springer vieweg jan 1992 (5 risultati)

Taschenbuch. Condizione: Neu. This item is printed on demand - it takes 3-4 days longer - Neuware -In this expository paper we sketch some interrelations between several famous conjectures in number theory and algebraic geometry that have intrigued mathematicians for a long period of time. Starting from Fermat's Last Theorem one is naturally led to intro duce L-functions, the main motivation being the calculation of class numbers. In particular, Kummer showed that the class numbers of cyclotomic fields playa decisive role in the corroboration of Fermat's Last Theorem for a large class of exponents. Before Kummer, Dirich let had already successfully applied his L-functions to the proof of the theorem on arithmetic progressions. Another prominent appearance of an L-function is Riemann's paper where the now famous Riemann Hypothesis was stated. In short, nineteenth century number theory showed that much, if not all, of number theory is reflected by proper ties of L-functions. Twentieth century number theory, class field theory and algebraic geometry only strengthen the nineteenth century number theorists's view. We just mention the work of E. Heeke, E. Artin, A. Weil and A. Grothendieck with his collaborators. Heeke generalized Dirichlet's L-functions to obtain results on the distribution of primes in number fields. Artin introduced his L-functions as a non-abelian generaliza tion of Dirichlet's L-functions with a generalization of class field the ory to non-abelian Galois extensions of number fields in mind. Weil introduced his zeta-function for varieties over finite fields in relation to a problem in number theory. 240 pp. Deutsch.

Taschenbuch. Condizione: Neu. This item is printed on demand - it takes 3-4 days longer - Neuware -The investment good market, together with the consumer good market, the money market and the labour market, are indeed the most extensively studied markets. The exhaustive survey of investment theory by Eisner and Strotz, already quoted four hundred references in 1963, although this work advocating for adjustment costs, was in fact only carried out at the very beginning of modern investment theory! This chapter gives an introduction of the extensive field and is an attempt to present some key ideas of investment theory. 1) We show that modern investment theory is the integration of many traditional approaches. The content of the chapter is set as follows. Section 2 presents an illustrative model of investment theory. Section 3, using this model, describes the investment decision of the firm. Sections 4 to 10 each present a 'classical' investment hypothesis within the framework of the model. Section 11 concludes. For convenience, the key to the symbols used is given in Table 1. 2. The Model of the Firm Investment theory was born with the claim of Keynes (1936) that besides the capital demand (demand for a stock of capital at a point in time), an investment demand (demand for the increment of the capital stock in a period 1) Recent surveys are: Abel (1988), Coen and Eisner (1987) Artus and Muet (1984). The book on investment theory by Nickell (1978) is outstanding. 236 pp. Englisch.

Taschenbuch. Condizione: Neu. This item is printed on demand - it takes 3-4 days longer - Neuware -The presence of freely moving charges gives peculiar properties to electrolyte solutions, such as electric conductance, charge transfer, and junction potentials in electrochemical systems. These charges play a dominant role in transport processes, by contrast with classical equilibrium thermodynamics which considers the electrically neutral electrolyte compounds. The present status of transport theory does not permit a first prin ciples analys1s of all transport phenomena with a detailed model of the relevant interactions. Host of the models are still unsufficient for real systems of reasonable complexity. The Liouville equation may be adapted with some Brownian approximations to problems of interact ing solute particles in a continuum (solvent; however, keeping the Liouville level beyond the limiting laws is an unsolvable task. Some progress was made at the Pokker-Planck level; however, despite a promising start, this theory in its actual form is still unsatis factory for complex systems involving many ions and chemical reac tions. A better approach is provided by the so-called Smoluchowski level in which average velocities are used, but there the hydrodyna mic interactions produce some difficulties. The chemist or chemical engineer, or anyone working with complex electrolyte solutions in applied research wants a general representa tion of the transport phenomena which does not reduce the natural complexity of the multicomponent systems. Reduction of the natural complexity generally is connected with substantial changes of the systems. 228 pp. Englisch.

Taschenbuch. Condizione: Neu. This item is printed on demand - it takes 3-4 days longer - Neuware -. . . :no ___ :_:_ und nimmt ab auf an einem Ende und ~ derselben Seite. 320 pp. Deutsch.

Taschenbuch. Condizione: Neu. This item is printed on demand - it takes 3-4 days longer - Neuware -Das SchweiBen zahlt systematisch zu den Fiigetechniken. In DIN 8953 sind die Ver fahren des Fiigens in sechs Gruppen geordnet, Bild 1.1. Die Gruppe 4.6, Stoffverbin den, unterscheidet nach drei Untergruppen in . SchweiBen, L6ten und Kleben, Leimen, Kitten. Alle dort genannten Verfahren zahlen zu den unl6sbaren, stoffschliissigen Verbindun gen. Die Abgrenzung der unl6sbaren Verbindungen zueinander erfolgt fiir die drei wich tigsten Verfahren zweckmaBig iiber deren Definition wie folgt: SchweiBen ist das unl6sbare Vereinigen von Grundwerkstoffen (Verbindungsschwei Ben) oder das Beschichten eines Grundwerkstoffes (AuftragschweiBen) unter Anwendung von Warme oder von Druck oder von beidem, mit oder ohne Zusatzwerkstoffe. L6ten ist das Verbinden metallischer Werkstiicke mit Hilfe eines geschmolzenen Zusatzmetalls (Lots), dessen Schmelztemperatur unterhalb derjenigen der zu verbindenden Grundwerkstoffe liegt. Die Grundwerkstoffe werden nicht aufgeschmolzen, sondern nur be netzt. Gegebenenfalls wird mit FluBmitteln gearbeitet. Kleben ist das Fiigen zweier Teile unter Verwendung eines Klebstoffs, d.h. eines nichtmetallischen Werkstoffs, der die Fiigeteile durch Oberflachenhaftung (Adhasion) sowie zwischen- und innermolekulare Kr1ifte im Kleber (Kohasion) miteinander verbindet. Das wichtigste Verfahren davon ist derzeit das SchweiBen. Je nach Art des zu verbin denden Grundwerkstoffes, dem Zweck des SchweiBens oder der Art der Fertigung k6nnen weitere systematische Unterteilungen vorgenommen werden. 233 pp. Deutsch.