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排序方式: 共有117条查询结果,搜索用时 31 毫秒
91.
Yuichi Miyake Qinting Jiang Wang Yuan Nobuyasu Hanari Tsuyoshi Okazawa Barbara Wyrzykowska Man Ka So Paul K.S. Lam Nobuyoshi Yamashita 《Marine pollution bulletin》2008,57(6-12):357
Dietary intake is one of the important routes of human exposure to brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs). The use of PBDEs may also result in exposure to polybrominated dibenzo-p-dioxins and dibenzofurans (PBDDs/DFs), as these compounds are impurities in technical mixtures of BFRs and can also be formed unintentionally by the same processes that generate chlorinated dioxins. This study determined the concentrations of polybrominated compounds in common seafood in Guangzhou and Zhoushan, and assessed the health risks of these chemicals via consumption of contaminated seafood. Seafood samples (fish, bivalves, shrimp, crab, and cephalopods) purchased from local markets in 2003 and 2004 were analyzed for PBDEs and PBDDs/DFs. The highest concentration of total PBDEs (46.3 ng g−1 lipid wt.) was detected in fish from Guangzhou, in which BDEs 47 and 209 were the two predominant congeners. The total daily intakes of PBDEs, PBDDs, and PBDFs were, 946, 6.39, and 6.54 pg kg−1 body weight (bw) in Guangzhou, and 489, 4.99, and 7.65 pg kg−1 bw in Zhoushan, respectively. The hazard ratios for PBDDs and PBDFs were both greater than unity, indicating that these compounds may pose some health risks to the local population. 相似文献
92.
PARK Mirye PARK So Yun HWANG Jinik JUNG Seung Won LEE Juyun CHANG Man LEE Taek-Kyun 《海洋学报(英文版)》2018,37(5):107-112
Microalgae are photosynthetic microorganisms that function as primary producers in aquatic ecosystems. Some species of microalgae undergo rapid growth and cause harmful blooms in marine ecosystems. Heterocapsa triquetra is one of the most common bloom-forming species in estuarine and coastal waters worldwide. Although this species does not produce toxins, unlike some other Heterocapsa species, the high density of its blooms can cause significant ecological damage. We developed a H. triquetra species-specific nuclease protection assay sandwich hybridization (NPA-SH) probe that targets the large subunit of ribosomal RNA (LSU rRNA). We tested probe specificity and sensitivity with five other dinoflagellates that also cause red tides. Our assay detected H. triquetra at a concentration of 1.5×104 cells/mL, more sensitive than required for a red-tide guidance warning by the Korea Ministry of Oceans and Fisheries in 2015 (3.0×104 cells/mL). We also used the NPA-SH assay to monitor H. triquetra in the Tongyeong region of the southern sea area of Korea during 2014. This method could detect H. triquetra cells within 3 h. Our assay is useful for monitoring H. triquetra under field conditions. 相似文献
93.
对多震相走时层析成像方法进行改进和优化, 使用朝鲜半岛陆地和近海的地震记录, 对朝鲜半岛南部(345°N~39°N,125°E~130°E)进行地震波走时反演, 获得了本研究区的三维速度结构成像结果.分析了沉积层、基底、上地壳、康腊面、下地壳和莫霍面的特征.研究了不同地质区的深部结构的主要差别、主要断裂特征、 海陆交界的地壳特征等.可以发现京畿山地与沃川褶皱带、太白山褶皱带、临津江褶皱带深部结构的差异尤为明显. 相似文献
94.
This research is supported by the Research Grants Council of the University Grants Committee of Hong Kong Grant . C. H. So Johnny C. L. Chan Department of Physics Materials Science City University of Hong Kong 《大气科学进展》1997,(2)
RegionalandSynoptic-scaleFeaturesAsociatedwithInactivePeriodsoftheSummerMonsoonoverSouthChina①C.H.SoandJohnnyC.L.ChanDepartme... 相似文献
95.
