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81.
基于Shuttleworth-Wallace Hu(SWH)双源蒸散模型对青藏高原那曲、纳木错、藏东南站蒸散发进行估算,在结果验证良好基础上,对青藏高原蒸散发变化特征及各站主要影响因素进行了分析。结果表明:SWH模型在青藏高原3个草甸站适用性良好;年蒸散发介于388~732 mm之间,年内分布呈先增大后减小特征;3站蒸散发组分差异较大,那曲站和纳木错站土壤蒸发对蒸散总量的贡献分别为53%和56%,藏东南站蒸散发则几乎全部由植被蒸腾贡献,占比高达95%;植被叶面积指数为3站蒸散发最主要的影响因素,饱和水汽压差对藏东南站蒸散发影响也较大。研究结果可对青藏高原蒸散发及其组分时空格局与水循环过程研究提供科学依据。 相似文献
82.
83.
???й?????????IGS????,??????FES2004????????NAO99b?????????????????????????????????λ?????????????????????????????????λ????????cm??????????????U????????????????????????3~4????????????????????????????????mm????????????????????????С????????????????GPS????????????????10-8??????????????????????????????????С??mm?????????????????????????????1 cm?? 相似文献
84.
Complex component analysis of shear-wave splitting: theory 总被引:2,自引:0,他引:2
85.
Anthropogenic activities create various contaminated leachate, which can migrate downward from the vadose zone to groundwater,
transferring contaminants, including some hazardous ones.
When these various sources of contamination influence the groundwater aquifer simultaneously, the effects of contamination
are enhanced.
The major concern of this study has been to determine whether the shape of a groundwater chlorograph might be the result of
such deterministic effects as accumulation of one or more particular processes of groundwater contamination, and how this
might relate to specific hydrological situations.
This study proposes a classification of groundwater contamination on the basis of properties of the main components of groundwater
quality graphs and the corresponding hydrogeological/environmental situation.
The study further suggests that contamination of groundwater in any hydrogeological situation (e.g. sea water) may be graphically
expressed.
A variety of chlorographs and nitrographs, representative of various groundwater aquifers sampled from a number of wells throughout
Israel attest to this.
The study thus indicates that groundwater quality graphs may be considered as a complementary tool for groundwater quality
control and better understanding aquifer situations. 相似文献
86.
A statistical study of the dependence between various critical fusion temperatures of a certain kind ofcoal and its chemical components is carried out.As well as using classical dependence techniques(multiple,stepwise and PLS regression,principal components,canonical correlation,etc.)together withthe corresponding inference on the parameters of interest,non-parametric regression and bootstrapinference are also performed. 相似文献
87.
The carbonate factories, their controlling factors and their palaeoecological and sedimentological signals recorded in sedimentary successions are key elements for understanding the evolution of carbonate platform systems. Luis Pomar has dedicated most of his academic life to the study of carbonate rocks and carbonate factories. The idea for this special issue to celebrate Pomar’s career arose during a session at the 34th International Association of Sedimentologists meeting held in Rome, entitled ‘Understanding carbonate factories through palaeoecological and geochemical signals’. The proposal encountered great response among participants, and additional contributions followed an email invitation to other specialists. This issue contains a variety of papers on carbonate sedimentology and carbonate factories. Here, an introduction that contextualizes the papers and key concepts discussed in this thematic issue is provided. It reviews Luis Pomar’s major achievements in carbonate sedimentology and discusses the evolution of the concept of the carbonate factory and the series of palaeoecological and sedimentological signals used to characterize the wide spectrum of carbonate depositional systems found in the natural world. 相似文献
88.
