The Honghe Hani Rice Terraces of Yunnan Province have become a national emblem for China and a UNESCO World Heritage Site,but some are beginning to crumble.This research attempts to address why this is happening and w...The Honghe Hani Rice Terraces of Yunnan Province have become a national emblem for China and a UNESCO World Heritage Site,but some are beginning to crumble.This research attempts to address why this is happening and what can be done about it.Previous work has failed to adequately address the possible shortcomings of recently introduced seed and water management technologies,their particular effect on rice terraces and the people who depend upon them.In an effort to better understand the issue,field observation was triangulated with in-depth interviews with local people,and the examination of scientific literature.To do this,the authors spent time in China with a translator in a key village known to be first in the area to truly succeed in carving the rice terraces and in making the mountain slope irrigation system required actually working.Results validated by experts in each field indicate that while the new seed and technologies do save water and improve lives,paired with migration,they may also be threatening the long-term viability of rice terracing in the region.The authors conclude that an integrated approach is needed and put forward a strategic blueprint to reinforce ecological,social and economic longevity.They also call for more research into the applicability of these resilience measures in other hybrid rice terracing regions,such as in the Philippines and Vietnam.展开更多
Zn-Al coatings can provide protection to exposed steel parts in most environments. For this reason, the investigation of Zn-Al coatings become very popular in recent years. In order to study the microstructures and pr...Zn-Al coatings can provide protection to exposed steel parts in most environments. For this reason, the investigation of Zn-Al coatings become very popular in recent years. In order to study the microstructures and properties of mechanically deposited Zn-Al coating, zinc powders and aluminum powders were used to deposit Zn-AI coating by mechanical plating. The microstruetures, phase constitutes and compositions of the coating were observed and analyzed with optical microscopy （OM）, scanning electron microscopy（SEM）, X-ray diffraction（XRD） and X-ray energy-dispersive spectroscopy（EDS）. The results of observation show that the coating consists of almost spherically shaped zinc particles point contacting with each other; the coatings are composed of zinc particles, aluminum particles, interstice, and tin; extra fine zinc powders and some smaller interspersed inclusions are positioned in the interstices. Porosity and thickness of the coating were tested by ferroxyl test and magnetic method. The corrosion resistance of coatings was studied by neutral salt spraying test（NSS）, immersion test and electrochemical polarization. It is found that the thickness of the coating dose lacks uniformity, with an uneven thickness distribution and an average variation of approximately 2-5gm; the coating can afford cathodic protection to the steel substrate; the corrosion resistance of Zn-Al coatings is better than that of the mechanically plated zinc coatings with same thickness. These conclusions can be applied to improve anti-corrosion performance by mechanically deposit Zn-Al coatings.展开更多
Initial atmospheric corrosion of zinc in the presence of Na2SO4 and (NH4)2SO4 was investigated via quartz crystal microbalance(QCM) in laboratory at relative humidity(RH) of 80% and 25 ℃. The results show that both N...Initial atmospheric corrosion of zinc in the presence of Na2SO4 and (NH4)2SO4 was investigated via quartz crystal microbalance(QCM) in laboratory at relative humidity(RH) of 80% and 25 ℃. The results show that both Na2SO4 and (NH4)2SO4 can accelerate the initial atmospheric corrosion of zinc. The combined effect of Na2SO4 and (NH4)2SO4 on the corrosion of zinc is greater than that caused by (NH4)2SO4 and less than that caused by Na2SO4. Fourier transform infrared spectroscopy(FTIR), X-ray diffractometry(XRD) and scanning electron microscopy(SEM) were used to characterize the corrosion products of zinc. (NH4)2Zn(SO4)2, Zn4SO4(OH)6·5H2O and ZnO present on zinc surface in the presence of (NH4)2SO4 while Zn4SO4(OH)6·5H2O and ZnO are the dominant corrosion products on Na2SO4-treated zinc surface. Probable mechanisms are presented to explain the experimental results.展开更多
Mg(OH)2 nano-particles with fiber-like morphology were prepared by chemical precipitation process,with the bittern from Qinghai Salt Lakes used as Mg2+ raw material and ammonia water as precipitator. The influence of ...Mg(OH)2 nano-particles with fiber-like morphology were prepared by chemical precipitation process,with the bittern from Qinghai Salt Lakes used as Mg2+ raw material and ammonia water as precipitator. The influence of aging procedure on the Mg(OH)2 crystal was investigated by TEM and crystalline size calculation. The Mg(OH)2 nano-particles were characterized by XRD,SEM,TEM and TG-DTA methods. The results indicate that the Mg(OH)2 nano-particles with perfect crystal are obtained after aging procedure above 50 ℃,and the grain size increases with increasing aging temperature and prolonging aging time. Mg(OH)2 particles with fiber-like morphology,20-60 nm in diameter and 300-500 nm in length are observed,Mg(OH)2 will decompose into MgO at temperature range 347-623 ℃.展开更多
