Lack of public forestry information and techniques has restricted the development of forestry management and the income increase of rural farmers in hot region of Yunnan province. Therefore it is necessary to provide ...Lack of public forestry information and techniques has restricted the development of forestry management and the income increase of rural farmers in hot region of Yunnan province. Therefore it is necessary to provide forestry information and techniques to rural areas so as to compensate for the information gap between urban and rural areas. Based on the survey about farmer demand for information and technique in Menglian County,the paper analyzed the supply methods and demand characteristics of forestry information and techniques. The results showed that the farmers had very strong demands for forestry information and techniques with diversified trend. But the farmers got the information with backward method and single service supply approach,and it lacked effective expression mechanism for their demands.展开更多
The selective oxidation of methane under mild conditions remains the“Holy Grail of Catalysis”.The key to activating methane and inhibiting over-oxidation of target oxygenates lies in designing active centers.Copper ...The selective oxidation of methane under mild conditions remains the“Holy Grail of Catalysis”.The key to activating methane and inhibiting over-oxidation of target oxygenates lies in designing active centers.Copper nanoparticles were loaded onto TiO_(2) nanofibers using the photo-deposition method.The resulting catalysts were found to effectively convert methane into C1 oxygenated products under mild conditions.Compared with previously reported catalysts,it delivers a superior performance of up to 2510.7 mmol·g_(Cu)^(-1)·h^(-1) productivity with a selectivity of around 100%at 80℃for 5 min.Microstructure characterizations and density functional theory(DFT)calculations indicate that TiO_(2) in the mixed phase of anatase and rutile significantly increases the Cu^(+)/CuO ratio of the supported Cu species,and this ratio is linearly related to the formation rate of oxygen-containing species.The CuI site promotes the generation of active O species from H_(2)O_(2) dissociation on Cu_(2)O(111).These active O species reduce the energy barrier for breaking the C-H bond of CH_(4),thus boosting the catalytic activity.The methane conversion mechanism was proposed as a methyl radical pathway to form CH_(3)OH and CH_(3)OOH,and then the generated CH_(3)OH is further oxidized to HOCH_(2)OOH.展开更多
Solar photocatalysis,as a method of green energy production and sustainable technology,has been regarded as one of the most effective strategies to resolve environmental issues and the current energy crisis.In this wo...Solar photocatalysis,as a method of green energy production and sustainable technology,has been regarded as one of the most effective strategies to resolve environmental issues and the current energy crisis.In this work,intimate contact hollow Ni_(x)Co_(1-x)S polyhedron/g-C3N4 nanosheet composites were prepared in-situ through a facile one-step hydrothermal method.The as-prepared Ni_(x)Co_(1-x)S/g-C_(3)N_(4) composites showed superior photocatalytic activity and high stability for H2 generation and methyl orange(MO)degradation under visible light irradiation.The optimized 4 wt.%Ni_(x)Co_(1-x)S/g-C_(3)N_(4) composite attained a maximum H2 evolution rate of 1420μmol g^–1 h^–1,which was about 157 times higher than that of pure g-C3N4.In addition,the Ni_(x)Co_(1-x)S/g-C_(3)N_(4) composite also exhibited greatly improved photocatalytic activity for dye degradation,which for MO was at 98.14%in 9 min.The outstanding photocatalytic performance was predominantly attributed to the unique architecture of hollow Ni_(x)Co_(1-x)S polyhedrons,which not only provided more active sites at the edges and surface as convenient charge transfer channels,but also promoted the separation and transport of electron-hole pairs.This work provides some novel ideas for the design and development of highly efficient noble metal-free cocatalyst/semiconductor systems for photocatalytic H2 generation and dye degradation.展开更多
基金Supported by Fund Project of International Tropical Timber Organization(ITTO)[(P)501/08 Rev.1(F)]
文摘Lack of public forestry information and techniques has restricted the development of forestry management and the income increase of rural farmers in hot region of Yunnan province. Therefore it is necessary to provide forestry information and techniques to rural areas so as to compensate for the information gap between urban and rural areas. Based on the survey about farmer demand for information and technique in Menglian County,the paper analyzed the supply methods and demand characteristics of forestry information and techniques. The results showed that the farmers had very strong demands for forestry information and techniques with diversified trend. But the farmers got the information with backward method and single service supply approach,and it lacked effective expression mechanism for their demands.
基金supported by the National Natural Science Foundation of China(Nos.92145301,91845201,22002094,22102106,22309061)the Natural Science Foundation of Jilin Province(No.YDZJ202201ZYTS360).
文摘The selective oxidation of methane under mild conditions remains the“Holy Grail of Catalysis”.The key to activating methane and inhibiting over-oxidation of target oxygenates lies in designing active centers.Copper nanoparticles were loaded onto TiO_(2) nanofibers using the photo-deposition method.The resulting catalysts were found to effectively convert methane into C1 oxygenated products under mild conditions.Compared with previously reported catalysts,it delivers a superior performance of up to 2510.7 mmol·g_(Cu)^(-1)·h^(-1) productivity with a selectivity of around 100%at 80℃for 5 min.Microstructure characterizations and density functional theory(DFT)calculations indicate that TiO_(2) in the mixed phase of anatase and rutile significantly increases the Cu^(+)/CuO ratio of the supported Cu species,and this ratio is linearly related to the formation rate of oxygen-containing species.The CuI site promotes the generation of active O species from H_(2)O_(2) dissociation on Cu_(2)O(111).These active O species reduce the energy barrier for breaking the C-H bond of CH_(4),thus boosting the catalytic activity.The methane conversion mechanism was proposed as a methyl radical pathway to form CH_(3)OH and CH_(3)OOH,and then the generated CH_(3)OH is further oxidized to HOCH_(2)OOH.
基金financially supported by the National Natural Science Foundation of China(No.21801091)the Science Technology Development Planning of Jilin Province(No.20190103117JH)the Education Department Project of Jilin Province(Nos.JJKH20200242KJ and JJKH20190827KJ)。
文摘Solar photocatalysis,as a method of green energy production and sustainable technology,has been regarded as one of the most effective strategies to resolve environmental issues and the current energy crisis.In this work,intimate contact hollow Ni_(x)Co_(1-x)S polyhedron/g-C3N4 nanosheet composites were prepared in-situ through a facile one-step hydrothermal method.The as-prepared Ni_(x)Co_(1-x)S/g-C_(3)N_(4) composites showed superior photocatalytic activity and high stability for H2 generation and methyl orange(MO)degradation under visible light irradiation.The optimized 4 wt.%Ni_(x)Co_(1-x)S/g-C_(3)N_(4) composite attained a maximum H2 evolution rate of 1420μmol g^–1 h^–1,which was about 157 times higher than that of pure g-C3N4.In addition,the Ni_(x)Co_(1-x)S/g-C_(3)N_(4) composite also exhibited greatly improved photocatalytic activity for dye degradation,which for MO was at 98.14%in 9 min.The outstanding photocatalytic performance was predominantly attributed to the unique architecture of hollow Ni_(x)Co_(1-x)S polyhedrons,which not only provided more active sites at the edges and surface as convenient charge transfer channels,but also promoted the separation and transport of electron-hole pairs.This work provides some novel ideas for the design and development of highly efficient noble metal-free cocatalyst/semiconductor systems for photocatalytic H2 generation and dye degradation.
