Contribution à l'étude des mécanismes réactionnels dans l'azote activé

Contribution à l'étude des mécanismes réactionnels dans l'azote activé PDF Author: Brigitte Mutel
Publisher:
ISBN:
Category :
Languages : fr
Pages : 264

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Book Description
Etude expérimentale de la réaction entre n::(2)* et co par spectrométries visible et rpe en fonction de différents facteurs. Mise en évidence d'un effet de long contact , différent suivant que la réaction se produit en phase homogène ou hétérogène. Rôle fondamental de n::(2)(x**(1)sigma ::(g)**(+),v') dans cette réaction. Evolution cinétique de cet effet de long contact, qui résulterait de la superposition de deux mécanismes; 1) un mécanisme homogène proportionnel a la teneur du mélange réactif en co (exaltation de la concentration d'atomes n(**(4)s) et de n::(2)(b**(3)pi ::(g))), indépendant du temps de contact, et 2) un mécanisme héterogene du a des traces de co, qui dépend principalement de l'état de paroi du réacteur, caractérise par des centres actifs capables de fixer co, n::(2) et ces molécules vibrationnellement excitées

Contribution à l'étude des mécanismes réactionnels dans l'azote activé

Contribution à l'étude des mécanismes réactionnels dans l'azote activé PDF Author: Brigitte Mutel
Publisher:
ISBN:
Category :
Languages : fr
Pages : 264

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Book Description
Etude expérimentale de la réaction entre n::(2)* et co par spectrométries visible et rpe en fonction de différents facteurs. Mise en évidence d'un effet de long contact , différent suivant que la réaction se produit en phase homogène ou hétérogène. Rôle fondamental de n::(2)(x**(1)sigma ::(g)**(+),v') dans cette réaction. Evolution cinétique de cet effet de long contact, qui résulterait de la superposition de deux mécanismes; 1) un mécanisme homogène proportionnel a la teneur du mélange réactif en co (exaltation de la concentration d'atomes n(**(4)s) et de n::(2)(b**(3)pi ::(g))), indépendant du temps de contact, et 2) un mécanisme héterogene du a des traces de co, qui dépend principalement de l'état de paroi du réacteur, caractérise par des centres actifs capables de fixer co, n::(2) et ces molécules vibrationnellement excitées

CONTRIBUTION A L'ETUDE DE L'ACTIVATION DE L'AZOTE PAR LES COMPLEXES DU MOLYBDENE

CONTRIBUTION A L'ETUDE DE L'ACTIVATION DE L'AZOTE PAR LES COMPLEXES DU MOLYBDENE PDF Author: C.. MINISCLOUX
Publisher:
ISBN:
Category :
Languages : fr
Pages : 28

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Book Description
MISE EN EVIDENCE DE COMPLEXES OU L'AZOTE EST SIMPLEMENT COORDINE AU MO ET DES COMPOSES ULTIMES (LES NITRURES) DE LA REACTION DE L'AZOTE AVEC LES SELS DE MO

Alkene Polymerization Reactions with Transition Metal Catalysts

Alkene Polymerization Reactions with Transition Metal Catalysts PDF Author: Yury Kissin
Publisher: Elsevier
ISBN: 0080557996
Category : Technology & Engineering
Languages : en
Pages : 607

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Book Description
During the past 30 years, the field of alkene polymerization over transition metal catalysts underwent several major changes:1. The list of commercial heterogeneous Ziegler-Natta catalysts for the synthesis of polyethylene and stereoregular polyolefins was completely renewed affording an unprecedented degree of control over the polymer structure.2. Research devoted to metallocene and other soluble transition-metal catalysis has vastly expanded and has shifted toward complexes of transition metals with multidentate ligands.3. Recent developments in gel permeation chromatography, temperature-rising fractionation, and crystallization fractionation provided the first reliable information about differences between various active centers in transition-metal catalysts.4. A rapid development of high-resolution 13C NMR spectroscopy resulted in greatly expanded understanding of the chemical and steric features of polyolefins and alkene copolymers. These developments require a new review of all aspects of alkene polymerization reactions with transition-metal catalysts. The first chapter in the book is an introductory text for researchers who are entering the field. It describes the basic principles of polymerization reactions with transition-metal catalysts, the types of catalysts, and commercially manufactured polyolefins. The next chapter addresses the principal issue of alkene polymerization catalysis: the existence of catalyst systems with single and multiple types of active centers. The subsequent chapters are devoted to chemistry and stereochemistry of elemental reaction steps, structures of catalyst precursors and reactions leading to the formation of active centers, kinetics of polymerization reactions, and their mechanisms.The book describes the latest commercial polymerization catalysts for the synthesis of polyethylenes and polypropylene The book provides a detailed description of the multi-center nature of commercial Ziegler-Natta catalysts. The book devotes specialized chapters to the most important aspects of transition metal polymerization catalysts: the reactions leading to the formation of active centers, the chemistry and stereochemistry of elemental polymerization steps, reaction kinetics, and the polymerization mechanism. The book contains an introductory chapter for researchers who are entering the field of polymerization catalysis. It describes the basic principles of polymerization reactions with transition-metal catalysts and the types of commercially manufactured polyolefins and copolymersThe book contains over 2000 references, the most recent up to end of 2006.