Three new highly oxygenated nortriterpenoids,wilsonianadilactones D-F(1-3),were isolated from the leaves and stems of Schisandra wilsoniana.Their structures were established by means of spectroscopic analysis.Compound...Three new highly oxygenated nortriterpenoids,wilsonianadilactones D-F(1-3),were isolated from the leaves and stems of Schisandra wilsoniana.Their structures were established by means of spectroscopic analysis.Compounds 1-3 showed weak anti-HIV-1 activity with the therapeutic index(TI)values(CC50/EC50)greater than 8.16,14.7,and 17.5,respectively.展开更多
Learning a foreign language is based on the master of its vocabulary. Vocabulary is one of the ＇bottlenecks＇ in the learning of English. It will greatly influence the expression in our communication. Both teachers a...Learning a foreign language is based on the master of its vocabulary. Vocabulary is one of the ＇bottlenecks＇ in the learning of English. It will greatly influence the expression in our communication. Both teachers and students need to pay much more attention to the learning of English vocabulary. This paper discusses the study of morphology from the perspective of modern linguistics, including the definitions of morpheme, types of morphemes, morphological structure and the main processes of word-formation of the language. Meanwhile, the author analyzes how the morphology study is applicable to English vocabulary teaching and learning in college, especially explores the purpose of the English vocabulary teaching in college, and finally proposes Some practical approaches of vocabulary teaching from the study of morphology.展开更多
We consider the one-dimensional nonlinear Schrǒdinger equations that describe the dynamics of a Bose-Einstein Condensates with time-dependent scattering length in a complex potential. Our results show that as long as...We consider the one-dimensional nonlinear Schrǒdinger equations that describe the dynamics of a Bose-Einstein Condensates with time-dependent scattering length in a complex potential. Our results show that as long as the integrable relation is satisfied, exact solutions of the one-dimensional nonlinear Schrǒdinger equation can be found in a general closed form, and interactions between two solitons are modulated in a complex potential We find that the changes of the scattering length and trapping potential can be effectively used to control the interaction between two bright soliton.展开更多
The article concerns the average onesided widths of the Sobolev and Besov classes and the classes of functions with bounded moduli of smoothness. The weak asymptotic results are obtained for the corresponding quantities.
The internal structures as well as adsorption and hopping energies of monomers, dimers, trimers, tetramers, pentamers and hexamers of water on Pd（111） have been studied by density functional theory （DFT） plane-wav...The internal structures as well as adsorption and hopping energies of monomers, dimers, trimers, tetramers, pentamers and hexamers of water on Pd（111） have been studied by density functional theory （DFT） plane-wave pseudopotential method which performs the firstprinciples quantum-mechanical calculations to explore the properties of crystals and surfaces in materials. Based on the calculations, we suppose that their absorption is via one water molecule for monomers, dimmers and trimers, but three water molecules for pentamers and hexamers. Moreover, there is one water molecule bonding with Pd atom by O atom in pentamers and hexamers, which explains why pentamers and hexamers are stable. The binding energies of polymers may be used to explain why the trimer comes close to two nearby monomers to form a stable pentamer instead of tetramer. And the difference of mobility of small water clusters is due to their different hopping energies.展开更多
We present some explicit self-similar blow-up solutions and some other solutions of the incompressible threedimensional Navier Stokes equations. These solutions indicate that in C^∞ the solution of Navier-Stokes equa...We present some explicit self-similar blow-up solutions and some other solutions of the incompressible threedimensional Navier Stokes equations. These solutions indicate that in C^∞ the solution of Navier-Stokes equations does not always tend to a solution of Euler equations.展开更多
