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1.
Huan Jing Ke Xue ; 40(10): 4497-4504, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854817

RESUMO

To clarify the spatial distribution and pollution status of nutrients in the surface sediments from a macrophyte-dominated zone in Lake Taihu, total nitrogen (TN), total phosphorus (TP), alkali nitrogen (AN), available phosphorus (AP), and organic matter (OM) were measured at 60 sampling sites in Xukou Bay. A pollution evaluation and source apportionment analysis of these nutrients was also carried out. The average contents of TN, TP, AN, AP, and OM in the surface sediments of Xukou Bay were 1027.5, 423.2, 46.4, 15.3, and 17096.6 mg·kg-1, respectively, with the OM content being significantly higher in the northeast zone than in other areas of the bay. The average value of STN and STP was 1.75 and 0.91, respectively, indicating that TN and TP represent moderate and mild levels of pollution, respectively. The average comprehensive pollution index (FF) was 1.57, indicated that the surface sediment was moderately polluted. The observed organic pollution index indicated that the surface sediments in Xukou Bay were generally clean. Based on C/N values, organic matter in the surface sediments is derived from the bio-deposition of non-fibrous plants and phytoplankton. Based on correlation analysis, OM and TN in the surface sediments of Xukou Bay are derived from the same source, while TP is derived from an alternative source.


Assuntos
Lagos , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos , Nitrogênio , Nutrientes , Fósforo
2.
Atten Percept Psychophys ; 81(8): 2814-2831, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31165451

RESUMO

Previous studies have produced contradictory findings regarding whether emotion exerts facilitative effects or inhibitory effects on perception. In the present study, we hypothesized that attention can be separated into the initial selection stage and the latter consolidation stage, and emotion plays a different role in each of these two stages. To test this hypothesis, we adopted the dual-stream rapid serial visual presentation paradigm (Goodbourn & Holcombe, Journal of Experimental Psychology: Human Perception and Performance, 41(2), 364-384, 2015), which provided separate measurements for selection latency (how delayed the attentional selection process is) and efficacy (how much information can be successfully consolidated for conscious report). The results suggested emotion's dual role on perception. Firstly, the presence of negatively charged visual targets (which were Chinese characters in the present study) accelerated attention selection, and the acceleration effect could spread to different locations in the visual field. Secondly, negatively charged characters preoccupied attentional resources for consolidation, yielding location-specific facilitative and inhibitory effects.

3.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(3): 551-4, 2008 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-18536410

RESUMO

Hydrogen bondings in polyurethane urea elastomer, which reflect the microphase separation, have an important effect on the properties of the elastomer. The polyurethane urea elastomers, whose degree of microphase separation changed gradually, were prepared in the graded temperature field. Hydrogen bondings in them were investigated by FTIR technology. The discussions about C=O, NH, and -O- stretching vibration spectra were given. The percentage of hydrogen bonded carbonyl groups increases with the increase in the curing temperature in the thickness direction, which indicates the increase in the degree of microphase separation in it. The degree of hydrogen bonded ether oxygen atoms exhibits obvious difference in polyurethane urea with different crosslinking degree. It is this difference that leads to a contrast changing trend of the percentage of hydrogen bonded NH in different samples. Three-dimensional hydrogen bonding between urea carbonyl and NH is stronger than the hydrogen bonding between ether oxygen atoms and NH. The stretching vibration of hydrogen bonded ether group is at about 1 076 cm(-1).

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