Let (M, g(t)) be a compact Riemannian manifold and the metric g(t) evolve by the Ricci flow. In the paper we derive the evolution equation for a geometric constant lambda under the Ricci flow and the normalized Ricci flow, such that there exist positive solutions to the nonlinear equation -Delta(phi)f + af ln f + bRf = lambda f, where Delta(phi) f is the Witten-Laplacian operator, phi is an element of C-infinity(M), a and b are both real constants, and R is the scalar curvature with respect to the metric g(t). As an application, we obtain the monotonicity of the geometric constant along the Ricci flow coupled to a heat equation for manifoldM with some Ricci curvature condition when b > 1/4.

论文在田野调查的基础上,从历史人类学的角度着重考察藏族移民在美国生存发展过程中出现的新变化、新趋势.过去七十多年间,美国藏族移民不仅人口持续增加,生活状况有所改善,而且在整体发展上出现了诸多新情况、新特点:一方面民族特征日渐淡化,大有被美国主流文化完全同化之势;另一方面群体内部四分五裂、纷争不断,有些甚至发展到针锋相对、势不两立的地步.与此同时,藏族移民普遍信仰的藏传佛教也已严重异化,或被当作实现政治野心的工具,或被用于经营谋利乃至敛聚钱财,或被"改造"得面目全非,成为西方化的"美国佛教".未来相当长的时间内,融入与同化、团结与分化、信仰传承与宗教异化的矛盾都将是美国藏族移民群体必须面对的一个问题.

目的 应用同位素标记相对和绝对定量技术筛选47,XYY血清样本差异蛋白质生物标志物.方法 采集血清,提取蛋白,应用iTRAQ标记和Protein Pilot搜库,确定差异蛋白.结果 与对照组相比,实验组中共鉴定出有定量信息的蛋白质106个,其中差异有统计学意义的差异蛋白有15个,包括10个上调蛋白和5个下调蛋白.其中β-肌动蛋白上调明显,高达6倍.结论 血红蛋白β亚基、β-肌动蛋白等显著差异蛋白可能作为该病潜在的临床筛查生物标志物.

We show that a complete minimal hypersurface M in \({\mathbb{R}^{n+1}}\) (n ≥ 3) admits no nontrivial L 2 harmonic 2-form if the total curvature is bounded above by a constant depending only on the dimension of M. This result is a generalized version of the results of Cheng etc on L 2 harmonic 1-forms.

Abstract Let (M, g(t)) be a compact Riemannian manifold and the metric g(t) evolve by the Ricci flow. In the paper, we prove that the eigenvalues of geometric operator −Δφ + $\frac{R}{2}$ are non-decreasing under the Ricci flow for manifold M with some curvature conditions, where Δφ is the Witten Laplacian operator, φ ∈ C 2(M), and R is the scalar curvature with respect to the metric g(t). We also derive the evolution of eigenvalues under the normalized Ricci flow. As a consequence, we show that compact steady Ricci breather with these curvature conditions must be trivial.

自西藏叛乱至今,海外藏胞一直是我国党和政府较为重视的一个特殊群体.在过去近60年的时间内,经过三个阶段的从国内藏区向外迁移,海外藏胞的总量有了较大幅度的增长.同时,随着海外藏胞持续不断的再迁移,其分布范围也由早期的南亚四国扩展到全球40多个国家和地区.而在另一方面,改革开放后,海外藏胞归国探亲、参观乃至定居逐渐形成一种潮流.当前,海外藏胞群体正面临着许多不确定因素,随时可能再次出现较大规模的跨境迁移,他们的未来走向尤为值得关注.本文利用从印度外交部档案、联合国难民署档案等文献中发掘的新材料,详细梳理了海外藏胞跨境迁移的总体历程,并对海外藏胞的未来走向作出了相应的判断.

In this paper, we consider decompositions of basic degree 2 cohomology for a compact K-contact 5-manifold $${(M,\xi,\eta,\Phi,g)}$$ , and conclude the pureness and fullness of $${\Phi}$$ -invariant and $${\Phi}$$ -anti-invariant cohomology groups. Moreover, we discuss the decomposition of the complexified basic degree 2 cohomology group. This is an analogue problem when Draghici et al. (Int. Math. Res. Not. IMRN 1:1–17, 2010) considered the $${C^{\infty}}$$ pureness and fullness of $${J}$$ -invariant and $${J}$$ -anti-invariant subgroups of the degree 2 real cohomology group $${H^2(M,\mathbb{R})}$$ of any compact almost complex manifold $${(M, J)}$$ .

We study complete noncompact 1-minimal stable hypersurfaces in a 4-dimensional sphere S~4.We show that there is no complete noncompact 1-minimal stable hypersurfaces in S~4 with polynomial volume growth and the restriction of the mean curvature and GaussKronecker curvature.These results are partial answers to the conjecture of Alencar,do Carmo and Elbert when the ambient space is a 4-dimensional sphere.