We analyze the dynamics of a bright soliton in atomic scattering length in an expulsive parabolic potential. Bose-Einstein condensates （BECs） with time-dependent Under a safe ravage of parameters in which the Gross...We analyze the dynamics of a bright soliton in atomic scattering length in an expulsive parabolic potential. Bose-Einstein condensates （BECs） with time-dependent Under a safe ravage of parameters in which the Gross-Pitaevskii （GP） equation is effective in one dimension, our results show that, the dynamics of the bright soliton can be classed into two phases, depending on the value of the scattering length. Meanwhile, there exists a critical value of the absolute value of the atomic scattering length, below which, the dynamics of the bright soliton is very regular. Those phenomena can be useful for developing concrete applications of the nonlinear matter waves. We also obtain the orbital equation of the bright soliton and get some interesting data which may be useful for the experimental observation of the bright soliton and the application of the atom laser with manipulated intensity.展开更多
Boltzmann equation is an equation which is related to the three variables of x, v, t. In this paper, we mainly study the space-uniform Boltzmann equation which unknown function F is not related to the position variabl...Boltzmann equation is an equation which is related to the three variables of x, v, t. In this paper, we mainly study the space-uniform Boltzmann equation which unknown function F is not related to the position variable x. We mainly use the contraction mapping theorem to find the existence of the solution, so our mainly work is to prove the self-mapping, i.e. to prove its uniformly bounded, and then to prove the contraction mapping. There we can get the range of ||B(θ)||L1(L∞), next we can figure out the range of M and T from the conditions what we know. Finally, from these conditions, we can find the existence of the solution.展开更多
China is one of the multi-ethnic countries in the world.It is common for the people in the ethnic areas are using two or more different languages in their social communication.This paper discusses the characteristics ...China is one of the multi-ethnic countries in the world.It is common for the people in the ethnic areas are using two or more different languages in their social communication.This paper discusses the characteristics and regulations of the trilingual education of the Chinese indigenous people as well as the significance of the ethnic minority’s trilingual education against the globalization background from the perspective of socio-linguistics.展开更多
Aiming at the tele-operation instability caused by time delay of interuet information transfer for internet based tele-robotics, this paper proposes a novel control framework for internet based tele-roboties, which ca...Aiming at the tele-operation instability caused by time delay of interuet information transfer for internet based tele-robotics, this paper proposes a novel control framework for internet based tele-roboties, which can guarantee the non-distortion-transfer of control information and reduce the difference of action time between the local simulated virtual robot and the remote real robot. This framework is insensitive to the inherent interact time delay, and differs from other tele-robotics systems that try to use some mathematic models to describe the internet delay or take some assumptions. In order to verify the framework, a 4-DOF fischertechnik industry robot tele-operation system has been developed using the new proposed framework. Experimental results demonstrate the applicable performance of the new framework. The framework is open structured and can be applied to other general purposed tele-operation systems.展开更多
Before the system of mineral title possession paid established,local governments had spent considerably amount of labor,material,money supervising THREE RATES INDEX,but its effects were nearly indivisible and the pric...Before the system of mineral title possession paid established,local governments had spent considerably amount of labor,material,money supervising THREE RATES INDEX,but its effects were nearly indivisible and the price of mineral products was seriously distorted as well.Nevertheless,it is shown that the competitive system of mineral title market is an effective self-enforcing system which can urge mining companies to initiatively improve THREE RATES INDEX and make the price of mineral products more reasonable than before with the GAME THEORY.展开更多
We prove the existence of solutions of the static Landau-Lifshitz equation with multi- direct effective field and with Dirichlet boundary condition,and establish the stability of the solution of Landau-Lifshitz equati...We prove the existence of solutions of the static Landau-Lifshitz equation with multi- direct effective field and with Dirichlet boundary condition,and establish the stability of the solution of Landau-Lifshitz equation with respect to time.展开更多
In this paper, we shall construct some explicit piecewise smooth （global continuous） solutions as well as blow up solutions to the multidimensional Landau-Lifshitz equation, subject to the external magnetic fields b...In this paper, we shall construct some explicit piecewise smooth （global continuous） solutions as well as blow up solutions to the multidimensional Landau-Lifshitz equation, subject to the external magnetic fields being both discontinuous and unbounded. When the external magnetic field is continuous, some explicit exact smooth solutions and blow up solution are also constructed. We also establish some necessary and sufficient conditions to ensure that the solution of multidimensional Landau-Lifshitz equation with external magnetic field converges to the solution of equation without external magnetic field when the external magnetic field tends to zero.展开更多
