Synthesis of VO2/Poly(MMA-co-dMEMUABr) Antimicrobial/Thermochromic Dual-functional Coating and Reactivity Ratios Study

Antimicrobial/thermochromic dual-functional coatings were successfully synthesized via UV-curing. The quaternary ammonium compound (QAC) N,N-dimethyl-N-{2-[(2-methylprop-2-enoyl)oxy]ethyl}undecane-1-aminium bromide (dMEMUABr) was synthesized and copolymerized with methyl methacrylate (MMA) for antimicrobial properties. Vanadium oxide (VO2) nanoparticles were evenly dispersed within the coating, providing thermochromic properties. The dual-functional coating showed high luminous transmittance (Tlum(25°C) =36.1 %) and solar energy modulation ( Tsol=5.8 %). 90.3 % of bacteria reduction was observed against Escherichia coli within 24 h contact. To further understand the sequence distribution of the copolymer poly(MMA-co-dMEMUABr), the reactivity ratios of MMA and dMEMUABr monomer were studied and compared under thermal and UV initiation copolymerization. In the non-polar solvent chloroform-d, the reactivity ratio of MMA (rMMA=0.06-0.46) was found lower than that of dMEMUABr (rdMEMUABr=6.64-11.51) under thermal copolymerization, which was found consistent for reactivity ratios under UV copolymerization (rMMA=0.73-0.76, rdMEMUABr=4.42-4.48). However, in the polar solvent DMSO-d6, it showed the opposite tendency (rMMA=1.65-1.73, rdMEMUABr=0.24-0.32) attributed to solvent-dMEMUABr monomer interactions

Prevention and Trust Evaluation Scheme Based on Interpersonal Relationships for Large-Scale Peer-To-Peer Networks

Peer reviewedPublisher PD

Resonant modal approximation of time-domain elastic scattering from nano-bubbles in elastic materials

In this paper, we are concerned with the elastic wave propagation in bubbly elastic medium. Due to the nano-bubble with damping, Minnaert resonance can be induced at certain discrete resonant frequencies, which forms the fundamental basis of effectively constructing elastic metamaterials via the composite material theory. We study the approximation of the low-frequency part of the scattered field in the elastic material under wide-band impinging signals in the time domain. By analyzing the asymptotic expansions of the spectrum of the layer-potential operators, and approximating the incident field with a finite number of modes, we first obtain an expansion with a finite number of modes for the acoustic-elastic wave scattering in the time-harmonic regime. Then we define the Minnaert resonance, and show that the low-frequency part of the scattered field in the time domain can be well approximated by using the resonant modal expansion with sharp error estimates. Interestingly, we find that the $0$-th mode is the main contribution to the resonant modal expansion.Comment: 35 page

Quantum Causal Inference with Extremely Light Touch

We consider the quantum version of inferring the causal relation between events. There has been recent progress towards identifying minimal interventions and observations needed. We here show, by means of constructing an explicit scheme, that quantum observations alone are sufficient for quantum causal inference for the case of a bipartite quantum system with measurements at two times. A key technical contribution is the derivation of a closed-form expression for the space-time pseudo-density matrix associated with many times and qubits. This matrix can be determined by coarse-grained quantum observations alone. We show that from this matrix one can infer the causal structure via the sign of a particular function called a causal monotone. Our results show that for quantum processes one can infer the causal structure solely from correlations between observations at different times.Comment: 6+5 pages, 2 figures, Comments are welcom