Traveling wave solutions have been well studied for various nonlinear systems.However,for high order nonlinear physical models,there still exist various open problems.Here,travelling wave solutions to the well-known f...Traveling wave solutions have been well studied for various nonlinear systems.However,for high order nonlinear physical models,there still exist various open problems.Here,travelling wave solutions to the well-known fifth-order nonlinear physical model,the Sawada–Kotera equation,are revisited.Abundant travelling wave structures including soliton molecules,soliton lattice,kink-antikink molecules,peak-plateau soliton molecules,few-cycle-pulse solitons,double-peaked and triple-peaked solitons are unearthed.展开更多
Along with the globalization,all fields in the society are making a very broad,profound epochal change.Globalization has developed its own outstanding cultural characteristics in the development,and simultaneously the...Along with the globalization,all fields in the society are making a very broad,profound epochal change.Globalization has developed its own outstanding cultural characteristics in the development,and simultaneously the social and cultural influences from the era of globalization are also very significant.Because of globalization,the conflict between Chinese and western cultures widely emerge,which has been reflected obviously from different levels.Thus,it is imperative to adjust Chinese and western cultures in the process of globalization.展开更多
Invariant subspace method is exploited to obtain exact solutions of the two- component b-family system. It is shown that the two-component b-family system admits the generalized functional separable solutions. Further...Invariant subspace method is exploited to obtain exact solutions of the two- component b-family system. It is shown that the two-component b-family system admits the generalized functional separable solutions. Furthermore, blow up and behavior of those exact solutions are also investigated.展开更多
With the development of China's economy,the improvement of international influence,the adoption of"Belt and Road"strategy and the continuous development of foreign exchanges,the demand for intercultural ...With the development of China's economy,the improvement of international influence,the adoption of"Belt and Road"strategy and the continuous development of foreign exchanges,the demand for intercultural communication is increasing with the growth of international interaction. Chinese people are the main force of international communication in the future and we will shoulder the important duty of spreading Chinese culture. So it is very important to cultivate people's competence of intercultural communication. The competence refers to not only the language itself but also the bilateral cultures. The paper firstly implies the significance of intercultural awareness under the background of"Belt and Road"strategy. The second part is related to the literature reviewof intercultural communication. And it goes to the achievements of "Belt and Road"and the strategies of cultivating intercultural consciousness. According to the research,one point should be clear,that is,the cultivation of cultural consciousness is very important in intercultural communication in the progress of"Belt and Road".展开更多
Due to the influence and control of many factors such as geographical location and historical conditions,many of the 20thCentury American literature works portray distorted Chinese image different from reality. In Ame...Due to the influence and control of many factors such as geographical location and historical conditions,many of the 20thCentury American literature works portray distorted Chinese image different from reality. In American literature,China doesn't exist as a real country with a geographical location,but it exists in a virtual space in the world composed of cultural imagination. Literature is the reflected thought that can accommodate numerous social fields,and American literature can mostly reflect the overall cognition of different fields for Chinese image. This paper analyzes the characterization and cognition of Chinese image in the20thCentury American literature works,understanding the history and features of Chinese image in the 20thCentury American literature works,in order to obtain the enlightenment of how to better establish Chinese image.展开更多
In this paper, the continuity of consequence operators is introduced. Relations between consequence operators and their associated information algebras are mainly explored. It is shown that, for any given consequence ...In this paper, the continuity of consequence operators is introduced. Relations between consequence operators and their associated information algebras are mainly explored. It is shown that, for any given consequence operator, the associated information algebra can be directly constructed without any additional conditions.Furthermore, if the consequence operators are continous or compact, then the associated information algebras are continuous or compact.展开更多
