Fifty-one tree leaves were sampled in the industrial area,residential area,and Fenhe River ecological zone,for the purpose of a magnetic study on atmospheric pollution in Linfen City,Shanxi Province,China.Measurements...Fifty-one tree leaves were sampled in the industrial area,residential area,and Fenhe River ecological zone,for the purpose of a magnetic study on atmospheric pollution in Linfen City,Shanxi Province,China.Measurements of mass-specific magnetic susceptibility(χ) show a significant variation range(from 11.6 × 10-8 m3/kg to 129.7 × 10-8 m3/kg).Overall values of magnetic susceptibility decline in the following sequence:industrial area > residential area > Fenhe River ecological zone.The relatively elevated concentration-related magnetic parameters(saturation isothermal remanent magnetization,anhysteretic remanent magnetization and magnetic susceptibility) appear in the industrial area,with their highest values in the vicinity of Linfen Steel Mill.Magnetic particles are dominated by multidomain,magnetite-like minerals.Magnetic particle concentration and grain size both decrease with the increasing distance from industrial area,indicating the industrial area,especially Linfen Steel Mill,is the main source of atmospheric particle pollution.Residential area and Fenhe River ecological zone are also affected by industrial emission to a certain extent.The results of this study indicate that magnetic measurements of tree leaves are practicable for monitoring and determination of atmospheric pollution in Linfen City.展开更多
The study of tree leaf aerodynamics is useful to tree protection, solar panel design and development of new power generation technology. 73 tulip leaves were tested in suspended condition and with front as well as bac...The study of tree leaf aerodynamics is useful to tree protection, solar panel design and development of new power generation technology. 73 tulip leaves were tested in suspended condition and with front as well as back surface of the lamina facing wind. Three types of vibrating statuses, two types of steady statuses, and five critical wind speeds were observed. The existence probabilities of the statuses and criticals, the probability density distribution of every critical over the range of wind speed 0-27 m/s, and the expected values of the criticals were obtained by statistics. The critical Reynolds number, defined by critical wind speed and lamina length, shows an increasing trend with increasing the lamina area or length to width ratio of the lamina, but it shows no trend of increase or decrease with increasing the length ratio of petiole to lamina.展开更多
The present work deals with the removal of Ni（II） ion using activated charcoal prepared from the dry leaves of bitter orange tree （Citrus aurantium）. The effects of its concentration, adsorbent dosage, particle si...The present work deals with the removal of Ni（II） ion using activated charcoal prepared from the dry leaves of bitter orange tree （Citrus aurantium）. The effects of its concentration, adsorbent dosage, particle size, pH and temperature on removal of Ni（II） ion have been studied. The removal of Ni（II） ion is higher at lower concentration and gradually decreases as the concentration increases. The pH of 5 was the most suitable. The removal of Ni（II） ion increases with the increases in the adsorbent dosage. The effect of particle size reveals that the percentage removal of Ni（II） ion decreases with increase in particle size of adsorbent. The effect of temperature shows that as temperature increases, the percentage removal of Ni（II） ion decreases and this is due to the interaction forces weakening at high temperature. Thermodynamic parameters from the effect of temperature were calculated.展开更多
Radiocarbon content in biogenic samples is widely used to study the variation of atmospheric CO<sub>2</sub> due to anthropogenic activities. A total of 20 samples of several types of tree leaves, were anal...Radiocarbon content in biogenic samples is widely used to study the variation of atmospheric CO<sub>2</sub> due to anthropogenic activities. A total of 20 samples of several types of tree leaves, were analyzed for this study. Sampling was carried out at the end of the rainy season in 2017 from the surrounding of the SOCOCIM cement factory in Rufisque town. Rufisque is located on the peninsula of Cape Verde, 25 km east of Dakar, where it is the 《south gate》 of the agglomeration. Reference samples of five different species were collected during the same period (2017) from a clean zone. The <sup>14</sup>C method was used for the determination of Δ<sup>14</sup>C values. The data show that the <sup>14</sup>C concentration in the studied sites was significantly lower than the clean area, due to the release of anthropogenic CO<sub>2</sub>. To estimate the Suess effect, the fossil fuel fraction was determined based on equations of mass balance for CO<sub>2</sub> concentration, stable isotopic composition of carbon, and <sup>14</sup>C concentration. The results show that selected locations are affected differently according to their distance from the factory and the wind direction.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 40972216)Deutsche Forschungsgemein-schaft (DFG) Project (NO. AP 34/21)
