In this article, certain Marcinkiewicz integral operators associated to surfaces of revolution on product domains were studied. The Lp boundedness for these operators are established under some rather weak conditions ...In this article, certain Marcinkiewicz integral operators associated to surfaces of revolution on product domains were studied. The Lp boundedness for these operators are established under some rather weak conditions on kernels. The main results essentially improve and extend some known results.展开更多
In this paper, we establish the L^p (R-n+1) boundedness for the commutators of singular integrals associated to surfaces of revolution, { (t,Ф ( | t| ) ): t ∈R^n }, with rough kernels Ω∈ L(IogL)^2(sn...In this paper, we establish the L^p (R-n+1) boundedness for the commutators of singular integrals associated to surfaces of revolution, { (t,Ф ( | t| ) ): t ∈R^n }, with rough kernels Ω∈ L(IogL)^2(sn^-1), if Ф(|t|) = |t|.展开更多
In this paper, the authors establish Lp boundedness for several classes of multiple singular integrals along surfaces of revolution with kernels satisfying rather weak size condition. The results of the corresponding ...In this paper, the authors establish Lp boundedness for several classes of multiple singular integrals along surfaces of revolution with kernels satisfying rather weak size condition. The results of the corresponding maximal truncated singular integrals are also obtained. The main results essentially improve and extend some known results.展开更多
Here we consider the following strongly singular integral TΩ,γ,α,βf(x,t)=∫R^ne^i|y|^-βΩ(y/|y|)/|y|^n+af(x-y,t-γ(|y|))dy, where Ω∈L^p(S^n-1),p〉1,n〉1,α〉0 and γis convex on (0,∞).We p...Here we consider the following strongly singular integral TΩ,γ,α,βf(x,t)=∫R^ne^i|y|^-βΩ(y/|y|)/|y|^n+af(x-y,t-γ(|y|))dy, where Ω∈L^p(S^n-1),p〉1,n〉1,α〉0 and γis convex on (0,∞).We prove that there exists A(p,n) 〉 0 such that if β 〉 A(p,n) (1 +α), then TΩ,γ,α,β is bounded from L^2 (R^n+1) to itself and the constant is independent of γ Furthermore,when Ω∈ C^∞ (S^n-1 ), we will show that TΩ,γ,α,β is bounded from L^2 (R^n+l) to itself only if β〉 2α and the constant is independent of γ.展开更多
In this paper, we investigate the surfaces of revolution under the condition FIl(G) = k(G + C), where r11 is one of the Christoffel-like operators, G is the Gauss map of the surface, k is a non-constant function ...In this paper, we investigate the surfaces of revolution under the condition FIl(G) = k(G + C), where r11 is one of the Christoffel-like operators, G is the Gauss map of the surface, k is a non-constant function and C is a constant vector in Minkowski 3-space.展开更多
We consider the boundedness of the rough singular integral operator T_(?,ψ,h) along a surface of revolution on the Triebel-Lizorkin space F^α_( p,q)(R^n) for Ω ∈ H^1((S^n-1)) and Ω ∈ Llog^+L(S^n-1)...We consider the boundedness of the rough singular integral operator T_(?,ψ,h) along a surface of revolution on the Triebel-Lizorkin space F^α_( p,q)(R^n) for Ω ∈ H^1((S^n-1)) and Ω ∈ Llog^+L(S^n-1) ∪_1展开更多
In this paper,a deterministic theorem is proposed for quadratic rotational curved surface.The relationship between invariants for quadratic rotational curved surface is established.In addition we give each type of equ...In this paper,a deterministic theorem is proposed for quadratic rotational curved surface.The relationship between invariants for quadratic rotational curved surface is established.In addition we give each type of equitions for rotational curved surface using the invariant.展开更多
The catenary shells of revolution are widely used in church constructions due to their unique mechanics'features.To have a better understanding of the deformation and stress of the catenary shells of revolution,we...The catenary shells of revolution are widely used in church constructions due to their unique mechanics'features.To have a better understanding of the deformation and stress of the catenary shells of revolution,we formulate the principal radii for two kinds of catenary shells of revolution and their displacement type governing equations.Numerical simulations are carried out based on both Reissner-Meissner(R-M)mixed formulations and displacement formulations.Our investigations show that both deformation and stress response of elastic catenary shells of revolution are sensitive to its geometric parameter c,and reveal that the mechanics of the catenary shells of revolution has some advantages over the spherical shell for some loadings.Two complete codes in Maple are provided.展开更多
