In this paper, a linear relationship between the logarithm of capacity factor k and normal boiling point to of the homologues has been derived, based on the basic retention equation of liquid chromatography according ...In this paper, a linear relationship between the logarithm of capacity factor k and normal boiling point to of the homologues has been derived, based on the basic retention equation of liquid chromatography according to statistical thermodyoamics proposed by professor Ln Peizhang and others, This equation has been verified by a large number of experimental data, all the strsight lines of lnk- of bumologues for different mobile phass coaiposltion cross each other at the same point, So the intereection point equation van proposed, wbich was used to prodict the retention valu, the result was satisfactory.展开更多
Based on the intersection point rule of the retention value and normal boiling point of homologues in reversed-phase high-performance liquid chromatography(RPLC), the intersection point rule of the retention value of ...Based on the intersection point rule of the retention value and normal boiling point of homologues in reversed-phase high-performance liquid chromatography(RPLC), the intersection point rule of the retention value of homologues and mobile phase composition has been derived, and was testified by a lot of experimental data from the literature. With this newly proposed equation, we can use the retention value of the compound in one mobile phase composition to predict its retention value in any other mobile phase composition. For fourteen groups of homologues in five mobile phase compositions on five Kinds of columns, the overall average absolute error of 721 data sets is 2.8%.展开更多
A study on relationship between molecular structure and chromatographic retention values for realizing the identification and prediction of chromatographic retention values has been the major task of chromatographic t...A study on relationship between molecular structure and chromatographic retention values for realizing the identification and prediction of chromatographic retention values has been the major task of chromatographic thermodynamics. In 1964, Prof. Lu Peizhang established the relationship between molecular structural parameters and chromatographic retention values in gas-liquid chromatography by using statistical thermodynamical methods. Based on his work, some Chinese researchers have performed the prediction of chromatographic retention values.展开更多
The goal of this study was to evaluate the water retention value （WRV） of a test solid substrate and a fungal cell in solid state fermentation （SSF）. WRV is the ratio of the weight of water retained after centrifu...The goal of this study was to evaluate the water retention value （WRV） of a test solid substrate and a fungal cell in solid state fermentation （SSF）. WRV is the ratio of the weight of water retained after centrifugation under specific conditions by a wet sample to the oven dry weight of the same sample. SSF refers to the microbial fermentation, which takes place in the absence or near absence of free water, thus being close to the natural environment. Many factors are involved in a successful SSF process. In addition to biological parameters, the SSF process is also dependent on physical factors such as WRV. A centrifugal technique has been modified and applied to the evaluation of WRV. Wheat bran, soybean hulls and rapeseed meal were used as model substrate. Aspergillus awamori and Aspergillus oryzae were used as model microorganism. Results revealed that the ability of wheat bran to retain water in the solid substrate is 56% higher than that of soybean hulls and rapeseed meal. In the term of fungal cell, the ability of A. oryzae to retain water in the cells was higher （73% higher） than that ofA. awamori. In addition, through oven method moisture content loss from A. awamori is 46% higher than that from A. oryzae during drying process. Nevertheless, it can be seen that A. oryzae is able to retain water content about 5 times higher than A. awamori. Through this results, we found that WRV varies depending on solid substrates and microorganisms. This initial information can be beneficial in the SSF process to be carried out.展开更多
Acrylamide-sodium acrylate copolymer hydrogels have been obtained by radiation techniques. Two different methods have been used to introduce—COONa groups into polymer chains of the gels: (1) by partial hydrolysis of ...Acrylamide-sodium acrylate copolymer hydrogels have been obtained by radiation techniques. Two different methods have been used to introduce—COONa groups into polymer chains of the gels: (1) by partial hydrolysis of acrylamide homopolymer gel; (2) by direct copolymerization and crosslinking of acrylamide and sodium acrylate in aqueous solutions. It was found that the gels obtained in different ways had different properties, the swelling character of the gels obtained by partial hydrolysis were more sensitive to pH of swelling aqueous media, in order to explain these differences, ^(13)C-NMR techniques were used to investigate the sequence distribution of monomer units of both gels.展开更多
文摘In this paper, a linear relationship between the logarithm of capacity factor k and normal boiling point to of the homologues has been derived, based on the basic retention equation of liquid chromatography according to statistical thermodyoamics proposed by professor Ln Peizhang and others, This equation has been verified by a large number of experimental data, all the strsight lines of lnk- of bumologues for different mobile phass coaiposltion cross each other at the same point, So the intereection point equation van proposed, wbich was used to prodict the retention valu, the result was satisfactory.
文摘Based on the intersection point rule of the retention value and normal boiling point of homologues in reversed-phase high-performance liquid chromatography(RPLC), the intersection point rule of the retention value of homologues and mobile phase composition has been derived, and was testified by a lot of experimental data from the literature. With this newly proposed equation, we can use the retention value of the compound in one mobile phase composition to predict its retention value in any other mobile phase composition. For fourteen groups of homologues in five mobile phase compositions on five Kinds of columns, the overall average absolute error of 721 data sets is 2.8%.
基金present address: Dalian Institute of Chemical Physics, Dalian.
文摘A study on relationship between molecular structure and chromatographic retention values for realizing the identification and prediction of chromatographic retention values has been the major task of chromatographic thermodynamics. In 1964, Prof. Lu Peizhang established the relationship between molecular structural parameters and chromatographic retention values in gas-liquid chromatography by using statistical thermodynamical methods. Based on his work, some Chinese researchers have performed the prediction of chromatographic retention values.
文摘The goal of this study was to evaluate the water retention value （WRV） of a test solid substrate and a fungal cell in solid state fermentation （SSF）. WRV is the ratio of the weight of water retained after centrifugation under specific conditions by a wet sample to the oven dry weight of the same sample. SSF refers to the microbial fermentation, which takes place in the absence or near absence of free water, thus being close to the natural environment. Many factors are involved in a successful SSF process. In addition to biological parameters, the SSF process is also dependent on physical factors such as WRV. A centrifugal technique has been modified and applied to the evaluation of WRV. Wheat bran, soybean hulls and rapeseed meal were used as model substrate. Aspergillus awamori and Aspergillus oryzae were used as model microorganism. Results revealed that the ability of wheat bran to retain water in the solid substrate is 56% higher than that of soybean hulls and rapeseed meal. In the term of fungal cell, the ability of A. oryzae to retain water in the cells was higher （73% higher） than that ofA. awamori. In addition, through oven method moisture content loss from A. awamori is 46% higher than that from A. oryzae during drying process. Nevertheless, it can be seen that A. oryzae is able to retain water content about 5 times higher than A. awamori. Through this results, we found that WRV varies depending on solid substrates and microorganisms. This initial information can be beneficial in the SSF process to be carried out.
文摘Acrylamide-sodium acrylate copolymer hydrogels have been obtained by radiation techniques. Two different methods have been used to introduce—COONa groups into polymer chains of the gels: (1) by partial hydrolysis of acrylamide homopolymer gel; (2) by direct copolymerization and crosslinking of acrylamide and sodium acrylate in aqueous solutions. It was found that the gels obtained in different ways had different properties, the swelling character of the gels obtained by partial hydrolysis were more sensitive to pH of swelling aqueous media, in order to explain these differences, ^(13)C-NMR techniques were used to investigate the sequence distribution of monomer units of both gels.
