Ueber den Aufschluss der Silikate

Ohne Zusammenfassung     

Ueber einen Apparat zur fractionirten Destillation

Ohne Zusammenfassung     

Ballistic effects and intersubband excitations in multiple quantum well structures

We have studied the transport properties of electrons in asymmetric quantum well structures upon far-infrared optical excitation of carriers from the lowest subband into the continuum. Here the photocurrent consists of a coherent component originating from ballistic transport upon excitation, and of an incoherent part associated with asymmetric diffusion and relaxation processes, which occur after the coherence has been lost. The signature of the coherent contribution is provided by a sign reversal of the photocurrent upon changing the excitation energy. This sign reversal arises from the energy-dependent interference between continuum states, which have a twofold degeneracy characterized by positive and negative momenta. The interference effect also allows us to estimate the coherent mean free path ( nm at 77 K). In specifically designed device structures, we use both the coherent and incoherent components in order to achieve a pronounced photovoltaic infrared response for detector applications.     

Experiments with single atoms in cavities and traps

ＥｘｐｅｒｉｍｅｎｔｓｗｉｔｈｓｉｎｇｌｅａｔｏｍｓｉｎｃａｖｉｔｉｅｓａｎｄｔｒａｐｓＨ．Ｗａｌｔｈｅｒ（ＳｅｋｔｉｏｎＰｈｙｓｉｋｄｅｒＵｎｉｖｅｒｓｉｔａｔＭｕｎｃｈｅｎａｎｄＭａｘ－Ｐｌａｎｃｋ－ＩｎｓｔｉｔｕｔｆｕｒＱｕａｎｔｅｎｏｐｔｉｋ...     

Polyhedral graphs with extreme numbers of types of faces

A face F of a polyhedral graph G(V,E,F) is an a₁,a₂,…,a_l-face if is an l-gon and the degrees d(x_i) of the vertices x_iV incident with in the cyclic order are a_i,i=1,2,…,l. The lexicographic minimum b₁,b₂,…,b_l such that is a b₁,b₂,…,b_l-face is the type of . All polyhedral graphs having only one type of faces are listed. It is proved that the set of triangulations having only faces of different types is non-empty and finite.     

On a Model for Soft Landing with State-Dependent Delay

Automatic soft landing is modeled by a differential equation with state-dependent delay. It is shown that in the model soft landing occurs for an open set of initial data, which is determined by means of a smooth invariant manifold.      

Dendronized Hyperbranched Macromolecules: Soft Matter with a Novel Type of Segmental Distribution

Dendronization of a hyperbranched polyester with different generation dendrons leads to pseudo‐dendritic structures. The hyperbranched core is modified by the divergent coupling of protected monomer units to the functional groups. Compared to dendrimers, the synthetic effort is significantly less, but the properties are very close to those of high‐generation dendrimers. The number of functional groups, molar mass, and rheology behavior even in the early generation (G1–G4) pseudo‐dendrimers strongly resembles the behavior of dendrimers in higher generations (G5–G8). Comparison of the segmental and internal structure with perfect dendrimers is performed using SANS, dynamic light scattering and viscosity analysis, microscopy and molecular dynamics simulation. The interpretation of the results reveals unique structural characteristics arising from lower segmental density of the core, which turns into a soft nano‐sphere with a smooth surface even in the first generation.