Let X be a Banach space and Ф be an Orlicz function. Denote by L^Ф（I,X） the space of X-valued （I）-integrable functions on the unit interval I equipped with the Luxemburg norm. For f1,f2,... ,fm ∈ L^Ф（I,X）, a...Let X be a Banach space and Ф be an Orlicz function. Denote by L^Ф（I,X） the space of X-valued （I）-integrable functions on the unit interval I equipped with the Luxemburg norm. For f1,f2,... ,fm ∈ L^Ф（I,X）, a distance formula distv（f1,f2,... ,fm,L^Ф（I,G）） is presented, where G is a close subspace of X. Moreover, some existence and characterization results concerning the best simultaneous approximation of L^Ф （I, G） in L^Ф （I, X） axe given.展开更多
文摘The Honghe Hani Rice Terraces of Yunnan Province have become a national emblem for China and a UNESCO World Heritage Site,but some are beginning to crumble.This research attempts to address why this is happening and what can be done about it.Previous work has failed to adequately address the possible shortcomings of recently introduced seed and water management technologies,their particular effect on rice terraces and the people who depend upon them.In an effort to better understand the issue,field observation was triangulated with in-depth interviews with local people,and the examination of scientific literature.To do this,the authors spent time in China with a translator in a key village known to be first in the area to truly succeed in carving the rice terraces and in making the mountain slope irrigation system required actually working.Results validated by experts in each field indicate that while the new seed and technologies do save water and improve lives,paired with migration,they may also be threatening the long-term viability of rice terracing in the region.The authors conclude that an integrated approach is needed and put forward a strategic blueprint to reinforce ecological,social and economic longevity.They also call for more research into the applicability of these resilience measures in other hybrid rice terracing regions,such as in the Philippines and Vietnam.
基金supported by National Natural Science Foundation of China (Grant No. 50561003)Foundation of Yunnan Provincial Education Department of China (Grant No.07Y41414)
文摘Zn-Al coatings can provide protection to exposed steel parts in most environments. For this reason, the investigation of Zn-Al coatings become very popular in recent years. In order to study the microstructures and properties of mechanically deposited Zn-Al coating, zinc powders and aluminum powders were used to deposit Zn-AI coating by mechanical plating. The microstruetures, phase constitutes and compositions of the coating were observed and analyzed with optical microscopy （OM）, scanning electron microscopy（SEM）, X-ray diffraction（XRD） and X-ray energy-dispersive spectroscopy（EDS）. The results of observation show that the coating consists of almost spherically shaped zinc particles point contacting with each other; the coatings are composed of zinc particles, aluminum particles, interstice, and tin; extra fine zinc powders and some smaller interspersed inclusions are positioned in the interstices. Porosity and thickness of the coating were tested by ferroxyl test and magnetic method. The corrosion resistance of coatings was studied by neutral salt spraying test（NSS）, immersion test and electrochemical polarization. It is found that the thickness of the coating dose lacks uniformity, with an uneven thickness distribution and an average variation of approximately 2-5gm; the coating can afford cathodic protection to the steel substrate; the corrosion resistance of Zn-Al coatings is better than that of the mechanically plated zinc coatings with same thickness. These conclusions can be applied to improve anti-corrosion performance by mechanically deposit Zn-Al coatings.
基金Project(50261004) supported by the National Natural Science Foundation of China
文摘Initial atmospheric corrosion of zinc in the presence of Na2SO4 and (NH4)2SO4 was investigated via quartz crystal microbalance(QCM) in laboratory at relative humidity(RH) of 80% and 25 ℃. The results show that both Na2SO4 and (NH4)2SO4 can accelerate the initial atmospheric corrosion of zinc. The combined effect of Na2SO4 and (NH4)2SO4 on the corrosion of zinc is greater than that caused by (NH4)2SO4 and less than that caused by Na2SO4. Fourier transform infrared spectroscopy(FTIR), X-ray diffractometry(XRD) and scanning electron microscopy(SEM) were used to characterize the corrosion products of zinc. (NH4)2Zn(SO4)2, Zn4SO4(OH)6·5H2O and ZnO present on zinc surface in the presence of (NH4)2SO4 while Zn4SO4(OH)6·5H2O and ZnO are the dominant corrosion products on Na2SO4-treated zinc surface. Probable mechanisms are presented to explain the experimental results.