In this paper, a novel adaptive control approach is presented to simultaneously achieve synchronization and antisynchronization in partially linear chaotic systems. Through appropriately separating state vectors of su...In this paper, a novel adaptive control approach is presented to simultaneously achieve synchronization and antisynchronization in partially linear chaotic systems. Through appropriately separating state vectors of such systems, synchronization and anti-synchronization could be simultaneously realized in different subspaces, which may be strictly proven theoretically. Simulation results for a Lorenz chaotic system and a new hyper-chaotic system are provided to illustrate the effectiveness of the proposed method. Finally, a new secure communication scheme based on such a synchronization phenomenon of the hyper-chaotic system is demonstrated. Numerical results show success in transmitting a periodic signal with high security.展开更多
In 2012, China National Ministry of Education issued a new undergraduate course catalog, economic statistics to be classified as a second level discipline of applied economics. However, what specific content should be...In 2012, China National Ministry of Education issued a new undergraduate course catalog, economic statistics to be classified as a second level discipline of applied economics. However, what specific content should be included in the second level discipline has become a very important issue. What should be taught to students or how can they adapt to the needs of the social market aroused a wide attention. For this case, the National Ministry of Education has given a clearly provision for economic statistics＇ core courses, but whether these main courses can reflect the actual needs and characteristics of economic statistics or not still needs some considerations and discussions. This article started from the angle of the studies on China and the U.S. Journals concerning economic statistics. Using text mining by R, a recent mainstream statistical analysis software, gives a comparative analysis on the contents of economic statistics for recent decades. We created wordcloud about the contents of core statistical journals by R which can help us visually examine the course of economic statistics discipline development for the comparative study. Besides, we drew a conclusion that there were significant differences between China and America＇s economic statistics, the main difference is the United States pay more attention to the exploration of new methods and be able to adapt to market demand, the development of China＇s economic statistics are still more traditional, it need a better understanding of the multi-disciplinary knowledge of education, such as Bayesian and dynamics. Another is that the curriculum of China＇s economic statistics are corrected for China＇s actual situation, a new training program pay more attention to students＇ practical ability and social practice. There are a lot of practical problems remain untouched or unsolved which need efforts of decades probably.展开更多
Based on the national strategy of"new urbanization",from the perspective of urban and rural integration,industrial interaction,economy and intensification,this paper proposes to vigorously promote the indust...Based on the national strategy of"new urbanization",from the perspective of urban and rural integration,industrial interaction,economy and intensification,this paper proposes to vigorously promote the industrialization planning of urban and rural housing based on SI system,do a good job in the production of building structural parts from the perspective of building industrialization,extend to the internal filling parts,and do a good job in the internal filling system from the perspective of housing industrialization.At the moment of"Rural Revitalization"strategy,we should first develop the SI system multi-storey industrialized housing to meet the needs of rural areas.At the same time,we put forward the development path of China's urban and rural housing industrialization.展开更多
Consider the system of integral equations with weighted functions in Rn,{u(x) =∫Rn|x-y|α-nQ(y)v(y)qdy1,v(x)=∫Rn|x-y|α-nK(y)u(y)pdy,where 0 < α < n,1/(p+1) + 1/(q+1)≥(n-α)/n1,α/(n-α) < p1q < ∞1,Q(...Consider the system of integral equations with weighted functions in Rn,{u(x) =∫Rn|x-y|α-nQ(y)v(y)qdy1,v(x)=∫Rn|x-y|α-nK(y)u(y)pdy,where 0 < α < n,1/(p+1) + 1/(q+1)≥(n-α)/n1,α/(n-α) < p1q < ∞1,Q(x) and K(x) satisfy some suitable conditions.It is shown that every positive regular solution(u(x)1,v(x)) is symmetric about some plane by developing the moving plane method in an integral form.Moreover,regularity of the solution is studied.Finally,the nonexistence of positive solutions to the system in the case 0 < p1q <(n+α)/(n-α) is also discussed.展开更多
