法国会计环境与会计模式对中国会计变革的启示

随着全球经济一体化和会计国际化发展，国际会计问题成为各国关注的焦点。欧盟是中国的主要贸易伙伴，而法国又是欧盟的核心成员，法国独有的私人工商企业体制与民族文化环境，形成了拉丁会计的稳健与保守的会计模式。研究和借鉴法国会计发展之中的可取之处，有利于我国会计的国际化进程，从而谋求最大国家利益，对我国会计变革有所启示。     

Strengthening the Murty–Simon conjecture on diameter 2 critical graphs

A graph is diameter-2-critical if its diameter is 2 but the removal of any edge increases the diameter. A well-studied conjecture, known as the Murty–Simon conjecture, states that any diameter-2-critical graph of order $n$ has at most $?n^2∕4?$ edges, with equality if and only if $G$ is a balanced complete bipartite graph. Many partial results about this conjecture have been obtained, in particular it is known to hold for all sufficiently large graphs, for all triangle-free graphs, and for all graphs with a dominating edge. In this paper, we discuss ways in which this conjecture can be strengthened. Extending previous conjectures in this direction, we conjecture that, when we exclude the class of complete bipartite graphs and one particular graph, the maximum number of edges of a diameter-2-critical graph is at most $?{(n?1)}^2∕4?+1$. The family of extremal examples is conjectured to consist of certain twin-expansions of the 5-cycle (with the exception of a set of thirteen special small graphs). Our main result is a step towards our conjecture: we show that the Murty–Simon bound is not tight for non-bipartite diameter-2-critical graphs that have a dominating edge, as they have at most $?n^2∕4??2$ edges. Along the way, we give a shorter proof of the Murty–Simon conjecture for this class of graphs, and stronger bounds for more specific cases. We also characterize diameter-2-critical graphs of order $n$ with maximum degree $n?2$: they form an interesting family of graphs with a dominating edge and $2n?4$ edges.     

Functionalization of 2D materials by intercalation

Since the discovery of graphene many studies focused on its functionalization by different methods. These strategies aim to find new pathways to overcome the main drawback of graphene, a missing band-gap, which strongly reduces its potential applications, particularly in the domain of nanoelectronics, despite its huge and unequaled charge carrier mobility. The necessity to contact this material with a metal has motivated a lot of studies of metal/graphene interactions and has led to the discovery of the intercalation process very early in the history of graphene. Intercalation, where the deposited atoms do not stay at the graphene surface but intercalate between the top layer and the substrate, may happen at room temperature or be induced by annealing, depending of the chemical nature of the metal. This kind of mechanism was already well-known in the earlier Graphite Intercalation Compounds (GICs), particularly famous for one current application, the Lithium-ion Battery, which is simply an application based on the intercalation of Lithium atoms between two sheets of graphene in a graphite anode. Among numerous discoveries the GICs community also found a way to obtain graphite with superconducting properties by using intercalated alkali metals. Graphene is now a playground to “revisit” and understand all these mechanisms and to discover possible new properties of graphene induced by intercalation. For example, the intercalation process may be used to decouple the graphene layer from its substrate, to change its doping level or even, in a more general way, to modify its electronic band structure and the nature of its Dirac fermions. In this paper we will focus on the functionalization of graphene by using intercalation of metal atoms but also of molecules. We will give an overview of the induced modifications of the electronic band structure possibly leading to spin-orbit coupling, superconductivity, …We will see how this concept of functionalization is also now used in the framework of other 2D materials beyond graphene and of van der Waals heterostructures based on these materials.     

Metalation reactions : VI. Metalation of substituted ferrocenes with methylpentacarbonyl-manganese and -rhenium; formation of homoannular metalated ferrocenes and of the novel ferrocenylmethyl(methyl)aminomethylenetetracarbonylmanganese

The isolation and characterization of tetracarbonyl-2-(acetyl)ferrocenylrhenium and tetracarbonyl-2-(acetyl)ferrocenylmanganese from the reaction of acetylferrocene with methylpentacarbonylrhenium (Ia) and -manganese (Ib) respectively, are reported. In addition tetracarbonyl-2-(dimethylaminomethyl)ferrocenylrhenium has been prepared from dimethylaminomethylferrocene (IV) and Ia, but treatment of IV with Ib results in formation of the novel ferrocenylmethyl(methyl)aminomethylenetetracarbonylmanganese.     

