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We present a semiclassical perturbation method for the description of atomic diffraction by a weakly modulated potential. It proceeds in a way similar to the treatment of light diffraction by a thin phase grating, and consists in calculating the atomic wavefunction by means of action integrals along the classical trajectories of the atoms in the absence of the modulated part of the potential. The capabilities and the validity condition of the method are illustrated on the well-known case of atomic diffraction by a Gaussian standing wave. We prove that in this situation the perturbation method is equivalent to the Raman-Nath approximation, and we point out that the usually-considered Raman-Nath validity condition can lead to inaccuracies in the evaluation of the phases of the diffraction amplitudes. The method is also applied to the case of an evanescent wave reflection grating, and an analytical expression for the diffraction pattern at any incidence angle is obtained for the first time. Finally, the application of the method to other situations is briefly discussed.
Nasledujúci príspevok poslal časopisu Viera a život vedecký pracovník katolíckej teologickej fakulty na Regensburskej univerzite (Nemecko) pán Stefan Gatzhammer, M. A., Líc. iur. can. Podkladom pre článok bola rozpracovaná vedecká štúdia, preto aj nemecká pôvodina príspevku mala bohaté a dôkladné poznámky. S láskavým súhlasom autora sme pre potreby našich čitateľov poznámky zjednodušili. Pôvodný nemecký titul článku znie: „Die Ausweisung der Jesuiten aus Portugal 1759/60. Der Brasilienmissionar P. Josef Keyling SJ aus Schemnitz." Príspevok do slovenčiny preložila Zuzana Vaňová.
We have studied bifurcation phenomena for the incompressable Navier-Stokes equations in two space dimensions with periodic boundary conditions. Fourier representations of velocity and pressure have been used to transform the original partial differential equations into systems of ordinary differential equations (ODE), to which then numerical methods for the qualitative analysis of systems of ODE have been applied, supplemented by the simulative calculation of solutions for selected initial conditions. Invariant sets, notably steady states, have been traced for varying Reynolds number or strength of the imposed forcing, respectively. A complete bifurcation sequence leading to chaos is described in detail, including the calculation of the Lyapunov exponents that characterize the resulting chaotic branch in the bifurcation diagram.
Underlying the importance of revenue the author discusses the future of the international order from the perspective of political economy. The international system will not be a capitalist one. Political conflicts will not be removed by nonviolent market regulations. Weakness of labour force and a dominant role of revenue will further more result in political interventions by nation states. The struggle for revenue to maintain comparative advantages in high-tech-development strengthens state intervention in order to protect domestic market. The failure of the "development state" in the third world and the rising of fundamentalistic tendencies supported by a market-oriented middle class will increase conflicts in those regions.
Earlier investigations at South Creek in northeastern Queensland established the importance of overland flow as a hydrologic pathway in this tropical rainforest environment. Since this pathway is ‘fast’, transmitting presumably ‘new’ water, its importance should be reflected in the stormflow chemistry of South Creek: the greater the volumentric contribution to the stormflow hydrograph, the more similarity between the chemical composition of streamwater and of overland flow is to be expected. Water samples were taken during two storm events in an ephemeral gully (gully A), an intermittent gully (gully B) and at the South Creek catchment outlet; additional spot checks were made in several poorly defined rills. The chemical composition of ‘old’ water was determined from 45 baseflow samples collected throughout February. The two events differed considerably in their magnitudes, intensities and antecedent moisture conditions. In both events, the stormflow chemistry in South Creek was characterized by a sharp decrease in Ca, Mg, Na, Si, Cl, EC, ANC, alkalinity and total inorganic carbon. pH remained nearly constant with discharge, whereas K increased sharply, as did sulfate in an ill-defined manner. In event 1, this South Creek stormflow pattern was closely matched by the pattern in gully A, implying a dominant contribution of ‘new’ water. This match was confirmed by the spot samples from rills. Gully B behaved like South Creek itself, but with a dampened ‘new’ water signal, indicating less overland flow generation in its subcatchment. In event 2, which occurred five days later, the initial ‘new’ water signal in gully A was rapidly overwhelmed by a different signal which is attributed to rapid drainage from a perched water table. This study shows that stormflow in this rainforest catchment consists predominantly of ‘new’ water which reaches the stream channel via ‘fast’ pathways. Where the ephemeral gullies delivering overland flow are incised deeply enough to intersect a perched water table, a delayed, ‘old’ water-like signal may be transmitted.
