A green and convenient pathway of preparing iron nanoparticles(FeNPs)with pomegranate leaf(PG)extract for highly effective removal of malachite green(MG)was proposed under ambient conditions.The materials were charact...A green and convenient pathway of preparing iron nanoparticles(FeNPs)with pomegranate leaf(PG)extract for highly effective removal of malachite green(MG)was proposed under ambient conditions.The materials were characterized by scanning electron microscope(SEM),X-ray energy-dispersive spectrometer(EDS),Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)techniques.The results show that their surfaces are capped and stabilized by PG extract with amorphous nature and without any detection of zero-valent iron.The size and surface valence state of FeNPs are the key factors that affect the MG removal efficiency.As the reagent volume ratio of PG extract to FeCl_(3) increases greater than 1,the cross-linked FeNPs become more obvious,having a homogeneous distribution with the size range from 30 to 40 nm,and show an increasing ratio ofFe(Ⅱ)/Fe(Ⅲ),which is in proportion to the degradation efficiency of MG,reaching higher than 95%in only 2 min by using 50 mg Fe/L FeNPs and 200 mg/L MG.展开更多
The Tibetan Plateau, with an average altitude above 4000 m, is the highest and largest plateau in the world. The frequency of thunderstorms in this region is extremely high. Many indices are used in operational foreca...The Tibetan Plateau, with an average altitude above 4000 m, is the highest and largest plateau in the world. The frequency of thunderstorms in this region is extremely high. Many indices are used in operational forecasting to assess the stability of the atmosphere and predict the probability of severe thunderstorm development. One of the disadvantages of many of these indices is that they are mainly based on observations from plains. However, considering the Plateau＇s high elevation, most convective parameters cannot be applied directly, or their application is ineffective. The pre-convective environment on thunderstorm days in this region is investigated based on sounding data obtained throughout a five-year period（2006–10）.Thunderstorms occur over the Tibetan Plateau under conditions that differ strikingly from those in plains. On this basis,stability indices, such as the Showalter index（including SI and SICCL）, and the K index are improved to better assess the thunderstorm environments on the Plateau. Verification parameters, such as the true-skill statistic（TSS） and Heidke skill score（HSS）, are adopted to evaluate the optimal thresholds and relative forecast skill for each modified index. Lastly, the modified indices are verified with a two-year independent dataset（2011–12）, showing satisfactory results for the modified indices. For determining whether or not a thunderstorm day is likely to occur, we recommend the modified SICCLindex.展开更多
基金the National Natural Science Foundation of China(No.21407050)the Excellent Young and Middle-aged Science and Technology Innovation Team Plan of Hubei Colleges(No.T201824)。
文摘A green and convenient pathway of preparing iron nanoparticles(FeNPs)with pomegranate leaf(PG)extract for highly effective removal of malachite green(MG)was proposed under ambient conditions.The materials were characterized by scanning electron microscope(SEM),X-ray energy-dispersive spectrometer(EDS),Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)techniques.The results show that their surfaces are capped and stabilized by PG extract with amorphous nature and without any detection of zero-valent iron.The size and surface valence state of FeNPs are the key factors that affect the MG removal efficiency.As the reagent volume ratio of PG extract to FeCl_(3) increases greater than 1,the cross-linked FeNPs become more obvious,having a homogeneous distribution with the size range from 30 to 40 nm,and show an increasing ratio ofFe(Ⅱ)/Fe(Ⅲ),which is in proportion to the degradation efficiency of MG,reaching higher than 95%in only 2 min by using 50 mg Fe/L FeNPs and 200 mg/L MG.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41275128, 41375063 and 41206163)the Chengdu Institute of Plateau Meteorology Foundation
文摘The Tibetan Plateau, with an average altitude above 4000 m, is the highest and largest plateau in the world. The frequency of thunderstorms in this region is extremely high. Many indices are used in operational forecasting to assess the stability of the atmosphere and predict the probability of severe thunderstorm development. One of the disadvantages of many of these indices is that they are mainly based on observations from plains. However, considering the Plateau＇s high elevation, most convective parameters cannot be applied directly, or their application is ineffective. The pre-convective environment on thunderstorm days in this region is investigated based on sounding data obtained throughout a five-year period（2006–10）.Thunderstorms occur over the Tibetan Plateau under conditions that differ strikingly from those in plains. On this basis,stability indices, such as the Showalter index（including SI and SICCL）, and the K index are improved to better assess the thunderstorm environments on the Plateau. Verification parameters, such as the true-skill statistic（TSS） and Heidke skill score（HSS）, are adopted to evaluate the optimal thresholds and relative forecast skill for each modified index. Lastly, the modified indices are verified with a two-year independent dataset（2011–12）, showing satisfactory results for the modified indices. For determining whether or not a thunderstorm day is likely to occur, we recommend the modified SICCLindex.
