A Survey of Quantum Lyapunov Control Methods

The condition of a quantum Lyapunov-based control which can be well used in a closed quantum system is that the method can make the system convergent but not just stable. In the convergence study of the quantum Lyapunov control, two situations are classified: non-degenerate cases and degenerate cases. In this paper, for these two situations, respectively, the target state is divided into four categories: eigenstate, the mixed state which commutes with the internal Hamiltonian, the superposition state, and the mixed state which does not commute with the internal Hamiltonian state. For these four categories, the quantum Lyapunov control methods for the closed quantum systems are summarized and analyzed. Especially, the convergence of the control system to the different target states is reviewed, and how to make the convergence conditions be satisfied is summarized and analyzed.Comment: 1

Implicit Lyapunov Control for the Quantum Liouville Equation

A quantum system whose internal Hamiltonian is not strongly regular or/and control Hamiltonians are not full connected, are thought to be in the degenerate cases. The most actual quantum systems are in these degenerate cases. In this paper, convergence problems of the multi-control Hamiltonians closed quantum systems in the degenerate cases are solved by introducing implicit function perturbations and choosing an implicit Lyapunov function based on the average value of an imaginary mechanical quantity. For the diagonal and non-diagonal target states, respectively, control laws are designed. The convergence of the control system is proved, and an explicit design principle of the imaginary mechanical quantity is proposed. By using the proposed method, the multi-control Hamiltonians closed quantum systems in the degenerate cases can converge from any initial state to an arbitrary target state unitarily equivalent to the initial state in most cases. Finally, numerical simulations are studied to verify the effectiveness of the proposed control method. The problem solved in this paper about the state transfer from any initial state to arbitrary target state of the quantum systems in degenerate cases approaches a big step to the control of actual systems. Keywords: perturbations, Lyapunov control, degenerate, convergence, non-diagonal target stat

Surface morphology and mechanical properties of conventional and selfadhesive resin cements after aqueous aging

The stable long-term performance of resin cement under oral environmental conditions is a crucial factor to obtain a satisfactory success of the allceramic dental restoration. Objective: This study aimed at evaluating and comparing the surface morphology and mechanical property of conventional and self-adhesive resin cement after aqueous aging. Materials and Methods: Disc-shaped specimens of 3 conventional (C1: Multilink N, C2: Duolink, C3: Nexus 3) and 3 self-adhesive (S1: Multilink Speed, S2: Biscem, S3: Maxcem) types of resin cements were subjected to irradiation. After 24 h, the Knoop microhardness of each resin cement was evaluated. The specimens were immersed separately in distilled water and maintained at 37°C. A total of 5 specimens of each resin cement were collected at the following time intervals of immersion: 1, 6, 12 and 18 months. The samples were used to evaluate the Knoop parameters of microhardness, sorption and solubility. The surface morphology of the specimens after 18 months of immersion was observed by scanning electron microscopy. The sorption and solubility data were analyzed by two-way ANOVA. The Knoop microhardness was tested by the ANOVA repeated measures (P<0.05). Results: The sorption and solubility parameters of C1 and S1 exhibited significant fluctuations during the aqueous aging. The hardness of the S1 and S2 specimens decreased significantly after an 18-month water immersion. The S1, S2 and S3 specimens indicated higher filler exposure and stripping and apparent pores and cracks compared to specimens C1, C2 and C3, respectively. Conclusion: The surface of selfadhesive resin cements is more susceptible to aqueous damage than that of the conventional resin cements

Fenofibrate-Loaded Biodegradable Nanoparticles for the Treatment of Neovascular Age-Related Macular Degeneration

Fenofibrate-Loaded Biodegradable Nanoparticles for the Treatment of Neovascular Age-Related Macular Degeneration Russell Simmers, Depts. of Physics and Chemistry, with Dr. Qingguo Xu, VCU School of Pharmacy Background: Neovascular age-related macular degeneration (AMD) is a leading cause of visual impairment in the elderly population in the industrialized world. The current treatment for neovascular AMD is anti-vascular endothelial growth factor (anti-VEGF) therapy; however, nearly 40-50% of patients do not fully respond to anti-VEGF therapy. Therefore, non-VEGF therapeutics are required for neovascular AMD treatment. Fenofibrate is a peroxisome proliferator-activated receptor alpha (PPARα) agonist and has demonstrated robust therapeutic effects on neovascular AMD in animal models; however, it must be delivered frequently via intravitreal injection due to quick clearance of the drug from the eye, and may induce injection associated side effects such as retinal detachment, ocular hemorrhage and endophthalmitis. Purpose: To develop and optimize fenofibrate-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (Feno-NP) with high-drug loading and long-lasting drug release profile to effectively treat neovascular AMD for 6-months with one single intravitreal injection. Methods: Feno-NPs were prepared by emulsification method and were fully characterized in terms of particle size, surface charge, morphology and in vitro drug release profiles and the ocular pharmacokinetics studies were performed in rats following intravitreal injection. Efficacy on neovascular-AMD was determined by measuring vascular leakage, vascular permeability, and the numbers of subretinal neovascular (SRNV) and intraretinal neovascular (IRNV) lesions after intravitreal injection of Feno-NPs in a laser-induced choroid neovascularization (CNV) rat model.https://scholarscompass.vcu.edu/uresposters/1387/thumbnail.jp

What do we visually focus on in a World Heritage Site? A case study in the Historic Centre of Prague

Since socio-economic development is associated with artificial construction, heritage environments must be protected and renewed while adapting to such development. Many World Heritage Sites’ visual integrity is endangered by new construction. The paper aims to explore people’s visual focus patterns concerning the integrity of heritage to ensure that traditional culture is not endangered by the construction and development of modern life, and to protect Outstanding Universal Values. In this study, visual heatmaps are generated to investigate people’s visual integrity in the Historic Centre of Prague from micro to macro viewpoints using an eye tracker. We found that humans’ perspectives are unobstructed or concentrated, and the view of main attractions is generally maintained by a buffer zone. However, newly constructed high-rise buildings can result in major visual concerns. Therefore, new buildings with large heights and strong contrasting colours should be restricted to World Heritage Sites. Moreover, complex artistic effects (facade midline, domes, mural painting, faces of sculptures) will likely attract people’s attention. In contrast, visual focus is not concentrated on greenery, roofs and floors. Accordingly, greenery could become a flexible space to serve as a background for buildings and landscape nodes. Furthermore, visual focal factors are associated with two significant aspects: people and the environment. Since people and transportation could pose visual concerns, tourism managers should optimise for characteristics such as controlling the density of pedestrian flow and planning parking spaces. The visual patterns identified could be useful for the design, conservation, and management of visual integrity in cultural heritage sites to avoid the spread of artificial constructions within the boundaries of heritage sites, which may lead to their being endangered or delisted

On the influence factors of audio-visual comfort of mountain landscape based on field surve

This study is aimed to investigate factors that can affect the audio-visual comfort of tourists with a mountainous landscape. The results reveal that the audio-visual comfort of tourists is positively correlated with the percentage of tourists engaged in a dynamic state. In contrast, the audio-visual comfort has strong negative correlations with density, sound pressure level and sound characters including fluctuation and loudness. Overall, respondents in the mountain area find the audio-visual level most comfortable when the ratio of visitors in dynamic states is greater than 33%, the fluctuation of sound is within 0.08 vacil, the loudness of sound is less than 46 sone, the population density is less than 0.822 person/m2, and the sound pressure level is less than 82 dB. Compared with urban areas, a 24 dB increase in the sound pressure level threshold is observed for a positive evaluation of audio-visual comfort in the mountain area