观测数据权重对地下水有机污染物生物降解模型参数估计的影响

地下水多组分反应运移模型是刻画解释微生物降解地下水有机污染物的水文地质、生物地球化学耦合过程并对各组分分布特征进行预测的重要工具.反应运移模型往往包含多个参数,并含有多种不同生物化学组分的观测数据,高维参数和观测数据类型的多样性给模型参数的反演带来了极大的困难.因此,本文以反应运移软件PHT3D模拟某污染场地地下水中有机污染物生物降解的理想正问题为例,对比讨论了不同观测数据权重对反应运移模型参数估计的影响.结果表明:未考虑观测数据权重时参数估计结果与真实值相差较大,而采用反映观测误差的权重时参数估计值与真实值更接近.敏感性分析表明,参数对于不同观测组数据的敏感度有明显差异.对于本例,生物降解模型中的降解反应参数最敏感,其次是溶解速率迁移常数,多相溶解度摩尔分数敏感度较小.     

Biodiversity of the ground-dwelling spider fauna of afforestation habitats

The aim of this study was to assess spider diversity among habitats that are typically used for afforestation in Ireland, and to identify habitat parameters which could potentially be used as indicators of their biodiversity value. Ground-dwelling spiders were surveyed in 24 sites across Ireland, with eight sites of each of the following habitat types: improved grassland, wet grassland and peatland. The spiders were sampled using pitfall traps which were located within the major vegetation types present in each site as well as within supplementary habitat features which may add to biodiversity value of the whole site such as hedgerows, flushes and the edges of ditches and streams.Each habitat supported distinct spider assemblages that reflect major differences in both environmental conditions and management regime. The improved grasslands had low spider species richness and low variation in assemblage structure which is probably related to the intensive management of this habitat. In this case hedgerows maybe an important aspect of the spider diversity within agricultural landscapes. The peatlands, and to a lesser extent wet grasslands, supported a diverse and specialist spider fauna, including a number of rare species; this may be due to differences in soil moisture and plant architecture. Indicators of biodiversity value identified included wet flushes in the peatlands and low grazing pressure in the wet grasslands. This study suggests that in terms of biodiversity value improved grassland is the preferable habitat for afforestation, because of the poor baseline spider diversity. However, it may be unrealistic to expect land owners to afforest their most productive agricultural land, so the management and habitat indicators identified in this study may be of use for assessing habitat quality among the wet grassland and peatlands to allow sites with lower biodiversity value to be identified.     

模拟涨潮的复杂海岸类型岸线自动提取方法

传统的海岸线提取方法往往仅针对某种类型的海岸有效,对于多种类型混合海岸区域,则需要对图像分类裁剪、分别提取岸线、拼接图像才能提取出完整的海岸线,该过程不仅实现较为复杂,而且将不同类型海岸严格划分开的难度也很大,因此,本文提出了一种适用于混合海岸类型区域提取海岸线新方法——模拟海水涨潮过程的海岸线自动提取方法。首先采用波段差决策树分类分析方法（spectral difference decision tree,SDDT）对遥感影像进行分类,根据地物类型差异将各区域类别标记为"可涨潮区域"与"不可涨潮区域"两类;其次,通过计算每个斑块区域的面积,将面积小于某一预设阈值的区域块定义为噪声区域,去除所有噪声区域;然后,再通过最大矩形填充算法（maximum rectangle filling algorithm,MRFA）模拟海水涨潮逐步填充"可涨潮区域"并提取海岸线。本文方法提取的海岸线较为连续,不受地物分类结果图中的少量误分类斑块的影响。     

CL-20/HTPB热分解机理的ReaxFF/lg反应分子动力学模拟

目的 揭示CL-20和HTPB复合体系的热分解机理,同时为CL-20/HTPB复合推进剂配方设计与应用提供理论依据。方法 采用反应分子动力学方法(ReaxFF/lg),研究CL-20/HTPB混合体系在2 500~3 500 K中5个温度下的热分解机理。结果 混合体系中的CL-20分子间反应路径仍为脱硝基和开环等反应。HTPB为混合体系引入大量的H原子与OH基团,这些自由基会与CL-20及CL-20的分解产物发生反应,例如与HNO2的大量化学反应促进了CL-20的热分解。相比CL-20单质体系,混合体系下,HNO2生成反应数量均有不同程度的增加。通过与单组分产物数量的比较可以发现,H2O的含量大大增加,且曲线到达峰值的时间更短,体系分解反应速率更快,同时CO2的含量也大幅度地减少。除此之外,所计算的混合体系的活化能(Ea)与指前因子的自然对数lnA分别为114.684 kJ/mol与25.896。对比CL-20单质体系,混合体系的活化能较小。结论 HTPB会对CL-20的热分解起到促进的作用,降低了系统对热刺激的不敏感程度。     

