内蒙古额济纳旗西部ZK0-1井二叠系烃源岩特征及其意义

银额盆地以古生界为目的层的钻井极少,获得的钻井岩心更是十分有限。对银额盆地西部路北凸起带ZK0-1井揭示的地层岩性组合特征进行分析,在此基础上对下二叠统暗色泥岩层段岩心系统地采集烃源岩样品,并进行有机质丰度、干酪根类型、有机质成熟度等地球化学特征分析。结果表明,银额盆地路北凸起带二叠系烃源岩厚度大(单层厚度大于43m),有机质丰度高(平均有机碳含量为3.1%),为以Ⅱ型干酪根为主、低成熟—成熟演化阶段的良好烃源岩。通过与二叠系地表剖面烃源岩地球化学特征对比,探讨了风化作用对烃源岩评价指标的影响。     

青岛市秋冬季霾期PM1及其含碳组分理化特征及来源研究

对2017年11月1日—2018年1月31日与2018年11月1日—2019年1月31日连续两年青岛市大气PM₁进行监测,获取了PM₁中含碳组分的变化趋势,结合国控站点监测数据和气象条件,分析了秋冬季PM₁来源.结果表明：2017、2018年秋冬季观测期间PM₁日均质量浓度分别为40.58±25.98、42.55±25.05 μg/m³;霾日质量浓度分别为84.71±16.70、81.52±18.39 μg/m³.与2017年相比,2018年同期PM₁质量浓度增长4.85%,霾日下降3.76%.2017年霾日PM₁中OC、EC质量浓度分别为13.67±3.95、3.95±1.02 μg/m³,2018年分别为16.48±6.34、3.34±1.16 μg/m³.与2017年相比,2018年霾日OC质量浓度增长20.56%,EC下降15.44%.2017、2018年霾日SOC质量浓度分别是非霾日的1.28和2.15倍,表明霾污染发生时易发生有机碳二次转化.含碳组分主成分分析均解析出3个因子.因子1解释变量均最大,分别为58.98%、67.14%,其表征含碳组分主要源于生物质燃烧、燃煤、道路扬尘及汽油车尾气等排放源.由后向气流轨迹分析得出,2017、2018年秋冬季气团轨迹多起源于内蒙古,经河北、天津、山东等省市抵达青岛.     

PLAM指数跟踪方法对中国沙尘天气过程及其波动变化特征的研究

采用1980-2011年气象台站地面气象要素观测资料、高空探空资料,时间和空间加密气象观测站资料,以及中国气象档案馆原始天气图表等资料,基于沙尘气溶胶浓度（PM₁₀）潜势源地贡献函数PSCF（Potential source contribution function）的沙尘系统追踪方法,发展空气质量气象条件PLAM（……）指数对沙尘天气过程的路径跟踪,给出1980-2011年东北亚沙尘天气过程特征分布;采用Spline趋势分析,讨论沙尘天气系统强度的年变化特征。结果表明：基于气溶胶浓度PSCF函数和气象条件PLAM指数追踪得出,中国和东亚地区沙尘天气过程年际强度变化并非单调减弱,具有历史持续性与转折突变性并存的波状变化趋势,出现准10 a的高低频活动特征。     

青藏高原5月大气热源与黑龙江省盛夏降水的关系

利用1961—2017年黑龙江省夏季降水资料和NCEP再分析资料,采用奇异值分解、相关分析、回归分析等方法,研究了青藏高原大气热源与黑龙江省盛夏降水的关系及可能的影响机制。结果表明:5月青藏高原热源与黑龙江省7月降水关系最密切,当5月高原东部热源偏强时,7月黑龙江省中部降水显著偏少。5月热源偏强年,在副热带西风急流的作用下,7月中纬度环流呈现类似“丝绸之路”型遥相关波列,同时东亚沿岸环流呈现类似“东亚—太平洋”型遥相关波列,在二者共同作用下黑龙江省受反气旋式环流影响,7月降水偏少。     

2006年以来《气象与减灾研究》期刊评价指标分析

对2006年以来《气象与减灾研究》的多项期刊评价指标进行统计分析,并对期刊稿源及网站建设情况进行细致调查。结果表明：1） 自2006年更名以来,期刊发展较快,然而期刊的进一步发展已经遇到“瓶颈”,即缺乏长期稳定的优质稿源;2） 拓宽优质稿源是期刊进一步发展的首要任务;3） 编辑部须重视期刊网站的建设、维护及更新,为读者、作者提供优质服务,以利期刊更好发展。     

青藏高原东北部地区闪电特征初步分析

利用VHF辐射源三维定位系统及快、慢天线资料,对青海大通地区5次雷暴过程中云闪、负地闪、正地闪的起始高度、持续时间、辐射源数目及正、负地闪云内放电过程的持续时间和回击次数进行了统计分析.研究表明,该地区闪电持续时间较短,平均＜0.5 s;正、负地闪首次回击发生前均有较长时问的云内放电过程,正地闪的云内放电过程持续时间略长于负地闪;负地闪的回击次数较少,平均为2.5次,其中40％的负地闪只有1次回击,而正地闪回击次数均为1次;云闪的起始高度最高,负地闪的起始高度低于云闪,正地闪的起始高度最低;云闪产生的辐射源数目最多,负地闪少于云闪,正地闪产生的辐射源数目最少.     

