Evaluating First-Order Molecular Properties of Delocalized Ionic or Excited States in Molecular Aggregates by Renormalized Excitonic Method

In the past few years,the renormalized excitonic model(REM)approach was developed as an efficient low-scaling ab initio excited state method,which assumes the low-lying excited states of the whole system are a linear combination of various single monomer excitations and utilizes the effective Hamiltonian theory to derive their couplings.In this work,we further extend the REM calculations for the evaluations of first-order molecular properties(e.g.charge population and transition dipole moment)of delocalized ionic or excited states in molecular aggregates,through generalizing the effective Hamiltonian theory to effective operator representation.Results from the test calculations for four different kinds of one dimensional(1D)molecular aggregates(ammonia,formaldehyde,ethylene and pyrrole)indicate that our new scheme can efficiently describe not only the energies but also wavefunction properties of the low-lying delocalized electronic states in large systems.

Smart all-time vision:The battery-free video communication for urban administration and law enforcement

The Chinese government is dedicated to enhancing the level of informatization in administrative law enforcement to ensure fairness and increase credibility.Currently,law enforcement has exposed such problems as insufficient force,difficulties in collecting evidence,and low evidential power.These problems contradict the principles of rule of law and standardization.Many local governments have implemented advanced information technologies for urban administration and law enforcement,including big data,artificial intelligence,and IoT.Among these technologies,IoT is the core communication infrastructure for innovative law enforcement platforms.However,traditional video communications rely on batteries or dedicated power sources,leading to maintenance challenges and high power consumption.In this paper,we propose AT-Eye,a new video communication paradigm for all-time law enforcement video monitoring,which is battery-free and high-throughput.The key enabler of AT-Eye is ambient backscatter technology,which enables energy harvesting and video communication simultaneously.Unlike previous methods,our proposal introduces a novel CCK-based modulation for tag cameras and achieves 4-way concurrency.The modulation is simple because it uses phase difference and it is energyefficient because generating square waves is adequate.Moreover,to ensure full compatibility with COTS WiFi,we modulate the physical service data unit.Therefore,data recovery is possible using only commercial NICs.We conduct comprehensive experiments to examine our proposal and experiment results show that AT-Eye achieves a throughput of 10.8 Mbps with COTS radios.We also simulate a 16-way battery-free tag camera system,demonstrating AT-Eye’s feasibility of high-definition video communication.

Extraordinary Electromagnetic Waves in Weakly Relativistic Degenerate Spin-1/2 Magnetized Quantum Plasmas

By using the relativistic quantum magnetohydrodynamic model, the extraordinary electromagnetic waves in magnetized quantum plasmas are investigated with the effects of particle dispersion associated with the quantum Bohm potential effects, the electron spin-1/2 effects, and the relativistic degenerate pressure effects. The electrons are treated as a quantum and magnetized species, while the ions are classical ones. The new general dispersion relations are derived and analyzed in some interesting special cases. Quantum effects are shown to affect the dispersion relations of the extraordinary electromagnetic waves. It is also shown that the relativistic degenerate pressure effects significantly modify the dispersive properties of the extraordinary electromagnetic waves. The present investigation should be useful for understanding the collective interactions in dense astrophysical bodies,such as the atmosphere of neutron stars and the interior of massive white dwarfs.