沼气产生的两步一级反应耦合模型

根据有机物厌氧产生沼气的生化机理,假设沼气通过两步相互衔接的一级反应生成,即复杂有机物的水解酸化反应和简单有机酸的产气反应.根据假设,建立了基于两步一级反应耦合的沼气产气率与产气量随时间变化的数学模型.该模型用统一的数学公式对沼气产气率随时间变化的倒“U”形曲线进行了解释,指出这一过程是两步相互衔接的一级反应相互作用的结果.已知有机物质量,通过拟合或根据经验得出K值后,利用该模型可解出任一时刻有机物的产气率、产气量、最大产气率及其发生的时间.拟合表明,两步反应的反应常数趋于相等.利用该模型可导出已有的Scholl Canyon模型,并可对Palos Verdes模型和Sheldon Arleta模型的经验假设进行解释.      

Cluster analysis: A technique for estimating the synoptic meteorological controls on air and precipitation chemistry—Method and applications

Combining the pattern recognition capabilities of cluster analysis with isobaric air trajectory data is a useful way of quantifying the influence of synoptic meteorology on the pollution climatology at a site. A non-hierarchial clustering of 1000 mb isobaric trajectories, using squared Euclidean distance as a similarity measure, leads to the identification of a finite number of distinct synoptic patterns. Typical airbore and aqueous pollutant concentrations associated with each of these patterns may then be established. By considering 3-day air trajectories in this study, the “history” of an air parcel is captured in an improved manner, when compared with attempts to use individual day weather “types” to characterize meterological situations.     

Spillover of functionally important organisms between managed and natural habitats

Land-use intensification has led to a landscape mosaic that juxtaposes human-managed and natural areas. In such human-dominated and heterogeneous landscapes, spillover across habitat types, especially in systems that differ in resource availability, may be an important ecological process structuring communities. While there is much evidence for spillover from natural habitats to managed areas, little attention has been given to flow in the opposite direction. This paper synthesizes studies published to date from five functionally important trophic groups, herbivores, pathogens, pollinators, predators, and seed dispersers, and discusses evidence for spillover from managed to natural systems in all five groups. For each of the five focal groups, studies in the natural to managed direction are common, often with multiple review articles on each subject which document dozens of examples. In contrast, the number of studies which examine movement in the managed to natural direction is generally less than five studies per trophic group. These findings suggest that spillover in the managed to natural direction has been largely underestimated. As habitat modification continues, resulting in increasingly fragmented landscapes, the likelihood and size of any spillover effect will only increase.     

Women's experiences with second trimester prenatal diagnosis

By means of questionnaires, 100 women were asked for their experiences concerning prenatal diagnosis. At four standardized stages of the pregnancy a questionnaire was filled in asking for: expectation, knowledge, attitude towards termination of the pregnancy in case of abnormal findings, reactions to the counselling and the obstetric treatment, interpretation of own risk, experiences since the normal test results were known and ideas to improve the treatment. With regard to the effect of pre-amniocentesis counselling it is concluded that the counselling had little impact on decision making; the counselling caused an increase of factual knowledge: somewhat more than half of the women who did not give a correct answer before counselling, indicated the right answer some time afterwards. Presumed differences in reaction patterns for a number of characteristics were not affirmed by the study; the reactions during the procedure of prenatal diagnosis seem to be highly individual and difficult to predict. In addition to the reactions of the 100 women described in this study, the responses to the first questionnaire of another 16 patients, declining amniocentesis after counselling, are presented.     

