In article, I present a study on upper and lower statistical convergence, and upper and lower strong fractional weighted mean convergence by moduli for triple sequences. One of the generalizations of the discrete oper...In article, I present a study on upper and lower statistical convergence, and upper and lower strong fractional weighted mean convergence by moduli for triple sequences. One of the generalizations of the discrete operator Cesàro, was weighted mean operators, which are linear operators, too. Given a modulus function f, I established that a triple sequence that is f-upper or lower strong fractional weighted mean convergent, in some supplementary conditions, is also f-lower or upper statistically convergent. The results of this paper adapt the results obtained in [1] and [2] to upper and lower strong fractional weighted mean convergence and to triple sequence concept. Furthermore, new concepts can be applied to the approximation theory, topology, Fourier analysis, analysis interdisciplinary with applications electrical engineering, robotics and other domains.展开更多
This paper presents new existence results for singular discrete boundary value problems. In particular our nonlinearity may be singular in its dependent variable and is allowed to change sign.
In this paper, the method of relaxed boundary conditions is applied to rectangular plates with edges which are a sort of the mixture of simply supported portions and clamped portions, so that the lower limit of fundam...In this paper, the method of relaxed boundary conditions is applied to rectangular plates with edges which are a sort of the mixture of simply supported portions and clamped portions, so that the lower limit of fundamental frequency of such plates is evaluated. A kind of polynomial satisfying the displacement boundary conditions is designed, os that it is enabled to evaluate the upper limit of fundamental frequency by Ritz' method. The practical calculation examples solved by these methods have given satisfactory results. At the end of this paper, it is pointed out that the socalled exact solution of such plates usually evaluated by the force superposition method is essentially a kind of lower limit of solution, if the truncated error of series which occurs in actual calculation is considered.展开更多
In this paper, we establish the existence of upper and lower solutions for a periodic boundary value problems (PBVP for short) of impulsive differential equations. which guarantees the existence of at least one soluti...In this paper, we establish the existence of upper and lower solutions for a periodic boundary value problems (PBVP for short) of impulsive differential equations. which guarantees the existence of at least one solution for the problem. As an application, these results are applied to PBVP of ODE and some examples are given to illustrate our results.展开更多
Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics...Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics,the tight oil enrichment model and its major controlling factors.First,the Quantou Formation is overlaid by high-quality source rocks of the Upper Cretaceous Qingshankou Formation,with the development of nose structure around sag and the broad and continuous distribution of sand bodies.The reservoirs are tight on the whole.Second,the configuration of multiple elements,such as high-quality source rocks,reservoir rocks,fault,overpressure and structure,controls the tight oil enrichment in the Fuyu reservoirs.The source-reservoir combination controls the tight oil distribution pattern.The pressure difference between source and reservoir drives the charging of tight oil.The fault-sandbody transport system determines the migration and accumulation of oil and gas.The positive structure is the favorable place for tight oil enrichment,and the fault-horst zone is the key part of syncline area for tight oil exploration.Third,based on the source-reservoir relationship,transport mode,accumulation dynamics and other elements,three tight oil enrichment models are recognized in the Fuyu reservoirs:(1)vertical or lateral migration of hydrocarbon from source rocks to adjacent reservoir rocks,that is,driven by overpressure,hydrocarbon generated is migrated vertically or laterally to and accumulates in the adjacent reservoir rocks;(2)transport of hydrocarbon through faults between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downward through faults to the sandbodies that are separated from the source rocks;and(3)migration of hydrocarbon through faults and sandbodies between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downwards through faults to the reservoir rocks that are separated from the source rocks,and then migrates laterally through sandbodies.Fourth,the differences in oil source conditions,charging drive,fault distribution,sandbody and reservoir physical properties cause the differential enrichment of tight oil in the Fuyu reservoirs.Comprehensive analysis suggests that the Fuyu reservoir in the Qijia-Gulong Sag has good conditions for tight oil enrichment and has been less explored,and it is an important new zone for tight oil exploration in the future.展开更多
