The similarities between life processes that exhibit oscillatory behavior and chemical oscillating systems impel people to think that the biological and abiological phenomena conform to the same law. Oscillating chemi...The similarities between life processes that exhibit oscillatory behavior and chemical oscillating systems impel people to think that the biological and abiological phenomena conform to the same law. Oscillating chemical systems have been the focus of much research in the area of theoretical and experimental chemical dynamics as well as analytical sciences in recent years, but the studies on the perturbation species are kept around the concentration level of 10 -7 mol/L. In our experiment, an amazed phenomenon was found. Ultra trace level (10 -20 mol/L) of H 2O 2 can cause so magnitude influence on the macro system (MnSO 4 KBrO 3 diacetone oscillating chemical system) that the effect can be observed by a macroscopical method. When the concentration of H 2O 2 is above 10 -13 mol/L , the oscillation can even be stopped. A further study on the mechanism will doubtlessly help to understand the mystery of life, such as the sudden cardiopathy and the metabolism failure.展开更多
Lignocellulosic materials can be used as biosorbent for refinement of the wastewaters when they are available in large quantities. Many studies were conducted to uptake Cu(Ⅱ) ion from aqueous solutions.In this paper,...Lignocellulosic materials can be used as biosorbent for refinement of the wastewaters when they are available in large quantities. Many studies were conducted to uptake Cu(Ⅱ) ion from aqueous solutions.In this paper, the biosorption efficiency of Cu(Ⅱ) ions from a synthetic aqueous solution was investigated using Gundelia tournefortii(GT), without any pre-treatment. Fourier transform infrared spectroscopy,scanning electron microscopy and determining the point of zero charge were employed to characterise the biosorbent. Batch experiments were performed to study the influence of p H, biosorbent dosage, contact time, temperature and initial Cu(Ⅱ) concentration on Cu(Ⅱ) removal. The biosorption isotherms were investigated using the Langmuir, Freundlich, Temkin and D-R isotherm models. The findings show that the biosorption isotherm was better fitted by the Langmuir equation and the maximum adsorption capacity of GT was found to be 38.7597 mg·g^-1. The kinetics data were analysed by pseudo-first order,pseudo-second order, and intra-particle diffusion equations. The results indicate that the pseudosecond-order model was found to explain the adsorption kinetics most effectively. The values of thermodynamic parameters including Gibbs free energy(△G°), enthalpy(△H°), and entropy(△S°) demonstrate that the biosorption process was exothermic and spontaneous. The multiple nonlinear regression(MnLR)and artificial neural network(ANN) analyses were applied for the prediction of biosorption capacity. A relationship between the predicted and observed data was obtained and the results show that the Mn LR and ANN models provided successful predictions.展开更多
The nonlinear fractional point reactor kinetics equation in the presence of Newtonian temperature reactivity feedback with a multi-group of delayed neutrons,which describes the spectrum behavior of neutron density int...The nonlinear fractional point reactor kinetics equation in the presence of Newtonian temperature reactivity feedback with a multi-group of delayed neutrons,which describes the spectrum behavior of neutron density into the homogenous nuclear reactors, is developed. This system is one of the most important stiff coupled nonlinear fractional differentials for nuclear reactor dynamics. The generalization of Taylor's formula that involves Caputo fractional derivatives is developed in an attempt to overcome the difficulty of the stiffness of the nonlinear fractional differential model. Moreover, the general fractional derivatives are calculated analytically throughout this work. Furthermore, the local and global estimated errors were analyzed, which suggest that the error quantification should take into account the possible grow in time of the error. This observation provides a motivation for going beyond more classical local-in-time concepts of error(local truncation error). The neutron density response with time is analyzed for the anomalous diffusion, sub-diffusion, and super-diffusion processes.展开更多
Optical solitons—stable waves balancing delicately between nonlinearities and dispersive effects—have advanced the field of ultrafast optics and dynamics,with contributions spanning from supercontinuum generation to...Optical solitons—stable waves balancing delicately between nonlinearities and dispersive effects—have advanced the field of ultrafast optics and dynamics,with contributions spanning from supercontinuum generation to soliton fission,optical event horizons,Hawking radiation and optical rogue waves,among others.Here,we investigate picojoule soliton dynamics in silicon slow-light,photonic-bandgap waveguides under the influence of Drude-modeled,free-carrier-induced nonlinear effects.Using real-time and single-shot amplified dispersive Fourier transform spectroscopy simultaneously with high-fidelity cross-correlation frequency resolved optical gating at femtojoule sensitivity and femtosecond resolution,we examine the soliton stability limits,the soliton dynamics including free-carrier quartic slow-light scaling and acceleration,and the Drude electron–hole plasma-induced perturbations in the Cherenkov radiation and modulation instability.Our real-time single-shot and time-averaged cross-correlation measurements are matched with our detailed theoretical modeling,examining the reduced group velocity free-carrier kinetics on solitons at the picojoule scale.展开更多
文摘The similarities between life processes that exhibit oscillatory behavior and chemical oscillating systems impel people to think that the biological and abiological phenomena conform to the same law. Oscillating chemical systems have been the focus of much research in the area of theoretical and experimental chemical dynamics as well as analytical sciences in recent years, but the studies on the perturbation species are kept around the concentration level of 10 -7 mol/L. In our experiment, an amazed phenomenon was found. Ultra trace level (10 -20 mol/L) of H 2O 2 can cause so magnitude influence on the macro system (MnSO 4 KBrO 3 diacetone oscillating chemical system) that the effect can be observed by a macroscopical method. When the concentration of H 2O 2 is above 10 -13 mol/L , the oscillation can even be stopped. A further study on the mechanism will doubtlessly help to understand the mystery of life, such as the sudden cardiopathy and the metabolism failure.
