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91.
Surface sediment and biota were collected from 12 sampling sites – seven along the Pearl River Delta and five along the Hong Kong coastline. Perfluorinated compound (PFC) concentrations were detected using a high-performance-liquid-chromatogram–tandem-mass-spectrometry system. Analytical results indicated that the total PFC concentrations were in the range of 0.15–3.11 ng/g dry weight in sediments, while the total PFC concentrations in oyster and mussel samples were between 0.46–1.96 and 0.66–3.43 ng/g wet weight, respectively. The major types of PFCs detected in the sediment samples were perfluorooctanesulfonic acid (PFOS) and perfluorobutanoic acid (PFBA), with concentrations ranging from low limits of quantification to 0.86 ± 0.12 ng/g dry weight and 1.50 ± 0.26 ng/g dry weight, respectively. In bivalve samples, PFOS was the dominant contaminant with concentrations ranging from 0.25 ± 0.09 to 0.83 ± 0.12 ng/g wet weight in oysters and 0.41 ± 0.14 to 1.47 ± 0.25 ng/g wet weight in mussels. An increase in PFC concentration was found to be correlated with increased human population density in the study areas.  相似文献   
92.
A new genus with one new species and five new species of genus Amblomma of fossil ommatids are described and illustrated: Euryomma tylodes gen. et sp. nov., Amblomma cyclodonta sp. nov., Amblomma miniscula sp. nov., Amblomma porrecta sp. nov., Amblomma eumeura sp. nov., and Amblomma protensa sp. nov. All of them were collected from the Upper Jurassic or Lower Cretaceous Yixian Formation of western Liaoning, China. A key to the species of Amblomma is given. The wide epipleural space shows that Euryomma may be a primitive genus in Ommatidae. Many different species of Amblomma occurred within the same sedimentary horizon in this area could be environmental changes caused by frequent volcanic activities during the deposition of the Yixian Formation.  相似文献   
93.
Six polycyclic musk compounds [Cashmeran (DPMI), Celestolide (ADBI), Phantolide (AHMI), Traseolide (ATII), Tonalide (AHTN), and Galaxolide (HHCB)] were analysed in marine green-lipped mussels (Perna viridis) from Hong Kong. ADBI, HHCB and AHTN were detected in almost all samples, while AHMI, ATII and DPMI were not detected. Concentrations of ADBI, HHCB and AHTN in mussels ranged from below detection limit–0.0743 (mean: 0.0246), 0.247–6.08 (mean: 1.15) and 0.0591–0.738 (mean: 0.190) mg/kg lipid weight, respectively. Mussels from two sampling sites in central Victoria Harbour contained the highest total polycyclic musk levels, suggesting that these waters are heavily influenced by domestic sewage. Concentrations of HHCB and AHTN detected in the mussel samples were the second highest and the highest levels, respectively, compared to global concentrations. A preliminary risk assessment indicated that HHCB and AHTN in mussels pose little or no threat to the health of shellfish consumers. Nevertheless, more comprehensive studies are required to further assess the ecological and human health risks associated with polycyclic musks.  相似文献   
94.
The authors reassessed the taxonomic distinction of Iteravis huchzermeyeri and Gansus zheni, which are two species of Ornithuromorpha based on specimens from the same locality in western Liaoning and derive from the Jehol Biota. The detailed comparisons of the holotype and referred specimens of both species, reveal no anatomical features that distinguish these taxa as separate species. Some minor differences are considered to relate to ontogenetic or interspecific differences. The stratigraphic occurrence for both specimens is the Lower Cretaceous Jiufotang Formation. Accordingly, the authors conclude that Iteravis huchzermeyeri has priority, by 15 days, for this taxon and that Gansus zheni is a junior synonym. The diagnosis of Iteravis huchzermeyeri is revised based on further study on all specimens referred to this species. Its generic distinction from Gansus is maintained thereby removing a potential genus-level correlation linking Xiagou Formation in Gansu Province with the Jiufotang Formation in Liaoning Province.  相似文献   
95.