A new upper and lower solution theory is presented for the second order problem (G'(y))'+ f(t, y) = 0 on finite and infinite intervals. The theory on finite intervals is based on a Leray-Schauder alternative,...A new upper and lower solution theory is presented for the second order problem (G'(y))'+ f(t, y) = 0 on finite and infinite intervals. The theory on finite intervals is based on a Leray-Schauder alternative, where as the theory on infinite intervals is based on results on the finite interval and a diagonalization process.展开更多
In this paper,a physical model of coal roadway which is clamped by upper and lower softrock with extra thickness was built according to the characteristics of soft rock strata in china's western mining area.Then,a...In this paper,a physical model of coal roadway which is clamped by upper and lower softrock with extra thickness was built according to the characteristics of soft rock strata in china's western mining area.Then,a series of orthogonal numerical experiments were carried out by selecting the strength and stiffness parameters of soft rock and coal seam as well as the in situ stress of soft rock strata as experimental factors and roadway displacements(convergence displacements of sides,displacement of roof to floor)as experimental indexes.By constructing the F statistics with different inspection levels,evaluation method for influence of the experimental factors on stability indexes were defined.Thus,influence degrees of specified parameters on the stability of roadway were divided into five classes as follows:highly significant influence,significant influence,relatively significant influence,little significant influence,and no influence respectively which realize the quantitative analysis of the influence degrees of experimental factors.The finite element calculation results showed that main failure mode of coal roadway that usually showed as tension failure of coal seam in roof and deformation factors of coal seam had the most remarkable effect on roadway displacements.The conclusions provide theoretical basis for further analysis of the mechanism of"roof burst"in roadway maintenance.展开更多
This paper is concerned with a third-order nonlinear separated boundary value problem. By the Leray-Schauder degree theory and the method of upper and lower solutions, we obtain the existence of at least three solutio...This paper is concerned with a third-order nonlinear separated boundary value problem. By the Leray-Schauder degree theory and the method of upper and lower solutions, we obtain the existence of at least three solutions to the problem.展开更多
In this paper,we deal with a class of boundary value problem.We give the existence of solution under the assumption that there exist lower and upper solutions to the problem.Our result extends and complements the rele...In this paper,we deal with a class of boundary value problem.We give the existence of solution under the assumption that there exist lower and upper solutions to the problem.Our result extends and complements the relevant ones which were obtained by many authors previously.展开更多
To investigate the stratosphere-troposphere exchange(STE)process induced by the gravity waves(GWs)caused by Typhoon Molave(2020)in the upper troposphere and lower stratosphere,we analyzed the ERA5 reanalysis data prov...To investigate the stratosphere-troposphere exchange(STE)process induced by the gravity waves(GWs)caused by Typhoon Molave(2020)in the upper troposphere and lower stratosphere,we analyzed the ERA5 reanalysis data provided by the European Centre for Medium-Range Weather Forecasts and the CMA Tropical Cyclone Best Track Dataset.We also adopted the mesoscale forecast model Weather Research and Forecasting model V4.3 for numerical simulation.Most of the previous studies were about typhoon-induced STE and typhoon-induced GWs,while our research focused on the STE caused by typhoon-induced gravity waves.Our analysis shows that most of the time,the gravity wave signal of Typhoon Molave appeared below the tropopause.It was stronger on the east side of the typhoon center(10°-20°N,110°-120°E)than on the west side,suggesting an eastward tilted structure with height increase.When the GWs in the upper troposphere and lower stratosphere region on the west side of the typhoon center broke up,it produced strong turbulence,resulting in stratosphere-troposphere exchange.At this time,the average potential vorticity vertical flux increased with the average ozone mass mixing ratio.The gravity wave events and STE process simulated by the WRF model were basically consistent with the results of ERA5 reanalysis data,but the time of gravity wave breaking was different.This study indicates that after the breaking of the GWs induced by typhoons,turbulent mixing will also be generated,and thus the STE.展开更多
