Preliminary investigation of mercury in bone tissues of skua and penguin in Antarctica using AFS and Synchrotron Radiation X-ray Fluorescence （SR-XRF）   总被引：1，自引：0，他引：1  

谢周清程邦波  孙立广黄宇营 何伟 《极地研究(英文版)》2005,16(1):33-40

Mercury （Hg） was investigated in bone tissues of skua （ Catharacta maccormick） and penguin （Pygoscelis adeliae） collected in the maritime Antarctic using atomic fluorescence spectrometry （AFS） and synchrotron radiation X-ray fluorescence （SR-XRF） method. The total levels of mercury in bone tissues of penguin and skua are much lower than those in other organs （e. g. , kidney, liver）. The toxic effects of mercury in bone tissues of seabirds in polar region are not known. We have used SR- XRF method to map the distribution of trace levels of mercury in bones. The levels of mercury are found to be enriched somewhere near the periosteal surface and/or endosteal surface. The distribution of mercury shows strongly correlation with that of some essential elements and probably poses negative effect on the bone metabolism inferring from the relationship of mercury with the other elements. These studies represent a first step toward understanding the toxic effects of mercury on bone of polar animals by suggesting the possible microscopic investigation.  相似文献   

华北板块北缘活动带元古宙构造岩片   总被引：15，自引：3，他引：15  

陈跃军  彭玉鲸  路孝平  刘跃文 《吉林大学学报(地球科学版)》2002,32(2):134-139

新的研究证实 ,华北板块北缘残存一条元古宙构造岩片堆集带 ,包括古元古代、中元古代、新元古代等多期构造岩片。并相伴有 180 0Ma±、140 0Ma±、10 0 0Ma±、6 5 0Ma±的花岗岩类的侵入活动和构造变质成矿等热事件的年代记录 ,并在华北板块北部金镶边带中保存了相一致的信息 ,揭示了它们是陆缘多期拼贴造山的产物。这为超大陆旋回 ,特别是元古宙两次超大陆的聚合与裂解及其构造演化过程的研究提供了良好的野外实验园地 ,并为元古宙、特别是古元古代大陆的增生及Rodinia超大陆在北半球的存在或构造响应提出新的课题。  相似文献   

X线侧位片与高分辨率CT对鼻骨骨折的对比研究   总被引：17，自引：0，他引：17  

王惠芝  孙璐  闫罡  曾庆玉 《CT理论与应用研究》2002,11(3):33-38

目的　通过86例鼻骨骨折的鼻骨X线侧位片与高分辨率CT(HRCT）对比研究，确定HRCT检查对鼻骨骨折的诊断价值。材料与方祛　86例鼻外伤或/和He、面外伤的患者均进行了鼻骨X线侧位摄影、HRCT扫描检查，经集体讨论，由有经验的放射医师对全部影像资料进行分析并进行统计学处理。结果HRCT显示所有的86例鼻骨骨折，但在此86例骨折中X线平片只显示了35例阳性，包括15例鼻骨汇合部骨折，7例双侧鼻骨骨折，3例复合骨折(鼻骨汇合部及双侧鼻骨骨折)，l0例鼻区骨折。X线平片显示5l例为阴性。结论　对鼻骨骨折的诊断，HRCT明显优于鼻骨X线侧位片，HRCT扫描检查可提高X线隐性鼻骨骨折的诊断，并可明确鼻骨骨折的类型、范围和程度，为临床诊断和治疗提供可靠的依据。  相似文献   

CT长骨测量在骨折髓内钉固定术中的应用     

王越  徐均超  高艳 《CT理论与应用研究》2003,12(2):33-35

目的：探讨CT在长骨测量中的应用价值.方法：经X线检查证实的肱骨、股骨、胫骨骨折患者600多例，其中302例临床行髓内钉固定术，并在术前进行了健侧骨的CT定位扫描，测量其两点之间骨干长度及骨髓腔最窄处的宽度。结果 依据术前CT定位测量数据而选择的髓内钉在手术中完全适用。结论：此方法操作简便测量数据准确为临床提供可靠依据。  相似文献   

U—Series Dating of Fossil Bones：Results from Chinese Sites and Discussions on Its Reliability     

沈冠军 《中国地球化学学报》1996,15(4):303-313

Calculations,according to some open-system models,point out that while a statistically significant discrepancy between the results of two U-series methods,^230Th/^234U and ^227Th/^220Th(or ^231Pa/^235U),attests a relatively recent and important uranium migration,concordant dates cannot guarantee closes-system behavior of sample.The results of 20 fossil bones from 10 Chinese sites,19 of which are determined by two U-series methods,are given,Judging from independent age controls,8 out of the 11 concordant age sets are unacceptable,The results in this paper suggest that uranium may cycle into or out of fossil bones,such geochemical events may take place at any time and no known preserving condition may securely protect them from being affected.So for the sitew we have studied,the U-series dating of fossil bones is of limited reliability.  相似文献   

A Rhaetian microvertebrate fauna from Stowey Quarry,Somerset, U.K.     

