The paper introduces the research progress in an emergency decision support system for marine pollution （EDSS） in China seas and elaborates on the possible role of the Neutron Activation Analysis （NAA） method ther...The paper introduces the research progress in an emergency decision support system for marine pollution （EDSS） in China seas and elaborates on the possible role of the Neutron Activation Analysis （NAA） method therein. To deal with the increasingly grave situation of offshore pollution, the EDSS for China seas has been researching and developing. Based on the prediction and analysis of the ocean three-dimensional current field, this system makes an inference on the possible path of diffusion and influencing area of marine pollutants and possible location of pollution source, and in combination with the environmentally sensitive information related to the technical integration of GIS, it puts forward the decision, making support for minimizing the hazard caused by pollutants. This system has been operationalized and running for many years on the Bohai and Huanghai seas＇ Marine Pollutants Prediction and Early-Warning, and it has achieved successful experience for many times in the emergencies of China＇s coastal pollution accidents. At present, the environmental guarantee system directed against heavy metals and radioactive pollutants is in the experimental stage. As the NAA method is especially applicable to the detection of part of heavy metals and radioactive substances, it is of very important practical value for the new system to realize the monitoring, prediction and early-warning of ocean heavy metals and radioactive pollutants.展开更多
[Objective] The aim was to explore the optimal conditions for the catalytic synthesis of geranyl propionate. [Method] The synthesis of mesoporous molecular sieves Al-MCM-41 was carried out in an open-vessel. The mesop...[Objective] The aim was to explore the optimal conditions for the catalytic synthesis of geranyl propionate. [Method] The synthesis of mesoporous molecular sieves Al-MCM-41 was carried out in an open-vessel. The mesoporous structure of as-synthesized Al-MCM-41 was characterized by X-ray diffraction （XRD） pattern, Fourier transform infrared （FT-IR） spectrum, NH3-Temperature Programmed Desorption （TPD）, and N2 adsorption-desorption isotherms. The catalytic performances of Al-MCM-41 for the synthesis of geranyl propionate （GP） with geraniol and propionic acid as reagents also were investigated. [Result] The as-synthesized Al-MCM-41 possesses typical hexagonal mesoporous structure with high long-range order and crystalline degree. Based on the systematic investigation of reaction time, temperature, amount ratio of reagents and regeneration of catalyst, the optimum reaction conditions were obtained with molar ratio of geraniol to propionic acid of 1.0∶1.5, reaction temperature of 120 ℃ and reaction time of 8 h. The high GP selectivity of 70.01% with geraniol conversion of 40.01% was achieved under above optimum conditions. The catalyst inactivation can be observed after five catalytic cycles. The regeneration of inactivated catalyst with high activity and selectivity can be achieved by calcination treatment to remove the carbon deposition, which covers the acid site of catalyst. [Conclusion] The optimal conditions for the synthesis of geranyl propionate were obtained.展开更多
Vegetation evolution in the northern South China Sea region since 40 500 a BP is reconstructed using biomization procedure based on pollen data from deep sea core 17940. The result shows that, it is feasible to recons...Vegetation evolution in the northern South China Sea region since 40 500 a BP is reconstructed using biomization procedure based on pollen data from deep sea core 17940. The result shows that, it is feasible to reconstruct palaeovegetation using biomization procedure, when pollen, particularly Pinus pollen, transported by mind over long distance is excluded. Results from factor analysis suggest that humidity and temperature are the two main factors determining vegetation evolution on land around the northern South China Sea. From 40 500 a BP to 11 100 a BP, broad-leaved evergreen forest (WAMF), and montane conifers(MGRF) occurred on hills and low mountains; while steppe (STEP) predominated on the exposed shelf. The main feature of the vegetation evolution is the frequent alternation between MGRF (or WAMF) and STEP, implying abrupt changes in millennium scale between humid/cold and dry/temperate climate. All abrupt climate events could be broadly correlated with Henrich events and Dansggard-Oscherge events. One of the events around 12 700 a BP, sees the occurrence of MGRF, suggesting that climate turned humid and cold rapidly. This may be correlated with the Younger Dryas event; Broad-leaved evergreen (WAMF) predominates since 11 000 a BP. During the early Holocene and late Holocene tropical rainforest (TRFO) or tropical seasonal forest (TSFO) occurred several times.展开更多
