878 research outputs found
Gust-tunnel Investigation of the Effect of Leading Edge Separation on the Normal Accelerations Experienced by a 45 Degree Sweptback-wing Model in Gusts
A formula for the First Eigenvalue of the Dirac Operator on Compact Spin Symmetric Spaces
Let be a simply connected spin compact inner irreducible symmetric
space, endowed with the metric induced by the Killing form of sign-changed.
We give a formula for the square of the first eigenvalue of the Dirac operator
in terms of a root system of . As an example of application, we give the
list of the first eigenvalues for the spin compact irreducible symmetric spaces
endowed with a quaternion-K\"{a}hler structure
Toeplitz operators on symplectic manifolds
We study the Berezin-Toeplitz quantization on symplectic manifolds making use
of the full off-diagonal asymptotic expansion of the Bergman kernel. We give
also a characterization of Toeplitz operators in terms of their asymptotic
expansion. The semi-classical limit properties of the Berezin-Toeplitz
quantization for non-compact manifolds and orbifolds are also established.Comment: 40 page
Low temperature, postgrowth self-doping of CdTe single crystals due to controlled deviation from stoichiometry
Careful analysis of the Cd-Te pressure-temperature-composition phase diagram, shows a deviation of CdTe stoichiometry only in the Te-depletion direction between 450 and 550 degrees C. Combined control over the semiconductor composition, via intrinsic defects, and over the atmosphere and cooling rate can, therefore, yield a process for intrinsic doping of CdTe at these relatively low temperatures. We present results that support this. Quenching of CdTe, following its annealing in Te atmosphere at 400-550 degrees C, leads to p-type conductivity with a hole concentration of similar to 2 x 10(16) cm(-3). Slow cooling of the samples, after 550 degrees C annealing in Te or in vacuum, increases the hole concentration by one order of magnitude, as compared to quenching at the same temperature. We explain this increase by the defect reaction between Te vacancies and Te interstitials. Annealing in Cd at 400-550 degrees C leads to n-type conductivity with an electron concentration of similar to 2 x 10(16) cm(-3). Annealing at 450-550 degrees C in the equilibrium atmosphere, provided by adding CdTe powder, gives n-type material
Hard carbons as anode for sodium-ion batteries: influence of material properties on electrochemical performances
A correlation of results of flight investigation with results of an analytical study of effects of wing flexibility on wing strains due to gusts
An analytical study of the effects of wing flexibility on wing strains due to gusts has been made for four spanwise stations of a four-engine bomber airplane, and the results have been correlated with results of a previous flight investigation
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