陈龙 《测绘与空间地理信息》2015,(5):105-108
近年来,犯罪和暴力问题已经成为人们重点关注的社会热点问题,其严重影响社会和谐以及人民日常生活质量.暴力犯罪行为可能由于多种原因引起,其中之一就是就业情况.公众普遍认为,高失业率将引发高犯罪率,因此检测就业情况与犯罪行为之间的关系就显得尤为重要.本文将主要针对不同类型犯罪行为以及总犯罪率与失业率之间的关系进行分析,以便分析其中的关系和联系.在GeoDa软件的帮助下,可以形成一系列图表来帮助得到需要的结果.暴力犯罪、毒品犯罪和入室犯罪将作为典型犯罪类型进行单独分析.从1980年开始,苏格兰政府开始进行了一系列的统计,其主要目的是检测苏格兰地区的所有基本参数以便为苏格兰研究机构提供帮助.本文基于苏格兰政府SIMD统计参数,并主要针对爱丁堡这一苏格兰政治经济中心同时也是苏格兰首府进行分析. 相似文献
89.
Quantifying the variability and allocation patterns of aboveground carbon stocks across plantation forests is central in deriving accurate and reliable knowledge and understanding of the extent to which these species contribute to the global carbon cycle and towards minimizing climate change effects. The principal objective of this study was to quantify the variability and allocation patterns of aboveground carbon stocks across Pinus and Eucalyptus plantation forests, tree-structural attributes (i.e. stems, barks, branches and leaves) and age groups, using models developed based on remotely sensed data. The results of this study demonstrate that aboveground carbon stocks significantly (α = 0.05) vary across different plantation forest species types, structural attributes and age. Pinus taeda and Eucalyptus grandis species contained aboveground carbon stocks above 110 t C ha−1, and Eucalyptus dunii had 20 t C ha−1. Across plantation forest tree structural attributes, stems contained the highest aboveground carbon stocks, when compared to barks, branches and leaves. Aboveground carbon stock estimates also varied significantly (α = 0.05) with stand age. Mature plantation forest species (i.e. between 7 and 20 years) contained the highest aboveground carbon stock estimates of approximately 120 t C ha−1, when compared to younger species (i.e. between 3 and 6 years), which had approximately 20 t C ha−1. The map of aboveground carbon stocks showed distinct spatial patterns across the entire study area. The findings of this study are important for understanding the contribution of different plantation forest species, structural attributes and age in the global carbon cycle and possible climate change moderation measures. Also, this study demonstrates that data on vital tree structural attributes, previously difficult to obtain, can now be easily derived from cheap and readily-available satellite data for inventorying carbon stocks variability. 相似文献
90.
Zheng-Gang Li Yan-Hui Dong Ji-Qiang Liu Ling Chen 《International Geology Review》2015,57(5-8):978-997
Seamounts are an integral part of element recycling in global subduction zones. The published trace element and Pb-Sr-Nd isotope data for basaltic lavas from three key segments (Central Lau Spreading Ridge (CLSR), Eastern Lau Spreading Ridge (ELSR), and Valu Fa Ridge (VFR)) of the Lau back-arc basin were compiled to evaluate the contribution of Louisville seamount materials to their magma genesis. Two geochemical transitions, separating three provinces with distinct geochemical characteristics independent of ridge segmentation, were identified based on abrupt geochemical shifts. The origin of the geochemical transitions was determined to be the result of drastic compositional changes of subduction components added into the mantle source, rather than the transition from Indian to Pacific mid-ocean ridge basalt (MORB) mantle, or due to variable mantle fertilities. The most likely explanation for the drastic shifts in subduction input is the superimposition of Louisville materials on ‘normal’ subduction components consisting predominantly of aqueous fluids liberated from the down-going altered oceanic crust and minor pelagic sediment melts. Quantitative estimation reveals that Louisville materials contributed 0–74% and 21–83% of the Th budget, respectively, to CLSR and VFR lavas, but had no definite contribution to the lavas from the ELSR, which lies farthest away from the subducted Louisville seamount chain (LSC). The spatial association of the subducted LSC with the Louisville-affected segments suggests that the Louisville signature is regionally but not locally available in the Tonga subduction zone. Besides, the preferential melting of subducted old Cretaceous LSC crust instead of the old normal Pacific oceanic crust at similar depths implies that elevated temperature across the subduction interface or seamount erosion and rupture were required to trigger melting. A wider implication of this study, thus, is that seamount subduction may promote efficiency of element recycling in subduction zones. 相似文献