Gulkowska A He Y So MK Yeung LW Leung HW Giesy JP Lam PK Martin M Richardson BJ 《Marine pollution bulletin》2007,54(8):1287-1293
96.
In order to evaluate the use of satellite (moderate resolution imaging spectroradiometer: MODIS) and ground-measured (hyperspectral spectrometer and broadband micrometeorological sensors) normalized difference vegetation index (NDVI), this study compares NDVI derived from five experimental (FLUXNET) field sites (grassland, winter wheat, corn, spruce, and beech) in Germany in June 2006 and April-September 2007. In addition, the spatial variability of ground radiation measured within one specific land-use class (for grass and winter wheat) was investigated to analyze the accuracy of the FLUXNET tower values. Furthermore, the angular dependence of spectrometer values on viewing angles was determined in order to enhance the spatial representativeness of spectrometer measurements which, especially above trees, are affected by soil parts and the tower structure when measured in nadir. The best agreement between the satellite- and ground-measured NDVI was found for winter wheat (2006) with values from 0.79–0.88 followed by grass (2006), showing NDVI values between 0.71 and 0.86. The spatial variability of NDVI within one land-use type was lower than the differences caused by the different NDVI determination methods. Above more open canopies (corn, beech), spectrometer measurements with 60° viewing angle in solar plane direction were found to better correspond to satellite-derived NDVI. Together with broadband NDVI, our ground-based results can complement satellite-derived NDVI. 相似文献
97.
98.
Yong-Kwon Koh Seon-Gyu Choi Chil-Sup So Sang-Hoon Choi Etsuo Uchida 《Mineralium Deposita》1992,27(1):58-65
The Taebaek Pb-Zn(-Ag) deposit of the Yeonhwa I mine, Republic of Korea, occurs in a broadly folded and reverse-faulted terrain of Paleozoic sedimentary rocks: the Taebaeksan basin. The orebodies consist of several thin tabular orebodies of hydrothermal replacement type where they are hosted by carbonate rocks. The Pb-Zn(-Ag) mineralization can be divided into four distinct stages based upon the mode of occurrence of ore minerals, ore textural relationships and their composition. Based on temperatures inferred from arsenopyrite compositions by means of electron microprobe and fluid inclusions, the estimated temperatures for the stages I, II, III and IV reach 330 to 350 °C, 270 to 340 °C, 230 to 250 °C, and <220 °C, respectively. The sulphur activity (atm) of ore formation at the Taebaek deposit was estimated for each stage as 10–11 to 10–11.5, 10–9.5 to 10–13, 10–13.5 to 10–15, and <10–15, respectively. Even though application of sphalerite geobarometry is problematic because of the absence of good mineral assemblages, sphalerite coexisting with pyrite but not with pyrrhotite was used to estimate the minimum mineralization pressure (about 1 kbar). 相似文献
99.
100.
David Kirkman † David Tytler † Nao Suzuki † Carl Melis Susan Hollywood Kory James Geoffrey So Dan Lubin † Tridivesh Jena Michael L. Norman Pascal Paschos 《Monthly notices of the Royal Astronomical Society》2005,360(4):1373-1380
We use high-quality echelle spectra of 24 quasi-stellar objects to provide a calibrated measurement of the total amount of Lyα forest absorption (DA) over the redshift range 2.2 < z < 3.2 . Our measurement of DA excludes absorption from metal lines or the Lyα lines of Lyman-limit systems and damped Lyα systems. We use artificial spectra with realistic flux calibration errors to show that we are able to place continuum levels that are accurate to better than 1 per cent. When we combine our results with our previous results between 1.6 < z < 2.2 , we find that the redshift evolution of DA is well described over 1.6 < z < 3.2 as A (1 + z )γ , where A = 0.0062 and γ= 2.75 . We detect no significant deviations from a smooth power-law evolution over the redshift range studied. We find less H i absorption than expected at z = 3 , implying that the ultraviolet background is ∼40 per cent higher than expected. Our data appears to be consistent with an H i ionization rate of Γ∼ 1.4 × 10−12 s−1 . 相似文献