基金Project supported by Promoting Program of National Engineering Laboratory for Vacuum Metallurgy
文摘Mg(OH)2 nano-particles with fiber-like morphology were prepared by chemical precipitation process,with the bittern from Qinghai Salt Lakes used as Mg2+ raw material and ammonia water as precipitator. The influence of aging procedure on the Mg(OH)2 crystal was investigated by TEM and crystalline size calculation. The Mg(OH)2 nano-particles were characterized by XRD,SEM,TEM and TG-DTA methods. The results indicate that the Mg(OH)2 nano-particles with perfect crystal are obtained after aging procedure above 50 ℃,and the grain size increases with increasing aging temperature and prolonging aging time. Mg(OH)2 particles with fiber-like morphology,20-60 nm in diameter and 300-500 nm in length are observed,Mg(OH)2 will decompose into MgO at temperature range 347-623 ℃.
基金This project was supported financially by the NSFC(No.20802082 and 30830115)the projects from the Chinese Academy of Sciences(KSCX2-EW-Q-10,KSCX1-YW-R-24 and KSCX2-YW-R-185)+2 种基金the Major State Basic Research Development Program of China(No.2009CB522303 and 2009CB940900)the Yong Academic and Technical Leader Rising Foundation of Yunnan Province(2006PY01-47)the Natural Science Foundation of Yunnan Province(2005XY04 and 2006B0042Q).
文摘Three new highly oxygenated nortriterpenoids,wilsonianadilactones D-F(1-3),were isolated from the leaves and stems of Schisandra wilsoniana.Their structures were established by means of spectroscopic analysis.Compounds 1-3 showed weak anti-HIV-1 activity with the therapeutic index(TI)values(CC50/EC50)greater than 8.16,14.7,and 17.5,respectively.
文摘Learning a foreign language is based on the master of its vocabulary. Vocabulary is one of the ＇bottlenecks＇ in the learning of English. It will greatly influence the expression in our communication. Both teachers and students need to pay much more attention to the learning of English vocabulary. This paper discusses the study of morphology from the perspective of modern linguistics, including the definitions of morpheme, types of morphemes, morphological structure and the main processes of word-formation of the language. Meanwhile, the author analyzes how the morphology study is applicable to English vocabulary teaching and learning in college, especially explores the purpose of the English vocabulary teaching in college, and finally proposes Some practical approaches of vocabulary teaching from the study of morphology.
基金supported by National Natural Science Foundation of China under Grant Nos.90406017 and 60525417the National Key Basic Research Special Foundation of China under Grant Nos.2005CB724508 and 2006CB921400
文摘We consider the one-dimensional nonlinear Schrǒdinger equations that describe the dynamics of a Bose-Einstein Condensates with time-dependent scattering length in a complex potential. Our results show that as long as the integrable relation is satisfied, exact solutions of the one-dimensional nonlinear Schrǒdinger equation can be found in a general closed form, and interactions between two solitons are modulated in a complex potential We find that the changes of the scattering length and trapping potential can be effectively used to control the interaction between two bright soliton.
基金Supported by the Foundation of Education Department of Yunnan Province (07Z10533)Supported partly by the National Natural Science Foundation of China (10471010)+1 种基金partly by the project "Representation Theory and Related Topics" of the "985 program" of Beijing Normal UniversitySupported by the Science Foundation of Yunnan University (2008YB027)
文摘The article concerns the average onesided widths of the Sobolev and Besov classes and the classes of functions with bounded moduli of smoothness. The weak asymptotic results are obtained for the corresponding quantities.
基金Supported by the Natural Science Foundation of Yunnan Province (No. 2004B0003M)
文摘The internal structures as well as adsorption and hopping energies of monomers, dimers, trimers, tetramers, pentamers and hexamers of water on Pd（111） have been studied by density functional theory （DFT） plane-wave pseudopotential method which performs the firstprinciples quantum-mechanical calculations to explore the properties of crystals and surfaces in materials. Based on the calculations, we suppose that their absorption is via one water molecule for monomers, dimmers and trimers, but three water molecules for pentamers and hexamers. Moreover, there is one water molecule bonding with Pd atom by O atom in pentamers and hexamers, which explains why pentamers and hexamers are stable. The binding energies of polymers may be used to explain why the trimer comes close to two nearby monomers to form a stable pentamer instead of tetramer. And the difference of mobility of small water clusters is due to their different hopping energies.
文摘We present some explicit self-similar blow-up solutions and some other solutions of the incompressible threedimensional Navier Stokes equations. These solutions indicate that in C^∞ the solution of Navier-Stokes equations does not always tend to a solution of Euler equations.
