Une remarque sur l'orthogonalité de l'image au noyau d'une dérivation généralisée

In this paper we introduce the notion of the pair of operators having the Fuglede-Putnam property in a two-sided ideal of . The characterization of this class allows us to generalize the recent result of F. Kittaneh. We also give some applications of this result.

     

On the measure theoretic structure of compact groups

If is a compact group with , we show the following results:

(i)

There exist direct products of compact metric groups and continuous open surjections with respect to Haar measure; and

(ii)

the Haar measure on is Baire and at the same time Jordan isomorphic to the Haar measure on a direct product of compact Lie groups.

Applications of the above results in measure theory are given.

     

合成低碳混合醇耐硫催化剂MoS_2/K_2CO_3/γ-Al_2O_3制备的新方法

根据单层分散原理,设计了制备单层(或亚单层)分散型的合成低碳混合醇耐硫催化剂MoS_2/K_2CO_3/γ-Al_2O_3的新方法:先把比MoS_2易于分散的MoO_3分散到γ-Al_2O_3表面上形成单层或亚单层分散的MoO_3/γ-Al_2O_3母体,再进行硫化/还原,最后添加K_2CO_3。CO加氢反应结果证实:(1)该催化剂具有良好的抗硫性能;(2)以单个Mo原子计的活性较非单层(或亚单层)分散型的催化剂的活性成倍增加;(3)使低碳混合醇中C_2~+OH的含量增加,更符合作为汽油添加燃料的要求。     

煤基富勒烯烟灰萃取产物的质谱分析

用甲苯等有机溶剂对由煤制得烟灰(soot)进行索氏萃取，用时间飞行质谱及气相色谱-质谱联用（GCMS）技术对所得的萃取产物进行了分析，结果发现，煤基粗富勒烯中除含有大量的C60和C70外，高碳富勒烯（如C74、C78，C82、C84、C100及C106等）的丰度也较高。在煤基粗富勒烯的伴生副产物中存在一些含有苯环结构的芳香性碳氢化合物和少量的长烷烃化合物，由此推测煤基富勒烯的形成过程可能遵循着一条与以石墨为原料时的机制完全不同的途径。     

Preparation and crystal structure of C84(11)Cl20,22, chloro derivatives of a C84 minor isomer

Chlorofullerenes C₈₄(11)Cl₂₀ and C₈₄(11)Cl₂₂ were prepared by chlorination of C₂–C₈₄(11) with VCl₄ at 340–360 °C. An X-ray crystallographic study with the use of synchrotron radiation revealed the chlorination patterns featuring only para additions in C₆Cl₂ hexagons.     

Absolute Valued Strongly Power-Associative Triple Systems

Absolute valued triple system are the natural ternary extension of absolute valued algebras. In this article we classify strongly power-associative absolute valued triple systems.     

Intrinsic expression of the derivatives in domain optimization problems

It is well-known in domain optimization that the derivative of a cost function with respect to the shape of a domain is a distribution with support lying in the boundary of the domain to be optimized. This existence result is completed with a constructive method giving an explicit expression of this distribution, which can be applied in general cases. The relationship between material and local derivates of any order, provided they are well-defined, is also investigated.     

Jordan Superhomomorphisms of Superalgebras

The aim of this article is to investigate Jordan superhomomorphisms of superalgebras (with and without superinvolution), using the theory of functional identities in superalgebras. As a consequence we slightly improve a result on Jordan homomorphisms of rings with involution.     

Higher‐order and adaptive discontinuous Galerkin methods with shock‐capturing applied to transonic turbulent delta wing flow

Discontinuous Galerkin (DG) methods allow high‐order flow solutions on unstructured or locally refined meshes by increasing the polynomial degree and using curved instead of straight‐sided elements. DG discretizations with higher polynomial degrees must, however, be stabilized in the vicinity of discontinuities of flow solutions such as shocks. In this article, we device a consistent shock‐capturing method for the Reynolds‐averaged Navier–Stokes and k‐ ω turbulence model equations based on an artificial viscosity term that depends on element residual terms. Furthermore, the DG method is combined with a residual‐based adaptation algorithm that targets at resolving all flow features. The higher‐order and adaptive DG method is applied to a fully turbulent transonic flow around the second Vortex Flow Experiment (VFE‐2) configuration with a good resolution of the vortex system.Copyright © 2013 John Wiley & Sons, Ltd.     

Osculating properties of decomposable scrolls

Osculating spaces of decomposable scrolls (of any genus and not necessarily normal) are studied and their inflectional loci are related to those of their generating curves by using systematically an idea introduced by Piene and Sacchiero in the setting of rational normal scrolls. In this broader setting the extra components of the second discriminant locus – deriving from flexes – are investigated and a new class of uninflected surface scrolls is presented and characterized. Further properties related to osculation are discussed for (not necessarily decomposable) scrolls (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)