The kinetics of I-->N transition of a side chain nematic polymethacrylate has been studied by small angle depolarized light scattering intensity measurements using a charge coupled device linear image sensor. The p...The kinetics of I-->N transition of a side chain nematic polymethacrylate has been studied by small angle depolarized light scattering intensity measurements using a charge coupled device linear image sensor. The polymer shows the transition temperatures K52N79I in degreesC, The H-v scattering intensity T(q,t) during the transition I (at 80.2degreesC)-->N (at 75.8degreesC) shows that T(q) is independent of q for all t, and during the initial stage (in 6 s) T(t) increases exponentially with t. In the later stage of the transition T(t) approaches a saturation value in 2 min. This experimental result indicates that the I-->N transition of a liquid crystalline polymer is a spinodal type of phase transition mediated by orientation fluctuation.展开更多
The interaction between monosaccharides exhibits an important role in the assembly of monosaccharide-containing molecules. In this work, three common monosaccharides, glucose, galactose and mannose, are employed to in...The interaction between monosaccharides exhibits an important role in the assembly of monosaccharide-containing molecules. In this work, three common monosaccharides, glucose, galactose and mannose, are employed to investigate the effect of monosaccharide on the self-assembly of benzenetricarboxamide(BTA) core-containing molecules. In the presence of monosaccharides, three benzenetricarboxamide derivatives aggregate into different ordered structures. When alanine linkers are introduced to these molecules between the core and the monosacchride, morphologies of three types of monosaccharide BTAs turned to disordered, meanwhile their structures become similar with the increase of the length of alanine linkers, indicating the disappearance of the monosaccharide effects.展开更多
Whether the ATP sensitive potassium channel opener pinacidil can provide myocardial protective effects in prolonged isolated global ischemic rat heart was investigated. On modified isolated rat working heart model, 4...Whether the ATP sensitive potassium channel opener pinacidil can provide myocardial protective effects in prolonged isolated global ischemic rat heart was investigated. On modified isolated rat working heart model, 40 hearts were divided into four groups randomly: Hyperpolarized arrest H K solution containing pinacidil (50 μmol/L) (P1 and P2) and depolarized arrest St. Thomas' solution (S1 and S2) subjected to 15 ℃ hypothermia, 60 min (P1 and S1) or 120 min (P1 and S2) of ischemia and 30 min reperfusion. The experimental indices included cardioplegic efficiency, cardiac function, coronary blood flow, myocardial enzyme release, myocardial water and ATP content. Hyperpolarized arrest provided significantly better recovery of cardiac function than depolarized arrest. Postischemic coronary flow and myocardial ATP content were higher. The arrest time of electro mechanical activities were longer than depolarized arrest. There were no differences among the groups in myocardial water contents. The hyperpolarized arrest solution containing pinacidil can provide a marked myocardial protective effect during prolonged hypothermic myocardial ischemia.展开更多
It was demonstrated that some level of order exists in glassy poly(ethylene terephthalate) by depolarized light intensity(DLI) technique, but this order is different from that in crystalline PET. The degree of order i...It was demonstrated that some level of order exists in glassy poly(ethylene terephthalate) by depolarized light intensity(DLI) technique, but this order is different from that in crystalline PET. The degree of order in glassy PET decrease with increasing temperature between 288-343 K. The active energy of this transition is about 22 56 kJ/mol. The IR analysis indicated that this order relates to gauche structure of the ethyleneglycol fragments. The decrease of order with temperature comes from the increase of distance between the order segments.展开更多
Application of an oxygen-depolarized cathode will contribute to energy saving in chlor-alkali electrolysis. For this purpose, the development of high-performance cathode with the best electrocatalyst is essential. Usi...Application of an oxygen-depolarized cathode will contribute to energy saving in chlor-alkali electrolysis. For this purpose, the development of high-performance cathode with the best electrocatalyst is essential. Using bimetallic Pt-based alloy electrocatalysts including PtPd and PtAg carbon-supported in oxygen-depolarized cathode chlor-alkali cell has been shown to have the high cell performance. This study presents application of PtRu carbon supported electrocatalyst oxygen-depolarized cathode and performance comparison of cells with carbon-supported PtRu, PtPd and PtAg electrocatalysts cathodes using the same DSA-Cl2 anode. Results show that there are quite similarity between the effects of various factors on the caustic current efficiency (CCE) in a zero-gap oxygen-depolarized chlor-alkali cells employing carbon-supported PtPd, PtRu and PtAg electrocatalysts. Besides, it seems that the PtPd/C electrocatalyst cathode has relatively higher performance than the other cathodes with PtAg/C and PtRu/C electrocatalysts in zero-gap chlor-alkali cells.展开更多
基金This work was supported by the National Key Projects for Fundamental Research, "Macromolecular Condensed State" of Ministry of Science and Technology of China.
