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黄土滑坡稳定性评价的反演分析 总被引:2,自引:0,他引:2
本文根据黄土滑坡的变形监测结果,同时考虑了边坡的初期应变分布状况,通过有限元反分析法,反推出边坡地基的力学参数,为黄土滑坡的稳定性评价和预报提供了可靠的依据。 相似文献
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对浙江省金华市义乌江采集的边滩沉积物柱样,进行了系统的环境磁学、粒度、地球化学分析,以探讨环境磁学方法诊断河流沉积物重金属污染的可行性.结果表明,柱样磁性特征由亚铁磁性矿物主导,其垂向变化受到粒度和早期成岩作用的一定影响.柱样中重金属Cr、Ni、Cu、Zn、Cd、Pb含量及其富集因子除底部外,自下而上呈增加趋势,指示了柱样上部存在人为来源的重金属污染.柱样沉积物磁性特征与重金属含量及其富集因子的垂向变化存在相似性,其中磁化率(χ)、频率磁化率(χfd%)和硬剩磁(HIRM)与Cr、Cu、Zn、Cd、Pb的含量具有显著的正相关关系,反映了磁性矿物与重金属具有相同的来源,或者细颗粒磁性矿物对重金属的吸附作用.上述结果表明,磁学方法可用于指示义乌江的重金属污染.但由于义乌江属于开放性的河流环境系统,磁性特征变化受多重因素影响,增加了利用磁学手段定量诊断重金属污染的复杂性. 相似文献
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Monica?R.?LaraEmail author David?L.?Jones Zhongxing?Chen John?T.?Lamkin Cynthia?M.?Jones 《Marine Biology》2008,153(3):235-248
Juvenile gray snapper, Lutjanus griseus, are believed to use bays and estuaries in southern Florida as nurseries before moving out to the adjoining reef tract as
adults. Using high-resolution sector field-inductively coupled plasma-mass spectrometry (SF-ICP-MS), the elemental chemistry
of the otoliths of juveniles from five nursery regions was resolved by establishing elemental “signatures” for each region.
In this study we simultaneously analyzed 32 elements including a suite of rare earth elements. A stepwise variable selection
procedure retained a subset of eight elements that contributed substantially to separating otolith samples, including two
rare earth elements; this is one of the first studies in which rare earth elements in otoliths have contributed to separation
of fish stocks. The classification success rate in assigning fishes to the correct region of origin was 82%. Resolution of
sites less than 10 km apart suggested high site fidelity in juvenile gray snapper and little mixing of water masses between
sites. The juvenile nursery signatures will be used to determine the relative contribution of different nurseries to the adult
population on an adjoining reef tract. 相似文献
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Xu Y Wu Z Yu B Peng X Yu G Wei Z Wang G Li R 《Environmental pollution (Barking, Essex : 1987)》2008,156(1):162-167
It is well known that several morphospecies of Microcystis, such as Microcystis aeruginosa (Kützing) Lemmermann and Microcystis viridis (A. Brown) Lemmermann can produce hepatotoxic microcystins. However, previous studies gave contradictory conclusions about microcystin production of Microcystis wesenbergii (Komárek) Komárek. In the present study, ten Microcystis morphospecies were identified in waterblooms of seven Chinese waterbodies, and Microcystis wesenbergii was shown as the dominant species in these waters. More than 250 single colonies of M. wesenbergii were chosen, under morphological identification, to examine whether M. wesenbergii produce hepatotoxic microcystin by using multiplex PCR for molecular detection of a region (mcyA) of microcystin synthesis genes, and chemical analyses of microcystin content by ELISA and HPLC for 21 isolated strains of M. wesenbergii from these waters were also performed. Both molecular and chemical methods demonstrated that M. wesenbergii from Chinese waters did not produce microcystin. 相似文献
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本文采用工程地质勘察方法,揭示韩城电厂边坡的变形机理,并用弹塑性有限元对边坡进行了稳定分析,取得了与实测变形值一致的结果。 相似文献
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Dynamic Changes and Optimal Allocation of Arable Land Conversion in Transition of Jiangsu province 总被引:1,自引:0,他引:1
With the rapid development of economy and urbanization, there is more need for land, and that the arable land faces the paradox of allocation in the agricultural sector and nonagricultural sector. How to optimally allocate land in the agricultural sector and nonagricultural sector has become an important issue. This article tries to analyze the change of arable land in Jiangsu, and then uses the MAC model to get the optimal amount of arable land that can be changed, so that we can make a deadline for protecting the arable land and come up with a method for optimal allocation. 相似文献
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Yang Liu Wenhua Tan Xingqiang Wu Zhongxing Wu Gongliang Yu Renhui Li .Key Laboratory of Aquatic Biodiversity Conservation Biology 《环境科学学报(英文版)》2011,(1)
A water bloom sample collected from Lake Dishui in Shanghai was characterized.The morphological identification showed that Micorcystis wesenbergii and Micorcystis smithii were the main component of the bloom.Five strains of M.smithii were successfully isolated.Their 16S rRNA gene sequences based phylogenetic tree showed that the five strains of M.smithii intermixed with strains of other morphospecies in Microcystis.A fragment of mcy gene encoding for microcystin synthetase was detected in one of the five M.... 相似文献