The Chemical Bond

The Chemical Bond PDF
Author: Ahmed Zewail
Publisher: Elsevier
Category : Science
Languages : en
Pages : 313
View: 3814

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Book Description:
This inspired book by some of the most influential scientists of our time--including six Nobel laureates--chronicles our emerging understanding of the chemical bond through the last nine decades and into the future. From Pauling's early structural work using x-ray and electron diffraction to Zewail's femtosecond lasers that probe molecular dynamics in real time; from Crick's molecular biology to Rich's molecular recognition, this book explores a rich tradition of scientific heritage and accomplishment. The perspectives given by Pauling, Perutz, Rich, Crick, Porter, Polanyi, Herschbach, Zewail, and Bernstein celebrate major scientific achievements in chemistry and biology with the chemical bond playing a fundamental role. In a unique presentation that also provides some lively insights into the very nature of scientific thought and discovery, The Chemical Bond: Structure and Dynamics will be of general interest to scientists, science historians, and the scientifically inclined populous.


Fortschritte Der Chemie Organischer Naturstoffe

Fortschritte der Chemie Organischer Naturstoffe PDF
Author:
Publisher: Springer-Verlag
Category : Science
Languages : de
Pages : 366
View: 2804

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Book Description:
Dieser Buchtitel ist Teil des Digitalisierungsprojekts Springer Book Archives mit Publikationen, die seit den Anfängen des Verlags von 1842 erschienen sind. Der Verlag stellt mit diesem Archiv Quellen für die historische wie auch die disziplingeschichtliche Forschung zur Verfügung, die jeweils im historischen Kontext betrachtet werden müssen. Dieser Titel erschien in der Zeit vor 1945 und wird daher in seiner zeittypischen politisch-ideologischen Ausrichtung vom Verlag nicht beworben.


Tools And Modes Of Representation In The Laboratory Sciences

Tools and Modes of Representation in the Laboratory Sciences PDF
Author: U. Klein
Publisher: Springer Science & Business Media
Category : Philosophy
Languages : en
Pages : 264
View: 1485

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Book Description:
constitutive of reference in laboratory sciences as cultural sign systems and their manipulation and superposition, collectively shared classifications and associated conceptual frameworks,· and various fonns of collective action and social institutions. This raises the question of how much modes of representation, and specific types of sign systems mobilized to construct them, contribute to reference. Semioticians have argued that sign systems are not merely passive media for expressing preconceived ideas but actively contribute to meaning. Sign systems are culturally loaded with meaning stemming from previous practical applications and social traditions of applications. In new local contexts of application they not only transfer stabilized meaning but also can be used as active resources to add new significance and modify previous meaning. This view is supported by several analyses presented in this volume. Sign systems can be implemented like tools that are manipulated and superposed with other types of signs to forge new representations. The mode of representation, made possible by applying and manipulating specific types of representational tools, such as diagrammatic rather than mathematical representations, or Berzelian fonnulas rather than verbal language, contributes to meaning and forges fine-grained differentiations between scientists' concepts. Taken together, the essays contained in this volume give us a multifaceted picture of the broad variety of modes of representation in nineteenth-century and twentieth-century laboratory sciences, of the way scientists juxtaposed and integrated various representations, and of their pragmatic use as tools in scientific and industrial practice.


The Nature Of The Hydrogen Bond

The Nature of the Hydrogen Bond PDF
Author: Gastone Gilli
Publisher: OUP Oxford
Category : Science
Languages : en
Pages : 330
View: 2775