Iacopo Cavicchini  H. Cecilia Heyworth  Christopher J. Duffin  Claudia Hildebrandt  Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):144-158

Rhaetian bone beds have been described from many locations in south-west England, around Bristol. One site that has never been reported is Stowey Quarry, some 13?km south of Bristol. This quarry yielded Lias, and revealed thin Rhaetian units in the quarry floor, including two bone beds, the basal Rhaetian bone bed, and a second, higher bone bed, also within the Westbury Formation. The fossil fauna of both includes elements typical of Rhaetian bone beds elsewhere, but showing differences in faunal composition between the two. The basal bone bed yielded more specimens and more species, with three taxa (Sargodon tomicus, Rhomphaiodon minor and Hybodus cloacinus) exclusive to this bed and eleven identified in total. Severnichthys acuminatus accounts for more than 50% of the countable teeth from the basal bone bed, followed by Gyrolepis albertii with 20%, Lissodus minimus with 14% and Rhomphaiodon minor with 9%. The basal bone bed, as ever, is dominated by chondrichthyans, whereas the upper bone bed is dominated by osteichthyans, which form 90% of the non-dental remains. The only unique taxon is Dapedium, and Gyrolepis albertii is the most abundant species with 45% of countable teeth, followed by Severnichthys acuminatus with 38% and Duffinselache holwellensis with 11%. These faunal differences, and the equally good condition of specimens between both samples confirms that the upper bone bed is independent of the basal bone bed, and is not a reworked subsample.  相似文献   

基于相干特征的岩石薄片序列图像边缘提取及颗粒分割     

周恒  张春雷  张欣  陈庆轩  张艳  仲诚诚 《吉林大学学报(地球科学版)》2021,51(6):1897-1907

针对岩石颗粒边缘模糊、结构复杂的特点,为了更有效地识别颗粒边缘,在基于特征值的C3相干算法的基础上,融合多尺度和多角度的特征表达,提出了一种改进的C3相干算法。该算法综合考虑岩石薄片图像角度域光学特征、空间尺度信息和各向异性信息,能更有效地表征颗粒边缘特征,表现出对复杂矿物结构的适应能力。在采集的岩石薄片正交偏光图像上验证提出的算法,实验结果表明,与原生C3相干算法相比,改进后的C3相干算法在全局图像上的方差和灰度差分乘积分别提升了68.41%和22.91%,信息熵下降了21.61%。  相似文献   

化脓性脊柱炎影像学诊断(附23例分析)     

唐桂长  郝明珠  王月训 《CT理论与应用研究》1993,(4)

笔者报告了23例化脓性脊柱炎。本文着重分析对比了X线平片和CT检查结果,通过分析对比,发现CT检查优于X线平片,并有助于对化脓性脊柱炎早期作出诊断。主要影像学表现:早期,软组织肿胀和脓肿形成,骨质呈虫蚀状破坏,随之破坏区周围出现增生硬化。CT 还能发现炎块中的气体。晚期,骨质修复占优势,即骨质增生硬化,骨桥形成,最后可产生骨性融合。  相似文献   

化脓性脊柱炎影像学诊断（附23例分析）     

房桂云  郝明珠 《CT理论与应用研究》1995,4(1):46-50

笔者报告了２３例化脓性脊柱炎。本文着重分析对比了Ｘ线平片和ＣＴ检查结果，通过分析对比，发现ＣＴ检查优于Ｘ线平片，并有助于对化脓性脊柱炎早期作出诊断。主要影像学表现：早期，软组织肿胀和脓肿形成，骨质呈虫蚀状破坏，随之破坏区周围出现增生硬化。ＣＴ还能发现炎块中的气块，晚期骨修复占优势，即骨质增生硬化，骨桥形成，最后可产生骨性融合。  相似文献   

模式识别在手腕骨自动识别中的应用研究     

杨挺  刘友光  黄幼才 《武汉大学学报(信息科学版)》1998,(1)

手腕骨自动识别是实现骨龄评定自动化的关键。以数字化仪采集数据为基础,研究了模式识别与模糊数学在手腕骨自动识别中的应用理论和方法。实验证明,模式识别的应用是成功的。  相似文献