Many factors such as outer diameter, hub ratio, blade numbers, shape and stagger angle affect the performance of small cooling fans. A small cooling fan was simulated using CFD software for three blade stagger angles ...Many factors such as outer diameter, hub ratio, blade numbers, shape and stagger angle affect the performance of small cooling fans. A small cooling fan was simulated using CFD software for three blade stagger angles (30.5°, 37.5°, 44.5°)and obtained the internal flow field and the static characteristics. Research indicated that the stagger angle has an obvious effect on the static characteristics of a fan. For flow rates below 0.0104 mVs, total pressure is the greatest when the stagger angle is 37.5°; flow rates higher than 0.0104 m^3/s, the total pressure is greatest when the stagger angle is 44.5° For the same flow rates, the velocity at inlet of pressure surface increases with in- creasing stagger angle, but the change of velocity on the suction surface is very small. For one model, vortices and the speed of revolution surfaces decrease with tip clearance increasing. But for other three models, increasing the stagger angle, the vortex intensity and speed of revolution surfaces at same height tip clearance increases, simultaneously, the position of vortex offset from the top of the rotor blade to the suction surface.展开更多
We study a functional modelling the progressive lens design,which is a combination of Willmore functional and total Gauss curvature.First,we prove the existence for the minimizers of this class of functionals among th...We study a functional modelling the progressive lens design,which is a combination of Willmore functional and total Gauss curvature.First,we prove the existence for the minimizers of this class of functionals among the class of revolution surfaces rotated by the curves y=f(x)about the x-axis.Then,choosing such a minimiser as background surfaces to approximate the functional by a quadratic functional,we prove the existence and uniqueness of the solution to the Euler-Lagrange equation for the quadratic functionals.Our results not only provide a strictly mathematical proof for numerical methods,but also give a more reasonable and more extensive choice for the background surfaces.展开更多
基金Supported by the NSF of China (G10571122) the NFS of Fujian Province of China (Z0511004)
文摘In this article, certain Marcinkiewicz integral operators associated to surfaces of revolution on product domains were studied. The Lp boundedness for these operators are established under some rather weak conditions on kernels. The main results essentially improve and extend some known results.
基金supported by NSF of China(Grant No.11471033)NCET of China(Grant No.NCET-11-0574)the Fundamental Research Funds for the Central Universities(FRF-TP-12-006B)
文摘In this paper, we establish the L^p (R-n+1) boundedness for the commutators of singular integrals associated to surfaces of revolution, { (t,Ф ( | t| ) ): t ∈R^n }, with rough kernels Ω∈ L(IogL)^2(sn^-1), if Ф(|t|) = |t|.
文摘In this paper, the authors establish Lp boundedness for several classes of multiple singular integrals along surfaces of revolution with kernels satisfying rather weak size condition. The results of the corresponding maximal truncated singular integrals are also obtained. The main results essentially improve and extend some known results.
基金supported by NSFC(Nos.11471288,11371136 and 11671363)NSFZJ(LY14A010015)China Scholarship Council
文摘Here we consider the following strongly singular integral TΩ,γ,α,βf(x,t)=∫R^ne^i|y|^-βΩ(y/|y|)/|y|^n+af(x-y,t-γ(|y|))dy, where Ω∈L^p(S^n-1),p〉1,n〉1,α〉0 and γis convex on (0,∞).We prove that there exists A(p,n) 〉 0 such that if β 〉 A(p,n) (1 +α), then TΩ,γ,α,β is bounded from L^2 (R^n+1) to itself and the constant is independent of γ Furthermore,when Ω∈ C^∞ (S^n-1 ), we will show that TΩ,γ,α,β is bounded from L^2 (R^n+l) to itself only if β〉 2α and the constant is independent of γ.