基金Supported by National Natural Science Foundation of China under Grant Nos.90406017 and 60525417the NKBRSF of China under Grant No.2006CB921400
文摘We analyze the dynamics of a bright soliton in atomic scattering length in an expulsive parabolic potential. Bose-Einstein condensates （BECs） with time-dependent Under a safe ravage of parameters in which the Gross-Pitaevskii （GP） equation is effective in one dimension, our results show that, the dynamics of the bright soliton can be classed into two phases, depending on the value of the scattering length. Meanwhile, there exists a critical value of the absolute value of the atomic scattering length, below which, the dynamics of the bright soliton is very regular. Those phenomena can be useful for developing concrete applications of the nonlinear matter waves. We also obtain the orbital equation of the bright soliton and get some interesting data which may be useful for the experimental observation of the bright soliton and the application of the atom laser with manipulated intensity.
文摘Boltzmann equation is an equation which is related to the three variables of x, v, t. In this paper, we mainly study the space-uniform Boltzmann equation which unknown function F is not related to the position variable x. We mainly use the contraction mapping theorem to find the existence of the solution, so our mainly work is to prove the self-mapping, i.e. to prove its uniformly bounded, and then to prove the contraction mapping. There we can get the range of ||B(θ)||L1(L∞), next we can figure out the range of M and T from the conditions what we know. Finally, from these conditions, we can find the existence of the solution.
文摘China is one of the multi-ethnic countries in the world.It is common for the people in the ethnic areas are using two or more different languages in their social communication.This paper discusses the characteristics and regulations of the trilingual education of the Chinese indigenous people as well as the significance of the ethnic minority’s trilingual education against the globalization background from the perspective of socio-linguistics.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 60776816)Scientific Research Foundation of Education Department of Yunnan Province (Grant No.08Y10326)
文摘Aiming at the tele-operation instability caused by time delay of interuet information transfer for internet based tele-robotics, this paper proposes a novel control framework for internet based tele-roboties, which can guarantee the non-distortion-transfer of control information and reduce the difference of action time between the local simulated virtual robot and the remote real robot. This framework is insensitive to the inherent interact time delay, and differs from other tele-robotics systems that try to use some mathematic models to describe the internet delay or take some assumptions. In order to verify the framework, a 4-DOF fischertechnik industry robot tele-operation system has been developed using the new proposed framework. Experimental results demonstrate the applicable performance of the new framework. The framework is open structured and can be applied to other general purposed tele-operation systems.
文摘Before the system of mineral title possession paid established,local governments had spent considerably amount of labor,material,money supervising THREE RATES INDEX,but its effects were nearly indivisible and the price of mineral products was seriously distorted as well.Nevertheless,it is shown that the competitive system of mineral title market is an effective self-enforcing system which can urge mining companies to initiatively improve THREE RATES INDEX and make the price of mineral products more reasonable than before with the GAME THEORY.
文摘We prove the existence of solutions of the static Landau-Lifshitz equation with multi- direct effective field and with Dirichlet boundary condition,and establish the stability of the solution of Landau-Lifshitz equation with respect to time.
基金Supported by the National Natural Science Foundation of China(No.10861014)The Institute of Mathematical Sciences,Chinese University of Hongkong.
文摘In this paper, we shall construct some explicit piecewise smooth （global continuous） solutions as well as blow up solutions to the multidimensional Landau-Lifshitz equation, subject to the external magnetic fields being both discontinuous and unbounded. When the external magnetic field is continuous, some explicit exact smooth solutions and blow up solution are also constructed. We also establish some necessary and sufficient conditions to ensure that the solution of multidimensional Landau-Lifshitz equation with external magnetic field converges to the solution of equation without external magnetic field when the external magnetic field tends to zero.
基金Supported by the Foundation of the Nationalities Committee of China (Grant No05YN06)the Educational Foundation of Yunnan Province (Grant No07Z10533)
文摘Let X be a Banach space and Ф be an Orlicz function. Denote by L^Ф（I,X） the space of X-valued （I）-integrable functions on the unit interval I equipped with the Luxemburg norm. For f1,f2,... ,fm ∈ L^Ф（I,X）, a distance formula distv（f1,f2,... ,fm,L^Ф（I,G）） is presented, where G is a close subspace of X. Moreover, some existence and characterization results concerning the best simultaneous approximation of L^Ф （I, G） in L^Ф （I, X） axe given.