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Book Description:
Hydrogen bond (H-bond) effects are known: it makes sea water liquid, joins cellulose microfibrils in trees, shapes DNA into genes and polypeptide chains into wool, hair, muscles or enzymes. Its true nature is less known and we may still wonder why O-H...O bond energies range from less than 1 to more than 30 kcal/mol without apparent reason. This H-bond puzzle is re-examined here from its very beginning and presented as an inclusive compilation of experimental H-bond energies and geometries. New concepts emerge from this analysis: new classes of systematically strong H-bonds (CAHBs and RAHBs: charge- and resonance-assisted H-bonds); full H-bond classification in six classes (the six chemical leitmotifs); and assessment of the covalent nature of strong H-bonds. This leads to three distinct but inter-consistent models able to rationalize the H-bond and predict its strength, based on classical VB theory, matching of donor-acceptor acid-base parameters (PA or pKa), or shape of the H-bond proton-transfer pathway. Applications survey a number of systems where strong H-bonds play an important functional role, namely drug-receptor binding, enzymatic catalysis, ion-transport through cell membranes, crystal design and molecular mechanisms of functional materials.


Molek Lphysik Und Quantenchemie

Molek  lphysik und Quantenchemie PDF
Author: Hermann Haken
Publisher: Springer-Verlag
Category : Science
Languages : de
Pages : 416
View: 3631

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Book Description:
Dieses Lehrbuch wendet sich an Studenten der Physik, der Physikalischen Chemie und der Theoretischen Chemie. Aufbauend auf Grundkenntnissen der Atom- und Quantenphysik vemitteln die Autoren den Stoff, der zum Grundwissen eines jeden Physikstudenten gehört. Für den Studenten der Chemie bedeuten die in diesem Buch vorgestellten Konzepte das theoretische Grundgerüst für sein Fachgebiet. Dieses Gerüst befähigt ihn, den ungeheuren Erfahrungsschatz der Chemie auf wenige Prinzipien, nämlich die der Quantentheorie, zurückzuführen. Zwei untrennbar miteinander verknüpfte Themenbereiche werden behandelt: die chemische Bindung und die physikalischen Eigenschaften der Moleküle. Erstmals behandelt ein Lehrbuch die Molekülphysik und Quantenchemie in dieser Kombination mit der Zielsetzung, das Grundlegende und Typische herauszuarbeiten, und so dem Studenten einen Überblick über dieses so wichtige und reizvolle Gebiet zu vermitteln. Darüber hinaus vermittelt das Buch Ausblicke auf neue Entwicklungen, etwa die Erforschung der Photosynthese, die Physik supramolekularer Funktionseinheiten und die molekulare Mikroelektronik.


Early Days Of X Ray Crystallography

Early Days of X ray Crystallography PDF
Author: André Authier
Publisher: OUP Oxford
Category : Science
Languages : en
Pages : 464
View: 5138

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Book Description:
The year 2012 marked the centenary of one of the most significant discoveries of the early twentieth century, the discovery of X-ray diffraction (March 1912, by Laue, Friedrich and Knipping) and of Bragg's law (November 1912). The discovery of X-ray diffraction confirmed the wave nature of X-rays and the space-lattice hypothesis. It had two major consequences: the analysis of the structure of atoms, and the determination of the atomic structure of materials. This had a momentous impact in chemistry, physics, mineralogy, material science, biology and X-ray spectroscopy. The book relates the discovery itself, the early days of X-ray crystallography, and the way the news of the discovery spread round the world. It explains how the first crystal structures were determined by William Bragg and his son Lawrence, and recounts which were the early applications of X-ray crystallography in chemistry, mineralogy, materials science, physics, biological sciences and X-ray spectroscopy. It also tells how the concept of space lattice developed since ancient times up to the nineteenth century, and how our conception of the nature of light has changed over time. The contributions of the main actors of the story, prior to the discovery, at the time of the discovery and immediately afterwards, are described through their writings and are put into the context of the time, accompanied by brief biographical details. This thoroughly researched account on the multiple faces of a scientific specialty, X-ray crystallography, is aimed both at the scientists, who rarely subject the historical material of past discoveries in their field to particular scrutiny with regard to the historical details and at the historians of science who often lack the required expert knowledge to scrutinize the involved technical content in sufficient depth (M. Eckert - Metascience).