文摘In this paper, we investigate the surfaces of revolution under the condition FIl(G) = k(G + C), where r11 is one of the Christoffel-like operators, G is the Gauss map of the surface, k is a non-constant function and C is a constant vector in Minkowski 3-space.
基金supported by National Natural Science Foundation of China (Grant Nos. 11371057, 11471033 and 11571160)Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20130003110003)+2 种基金the Fundamental Research Funds for the Central Universities (Grant No. 2014KJJCA10)Grant-in-Aid for Scientific Research (C) (Grant No. 23540228)Japan Society for the Promotion of Science
文摘We consider the boundedness of the rough singular integral operator T_(?,ψ,h) along a surface of revolution on the Triebel-Lizorkin space F^α_( p,q)(R^n) for Ω ∈ H^1((S^n-1)) and Ω ∈ Llog^+L(S^n-1) ∪_1
文摘In this paper,a deterministic theorem is proposed for quadratic rotational curved surface.The relationship between invariants for quadratic rotational curved surface is established.In addition we give each type of equitions for rotational curved surface using the invariant.
基金supported by Xi'an University of Architecture and Technology(Grant No.002/2040221134).
文摘The catenary shells of revolution are widely used in church constructions due to their unique mechanics'features.To have a better understanding of the deformation and stress of the catenary shells of revolution,we formulate the principal radii for two kinds of catenary shells of revolution and their displacement type governing equations.Numerical simulations are carried out based on both Reissner-Meissner(R-M)mixed formulations and displacement formulations.Our investigations show that both deformation and stress response of elastic catenary shells of revolution are sensitive to its geometric parameter c,and reveal that the mechanics of the catenary shells of revolution has some advantages over the spherical shell for some loadings.Two complete codes in Maple are provided.
基金support of Zhejiang Provincial Natural Science Foundation (No.R107635)Zhejiang Provincial Key Science Foundation (2008 C11027)National Natural Science Foundation of China (No.50735004)
文摘Many factors such as outer diameter, hub ratio, blade numbers, shape and stagger angle affect the performance of small cooling fans. A small cooling fan was simulated using CFD software for three blade stagger angles (30.5°, 37.5°, 44.5°)and obtained the internal flow field and the static characteristics. Research indicated that the stagger angle has an obvious effect on the static characteristics of a fan. For flow rates below 0.0104 mVs, total pressure is the greatest when the stagger angle is 37.5°; flow rates higher than 0.0104 m^3/s, the total pressure is greatest when the stagger angle is 44.5° For the same flow rates, the velocity at inlet of pressure surface increases with in- creasing stagger angle, but the change of velocity on the suction surface is very small. For one model, vortices and the speed of revolution surfaces decrease with tip clearance increasing. But for other three models, increasing the stagger angle, the vortex intensity and speed of revolution surfaces at same height tip clearance increases, simultaneously, the position of vortex offset from the top of the rotor blade to the suction surface.
基金This work was supported by the National Natural Science Foundation of China(Grant No.11771237).
文摘We study a functional modelling the progressive lens design,which is a combination of Willmore functional and total Gauss curvature.First,we prove the existence for the minimizers of this class of functionals among the class of revolution surfaces rotated by the curves y=f(x)about the x-axis.Then,choosing such a minimiser as background surfaces to approximate the functional by a quadratic functional,we prove the existence and uniqueness of the solution to the Euler-Lagrange equation for the quadratic functionals.Our results not only provide a strictly mathematical proof for numerical methods,but also give a more reasonable and more extensive choice for the background surfaces.