PCDD and PCDF intake through consumption of locally produced seafood by Venice lagoon residents: elements for risk management     

Miniero R  Ceretti G  Cherin E  Dellatte E  De Luca S  Ferri F  Fulgenzi AR  Grim F  Iacovella N  Iamiceli AL  Ingelido AM  Vio P  di Domenico A 《Marine pollution bulletin》2005,50(12):1727-1732

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Developing a Radiative Shock Experiment Relevant to Astrophysics     

Shigemori K  Ditmire T  Remington BA  Yanovsky V  Ryutov D  Estabrook KG  Edwards MJ  MacKinnon AJ  Rubenchik AM  Keilty KA  Liang E 《The Astrophysical journal》2000,534(2):L159-L162

We assume that internal shocks of gamma-ray bursts (GRBs) consist of multiple sub-jets with a collimation half-angle of about several times gamma-1i, where gammai is the Lorentz factor of each sub-jet. If by chance a sub-jet is first emitted off-axis from the line of sight, the observed peak energy can be in the X-ray region. Next, if by chance a subsequent sub-jet is emitted along the line of sight, then the peak energy will be in the gamma-ray region and the gamma ray may arrive after the X-ray precursor from the former sub-jet depending on parameters. This model predicts a new class of GRBs with extremely weak and short gamma-ray emission but X-ray precursors and/or postcursors as well as an afterglow.  相似文献   

用台阵资料研究地震散射     

Dain.  AM 黄金莉 《世界地震译丛》2000,(3):55-66

应用高频地震台阵资料我们能研究频带１～１０Ｈz同伯地震波场空间和时间的特征。作者 对ＮＯＲＥＳＳ、ＦＩＮＥＳＡ和ＡＲＣＥＳＳ的地震波散射进行了研究。研究应用了两种主要方法,即尾波的频率－波数分析和地震相位的相干性分析。对区域地震记录,Ｌg尾波的频率－波数分析表明Ｌg到Ｌg的散射是主要的,且散射开始集中在正向,在尾波的后面变成了均匀的反射散射。Ｐ尾波的情况更加复杂,尽管研究的所有情况表明能量是集中的方位  相似文献   

非物质文化遗产旅游开发风险评价——以天津市为例     

李烨  王庆生  李志刚 《地域研究与开发》2014,(5)

在对非物质文化遗产旅游开发风险识别的基础上,通过模糊评价法建立多级模糊综合评价模型,对天津传统表演艺术、工艺美术和民俗三类主要的非物质文化遗产旅游开发风险进行评价。天津非物质文化遗产旅游开发风险整体处于较低水平,适宜旅游开发;不同类型的非物质文化遗产旅游开发风险不同,民俗类旅游开发风险最高,工艺美术类次之,传统表演艺术类最低;三类非物质文化遗产旅游开发的客体风险都很高,环境风险相对较低,主体风险最低。在开发过程中应对不同类型的非物质文化遗产的各类风险予以不同程度的关注。  相似文献   

Assessment of phosphogypsum impact on the salt-marshes of the Tinto river (SW Spain): role of natural attenuation processes   总被引：2，自引：0，他引：2  

Pérez-López R  Castillo J  Sarmiento AM  Nieto JM 《Marine pollution bulletin》2011,62(12):2787-2796

About 120 Mton of phosphogypsum from the fertiliser industry were stack-piled on the salt-marshes of the Tinto river (Spain). This paper investigates the capacity of salt-marshes to attenuate contamination due to downward leaching from phosphogypsum. Solids and pore-waters were characterized at different depths of the pile to reach the marsh-ground. In superficial zones, metals were highly mobile, and no reduced sulphur was found. However, pollutant concentration decreased in the pore-water in deeper oxygen-restricted zones. Metal removal occurred by precipitation of newly formed sulphides, being this process main responsible for the contamination attenuation. Pyrite-S was the main sulphide component (up to 2528 mg/kg) and occurred as framboids, leading to high degrees of pyritization (up to 97%). The sulphidization reaction is Fe-limited; however, excess of acid-volatile sulphide over other metals cause precipitation of other sulphides, mainly of Cu and As. This decrease in metal mobility significantly minimises the impact of phosphogypsums on the salt-marshes.  相似文献   

An obsolete dichotomy? Rethinking the rural–urban interface in terms of food security and production in the global south     

