查看更多>>摘要：In this paper,a semilinear pseudo-parabolic equation with a general nonlin-earity and singular potential is considered.We prove the local existence of solution by Galerkin method and contraction mapping theorem.Moreover,we prove the blow-up of solution and estimate the upper bound of the blow-up time for J(uo)≤0.Finally,we prove the finite time blow-up and estimate the upper bound of blow-up time for J(uo)＞0.
查看更多>>摘要：In this paper,a discrete predator-prey model with prey refuge is investigated.It is proved that the model undergoes codimension-2 bifurcations associated with 1∶2 and 1∶3 resonances.The bifurcation diagrams and phase portraits show that the model has some interesting complex dynamical behaviors,such as limit cycle,periodic solutions,chaos and codimension-1 bifurcations.
查看更多>>摘要：This paper is concerned with ultrahigh dimensional data analysis,which has become increasingly important in diverse scientific fields.We develop a sure independence screening procedure via the measure of conditional mean dependence based on Copula(CC-SIS,for short).The CC-SIS can be implemented as easily as the sure independence screening procedures which respectively based on the Pearson correlation,conditional mean and distance correlation(SIS,SIRS and DC-SIS,for short)and can significantly improve the performance of feature screening.We establish the sure screening property for the CC-SIS,and conduct simulations to examine its finite sample performance.Numerical comparison indicates that the CC-SIS performs better than the other two methods in various models.At last,we also illustrate the CC-SIS through a real data example.
查看更多>>摘要：Let D be a weighted digraph with n vertices in which each arc has been assigned a positive number.Let A(D)be the adjacency matrix of D and W(D)=diag(w1+,w2,...,wn+).In this paper,we study the matrix Aα(D),which is defined as Aα(D)=αW(D)+(1-α)A(D),0≤α≤1.The spectral radius of Aα(D)is called the Aα spectral radius of D,denoted by λα(D).We obtain some upper bounds on the Aα spectral radius of strongly connected irregular weighted digraphs.
查看更多>>摘要：In this paper,we study the reiterated homogenization operators Le=-div(A(x/e,x/e2)▽).We establish the homogenized problem and representation equa-tion by introducing the two correctors.As a consequence,we obtain the H01 and L2 convergence estimates of solutions.
查看更多>>摘要：We prove a generalization of the classical Gauss-Bonnet formula for a conical metric on a compact Riemann surface provided that the Gaussian curvature is Lebesgue integrable with respect to the area form of the metric.We also construct explicitly some conical metrics whose curvature is not integrable.
查看更多>>摘要：We consider the Bouw-Möller surfaces with two parameters m,n when they are not both even or m=n,n is even.We computer the e-Minkowski constant of them.
查看更多>>摘要：In this paper,we revisit the Kähler structures on the affine quadrics M1={z12+z22+z23=1} in the paper by Bo Yang and Fang-Yang Zheng.We found that the Kähler structures on the complex surface are more complicated than what they have thought.We shall also give some detail calculations and found that our results fit quite well with earlier papers of the first author,one of them with X.X.Chen.
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