The reaction heat effect analysis for the aromatization process of Liquefied Petroleum Gas (LPG) was completed in this paper. In order to characterize this complex reaction system, one set of independent reactions was...The reaction heat effect analysis for the aromatization process of Liquefied Petroleum Gas (LPG) was completed in this paper. In order to characterize this complex reaction system, one set of independent reactions was determined by means of atomic coefficient matrix method. Based on reaction thermodynamic and stoichiometric knowledge, the heat effect, Gibbs free energy change and equilibrium constant for each independent reaction was calculated for the specified conditions. Under these conditions, based on the initial and final composition data from LPG aromatization experiments, the actual extent of reaction for each independent reaction was determined. Furthermore, the global reaction heat and adiabatic temperature rise of LPG aromatization reaction system could be estimated. This work would provide a theoretical guidance for the design and scale-up of reactor for LPG aromatization process, as well as for the selection of proper operating conditions.展开更多
The frequently used concept of "global reaction" is discussed and the reason for the confusion behind explained. The misconception is cleared by formula writing based on the donor–acceptor(donac) reaction c...The frequently used concept of "global reaction" is discussed and the reason for the confusion behind explained. The misconception is cleared by formula writing based on the donor–acceptor(donac) reaction concept and by applying the Grand Rule of Formula Writing that is based on it.展开更多
The Global Reaction Model describes a set of chemical reactions that can potentially occur during the process of obtaining silicon rich oxide (SRO) films, regardless of the technique used to grow such films which are ...The Global Reaction Model describes a set of chemical reactions that can potentially occur during the process of obtaining silicon rich oxide (SRO) films, regardless of the technique used to grow such films which are an outside stoichiometry material. Particularly, chemical reactions that occur during the process of growing of SRO films by LPCVD technique are highlighted in this model. We suggest and evaluate either some types of molecules or resulting nanostructures and we predict theoretically, by applying the density functional theory, the contribution that they may have to the phenomenon of luminescence which is measured in SRO films. Also, we have calculated the opto-electronic properties of SRO films. The suggested model provides enough information required to identify the molecular structures resulting from the presence of defects in SRO films and also those corresponding to charged structures. It is also possible to detect the molecular structures which are modified due to the effect of heat treatment, and identify the presence of different oxidation states inclusive the formation of siloxanes.展开更多
This note studies the global solutions of a semilineear reaction diffusion system which comes from an exothermic themical reaction.This is a complement of paper[1]and gives a positive answer to the question mentioned...This note studies the global solutions of a semilineear reaction diffusion system which comes from an exothermic themical reaction.This is a complement of paper[1]and gives a positive answer to the question mentioned by paper[2].展开更多
In this paper we deal with the initial boundary value problem for two classes of reaction diffusion systems with two source terms in bounded domain. Under some assumptions on the exponents and the initial data, applyi...In this paper we deal with the initial boundary value problem for two classes of reaction diffusion systems with two source terms in bounded domain. Under some assumptions on the exponents and the initial data, applying the comparison principle, the maximum prin- ciple and the supersolution-subsolution method, we prove the global existence and blow up of solutions. We also establish some upper blow up rates.展开更多
