Interaction of anionic polyelectrolyte with cationic gemini surfactant has been investigated by coarse-grained molecular dynamics simulation.Polyelectrolyte facilitates the oppositely charged ionic surfactants to aggr...Interaction of anionic polyelectrolyte with cationic gemini surfactant has been investigated by coarse-grained molecular dynamics simulation.Polyelectrolyte facilitates the oppositely charged ionic surfactants to aggregate by suppressing the electrostatic repulsion between ionic head groups leading to the formation of micellar complex.With addition of surfactant,the conformation of polyion chain changes from stretched to random coiled to spherical,and at the same time more free micelles are formed by surfactants in mixtures.Increasing the length of spacer or tail chain in gemini surfactant will weaken its interaction with polyelectrolyte and simultaneously strengthen its tendency to self-assemble.The simulation results are consistent with experimental observations and reveal that the electrostatic interaction plays an important role in the interaction of polyelectrolyte with gemini sur- factant.展开更多
This experiment was carried out in order to investigate the effect of diurnal temperature fluctuations on seed germination of Pistacia vera L. The seeds of Badami-e-Zarand and Sarakhs cultivars were treated with the f...This experiment was carried out in order to investigate the effect of diurnal temperature fluctuations on seed germination of Pistacia vera L. The seeds of Badami-e-Zarand and Sarakhs cultivars were treated with the following temperatures： T1 = 24 hr at 25℃, T2= 16 hr at 25 ℃ ＋ 8 hr at 10 ℃, T3= 12 hr at 25 ℃ ＋ 12 hr at 10℃ and T4= 8 hr at 25℃ ＋ 16 hr at 10℃. The germination percentage was increased by diurnal temperature fluctuations, however all of treatments extended MTG compared to control （T1）. Temperature affected the quality of roots, in a matter that high constant temperature resulted in dichotomous （forked） roots during seed germination of pistachio. The response of cultivars was different in this case, so that, Badami-e-Zarand had higher dichotomous root percentage. This disorder can be decreased by diurnal temperature fluctuation.展开更多
基金Supported by the National Natural Science Foundation of China （No.20476025）, the Doctoral Research Foundation of the Ministry of Education of China （No.20050251004）, E-institute of Shanghai High Institution Grid （No.200303） and Shanghai Municipal Science and Technology Commission of China （No.05DJ14002）.
文摘Interaction of anionic polyelectrolyte with cationic gemini surfactant has been investigated by coarse-grained molecular dynamics simulation.Polyelectrolyte facilitates the oppositely charged ionic surfactants to aggregate by suppressing the electrostatic repulsion between ionic head groups leading to the formation of micellar complex.With addition of surfactant,the conformation of polyion chain changes from stretched to random coiled to spherical,and at the same time more free micelles are formed by surfactants in mixtures.Increasing the length of spacer or tail chain in gemini surfactant will weaken its interaction with polyelectrolyte and simultaneously strengthen its tendency to self-assemble.The simulation results are consistent with experimental observations and reveal that the electrostatic interaction plays an important role in the interaction of polyelectrolyte with gemini sur- factant.
文摘This experiment was carried out in order to investigate the effect of diurnal temperature fluctuations on seed germination of Pistacia vera L. The seeds of Badami-e-Zarand and Sarakhs cultivars were treated with the following temperatures： T1 = 24 hr at 25℃, T2= 16 hr at 25 ℃ ＋ 8 hr at 10 ℃, T3= 12 hr at 25 ℃ ＋ 12 hr at 10℃ and T4= 8 hr at 25℃ ＋ 16 hr at 10℃. The germination percentage was increased by diurnal temperature fluctuations, however all of treatments extended MTG compared to control （T1）. Temperature affected the quality of roots, in a matter that high constant temperature resulted in dichotomous （forked） roots during seed germination of pistachio. The response of cultivars was different in this case, so that, Badami-e-Zarand had higher dichotomous root percentage. This disorder can be decreased by diurnal temperature fluctuation.