Motivated by the widely used ans¨atz method and starting from the modified Riemann–Liouville derivative together with a fractional complex transformation that can be utilized to transform nonlinear fractional pa...Motivated by the widely used ans¨atz method and starting from the modified Riemann–Liouville derivative together with a fractional complex transformation that can be utilized to transform nonlinear fractional partial differential equations to nonlinear ordinary differential equations, new types of exact traveling wave solutions to three important nonlinear space- and time-fractional partial differential equations are obtained simultaneously in terms of solutions of a Riccati equation. The results are new and first reported in this paper.展开更多
The two-component μ-Camassa-Holm equation, the μ-Camassa-Holm equation and the modified μ- Camassa-Holm equation are three nonlocal integrable models. In this paper, it is shown that the two-component μ-Camassa-Ho...The two-component μ-Camassa-Holm equation, the μ-Camassa-Holm equation and the modified μ- Camassa-Holm equation are three nonlocal integrable models. In this paper, it is shown that the two-component μ-Camassa-Holm equation and the μ-Camassa-Holm equation with a linear dispersion admit a kind of nonlocal symmetries, and the modified μ-Camassa-Holm equation does not have such kind of nonlocal symmetry. An number of conservation laws to the modified μ-Camassa-Holm equation and μ-Camassa-Holm equation are obtained.展开更多
Two new 24-hydroxylated asterosaponins, sodium （20R,24S）-6α-O-（4-O-sodiumsulfato-β-D-quinovopyranosyl）-5α-cholest- 9（11）-en-3β,24-diol 3-sulfate （1） and sodium （20R,24S）-6α-O-β-O-methyl-β-D-quinovopyr...Two new 24-hydroxylated asterosaponins, sodium （20R,24S）-6α-O-（4-O-sodiumsulfato-β-D-quinovopyranosyl）-5α-cholest- 9（11）-en-3β,24-diol 3-sulfate （1） and sodium （20R,24S）-6α-O-β-O-methyl-β-D-quinovopyranosyl-（1→2）-β-D-xylopyranosyl- （1 → 3）-[3-D-glucopyranosyl]-5α-cholest-9（11）-en-3β,24-diol 3-sulfate （2）, were isolated from the starfish Culcita novaeguineae. Their structures were elucidated by extensive spectral analysis and chemical evidences.展开更多
Channel capacity is the prerequisite and basis for the design of a communication system.To assess the impact of a harsh plasma environment on the communication system of reentry vehicles,Shannon＇s information theory ...Channel capacity is the prerequisite and basis for the design of a communication system.To assess the impact of a harsh plasma environment on the communication system of reentry vehicles,Shannon＇s information theory is used to evaluate the channel capacity through the estimation results of the signal-to-noise ratio obtained by the communication link budget method.First,the attenuation caused by the plasma sheath is calculated with a stratified medium finite-difference time-domain method for typical S,C and Ka telemetry frequencies in a typical reentry plasma environment.Thereafter,typical telemetry transceiver parameters are considered to estimate the channel capacity.Results show that the S-band channel capacity is almost zero at the altitude of 30-40 km and the plasma attenuation at the C-band is slightly better.However,the blackout phenomenon remains obvious.The Ka-band signal can penetrate the plasma sheath layer with the smallest attenuation,thus significantly increasing the capacity of the channel and it may thus adequately meet telemetry needs.展开更多
We discuss the properties of solutions for the following elliptic partial differential equations system in Rn,where 0 〈α〈 n, pi and qi （i = 1, 2） satisfy some suitable assumptions. Due to equivalence between the ...We discuss the properties of solutions for the following elliptic partial differential equations system in Rn,where 0 〈α〈 n, pi and qi （i = 1, 2） satisfy some suitable assumptions. Due to equivalence between the PDEs system and a given integral system, we prove the radial symmetry and regularity of positive solutions to the PDEs system via the method of moving plane in integral forms and Regularity Lifting Lemma. For the special case, when p1 ＋ p2= q1 ＋ q2 = n＋α/n-α, we classify the solutions of the PDEs system.展开更多
