Since a-tocopherol has special biological and nutritional activities, it is important to convert non-a-tocopherols to a-tocopherol. This paper focuses on the effects of residence time, pressure, temperature and the ma...Since a-tocopherol has special biological and nutritional activities, it is important to convert non-a-tocopherols to a-tocopherol. This paper focuses on the effects of residence time, pressure, temperature and the mass ratio of formaldehyde to tocopherols on the content of a-tocopherol, the conversion of non-a-tocopherols, the selectivity and yield of a-tocopherol in a fixed-bed reactor. The reactor is made from φ12 (I.D.)×360mm stainless steel pipe. It is packed with a mixture of 5% Pd/C and cation exchange resin catalysts. Preliminary results indicated the suitable operation conditions are pressure 5.0 MPa, temperature 180℃, and mass ratio of formaldehyde to tocopherols 2.0. A product of more than 50% a-tocopherol content has been obtained by using 88.85% mixed tocopherols as raw material.展开更多
GLO-PEM is driven by soil moisture data of AMSR-E and PAR(Photosynthetically active radiation) which is retrieved from MODIS atmospheric data product in this paper.Using remote sensing data can overcome uncertainty br...GLO-PEM is driven by soil moisture data of AMSR-E and PAR(Photosynthetically active radiation) which is retrieved from MODIS atmospheric data product in this paper.Using remote sensing data can overcome uncertainty brought from interpola-tion of precipitation and PAR.Comparing with observed radiation data,PAR retrieved by remote sensing is in high accuracy in this study.RMSE is 9 and 19.68 W m 2 and R2 is 0.89 and 0.67 respectively.As a result of GLO-PEM,annual total amount of NPP of Qinghai-Tibet Plateau is 0.37 Pg C a-1 in 2005 2008.There is a significant linear relationship between field and simu-lated NPP.Determination coefficient reached 0.93.NPP is decrease from southeast to northwest in the Qinghai-Tibet Plateau.NPP changes from 0 to 1500 g C m-2 a-1.There is different limit factors of vegetation growth in west and east plateau.In the west of 450 mm rainfall line,the limit factors is precipitation.In the east of 450 mm rainfall line,temperature is the dominated factor of vegetation growth.展开更多
基金the Natural Science Foundation of Zhejiang Province (001103231-01-02).
文摘Since a-tocopherol has special biological and nutritional activities, it is important to convert non-a-tocopherols to a-tocopherol. This paper focuses on the effects of residence time, pressure, temperature and the mass ratio of formaldehyde to tocopherols on the content of a-tocopherol, the conversion of non-a-tocopherols, the selectivity and yield of a-tocopherol in a fixed-bed reactor. The reactor is made from φ12 (I.D.)×360mm stainless steel pipe. It is packed with a mixture of 5% Pd/C and cation exchange resin catalysts. Preliminary results indicated the suitable operation conditions are pressure 5.0 MPa, temperature 180℃, and mass ratio of formaldehyde to tocopherols 2.0. A product of more than 50% a-tocopherol content has been obtained by using 88.85% mixed tocopherols as raw material.
基金supported by the National Basic Research Program of Chi-na (Grant Nos.2009CB421105,2010CB951600 and 2010CB950900)the National Science and Technology Key Project Support Program (Grant No.2009BAC61B01)
文摘GLO-PEM is driven by soil moisture data of AMSR-E and PAR(Photosynthetically active radiation) which is retrieved from MODIS atmospheric data product in this paper.Using remote sensing data can overcome uncertainty brought from interpola-tion of precipitation and PAR.Comparing with observed radiation data,PAR retrieved by remote sensing is in high accuracy in this study.RMSE is 9 and 19.68 W m 2 and R2 is 0.89 and 0.67 respectively.As a result of GLO-PEM,annual total amount of NPP of Qinghai-Tibet Plateau is 0.37 Pg C a-1 in 2005 2008.There is a significant linear relationship between field and simu-lated NPP.Determination coefficient reached 0.93.NPP is decrease from southeast to northwest in the Qinghai-Tibet Plateau.NPP changes from 0 to 1500 g C m-2 a-1.There is different limit factors of vegetation growth in west and east plateau.In the west of 450 mm rainfall line,the limit factors is precipitation.In the east of 450 mm rainfall line,temperature is the dominated factor of vegetation growth.
