A new kind of phenyl-functionalized magnetic fibrous mesoporous silica(Fe3 O4@Si O2@KCC-1-phenyl) was prepared by copolymerization as an efficient adsorbent for the magnetic extraction of phthalate esters from environ...A new kind of phenyl-functionalized magnetic fibrous mesoporous silica(Fe3 O4@Si O2@KCC-1-phenyl) was prepared by copolymerization as an efficient adsorbent for the magnetic extraction of phthalate esters from environmental water samples. The obtained Fe3 O4@Si O2@KCC-1-phenyl showed monodisperse fibrous spherical morphology, fairly strong magnetic response(29 emu/g), and an abundant π-electron system, which allowed rapid isolation of the Fe3 O4@Si O2@KCC-1-phenyl from solutions upon applying an appropriate magnetic field. Several variables that affect the extraction efficiency of the analytes,including the type of the elution solvent, amount of adsorbent, extraction time and reusability, were investigated and optimized. Under optimum conditions, the Fe3 O4@Si O2@KCC-1-phenyl was used for the extraction of four phthalate esters from environmental water samples followed by high-performance liquid chromatographic analysis. Validation experiments indicated that the developed method presented good linearity(0.1-20 ng/m L), low limit of detection(7.5-29 μg/L, S/N =3). The proposed method was applied to the determination of phthalate esters in different real water samples, with relative recoveries of 93%-103.4%and relative standard deviation of 0.8%-8.3%.展开更多
It is claimed that open spaces in cities, such as parks, have an urban cooling effect. However, the relationship between urban parks and adjacent districts is still not explicit. In order to clarify the interaction be...It is claimed that open spaces in cities, such as parks, have an urban cooling effect. However, the relationship between urban parks and adjacent districts is still not explicit. In order to clarify the interaction between urban parks and their urban surroundings, this paper takes the Temple of Heaven Park （THP） as an example of a park station and focuses on analyzing the differences with a nearby urban station.THP is located in the center of Beijing, and the nearest urban station is Tian An Men. It is interesting that the cooling effect of THP reaches a peak and remains stable when its city background urban heat island （UHI） varies within a given range, but becomes unstable when the UHI goes beyond the range. This is called an enhanced cooling effect in this paper. As a result, the UHi intensities （UHIIs） are calculated in order to comprehend the role of the park cooling effect in the urban heating characteristics of Beijing. By comparison with five other park-district pairs, this paper attempts to identify the causes of the enhanced cooling effect. It is found that six park-district pairs consistently demonstrate a persistently stronger cooling rate during the night, and that the water coverage might be a key factor in enhancing the park cooling effect. Based on further investigation of the influence of surrounding UHIs on the park cooling effect, it is found that the UHII differences in park-district pairs show quasi-linear changes within a given range as the UHli of the surrounding district increases.展开更多
基金supported by the Commonwealth Scientific Foundation for Industry of Chinese Inspection and Quarantine (No.201210071) of the Ministry of National Science and Technology of ChinaChongqing Key Laboratory of Scientific Utilization of Tobacco Resources
文摘A new kind of phenyl-functionalized magnetic fibrous mesoporous silica(Fe3 O4@Si O2@KCC-1-phenyl) was prepared by copolymerization as an efficient adsorbent for the magnetic extraction of phthalate esters from environmental water samples. The obtained Fe3 O4@Si O2@KCC-1-phenyl showed monodisperse fibrous spherical morphology, fairly strong magnetic response(29 emu/g), and an abundant π-electron system, which allowed rapid isolation of the Fe3 O4@Si O2@KCC-1-phenyl from solutions upon applying an appropriate magnetic field. Several variables that affect the extraction efficiency of the analytes,including the type of the elution solvent, amount of adsorbent, extraction time and reusability, were investigated and optimized. Under optimum conditions, the Fe3 O4@Si O2@KCC-1-phenyl was used for the extraction of four phthalate esters from environmental water samples followed by high-performance liquid chromatographic analysis. Validation experiments indicated that the developed method presented good linearity(0.1-20 ng/m L), low limit of detection(7.5-29 μg/L, S/N =3). The proposed method was applied to the determination of phthalate esters in different real water samples, with relative recoveries of 93%-103.4%and relative standard deviation of 0.8%-8.3%.
基金supported by the National Natural Science Foundation of China[grant number 41375069]National Basic Research Program of China[grant number 2012CB957804]Young Talent Programming of China Meteorological Administration
文摘It is claimed that open spaces in cities, such as parks, have an urban cooling effect. However, the relationship between urban parks and adjacent districts is still not explicit. In order to clarify the interaction between urban parks and their urban surroundings, this paper takes the Temple of Heaven Park （THP） as an example of a park station and focuses on analyzing the differences with a nearby urban station.THP is located in the center of Beijing, and the nearest urban station is Tian An Men. It is interesting that the cooling effect of THP reaches a peak and remains stable when its city background urban heat island （UHI） varies within a given range, but becomes unstable when the UHI goes beyond the range. This is called an enhanced cooling effect in this paper. As a result, the UHi intensities （UHIIs） are calculated in order to comprehend the role of the park cooling effect in the urban heating characteristics of Beijing. By comparison with five other park-district pairs, this paper attempts to identify the causes of the enhanced cooling effect. It is found that six park-district pairs consistently demonstrate a persistently stronger cooling rate during the night, and that the water coverage might be a key factor in enhancing the park cooling effect. Based on further investigation of the influence of surrounding UHIs on the park cooling effect, it is found that the UHII differences in park-district pairs show quasi-linear changes within a given range as the UHli of the surrounding district increases.