This study uses the global pollutant emission databases and global input-output model in 2015 to calculate the impact of international trade on global water nitrogen emission patterns,based on considering the total am...This study uses the global pollutant emission databases and global input-output model in 2015 to calculate the impact of international trade on global water nitrogen emission patterns,based on considering the total amount of pollutant transfer and pollutant emission intensity of trade flows The main conclusions are as follows:(1) There are always a large amount of water nitrogen emissions transferring from developed economies to developing economies embodied in their bilateral trade activities.Small amount of transfers are of some areas with similar endowments of agricultural resources or long distances.(2) In 2015,the net import of water nitrogen pollution embodied in China's trade was 160,000 tons,accounting for 2.72% of the global water nitrogen imports.The sharp increases in cereal imports,together with high food storage as well as high pollution intensity embedded in trade are the main reason.It is recommended that through applying alleviations such as agricultural machinery assistance and technical training to accelerate the transfer and spread of agricultural technology in Africa,Asia,and other regions,thus helping increase agricultural production productivity in underdeveloped areas and reducing the pollution intensity embodied in trade flows from underdeveloped areas to developed areas.展开更多
Consider the system with three-component integral equations{u（x） ：fRn│x - y│α-nw（y）^v（y）^qdy,v（x） =fRn│x-y│^α-nu（y）^pw（y）^rdy, w（x） =fRn│x - y│α-nv（y）qu（y）Pdy,where 0 〈 a 〈 n, n is a posi...Consider the system with three-component integral equations{u（x） ：fRn│x - y│α-nw（y）^v（y）^qdy,v（x） =fRn│x-y│^α-nu（y）^pw（y）^rdy, w（x） =fRn│x - y│α-nv（y）qu（y）Pdy,where 0 〈 a 〈 n, n is a positive constant, p, q and r satisfy some suitable conditions. It is shown that every positive regular solution （u（x）, v（x）, w（x）） is radially symmetric and monotonic about some point by developing the moving plane method in an integral form. In addition, the regularity of the solutions is also proved by the contraction mapping principle. The conformal invariant property of the system is also investigated.展开更多
A novel genetic algorithm with multiple species in dynamic region is proposed,each of which occupies a dynamic region determined by the weight vector of a fuzzy adaptive Hamming neural network. Through learning and cl...A novel genetic algorithm with multiple species in dynamic region is proposed,each of which occupies a dynamic region determined by the weight vector of a fuzzy adaptive Hamming neural network. Through learning and classification of genetic individuals in the evolutionary procedure,the neural network distributes multiple species into different regions of the search space. Furthermore,the neural network dynamically expands each search region or establishes new region for good offspring individuals to continuously keep the diversification of the genetic population. As a result,the premature problem inherent in genetic algorithm is alleviated and better tradeoff between the ability of exploration and exploitation can be obtained. The experimental results on the vehicle routing problem with time windows also show the good performance of the proposed genetic algorithm.展开更多
This paper investigates the asymptotic behavior of tail probability of randomly weighted sums of dependent and real-valued random variables with dominated variation, where the weights form another sequence of nonnegat...This paper investigates the asymptotic behavior of tail probability of randomly weighted sums of dependent and real-valued random variables with dominated variation, where the weights form another sequence of nonnegative random variables. The result we obtain extends the corresponding result of Wang and Tang.展开更多
基金Supported by the National Natural Science Foundation of China(Grant Nos.11975131, 11435005 and 11471004)K.C.Wong Magna Fund in Ningbo University
文摘Traveling wave solutions have been well studied for various nonlinear systems.However,for high order nonlinear physical models,there still exist various open problems.Here,travelling wave solutions to the well-known fifth-order nonlinear physical model,the Sawada–Kotera equation,are revisited.Abundant travelling wave structures including soliton molecules,soliton lattice,kink-antikink molecules,peak-plateau soliton molecules,few-cycle-pulse solitons,double-peaked and triple-peaked solitons are unearthed.
文摘Along with the globalization,all fields in the society are making a very broad,profound epochal change.Globalization has developed its own outstanding cultural characteristics in the development,and simultaneously the social and cultural influences from the era of globalization are also very significant.Because of globalization,the conflict between Chinese and western cultures widely emerge,which has been reflected obviously from different levels.Thus,it is imperative to adjust Chinese and western cultures in the process of globalization.
基金supported by NSFC(11471260)the Foundation of Shannxi Education Committee(12JK0850)
文摘Invariant subspace method is exploited to obtain exact solutions of the two- component b-family system. It is shown that the two-component b-family system admits the generalized functional separable solutions. Furthermore, blow up and behavior of those exact solutions are also investigated.
