Place,culture, and peace; treaty cities and national culture in mediating contemporary international disputes     

Stanley D. Brunn  Vaseema Nooruddin  Kimberly Sims 《GeoJournal》1996,39(4):331-343

Many changes in the political map are the result of negotiation between disputing states. Those discussions are held in states acceptable to the parties themselves and in sites selected by the host. Two significant cultural and political features of those discussions are the selection of the treaty site and the negotioting styles of the disputing parties and negotiator. We examine these themes with examples and suggest their importance in regional and global peace processes.  相似文献   

雪地上的森林冠层混合反照率模型   总被引：2，自引：0，他引：2  

蒋玲梅  杨华  王锦地  李小文  Kimberly J. Schaudt 《遥感学报》2003,7(6):433-439

反照率通常定义为出射与入射的能量之比，是地表能量平衡中的关键因子。气候变化对反照率也很敏感。典型的气候变化预测是通过GCM与地表模型的结合进行的。目前在地表模型(如BATS模型)中，是通过空气动力学粗糙度Z0与降雪深度d两个参数来估计雪地上树冠的反照率的。在他们的工作基础上，重点考虑对于不同的太阳天顶角，直入一扇出反照率的方向性及其与叶面积指数(LAI)的关系。同时，为了保持BATS模型所需反照率模型的基本特征，主要在几何光学-辐射传输混合模型(GORT)的基础上做了一些近似来达到此目的。最后，以针叶林为例，用MODIS的反照率数据和BOREAS地面观测数据做了初步的模型验证。结果显示模型较符合实际情况。  相似文献   

THE IMPACT OF METAL AND ORGANIC CONTAMINANTS ON THE STRUCTURE OF PERIPHYTON IN LOTIC SEDIMENTS: OBSERVATIONS AT VARIOUS SCALES     

Jill A. KOSTEL  Kimberly A. GRAY  Ann L. St. AMAND 《国际泥沙研究》2003,(2)

1 INTRODUCTION While wastewater discharge regulations have significantly reduced water column pollution, historical and accidental releases of organic pollutants and heavy metals continue to pose an ecological threat as these contaminants have become 搃n-place?sediment pollutants. It had been previously assumed that natural attenuation processes, such as burial or biodegradation, would decrease the contamination levels in surface sediments and, thus, diminish the environmental impact of t…  相似文献   

Probabilistic demand and fragility assessment of welded column splices in steel moment frames          下载免费PDF全文

Carmine Galasso  Kimberly Stillmaker  Christian Eltit  Amit Kanvinde 《地震工程与结构动力学》2015,44(11):1823-1840

An assessment of seismic demands and capacities of welded column splice (WCS) connections in steel moment frames is presented. For demand assessment, nonlinear dynamic analyses are conducted for two case‐study buildings, that is, a 4‐story and a 20‐story moment frame. Results from the nonlinear dynamic analyses are assessed through a probabilistic seismic demand analysis (PSDA) framework to characterize recurrence rates of longitudinal flange stress in these connections. The PSDA is applied in two contexts. First, in the context of WCS connections constructed prior to the M 6.7 1994 Northridge earthquake, the PSDA is combined with sophisticated finite element‐based fracture mechanics analysis to compute the mean annual frequencies of fracture in these connections. The pre‐Northridge WCS are especially critical because they feature partial joint penetration and brittle materials that compromise their resistance to fracture. The analysis indicates that the mean annual frequencies of fracture in these connections may be unacceptably high for both the 4‐story and the 20‐story frames. This warrants a serious and urgent consideration of retrofit strategies. These findings are attributed to the brittleness of the pre‐Northridge splices (as indicated by the fracture mechanics simulations), as well as the force‐controlled nature of these components, wherein low‐intensity ground motions contribute disproportionately to fracture risk, as evidenced by fracture risk disaggregation. Second, in the context of new construction, the PSDA provides meaningful stress magnitudes for design. Currently, WCS connections employ complete joint penetration welds with the intent to develop the smaller column flange in yielding. The PSDA conducted in this study suggests that this requirement may be too stringent because stress demands in the splices corresponding even to high return periods (e.g., 2475 years) are significantly lower (~40 ksi), as compared with the stress required to yield the column (~55 ksi). Limitations of the study are outlined. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Is Climate Change Shifting the Poleward Limit of Mangroves?     

