989 research outputs found
Protection of Biodiversity of the Sava River Basin Floodplains : The relevance of farming and farmland for maintaining the landscape and biodiversity of the Sava floodplains
Vibrational Schroedinger Cats
The optical Schroedinger cat states are simple realizations of quantum states having nonclassical features. It is shown that vibrational analogues of such states can be realized in an experiment of double pulse excitation of vibrionic transitions. To track the evolution of the vibrational wave packet we derive a non-unitary time evolution operator so that calculations are made in a quasi Heisenberg picture
High glass forming ability correlated with microstructure and hydrogen storage properties of a Mg-Cu-Ag-Y glass
Thermal characterization of an as-cast Mg54Cu28Ag7Y11 bulk metallic glass revealed that this
alloy exhibits excellent glass forming ability. High-resolution X-ray diffraction study and
transmission electron microscopy show that heating and isothermal annealing treatment
results in the nucleation of nanocrystals of several phases. The average size of these
nanocrystals (~15-20 nm) only slightly varies with prolonged annealing, only their volume
fraction increases. High-pressure calorimetry experiments indicate that the as-cast fully
amorphous alloy exhibits the largest enthalpy of hydrogen desorption, compared to partially and fully crystallized states. Since the fully crystallized alloy does not desorb hydrogen, it is
assumed that hydrogen storage capacity correlates only with the crystalline volume fraction of
the partially crystallized Mg54Cu28Ag7Y11 BMG and additional parameters (crystalline phase
selection, crystallite size, average matrix concentration) do not play a significant role
Interpretation of the Total Magnetic Field Anomalies Measured by the CHAMP Satellite Over a Part of Europe and the Pannonian Basin
In this study we interpret the magnetic anomalies at satellite altitude over a part of Europe and the Pannonian Basin. These anomalies are derived from the total magnetic measurements from the CHAMP satellite. The anomalies reduced to an elevation of 324 km. An inversion method is used to interpret the total magnetic anomalies over the Pannonian Basin. A three dimensional triangular model is used in the inversion. Two parameter distributions: Laplacian and Gaussian are investigated. The regularized inversion is numerically calculated with the Simplex and Simulated Annealing methods and the anomalous source is located in the upper crust. A probable source of the magnetization is due to the exsolution of the hematite-ilmenite minerals
Non equilibrium anisotropic excitons in atomically thin ReS
We present a systematic investigation of the electronic properties of bulk
and few layer ReS van der Waals crystals using low temperature optical
spectroscopy. Weak photoluminescence emission is observed from two
non-degenerate band edge excitonic transitions separated by 20 meV. The
comparable emission intensity of both excitonic transitions is incompatible
with a fully thermalized (Boltzmann) distribution of excitons, indicating the
hot nature of the emission. While DFT calculations predict bilayer ReS to
have a direct fundamental band gap, our optical data suggests that the
fundamental gap is indirect in all cases
Carbon nanotubes adhesion and nanomechanical behavior from peeling force spectroscopy
Applications based on Single Walled Carbon Nanotube (SWNT) are good example
of the great need to continuously develop metrology methods in the field of
nanotechnology. Contact and interface properties are key parameters that
determine the efficiency of SWNT functionalized nanomaterials and nanodevices.
In this work we have taken advantage of a good control of the SWNT growth
processes at an atomic force microscope (AFM) tip apex and the use of a low
noise (1E-13 m/rtHz) AFM to investigate the mechanical behavior of a SWNT
touching a surface. By simultaneously recording static and dynamic properties
of SWNT, we show that the contact corresponds to a peeling geometry, and
extract quantities such as adhesion energy per unit length, curvature and
bending rigidity of the nanotube. A complete picture of the local shape of the
SWNT and its mechanical behavior is provided
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