氯代烃在铜电极上的电还原特性和pH值的影响

采用循环伏安法,对氯代烃类化合物在铜电极表面上的电还原特性进行了研究,结果表明,氯代烷烃类化合物能在铜电极表面被直接还原,氯代芳烃不易在铜电极上被直接还原．碱性条件有利于中间体碳负离子的形成;在酸性条件下,碳负离子与氢离子之间反应的几率增大,导致通过溶液的电流值增加．pH值对不同氯代烃在铜电极上的电还原特性有不同程度的影响,这主要取决于碳链(或苯环)上其它取代基的性质、结构、数量和它与氯在苯环上的相对位置．     

长沙市夏季大气臭氧生成对前体物的敏感性分析

本文利用长沙市区环境空气质量监测站点在线观测资料,结合罐采样-三级冷阱预浓缩-气相色谱法分析非甲烷烃类化合物和衍生化-高效液相色谱法分析醛酮类化合物,基于观测的光化学模型分析了长沙市区2017年5月和9月部分时段臭氧生成对前体物的敏感性.结果表明,观测期间长沙市区臭氧浓度日变化均呈现典型的单峰特征,峰值浓度出现在15时左右,凌晨高浓度一氧化氮呈现对臭氧明显的滴定效应;5月非甲烷烃浓度和醛酮总浓度较9月高,非甲烷烃主要组成为烷烃和芳香烃类,其次为植物源烃类,而甲醛、乙醛和丙酮为醛酮类化合物主要组分.白天随着光化学过程的发展,非甲烷烃被逐渐消耗,其活性浓度随之降低.模型分析发现:5月份氮氧化物和植物源烃类对长沙市区臭氧生成贡献最大,削减氮氧化物对臭氧控制最为有效;而9月臭氧生成对烯烃和芳香烃最为敏感,削减人为源烯烃和芳香烃对臭氧控制最为有效.     

短链氯化石蜡及其环境污染现状与毒性效应研究

短链氯化石蜡是碳链长度为10至13个碳原子的正构烷烃经氯化衍生而成的复杂混合物.作为《关于持久性有机污染物的斯德哥尔摩公约》增列持久性有机污染物(persistent organic pollutants,POPs)中的一类化合物,2008年10月在瑞士日内瓦召开的联合国环境规划署POPs审查委员会的第     

浙江三门湾柱样沉积中长链烯酮、正构烷烃和多环芳烃组成、分布特征及对厄尔尼诺／拉尼娜事件的追踪

利用气相色谱对浙江三门湾H30柱样沉积中长链烯酮、正构烷烃和多环芳烃组成和来源进行分析,并对柱样沉积中相关有机地化指标与厄尔尼诺／拉尼娜事件的关联性进行了探讨。正构烷烃GC谱图显示碳数分布范围为C14-C35,呈双峰型,低碳峰群的主峰为C17-C19,高碳峰群的主峰为C27-C31,这种分布特征表明三门湾沉积物中陆地高等植物和海洋菌藻类的烷烃共存。根据多环芳烃的菲／蒽比值、荧蒽／芘比值、2-3环化合物总量和4环以上化合物总量等可推断,三门湾沉积地层中的多环芳烃主要来源于化石燃料的不完全燃烧物和石油源（航运事件）。基于精确的。mPb定年,1822-2005年间正构烷烃和多环芳烃含量分布、分子组合特征指数可能与厄尔尼诺,拉尼娜事件具有一定的关联。具体表现在,长链正构烷烃的含量与总多环芳烃含量变化具有良好的一致性,二者含量和花、CPI、烷烃C旷C19在厄尔尼诺年增加（尤其在厄尔尼诺结束年）,指示陆源有机质输入和海洋菌藻类一致增加;而二者含量和∑C21／∑C22＋、烷烃C15．C19在拉尼娜事件时降低,表明海洋菌藻类减少。     

神经网络法预测分子总表面积的研究

本文用误差反向传播人工神经网络（ＡＮＮ）预测有机分子的总表面积，提出一组分子描述码（描述分子的分支性、不饱和性和成环性）作为输入的特征参数，预测结果：对于烷烃、烯烃、炔烃、脂环烃、芳烃、卤代烃、醇、醛、酮、酸、酯、胺、硫醇、杂环等１４类有机物平均误差为２．５８％，对于多环芬烃平均误差为２．８８％。根据ＡＮＮ法提供的信息，用统计分析的方法，得到分子总表面积与分子描述码之间的关联式，用它估算分子总表面     

