17,503 research outputs found
Recommended from our members
Rich Chemistry in Inorganic Halide Perovskite Nanostructures.
Halide perovskites have emerged as a class of promising semiconductor materials owing to their remarkable optoelectronic properties exhibiting in solar cells, light-emitting diodes, semiconductor lasers, etc. Inorganic halide perovskites are attracting increasing attention because of the higher stability toward moisture, light, and heat as compared with their organic-inorganic hybrid counterparts. In particular, inorganic halide perovskite nanomaterials provide controllable morphology, tunable optoelectronic properties, and improved quantum efficiency. Here, the development controlled synthesis of desired inorganic halide perovskite nanostructures by various chemical approaches is described. Utilizing these nanostructures as platforms, anion exchange chemistry for wide compositional and optical tunabilities is described, and the rich structural phase transition phenomenon and mechanism investigated systematically. Furthermore, these nanostructures and extracted knowledge are applied to design photonic, photovoltaic, and thermoelectric devices. Finally, future directions and challenges toward improvement of the optical, electrical, and optoelectronic properties, exploration of the anion and cation exchange kinetics, and alleviation of the stability and toxicity issues in inorganic lead based halide perovskites are discussed to provide an outlook on this promising field
Spin-dependent Rotating Wigner Molecules in Quantum dots
The spin-dependent trial wave functions with rotational symmetry are
introduced to describe rotating Wigner molecular states with spin degree of
freedom in four- and five-electron quantum dots under magnetic fields. The
functions are constructed with unrestricted Hartree-Fock orbits and projection
technique in long-range interaction limit. They highly overlap with the
exact-diagonalized ones and give the accurate energies in strong fields. The
zero points, i.e. vortices of the functions have straightforward relations to
the angular momenta of the states. The functions with different total spins
automatically satisfy the angular momentum transition rules with the increase
of magnetic fields and explicitly show magnetic couplings and characteristic
oscillations with respect to the angular momenta. Based on the functions, it is
demonstrated that the entanglement entropies of electrons depend on the
z-component of total spin and rise with the increase of angular momenta
Sandtime: A Tangible Interaction Featured Sensory Play Installation For Children To Increase Social Connection
From the study of social-interaction enhanced gaming design, aimed at providing a public environment which supports tangible & social interactions among children, we designed Sandtime. Sandtime is a public installation designed to encourage such interaction. Using the Tangible Interaction Design approach, this gaming installation features collaborative play and social interactions under public context, where children can collaboratively interact with the virtual onscreen characters by manipulating physical objects. This design is based on the study of how interactive gaming facilities can help to ease anxiety and enhance social interactions among children. In this paper, we want to continue this line of research by exploring further the elements that can enhance such interaction experience. This paper focuses specifically on the sensory play and how it can help to facilitate social interaction
Aharonov-Bohm phase operations on a double-barrier nanoring charge qubit
We present a scheme for charge qubit implementation in a double-barrier
nanoring. The logical states of the qubit are encoded in the spatial
wavefunctions of the two lowest energy states of the system. The Aharonov-Bohm
phase introduced by magnetic flux, instead of tunable tunnelings, along with
electric fields can be used for implementing the quantum gate operations.
During the operations, the external fields should be switched smoothly enough
to avoid the errors caused by the transition to higher-lying states. The
structure and field effects on the validity of the qubit are also studied.Comment: 6 pages, 7 figure
A novel fault-tolerant control strategy for near space hypersonic vehicles via least squares support vector machine and backstepping method
Near Space Hypersonic Vehicle (NSHV) could play significant roles in both military and civilian applications. It may cause huge losses of both personnel and property when a fatal fault occurs. It is therefore paramount to conduct fault-tolerant research for NSHV and avoid some catastrophic events. Toward this end, this paper presents a novel fault-tolerant control strategy by using the LSSVM (Least Squares Support Vector Machine)-based inverse system and Backstepping method. The control system takes advantage of the superiority of the LSSVM in solving the problems with small samples, high dimensions and local minima. The inverse system is built with an improved LSSVM. The adaptive controller is designed via the Backstepping which has the unique capability in dealing with nonlinear control systems. Finally, the experiment results demonstrate that the proposed method performs well
- …