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121.
邵楠  裴翀  刘传才  周薇  张乐坚  李巍 《气象科技》2013,41(6):993-997
对雷达产品的实时监控是中国气象局气象探测中心运行监控实时业务工作的重要内容之一,因此实现自动化识别雷达异常产品具有重要的现实意义和研究价值。论述基于图像处理技术实现自动识别雷达异常产品,详细介绍系统实现模型及雷达数据异常自动识别算法,其中主要阐述了特征提取、迭代学习器等相关内容。通过对检测出的雷达产品异常产品分析表明,基于图像处理技术的雷达产品异常自动识别系统可以高效的、实时的检测出异常雷达产品,便于技术人员快速发现雷达异常并及时修复,也可作为雷达维修或雷达升级改造的依据,提高雷达的使用效率。  相似文献   
122.
Twenty years after the Exxon Valdez oil spill, scattered patches of subsurface oil residues (SSOR) can still be found in intertidal sediments at a small number of shoreline locations in Prince William Sound, Alaska. Some scientists hypothesize that sea otters continue to be exposed to SSOR by direct contact when otters dig pits in search of clams. This hypothesis is examined through site-specific examinations where SSOR and otter-dug pits co-occur. Surveys documented the exact sediment characteristics and locations on the shore at the only three subdivisions where both SSOR and otter pits were found after 2000. Shoreline characteristics and tidal heights where SSOR have persisted are not suitable habitat for sea otters to dig pits during foraging. There is clear separation between areas containing SSOR and otter foraging pits. The evidence allows us to reject the hypothesis that sea otters encounter and are being exposed by direct contact to SSOR.  相似文献   
123.
The concentrations of ten trace metals were determined in the gills, muscles, hepatopancreas, and exoskeleton tissues of Xenograpsus testudinatus that lives around shallow and acidic hydrothermal vents off Kueishan Island, northeastern Taiwan. The analytical results demonstrate that the metal concentrations vary significantly with the type of crab tissue. The concentrations of Al, Cd, Co, Cu, Fe, Ni, and Zn are highest in the gills, whereas the concentration of Mn is highest in the exoskeleton. Cr and Pb concentrations are similar across the different tissues. The enhanced accumulation of most metals in the gills suggests the metal accumulation via the respiration pathway rather than the uptake of food. The results also reveal that the distribution patterns of metals in tissues are similar in the hepatopancreas and muscles, but very different in both the gills and the exoskeleton, perhaps because of the different pathways of metal utilization in the different crab tissues.  相似文献   
124.
自动站实时数据质量分析及质控算法改进   总被引:1,自引:0,他引:1  
自动气象站实时资料对于气象预警、决策服务、预报验证等方面具有重要意义,为确保自动站实时资料的科学性和准确性,开展实时资料质量控制工作十分必要。对综合气象观测系统运行监控平台中国家级自动气象站2013年的数据质量情况进行了统计和分析,并基于自动站历史数据研究了特殊天气事件发生时气象要素的变化规律以及要素之间的内部一致性,提出了高湿事件和单站天气突变事件的判断条件以改进自动站质量控制算法,最后给出了新算法的应用情况,结果表明改进后的质控算法有效地降低了数据误判率,取得了较好的控制效果。  相似文献   
125.
In recent years, there has been a decline in the wild populations of river pufferfish, Takifugu obscurus. Besides overexploitation for commercial purposes, environmental pollution is believed to have contributed to its decline. However, almost no information exists about genes involved in metabolism of xenobiotics by this species. Nevertheless, there is interest in fugu fishes, since they possess the smallest genome among vertebrates. We cloned and characterized the full-length cDNA sequence of a cytochrome P450 1A (CYP1A) gene from T. obscurus. Phylogenic relationship of T. obscurus CYP1A was also compared to other fish species. The tissue distribution and time-dependant induction of CYP1A mRNA were studied by real-time PCR in T. obscurus exposed to an aryl hydrocarbon receptor (Ahr) agonist, beta-naphthoflavone (BNF). The greatest basal expression in livers of control as well as BNF-treated individuals. However, brain, gill, gonad, intestine, and kidney also expressed CYP1A. Muscles expressed the least CYP1A. The results of the time-course study revealed induction in brain and gills after 6h and at 12h in most tissues. Except for gills, all other organs retained induced expression of CYP1A mRNA up to 96h.  相似文献   
126.
