丙酮为最丰富的物种.清洁天演变至重度污染过程中,VOCs体积分数增高约1倍,大部分物种体积分数随污染程度加重而增高.基于正交矩阵因子模型(PMF),观测期间VOCs主要来源于机动车排放、工业排放、燃烧源、溶剂使用和液化石油气(LPG)使用,且不同污染水平下来源贡献差异明显,重污染期间工业排放和溶剂使用的源贡献分别增高至约清洁天的9倍和3倍.芳香烃为SOA生成潜势(SOA_p)贡献最大的组分,甲苯和间/对-二甲苯为贡献最大的物种,溶剂使用源为贡献最大的来源,重度污染期间总SOA_p增大至约清洁天的2.6倍.加强管控芳香烃类化合物及溶剂使用等相关源的排放对改善郑州市冬季霾污染具有重要意义.     

Determining Decision Thresholds and Evaluating Indicators when Conservation Status is Measured as a Continuum

Categorization of the status of populations, species, and ecosystems underpins most conservation activities. Status is often based on how a system's current indicator value (e.g., change in abundance) relates to some threshold of conservation concern. Receiver operating characteristic (ROC) curves can be used to quantify the statistical reliability of indicators of conservation status and evaluate trade‐offs between correct (true positive) and incorrect (false positive) classifications across a range of decision thresholds. However, ROC curves assume a discrete, binary relationship between an indicator and the conservation status it is meant to track, which is a simplification of the more realistic continuum of conservation status, and may limit the applicability of ROC curves in conservation science. We describe a modified ROC curve that treats conservation status as a continuum rather than a discrete state. We explored the influence of this continuum and typical sources of variation in abundance that can lead to classification errors (i.e., random variation and measurement error) on the true and false positive rates corresponding to varying decision thresholds and the reliability of change in abundance as an indicator of conservation status, respectively. We applied our modified ROC approach to an indicator of endangerment in Pacific salmon (Oncorhynchus nerka) (i.e., percent decline in geometric mean abundance) and an indicator of marine ecosystem structure and function (i.e., detritivore biomass). Failure to treat conservation status as a continuum when choosing thresholds for indicators resulted in the misidentification of trade‐offs between true and false positive rates and the overestimation of an indicator's reliability. We argue for treating conservation status as a continuum when ROC curves are used to evaluate decision thresholds in indicators for the assessment of conservation status. Determinación de Umbrales de Decisiones y Evaluación delos Indicadores cuando se Mide el Estado de de Conservación como un Continuo     

Supporting conservationists’ mental health through better working conditions

Biodiversity conservation work can be challenging but rewarding, and both aspects have potential consequences for conservationists’ mental health. Yet, little is known about patterns of mental health among conservationists and its associated workplace protective and risk factors. A better understanding might help improve working conditions, supporting conservationists’ job satisfaction, productivity, and engagement, while reducing costs from staff turnover, absenteeism, and presenteeism. We surveyed 2311 conservation professionals working in 122 countries through an internet survey shared via mailing lists, social media, and other channels. We asked them about experiences of psychological distress, working conditions, and personal characteristics. Over half were from and worked in Europe and North America, and most had a university-level education, were in desk-based academic and practitioner roles, and responded in English. Heavy workload, job demands, and organizational instability were linked to higher distress, but job stability and satisfaction with one's contributions to conservation were associated with lower distress. Respondents with low dispositional and conservation-specific optimism, poor physical health, and limited social support, women, and early-career professionals were most at risk of distress in our sample. Our results flag important risk factors that employers could consider, although further research is needed among groups underrepresented in our sample. Drawing on evidence-based occupational health interventions, we suggest measures that could promote better working conditions and thus may improve conservationists’ mental health and abilities to protect nature.     

基于正压密封方法的闭式采空区灭火技术

为提高闭式采空区密闭漏风控制效果,基于矿井空气流动基础理论,运用RFPA软件建立了注氮气室正压密封采空区数值模型,模拟分析了注氮气室正压作用对采空区密闭漏风行为的影响规律,提出了基于注氮气室正压密封方法的采空区灭火技术,并在恒大煤矿5333工作面采空区进行了应用.结果表明,在气室内氮气相对正压作用下,通风巷道向采空区漏风速度快速减小至0,并最终产生反向,形成由气室向外部微量漏氮气的状态,5333采空区采取正压密封方法后,内部CO、C2H4和温度快速消失和降低至安全范围值.     

