Ignition delay of syngas is an important factor that affects stable operation of combustor and adding diluents to syngas can reduce NO_x emission.This paper used H_2O,CO_2 and N_2 as diluents and calculated ignition d...Ignition delay of syngas is an important factor that affects stable operation of combustor and adding diluents to syngas can reduce NO_x emission.This paper used H_2O,CO_2 and N_2 as diluents and calculated ignition delay of syngas in temperature range of 900-1400 K and at pressures of 10 and 30 atm respectively.In high temperature range,comparing with N_2 dilution,adding H_2O and CO_2 can significantly inhibit autoignition of syngas because they have higher collision efficiencies in reaction H + O_2(+ M) = HO_2(+ M).As for low temperature conditions,adding H_2O can increase reactivity of syngas,especially under high pressure,because of its high collision efficiency in reaction H_2O_2(+ M) = 2OH(+ M).Comparing with different dilution rates shows that for syngas and operating conditions in this paper,adding N_2 mainly influences temperature rising process of syngas combustion,thus inhibiting reactivity of syngas.In addition,this paper calculated ignition delay of syngas at different equivalence ratios(φ= 0.5,1.0).Higher equivalence ratio(φ≤1) means that less air(especially N_2) needs to be heated,thus promoting ignition of syngas,展开更多
A novel dual-loop technique was proposed for single-mode selection in an optoelectronic oscillator （OEO）. It consisted of a pump laser and a feedback circuit including an intensity modulator, a Fabry-Perot （FP） et...A novel dual-loop technique was proposed for single-mode selection in an optoelectronic oscillator （OEO）. It consisted of a pump laser and a feedback circuit including an intensity modulator, a Fabry-Perot （FP） etalon, two optical fiber delay lines, two photodetectors, and an amplifier. By inserting the Fabry-Perot etalon, the proposed dual-loop OEO realized a single mode oscillation ranging from 0 Hz to 20 GHz. The strong oscillation mode was present at 15 GHz, and the side modes suppression ratio （SMSR） exceeded 140dB. More over the length of the two fiber loops were just 5 meters and 36 meters.展开更多
In this paper a delayed mathematical model for tumor growth under the action of external inhibitors is studied. The delay represents the time taken for cells to undergo mitosis. External inhibitor means that an inhibi...In this paper a delayed mathematical model for tumor growth under the action of external inhibitors is studied. The delay represents the time taken for cells to undergo mitosis. External inhibitor means that an inhibitor is either developed from the immune system of the body or administered by medical treatment to distinguish with that secreted by tumor itself. Non-negativity of solutions is studied. Local and global stabilities of the stationary solutions are proved for some parameter values. The analysis of the effect of inhibitor＇s parameters on tumor＇s growth is presented. The results show that dynamical behavior of solutions of this model is similar to that of solutions for corresponding nondelayed model for some parameter values.展开更多
基金Supported by National High Technology Research and Development Program of China(2009AA05Z310)
文摘Ignition delay of syngas is an important factor that affects stable operation of combustor and adding diluents to syngas can reduce NO_x emission.This paper used H_2O,CO_2 and N_2 as diluents and calculated ignition delay of syngas in temperature range of 900-1400 K and at pressures of 10 and 30 atm respectively.In high temperature range,comparing with N_2 dilution,adding H_2O and CO_2 can significantly inhibit autoignition of syngas because they have higher collision efficiencies in reaction H + O_2(+ M) = HO_2(+ M).As for low temperature conditions,adding H_2O can increase reactivity of syngas,especially under high pressure,because of its high collision efficiency in reaction H_2O_2(+ M) = 2OH(+ M).Comparing with different dilution rates shows that for syngas and operating conditions in this paper,adding N_2 mainly influences temperature rising process of syngas combustion,thus inhibiting reactivity of syngas.In addition,this paper calculated ignition delay of syngas at different equivalence ratios(φ= 0.5,1.0).Higher equivalence ratio(φ≤1) means that less air(especially N_2) needs to be heated,thus promoting ignition of syngas,
文摘A novel dual-loop technique was proposed for single-mode selection in an optoelectronic oscillator （OEO）. It consisted of a pump laser and a feedback circuit including an intensity modulator, a Fabry-Perot （FP） etalon, two optical fiber delay lines, two photodetectors, and an amplifier. By inserting the Fabry-Perot etalon, the proposed dual-loop OEO realized a single mode oscillation ranging from 0 Hz to 20 GHz. The strong oscillation mode was present at 15 GHz, and the side modes suppression ratio （SMSR） exceeded 140dB. More over the length of the two fiber loops were just 5 meters and 36 meters.
文摘In this paper a delayed mathematical model for tumor growth under the action of external inhibitors is studied. The delay represents the time taken for cells to undergo mitosis. External inhibitor means that an inhibitor is either developed from the immune system of the body or administered by medical treatment to distinguish with that secreted by tumor itself. Non-negativity of solutions is studied. Local and global stabilities of the stationary solutions are proved for some parameter values. The analysis of the effect of inhibitor＇s parameters on tumor＇s growth is presented. The results show that dynamical behavior of solutions of this model is similar to that of solutions for corresponding nondelayed model for some parameter values.