Based on μ-, T- and H-dependent pairing and number equations and the premise that μ(T) is predominantly the cause of the variation of the upper critical field H<sub>c</sub><sub>2</sub>(T), wh...Based on μ-, T- and H-dependent pairing and number equations and the premise that μ(T) is predominantly the cause of the variation of the upper critical field H<sub>c</sub><sub>2</sub>(T), where μ, T and H denote the chemical potential, temperature and the applied field, respectively, we provide in this paper fits to the empirical H<sub>c</sub><sub>2</sub>(T) data of H<sub>3</sub>S reported by Mozaffari, et al. (2019) and deal with the issue of whether or not H<sub>3</sub>S exhibits the Meissner effect. Employing a variant of the template given by Dogan and Cohen (2021), we examine in detail the results of Hirsch and Marsiglio (2022) who have claimed that H<sub>3</sub>S does not exhibit the Meissner effect and Minkov, et al. (2023) who have claimed that it does. We are thus led to suggest that monitoring the chemical potential (equivalently, the number density of Cooper pairs N<sub>s</sub> at T = T<sub>c</sub>) should shed new light on the issue being addressed.展开更多
This paper is concerned with a class of degenerate and nondegenerate stable diffusion models.By using the upper and lower solution method and Schauder fixed point principle,the author studies the existence of positive...This paper is concerned with a class of degenerate and nondegenerate stable diffusion models.By using the upper and lower solution method and Schauder fixed point principle,the author studies the existence of positive solutions for these stable_diffusion models under some conditions.展开更多
The unprecedented rate of metro construction has led to a highly complex network of metro lines.Tunnels are being overlapped to an ever-increasing degree.This paper investigates the deformation response of double-trac...The unprecedented rate of metro construction has led to a highly complex network of metro lines.Tunnels are being overlapped to an ever-increasing degree.This paper investigates the deformation response of double-track overlapped tunnels in Tianjin,China using finite element analysis(FEA)and field monitoring,considering the attributes of different tunneling forms.With respect to the upper tunneling,the results of the FEA and field monitoring showed that the maximum vertical displacements of the ground surface during the tail passage were 2.06 mm,2.25 mm and 2.39 mm obtained by the FEA,field monitoring and Peck calculation,respectively;the heaves on the vertical displacement curve were observed at 8 m(1.25D,where D is the diameter of the tunnel)away from the center of the tunnel and the curve at both sides was asymmetrical.Furthermore,the crown and bottom produce approximately0.38 mm and 1.26 mm of contraction,respectively.The results of the FEA of the upper and lower sections demonstrated that the tunneling form has an obvious influence on the deformation response of the double-track overlapped tunnel.Compared with the upper tunneling,the lower tunneling exerted significantly less influence on the deformation response,which manifested as a smaller displacement of the strata and deformation of the existing tunnel.The results of this study on overlapped tunnels can provide a reference for similar projects in the future.展开更多
In this paper, the existence and uniqueness of solutions for boundary valueproblem x′′′=f(t, x, x′, x″), x(0)=A, x′(0)=B, g(x′(1), x″(1))=0 are studied byusing Volterra type operator and upper and lower soluti...In this paper, the existence and uniqueness of solutions for boundary valueproblem x′′′=f(t, x, x′, x″), x(0)=A, x′(0)=B, g(x′(1), x″(1))=0 are studied byusing Volterra type operator and upper and lower solutions. Our results improve someknown works.展开更多
This paper deals with the singularity and global regularity tor a class oI nonlinear porous medium system with time-dependent coefficients under homogeneous Dirichlet boundary conditions. First, by comparison principl...This paper deals with the singularity and global regularity tor a class oI nonlinear porous medium system with time-dependent coefficients under homogeneous Dirichlet boundary conditions. First, by comparison principle, some global regularity results are established. Secondly, using some differential inequality technique, we investigate the blow-up solution to the initial-boundary value problem. Furthermore, upper and lower bounds for the maximum blow-up time under some appropriate hypotheses are derived as long as blow-up Occurs.展开更多
By using the full-core plus correlation (FCPC) type wave functions, the accurate charge densities p(0) at the nucleus and the radial expectation values of the ground states for the lithium-like systems with Z =- 2...By using the full-core plus correlation (FCPC) type wave functions, the accurate charge densities p(0) at the nucleus and the radial expectation values of the ground states for the lithium-like systems with Z =- 21 to 30 are obtained. The determinantal conditions and the electron-nucleus cusp condition are used to calculate the inequalities of the upper and the lower bounds to p(0) with two or more expectation values. These inequalities, derived by Angulo and Dehesa [Phys. Rev. A 44 1516 (1991)], are verified to be also valid for these ions with higher nuclear charge. The present results show that the wave functions used in this paper are satisfactory in the whole configuration space for these ions with higher nuclear charge.展开更多