正构烷烃示源的阜新细河河道石油烃类污染特征及其影响因素分析

研究典型北方城市阜新主河(细河)河底沉积物和水中正构烷烃的含量和组成特征及相关关系,并对北方城市河道系统石油烃类污染的来源示踪和环境影响效应进行分析。选取细河阜新段分布的12个河底沉积物样点和13个水体样点环境样品的正构烷烃浓度、组成特征和物源指示性指标(主峰碳数、碳优势指数I_CP、短链/长链正构烷烃丰度比值R_L/H等)进行石油烃类污染物的示源分析,采用模型构建的方法进行了水体和沉积物正构烷烃浓度和I_CP转换关系的建立,并讨论了二者结果对应性差异产生的主要原因。结果表明,(1)正构烷烃特征分布显示,细河河道正构烷烃组成主要分为两种类型：单峰型和双峰型,以双峰型为主。低碳数主要以n C₁₅、n C₁₇、n C₁₉为主碳峰或次主峰,高碳数主要以n C₂₉、n C₃₁为主碳峰或次主峰。(2)沉积物和水体I_CP和R_L/H分析显示,细河阜新段河流中正构烷烃主要来源于石油和不完全燃...     

低碳脂肪族含氧化合物的气相色谱分析和环境样品的分析实例

用 Chromosorb101固定相对低碳脂肪族含氧化合物醇、醛、酮、酸和酯五大类做了气相色谱分析,并对含有该族化合物和低碳烷烃混合物的环境样品——石腊氧化尾气做了定性和定量分析,得到25—27个峰.     

不同底物和环境条件对两株铜绿假单胞菌接触烷烃方式及降解活性的影响

考察了不同烷烃底物和温度、酸度、盐度等环境条件对两株铜绿假单胞菌接触烷烃方式和降解活性的影响.结果表明,微生物接触烷烃的两种方式——直接接触方式和乳化接触方式同时存在于菌体降解烷烃过程中且受底物和环境条件的影响.底物烷烃碳数的增加对菌株两种接触方式降解烷烃都有利,而盐度增加对它们都不利;高温、偏碱性环境以及延长降解时间有利于菌体以乳化方式降解烷烃;低温、中性溶液环境有利于菌体以直接接触方式降解烷烃.     

环境空气中短链氯化石蜡研究进展

短链氯化石蜡(SCCPs)是碳链长度为10至13个碳原子的正构烷烃氯代衍生物。SCCPs具有持久性、生物累积性、长距离迁移能力、以及毒性作用。SCCPs已被《关于持久性有机污染物的斯德哥尔摩公约》增列为持久性有机污染物审查范围内,引起了全球关注。SCCPs在环境各介质及生物体内均有检出,近年来,在室内空气和灰尘中也检出了大量SCCPs,其已成为人体暴露的一个重要来源。本文就大气环境及室内空气与灰尘中氯化石蜡(CPs)的采样与分析方法、污染水平与来源,及人体暴露概况进行了综合阐释,以期为我国大气和室内环境中CPs的研究工作提供参考。     

石油污染土壤的微生物修复及土壤微生物活性变化

为快速有效地测定石油污染土壤中功能性微生物的活性变化,分别以石油烃、正十六烷烃、多环芳烃为自定义碳源,应用Biolog法研究油污土壤生物修复过程中石油烃、烷烃、多环芳烃降解菌的代谢活性.结果显示,向油污土壤中投加混合降解菌群进行生物强化修复处理,可以有效去除土壤中的石油烃,修复13周土壤中石油烃去除率达到42.3%;生物刺激和自然修复对土壤石油烃的去除率分别为28.3%和20.5%.Biolog测定结果表明,生物强化法修复初期的土壤微生物群落对石油烃、烷烃两种碳源的代谢能力较强,而生物刺激法修复后期的土壤微生物群落对烷烃有较强的代谢能力;不同处理的土壤微生物群落比较偏好、利用率较高的碳源是石油烃,其次是烷烃,而对多环芳烃几乎不利用;土壤中石油烃、烷烃降解菌的活性越大,土壤微生物对石油烃的去除效率越高.上述研究结果说明,通过利用Biolog法测定土壤微生物活性变化可有效指示土壤中石油烃的去除效果.     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

Representation of the world's biophysical conditions by the global protected area network

Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.     

Quantitative composition of the defensive secretion ofBledius species (Coleoptera: Staphylinidae: Oxytelinae) is adapted to naturally occurring predators

Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.     

Democracy versus development: New urban debates

The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

A framework to measure the wildness of managed large vertebrate populations

As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.     

Sexual Predators,Energy Development,and Conservation in Greater Yellowstone

Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.     

Comparison of the insecticidal effects of water extracted and intact aromatic plants onAcanthoscelides obtectus,a bruchid beetle pest of kidney beans

Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.