In the paper we first derive the evolution equation for eigenvalues of geometric operator \(-\Delta _{\phi }+cR\) under the Ricci flow and the normalized Ricci flow on a closed Riemannian manifold M, where \(\Delta _{\phi }\) is the Witten–Laplacian operator, \(\phi \in C^{\infty }(M)\), and R is the scalar curvature. We then prove that the first eigenvalue of the geometric operator is nondecreasing along the Ricci flow on closed surfaces with certain curvature conditions when \(0<c\le \frac{1}{2}\). As an application, we obtain some monotonicity formulae and estimates for the first eigenvalue on closed surfaces.

In this paper, we prove that the dimension of the second space of reduced L2 cohomology of M is finite if is a complete noncompact hypersurface in a sphere 𝕊n+1and has finite total curvature (n≥3).

Let (M, g(t)) be a compact Riemannian manifold and the metric g(t) evolve by the Ricci flow. We derive the evolution equation for the eigenvalues of geometric operator −Δ ϕ + cR under the Ricci flow and the normalized Ricci flow, where Δ ϕ is the Witten-Laplacian operator, ϕ ∈ C ∞(M), and R is the scalar curvature with respect to the metric g(t). As an application, we prove that the eigenvalues of the geometric operator are nondecreasing along the Ricci flow coupled to a heat equation for manifold M with some Ricci curvature condition when \(c > \tfrac{1}{4}\).

Based on recent work of T. Draghici, T.-J. Li, and W. Zhang, we further investigate properties of the dimension h(J)(-) of the J-anti-invariant cohomology subgroup H-J(-) of a closed almost Hermitian 4-manifold (M, g, J, F) using metric compatible almost complex structures. We prove that h(J)(-) = 0 for generic almost complex structures J on M.

We study a complete noncompact minimal submanifold M n in a sphere S n+p . We prove there is no nontrivial L 2 harmonic 1-form and at most one nonparabolic end on M if the total curvature is bounded from above by a constant depending only on n. The rigidity theorem is a generalized version of Ni’s, Yun’s and the second author’s results on submanifolds in Euclidean spaces and Seo’s result on minimal submanifolds in hyperbolic spaces.

随着科技与经济社会发展所面临问题的日益复杂化、巨型化、综合化,高校传统的科研组织模式已越来越难以适应时代需求,实施协同创新势在必行.但是,如何将高校、科研院所、行业企业、地方政府等不同性质的社会组织有效协同起来,以最优化的模式实施创新,是在协同创新框架下开展科学研究首先必须解决的问题.有鉴于此,当前迫切需要根据协同创新的自组织特性,按照开放、共享、问题导向、分工协作的原则,重新设计科研组织,并建立相应的运行机制.

In this paper, we investigate the relationship between J-anti-invariant cohomology of a closed symplectic 4-manifold introduced by T.-J. Li and W. Zhang and new symplectic cohomologies introduced by L.-S. Tseng and S.-T. Yau. We also prove that the dimension of J-anti-invariant cohomology is constant for almost structures J which are compatible with a fixed symplectic form.

In this paper, we obtain vanishing theorems and finitely many ends theorems of complete Riemannian manifolds with weighted Poincaré inequality, applying them to minimal hypersurfaces.

协同创新中心是实施"2011计划"的重要载体,也是包括多种利益相关者的利益共同体。然而,由于组织管理方式尚不成熟,目前大部分协同创新中心的运行效果并不理想。为此,有必要从利益相关者的角度出发,按照多元开放、互利共赢、多中心治理和柔性化的原则,建立科学合理的分工机制、沟通协调机制与利益分配机制,完善协同创新中心的组织管理体系,促进协同创新中心高效运行和可持续发展。

华侨华人研究是暨南大学重要的学术传统和特色.“高等学校创新能力提升计划”启动实施后,暨南大学紧抓机遇,牵头组建了华侨华人研究协同创新中心.该中心以华侨华人在中国和平发展中的作用这一重大战略性需求为导向,以涉侨研究与运用的机制体制改革为核心,选取了六大重点发展方向,在华侨华人研究创新能力提升方面做出了积极探索.

协同创新中心是"2011计划"的重要载体,也是包括多种利益相关者的创新共同体。然而,由于评价制度及其相关的机制体制改革滞后,致使大部分协同创新中心的运行效果并不理想。为此,有必要从利益相关者的角度出发,按照以创新质量和贡献为导向、社会效益与经济效益相结合、内部评价与外部评价相结合、统一标准与分类评价相结合、奖惩性评价与发展性评价相结合的原则,构建科学合理的评价体系,促进协同创新中心高效运行和可持续发展。