Spectral- and frequency-encoded fluorescence imaging

A method for obtaining fluorescence images with a high number of resolvable points by using spectral and frequency encoding is presented. Broadband excitation light is encoded with a wavelength-dependent frequency modulation and dispersed onto the sample with a grating to simultaneously illuminate an entire image line. The Fourier transform of the frequency-encoded fluorescence emission provides one line of the image. Mechanical scanning along a direction orthogonal to the wavelength-encoded axis allows creation of the two-dimensional fluorescent image. This method is applicable for developing submillimeter diameter endoscopes. The principles of the technique are validated by imaging indocyanine green fluorescence in microfluidic channels.     

How Common Are True Aminopyridinato Complexes?

An overview over the binding situation in transition metal and lanthanide aminopyridinato complexes is given. True aminopyridinato complexes in which we observe a significant longer N‐amido than N‐pyridine bond length are rare and for instance observed for ruthenium. Additional examples of ruthenium aminopyridinato complexes were synthesized and characterized by X‐ray crystal structure analysis.     

Acceleration and slowing down of nonlinear wave packets in a weakly nonuniform plasma

The processes of acceleration of nonlinear waves in a weakly inhomogenous plasma and slowing down due to nonlinear Landau damping are compared. For initially standing waves the time needed for reaching equilibrium between these oppossing tendencies is estimated.     

Nonlinear Standing Langmuir Waves

The structure of stationary nonlinear standing Langmuir waves is examined in a self-consistent manner. A singularity for the stationary wave function is found which may cause the Langmuir waves to collapse, or expand indefinitely.     

Connection between light cone singularities and the asymptotic behaviour of the moments of the structure functions

On the basis of the Dyson-Jost-Lehmann representation a light-cone type expansion of the matrix elements of the current commutator can be justified. Suitable moments of the structure functions being defined, the connection between the asymptotic behaviour of the moments as Q² → ∞ and the behaviour of the expansion coefficients as x² → 0 is investigated. To solve this problem a restriction of the allowed class of generalized functions is needed. Then a one-to-one correspondence between both limits can be established.     

Influence of interparticle interactions on the kinetics of self-assembly and mechanical strength of nanoparticulate aggregates

Computer simulations based on Discrete Element Method have been performed in order to investigate the influence of interparticle interactions on the kinetics of self-assembly and the mechanical strength of nanoparticle aggregates.Three different systems have been considered.In the first system the interaction between particles has been simulated using the JKR (Johnson,Kendall and Roberts) contact theory,while in the second and third systems the interaction between particles has been simulated using van der Waals and electrostatic forces respectively.In order to compare the mechanical behaviour of the three systems,the magnitude of the maximum attractive force between particles has been kept the same in all cases.However,the relationship between force and separation distance differs from case to case and thus,the range of the interparticle force.The results clearly indicate that as the range of the interparticle force increases,the self-assembly process is faster and the work required to produce the mechanical failure of the assemblies increases by more than one order of magnitude.