Seismic finite-difference(FD) modeling suffers from numerical dispersion including both the temporal and spatial dispersion, which can decrease the accuracy of the numerical modeling. To improve the accuracy and effic...Seismic finite-difference(FD) modeling suffers from numerical dispersion including both the temporal and spatial dispersion, which can decrease the accuracy of the numerical modeling. To improve the accuracy and efficiency of the conventional numerical modeling, I develop a new seismic modeling method by combining the FD scheme with the numerical dispersion suppression neural network(NDSNN). This method involves the following steps. First, a training data set composed of a small number of wavefield snapshots is generated. The wavefield snapshots with the low-accuracy wavefield data and the high-accuracy wavefield data are paired, and the low-accuracy wavefield snapshots involve the obvious numerical dispersion including both the temporal and spatial dispersion. Second, the NDSNN is trained until the network converges to simultaneously suppress the temporal and spatial dispersion.Third, the entire set of low-accuracy wavefield data is computed quickly using FD modeling with the large time step and the coarse grid. Fourth, the NDSNN is applied to the entire set of low-accuracy wavefield data to suppress the numerical dispersion including the temporal and spatial dispersion.Numerical modeling examples verify the effectiveness of my proposed method in improving the computational accuracy and efficiency.展开更多
This paper establishes several new Lyapunov-type inequalities for the system of nonlinear difference equations■,which extend/supplement and improve some related existing ones.
A new conservative finite difference scheme is presented based on the numerical analysis for an initialboundary value problem of a class of Schroedinger equation with the wave operator. The scheme can be linear and im...A new conservative finite difference scheme is presented based on the numerical analysis for an initialboundary value problem of a class of Schroedinger equation with the wave operator. The scheme can be linear and implicit or explicit based on the parameter choice. The initial value after discretization has second-order accuracy that is consistent with the scheme accuracy. The existence and the uniqueness of the difference solution are proved. Based on the priori estimates and an inequality about norms, the stability and the convergence of difference solutions with the second-order are proved in the energy norm. Experimental results demonstrate the efficiency of the new scheme.展开更多
In this paper,a implicit difference scheme is proposed for solving the equation of one_dimension parabolic type by undetermined paameters.The stability condition is r=αΔt/Δx 2 1/2 and the truncation error is o(...In this paper,a implicit difference scheme is proposed for solving the equation of one_dimension parabolic type by undetermined paameters.The stability condition is r=αΔt/Δx 2 1/2 and the truncation error is o(Δt 4+Δx 4) It can be easily solved by double sweeping method.展开更多
This paper presents an explicit difference scheme with accuracy and branching stability for solving onedimensional parabolic type equation by the method of undetermined parameters and its truncation error is O(△t4+△...This paper presents an explicit difference scheme with accuracy and branching stability for solving onedimensional parabolic type equation by the method of undetermined parameters and its truncation error is O(△t4+△x4). The stability condition is r=a△t/△x2<1/2.展开更多
A family of high_order accuracy explicit difference schemes for solving 2_dimension parabolic P.D.E. are constructed. Th e stability condition is r=Δt/Δx 2=Δt/Δy 2【1/2 and the truncation err or is O(Δt 3+Δx...A family of high_order accuracy explicit difference schemes for solving 2_dimension parabolic P.D.E. are constructed. Th e stability condition is r=Δt/Δx 2=Δt/Δy 2【1/2 and the truncation err or is O(Δt 3+Δx 4).展开更多
There is an apparent contrast between children’s first language acquisition and adults’second language acquisition,which are mainly manifested in the following three aspects:age difference,difference in learning pro...There is an apparent contrast between children’s first language acquisition and adults’second language acquisition,which are mainly manifested in the following three aspects:age difference,difference in learning process and motivation difference.This paper will analyze these three differences in detail,and combine the analysis results to guide second language pedagogical implications according to the current situation.展开更多
To deduce a new color difference formula based on CIE 1997 Color Appearance Model(CIECAM97s), a color space J a 1 b 1 is first constructed with color appearance descriptors J,a,b in CIECAM97s. The new f...To deduce a new color difference formula based on CIE 1997 Color Appearance Model(CIECAM97s), a color space J a 1 b 1 is first constructed with color appearance descriptors J,a,b in CIECAM97s. The new formula is then deduced in the space and named CDF CIECAM97s. The factors for lightness, chroma and hue correction in the formula are derived by linear regression according to BFD? CP data sets. It is found by statistical analysis that CDF CIECAM97s is in closer accordance with the visual assessments when compared with CMC(1∶1), CIE94 and CIE L *a *b * color difference formulae. Based on color appearance model, the new color difference formula can be used to predict color difference perception in a varity of different viewing conditions.展开更多