文摘Fifty-one tree leaves were sampled in the industrial area,residential area,and Fenhe River ecological zone,for the purpose of a magnetic study on atmospheric pollution in Linfen City,Shanxi Province,China.Measurements of mass-specific magnetic susceptibility(χ) show a significant variation range(from 11.6 × 10-8 m3/kg to 129.7 × 10-8 m3/kg).Overall values of magnetic susceptibility decline in the following sequence:industrial area > residential area > Fenhe River ecological zone.The relatively elevated concentration-related magnetic parameters(saturation isothermal remanent magnetization,anhysteretic remanent magnetization and magnetic susceptibility) appear in the industrial area,with their highest values in the vicinity of Linfen Steel Mill.Magnetic particles are dominated by multidomain,magnetite-like minerals.Magnetic particle concentration and grain size both decrease with the increasing distance from industrial area,indicating the industrial area,especially Linfen Steel Mill,is the main source of atmospheric particle pollution.Residential area and Fenhe River ecological zone are also affected by industrial emission to a certain extent.The results of this study indicate that magnetic measurements of tree leaves are practicable for monitoring and determination of atmospheric pollution in Linfen City.
基金financially supported by the National Natural Science Foundation of China(11172286)
文摘The study of tree leaf aerodynamics is useful to tree protection, solar panel design and development of new power generation technology. 73 tulip leaves were tested in suspended condition and with front as well as back surface of the lamina facing wind. Three types of vibrating statuses, two types of steady statuses, and five critical wind speeds were observed. The existence probabilities of the statuses and criticals, the probability density distribution of every critical over the range of wind speed 0-27 m/s, and the expected values of the criticals were obtained by statistics. The critical Reynolds number, defined by critical wind speed and lamina length, shows an increasing trend with increasing the lamina area or length to width ratio of the lamina, but it shows no trend of increase or decrease with increasing the length ratio of petiole to lamina.
文摘The present work deals with the removal of Ni（II） ion using activated charcoal prepared from the dry leaves of bitter orange tree （Citrus aurantium）. The effects of its concentration, adsorbent dosage, particle size, pH and temperature on removal of Ni（II） ion have been studied. The removal of Ni（II） ion is higher at lower concentration and gradually decreases as the concentration increases. The pH of 5 was the most suitable. The removal of Ni（II） ion increases with the increases in the adsorbent dosage. The effect of particle size reveals that the percentage removal of Ni（II） ion decreases with increase in particle size of adsorbent. The effect of temperature shows that as temperature increases, the percentage removal of Ni（II） ion decreases and this is due to the interaction forces weakening at high temperature. Thermodynamic parameters from the effect of temperature were calculated.
文摘Radiocarbon content in biogenic samples is widely used to study the variation of atmospheric CO<sub>2</sub> due to anthropogenic activities. A total of 20 samples of several types of tree leaves, were analyzed for this study. Sampling was carried out at the end of the rainy season in 2017 from the surrounding of the SOCOCIM cement factory in Rufisque town. Rufisque is located on the peninsula of Cape Verde, 25 km east of Dakar, where it is the 《south gate》 of the agglomeration. Reference samples of five different species were collected during the same period (2017) from a clean zone. The <sup>14</sup>C method was used for the determination of Δ<sup>14</sup>C values. The data show that the <sup>14</sup>C concentration in the studied sites was significantly lower than the clean area, due to the release of anthropogenic CO<sub>2</sub>. To estimate the Suess effect, the fossil fuel fraction was determined based on equations of mass balance for CO<sub>2</sub> concentration, stable isotopic composition of carbon, and <sup>14</sup>C concentration. The results show that selected locations are affected differently according to their distance from the factory and the wind direction.