The purpose of this paper is to introduce the notions of <em>m</em>-asymmetric semiopen sets and <em>M</em>-asymmetric semicontinuous multifunctions defined between asymmetric sets satisfying c...The purpose of this paper is to introduce the notions of <em>m</em>-asymmetric semiopen sets and <em>M</em>-asymmetric semicontinuous multifunctions defined between asymmetric sets satisfying certain minimal conditions in the framework of bitopological spaces. Some new characterizations of <em>m</em>-asymmetric semiopen sets and <em>M</em>-asymmetric semicontinuous multifunctions will be investigated and several fundamental properties will be obtained.展开更多
This paper is devoted to the study of a three-dimensional delayed system with nonlocal diffusion and partial quasi-monotonicity. By developing a new definition of upper-lower solutions and a new cross iteration scheme...This paper is devoted to the study of a three-dimensional delayed system with nonlocal diffusion and partial quasi-monotonicity. By developing a new definition of upper-lower solutions and a new cross iteration scheme, we establish some existence results of traveling wave solutions. The results are applied to a nonlocal diffusion model which takes the three-species Lotka-Volterra model as its special case.展开更多
Based on the observational data as well as data of satellite, NCEP reanalysis and moist potential vortex, the heavy rainfall event that occurred away from the outer cycle of tropical depression Kaemi (No.0605) on July...Based on the observational data as well as data of satellite, NCEP reanalysis and moist potential vortex, the heavy rainfall event that occurred away from the outer cycle of tropical depression Kaemi (No.0605) on July 27, 2006 in Shandong Peninsula has been analyzed. The results show that there are three severe convective cloud clusters during the heavy rainfall. The uprightness of coupling pattern between upper-layer jet and low jet and a divergence area, which appeared in the right of upper-layer jet, provided favorable environmental conditions for convective cloud clusters. The strong convective weather happens over the prefrontal warm sector and the storm rainfall mainly distributes in the front of a high-energy area. Positive vorticity distribution and transportation of warm advection in low levels provide dynamic and thermal conditions for the rainstorm. The spatial-temporal evolvements of physical variable fields and MPV2 as the horizontal component of moist potential vorticity show that the rain intensity change is determined by upper and low level jets and the area of MPV2>0 occurs at the front of the low jet cores.展开更多
A method of localization is proposed to lower the high order of equations in FEM calcula- tion for the stability of a complex thin-walled structure.The localized analysis enables us to obtain both the upper and lower ...A method of localization is proposed to lower the high order of equations in FEM calcula- tion for the stability of a complex thin-walled structure.The localized analysis enables us to obtain both the upper and lower limits for the bifurcating point in a whole linear elastic structural system,as well as an ap- proximate solution to asymptotic post-buckling problem.Some numerical examples are included.展开更多
文摘In article, I present a study on upper and lower statistical convergence, and upper and lower strong fractional weighted mean convergence by moduli for triple sequences. One of the generalizations of the discrete operator Cesàro, was weighted mean operators, which are linear operators, too. Given a modulus function f, I established that a triple sequence that is f-upper or lower strong fractional weighted mean convergent, in some supplementary conditions, is also f-lower or upper statistically convergent. The results of this paper adapt the results obtained in [1] and [2] to upper and lower strong fractional weighted mean convergence and to triple sequence concept. Furthermore, new concepts can be applied to the approximation theory, topology, Fourier analysis, analysis interdisciplinary with applications electrical engineering, robotics and other domains.
文摘This paper presents new existence results for singular discrete boundary value problems. In particular our nonlinearity may be singular in its dependent variable and is allowed to change sign.
文摘In this paper, the method of relaxed boundary conditions is applied to rectangular plates with edges which are a sort of the mixture of simply supported portions and clamped portions, so that the lower limit of fundamental frequency of such plates is evaluated. A kind of polynomial satisfying the displacement boundary conditions is designed, os that it is enabled to evaluate the upper limit of fundamental frequency by Ritz' method. The practical calculation examples solved by these methods have given satisfactory results. At the end of this paper, it is pointed out that the socalled exact solution of such plates usually evaluated by the force superposition method is essentially a kind of lower limit of solution, if the truncated error of series which occurs in actual calculation is considered.