文摘The kinetics of I-->N transition of a side chain nematic polymethacrylate has been studied by small angle depolarized light scattering intensity measurements using a charge coupled device linear image sensor. The polymer shows the transition temperatures K52N79I in degreesC, The H-v scattering intensity T(q,t) during the transition I (at 80.2degreesC)-->N (at 75.8degreesC) shows that T(q) is independent of q for all t, and during the initial stage (in 6 s) T(t) increases exponentially with t. In the later stage of the transition T(t) approaches a saturation value in 2 min. This experimental result indicates that the I-->N transition of a liquid crystalline polymer is a spinodal type of phase transition mediated by orientation fluctuation.
基金The Ministry of Science and Technology of China and the National Natural Science Foundation of China(Nos.91527305 and 51322306)are acknowledged for their financial support
文摘The interaction between monosaccharides exhibits an important role in the assembly of monosaccharide-containing molecules. In this work, three common monosaccharides, glucose, galactose and mannose, are employed to investigate the effect of monosaccharide on the self-assembly of benzenetricarboxamide(BTA) core-containing molecules. In the presence of monosaccharides, three benzenetricarboxamide derivatives aggregate into different ordered structures. When alanine linkers are introduced to these molecules between the core and the monosacchride, morphologies of three types of monosaccharide BTAs turned to disordered, meanwhile their structures become similar with the increase of the length of alanine linkers, indicating the disappearance of the monosaccharide effects.
基金This project was supported by a grant from EducationalMinistry Foundation of China (No.[2 0 0 1]34 5 )
文摘Whether the ATP sensitive potassium channel opener pinacidil can provide myocardial protective effects in prolonged isolated global ischemic rat heart was investigated. On modified isolated rat working heart model, 40 hearts were divided into four groups randomly: Hyperpolarized arrest H K solution containing pinacidil (50 μmol/L) (P1 and P2) and depolarized arrest St. Thomas' solution (S1 and S2) subjected to 15 ℃ hypothermia, 60 min (P1 and S1) or 120 min (P1 and S2) of ischemia and 30 min reperfusion. The experimental indices included cardioplegic efficiency, cardiac function, coronary blood flow, myocardial enzyme release, myocardial water and ATP content. Hyperpolarized arrest provided significantly better recovery of cardiac function than depolarized arrest. Postischemic coronary flow and myocardial ATP content were higher. The arrest time of electro mechanical activities were longer than depolarized arrest. There were no differences among the groups in myocardial water contents. The hyperpolarized arrest solution containing pinacidil can provide a marked myocardial protective effect during prolonged hypothermic myocardial ischemia.
文摘It was demonstrated that some level of order exists in glassy poly(ethylene terephthalate) by depolarized light intensity(DLI) technique, but this order is different from that in crystalline PET. The degree of order in glassy PET decrease with increasing temperature between 288-343 K. The active energy of this transition is about 22 56 kJ/mol. The IR analysis indicated that this order relates to gauche structure of the ethyleneglycol fragments. The decrease of order with temperature comes from the increase of distance between the order segments.
文摘Application of an oxygen-depolarized cathode will contribute to energy saving in chlor-alkali electrolysis. For this purpose, the development of high-performance cathode with the best electrocatalyst is essential. Using bimetallic Pt-based alloy electrocatalysts including PtPd and PtAg carbon-supported in oxygen-depolarized cathode chlor-alkali cell has been shown to have the high cell performance. This study presents application of PtRu carbon supported electrocatalyst oxygen-depolarized cathode and performance comparison of cells with carbon-supported PtRu, PtPd and PtAg electrocatalysts cathodes using the same DSA-Cl2 anode. Results show that there are quite similarity between the effects of various factors on the caustic current efficiency (CCE) in a zero-gap oxygen-depolarized chlor-alkali cells employing carbon-supported PtPd, PtRu and PtAg electrocatalysts. Besides, it seems that the PtPd/C electrocatalyst cathode has relatively higher performance than the other cathodes with PtAg/C and PtRu/C electrocatalysts in zero-gap chlor-alkali cells.