Calcul de l'emission infrarouge de milieux laser CO2

Vibrationally-excited CO₂ present with inverted population emits infrared radiation at 4·26 μm. For an emitter consisting of optically-thick isolated lines, calculations allow determination of the emissivity and radiancy of a homogeneous layer of gas. Infrared emission is a useful tool for measurement of the energy contained in the upper laser level. A very thin layer of cold gas strongly alters the spectral distribution of the intensity and causes the total radiancy to decrease.     

Dilatometric study of β-alumina single crystals

Single crystals of β-alumina exhibit an important dilatometric anisotropy. The anisotropic factor is about three for βNa-alumina. Variations of this factor are followed according to the nature of the conducting ion and the stoichiometry. The dilatometric behaviour of these compounds is explained (up to 800°C) from previous structural results.     

Transport processes in NaCl single crystals doped with a trivalent cation; solubility,association and migration of Y3+

The self-diffusion coefficient of ²²Na⁺ and the ionic conductivity are measured as a function of temperature in NaCl single crystals doped with labelled yttrium ions, as well as the diffusion coefficient of ⁸⁸Y³⁺. We give the theoretical equations for the transport processes in the alkali halides doped with a trivalent cation; These are derived from the theory of the crystals doped with divalent cations. Solubility of YCl₃ in NaCl is accurately determined through a radioactive technique. The free enthalpy of solubility of free Y³⁺ is: (2.91?13 kT) eV. A good fit of the whole set of data is obtained by treating the association between Y³⁺ ions and vacancies by the single equation $\text{K}{}_2\text{= 12}\text{exp}\text{(-9.5)}\text{exp}\text{(}\text{1.17}\text{kT}\text{)}$. The jump frequency of Y³⁺ is $\text{w}{}_2\text{= 1.37 × 10}{}^{13}\text{exp}\text{(-}\text{0.98}\text{kT}\text{)}\text{sec}{}^{-1}$. The results are compared to those characterising the divalent foreign cations.     

How does geographical distance translate into genetic distance?

Geographic structure can affect patterns of genetic differentiation and speciation rates. In this article, we investigate the dynamics of genetic distances in a geographically structured metapopulation. We model the metapopulation as a weighted directed graph, with $d$ vertices corresponding to $d$ subpopulations that evolve according to an individual based model. The dynamics of the genetic distances is then controlled by two types of transitions — mutation and migration events. We show that, under a rare mutation–rare migration regime, intra subpopulation diversity can be neglected and our model can be approximated by a population based model. We show that under a large population-large number of loci limit, the genetic distance between two subpopulations converges to a deterministic quantity that can asymptotically be expressed in terms of the hitting time between two random walks in the metapopulation graph. Our result shows that the genetic distance between two subpopulations does not only depend on the direct migration rates between them but on the whole metapopulation structure.     

大革命前（1661～1789）法国社会状况的特点及启示

法国大革命前,法国曾在路易十四时期经历了称霸欧陆的辉煌,对内发展工商业,对外开疆扩土,波旁王朝的势力遍及整个欧洲,法国资本主义迅速发展,国内财富迅速增加.然而,经济发展的同时,由于政治体制的腐朽,社会阶层的分化,社会分配的不公,法国的社会状况日益恶化,社会矛盾日益激发,再加上路易十五对外作战不利,欧洲诸国敌视法国,内外矛盾交加之下,启蒙运动又为法国人民指明了革命的方向,所以在诸多因素的综合作用下,波旁王朝迅速由鼎盛走向崩溃.     

法国医学教育制度分析及其启示

通过对法国医学教育概况的介绍,展示其分阶段教育的特点,并详细说明了其课程设置。结合法国的教育制度,分析了其对医学生培训过程中注重理论课程的综合性、理论教学与临床实践合理结合、安排大量见习实习及鼓励学生自主学习的特点。法国对临床医生的培养还具有国家统筹规划、重视全科医学、不断进行改革等优点。最后提出了我国的临床医学专业教育中,在课程改革、培养模式、住院医师培训制度中可以借鉴改进之处。