[ Objective] The difference of mineral element content in healthy bark of P. armandii and bark affected by C. nbicola were compared, which would provide theoretical foundation for exploring new ways to control the dis...[ Objective] The difference of mineral element content in healthy bark of P. armandii and bark affected by C. nbicola were compared, which would provide theoretical foundation for exploring new ways to control the disease by artificial water and fertilizer. [ Method] Inductively Coupled Plasma Optical Emission Spectrometer（ ICP-OES）was adopted to measure the variation of mineral elements content in bark after P. armandii was affected by C. nbicola. [Result] 45 mineral elements in the healthy bark and 46 mineral elements in affected bark caused by C. ribicola were detected. These mineral elements contained 14 kinds of mineral elements which were necessary for plant growth and 31 kinds of other mineral elements （32 kinds after affected disease）. The total content of mineral elements in affected bark of P. armandii decreased for 15.77%, in which necessary elements for plant growth decreased for 15.54% and other elements decreased for 17.07%. The content of Ca decreased the most, decrease rate was about 75%. The order of content was also changed, they were Na 〉 Ca 〉 B 〉 K 〉 Si 〉 Mg 〉 S 〉 P in healthy bark, and Na 〉 B 〉 K 〉 Ca 〉 Mg 〉 P 〉 Si 〉 S in affected bark. [ Conclusion] The results laid foundation for controlling C. ribicola through application of mineral elements.展开更多
The lowest order Pl-nonconforming triangular finite element method （FEM） for elliptic and parabolic interface problems is investigated. Under some reasonable regularity assumptions on the exact solutions, the optima...The lowest order Pl-nonconforming triangular finite element method （FEM） for elliptic and parabolic interface problems is investigated. Under some reasonable regularity assumptions on the exact solutions, the optimal order error estimates are obtained in the broken energy norm. Finally, some numerical results are provided to verify the theoretical analysis.展开更多
The effect of rare earth （RE） elements on the morphologies and sizes of Si phases in the hypereutectic A1-Si alloys modified with P was investigated. The results show that the addition of La element to the hypereute...The effect of rare earth （RE） elements on the morphologies and sizes of Si phases in the hypereutectic A1-Si alloys modified with P was investigated. The results show that the addition of La element to the hypereutectic A1-Si alloys can enhance the effect of P element on the modification of the primary Si phases. In the multiplex modification of RE-P, the primary Si phase is refiner and the shape of the eutectic Si is changed from long needle-like to short rod-like. Moreover, the agglomeration rate of the primary Si phase is slowed greatly. Even the melt is held for 6 h, the average size of the primary Si phase is still satisfied. The results analyzed by scanning electron microscope （SEM） indicate that La is richer at A1-Si interface than that in α-A1 or primary Si phase. The higher the La content in the A1-Si interface, the smaller the primary Si phase.展开更多
In the present paper, we give some sufficient conditions for the commutativity of restricted Lie superalgebras and characterize some properties of restricted Lie superalgebras with semisimple elements.
In this paper, we establish the maximum norm estimates of the solutions of the finite volume element method （FVE） based on the P1 conforming element for the non-selfadjoint and indefinite elliptic problems.
In this paper, we prove the existence, uniqueness and uniform convergence of the solution of finite volume element method based on the P1 conforming element for non-selfadjoint and indefinite elliptic problems under m...In this paper, we prove the existence, uniqueness and uniform convergence of the solution of finite volume element method based on the P1 conforming element for non-selfadjoint and indefinite elliptic problems under minimal elliptic regularity assumption.展开更多
Using Moore-Penrose inverse theory, a set of formulations for calculating the static responses of a changed finite element structure are given in this paper. Using these formulations by structural analysis may elimina...Using Moore-Penrose inverse theory, a set of formulations for calculating the static responses of a changed finite element structure are given in this paper. Using these formulations by structural analysis may eliminate the need of assembling the stiffness matrix and solving a set of simultaneous equations.展开更多
The paper investigates the h-p version of the infinite element method. An exponential conver gence can be abtained by a small amount of computing work.
高耸结构P-Δ效应的传统分析方法一般难以考虑时变轴力作用,有可能会低估P-Δ效应对结构安全性的影响.本文应用求积单元法(weak form quadrature element method,QEM),针对分布质量结构体系和含有集中质量的结构体系分别建立Hermite型...高耸结构P-Δ效应的传统分析方法一般难以考虑时变轴力作用,有可能会低估P-Δ效应对结构安全性的影响.本文应用求积单元法(weak form quadrature element method,QEM),针对分布质量结构体系和含有集中质量的结构体系分别建立Hermite型求积单元模型,发展了一种高耸结构P-Δ效应高阶精确分析方法.该方法能够应用于具有突变质量的结构体系,可处理任意轴向荷载引起的动力P-Δ效应问题,无需迭代计算即可获得高精度的P-Δ效应解答,同时能准确地揭示竖向荷载以及时变轴力对高耸结构特性的影响规律.通过对3个不同类型案例的比较分析,验证了本文方法的可行性和准确性.数值分析结果表明,本文方法可以实现高精度的P-Δ效应分析,对于质量均匀分布和含有集中质量的结构体系仅需使用一个求积单元即可获得非常精确的动态响应结果.展开更多
Geometrically nonlinear stiffness matrix due to large displacement small strain was firstly formulated explicitly for the basic components of pantographic foldable structures,namely, the uniplet, derived from a three ...Geometrically nonlinear stiffness matrix due to large displacement small strain was firstly formulated explicitly for the basic components of pantographic foldable structures,namely, the uniplet, derived from a three node beam element.The formulation of the uniplet stiffness matrix is based on the precise nonlinear finite element theory and the displacement harmonized and internal force constraints are applied directly to the deformation modes of the three node beam element. The formulations were derived in general form, and can be simplified for particular foldable structures, such as flat, cylindrical and spherical structures.Finally, two examples were presented to illustrate the applications of the stiffness matrix evolved.展开更多
基金Supported by The 10~(th) Five-Years Key Programs for Science and Technology Development of Yunnan Province(2003NG12)~~
文摘[ Objective] The difference of mineral element content in healthy bark of P. armandii and bark affected by C. nbicola were compared, which would provide theoretical foundation for exploring new ways to control the disease by artificial water and fertilizer. [ Method] Inductively Coupled Plasma Optical Emission Spectrometer（ ICP-OES）was adopted to measure the variation of mineral elements content in bark after P. armandii was affected by C. nbicola. [Result] 45 mineral elements in the healthy bark and 46 mineral elements in affected bark caused by C. ribicola were detected. These mineral elements contained 14 kinds of mineral elements which were necessary for plant growth and 31 kinds of other mineral elements （32 kinds after affected disease）. The total content of mineral elements in affected bark of P. armandii decreased for 15.77%, in which necessary elements for plant growth decreased for 15.54% and other elements decreased for 17.07%. The content of Ca decreased the most, decrease rate was about 75%. The order of content was also changed, they were Na 〉 Ca 〉 B 〉 K 〉 Si 〉 Mg 〉 S 〉 P in healthy bark, and Na 〉 B 〉 K 〉 Ca 〉 Mg 〉 P 〉 Si 〉 S in affected bark. [ Conclusion] The results laid foundation for controlling C. ribicola through application of mineral elements.
