P507 solvent extraction is the main method to separate and purify the rare earth products.The emulsification may be caused by the impurities in process of extracting rare earths,and these result in huge economic loss ...P507 solvent extraction is the main method to separate and purify the rare earth products.The emulsification may be caused by the impurities in process of extracting rare earths,and these result in huge economic loss and decrease the quality of rare earth products.In recent researches,the extractant was prone to emulsification,and aluminum content of rare earth products also increased,while aluminum concentration of feed was higher.Pointing to this problem,the structural change of saponification P507 extracting aluminum and lanthanum was investigated by infrared spectroscopy,and the results showed that Al ions exchanged with H of P-O-H to become P-O-Al.Because aluminum held the characteristic of hydrophilic after extracted in the form of hydroxyl polymer ions and this provided conditions for the formation of micro emulsion.The organic phase and aqueous phase were investigated by polarizing microscope after aluminum was extracted.The results showed that the organic phase was clear when the extraction capacity of Al was less than 5 g/L.If the extraction capacity of Al exceeded 5 g/L,it formed W/O of ME(micro emulsion),leading to form emulsion of the organic phase.When Al concentration of feed was less than 1 g/L,the aqueous phase would form O/W of ME.If aluminum was extracted by saponification P507 firstly,then the the organic phase loading aluminum extracted rare earth continually,the organic and aqueous phase formed emulsification easily.展开更多
The connotation of rural public goods is expounded.The rural public goods refer to the products and labors that satisfy the production and living of rural residents,economic growth and social progress.The rural public...The connotation of rural public goods is expounded.The rural public goods refer to the products and labors that satisfy the production and living of rural residents,economic growth and social progress.The rural public goods is characterized by non-excludability,non-competitiveness and indispensability of other general public goods.The supply situation of Chinese government to rural public goods is analyzed,as well as the demand situation of rural public goods,which includes farmers' demand on training,the assistance demand of rural weak groups,farmers' demand on comfortable living conditions and farmers' demand on "soft" public goods.The paths for innovating the supply mechanism of rural public goods are put forward,which cover perfecting the decision mechanism of public goods supply;scientifically distributing the supply responsibility of rural public goods;facilitating the reform of each supporting equipment and exploring the multiple capital collecting channels of rural public goods.展开更多
Using acridine dyes as sensitizers,the photoisomerization of three norbornadiene derivatives was investigated.The valence isomerization of nor- bornadiene derivatives(Ⅰ_a,Ⅰ_b,Ⅰ_c)gave their corresponding isomers of...Using acridine dyes as sensitizers,the photoisomerization of three norbornadiene derivatives was investigated.The valence isomerization of nor- bornadiene derivatives(Ⅰ_a,Ⅰ_b,Ⅰ_c)gave their corresponding isomers of quadri- cyclane(Ⅱ_a,Ⅱ_b,Ⅱ_c)operating with relatively high efficiency in an electron transfer mode.Their quantum yields of isomerization were determined and the reaction mechanism was discussed.展开更多
In recent years,with the continuous progress of science and technology,the development of information technology has also begun to change.The popularity of the application of modern information technology in the field...In recent years,with the continuous progress of science and technology,the development of information technology has also begun to change.The popularity of the application of modern information technology in the field of education is very high.College students can obtain the knowledge and content they need from the network.Teachers are no longer the only source of information for students,which promotes the improvement of students academic performance and cultivates students autonomous learning ability.As a university teacher,the author discusses how to motivate college students autonomous learning in the process of virtual project-based practical teaching,hoping that this paper can provide a certain direction for the future development of university education and guide college students to cultivate their autonomous learning ability.展开更多
South Africa strengthens its efforts in polar and ocean research Under the command of Ashley Johnson,the iron gate on the starboard side of the S.A.Agulhas II vessel opened slowly,and the paired bongo nets,supported b...South Africa strengthens its efforts in polar and ocean research Under the command of Ashley Johnson,the iron gate on the starboard side of the S.A.Agulhas II vessel opened slowly,and the paired bongo nets,supported by a mechanised framework,gradually sank 100 metres into the sea.After being towed for a while,they were retrieved,and scientists on board sampled the plankton collected for analysis.Simultaneously,the bongo nets also gathered data on temperature,salinity,conductivity,and depth.Following this,the scientists deployed Niskin bottles to collect water samples from various depths.展开更多
