5,751 research outputs found
4,4′-(Propane-1,3-diyl)dipyridinium tetrachloridonickelate(II)
The title compound, (C13H16N2)[NiCl4] or (H2bpp)·NiCl4 [bpp is 1,3-bis(4-pyridyl)propane], is isostructural with its already reported Cu, Zn and Hg analogues. The structure consists of a doubly charged (H2bpp)2+ cation and a tetrahedral [NiCl4]2− dianion. Both pyridyl N atoms are protonated and form a (H2bpp)2+ cation which adopts an anti–anti conformation with a dihedral angle of 6.287 (7)° between the pyridyl rings. The two pyridyl N atoms are both involved in strong N—H⋯Cl hydrogen bonds, which link both units into a dimer
Quantum games of asymmetric information
We investigate quantum games in which the information is asymmetrically
distributed among the players, and find the possibility of the quantum game
outperforming its classical counterpart depends strongly on not only the
entanglement, but also the informational asymmetry. What is more interesting,
when the information distribution is asymmetric, the contradictive impact of
the quantum entanglement on the profits is observed, which is not reported in
quantum games of symmetric information.Comment: 5 pages, 3 figure
Quantum Discord for Investigating Quantum Correlations without Entanglement in Solids
Quantum systems unfold diversified correlations which have no classical
counterparts. These quantum correlations have various different facets. Quantum
entanglement, as the most well known measure of quantum correlations, plays
essential roles in quantum information processing. However, it has recently
been pointed out that quantum entanglement cannot describe all the
nonclassicality in the correlations. Thus the study of quantum correlations in
separable states attracts widely attentions. Herein, we experimentally
investigate the quantum correlations of separable thermal states in terms of
quantum discord. The sudden change of quantum discord is observed, which
captures ambiguously the critical point associated with the behavior of
Hamiltonian. Our results display the potential applications of quantum
correlations in studying the fundamental properties of quantum system, such as
quantum criticality of non-zero temperature.Comment: 4 pages, 4 figure
Vision based navigation system for autonomous proximity operations: an experimental and analytical study
This dissertation presents an experimental and analytical study of the Vision Based Navigation system (VisNav). VisNav is a novel intelligent optical sensor system invented by Texas A&M University recently for autonomous proximity operations. This dissertation is focused on system calibration techniques and navigation algorithms. This dissertation is composed of four parts. First, the fundamental hardware and software design configuration of the VisNav system is introduced. Second, system calibration techniques are discussed that should enable an accurate VisNav system application, as well as characterization of errors. Third, a new six degree-of-freedom navigation algorithm based on the Gaussian Least Squares Differential Correction is presented that provides a geometrical best position and attitude estimates through batch iterations. Finally, a dynamic state estimation algorithm utilizing the Extended Kalman Filter (EKF) is developed that recursively estimates position, attitude, linear velocities, and angular rates. Moreover, an approach for integration of VisNav measurements with those made by an Inertial Measuring Unit (IMU) is derived. This novel VisNav/IMU integration technique is shown to significantly improve the navigation accuracy and guarantee the robustness of the navigation system in the event of occasional dropout of VisNav data
- …