This study examined the effects of anthropogenic contaminants and environmental variables on the composition of benthic diatom communities within a contaminated bay adjacent to an abandoned waste disposal site in Antarctica. The combination of geographical, environmental and chemical data included in the study explained all of the variation observed within the diatom communities. The chemical data, particularly metal concentrations, explained 45.9% of variation in the diatom communities, once the effects of grain-size and spatial structure had been excluded. Of the metals, tin explained the greatest proportion of variation in the diatom communities (28%). Tin was very highly correlated (R2>0.95) with several other variables (copper, iron, lead, and sum of metals), all of which explained similarly high proportions of total variation. Grain-size data explained 23% of variation once the effects of spatial structure and the chemical data had been excluded. The pure spatial component explained only 1.8% of the total variance. The study demonstrates that much of the compositional variability observed in the bay can be explained by concentrations of metal contaminants.  相似文献   
127.
In order to assess its potential as a biomarker of aquatic pollution, an alpha class glutathione S-transferase gene (GSTalpha gene) was cloned from the small hermaphroditic fish Rivulus marmoratus. The R. marmoratus GSTalpha gene spanned 1.3 kb, consisting of 6 exons encoding 221 amino acid residues. It showed high similarity to zebrafish GST. We named this R. marmoratus GSTalpha gene as rm-GSTalpha. The cDNA of the rm-GSTalpha gene was also investigated for its phylogeny, tissue-specific and chemical-induced expression. Rm-GSTalpha was subcloned into a 6 x His-tagged pCRT7 TOPO TA expression vector to produce the recombinant 6 x His-tagged rm-GST protein. This will be used in future to raise an rm-GSTalpha antibody for use in the study of phase II metabolism involved in detoxification. We also exposed R. marmoratus to 300 microg/l of 4-nonylphenol in water, and found approximately 4-fold induction of R. marmoratus GSTalpha mRNA in the treated animals. In this paper, we discuss the characteristics of the R. marmoratus GSTalpha gene as well as its potential use in relation to environmental pollution.  相似文献   
128.
无损技术具有透视固状物体内部及其其下面性状的能力,使其在许多领域起着重要的作用,这些领域也可用有损方法进行调查,如探查混凝土、土壤或基岩时,尽管可以 采用取心或钻孔获得有关地下目标物的详细资料,但这种技术只能在试验井附近的小范围内有效。  相似文献   
129.
The structural coupling is a common geological phenomenon. The structural differences between eastern and western active continental margins of modern Pacific and between paleo-Pacific and modern-Pacific continental margins are related to the characteristics and status of the subducting oceanic plate, namely, 1. subducting angle; 2. change in subducting angle; 3. subducting velocity; 4. change in subducting velocity; 5. subduction depth; 6. horizontal distance between the leading edge of the subducting plate and the trench; 7. the structural form of the subducting plate at the 670kin boundary between the upper and lower mantle; 8. the displacement and the direction of displacement of subducting plate. The control and influence toward the shallow-level structures by the deep-level structural activities is a detailed representation of the structural coupling on active continental margin. The basin-maintain coupling phenomenon is an intracontinental structural coupling. The far field effect of collision be  相似文献   
130.
We have cloned the proto-oncogene c-fos from a self-fertilizing fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae) after screening of R. marmoratus lambdaGEM-11 genomic DNA library, and sequenced over 12 kb including all exons, introns and the promoter region. The R. marmoratus c-fos gene consisted of one noncoding exon and four exons with high similarity to those of fugu and mammals. We sequenced approximately 7 kb of the R. marmoratus c-fos gene promoter region to gain a better understanding of the molecular anatomy of the immediate response of this gene upon cellular damage. In the promoter region, R. marmoratus c-fos gene has seven xenobiotic response elements (XREs) and eight metal response elements (MREs) as well as two estradiol (E2), 4 NFkappaB, 2 CarG, 2 prolactin (PRL) motifs and one pit1 site, while the 3'-UTR of this gene contains the estrogen response element (ERE). The seven XRE and eight MRE motifs raise the possibility of its regulation by exposure to environmental pollutants. In this paper, we discuss the gene structure of R. marmoratus c-fos gene and compare its promoter region with those of other organisms' c-fos genes. We propose its potential use in ecotoxicology.  相似文献   
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