基金Project supported by the National Natural Science Foundation of China (50974042)Scientific Research Special Foundation of Doctor Subject of Chinese Universities (20090042120015)the Fundamental Research Funds for the Central Universities (N090302007)
文摘P507 solvent extraction is the main method to separate and purify the rare earth products.The emulsification may be caused by the impurities in process of extracting rare earths,and these result in huge economic loss and decrease the quality of rare earth products.In recent researches,the extractant was prone to emulsification,and aluminum content of rare earth products also increased,while aluminum concentration of feed was higher.Pointing to this problem,the structural change of saponification P507 extracting aluminum and lanthanum was investigated by infrared spectroscopy,and the results showed that Al ions exchanged with H of P-O-H to become P-O-Al.Because aluminum held the characteristic of hydrophilic after extracted in the form of hydroxyl polymer ions and this provided conditions for the formation of micro emulsion.The organic phase and aqueous phase were investigated by polarizing microscope after aluminum was extracted.The results showed that the organic phase was clear when the extraction capacity of Al was less than 5 g/L.If the extraction capacity of Al exceeded 5 g/L,it formed W/O of ME(micro emulsion),leading to form emulsion of the organic phase.When Al concentration of feed was less than 1 g/L,the aqueous phase would form O/W of ME.If aluminum was extracted by saponification P507 firstly,then the the organic phase loading aluminum extracted rare earth continually,the organic and aqueous phase formed emulsification easily.
文摘The connotation of rural public goods is expounded.The rural public goods refer to the products and labors that satisfy the production and living of rural residents,economic growth and social progress.The rural public goods is characterized by non-excludability,non-competitiveness and indispensability of other general public goods.The supply situation of Chinese government to rural public goods is analyzed,as well as the demand situation of rural public goods,which includes farmers' demand on training,the assistance demand of rural weak groups,farmers' demand on comfortable living conditions and farmers' demand on "soft" public goods.The paths for innovating the supply mechanism of rural public goods are put forward,which cover perfecting the decision mechanism of public goods supply;scientifically distributing the supply responsibility of rural public goods;facilitating the reform of each supporting equipment and exploring the multiple capital collecting channels of rural public goods.
基金the authors thank the help of professor Liang Xiao-guangZhang Bao-wen and Tung Chen-ho of our Institute
文摘Using acridine dyes as sensitizers,the photoisomerization of three norbornadiene derivatives was investigated.The valence isomerization of nor- bornadiene derivatives(Ⅰ_a,Ⅰ_b,Ⅰ_c)gave their corresponding isomers of quadri- cyclane(Ⅱ_a,Ⅱ_b,Ⅱ_c)operating with relatively high efficiency in an electron transfer mode.Their quantum yields of isomerization were determined and the reaction mechanism was discussed.
文摘In recent years,with the continuous progress of science and technology,the development of information technology has also begun to change.The popularity of the application of modern information technology in the field of education is very high.College students can obtain the knowledge and content they need from the network.Teachers are no longer the only source of information for students,which promotes the improvement of students academic performance and cultivates students autonomous learning ability.As a university teacher,the author discusses how to motivate college students autonomous learning in the process of virtual project-based practical teaching,hoping that this paper can provide a certain direction for the future development of university education and guide college students to cultivate their autonomous learning ability.
文摘South Africa strengthens its efforts in polar and ocean research Under the command of Ashley Johnson,the iron gate on the starboard side of the S.A.Agulhas II vessel opened slowly,and the paired bongo nets,supported by a mechanised framework,gradually sank 100 metres into the sea.After being towed for a while,they were retrieved,and scientists on board sampled the plankton collected for analysis.Simultaneously,the bongo nets also gathered data on temperature,salinity,conductivity,and depth.Following this,the scientists deployed Niskin bottles to collect water samples from various depths.
