713 research outputs found
Electrical transport and low-temperature scanning tunneling microscopy of microsoldered graphene
Using the recently developed technique of microsoldering, we perform a
systematic transport study of the influence of PMMA on graphene flakes
revealing a doping effect of up to 3.8x10^12 1/cm^2, but a negligible influence
on mobility and gate voltage induced hysteresis. Moreover, we show that the
microsoldered graphene is free of contamination and exhibits a very similar
intrinsic rippling as has been found for lithographically contacted flakes.
Finally, we demonstrate a current induced closing of the previously found
phonon gap appearing in scanning tunneling spectroscopy experiments, strongly
non-linear features at higher bias probably caused by vibrations of the flake
and a B-field induced double peak attributed to the 0.Landau level of graphene.Comment: 8 pages, 3 figure
Orientation to light of juvenile and adult forms of melanic and albino populations of Biomphalaria glabrata (Say, 1818)
The new ASDEX upgrade upper divertor for special alternative configurations: Design and FEM calculations
Room temperature synthesis and characterization of novel lead-free double perovskite nanocrystals with a stable and broadband emission
Low-dimensional and lead-free halide perovskites are of great interest for their wide application potential for optoelectronic applications. We report on the successful synthesis of novel lead-free colloidal Cs3BiBr6 nanocrystals (NCs) with an ultra-small size of ~1.5-3 nm by a room temperature antisolvent process. From crystallographic characterization we show that it is critical to precisely control the ratio of precursors to obtain the pure 3-1-6 phase. The synthesis process is facile and repeatable and results in Cs3BiBr6 NCs that display stable blue emission around 438 nm with a relatively broad linewidth of 92.1 nm. Low-temperature photoluminescence (PL) measurements displayed a red-shift of bandgap with decreasing temperature, which might be attributed to the thermal expansion of the lattice. In addition, the NCs demonstrate high stability at ambient conditions. This journal i
Study of a population of Biomphalaria tenagophila (Orbigny, 1835) and of schistosomiasis transmission in "Alto da Boa Vista", Rio de Janeiro
Universal Slip Dynamics in Metallic Glasses and Granular Matter – Linking Frictional Weakening with Inertial Effects
Slowly strained solids deform via intermittent slips that exhibit a material-independent critical size distribution. Here, by comparing two disparate systems - granular materials and bulk metallic glasses - we show evidence that not only the statistics of slips but also their dynamics are remarkably similar, i.e. independent of the microscopic details of the material. By resolving and comparing the full time evolution of avalanches in bulk metallic glasses and granular materials, we uncover a regime of universal deformation dynamics. We experimentally verify the predicted universal scaling functions for the dynamics of individual avalanches in both systems, and show that both the slip statistics and dynamics are independent of the scale and details of the material structure and interactions, thus settling a long-standing debate as to whether or not the claim of universality includes only the slip statistics or also the slip dynamics. The results imply that the frictional weakening in granular materials and the interplay of damping, weakening and inertial effects in bulk metallic glasses have strikingly similar effects on the slip dynamics. These results are important for transferring experimental results across scales and material structures in a single theory of deformation dynamics
- …