The general dynamic features of the batch oxidation of Sulfur(-Ⅱ) compounds (S2-,thiosuifae, thiocynate and thiourea et al. ) were discussed. The changes of pH with reaction time consist of a rise and two separate dr...The general dynamic features of the batch oxidation of Sulfur(-Ⅱ) compounds (S2-,thiosuifae, thiocynate and thiourea et al. ) were discussed. The changes of pH with reaction time consist of a rise and two separate drops. Dynamic model was proposed, further experimental studies on the batch oxidation of thiourea and thiocyanate by ClO2- were also canied out. Simulation curve was well consistent with experiment in a batch reactor.Non-catalytic oscillation of peroxide (hydrogen peroxide, persulfate et al. ) - S(-Ⅱ)-compound system resulted from the nonlinear dynamic of sulfur oxidation. In the oxidation of S(-Ⅱ)-compounds by oxyhalogen compounds(ClO2 - et al. ), nonlinear dynamics of both oxyhalogen compound and suifur compound should be considered simultaneously. So complex phenomena such as birhythmicity and chaos may be discovered.展开更多
The Ruettimnann’ s method[5] for vitamin K1 synthesis has been improved by usingphase transfer catalyst in Diels-Alder condensation and using mixed trans-cis phytyl chlorideinstead of natural phytol as starting mater...The Ruettimnann’ s method[5] for vitamin K1 synthesis has been improved by usingphase transfer catalyst in Diels-Alder condensation and using mixed trans-cis phytyl chlorideinstead of natural phytol as starting material in the synthesis. The vitamin K1 then obtainedby a retro-Diels-Alder reaction has a cis-trans isomer ratio of 20. 35 to 79. 65 which meets theChinese pharmacopia standard. Phytyl bromide in this case gave vitamin K1 with cis-trans ratio of 26. 30 to 73. 70.展开更多
文摘The general dynamic features of the batch oxidation of Sulfur(-Ⅱ) compounds (S2-,thiosuifae, thiocynate and thiourea et al. ) were discussed. The changes of pH with reaction time consist of a rise and two separate drops. Dynamic model was proposed, further experimental studies on the batch oxidation of thiourea and thiocyanate by ClO2- were also canied out. Simulation curve was well consistent with experiment in a batch reactor.Non-catalytic oscillation of peroxide (hydrogen peroxide, persulfate et al. ) - S(-Ⅱ)-compound system resulted from the nonlinear dynamic of sulfur oxidation. In the oxidation of S(-Ⅱ)-compounds by oxyhalogen compounds(ClO2 - et al. ), nonlinear dynamics of both oxyhalogen compound and suifur compound should be considered simultaneously. So complex phenomena such as birhythmicity and chaos may be discovered.
文摘The Ruettimnann’ s method[5] for vitamin K1 synthesis has been improved by usingphase transfer catalyst in Diels-Alder condensation and using mixed trans-cis phytyl chlorideinstead of natural phytol as starting material in the synthesis. The vitamin K1 then obtainedby a retro-Diels-Alder reaction has a cis-trans isomer ratio of 20. 35 to 79. 65 which meets theChinese pharmacopia standard. Phytyl bromide in this case gave vitamin K1 with cis-trans ratio of 26. 30 to 73. 70.
