A new process named CPP (Catalytic Pyrolysis Process) for producing ethylene andpropylene from heavy oil feedstock has been developed. The catalyst CEP was specially designedfor this process, which has bi-functional c...A new process named CPP (Catalytic Pyrolysis Process) for producing ethylene andpropylene from heavy oil feedstock has been developed. The catalyst CEP was specially designedfor this process, which has bi-functional catalytic activities for both carbonium ion reaction andfree radical reaction, so as to maximize the yields of ethylene and propylene. The commercial trialshowed that the yield of ethylene and propylene was 20.37% and 18.23% respectively inmaximum ethylene operation with Daqing AR as feedstock, and the yield of ethylene and propylenewas 9.77% and 24.60% respectively in maximum propylene operation by using the same feedstock.Compared with steam cracker, the feed cost of CPP is much lower for producing ethylene andpropylene.展开更多
Traditionally, the evaluation of pollen-based quantitative paleoclimate reconstructions focuses on the ability of calibration sets to infer present climatic conditions and/or the similarity between fossil and modem as...Traditionally, the evaluation of pollen-based quantitative paleoclimate reconstructions focuses on the ability of calibration sets to infer present climatic conditions and/or the similarity between fossil and modem assemblages. Objective criteria for choosing the most appropriate climate parameter（s） to be reconstructed at a specific site are thus lacking. Using a novel approach for testing the statistical significance of a quantitative reconstruction using random environmental data, in combination with the advantageous large environmental gradients, abundant vegetation types and comprehensive modem pollen databases in China, we describe a new procedure for pollen-based quantitative paleoclimatic reconstructions. First, the most significant environmental variable controlling the fossil pollen assemblage changes is identified. Second, a calibration set to infer changes in this targeted variable is built up, by limiting the modem ranges of other environmental variables. Finally, the pollen-based quantitative reconstruction is obtained and its statistical significance assessed. This novel procedure was used to reconstruct the mean annual precipitation （Pann） from Gonghai Lake in the Lvliang Mountains, and Tianchi Lake in the Liupan Mountains, on the eastern and western fringe of the Chinese Loess Plateau, respectively. Both Pann. reconstructions are statistically significant （p〈0.001）, and a sound and stable correlation relationship exists in their common period, showing a rapid precipitation decrease since 3300 cal yr BP. Thus, we propose that this procedure has great potential for reducing the uncertainties associated with pollen-based quantitative paleoclimatic reconstructions in China.展开更多
Currently,aliasing error of temporal signal model becomes the main factor constraining the accuracy of temporal gravity field.In provision of three types of satellite formations,i.e.,GRACE-type,Pendulum-type and n-s-C...Currently,aliasing error of temporal signal model becomes the main factor constraining the accuracy of temporal gravity field.In provision of three types of satellite formations,i.e.,GRACE-type,Pendulum-type and n-s-Cartwheel-type,which are suitable for gravity mission and composed of observation in different directions,here we design two cases and conduct a simulation experiment on the feasibility to apply satellite formations for eliminating the influence from the aliasing error of ocean tide models.The result of our experiment shows that,when the aliasing error is disregarded,n-s-Cartwheel formation can provide the best conditions for gravity field determination,which,compared with GRACE-type,can improve the accuracy by 43%.When aliasing error of the ocean tide model acts as the main source of error,the satellite formation applied in dynamic method for gravity field inversion cannot eliminate aliasing or improve the accuracy of gravity field.And due to its higher sensitivity to the high-degree variation of gravity field,the Cartwheel-type formation,which includes the radial observation,can result in the gravity field containing more high-frequency signals for the ocean tide model error,and lead to a dramatically larger error.展开更多
文摘A new process named CPP (Catalytic Pyrolysis Process) for producing ethylene andpropylene from heavy oil feedstock has been developed. The catalyst CEP was specially designedfor this process, which has bi-functional catalytic activities for both carbonium ion reaction andfree radical reaction, so as to maximize the yields of ethylene and propylene. The commercial trialshowed that the yield of ethylene and propylene was 20.37% and 18.23% respectively inmaximum ethylene operation with Daqing AR as feedstock, and the yield of ethylene and propylenewas 9.77% and 24.60% respectively in maximum propylene operation by using the same feedstock.Compared with steam cracker, the feed cost of CPP is much lower for producing ethylene andpropylene.
基金supported by the National Natural Science Foundation of China(Grant Nos.41471162&41571182)the National Key R&D Program of China(Grant No.2017YFA0603402)
文摘Traditionally, the evaluation of pollen-based quantitative paleoclimate reconstructions focuses on the ability of calibration sets to infer present climatic conditions and/or the similarity between fossil and modem assemblages. Objective criteria for choosing the most appropriate climate parameter（s） to be reconstructed at a specific site are thus lacking. Using a novel approach for testing the statistical significance of a quantitative reconstruction using random environmental data, in combination with the advantageous large environmental gradients, abundant vegetation types and comprehensive modem pollen databases in China, we describe a new procedure for pollen-based quantitative paleoclimatic reconstructions. First, the most significant environmental variable controlling the fossil pollen assemblage changes is identified. Second, a calibration set to infer changes in this targeted variable is built up, by limiting the modem ranges of other environmental variables. Finally, the pollen-based quantitative reconstruction is obtained and its statistical significance assessed. This novel procedure was used to reconstruct the mean annual precipitation （Pann） from Gonghai Lake in the Lvliang Mountains, and Tianchi Lake in the Liupan Mountains, on the eastern and western fringe of the Chinese Loess Plateau, respectively. Both Pann. reconstructions are statistically significant （p〈0.001）, and a sound and stable correlation relationship exists in their common period, showing a rapid precipitation decrease since 3300 cal yr BP. Thus, we propose that this procedure has great potential for reducing the uncertainties associated with pollen-based quantitative paleoclimatic reconstructions in China.
基金supported by the National Basic Research Program of China(Grant No.2013CB733302)the Basic Research Project of Institute of Earthquake Science,China Earthquake Administration(Grant Nos.2013IES0203,2014IES010102)the National Natural Science Foundation of China(Grant No.41304018)
文摘Currently,aliasing error of temporal signal model becomes the main factor constraining the accuracy of temporal gravity field.In provision of three types of satellite formations,i.e.,GRACE-type,Pendulum-type and n-s-Cartwheel-type,which are suitable for gravity mission and composed of observation in different directions,here we design two cases and conduct a simulation experiment on the feasibility to apply satellite formations for eliminating the influence from the aliasing error of ocean tide models.The result of our experiment shows that,when the aliasing error is disregarded,n-s-Cartwheel formation can provide the best conditions for gravity field determination,which,compared with GRACE-type,can improve the accuracy by 43%.When aliasing error of the ocean tide model acts as the main source of error,the satellite formation applied in dynamic method for gravity field inversion cannot eliminate aliasing or improve the accuracy of gravity field.And due to its higher sensitivity to the high-degree variation of gravity field,the Cartwheel-type formation,which includes the radial observation,can result in the gravity field containing more high-frequency signals for the ocean tide model error,and lead to a dramatically larger error.