The influence of freezing drizzle on wire icing during freezing fog events

Both direct and indirect effects of freezing drizzle on ice accretion were analyzed for ten freezing drizzle events during a comprehensive ice thickness, fog, and precipitation observation campaign carried out during the winter of 2008 and 2009 at Enshi Radar Station (3017'N, 10916'E), Hubei Province, China. The growth rate of ice thickness was 0.85 mm h－1 during the freezing drizzle period, while the rate was only 0.4 mm h－1 without sleet and freezing drizzle. The rain intensity, liquid water content (LWC), and diameter of freezing drizzle stayed at low values. The development of microphysical properties of fog was suppressed in the freezing drizzle period. A threshold diameter (Dc) was proposed to estimate the inuence of freezing drizzle on different size ranges of fog droplets. Fog droplets with a diameter less thanDc would be affected slightly by freezing drizzle, while larger fog droplets would be affected signicantly. Dc had a correlation with the average rain intensity, with a correlation coefficient of 0.78. The relationships among the microphysical properties of fog droplets were all positive when the effect of freezing drizzle was weak, while they became poor positive correlations, or even negative correlations during freezing drizzle period. The direct contribution of freezing drizzle to ice thickness was about 14.5%. Considering both the direct and indirect effects, we suggest that freezing drizzle could act as a catalyst causing serious icing conditions.     

Urban green commons: Insights on urban common property systems

The aim of this paper is to shed new light on urban common property systems. We deal with urban commons in relation to urban green-space management, referring to them as urban green commons. Applying a property-rights analytic perspective, we synthesize information on urban green commons from three case-study regions in Sweden, Germany, and South Africa, and elaborate on their role for biodiversity conservation in urban settings, with a focus on business sites. Cases cover both formally established types of urban green commons and bottom-up emerged community-managed habitats. As our review demonstrates, the right to actively manage urban green space is a key characteristic of urban green commons whether ownership to land is in the private, public, the club realm domain, or constitutes a hybrid of these. We discuss the important linkages among urban common property systems, social–ecological learning, and management of ecosystem services and biodiversity. Several benefits can be associated with urban green commons, such as a reduction of costs for ecosystem management and as designs for reconnecting city-inhabitants to the biosphere. The emergence of urban green commons appears closely linked to dealing with societal crises and for reorganizing cities; hence, they play a key role in transforming cities toward more socially and ecologically benign environments. While a range of political questions circumscribe the feasibility of urban green commons, we discuss their usefulness in management of different types of urban habitats, their political justification and limitation, their potential for improved biodiversity conservation, and conditions for their emergence. We conclude by postulating some general policy advice.     

Mired in the past — looking to the future: Geochemistry of peat and the analysis of past environmental changes

Peat cores from ombrotrophic bogs have been used as a valuable archive to study environmental change for over a century. Much of this focus on the peat record has been on biological proxies of environmental change, such as pollen and peat-forming macrofossils, but there is growing interest in the geochemical record to study environmental changes. Several studies of long-term peat records in Europe have reconstructed past changes in atmospheric lead pollution, for example, and the general cohesiveness of the results and their agreement with known historical trends in metal production exemplify the best potential of peat geochemistry as an environmental archive. Based on the success with lead, a current emphasis in peat reconstructions is to assess the record of past mercury deposition and results thus far show generally consistent trends, e.g., a pre-anthropogenic mercury accumulation rate of about 0.5–1.5 μg Hg m^− 2 year^− 1. Despite this general consistency there is increasing concern that there may be diagenetic effects on the quantitative record of some metals, which can be inferred based on a strong relationship between mercury and other organically bound elements and proxies for peat decomposition (C/N ratio). However, it is possible that changes in decomposition and the alteration of some metal records could provide climatic information. A few recent studies show that closer examination of the geochemical matrix, in some cases along with biological proxies, can provide valuable information on landscape changes and climate; for example, partitioning metals into different weight fractions and source regions can be applied to climate studies. The best interpretations of the peat geochemical record in the context of environmental and climate change will likely come when geochemical and biological records are considered simultaneously.     

An elastoplastic model based on the shakedown concept for flexible pavements unbound granular materials

Nowadays, the problem of rutting of flexible pavements linked to permanent deformations occurring in the unbound layers is taken into account only by mechanistic empirical formulas. Finite element modelling of realistic boundary value problems with incremental rheological models will lead to unrealistic calculation time for large cycle numbers. The objective of the authors is to present a simplified model which can be used to model the flexible pavements rutting with the finite elements framework. This method is based on the shakedown theory developed by Zarka which is usually associated to materials like steels. It has been adapted for granular materials by introducing a yield surface taking into account the mean stress influence on the mechanical behaviour and a dependency of the hardening modulus with the stress state. The Drucker–Prager yield surface has been used with a non‐associated flow rule. Comparisons with repeated load triaxial tests carried out on a subgrade soil have been done. These comparisons underline the capabilities of the model to take into account the cyclic behaviour of unbound materials for roads. Finally, a discussion, dealing with the use of the simplified method within a finite element modelling of a full‐scale experiment, is presented. Copyright © 2005 John Wiley & Sons, Ltd.