基金the School of Mining, College of Engineering, University of Tehran for supporting this research
文摘Lignocellulosic materials can be used as biosorbent for refinement of the wastewaters when they are available in large quantities. Many studies were conducted to uptake Cu(Ⅱ) ion from aqueous solutions.In this paper, the biosorption efficiency of Cu(Ⅱ) ions from a synthetic aqueous solution was investigated using Gundelia tournefortii(GT), without any pre-treatment. Fourier transform infrared spectroscopy,scanning electron microscopy and determining the point of zero charge were employed to characterise the biosorbent. Batch experiments were performed to study the influence of p H, biosorbent dosage, contact time, temperature and initial Cu(Ⅱ) concentration on Cu(Ⅱ) removal. The biosorption isotherms were investigated using the Langmuir, Freundlich, Temkin and D-R isotherm models. The findings show that the biosorption isotherm was better fitted by the Langmuir equation and the maximum adsorption capacity of GT was found to be 38.7597 mg·g^-1. The kinetics data were analysed by pseudo-first order,pseudo-second order, and intra-particle diffusion equations. The results indicate that the pseudosecond-order model was found to explain the adsorption kinetics most effectively. The values of thermodynamic parameters including Gibbs free energy(△G°), enthalpy(△H°), and entropy(△S°) demonstrate that the biosorption process was exothermic and spontaneous. The multiple nonlinear regression(MnLR)and artificial neural network(ANN) analyses were applied for the prediction of biosorption capacity. A relationship between the predicted and observed data was obtained and the results show that the Mn LR and ANN models provided successful predictions.
文摘The nonlinear fractional point reactor kinetics equation in the presence of Newtonian temperature reactivity feedback with a multi-group of delayed neutrons,which describes the spectrum behavior of neutron density into the homogenous nuclear reactors, is developed. This system is one of the most important stiff coupled nonlinear fractional differentials for nuclear reactor dynamics. The generalization of Taylor's formula that involves Caputo fractional derivatives is developed in an attempt to overcome the difficulty of the stiffness of the nonlinear fractional differential model. Moreover, the general fractional derivatives are calculated analytically throughout this work. Furthermore, the local and global estimated errors were analyzed, which suggest that the error quantification should take into account the possible grow in time of the error. This observation provides a motivation for going beyond more classical local-in-time concepts of error(local truncation error). The neutron density response with time is analyzed for the anomalous diffusion, sub-diffusion, and super-diffusion processes.
基金support is from the Office of Naval Research with grant N00014-14-1-0041UESTC Young Faculty Award ZYGX2015KYQD051+2 种基金the 111 project(B14039)funding from NSFC Grant 61070040funding from AFOSR Young Investigator Award with grant FA9550-15-1-0081.
文摘Optical solitons—stable waves balancing delicately between nonlinearities and dispersive effects—have advanced the field of ultrafast optics and dynamics,with contributions spanning from supercontinuum generation to soliton fission,optical event horizons,Hawking radiation and optical rogue waves,among others.Here,we investigate picojoule soliton dynamics in silicon slow-light,photonic-bandgap waveguides under the influence of Drude-modeled,free-carrier-induced nonlinear effects.Using real-time and single-shot amplified dispersive Fourier transform spectroscopy simultaneously with high-fidelity cross-correlation frequency resolved optical gating at femtojoule sensitivity and femtosecond resolution,we examine the soliton stability limits,the soliton dynamics including free-carrier quartic slow-light scaling and acceleration,and the Drude electron–hole plasma-induced perturbations in the Cherenkov radiation and modulation instability.Our real-time single-shot and time-averaged cross-correlation measurements are matched with our detailed theoretical modeling,examining the reduced group velocity free-carrier kinetics on solitons at the picojoule scale.