<Emphasis Type="Italic">Tenebrio</Emphasis> beetles use magnetic inclination compass

Animals that guide directions of their locomotion or their migration routes by the lines of the geomagnetic field use either polarity or inclination compasses to determine the field polarity (the north or south direction). Distinguishing the two compass types is a guideline for estimation of the molecular principle of reception and has been achieved for a number of animal groups, with the exception of insects. A standard diagnostic method to distinguish a compass type is based on reversing the vertical component of the geomagnetic field, which leads to the opposite reactions of animals with two different compass types. In the present study, adults of the mealworm beetle Tenebrio molitor were tested by means of a two-step laboratory test of magnetoreception. Beetles that were initially trained to memorize the magnetic position of the light source preferred, during the subsequent test, this same direction, pursuant geomagnetic cues only. In the following step, the vertical component was reversed between the training and the test. The beetles significantly turned their preferred direction by 180 degrees. Our results brought until then unknown original findings that insects, represented here by the T. molitor species, use-in contrast to another previously researched Arthropod, spiny lobster-the inclination compass.     

北京市三类住宅室内CO、颗粒物污染及其元素分析

根据对三类有代表性住宅进行一年四季的有关监测及对户主所作个体碳氧血红蛋白(COHb)测定,研究表明室内空气污染较严重,尤其在冬季,颗粒物浓度普遍经常超标,CO更甚,可高达47ppm,室内空气污染与住房类型,特别是与取暖方式,关系密切,同类住宅当改用了中心供暖后,污染大为改善,30种元素分析表明是典型的燃煤夹杂风砂的污染,室内Pb浓度较高可能与使用液化石油气(LPG)灶具有关,吸烟的影响有时可被严重的室内污染所掩盖。     

四川盆地卤水的氢、氧同位素地球化学特征及其成因分类研究

四川盆地地下卤水分布广泛，类型繁多，依据氢、氧同位素地质学方法及其分布规律性，将盆地卤水明确划分出大气水淋滤型、海相沉积型、海相沉积-大气降水叠加型和海相沉积-岩浆水叠加型等四种成因类型。该分类明确，标志明显，有确定的成因涵义，取得了较好的效果。     

几种湿式烟气脱硫吸收反应的热力学分析

计算了３种湿式烟气脱硫吸收反应达到平衡态时ＳＯ２的分压力。计算结果显示：对于３种湿式脱硫反应，平衡态ＳＯ２的分压力都随温度的升高而增大。所以从化学热力学角度看反应温度高不利于脱硫。综合考虑脱硫效率、运行费用、是否堵塞等因素，推荐采用双碱法进行烟气脱硫。     

生态系统服务时空演化的非线性影响因子——以钱塘江流域为例

为深入探究不同尺度、不同类别影响因素对不同类型生态系统服务的影响程度和复杂关系,本文测定了钱塘江流域7项生态系统服务的时空变化,并通过随机森林模型识别了各单项生态系统服务不同尺度自然环境因素和社会经济因素的影响程度和相对重要性,并评估了主导影响因素的边际效应.结果表明：2010~2017年,各单项生态系统服务在时空变化上具有明显的空间分异特征;不同类型生态系统服务受不同尺度自然环境因素和社会经济因素的共同影响,但其影响程度存在明显差异,格网尺度、自然环境因素的影响相对较大,建设用地、耕地及与其直接相关的社会经济因素的变化改变和塑造着生态系统服务的演化过程;主导影响因素与各单项生态系统服务之间存在复杂的非线性关系,各影响因素指标的变化对各年份生态系统服务具有非平稳的影响,如建设用地增加初期对多项生态系统服务的影响更为复杂和剧烈.     

环境规制对碳排放时空格局演变的作用路径研究——基于东北三省地级市实证分析

基于2005-2016年东北三省36个地级市面板数据,定性分析环境规制与碳排放的时空格局演变特征,并利用中介效应分析法定量研究环境规制对碳排放的影响及作用路径。结果表明：（1）从各城市对比来看,环境规制强度呈现出明显的市域差异,碳排放量呈先增加后减小态势。（2）从空间格局来看,环境规制强度呈现由北向南逐渐增强的态势,区域间差异逐渐增大。环境规制的高水平类型分布集中,城市数量最多;低水平类型均位于黑龙江省北部,城市数量最少。碳排放量的高水平类型集中分布在辽东半岛以及大庆市和吉林市等石油型、冶金型城市,低水平类型城市数量呈波动增加,主要分布在东北北部,且向南逐渐扩散。（3）东北三省严格的环境规制不仅直接抑制碳排放,也可以通过优化产业结构和精简粗放投资间接抑制碳排放,地方政府竞争则会减弱环境规制对碳排放的抑制效应。     

