3,121 research outputs found
Procedure for pressure contact on high-power semiconductor devices free of thermal fatigue
To eliminate thermal fatigue, a procedure for manufacturing semiconductor power devices with pure pressure contact without solid binding was developed. Pressure contact without the use of a solid binding to avoid a limitation of the maximum surface in the contact was examined. A silicon wafer covered with a relatively thick metal layer is imbedded with the aid of a soft silver foil between two identically sized hard contact discs (molybdenum or tungsten) which are rotationally symmetrical. The advantages of this concept are shown for large diameters. The pressure contact was tested successfully in many devices in a large variety of applications
Swift-Hohenberg equation with broken reflection symmetry
The bistable Swift-Hohenberg equation possesses a variety of time-independent spatially localized solutions organized in the so-called snakes-and-ladders structure. This structure is a consequence of a phenomenon known as homoclinic snaking, and is in turn a consequence of spatial reversibility of the equation. We examine here the consequences of breaking spatial reversibility on the snakes-and-ladders structure. We find that the localized states now drift, and show that the snakes-and-ladders
structure breaks up into a stack of isolas. We explore the evolution of this new structure with increasing reversibility breaking and study the dynamics of the system outside of the snaking region using a combination of numerical and analytical techniques
Interpersonal Behavior in Couple Therapy: Concurrent and Prospective Associations with Depressive Symptoms and Relationship Distress
Objective: This study investigated associations between couples’ interpersonal behavior, depressive symptoms, and relationship distress over the course of couple psychotherapy. Method: After every other session of Integrative Systemic Therapy (M = 13 sessions), N = 100 individuals within 50 couples rated their in-session affiliation and autonomy behavior using the circumplex-based Structural Analysis of Social Behavior Intrex. Concurrent and prospective associations of interpersonal behavior with depressive symptoms and relationship distress were evaluated via multivariate multilevel modeling using the Actor-Partner Interdependence Model. Results: An individual’s hostility, as well as the partner’s hostility, positively predicted an individual’s concurrent depressive symptoms and relationship distress, as well as his or her relationship distress at the following session. Partner hostility during one session predicted an individual’s subsequent depressive symptoms. During sessions in which individuals controlled the partner, and separated themselves from the partner, they reported more concurrent depressive symptoms and relationship distress, and more subsequent relationship distress. When partners separated themselves, individuals reported more concurrent depressive symptoms and relationship distress, and more subsequent relationship distress. Conclusions: Results underscore the importance of couples’ in-session affiliation and autonomy behavior in the treatment of depressive symptoms and relationship distress within couple therapy
Matauitatau - ein sehr kontroverses Problem der philologischen Textkritik der Stelle bei Petronius, Cena Trimalchionis 62,9
Solidification in soft-core fluids: disordered solids from fast solidification fronts
Using dynamical density functional theory we calculate the speed of
solidification fronts advancing into a quenched two-dimensional model fluid of
soft-core particles. We find that solidification fronts can advance via two
different mechanisms, depending on the depth of the quench. For shallow
quenches, the front propagation is via a nonlinear mechanism. For deep
quenches, front propagation is governed by a linear mechanism and in this
regime we are able to determine the front speed via a marginal stability
analysis. We find that the density modulations generated behind the advancing
front have a characteristic scale that differs from the wavelength of the
density modulation in thermodynamic equilibrium, i.e., the spacing between the
crystal planes in an equilibrium crystal. This leads to the subsequent
development of disorder in the solids that are formed. For the one-component
fluid, the particles are able to rearrange to form a well-ordered crystal, with
few defects. However, solidification fronts in a binary mixture exhibiting
crystalline phases with square and hexagonal ordering generate solids that are
unable to rearrange after the passage of the solidification front and a
significant amount of disorder remains in the system.Comment: 18 pages, 14 fig
Localized states in the conserved Swift-Hohenberg equation with cubic nonlinearity
The conserved Swift-Hohenberg equation with cubic nonlinearity provides the
simplest microscopic description of the thermodynamic transition from a fluid
state to a crystalline state. The resulting phase field crystal model describes
a variety of spatially localized structures, in addition to different spatially
extended periodic structures. The location of these structures in the
temperature versus mean order parameter plane is determined using a combination
of numerical continuation in one dimension and direct numerical simulation in
two and three dimensions. Localized states are found in the region of
thermodynamic coexistence between the homogeneous and structured phases, and
may lie outside of the binodal for these states. The results are related to the
phenomenon of slanted snaking but take the form of standard homoclinic snaking
when the mean order parameter is plotted as a function of the chemical
potential, and are expected to carry over to related models with a conserved
order parameter.Comment: 40 pages, 13 figure
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