文摘In this paper, we establish the existence of upper and lower solutions for a periodic boundary value problems (PBVP for short) of impulsive differential equations. which guarantees the existence of at least one solution for the problem. As an application, these results are applied to PBVP of ODE and some examples are given to illustrate our results.
基金Supported by the PetroChina Science and Technology Major Project(2016E0201)。
文摘Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics,the tight oil enrichment model and its major controlling factors.First,the Quantou Formation is overlaid by high-quality source rocks of the Upper Cretaceous Qingshankou Formation,with the development of nose structure around sag and the broad and continuous distribution of sand bodies.The reservoirs are tight on the whole.Second,the configuration of multiple elements,such as high-quality source rocks,reservoir rocks,fault,overpressure and structure,controls the tight oil enrichment in the Fuyu reservoirs.The source-reservoir combination controls the tight oil distribution pattern.The pressure difference between source and reservoir drives the charging of tight oil.The fault-sandbody transport system determines the migration and accumulation of oil and gas.The positive structure is the favorable place for tight oil enrichment,and the fault-horst zone is the key part of syncline area for tight oil exploration.Third,based on the source-reservoir relationship,transport mode,accumulation dynamics and other elements,three tight oil enrichment models are recognized in the Fuyu reservoirs:(1)vertical or lateral migration of hydrocarbon from source rocks to adjacent reservoir rocks,that is,driven by overpressure,hydrocarbon generated is migrated vertically or laterally to and accumulates in the adjacent reservoir rocks;(2)transport of hydrocarbon through faults between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downward through faults to the sandbodies that are separated from the source rocks;and(3)migration of hydrocarbon through faults and sandbodies between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downwards through faults to the reservoir rocks that are separated from the source rocks,and then migrates laterally through sandbodies.Fourth,the differences in oil source conditions,charging drive,fault distribution,sandbody and reservoir physical properties cause the differential enrichment of tight oil in the Fuyu reservoirs.Comprehensive analysis suggests that the Fuyu reservoir in the Qijia-Gulong Sag has good conditions for tight oil enrichment and has been less explored,and it is an important new zone for tight oil exploration in the future.
基金Supported by Grant No.201/01/1451 of the Grant Agency of Czech Republicthe Council of Czech Government J14/98:153100011
文摘A new upper and lower solution theory is presented for the second order problem (G'(y))'+ f(t, y) = 0 on finite and infinite intervals. The theory on finite intervals is based on a Leray-Schauder alternative, where as the theory on infinite intervals is based on results on the finite interval and a diagonalization process.
基金supported by the National Natural Science Foundation of China(Grant No.51174128)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20123718110007).
文摘In this paper,a physical model of coal roadway which is clamped by upper and lower softrock with extra thickness was built according to the characteristics of soft rock strata in china's western mining area.Then,a series of orthogonal numerical experiments were carried out by selecting the strength and stiffness parameters of soft rock and coal seam as well as the in situ stress of soft rock strata as experimental factors and roadway displacements(convergence displacements of sides,displacement of roof to floor)as experimental indexes.By constructing the F statistics with different inspection levels,evaluation method for influence of the experimental factors on stability indexes were defined.Thus,influence degrees of specified parameters on the stability of roadway were divided into five classes as follows:highly significant influence,significant influence,relatively significant influence,little significant influence,and no influence respectively which realize the quantitative analysis of the influence degrees of experimental factors.The finite element calculation results showed that main failure mode of coal roadway that usually showed as tension failure of coal seam in roof and deformation factors of coal seam had the most remarkable effect on roadway displacements.The conclusions provide theoretical basis for further analysis of the mechanism of"roof burst"in roadway maintenance.
基金supported by the National Natural Science Foundation of China (11071205)the NSF of Jiangsu Province (BK2008119)+1 种基金the NSF of the Education Department of Jiangsu Provincethe Innovation Project of Jiangsu Province Postgraduate Project
文摘This paper is concerned with a third-order nonlinear separated boundary value problem. By the Leray-Schauder degree theory and the method of upper and lower solutions, we obtain the existence of at least three solutions to the problem.
基金The work was supported by NNSF of China (No.10571021).