阳极溶出伏安法连续测定底泥中的总镉和总铅

样品经盐酸-硝酸-氢氟酸-高氯酸消解后，用1＋1盐酸溶解残渣，以高氯酸做支持电解质，采用阳极溶出伏安法的标准加入法，测定样品中的总镉和总铅，取得满意结果。     

水权交易第三方效应辨识研究

水权交易是提高水资源配置效率和利用效率的有效途径,且在不少缺水地区开始实施并日渐活跃.但交易过程中常常会优先考虑交易主体的利益,而交易所影响到的第三方由于没有契约保护,常常未能进入水权交易的博弈过程,第三方效应的存在是对水权市场效率和公平的严峻挑战.本文在研读大量国内外文献研究的基础上,辨识水权交易对不同的客体所产生的生态正效应、当地经济正效应、技术进步正效应三种正效应和水资源供给可靠性负效应、农村经济负效应、回流水量负效应、水质负效应、水源地负效应等七种第三方负效应.通过对这些正、负效应的辨识,揭示水权交易第三方效应的丰富外延,也有助于认识和解决水权交易中的效率和公平问题.     

企业积极环境行为的层次及其政策设计

企业积极的环境行为是我国建设生态文明社会的重要着力点,使企业成为积极的环境行为主体是环境政策的重要目标.由于企业在环境治理中存在达到企业最优污染控制水平、社会最优污染控制水平及污染完全控制三个目标层次的选择,企业在不同的污染控制目标层次上,其行为是有差异的.本文针对企业不同的污染控制目标层次,提出企业积极环境行为存在循环经济、利益调配、非此即彼三个行为层次的选择.每一个行为层次和相关的目标层次相对应.不同层次的环境行为,其行为动力和政策要求是有差别的.本文指出,从循环经济层次到利益调配层次、再到非此即彼层次,企业积极环境行为的动力是逐步递减的,并针对这一特征分别设计了相关的环境经济政策,以促进企业积极的环境行为.     

基于多种新型受体模型的PM2.5来源解析对比

为了解多种新型受体模型的适用性,利用正定矩阵分解/多元线性引擎2-物种比值（PMF/ME2-SR）、偏目标转换-正定矩阵分解（PTT-PMF）、正定矩阵分解（PMF）和化学质量平衡（CMB）这4种受体模型对我国北方典型城市细颗粒物(PM_2.5)数据进行同步解析并互相验证.结果发现,燃煤源（25%～26%）、扬尘源（19%～21%）、二次硝酸盐（17%～19%）、二次硫酸盐（16%）、机动车源（13%～15%）、生物质燃烧源（4%～7%）和钢铁源（1%～2%）这7种主要污染源对研究地区PM_2.5有贡献.通过比较不同模型获得的源成分谱和源贡献以及计算各源的差异系数（CD）和平均绝对误差（AAE）,发现4种模型的解析结果具有较高的一致性（平均CD值在0.6～0.7之间）,但不同模型对各污染源中组分的识别存在差异.相比于传统PMF模型,PMF/ME2-SR模型由于纳入一次源类的特征比值,能够更好地区分源谱特征较为相似的源类,如扬尘源的CD和AAE分别比PMF模型低15%和54%; PTT-PMF模型以实测一次源谱和虚拟二次源谱为约束目标,计算的二次硫...     

广播媒介在灾害救助中的积极作用——基于汶川等十县市的调查结果

灾害事件发生后,信息的有效传播对于灾害救助意义重大.灾害事件往往伴随电力、交通、通讯的中断,导致许多传播媒介无法发挥作用,而广播媒介因其较强的抗灾害能力在灾害信息传播过程中保持了相对畅通,成为灾害救助的重要媒介.本文介绍了广播媒介在自我救助、专业救助和社会救助中的不同作用,进一步探讨了几种常见的传播媒介的抗灾害能力,并针对广播媒介在灾害救助中存在的问题提出了一些建议.