An increase of carbon dioxide content accompanied by an increase of the temperature is observed in the atmosphere during the last 200 years. This behaviour can be explained by examination of correlations between tree ...An increase of carbon dioxide content accompanied by an increase of the temperature is observed in the atmosphere during the last 200 years. This behaviour can be explained by examination of correlations between tree generally accepted data sets of the recent past, world population, carbon dioxide content in the atmosphere, and rise of global temperature as function of time. No return to climate situations from hundred thousand of years before present is necessary. The world climate is a dynamic equilibrium between all energy generating processes on earth, especially sun energy, and the radiation of energy into space. Since approx. 200 years the dynamic equilibrium is changed additionally by means of fossil energy carriers, whose depots were put on in passed geological epochs, a climatic disturbance was produced. It is shown that the consumption of energy per year by the mankind can warm up the atmosphere by about one degree. This quantity cannot be neglected in climatic calculations;therefore it is the cause of mankind made warming of the atmosphere. The qualitative analyses presented here have shown that the use of so-called renewable energy sources does not necessarily lead to the avoidance of global warming. It can be expected that some techniques will have no or even small effect. Especially the model calculations to the operation of wind turbines and its influence on the temperature of the atmosphere show that it is difficult to estimate their influence and cannot be foreknown.展开更多
This paper is concerned with an Initial Boundary Value Problem (IBVP) for a strongly coupled semilinear reaction-diffusion system. By using the upper and lower solutions method and Leray-Schauder fixed point theorem a...This paper is concerned with an Initial Boundary Value Problem (IBVP) for a strongly coupled semilinear reaction-diffusion system. By using the upper and lower solutions method and Leray-Schauder fixed point theorem and so on, the authors prove the global existence and uniqueness of a. smooth. solution for this IBVP under some appropriate conditions.展开更多
This paper deals with the reaction diffusion equation in domain, Omega = R or Omega = (-L, L) with L < infinity. Let A(L) and A be the global attractor of this equation corresponding to Omega = (-L,L) and Omega = R...This paper deals with the reaction diffusion equation in domain, Omega = R or Omega = (-L, L) with L < infinity. Let A(L) and A be the global attractor of this equation corresponding to Omega = (-L,L) and Omega = R, respectively. It is showed that the global attractor A is upper semicontinuity at 0 with respect to the sets {A(L)} in some sense.展开更多
The purpose of this work is to study the global existence and asymptotic behavior of solutions to a coupled reaction-diffusion system describing epidemiological or chemical situations. Our analytical proofs are based ...The purpose of this work is to study the global existence and asymptotic behavior of solutions to a coupled reaction-diffusion system describing epidemiological or chemical situations. Our analytical proofs are based on the Lyapunov functional methods.展开更多
Statistical mechanics and semi-empirical molecular orbital theory (PM6) are used to calculate the surface coverage of CO2 and H2 molecular species chemically adsorbed on the surface of Cu and Zn micro clusters. The ca...Statistical mechanics and semi-empirical molecular orbital theory (PM6) are used to calculate the surface coverage of CO2 and H2 molecular species chemically adsorbed on the surface of Cu and Zn micro clusters. The calculation shows that CO2 is adsorbed well both on the surface of Cu and Zn micro clusters. Although H2 is adsorbed well on the surface of Zn micro clusters, H2 absorption on the surface of Cu micro clusters is much more limited in the pressure range of 20 - 100 atm and temperature range of 200 - 1000 K. Reaction rates are also estimated for some chemical adsorption process of H2 gas using theory of absolute reaction rates. It is found that the values of the reaction rate calculated in the present paper agree reasonably well with the experimental values.展开更多
A set of new global phenomenological optical model potential parameters has been obtained in the mass range of target nuclei 220≤A≤260 with incident energies below 300 MeV, by simultaneously fitting the experimental...A set of new global phenomenological optical model potential parameters has been obtained in the mass range of target nuclei 220≤A≤260 with incident energies below 300 MeV, by simultaneously fitting the experimental data of 232Th and 23Su, and these potential parameters are analyzed and used to calculate the reaction cross sections, energy spectra and double differ- ential cross sections for p＋232Th reaction. Comparison of calculated results using these potential parameters with available experimental data shows that the present form of global optical model potential could reproduce experimental data for both the neutron and the proton.展开更多