A holistic approach for evaluating ecological water allocation in the Yellow River Basin of China

The characteristics and sustainable management of water resources on a basin scale require that they should be managed using a holistic approach. In this study, a holistic methodology called the holistic approach in a basin scale (HABS) is proposed to determine the ecological water requirements of a whole basin. There are three principles in HABS. First, ecological water requirements in a basin scale indicate not only the coupling of hydrological and ecological systems, but also the exchange of matter and energy between each ecological type through all kinds of physical geography processes. Second, ecological water requirements can be divided into different types according to their functions, and water requirements of different types are compatible. Third, ecological water requirements are related to a multiple system including water quality, water quantity, and time and space, which interact with each other. The holistic approach in a basin scale was then used in the Yellow River Basin and it suggested that 265.0 × 10⁸ m³ of water, 45% of the total surface water resources, should be allocated to ecological systems, such as rivers, lakes, wetlands and cities, to sustain its function and health. The ecological water requirements of inside river systems and outside river systems were respectively 261.0 × 10⁸ and 3.65 × 10⁸ m³.     

湿法烟道气脱硫脱硝反应动力学

近年来,发展的同时脱硫脱硝方法,是借助于氧化不容易溶解的NO到容易溶解的NO_2,或者利用水溶性亚铁螯合物作为一种催化剂加速NO的吸收,也就是亚铁螯合物能够与NO形成一个络合物而促进NO的吸收。或者应用水溶液中NO_x被溶解的SO_2还原形成N_2,N_2O或还原到氮化物如NOH(SO_3~(2-)_2、 NH_2SO_3~-和NH_4~+而除去,而SO_2被氧化生成硫酸盐。本文综述了湿法烟道气脱硫脱硝反应动力学和机理以及一些中间化合物形成与消失的过程。     

Aggregation and analysis of volatile organic compound emissions for regional modeling

A general two-step procedure for aggregating the hundreds of reported volatile organic compounds (VOCs) into a much smaller set of lumped classes appropriate for regional airshed modeling is described. In the first step, the compounds are condensed into a manageable number of emission categories which could be adapted to a variety of molecularly-based lumped chemical mechanisms. In the second step, the emissions are further aggregated into a smaller set of VOC classes which directly correspond to those in a particular model's mechanism. The application of this procedure is illustrated by aggregating the National Acid Precipitation Assessment Program (NAPAP) anthropogenic VOC emissions inventory the U.S. first into the 32-class system, and then into the groups of model species used in the latest version of the Regional Acid Deposition Model (RADM2.0). The importance of different VOC categories and source types on regional pollution production is explored by comparing the contributions of each of the emissions groupings, RADM model species, and major emissions sources, to total moles carbon VOC reacted in model simulations. For this particular anthropogenic inventory and chemical mechanism, it is found that over 50% of the moles carbon reacted is associated with mobile sources. Such analysis can help indicate which uncertainties in anthropogenic emissions inventories may have the greatest impact on results of regional simulations.     

Eco-efficient producer services—what are they, how do they benefit customers and the environment and how likely are they to develop and be extensively utilised?

The potential environmental benefits of moving from a product-based economy to a functional economy involving greater use of services is a subject of increasing interest and debate in the field of eco-efficiency. This paper provides a typology and fuller analysis of eco-efficient producer services than hitherto reported. Three broad classes of service are described and assessed: product based including product results, product utility and product extension; electronic substitution and information based. Examples of each are drawn from a major study on the successes and barriers of eco-services in Europe. The paper concludes that while there are a number of areas of success, there are considerable barriers to wider development and uptake of such services, and that many of the more successful service applications are not necessarily driven by environmental considerations. The paper warns that the shift from products to services cannot be assumed to be eco-efficient and there are a number of rebound effects which need to be carefully analysed.     

不同布局高层建筑群的风环境状况评价

采用数值模拟方法对由6幢方形截面高层建筑组成的建筑群的周围风环境进行了计算和分析。6幢建筑起初呈两行三列布置,通过改变各列建筑的横向间距,得到了6种不同布局型式的建筑群。对各建筑群周围人行高度处的风速比和风速矢量场进行了计算和分析、比较,据此对不同布局形式的建筑群的风环境状况作了评价,提出了通过调整平面布局改善高层建筑群风环境的措施和建议。