Throughfall measurements were made under primary terra firme rainforest in the Rio Pichis valley, in the Upper Amazon Basin of Peru. Based on 214 precipitation events over nearly 18 months, throughfall was estimated to be 83.1±8.8% of gross precipitation. Regression analysis of all events revealed that gross precipitation is the only significant explanatory variable; the use of one-burst events does not significantly improve the regression relationship. Gross precipitation is, however, a poor predictor of throughfall for small rainfall events. The two forest structure parameters, canopy capacity, S, and free throughfall coefficient, p, were determined to be 1.3±0.2 mm and 0.32±0.18 mm. Rainfall intensity was found to influence these parameters. New methods which attempt to minimize the influence of meteorologic variables are used to estimate the potential values of these canopy parameters.
Although without providing a systematical comparison, it has become clear that the sects or party-factions of Japan’s New Left movement are by no means merely copies of their counterparts in the West. On the other hand their conduct may not be judged as to be a unique Japanese phenomenon. What they embody is, on the whole, a complex symbiosis of universal and particularly Japanese features, which can be observed in the fields of social behavior, organizational structure, and group dynamics. The particularity of the New Left factions is mostly revealed through the higher intensity of specific features rather than through pecularities found only in Japan.
This study investigated the relation between interest in four different subject areas (mathematics, biology, English, history) and the quality of experience in class. The strength of interest as a predictor of experience was contrasted with that of achievement motivation and scholastic ability. A total of208 highly able freshmen and sophomores completed interest ratings, an achievement motivation questionnaire, and the Preliminary Scholastic Aptitude Test (PSAT). These assessments were followed by one week of experience sampling. In addition, grades were available for the subject areas involved. The results showed that interest was a significant predictor of the experience of potency, intrinsic motivation, self-esteem, and perception of skill. Controlling for ability and achievement motivation did not decrease the strength of these relations. Achievement motivation and ability proved to be considerably weaker predictors of the quality of experience than was interest. In addition, interest contributed significantly to the prediction of grades in mathematics, biology, and history, but not English. The main results and some limitations of the study are discussed, and suggestions for future research are made.
There has never been a theory of transition from really existing Socialism to a democratic and market-oriented system. Different theoretical approaches are taken into consideration by the author. Experiences of other transitional processes are practicable on Eastern Europe in a limited way. The missing of socio-structural differentiation, the socio-cultural consequences of the really existing Socialism and the international conditions did not promote the transition. It seems that the transition in Eastern Europe is obviously not a change from one political system to another one, but for the time being an open process.
Inhalt: 1. Vorbemerkungen 2. Zu einigen philosophischen und theoretisch-linguistischen Grundlagen einer kommunikativ orientierten Betrachtung der Sprache 3. Sprache und menschliche Gesellschaft 4. Der Euphemismus 5. Euphemismen im Golfkrieg - Zur Analyse der Untersuchungsergebnisse 6. Zusammenfassung und Schlußfolgerungen 7. Perspektiven der kommunikativen Sprachforschung bezüglich 215der Untersuchung des politischen Euphemismus - Forschungsausblick und Schlußbemerkungen
Inhalt: Umweltbeziehungen und Verantwortungsbewußtsein von Unternehmen -Ökologische Anliegen der Unternehmensumwelt -Verantwortliches Verhalten von Unternehmen -Der Risiko- und Krisenbegriff Subjektive Wahrnehmung und Bewertung von Risiken und Krisen -Subjektive Risikowahrnehmung: Wahrnehmung quantitativer Risikofaktoren,die Wahrnehmung qualitativer Merkmale der Risikoquelle, individuelle Risikodeterminanten -Empirische Studie zur Risikowahrnehmung -Subjektive Krisenbewältigung: Prozesse der Krisenentstehung und –entwicklung, Merkmale der Krisenwahrnehmung durch Manager, Verhaltenswissenschaftliche Theorien zur Krisenbewältigung Risiko- und Krisenmanagement