Sharyn M. Hickey  Stuart R. Phinn  Nik J. Callow  Kimberly P. Van Niel  Jeff E. Hansen  Carlos M. Duarte 《Estuaries and Coasts》2017,40(5):1215-1226

Ecological (poleward) regime shifts are a predicted response to climate change and have been well documented in terrestrial and more recently ocean species. Coastal zones are amongst the most susceptible ecosystems to the impacts of climate change, yet studies particularly focused on mangroves are lacking. Recent studies have highlighted the critical ecosystem services mangroves provide, yet there is a lack of data on temporal global population response. This study tests the notion that mangroves are migrating poleward at their biogeographical limits across the globe in line with climate change. A coupled systematic approach utilising literature and land surface and air temperature data was used to determine and validate the global poleward extent of the mangrove population. Our findings indicate that whilst temperature (land and air) have both increased across the analysed time periods, the data we located showed that mangroves were not consistently extending their latitudinal range across the globe. Mangroves, unlike other marine and terrestrial taxa, do not appear to be experiencing a poleward range expansion despite warming occurring at the present distributional limits. Understanding failure for mangroves to realise the global expansion facilitated by climate warming may require a focus on local constraints, including local anthropogenic pressures and impacts, oceanographic, hydrological, and topographical conditions.  相似文献   

Mo and U Isotope Evidence of Ocean Euxinia during the End-Permian Mass Extinction     

Juan Carlos SILVA-TAMAYO  Stefan WEYER  Paul B. WIGNALL  Jonathan L. PAYNE  Robert J.NEWTON  Nadjia NEUBERT  Annika BRUESKE  Kimberly LAU  Katharine MAHER 《《地质学报》英文版》2013,87(Z1):903-903

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Effects of land-cover and watershed protection futures on sustainable groundwater management in a heavily utilized aquifer in Hawai‘i (USA)     

Bremer  Leah L.  Elshall  Ahmed S.  Wada  Christopher A.  Brewington  Laura  Delevaux  Jade M.S.  El-Kadi  Aly I.  Voss  Clifford I.  Burnett  Kimberly M. 《Hydrogeology Journal》2021,29(5):1749-1765

Hydrogeology Journal - Groundwater sustainability initiatives, including sustainable yield and watershed policy protection policies, are growing globally in response to increasing demand for...  相似文献   

Pristinity and petrogenesis of eucrites     

Jasmeet K. Dhaliwal  James M. D. Day  Kimberly T. Tait 《Meteoritics & planetary science》2023,58(2):275-295

New petrography, mineral chemistry, and whole rock major, minor, and trace element abundance data are reported for 29 dominantly unbrecciated basaltic (noncumulate) eucrites and one cumulate eucrite. Among unbrecciated samples, several exhibit shock darkening and impact melt veins, with incomplete preservation of primary textures. There is extensive thermal metamorphism of some eucrites, consistent with prior work. A “pristinity filter” of textural information, siderophile element abundances, and Ni/Co ratios of bulk rocks is used to address whether eucrite samples preserve endogenous refractory geochemical signatures of their asteroid parent body (i.e., Vesta), or could have experienced exogenous impact contamination. Based on these criteria, Cumulus Hills 04049, Elephant Moraine 90020, Grosvenor Range 95533, Pecora Escarpment 91245, and possibly Queen Alexander Range 97053 and Northwest Africa 1923 are pristine eucrites. Eucrite major element compositions and refractory incompatible trace element abundances are minimally affected by metamorphism or impact contamination. Eucrite petrogenesis examined through the lens of these elements is consistent with partial melting of a silicate mantle that experienced prior metal–silicate equilibrium, rather than as melts associated with cumulate diogenites. In the absence of the requirement of a large-scale magma ocean to explain eucrite petrogenesis, the interior structure of Vesta could be more heterogeneous than for larger planetary bodies.  相似文献