Search results for "foliation"

Minimal models of foliated algebraic surfaces

1999

MODELES MINIMAUX DES SURFACES ALGEBRIQUES FEUILLETEES. -Nous etudions les feuilletages holomorphes sur les surfaces algebriques du point de vue de la geometrie birationnelle. Apres avoir introduit une notion de modele minimal, nous classifions les feuilletages qui n'ont pas de modele minimal dans leur classe d'isomorphisme birationnel. Comme corollaire on obtient un resultat concernant la dynamique des diffeomorphismes polynomiaux.

Substrate impact on the thickness dependence of vibrational and optical properties of large area $MoS_2$ produced by gold-assisted exfoliation

2021

The gold-assisted exfoliation is a very effective method to produce large-area ($cm^2$-scale) membranes of molybdenum disulfide ($MoS_2$) for electronics. However, the strong $MoS_2/Au$ interaction, beneficial for the exfoliation process, has a strong impact on the vibrational and light emission properties of $MoS_2$. Here, we report an atomic force microscopy (AFM), micro-Raman ($\mu-R$) and micro-Photoluminescence ($\mu-PL$) investigation of $MoS_2$ with variable thickness exfoliated on Au and subsequently transferred on an $Al_2O_3/Si$ substrate. The $E_{2g}$ - $A_{1g}$ vibrational modes separation $\Delta\mu$ (typically used to estimate $MoS_2$ thickness) exhibits an anomalous large val…

Invasive and native populations of common ragweed exhibit strong tolerance to foliar damage.

2013

8 pages; International audience; Tolerance and resistance are defence strategies evolved by plants to cope with damage due to herbivores. The introduction of exotic species to a new biogeographical range may alter the plant herbivore interactions and induce selection pressures for new plant defence strategies with a modified resource allocation. To detect evolution in tolerance to herbivory in common ragweed, we compared 3 native (North America) and 3 introduced (France) populations, grown in a common garden environment. We explored the effect of leaf herbivory on plant vegetative and reproductive traits. Plants were defoliated by hand, simulating different degrees of insect grazing by remo…

Some Special Foliations

2014

In this chapter we study two classes of ubiquitous foliations: Riccati foliations and turbulent foliations. A section will also be devoted to a very special foliation, which will play an important role in the minimal model theory.

Time Markers for the Evolution and Exhumation History of a Late Palaeozoic Paired Metamorphic Belt in North-Central Chile (34°-35°30'S)

2005

A multi-method geochronological approach is applied to unravel the dynamics of a paired metamorphic belt in the Coastal Cordillera of central Chile. This is represented by high-pressure - low-temperature rocks of an accretionary prism (Western Series), and a low-pressure- high-temperature overprint in the retro-wedge with less deformed metagreywackes (Eastern Series) intruded by magmas of the coeval arc. A pervasive transposition foliation formed in metagreywackes and interlayered oceanic crust of the Western Series during basal accretion near metamorphic peak conditions (∼350-400°C, 7-11 kbar) at 292-319 Ma (

EFFECT OF ARTIFICIAL SHADING ON POLYPHENOLIC ACCUMULATION AND AROMATIC COMPOSITION OF GRILLO CV (VITIS VINIFERA L.)

2011

Curves as measured foliation on noncompact surfaces

1993

In the present work, that regards the Thurston's theory, we prove that, if we choose a closed curve, how we wish, on a noncompact surface, it is always possible to construct a particular masured foliation that has the choosed curve like a leaf; we also prove this foliation has a remarkable property that makes very easy to mesure all homotopy classes of closed curves of our surface. To prove this statement we need some Propositions and some Lemma that we also demonstre.

From Layered Molybdic Acid to Lower-Dimensional Nanostructures by Intercalation of Amines under Ambient Conditions

2006

Nanostructures of varied dimensionality such as rods, scrolls, and disks of molybdenum oxide have been synthesized in gram quantities under ambient conditions using exfoliation of the layers as a synthetic tool. Intercalation of alkylamines (CnH2n+2NH2, where n = 3, 4, 8, 12, and 16) into yellow molybdic acid (MoO3·2H2O) and subsequent treatment with nitric acid resulted in molybdenum oxide nanorods, nanodisks, or oxide−amine composite nanorods. The sizes of the nanoparticles range from a few nanometers to micrometers in length and 10 to 200 nm in diameter. Detailed X-ray, scanning electron microscopy, and transmission electron microscopy analyses reveal an inverse relation between the size…

Invariants of transverse foliations

2012

Abstract We construct two invariants for a pair of transverse one-dimensional foliations on the plane. If the set of separatrices is Hausdorff in the space of leaves, the invariant is a distinguished graph. In case there are a finite number of separatrices the invariant is an indexed link.

Foliations of $\mathbb{S}^3$ by Cyclides

2018

Throughout the last 2–3 decades, there has been great interest in the extrinsic geometry of foliated Riemannian manifolds (see [2], [4] and [22]). ¶One approach is to build examples of foliations with reasonably simple singularities with leaves admitting some very restrictive geometric condition. For example (see [22], [23] and [17]), consider in particular foliations of $\mathbb{S}^{3}$ by totally geodesic or totally umbilical leaves with isolated singularities. ¶The article [14] provides families of foliations of $\mathbb{S}^{3}$ by Dupin cyclides with only one smooth curve of singularities. Quadrics and other families of cyclides like Darboux cyclides provide other examples. These foliat…