[Objective] This paper analyzed present status of broomcorn millet produc- tion in China, including cultivation methods, fertilization utilization, diseases, insect pests and disasters, machinery development, planting...[Objective] This paper analyzed present status of broomcorn millet produc- tion in China, including cultivation methods, fertilization utilization, diseases, insect pests and disasters, machinery development, planting benefit and other aspects. [Method] The corn millet data reported by China Industrial and Technological Re- search System of Millet in 2011 were analyzed by descriptive statistical analysis of EXCEL. [Result] The results show that 17 678.57 kg/ha of farm manure, 155.77 kg/ha of urea, 259.5 kg/ha of compound fertilizer, 203.13 kg/ha of phosphate fertilizer and 75 kg/ha of potash fertilizer were used in China; the national mechanization degree of broomcorn millet production is lower than 30% in all; the average income of broomcorn millet production is 10 503.33 yuan/ha, and the VCR is 2.64; most broomcorn millet producing areas are affected by mild pests and diseases, very few are affected by mild and moderate pests and diseases, and the impact of natural disasters is the lightest. [~onclusien] Currently fertilizer utilization for broomcorn millet is proper but the mechanization level and planting benefit are low, natural disasters, pests and diseases are not severe; finally the authors proposed some suggestions on the fertilizer utilization, mechanization production, benefit increasing, disaster warning, disease and insect controlling and government policy-making for broomcorn millet production.展开更多
The two novel green oxidation processes of p/o-cresols to p/o-hydroxybenzaldehydes catalyzed by metalloporphyrins in the presence of molecular oxygen were developed in this work.Among the metalloporphyrins with differ...The two novel green oxidation processes of p/o-cresols to p/o-hydroxybenzaldehydes catalyzed by metalloporphyrins in the presence of molecular oxygen were developed in this work.Among the metalloporphyrins with different central ions and substituents studied,T(p-NO 2)PPCoCl and T(p-OCH 3)PPFeCl presented the highest activities for p-cresol and o-cresol oxidation reactions respectively.The molar ratio of sodium hydroxide to cresols and different reaction parameters including reaction temperature,reaction time and reaction pressure have been investigated,and 69.8%/50.4% conversions of p/o-cresol and 86.6%/26.6% selectivities for p/o-hydroxybenzaldehydes were reached under optimized conditions.展开更多
The history,the major achievements in both methodology and applications,the current trends and future perspectives of neutron activation analysis (NAA) in China are briefly described.
基金supported by the National Natural Science Foundation of China(41206013,41376014,41430963)the Public Science and Technology Research Funds Projects of Ocean (201205018)+5 种基金Key Marine Science Foundation of the State Oceanic Administration of China for Young Scholar(2013203,2012202,2012223)National Sci-Tech Support Plan(2014BAB12B02)Tianjin Sci-Tech Support Plan(14ZCZDSF00012)POL Visiting Fellowship Program (Song Jun)China Scholarship Council ([2008]3019[2012]3013)
文摘The paper introduces the research progress in an emergency decision support system for marine pollution （EDSS） in China seas and elaborates on the possible role of the Neutron Activation Analysis （NAA） method therein. To deal with the increasingly grave situation of offshore pollution, the EDSS for China seas has been researching and developing. Based on the prediction and analysis of the ocean three-dimensional current field, this system makes an inference on the possible path of diffusion and influencing area of marine pollutants and possible location of pollution source, and in combination with the environmentally sensitive information related to the technical integration of GIS, it puts forward the decision, making support for minimizing the hazard caused by pollutants. This system has been operationalized and running for many years on the Bohai and Huanghai seas＇ Marine Pollutants Prediction and Early-Warning, and it has achieved successful experience for many times in the emergencies of China＇s coastal pollution accidents. At present, the environmental guarantee system directed against heavy metals and radioactive pollutants is in the experimental stage. As the NAA method is especially applicable to the detection of part of heavy metals and radioactive substances, it is of very important practical value for the new system to realize the monitoring, prediction and early-warning of ocean heavy metals and radioactive pollutants.