In this article, the existence of finite order entire solutions of nonlinear difference equations fn+ Pd(z, f) = p1 eα1 z+ p2 eα2 z are studied, where n ≥ 2 is an integer, Pd(z, f) is a difference polynomial ...In this article, the existence of finite order entire solutions of nonlinear difference equations fn+ Pd(z, f) = p1 eα1 z+ p2 eα2 z are studied, where n ≥ 2 is an integer, Pd(z, f) is a difference polynomial in f of degree d(≤ n-2), p1, p2 are small meromorphic functions of ez, and α1, α2 are nonzero constants. Some necessary conditions are given to guarantee that the above equation has an entire solution of finite order. As its applications, we also find some type of nonlinear difference equations having no finite order entire solutions.展开更多
Translation theories are based on the different languages and cultures.The difference is not clearly defined,so there is a place of mutual integration that can be used interchangeably.Theyall regard author’s meaning ...Translation theories are based on the different languages and cultures.The difference is not clearly defined,so there is a place of mutual integration that can be used interchangeably.Theyall regard author’s meaning and style as a core to translate a good product.Comparatively,Chinese theories focus on expressing the general meaning of the author,but Western theory emphasizes equivalence of details on translation and response of reader.In the translation practice,according to different theoretical texts and different stages of the translation process,the Chinese and Western translation theories are combined to apply them for making up for each other's deficiencies,which can help our translators to solve the problems in the process of translation improve the construction of Chinese theories.展开更多
Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjectur...Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjecture forward.展开更多
A class of high resolution positivity preserving Boltzmann type difference schemes for one and two dimensional Euler equations is studied. First, the relation between Boltzmann and Euler equations is analyzed. By usi...A class of high resolution positivity preserving Boltzmann type difference schemes for one and two dimensional Euler equations is studied. First, the relation between Boltzmann and Euler equations is analyzed. By using a kind of special interpolation, the high resolution Boltzmann type difference scheme is constructed. Finally, numerical tests show that the schemes are effective and useful.展开更多
In this paper, the authors establish some theorems that can ascertain the zero solutions of systemsx(n+1)=f(n,x n)(1)are uniformly stable,asymptotically stable or uniformly asymptotically stable. In the obtained theo...In this paper, the authors establish some theorems that can ascertain the zero solutions of systemsx(n+1)=f(n,x n)(1)are uniformly stable,asymptotically stable or uniformly asymptotically stable. In the obtained theorems, ΔV is not required to be always negative, where ΔV(n,x n)≡V(n+1,x(n+1)) -V(n,x(n))=V(n+1,f(n,x n))-V(n,x(n)), especially, in Theorem 1, ΔV may be even positive, which greatly improve the known results and are more convenient to use.展开更多
When translating the titles of films,translators are faced with not only different meanings of Chinese and English language,but also various cultural connotations behind the titles.Therefore,translators should take cu...When translating the titles of films,translators are faced with not only different meanings of Chinese and English language,but also various cultural connotations behind the titles.Therefore,translators should take cultural differences into account in order to make the translated titles close to the connotations of the source culture.Such cultural differences as religious dissimilarities,historical allusions and idiomatic expressions(or idioms)are major concerns when translating film titles.展开更多
Aim To obtain new criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations. Methods By means of Hlder inequality and a method of direct analysis, some i...Aim To obtain new criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations. Methods By means of Hlder inequality and a method of direct analysis, some interesting Lemmas were offered. Results and Conclusion New criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations are established, which extend and improve the results obtained in the literature. Some interesting examples illustrating the importance of our results are also included.展开更多
Values are the most important issue in identifying one particular culture.Social values are the feelings people have about what is important,worthwhile,and just.In this paper,the differences between British and Americ...Values are the most important issue in identifying one particular culture.Social values are the feelings people have about what is important,worthwhile,and just.In this paper,the differences between British and American values are discussed in two aspects which mainly lie respectively in the comparisons of values and characteristics in both cultures.展开更多
In both English and Chinese, pronouns are used with great frequency. And there are numerous usages of pronoun anaphors. The similarities and differences are summarized with the comparison of pronoun anaphors in Englis...In both English and Chinese, pronouns are used with great frequency. And there are numerous usages of pronoun anaphors. The similarities and differences are summarized with the comparison of pronoun anaphors in English and Chinese.展开更多