Perfluorinated alkyl compounds (PFCs) including perfluorooctane sulphonate (PFOS) and perfluorooctanoate (PFOA) were measured in environmental samples collected from around Homebush Bay, an urban/industrial area in the upper reaches of Sydney Harbour and Parramatta River estuary. Water, surface sediment, Sea Mullet (Mugil cephalus), Sydney Rock Oyster (Saccostrea commercialis) and eggs of two bird species; White Ibis (Threskiornis molucca), and Silver Gull (Larus novaehollandiae) were analysed. In most samples PFOS was the dominant PFC. Geometric mean PFOS concentrations were 33 ng/g ww (wet weight) in gull eggs, 34 ng/g ww in ibis eggs, and 1.8 ng/g ww and 66 ng/g ww in Sea Mullet muscle and liver, respectively. In sediment the PFOS geometric mean was 1.5 ng/g, in water average PFOS and PFOA concentrations ranged from 7.5 to 21 ng/L and 4.2 to 6.4 ng/L, respectively. In oysters perfluorododecanoic acid was most abundant, with a geometric mean of 2.5 ng/g ww.  相似文献   
96.
对西天山石炭纪地层及生物群的一些认识   总被引:1,自引:0,他引:1  
张建东 《新疆地质》2012,30(Z1):38-44
据前人资料结合1∶25万区调新资料研究成果,对西天山石炭纪典型岩石地层单位及时代、基本特征形成一些新的认识.对新疆北部石炭系腕足“管孔石燕动物群”、“安加拉植物群”及腕足“拟穆武贝动物群”的分布范围、生物区系意义进行总结和讨论.利用多年来西天山陆续发现的菊石化石,建立了本区7个石炭纪菊石带,并结合“R带”为主的菊石化石资料对西天山上、下石炭统年代界线进行讨论.  相似文献   
97.
Yanjiahella gen. nov., a distinctive fossil taxon from the Early Cambrian Yanjiahe Biota in Yichang, Hubei Province, is characterized by: 1) an overall body plan composed of a stalk and a calyx (also arms in some species); 2) a stalk with closely spaced, transverse wrinkles and a medial, longitudinal ridge; and 3) a calyx preserved with three-dimensional radiating striations, as well as a probable madreporite in some specimens. Three species that can be assigned to this genus, which are Y. ancarpa sp. nov., Y. monocarpa sp. nov., and Y. biscarpa sp. nov. Yanjiahella is comparable to certain echinoderm taxa in terms of morphology and some biological structures, which might indicate the early evolution and diversification of ancestral echinoderm lineages from the early Early Cambrian Yangtze Platform. The discovery of putative echinoderms in the Yanjiahe Biota provides significant clues about the origination and evolution of the deuterostome phylum Echinodermata.  相似文献   
98.
The early Aptian abrupt carbon isotope excursion in marine carbonate and sedimentary organic matter reflects a major perturbation in the global carbon cycle. However, until now almost all the evidences of this event came from marine deposits. Here we present organic-carbon isotope (δ13Corg) data from the non-marine Jehol Group in western Liaoning, China. The lacustrine δ13Corg curve is marked by a relative long-lasting δ13Corg minimum followed by two stages of positive δ13Corg excursions that are well correlated with contemporaneous marine records. The carbon isotope correlation shows that the lacustrine strata of the Jehol Group were deposited at the same time of the early Aptian Oceanic Anoxic Event (OAE1a). The relative long-lasting δ13Corg minimum supports the hypothesis that volcanic CO2 emission may have played the main role in triggering the negative δ13C excursion and global warming at the onset of this event. In addition, the onset of δ13Corg minimum is concomitant with the radiation of the Jehol Biota, implying that the evolutionary radiation of the Jehol Biota may have been closely related with the increase in atmospheric CO2 and temperature.  相似文献   
99.
<正>The Early Cretaceous Jehol biota of northeastern China contains a diverse group of notostracans, including two genera,Chenops and Jeholops,described here.Chenops is characterized by a combination of an ovate carapace,narrow anal plate,equant distal endites and endopod on the anterior thoracic limbs.In addition to the new species,Chenops yixianensis,the genus also provisionally includes Prolepidurus oblongus Oleynikov, 1968.Jeholops,however,is monotypic,represented by the new species Jeholops hongi.It is characterized by a combination of kazacharthran and notostracan features unique to this taxon.Both new genera are provisionally placed in the taxon Notostraca.More detailed work exploring the morphology of exceptionally-preserved branchiopod crustaceans is needed.The difficulties in placing fossil notostracans into a phylogenetic framework are discussed.  相似文献   
100.
中国东北区中生代生物群特征简述   总被引:1,自引:0,他引:1  
概要的总结了东北区中生代地层中古生物群,以及它们在岩石地层单位中的分布,借以说明岩石地层的时代,为地层多重划分对比提供了依据。  相似文献   
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