基金supported by the research of Shaanxi philosophy and social science planning office(Grant NO.2018J17)the Research Foundation of Shaanxi provincial department of education(Grant NO.16JK1293)
文摘With the development of China's economy,the improvement of international influence,the adoption of"Belt and Road"strategy and the continuous development of foreign exchanges,the demand for intercultural communication is increasing with the growth of international interaction. Chinese people are the main force of international communication in the future and we will shoulder the important duty of spreading Chinese culture. So it is very important to cultivate people's competence of intercultural communication. The competence refers to not only the language itself but also the bilateral cultures. The paper firstly implies the significance of intercultural awareness under the background of"Belt and Road"strategy. The second part is related to the literature reviewof intercultural communication. And it goes to the achievements of "Belt and Road"and the strategies of cultivating intercultural consciousness. According to the research,one point should be clear,that is,the cultivation of cultural consciousness is very important in intercultural communication in the progress of"Belt and Road".
文摘Due to the influence and control of many factors such as geographical location and historical conditions,many of the 20thCentury American literature works portray distorted Chinese image different from reality. In American literature,China doesn't exist as a real country with a geographical location,but it exists in a virtual space in the world composed of cultural imagination. Literature is the reflected thought that can accommodate numerous social fields,and American literature can mostly reflect the overall cognition of different fields for Chinese image. This paper analyzes the characterization and cognition of Chinese image in the20thCentury American literature works,understanding the history and features of Chinese image in the 20thCentury American literature works,in order to obtain the enlightenment of how to better establish Chinese image.
基金The NSF(61702389) of ChinaScientific Research Program Fund(18JK0315) of Shaanxi Provincial Education Department
文摘In this paper, the continuity of consequence operators is introduced. Relations between consequence operators and their associated information algebras are mainly explored. It is shown that, for any given consequence operator, the associated information algebra can be directly constructed without any additional conditions.Furthermore, if the consequence operators are continous or compact, then the associated information algebras are continuous or compact.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60804021)
文摘In this paper, a novel adaptive control approach is presented to simultaneously achieve synchronization and antisynchronization in partially linear chaotic systems. Through appropriately separating state vectors of such systems, synchronization and anti-synchronization could be simultaneously realized in different subspaces, which may be strictly proven theoretically. Simulation results for a Lorenz chaotic system and a new hyper-chaotic system are provided to illustrate the effectiveness of the proposed method. Finally, a new secure communication scheme based on such a synchronization phenomenon of the hyper-chaotic system is demonstrated. Numerical results show success in transmitting a periodic signal with high security.
文摘In 2012, China National Ministry of Education issued a new undergraduate course catalog, economic statistics to be classified as a second level discipline of applied economics. However, what specific content should be included in the second level discipline has become a very important issue. What should be taught to students or how can they adapt to the needs of the social market aroused a wide attention. For this case, the National Ministry of Education has given a clearly provision for economic statistics＇ core courses, but whether these main courses can reflect the actual needs and characteristics of economic statistics or not still needs some considerations and discussions. This article started from the angle of the studies on China and the U.S. Journals concerning economic statistics. Using text mining by R, a recent mainstream statistical analysis software, gives a comparative analysis on the contents of economic statistics for recent decades. We created wordcloud about the contents of core statistical journals by R which can help us visually examine the course of economic statistics discipline development for the comparative study. Besides, we drew a conclusion that there were significant differences between China and America＇s economic statistics, the main difference is the United States pay more attention to the exploration of new methods and be able to adapt to market demand, the development of China＇s economic statistics are still more traditional, it need a better understanding of the multi-disciplinary knowledge of education, such as Bayesian and dynamics. Another is that the curriculum of China＇s economic statistics are corrected for China＇s actual situation, a new training program pay more attention to students＇ practical ability and social practice. There are a lot of practical problems remain untouched or unsolved which need efforts of decades probably.
基金On March 15,2021,supported by the 2019 soft science project of Shaanxi Provincial Science and Technology Department,research on the development path and countermeasures of Shaanxi urban and rural housing industrialization(Project No.:2019krm037).
