一类拟线性奇摄动边值问题的激波性态(英文)

The existence and asymptotic behavior of solution for a class of quasilinear singularly perturbed boundary value problems are discussed under suitable conditions by the theory of differential inequalities and matching principle.     

Flexible incomplete Cholesky factorization with multi‐parameters to control the number of nonzero elements in preconditioners

An incomplete Cholesky (IC) factorization with multi‐parameters is presented. The marked virtue of the proposed IC factorization algorithm is to dynamically control the number of nonzero elements in each column of the IC factorization preconditioner L with the help of these involved parameters. Parameter setting strategies are also given. Numerical results show that the total computing time for both computation of the preconditioner L and iterative solution is evidently reduced for almost all test matrices. In general, these parameters can obviously enhance the effectiveness and performance of the IC factorization. Copyright © 2011 John Wiley & Sons, Ltd.     

The structure on invariant measures of <Emphasis Type="Italic">C</Emphasis><Superscript>1</Superscript> generic diffeomorphisms

Let Λ be an isolated non-trivial transitive set of a C 1 generic diffeomorphism f ∈ Diff (M ). We show that the space of invariant measures supported on Λ coincides with the space of accumulation measures of time averages on one orbit. Moreover, the set of points having this property is residual in Λ (which implies that the set of irregular+ points is also residual in Λ). As an application, we show that the non-uniform hyperbolicity of irregular+ points in Λ with totally 0 measure (resp., the non-uniform hyperbolicity of a generic subset in Λ) determines the uniform hyperbolicity of Λ.     

Two New Types of Conserved Quantities Deduced from Noether Symmetry for Nonholonomic Mechanical System

For a nonholonomic mechanical system, the generalized Mei conserved quantity and the new generalized Hojman conserved quantity deduced from Noether symmetry of the system are studied. The criterion equation of the Noether symmetry for the system is got. The conditions under which the Noether symmetry can lead to the two new conserved quantities are presented and the forms of the conserved quantities are obtained. Finally, an example is given to illustrate the application of the results.     

Perturbation to Unified Symmetry and Adiabatic Invariants for Relativistic Hamilton Systems

Based on the concept of adiabatic invariant, the perturbation to unified symmetry and adiabatic invariants for relativistic Hamilton systems are studied. The definition of the perturbation to unified symmetry for the system is presented, and the criterion of the perturbation to unified symmetry is given. Meanwhile, the Noether adiabatic invariants, the generalized Hojman adiabatic invariants, and the Mei adiabatic invariants for the perturbed system are obtained.     

Perturbation to Lie-Mei Symmetry and Adiabatic Invariants for Birkhoffian Systems

Based on the concept of adiabatic invariant, the perturbation to Lie-Mei symmetry and adiabatic invariants for Birkhoffian systems are studied. The definition of the perturbation to Lie-Mei symmetry for the system is presented, and the criterion of the perturbation to Lie-Mei symmetry is given. Meanwhile, the Hojman adiabatic invariants and the Mei adiabatic invariants for the perturbed system are obtained.     

New Conserved Quantities of Noether--Mei Symmetry for Nonholonomic Mechanical System

Two new types of conserved quantities deduced by Noether-Mei symmetry of nonholonomic mechanical system are studied. The definition and criterion of Noether-Mei symmetry for the system are given. A coordination function is introduced, and the conditions under which the Noether-Mei symmetry leads to the two types of conserved quantities and the forms of the two types of conserved quantities are obtained. An illustrative example is given. The coordination function can be selected according to the demand for finding the gauge function, and the choice of the coordination function has multiformity, so more conserved quantities deduced from Noether-Mei symmetry of mechanical system can be obtained.     

N2-苯浮选缔合光度法测定碘的研究

本文依据在强酸性磷酸介质中,Br2氧化I-为I2,进而与I-生成配阴离子I-3,利用溴化十六烷基三甲胺(CTMAB)与I-3发生等离子对缔合物反应,生成缔合物CTMA+*I-3,该缔合物易溶于苯,且在苯中稳定,从而建立了溶剂浮选光度法测碘新方法.本法灵敏度高,选择性强,精密度好,实测了天然水及加碘的盐中碘,结果令人满意.     

γ-Al2O3负载Cr促进SO2-4/ZrO2固体超强酸研究

将Ｃｒ促进的ＳＯ＾２－４／ＺｒＯ２（ＳＺ）固体超强酸Ｃｒ－ＳＺ负载于γ－Ａｌ２Ｏ３载体上,制成Ｃｒ－ＳＺ／Ａｌ２Ｏ３系列固体超强酸,利用探针反应考察了其超强酸性,中强酸性和弱酸性的变化情况,详细研究了样品的比表面、硫含量、ＺｒＯ２晶化情况及正丁烷低温异构化反应活性,结果发现,负载后部分Ｃｒ－ＳＺ的正丁烷低温异构化反应活性显著提高,含铬样品酸强度和脱氢性能的增强对其正丁烷异构化反应活性的提高均有贡献,样品酸性和脱氢性之间的合适匹配使Ｃｒ－ＳＺ／Ａｌ２Ｏ３显示出很高的正丁烷异构化反应活性。     

Multinuclear Solid State NMR for the Study of Chemistry in Surface Science

This presentation will cover recent progress in the development and application of solid-state NMR techniques for characterizing surface chemistry. Several technological important systems, such as "ship-in-a-bottle" synthesis in zeolite, chemical immobilization on polymer surface and environmental pollutant-soil interactions, have been investigated by multinuclear solid- state NMR spectroscopy. An in situ sold-state NMR technique, GRASSHopper, has been introduced to study heterogeneous catalysis under flowing conditions.