Translation is an activity aimed at transferring the source language to the target language,related to many aspects involving culture,society,history and so on.The translator plays a critical role in translation pract...Translation is an activity aimed at transferring the source language to the target language,related to many aspects involving culture,society,history and so on.The translator plays a critical role in translation practice.Xu Jun considers"translator’s subjectivity should be reflected to be artistic personal consciousness in translated works."Translator’s differences in age,gender,personal traits,educational level and other aspects make translation artistry completely divergent.Therefore,translator’s subjectivity shoulders great significances on the success of literary translation,which isn’t arbitrary,out of control,must be conducted in line with essence of the original work.This paper focuses on the gender difference of translator’s subjectivity in literary translation,hoping to find a way of eliminating the influence of it in the translation work.展开更多
The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under differe...The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under different conditions. We find that like product difference, cost difference have important influence on the choice of channel structure. This paper has improved the present result and provided proof for the choice of channel structure under different environments.展开更多
For years,there has been a considerable interest in linguistic differentiation associated with the speaker’s gender.Based on the researches and investigations of many linguists,this paper examines the linguistic gend...For years,there has been a considerable interest in linguistic differentiation associated with the speaker’s gender.Based on the researches and investigations of many linguists,this paper examines the linguistic gender differences from the following respects:gender difference in phonology,gender difference in lexicon,gender difference in syntax and gender differences in pragmatics.The awareness of these linguistic differences between different genders can facilitate people’s communication in their daily lives.展开更多
基金supported by the National Natural Science Foundation of China (grant numbers: 41874160 and 92055213)。
文摘Seismic finite-difference(FD) modeling suffers from numerical dispersion including both the temporal and spatial dispersion, which can decrease the accuracy of the numerical modeling. To improve the accuracy and efficiency of the conventional numerical modeling, I develop a new seismic modeling method by combining the FD scheme with the numerical dispersion suppression neural network(NDSNN). This method involves the following steps. First, a training data set composed of a small number of wavefield snapshots is generated. The wavefield snapshots with the low-accuracy wavefield data and the high-accuracy wavefield data are paired, and the low-accuracy wavefield snapshots involve the obvious numerical dispersion including both the temporal and spatial dispersion. Second, the NDSNN is trained until the network converges to simultaneously suppress the temporal and spatial dispersion.Third, the entire set of low-accuracy wavefield data is computed quickly using FD modeling with the large time step and the coarse grid. Fourth, the NDSNN is applied to the entire set of low-accuracy wavefield data to suppress the numerical dispersion including the temporal and spatial dispersion.Numerical modeling examples verify the effectiveness of my proposed method in improving the computational accuracy and efficiency.
基金supported by the NNSF of China(Grant No.41405083)Hunan Provincial Natural Science Foundation of China(Grant No.2015JJ3098)
文摘This paper establishes several new Lyapunov-type inequalities for the system of nonlinear difference equations■,which extend/supplement and improve some related existing ones.
文摘A new conservative finite difference scheme is presented based on the numerical analysis for an initialboundary value problem of a class of Schroedinger equation with the wave operator. The scheme can be linear and implicit or explicit based on the parameter choice. The initial value after discretization has second-order accuracy that is consistent with the scheme accuracy. The existence and the uniqueness of the difference solution are proved. Based on the priori estimates and an inequality about norms, the stability and the convergence of difference solutions with the second-order are proved in the energy norm. Experimental results demonstrate the efficiency of the new scheme.
文摘In this paper,a implicit difference scheme is proposed for solving the equation of one_dimension parabolic type by undetermined paameters.The stability condition is r=αΔt/Δx 2 1/2 and the truncation error is o(Δt 4+Δx 4) It can be easily solved by double sweeping method.
文摘This paper presents an explicit difference scheme with accuracy and branching stability for solving onedimensional parabolic type equation by the method of undetermined parameters and its truncation error is O(△t4+△x4). The stability condition is r=a△t/△x2<1/2.
文摘A family of high_order accuracy explicit difference schemes for solving 2_dimension parabolic P.D.E. are constructed. Th e stability condition is r=Δt/Δx 2=Δt/Δy 2【1/2 and the truncation err or is O(Δt 3+Δx 4).
文摘There is an apparent contrast between children’s first language acquisition and adults’second language acquisition,which are mainly manifested in the following three aspects:age difference,difference in learning process and motivation difference.This paper will analyze these three differences in detail,and combine the analysis results to guide second language pedagogical implications according to the current situation.