文摘Based on the national strategy of"new urbanization",from the perspective of urban and rural integration,industrial interaction,economy and intensification,this paper proposes to vigorously promote the industrialization planning of urban and rural housing based on SI system,do a good job in the production of building structural parts from the perspective of building industrialization,extend to the internal filling parts,and do a good job in the internal filling system from the perspective of housing industrialization.At the moment of"Rural Revitalization"strategy,we should first develop the SI system multi-storey industrialized housing to meet the needs of rural areas.At the same time,we put forward the development path of China's urban and rural housing industrialization.
基金supported by Chinese National Science Fund for Distinguished Young Scholars (Grant No.10925104)National Natural Science Foundation of China (Grant No.11001221)+1 种基金the Foundation of Shaanxi Province Education Department (Grant No. 2010JK549)the Foundation of Xi’an Statistical Research Institute (Grant No.10JD04)
文摘Consider the system of integral equations with weighted functions in Rn,{u(x) =∫Rn|x-y|α-nQ(y)v(y)qdy1,v(x)=∫Rn|x-y|α-nK(y)u(y)pdy,where 0 < α < n,1/(p+1) + 1/(q+1)≥(n-α)/n1,α/(n-α) < p1q < ∞1,Q(x) and K(x) satisfy some suitable conditions.It is shown that every positive regular solution(u(x)1,v(x)) is symmetric about some plane by developing the moving plane method in an integral form.Moreover,regularity of the solution is studied.Finally,the nonexistence of positive solutions to the system in the case 0 < p1q <(n+α)/(n-α) is also discussed.
基金Supported by National Natural Science Foundation of China under Grant Nos.11071278,111471004the Fundamental Research Funds for the Central Universities of GK201302026 and GK201102007
文摘Motivated by the widely used ans¨atz method and starting from the modified Riemann–Liouville derivative together with a fractional complex transformation that can be utilized to transform nonlinear fractional partial differential equations to nonlinear ordinary differential equations, new types of exact traveling wave solutions to three important nonlinear space- and time-fractional partial differential equations are obtained simultaneously in terms of solutions of a Riccati equation. The results are new and first reported in this paper.
基金Shi is supported by the NSF of China under the grant 11471174Kang is partially supported by the NSF of China under the grant 11001220
文摘The two-component μ-Camassa-Holm equation, the μ-Camassa-Holm equation and the modified μ- Camassa-Holm equation are three nonlocal integrable models. In this paper, it is shown that the two-component μ-Camassa-Holm equation and the μ-Camassa-Holm equation with a linear dispersion admit a kind of nonlocal symmetries, and the modified μ-Camassa-Holm equation does not have such kind of nonlocal symmetry. An number of conservation laws to the modified μ-Camassa-Holm equation and μ-Camassa-Holm equation are obtained.
基金the National Nature Science Foundation of China(No.20502035)the National High-Tech Research and Development Project(No.2006AA09Z423)
文摘Two new 24-hydroxylated asterosaponins, sodium （20R,24S）-6α-O-（4-O-sodiumsulfato-β-D-quinovopyranosyl）-5α-cholest- 9（11）-en-3β,24-diol 3-sulfate （1） and sodium （20R,24S）-6α-O-β-O-methyl-β-D-quinovopyranosyl-（1→2）-β-D-xylopyranosyl- （1 → 3）-[3-D-glucopyranosyl]-5α-cholest-9（11）-en-3β,24-diol 3-sulfate （2）, were isolated from the starfish Culcita novaeguineae. Their structures were elucidated by extensive spectral analysis and chemical evidences.
基金supported by the National Program on Key Basic Research Project of China(No.2014CB340205)National Natural Science Foundation of China(Nos.61301173 and 61473228)
文摘Channel capacity is the prerequisite and basis for the design of a communication system.To assess the impact of a harsh plasma environment on the communication system of reentry vehicles,Shannon＇s information theory is used to evaluate the channel capacity through the estimation results of the signal-to-noise ratio obtained by the communication link budget method.First,the attenuation caused by the plasma sheath is calculated with a stratified medium finite-difference time-domain method for typical S,C and Ka telemetry frequencies in a typical reentry plasma environment.Thereafter,typical telemetry transceiver parameters are considered to estimate the channel capacity.Results show that the S-band channel capacity is almost zero at the altitude of 30-40 km and the plasma attenuation at the C-band is slightly better.However,the blackout phenomenon remains obvious.The Ka-band signal can penetrate the plasma sheath layer with the smallest attenuation,thus significantly increasing the capacity of the channel and it may thus adequately meet telemetry needs.