Lerner AM  Eakin H 《The Geographical journal》2011,177(4):311-320

The global food system is coming under increasing strain in the face of urban population growth. The recent spike in global food prices (2007–08) provoked consumer protests, and raised questions about food sovereignty and how and where food will be produced. Concurrently, for the first time in history the majority of the global population is urban, with the bulk of urban growth occurring in smaller-tiered cities and urban peripheries, or ‘peri-urban’ areas of the developing world. This paper discusses the new emerging spaces that incorporate a mosaic of urban and rural worlds, and reviews the implications of these spaces for livelihoods and food security. We propose a modified livelihoods framework to evaluate the contexts in which food production persists within broader processes of landscape and livelihood transformation in peri-urban locations. Where and how food production persists are central questions for the future of food security in an urbanising world. Our proposed framework provides directions for future research and highlights the role of policy and planning in reconciling food production with urban growth.  相似文献   

利用综合植物指标进行作物估产的初步研究     

XuemeiBai  ShurjiMurai  王庆生 《地理科学进展》1991,10(3):60-64

研究介绍近年来,使用卫星遥感数据进行作物估产的研究已显得十分重要。土地资源卫星广泛应用于这一领域。但是,对于大尺度的作物估产来说,NOAA 综合植物指标(地表绿色植物叶绿素含量指标)数据较之其它卫星数据具有更大的优越性。  相似文献   

山东临邑县冬小麦播期播量气象条件实验分析     

王世刚  王庆生 《贵州气象》2013,37(3):45-46

该文选用泰农18(中大穗)、济麦22(多穗)两个冬小麦品种,在2011年9月26日—10月20日采取5个不同播期,3个不同播量进行田间播期播量试验,以期筛选出本地区不同品种类型冬小麦的适宜播期、适宜播量。为充分利用临邑县气候资源和制定合理的小麦播期播量提供依据。  相似文献   

Terrestrial pollutant runoff to the Great Barrier Reef: An update of issues, priorities and management responses   总被引：1，自引：0，他引：1  

Brodie JE  Kroon FJ  Schaffelke B  Wolanski EC  Lewis SE  Devlin MJ  Bohnet IC  Bainbridge ZT  Waterhouse J  Davis AM 《Marine pollution bulletin》2012,65(4-9):81-100

The Great Barrier Reef (GBR) is a World Heritage Area and contains extensive areas of coral reef, seagrass meadows and fisheries resources. From adjacent catchments, numerous rivers discharge pollutants from agricultural, urban, mining and industrial activity. Pollutant sources have been identified and include suspended sediment from erosion in cattle grazing areas; nitrate from fertiliser application on crop lands; and herbicides from various land uses. The fate and effects of these pollutants in the receiving marine environment are relatively well understood. The Australian and Queensland Governments responded to the concerns of pollution of the GBR from catchment runoff with a plan to address this issue in 2003 (Reef Plan; updated 2009), incentive-based voluntary management initiatives in 2007 (Reef Rescue) and a State regulatory approach in 2009, the Reef Protection Package. This paper reviews new research relevant to the catchment to GBR continuum and evaluates the appropriateness of current management responses.  相似文献   

(137)Cs baseline levels in the Mediterranean and Black Sea: a cross-basin survey of the CIESM Mediterranean Mussel Watch programme     

Thébault H  Rodriguez Y Baena AM  Andral B  Barisic D  Albaladejo JB  Bologa AS  Boudjenoun R  Delfanti R  Egorov VN  El Khoukhi T  Florou H  Kniewald G  Noureddine A  Patrascu V  Pham MK  Scarpato A  Stokozov NA  Topcuoglu S  Warnau M 《Marine pollution bulletin》2008,57(6-12):801-806

The common mussel Mytilus galloprovincialis was selected as unique biomonitor species to implement a regional monitoring programme, the CIESM Mediterranean Mussel Watch (MMW), in the Mediterranean and Black Seas. As of today, and upon standardization of the methodological approach, the MMW Network has been able to quantify (137)Cs levels in mussels from 60 coastal stations and to produce the first distribution map of this artificial radionuclide at the scale of the entire Mediterranean and Black Seas. While measured (137)Cs levels were found to be very low (usually < 1 Bq kg(-1) wet wt) (137)Cs activity concentrations in the Black Sea and North Aegean Sea were up to two orders of magnitude higher than those in the western Mediterranean Basin. Such effects, far from representing a threat to human populations or the environment, reflect a persistent signature of the Chernobyl fallout in this area.  相似文献