以Web of Science数据库及CNKI(中国知网)的文献资料为数据源,利用CiteSpace文献计量工具,对湖泊抗生素抗性基因的研究文献从发展路径、主题演变以及研究热点等方面进行剖析,以此探讨国内外该领域的研究现状、热点和发展态势.结果 表明,湖泊中抗生素抗性基因的研究文献发文数量和载文期刊数量呈快速增长态势;... 相似文献
CHEMTAX is a mathematical software for phytoplankton composition evaluation using pigment composition. Although this method has been previously applied in the ocean environment, we firstly utilized the combination of matrix factorization program CHEMTAX and high-performance liquid chromatography (HPLC) to characterize the phytoplankton community from a river system (western part of Weihe River Basin). The obtained results were compared with those from microscopic examination. Based on the comparison, it is suggested that after increasing the ratio of characteristic pigment to chlorophyll a of diatoms and euglena, the diatoms calculated by the CHEMTAX method accounted for 80% of the total biomass, and the results were consistent with microscopic examination, but diatoms obtained from F2, C1 and W5 sample sites were significantly overestimated 33%~60%. The comparison also showed that the model always underestimated cyanobacteria (sample sites F2, C1 were underestimated 25%) and euglena were overestimated (sample sites W3, Q1 were respectively overestimated 33%, 23%), but for chlorophytes, both overestimation and underestimation could occur. When the relevant results from previous applications in the ocean phytoplankton community evaluation were taken into consideration, it can be concluded that CHEMTAX-HPLC method was not accurate enough to characterize the phytoplankton communities in the freshwater (river/lake) ecosystem.
Environmental Science and Pollution Research - Morphological effect of bismuth vanadate (BiVO4) on visible light-driven catalytic degradation of aqueous paracetamol was carefully investigated using... 相似文献
Instrument neutron activation analysis (INAA) has been employed in this study to determine 32 elements in soil on the loess plateau. The preliminary results suggest that geochemical characteristics of elements in the soil mainly retained those in the parent materials (loess). It has been found that fractional deposition among grain sizes in the process of loess transportation as well as the bioclimate in which the soil developed are main factors affecting the regional variations of elemental distribution in soil on the plateau. Contour maps of element concentrations plotted from the trend analyses exhibit the major patterns of the distributions and variations on the plateau. Furthermore, the study also provides evidence for the aeolian theory of the loess transportation in China. 相似文献
As a new emerging environmental contaminant, perchlorate has prompted people to pay more attention. The presence of perchlorate in the human body can result in improper regulation of metabolism for adults. Furthermore, it also causes developmental and behavioral problems for infants and children because it can interfere with iodide uptake into the thyroid tissue. In this paper, perchlorate in sewage sludge, rice, bottled drinking water and milk was detected for investigating the perchlorate pollution status in China. The places, where the samples were collected, cover most regions of China. Therefore, the final data on perchlorate levels will give an indication of the perchlorate pollution status in China. The final determination of perchlorate was performed by ion chromatography-electrospray tandem mass spectrometry with negative mode. The concentration of perchlorate in sewage sludge, rice, bottled drinking water and milk was in the range of 0.56-379.9 microg/kg, 0.16-4.88 mug/kg, 0.037-2.013 microg/L and 0.30-9.1 microg/L, respectively. The results show that perchlorate has been widespread in China. 相似文献