基金Supported by Scientific and Technological Key Project of Henan Province(112102310424)~~
文摘[Objective] The aim was to explore the optimal conditions for the catalytic synthesis of geranyl propionate. [Method] The synthesis of mesoporous molecular sieves Al-MCM-41 was carried out in an open-vessel. The mesoporous structure of as-synthesized Al-MCM-41 was characterized by X-ray diffraction （XRD） pattern, Fourier transform infrared （FT-IR） spectrum, NH3-Temperature Programmed Desorption （TPD）, and N2 adsorption-desorption isotherms. The catalytic performances of Al-MCM-41 for the synthesis of geranyl propionate （GP） with geraniol and propionic acid as reagents also were investigated. [Result] The as-synthesized Al-MCM-41 possesses typical hexagonal mesoporous structure with high long-range order and crystalline degree. Based on the systematic investigation of reaction time, temperature, amount ratio of reagents and regeneration of catalyst, the optimum reaction conditions were obtained with molar ratio of geraniol to propionic acid of 1.0∶1.5, reaction temperature of 120 ℃ and reaction time of 8 h. The high GP selectivity of 70.01% with geraniol conversion of 40.01% was achieved under above optimum conditions. The catalyst inactivation can be observed after five catalytic cycles. The regeneration of inactivated catalyst with high activity and selectivity can be achieved by calcination treatment to remove the carbon deposition, which covers the acid site of catalyst. [Conclusion] The optimal conditions for the synthesis of geranyl propionate were obtained.
文摘Vegetation evolution in the northern South China Sea region since 40 500 a BP is reconstructed using biomization procedure based on pollen data from deep sea core 17940. The result shows that, it is feasible to reconstruct palaeovegetation using biomization procedure, when pollen, particularly Pinus pollen, transported by mind over long distance is excluded. Results from factor analysis suggest that humidity and temperature are the two main factors determining vegetation evolution on land around the northern South China Sea. From 40 500 a BP to 11 100 a BP, broad-leaved evergreen forest (WAMF), and montane conifers(MGRF) occurred on hills and low mountains; while steppe (STEP) predominated on the exposed shelf. The main feature of the vegetation evolution is the frequent alternation between MGRF (or WAMF) and STEP, implying abrupt changes in millennium scale between humid/cold and dry/temperate climate. All abrupt climate events could be broadly correlated with Henrich events and Dansggard-Oscherge events. One of the events around 12 700 a BP, sees the occurrence of MGRF, suggesting that climate turned humid and cold rapidly. This may be correlated with the Younger Dryas event; Broad-leaved evergreen (WAMF) predominates since 11 000 a BP. During the early Holocene and late Holocene tropical rainforest (TRFO) or tropical seasonal forest (TSFO) occurred several times.
基金Supported by Special Fund for Construction of Modern Agricultural Technology System(CARS-07-12.5-A18)~~
文摘[Objective] This paper analyzed present status of broomcorn millet produc- tion in China, including cultivation methods, fertilization utilization, diseases, insect pests and disasters, machinery development, planting benefit and other aspects. [Method] The corn millet data reported by China Industrial and Technological Re- search System of Millet in 2011 were analyzed by descriptive statistical analysis of EXCEL. [Result] The results show that 17 678.57 kg/ha of farm manure, 155.77 kg/ha of urea, 259.5 kg/ha of compound fertilizer, 203.13 kg/ha of phosphate fertilizer and 75 kg/ha of potash fertilizer were used in China; the national mechanization degree of broomcorn millet production is lower than 30% in all; the average income of broomcorn millet production is 10 503.33 yuan/ha, and the VCR is 2.64; most broomcorn millet producing areas are affected by mild pests and diseases, very few are affected by mild and moderate pests and diseases, and the impact of natural disasters is the lightest. [~onclusien] Currently fertilizer utilization for broomcorn millet is proper but the mechanization level and planting benefit are low, natural disasters, pests and diseases are not severe; finally the authors proposed some suggestions on the fertilizer utilization, mechanization production, benefit increasing, disaster warning, disease and insect controlling and government policy-making for broomcorn millet production.
基金Supported by the Key Project of National Natural Science Foundation of China (21036009, 20776003)the Key Project of Natural Science Foundation of Beijing (2061001)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of the Beijing Municipality (PHR 200907105, PHR 201107104)
文摘The two novel green oxidation processes of p/o-cresols to p/o-hydroxybenzaldehydes catalyzed by metalloporphyrins in the presence of molecular oxygen were developed in this work.Among the metalloporphyrins with different central ions and substituents studied,T(p-NO 2)PPCoCl and T(p-OCH 3)PPFeCl presented the highest activities for p-cresol and o-cresol oxidation reactions respectively.The molar ratio of sodium hydroxide to cresols and different reaction parameters including reaction temperature,reaction time and reaction pressure have been investigated,and 69.8%/50.4% conversions of p/o-cresol and 86.6%/26.6% selectivities for p/o-hydroxybenzaldehydes were reached under optimized conditions.
文摘The history,the major achievements in both methodology and applications,the current trends and future perspectives of neutron activation analysis (NAA) in China are briefly described.