文摘In this paper,we deal with a class of boundary value problem.We give the existence of solution under the assumption that there exist lower and upper solutions to the problem.Our result extends and complements the relevant ones which were obtained by many authors previously.
基金Guangdong Basic and Applied Basic Research Foundation(2023A1515011323)National Natural Science Foun-dation of China(42130604,42130605,72293604)+4 种基金Guangdong Provincial Observation and Research Station for Tropical Ocean Environment in Western Coastal Waters(GSTOEW)First-Class Discipline Plan of Guangdong Province(080503032101,231420003)Fundamental Research Funds for the Central Universities(202362001,202072010)China Scholarship Council(202208440223)Natural Science Foundation of Shanghai(23ZR1473800)。
文摘To investigate the stratosphere-troposphere exchange(STE)process induced by the gravity waves(GWs)caused by Typhoon Molave(2020)in the upper troposphere and lower stratosphere,we analyzed the ERA5 reanalysis data provided by the European Centre for Medium-Range Weather Forecasts and the CMA Tropical Cyclone Best Track Dataset.We also adopted the mesoscale forecast model Weather Research and Forecasting model V4.3 for numerical simulation.Most of the previous studies were about typhoon-induced STE and typhoon-induced GWs,while our research focused on the STE caused by typhoon-induced gravity waves.Our analysis shows that most of the time,the gravity wave signal of Typhoon Molave appeared below the tropopause.It was stronger on the east side of the typhoon center(10°-20°N,110°-120°E)than on the west side,suggesting an eastward tilted structure with height increase.When the GWs in the upper troposphere and lower stratosphere region on the west side of the typhoon center broke up,it produced strong turbulence,resulting in stratosphere-troposphere exchange.At this time,the average potential vorticity vertical flux increased with the average ozone mass mixing ratio.The gravity wave events and STE process simulated by the WRF model were basically consistent with the results of ERA5 reanalysis data,but the time of gravity wave breaking was different.This study indicates that after the breaking of the GWs induced by typhoons,turbulent mixing will also be generated,and thus the STE.
文摘Based on μ-, T- and H-dependent pairing and number equations and the premise that μ(T) is predominantly the cause of the variation of the upper critical field H<sub>c</sub><sub>2</sub>(T), where μ, T and H denote the chemical potential, temperature and the applied field, respectively, we provide in this paper fits to the empirical H<sub>c</sub><sub>2</sub>(T) data of H<sub>3</sub>S reported by Mozaffari, et al. (2019) and deal with the issue of whether or not H<sub>3</sub>S exhibits the Meissner effect. Employing a variant of the template given by Dogan and Cohen (2021), we examine in detail the results of Hirsch and Marsiglio (2022) who have claimed that H<sub>3</sub>S does not exhibit the Meissner effect and Minkov, et al. (2023) who have claimed that it does. We are thus led to suggest that monitoring the chemical potential (equivalently, the number density of Cooper pairs N<sub>s</sub> at T = T<sub>c</sub>) should shed new light on the issue being addressed.
文摘This paper is concerned with a class of degenerate and nondegenerate stable diffusion models.By using the upper and lower solution method and Schauder fixed point principle,the author studies the existence of positive solutions for these stable_diffusion models under some conditions.
基金financially supported by the Open Project of the State Key Laboratory of Disaster Reduction in Civil Engineering(Grant No.SLDRCE17-01)the National Key Research and Development Program of China(Grant No.2017YFC0805402)the National Natural Science Foundation of China(Grant No.51808387)。
文摘The unprecedented rate of metro construction has led to a highly complex network of metro lines.Tunnels are being overlapped to an ever-increasing degree.This paper investigates the deformation response of double-track overlapped tunnels in Tianjin,China using finite element analysis(FEA)and field monitoring,considering the attributes of different tunneling forms.With respect to the upper tunneling,the results of the FEA and field monitoring showed that the maximum vertical displacements of the ground surface during the tail passage were 2.06 mm,2.25 mm and 2.39 mm obtained by the FEA,field monitoring and Peck calculation,respectively;the heaves on the vertical displacement curve were observed at 8 m(1.25D,where D is the diameter of the tunnel)away from the center of the tunnel and the curve at both sides was asymmetrical.Furthermore,the crown and bottom produce approximately0.38 mm and 1.26 mm of contraction,respectively.The results of the FEA of the upper and lower sections demonstrated that the tunneling form has an obvious influence on the deformation response of the double-track overlapped tunnel.Compared with the upper tunneling,the lower tunneling exerted significantly less influence on the deformation response,which manifested as a smaller displacement of the strata and deformation of the existing tunnel.The results of this study on overlapped tunnels can provide a reference for similar projects in the future.