Kerogen

Kerogen PDF Author: Bernard Durand
Publisher: Editions TECHNIP
ISBN: 9782710803713
Category : Nature
Languages : en
Pages : 560

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Book Description


Nitroxides

Nitroxides PDF Author: Olivier Ouari
Publisher: Royal Society of Chemistry
ISBN: 1788019660
Category : Science
Languages : en
Pages : 611

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Book Description
Nitroxides are versatile small organic molecules possessing a stabilised free radical. With their unpaired electron spin they display a unique reactivity towards various environmental factors, enabling a diverse range of applications. They have uses as synthetic tools, such as catalysts or building blocks; imaging agents and probes in biomedicine and materials science; for medicinal antioxidant applications; and in energy storage. Polynitroxides (polymers bearing pendant nitroxide sidechains) have been used in organic radical batteries, oxidation catalysts and in exchange reactions for constructing complex architectures. Chapters in this book cover the synthesis of nitroxides, EPR studies and magnetic resonance applications, physiochemical studies, and applications including in batteries, imaging and organic synthesis. With contributions from leaders in the field, Nitroxides will be of interest to graduate students and researchers across chemistry, physics, biology and materials science.

Nitroxide Spin Labels

Nitroxide Spin Labels PDF Author: Nickolai Kocherginsky
Publisher: CRC Press
ISBN: 9780849342042
Category : Science
Languages : en
Pages : 286

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Book Description
Extending the use of nitroxides as probes into more complex systems such as viable cells and whole animals requires greater knowledge of their interactions in functioning biological systems and appropriate model systems. Nitroxide Spin Labels: Reactions in Biology and Chemistry presents information essential for research in this area. Nitroxide research offers the promise of important new ways of measuring metabolism and will be useful in the diagnosis of important disease categories such as cancer, inflammation, and ischemia.

Model Cellulosic Surfaces

Model Cellulosic Surfaces PDF Author: Maren Roman
Publisher: OUP USA
ISBN: 9780841269651
Category : Science
Languages : en
Pages : 0

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Book Description
This book provides an overview of the different methods of model cellulosic surface preparation and presents recent studies on the properties of these surfaces. The topics covered are considered relatively new and would serve as the launch pad for further research in this area.

Chemical Analysis

Chemical Analysis PDF Author: Francis Rouessac
Publisher: John Wiley & Sons
ISBN: 1118681878
Category : Science
Languages : en
Pages : 494

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Book Description
Completely revised and updated, Chemical Analysis: Second Edition is an essential introduction to a wide range of analytical techniques and instruments. Assuming little in the way of prior knowledge, this text carefully guides the reader through the more widely used and important techniques, whilst avoiding excessive technical detail. Provides a thorough introduction to a wide range of the most important and widely used instrumental techniques Maintains a careful balance between depth and breadth of coverage Includes examples, problems and their solutions Includes coverage of latest developments including supercritical fluid chromatography and capillary electrophoresis

An Introduction to Differential Manifolds

An Introduction to Differential Manifolds PDF Author: Jacques Lafontaine
Publisher: Springer
ISBN: 3319207350
Category : Mathematics
Languages : en
Pages : 408

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Book Description
This book is an introduction to differential manifolds. It gives solid preliminaries for more advanced topics: Riemannian manifolds, differential topology, Lie theory. It presupposes little background: the reader is only expected to master basic differential calculus, and a little point-set topology. The book covers the main topics of differential geometry: manifolds, tangent space, vector fields, differential forms, Lie groups, and a few more sophisticated topics such as de Rham cohomology, degree theory and the Gauss-Bonnet theorem for surfaces. Its ambition is to give solid foundations. In particular, the introduction of “abstract” notions such as manifolds or differential forms is motivated via questions and examples from mathematics or theoretical physics. More than 150 exercises, some of them easy and classical, some others more sophisticated, will help the beginner as well as the more expert reader. Solutions are provided for most of them. The book should be of interest to various readers: undergraduate and graduate students for a first contact to differential manifolds, mathematicians from other fields and physicists who wish to acquire some feeling about this beautiful theory. The original French text Introduction aux variétés différentielles has been a best-seller in its category in France for many years. Jacques Lafontaine was successively assistant Professor at Paris Diderot University and Professor at the University of Montpellier, where he is presently emeritus. His main research interests are Riemannian and pseudo-Riemannian geometry, including some aspects of mathematical relativity. Besides his personal research articles, he was involved in several textbooks and research monographs.

Aeronomy

Aeronomy PDF Author: P. M. Banks
Publisher: Elsevier
ISBN: 1483260666
Category : Science
Languages : en
Pages : 445

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Book Description
Aeronomy, Part A is an attempt to make a comprehensive exposition of the processes in aeronomy, the study of composition, movement, and thermal balance of the upper regions of the planetary atmosphere. The text covers topics such as atmospheric regions and atmospheric density, the temperature and molecular mass of the atmosphere; the permanent constituents and the molecular and isotonic composition of the homosphere; and the transition from the homosphere to the heterosphere. Also covered are topics such as the temperature gradient and energies in the thermosphere, conditions at 200km and above 250km, solar radiation and ionization, and aeronomic reactions. The book is recommended for scientists, especially natural physicists, who would like to know more about the field of aeronomy and its advances.