基金Supported by National Natural Science Foundation of China(Grant No.11571268)the foundation of Xi’an University of Finance and Economics(Grant No.12XCK07)
文摘We discuss the properties of solutions for the following elliptic partial differential equations system in Rn,where 0 〈α〈 n, pi and qi （i = 1, 2） satisfy some suitable assumptions. Due to equivalence between the PDEs system and a given integral system, we prove the radial symmetry and regularity of positive solutions to the PDEs system via the method of moving plane in integral forms and Regularity Lifting Lemma. For the special case, when p1 ＋ p2= q1 ＋ q2 = n＋α/n-α, we classify the solutions of the PDEs system.
基金Beijing Natural Science Foundation[Grant number:9154036]Special Fund for Talents of Science&Technology Innovation Engineering of Chinese Academy of Agricultural Sciences[Grant number:ASTIP-IAED-2019RC-01]The fundamental Research funds for the central research institutes(Grant number:161005201803-2).
文摘This study uses the global pollutant emission databases and global input-output model in 2015 to calculate the impact of international trade on global water nitrogen emission patterns,based on considering the total amount of pollutant transfer and pollutant emission intensity of trade flows The main conclusions are as follows:(1) There are always a large amount of water nitrogen emissions transferring from developed economies to developing economies embodied in their bilateral trade activities.Small amount of transfers are of some areas with similar endowments of agricultural resources or long distances.(2) In 2015,the net import of water nitrogen pollution embodied in China's trade was 160,000 tons,accounting for 2.72% of the global water nitrogen imports.The sharp increases in cereal imports,together with high food storage as well as high pollution intensity embedded in trade are the main reason.It is recommended that through applying alleviations such as agricultural machinery assistance and technical training to accelerate the transfer and spread of agricultural technology in Africa,Asia,and other regions,thus helping increase agricultural production productivity in underdeveloped areas and reducing the pollution intensity embodied in trade flows from underdeveloped areas to developed areas.
基金supported by National National Science Foundation of China for Distinguished Young Scholars (Grant No. 10925104)National National Science Foundation of China (Grant No.11101319)the Foundation of Shaanxi Province Education Department (Grant No. 2010JK549)
文摘Consider the system with three-component integral equations{u（x） ：fRn│x - y│α-nw（y）^v（y）^qdy,v（x） =fRn│x-y│^α-nu（y）^pw（y）^rdy, w（x） =fRn│x - y│α-nv（y）qu（y）Pdy,where 0 〈 a 〈 n, n is a positive constant, p, q and r satisfy some suitable conditions. It is shown that every positive regular solution （u（x）, v（x）, w（x）） is radially symmetric and monotonic about some point by developing the moving plane method in an integral form. In addition, the regularity of the solutions is also proved by the contraction mapping principle. The conformal invariant property of the system is also investigated.
文摘A novel genetic algorithm with multiple species in dynamic region is proposed,each of which occupies a dynamic region determined by the weight vector of a fuzzy adaptive Hamming neural network. Through learning and classification of genetic individuals in the evolutionary procedure,the neural network distributes multiple species into different regions of the search space. Furthermore,the neural network dynamically expands each search region or establishes new region for good offspring individuals to continuously keep the diversification of the genetic population. As a result,the premature problem inherent in genetic algorithm is alleviated and better tradeoff between the ability of exploration and exploitation can be obtained. The experimental results on the vehicle routing problem with time windows also show the good performance of the proposed genetic algorithm.
基金Supported by the National Natural Science Foundation of China(Grant No.10802061)the Research Project of Xi'an Institute of Statistics(Grant No.07JD16)
文摘This paper investigates the asymptotic behavior of tail probability of randomly weighted sums of dependent and real-valued random variables with dominated variation, where the weights form another sequence of nonnegative random variables. The result we obtain extends the corresponding result of Wang and Tang.