文摘In this paper, the existence and uniqueness of solutions for boundary valueproblem x′′′=f(t, x, x′, x″), x(0)=A, x′(0)=B, g(x′(1), x″(1))=0 are studied byusing Volterra type operator and upper and lower solutions. Our results improve someknown works.
基金supported in part by NSFC(11571243)Sichuan Youth Science and Technology Foundation(2014JQ0003)+1 种基金Fundamental Research Funds for the Central Universities(2682016CX116)Project of Education Department of Sichuan Province(14226423)
文摘This paper deals with the singularity and global regularity tor a class oI nonlinear porous medium system with time-dependent coefficients under homogeneous Dirichlet boundary conditions. First, by comparison principle, some global regularity results are established. Secondly, using some differential inequality technique, we investigate the blow-up solution to the initial-boundary value problem. Furthermore, upper and lower bounds for the maximum blow-up time under some appropriate hypotheses are derived as long as blow-up Occurs.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11074102)
文摘By using the full-core plus correlation (FCPC) type wave functions, the accurate charge densities p(0) at the nucleus and the radial expectation values of the ground states for the lithium-like systems with Z =- 21 to 30 are obtained. The determinantal conditions and the electron-nucleus cusp condition are used to calculate the inequalities of the upper and the lower bounds to p(0) with two or more expectation values. These inequalities, derived by Angulo and Dehesa [Phys. Rev. A 44 1516 (1991)], are verified to be also valid for these ions with higher nuclear charge. The present results show that the wave functions used in this paper are satisfactory in the whole configuration space for these ions with higher nuclear charge.
文摘The purpose of this paper is to introduce the notions of <em>m</em>-asymmetric semiopen sets and <em>M</em>-asymmetric semicontinuous multifunctions defined between asymmetric sets satisfying certain minimal conditions in the framework of bitopological spaces. Some new characterizations of <em>m</em>-asymmetric semiopen sets and <em>M</em>-asymmetric semicontinuous multifunctions will be investigated and several fundamental properties will be obtained.
基金Supported by the Natural Science Foundation of China (11171120)the Doctoral Program of Higher Education of China (20094407110001)Natural Science Foundation of Guangdong Province (10151063101000003)
文摘This paper is devoted to the study of a three-dimensional delayed system with nonlocal diffusion and partial quasi-monotonicity. By developing a new definition of upper-lower solutions and a new cross iteration scheme, we establish some existence results of traveling wave solutions. The results are applied to a nonlocal diffusion model which takes the three-species Lotka-Volterra model as its special case.
文摘Based on the observational data as well as data of satellite, NCEP reanalysis and moist potential vortex, the heavy rainfall event that occurred away from the outer cycle of tropical depression Kaemi (No.0605) on July 27, 2006 in Shandong Peninsula has been analyzed. The results show that there are three severe convective cloud clusters during the heavy rainfall. The uprightness of coupling pattern between upper-layer jet and low jet and a divergence area, which appeared in the right of upper-layer jet, provided favorable environmental conditions for convective cloud clusters. The strong convective weather happens over the prefrontal warm sector and the storm rainfall mainly distributes in the front of a high-energy area. Positive vorticity distribution and transportation of warm advection in low levels provide dynamic and thermal conditions for the rainstorm. The spatial-temporal evolvements of physical variable fields and MPV2 as the horizontal component of moist potential vorticity show that the rain intensity change is determined by upper and low level jets and the area of MPV2>0 occurs at the front of the low jet cores.
基金Project supported by National Natural Science Foundation of China
文摘A method of localization is proposed to lower the high order of equations in FEM calcula- tion for the stability of a complex thin-walled structure.The localized analysis enables us to obtain both the upper and lower limits for the bifurcating point in a whole linear elastic structural system,as well as an ap- proximate solution to asymptotic post-buckling problem.Some numerical examples are included.