基金Project supported by the National Natural Science Foundation of China(No.11271340)
文摘The lowest order Pl-nonconforming triangular finite element method （FEM） for elliptic and parabolic interface problems is investigated. Under some reasonable regularity assumptions on the exact solutions, the optimal order error estimates are obtained in the broken energy norm. Finally, some numerical results are provided to verify the theoretical analysis.
基金supported by the National Natural Science Foundation of China （Grant No.50075051）
文摘The effect of rare earth （RE） elements on the morphologies and sizes of Si phases in the hypereutectic A1-Si alloys modified with P was investigated. The results show that the addition of La element to the hypereutectic A1-Si alloys can enhance the effect of P element on the modification of the primary Si phases. In the multiplex modification of RE-P, the primary Si phase is refiner and the shape of the eutectic Si is changed from long needle-like to short rod-like. Moreover, the agglomeration rate of the primary Si phase is slowed greatly. Even the melt is held for 6 h, the average size of the primary Si phase is still satisfied. The results analyzed by scanning electron microscope （SEM） indicate that La is richer at A1-Si interface than that in α-A1 or primary Si phase. The higher the La content in the A1-Si interface, the smaller the primary Si phase.
基金The Youth Science Foundation of Northeast Normal University (111494027) and the NNSF (10271076) of China.
文摘In the present paper, we give some sufficient conditions for the commutativity of restricted Lie superalgebras and characterize some properties of restricted Lie superalgebras with semisimple elements.
基金The Major State Basic Research Program (19871051) of China and the NNSP (19972039) of China.
文摘In this paper, we establish the maximum norm estimates of the solutions of the finite volume element method （FVE） based on the P1 conforming element for the non-selfadjoint and indefinite elliptic problems.
基金The Major State Basic Research Program (19871051) of China the NNSF (19972039) of China and Yantai University Doctor Foundation (SX03B20).
文摘In this paper, we prove the existence, uniqueness and uniform convergence of the solution of finite volume element method based on the P1 conforming element for non-selfadjoint and indefinite elliptic problems under minimal elliptic regularity assumption.
文摘Using Moore-Penrose inverse theory, a set of formulations for calculating the static responses of a changed finite element structure are given in this paper. Using these formulations by structural analysis may eliminate the need of assembling the stiffness matrix and solving a set of simultaneous equations.
基金The research was supported by the Doctoral Program Foundation of Chinese UniversitiesNational Natural Science Foundation of China (19771021)
文摘The paper investigates the h-p version of the infinite element method. An exponential conver gence can be abtained by a small amount of computing work.
文摘高耸结构P-Δ效应的传统分析方法一般难以考虑时变轴力作用,有可能会低估P-Δ效应对结构安全性的影响.本文应用求积单元法(weak form quadrature element method,QEM),针对分布质量结构体系和含有集中质量的结构体系分别建立Hermite型求积单元模型,发展了一种高耸结构P-Δ效应高阶精确分析方法.该方法能够应用于具有突变质量的结构体系,可处理任意轴向荷载引起的动力P-Δ效应问题,无需迭代计算即可获得高精度的P-Δ效应解答,同时能准确地揭示竖向荷载以及时变轴力对高耸结构特性的影响规律.通过对3个不同类型案例的比较分析,验证了本文方法的可行性和准确性.数值分析结果表明,本文方法可以实现高精度的P-Δ效应分析,对于质量均匀分布和含有集中质量的结构体系仅需使用一个求积单元即可获得非常精确的动态响应结果.
基金Natural Science Foundation of China (No.10 10 2 0 10 )
文摘Geometrically nonlinear stiffness matrix due to large displacement small strain was firstly formulated explicitly for the basic components of pantographic foldable structures,namely, the uniplet, derived from a three node beam element.The formulation of the uniplet stiffness matrix is based on the precise nonlinear finite element theory and the displacement harmonized and internal force constraints are applied directly to the deformation modes of the three node beam element. The formulations were derived in general form, and can be simplified for particular foldable structures, such as flat, cylindrical and spherical structures.Finally, two examples were presented to illustrate the applications of the stiffness matrix evolved.