Inhalt: 1. Kritische Erläuterung der Bilder und Texte jeder Folge - 1. Folge: Funde der Bronzezeit (Ein Film von Uschi Demitter) - 2. Folge: Germanische Stämme (Ein Film von Uschi Demitter) - 3. Folge: Siedlung der Slawen (Ein Film von Kurt Barthel - 4. Folge: Das verschwundene Heiligtum (Ein Film von Kurt Barthel) - 5. Folge: Von der Kaiserpfalz zur Stadt (Ein Film von Uschi Demitter und Richard Krause) 2. Einordnung der historischen Details der Folgen in den Geschichtsprozeß - 1. Folge: Funde der Bronzezeit - 2. Folge: Germanische Stämme - 3. Folge: Siedlung der Slawen - 4. Folge: Das verschwundene Heiligtum - 5. Folge: Von der Kaiserpfalz zur Stadt 3. Didaktisch-methodische Empfehlungen zum Einsatz der Sendereihe 3.1 Zuordnung der Sendefolgen zu den Rahmenplänen 3.2 Hinweise für die Unterrichtsarbeit des Lehrers 4. Ergänzende Medien zu den Themenbereichen in der Sammlung des MPZ
Many methods have been proposed for the stabilization of higher index differential-algebraic equations (DAEs). Such methods often involve constraint differentiation and problem stabilization, thus obtaining a stabilized index reduction. A popular method is Baumgarte stabilization, but the choice of parameters to make it robust is unclear in practice. Here we explain why the Baumgarte method may run into trouble. We then show how to improve it. We further develop a unifying theory for stabilization methods which includes many of the various techniques proposed in the literature. Our approach is to (i) consider stabilization of ODEs with invariants, (ii) discretize the stabilizing term in a simple way, generally different from the ODE discretization, and (iii) use orthogonal projections whenever possible. The best methods thus obtained are related to methods of coordinate projection. We discuss them and make concrete algorithmic suggestions.
Many methods have been proposed for the simulation of constrained mechanical systems. The most obvious of these have mild instabilities and drift problems. Consequently, stabilization techniques have been proposed A popular stabilization method is Baumgarte's technique, but the choice of parameters to make it robust has been unclear in practice. Some of the simulation methods that have been proposed and used in computations are reviewed here, from a stability point of view. This involves concepts of differential-algebraic equation (DAE) and ordinary differential equation (ODE) invariants. An explanation of the difficulties that may be encountered using Baumgarte's method is given, and a discussion of why a further quest for better parameter values for this method will always remain frustrating is presented. It is then shown how Baumgarte's method can be improved. An efficient stabilization technique is proposed, which may employ explicit ODE solvers in case of nonstiff or highly oscillatory problems and which relates to coordinate projection methods. Examples of a two-link planar robotic arm and a squeezing mechanism illustrate the effectiveness of this new stabilization method.
Solubilization by polysoaps
(1994)
The aqueous solubilization power of several series of micellar homopolymers and copolymers (polysoaps) is investigated. Using five insoluble or poorly water-soluble dyes, comparisons of the capacities are made with respect ot the influence of structural variables such as the polymer backbone, the polymer geometry, the comonomer content, and the charge of the hydrophilic group. Some guidelines for polysoap structures suited for efficient solubilization are established. Noteworthy is that the solubilization capacities of the polysoaps are neither linked to the ability to reduce the surface tension of water, nor to the polarity of the solubilization sites deduced from spectroscopic probes.
Cognitive acceleration
(1994)
Dieser erste Lehr- und Forschungsbericht des Lehrstuhls für Betriebswirtschaftslehre mit dem Schwerpunkt Marketing beschreibt, analysiert und interpretiert ausgewählte Ergebnisse einer empirischen Studie zum lmage Potsdams bei lokalen Unternehmern. Inhalt: Die Studie im Überblick: Erhebungssteckbrief, Zusammenfassung der wichtigsten Ergebnisse Ziel der Studie Erhebungsdesign und Struktur der Stichprobe Das Image Potsdams als Wirtschaftsstandort - Die Standortfaktoren - Die Einschätzung der Standortfaktoren: Das Überzeugungsprofil - Die Wichtigkeit der Standortfaktoren: Das Anforderungsprofil - Die Stärken und Schwächen Potsdams als Wirtschaftsstandort Typologisierung der lokalen Unternehmer nach ihrem lmage vom Wirtschaftsstandort Potsdam Das lmage Potsdams als Lebensraum für Unternehmer - Das lmageprofil der Stadt Potsdam als Lebensraum - Das 'Innere Bild' von der Stadt Potsdam Die wirtschaftliche Zukunft von Potsdam aus der Sicht der befragten Unternehmer Konsequenzen und Ansatzpunkte für die Gestaltung eines effizienten Regionalen Marketingkonzepts