In this paper, we considered a homogeneous reaction-diffusion predator-prey system with Holling type II functional response subject to Neumann boundary conditions. Some new sufficient conditions were analytically esta...In this paper, we considered a homogeneous reaction-diffusion predator-prey system with Holling type II functional response subject to Neumann boundary conditions. Some new sufficient conditions were analytically established to ensure that this system has globally asymptotically stable equilibria and Hopf bifurcation surrounding interior equilibrium. In the analysis of Hopf bifurcation, based on the phenomenon of Turing instability and well-done conditions, the system undergoes a Hopf bifurcation and an example incorporating with numerical simulations to support the existence of Hopf bifurcation is presented. We also derived a useful algorithm for determining direction of Hopf bifurcation and stability of bifurcating periodic solutions correspond to j ≠0 and j = 0, respectively. Finally, all these theoretical results are expected to be useful in the future study of dynamical complexity of ecological environment.展开更多
The initial boundary value problem of wave equations and reaction-diffusion equations with several nonlinear source terms in a bounded domain is studied by potential well method. The invarianee of some sets under the ...The initial boundary value problem of wave equations and reaction-diffusion equations with several nonlinear source terms in a bounded domain is studied by potential well method. The invarianee of some sets under the flow of these problems and the vacuum isolation of solutions are obtained by introducing a family of potential wells. Then the threshold result of global existence and nonexistence of solutions are given. Finally, the problem with critical initial conditions are discussed.展开更多
文摘The reaction heat effect analysis for the aromatization process of Liquefied Petroleum Gas (LPG) was completed in this paper. In order to characterize this complex reaction system, one set of independent reactions was determined by means of atomic coefficient matrix method. Based on reaction thermodynamic and stoichiometric knowledge, the heat effect, Gibbs free energy change and equilibrium constant for each independent reaction was calculated for the specified conditions. Under these conditions, based on the initial and final composition data from LPG aromatization experiments, the actual extent of reaction for each independent reaction was determined. Furthermore, the global reaction heat and adiabatic temperature rise of LPG aromatization reaction system could be estimated. This work would provide a theoretical guidance for the design and scale-up of reactor for LPG aromatization process, as well as for the selection of proper operating conditions.
文摘The frequently used concept of "global reaction" is discussed and the reason for the confusion behind explained. The misconception is cleared by formula writing based on the donor–acceptor(donac) reaction concept and by applying the Grand Rule of Formula Writing that is based on it.
文摘The Global Reaction Model describes a set of chemical reactions that can potentially occur during the process of obtaining silicon rich oxide (SRO) films, regardless of the technique used to grow such films which are an outside stoichiometry material. Particularly, chemical reactions that occur during the process of growing of SRO films by LPCVD technique are highlighted in this model. We suggest and evaluate either some types of molecules or resulting nanostructures and we predict theoretically, by applying the density functional theory, the contribution that they may have to the phenomenon of luminescence which is measured in SRO films. Also, we have calculated the opto-electronic properties of SRO films. The suggested model provides enough information required to identify the molecular structures resulting from the presence of defects in SRO films and also those corresponding to charged structures. It is also possible to detect the molecular structures which are modified due to the effect of heat treatment, and identify the presence of different oxidation states inclusive the formation of siloxanes.
文摘This note studies the global solutions of a semilineear reaction diffusion system which comes from an exothermic themical reaction.This is a complement of paper[1]and gives a positive answer to the question mentioned by paper[2].
基金supported by the National Natural Science Foundation of China(11471087)the China Postdoctoral Science Foundation(2013M540270)+1 种基金the Heilongjiang Postdoctoral Foundation(LBH-Z13056,LBHZ15036)the Fundamental Research Funds for the Central Universities
文摘In this paper we deal with the initial boundary value problem for two classes of reaction diffusion systems with two source terms in bounded domain. Under some assumptions on the exponents and the initial data, applying the comparison principle, the maximum prin- ciple and the supersolution-subsolution method, we prove the global existence and blow up of solutions. We also establish some upper blow up rates.