文摘To deduce a new color difference formula based on CIE 1997 Color Appearance Model(CIECAM97s), a color space J a 1 b 1 is first constructed with color appearance descriptors J,a,b in CIECAM97s. The new formula is then deduced in the space and named CDF CIECAM97s. The factors for lightness, chroma and hue correction in the formula are derived by linear regression according to BFD? CP data sets. It is found by statistical analysis that CDF CIECAM97s is in closer accordance with the visual assessments when compared with CMC(1∶1), CIE94 and CIE L *a *b * color difference formulae. Based on color appearance model, the new color difference formula can be used to predict color difference perception in a varity of different viewing conditions.
基金supported by the National Natural Science Foundation of China(11661044)
文摘In this article, the existence of finite order entire solutions of nonlinear difference equations fn+ Pd(z, f) = p1 eα1 z+ p2 eα2 z are studied, where n ≥ 2 is an integer, Pd(z, f) is a difference polynomial in f of degree d(≤ n-2), p1, p2 are small meromorphic functions of ez, and α1, α2 are nonzero constants. Some necessary conditions are given to guarantee that the above equation has an entire solution of finite order. As its applications, we also find some type of nonlinear difference equations having no finite order entire solutions.
文摘Translation theories are based on the different languages and cultures.The difference is not clearly defined,so there is a place of mutual integration that can be used interchangeably.Theyall regard author’s meaning and style as a core to translate a good product.Comparatively,Chinese theories focus on expressing the general meaning of the author,but Western theory emphasizes equivalence of details on translation and response of reader.In the translation practice,according to different theoretical texts and different stages of the translation process,the Chinese and Western translation theories are combined to apply them for making up for each other's deficiencies,which can help our translators to solve the problems in the process of translation improve the construction of Chinese theories.
文摘Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjecture forward.
文摘A class of high resolution positivity preserving Boltzmann type difference schemes for one and two dimensional Euler equations is studied. First, the relation between Boltzmann and Euler equations is analyzed. By using a kind of special interpolation, the high resolution Boltzmann type difference scheme is constructed. Finally, numerical tests show that the schemes are effective and useful.
文摘In this paper, the authors establish some theorems that can ascertain the zero solutions of systemsx(n+1)=f(n,x n)(1)are uniformly stable,asymptotically stable or uniformly asymptotically stable. In the obtained theorems, ΔV is not required to be always negative, where ΔV(n,x n)≡V(n+1,x(n+1)) -V(n,x(n))=V(n+1,f(n,x n))-V(n,x(n)), especially, in Theorem 1, ΔV may be even positive, which greatly improve the known results and are more convenient to use.
文摘When translating the titles of films,translators are faced with not only different meanings of Chinese and English language,but also various cultural connotations behind the titles.Therefore,translators should take cultural differences into account in order to make the translated titles close to the connotations of the source culture.Such cultural differences as religious dissimilarities,historical allusions and idiomatic expressions(or idioms)are major concerns when translating film titles.
文摘Aim To obtain new criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations. Methods By means of Hlder inequality and a method of direct analysis, some interesting Lemmas were offered. Results and Conclusion New criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations are established, which extend and improve the results obtained in the literature. Some interesting examples illustrating the importance of our results are also included.
文摘Values are the most important issue in identifying one particular culture.Social values are the feelings people have about what is important,worthwhile,and just.In this paper,the differences between British and American values are discussed in two aspects which mainly lie respectively in the comparisons of values and characteristics in both cultures.
文摘In both English and Chinese, pronouns are used with great frequency. And there are numerous usages of pronoun anaphors. The similarities and differences are summarized with the comparison of pronoun anaphors in English and Chinese.
文摘Translation is an activity aimed at transferring the source language to the target language,related to many aspects involving culture,society,history and so on.The translator plays a critical role in translation practice.Xu Jun considers"translator’s subjectivity should be reflected to be artistic personal consciousness in translated works."Translator’s differences in age,gender,personal traits,educational level and other aspects make translation artistry completely divergent.Therefore,translator’s subjectivity shoulders great significances on the success of literary translation,which isn’t arbitrary,out of control,must be conducted in line with essence of the original work.This paper focuses on the gender difference of translator’s subjectivity in literary translation,hoping to find a way of eliminating the influence of it in the translation work.
基金Supported by the National Preeminence Youth Foundation of China(No.79275002)
文摘The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under different conditions. We find that like product difference, cost difference have important influence on the choice of channel structure. This paper has improved the present result and provided proof for the choice of channel structure under different environments.
文摘For years,there has been a considerable interest in linguistic differentiation associated with the speaker’s gender.Based on the researches and investigations of many linguists,this paper examines the linguistic gender differences from the following respects:gender difference in phonology,gender difference in lexicon,gender difference in syntax and gender differences in pragmatics.The awareness of these linguistic differences between different genders can facilitate people’s communication in their daily lives.