文摘An increase of carbon dioxide content accompanied by an increase of the temperature is observed in the atmosphere during the last 200 years. This behaviour can be explained by examination of correlations between tree generally accepted data sets of the recent past, world population, carbon dioxide content in the atmosphere, and rise of global temperature as function of time. No return to climate situations from hundred thousand of years before present is necessary. The world climate is a dynamic equilibrium between all energy generating processes on earth, especially sun energy, and the radiation of energy into space. Since approx. 200 years the dynamic equilibrium is changed additionally by means of fossil energy carriers, whose depots were put on in passed geological epochs, a climatic disturbance was produced. It is shown that the consumption of energy per year by the mankind can warm up the atmosphere by about one degree. This quantity cannot be neglected in climatic calculations;therefore it is the cause of mankind made warming of the atmosphere. The qualitative analyses presented here have shown that the use of so-called renewable energy sources does not necessarily lead to the avoidance of global warming. It can be expected that some techniques will have no or even small effect. Especially the model calculations to the operation of wind turbines and its influence on the temperature of the atmosphere show that it is difficult to estimate their influence and cannot be foreknown.
文摘This paper is concerned with an Initial Boundary Value Problem (IBVP) for a strongly coupled semilinear reaction-diffusion system. By using the upper and lower solutions method and Leray-Schauder fixed point theorem and so on, the authors prove the global existence and uniqueness of a. smooth. solution for this IBVP under some appropriate conditions.
文摘This paper deals with the reaction diffusion equation in domain, Omega = R or Omega = (-L, L) with L < infinity. Let A(L) and A be the global attractor of this equation corresponding to Omega = (-L,L) and Omega = R, respectively. It is showed that the global attractor A is upper semicontinuity at 0 with respect to the sets {A(L)} in some sense.
文摘The purpose of this work is to study the global existence and asymptotic behavior of solutions to a coupled reaction-diffusion system describing epidemiological or chemical situations. Our analytical proofs are based on the Lyapunov functional methods.
文摘Statistical mechanics and semi-empirical molecular orbital theory (PM6) are used to calculate the surface coverage of CO2 and H2 molecular species chemically adsorbed on the surface of Cu and Zn micro clusters. The calculation shows that CO2 is adsorbed well both on the surface of Cu and Zn micro clusters. Although H2 is adsorbed well on the surface of Zn micro clusters, H2 absorption on the surface of Cu micro clusters is much more limited in the pressure range of 20 - 100 atm and temperature range of 200 - 1000 K. Reaction rates are also estimated for some chemical adsorption process of H2 gas using theory of absolute reaction rates. It is found that the values of the reaction rate calculated in the present paper agree reasonably well with the experimental values.
基金supported by the China Ministry of Science and Technology (No. 2007CB209903)National Basic Research Program of China(973 Program)
文摘A set of new global phenomenological optical model potential parameters has been obtained in the mass range of target nuclei 220≤A≤260 with incident energies below 300 MeV, by simultaneously fitting the experimental data of 232Th and 23Su, and these potential parameters are analyzed and used to calculate the reaction cross sections, energy spectra and double differ- ential cross sections for p＋232Th reaction. Comparison of calculated results using these potential parameters with available experimental data shows that the present form of global optical model potential could reproduce experimental data for both the neutron and the proton.
文摘In this paper, we considered a homogeneous reaction-diffusion predator-prey system with Holling type II functional response subject to Neumann boundary conditions. Some new sufficient conditions were analytically established to ensure that this system has globally asymptotically stable equilibria and Hopf bifurcation surrounding interior equilibrium. In the analysis of Hopf bifurcation, based on the phenomenon of Turing instability and well-done conditions, the system undergoes a Hopf bifurcation and an example incorporating with numerical simulations to support the existence of Hopf bifurcation is presented. We also derived a useful algorithm for determining direction of Hopf bifurcation and stability of bifurcating periodic solutions correspond to j ≠0 and j = 0, respectively. Finally, all these theoretical results are expected to be useful in the future study of dynamical complexity of ecological environment.
基金the National Natural Science Foundation of China(No.10271034)the Basic Research Foundation of Harbin Engineering University(No.HEUF04012)
文摘The initial boundary value problem of wave equations and reaction-diffusion equations with several nonlinear source terms in a bounded domain is studied by potential well method. The invarianee of some sets under the flow of these problems and the vacuum isolation of solutions are obtained by introducing a family of potential wells. Then the threshold result of global existence and nonexistence of solutions are given. Finally, the problem with critical initial conditions are discussed.
