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Novel thioxanthone (TX) derivatives are used as versatile photoinitiators upon visible light-emitting diode (LED; e.g., 405, 425, and 450 nm) exposure. The mechanisms for the photochemical generation of reactive species (i.e., cations and free radicals) produced from photoinitiating systems based on the photoinitiator and an iodonium salt, tris(trimethylsilyl)silane, or an amine, were studied by UV–vis spectroscopy, fluorescence, cyclic voltammetry, steady-state photolysis, and electron spin resonance spin-trapping techniques. The reactive species are particularly efficient for cationic, free radical, hybrid, and thiol-ene photopolymerizations upon LED exposure. The optimized photoinitiating systems exhibit higher efficiency than those of reference systems (i.e., isopropyl TX-based photoinitiating systems), especially in the visible range. According to their beneficial features, these photoinitiating systems have considerable potential in photocuring applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017

In this paper we present an end-to-end framework for addressing the problem of dynamic pricing (DP) on E-commerce platform using methods based on deep reinforcement learning (DRL). By using four groups of different business data to represent the states of each time period, we model the dynamic pricing problem as a Markov Decision Process (MDP). Compared with the state-of-the-art DRL-based dynamic pricing algorithms, our approaches make the following three contributions. First, we extend the discrete set problem to the continuous price set. Second, instead of using revenue as the reward function directly, we define a new function named difference of revenue conversion rates (DRCR). Third, the cold-start problem of MDP is tackled by pre-training and evaluation using some carefully chosen historical sales data. Our approaches are evaluated by both offline evaluation method using real dataset of Alibaba Inc., and online field experiments starting from July 2018 with thousands of items, lasting for months on Tmall.com. To our knowledge, there is no other DP field experiment using DRL before. Field experiment results suggest that DRCR is a more appropriate reward function than revenue, which is widely used by current literature. Also, continuous price sets have better performance than discrete sets and our approaches significantly outperformed the manual pricing by operation experts., 9 pages, 7 figures

This work proposes a method to utilizing the third-harmonic magnet shaping to increase the output torque but not the torque ripple in a radial magnetized surface-mounted permanent magnet (SPM) machine with the sinusoidal magnetic pole. The optimal amplitude of the third harmonic injected into the sinusoidal magnetic pole can be obtained through finite element (FE) scanning or analysis. As for the magnetic pole of the SPM machine, it can be arc-shaped or bread-shaped. For the radial magnetized SPM machine with the arc-shaped pole, the optimal amplitude of the third harmonic injected into sinusoidal magnetic pole is 1/6 of the fundamental wave0, while for the radial magnetized SPM machine of the bread-shaped pole, the optimal value varies with the number of pole pairs (p), magnet thickness and rotor radius. Therefore, the previously-derived third-harmonic analytical model is not accurate enough to be useful for the SPM machine with the bread-shaped magnetic pole. For this reason, this paper presents an analytical model for injecting the optimal third harmonic into the sinusoidal bread-shaped pole of the radial magnetized SPM machine. The model can improve the torque to the largest extent without increasing the torque ripple. The model is proved to be accurate by the FE analytical method.

Two D-π-A-type aryl dialkylsulfonium salts with substituted-fluorene as a conjugated system were developed as one-component, versatile photoinitiators under soft irradiation conditions (365–450 nm Light-emitting diodes). The mechanisms for photochemical generation of reactive species (cations and radicals) by the photoinitiators were studied by UV–Vis spectroscopy, theoretical calculations, fluorescence spectroscopy and cyclic voltammetry techniques. The high quantum yields for acid generation (ΦH+ = ∼0.43 to 0.63) of the compounds enable the cationic polymerizations of epoxides and vinyl ether to proceed effectively. Meanwhile, the photocleavage products of sulfoniums (i.e., radicals) initiate the free radical polymerization of acrylate. Such versatile properties allowed them to serve as effective photoinitiators for the synthesis of interpenetrated polymer networks and thiol-ene polymerization without any co-initiators or additives. Based on their beneficial features, these photoinitiators hold great promise for use in photocuring applications.

An efficient strategy for comprehensive utilization of the conjugated sulfonium salt photoacid generator (PAG), namely, 3-{4-[4-(4-N,N′-diphenylamino)-styryl]phenyl}phenyl dimethyl sulfonium hexafluoroantimonate, was developed through photoinitiated cationic photopolymerization (CP) of epoxides and vinyl ether upon exposure to near-UV and visible light-emitting diodes (LEDs; e.g., 365, 385, 405, and 425 nm). Photochemical mechanisms were investigated by UV–vis spectra, molecular orbital calculations, fluorescence, cyclic voltammetry, and electron spin resonance spin-trapping analyses. Compared with commercial PAGs, the prepared conjugated sulfonium salt generated H+, which can be used as photoinitiator. Moreover, the fluorescent byproducts from photodecomposition can be used as photosensitizer of commercial iodonium salt in the photoinitiating systems of CP. These novel D-π-A type sulfonium-based photoinitiating systems are efficient (epoxide conversion = 85–90% and vinyl conversion >90%; LEDs upon exposure to 365–425 nm) even in low-concentration initiators (1%, w/w) and low curing light intensities (10–40 mW cm−2). © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2722–2730

Two novel branched sensitizers bearing biphenyl or fluorenyl groups as the linking skeleton and triphenylamine-stilbene-thiomethyl benzonitrile as peripheral branches were designed. Strong absorption of light in the UV–vis range (λmax = 389–397 nm, emax = 60,200–90,300 M−1 cm−1) matched the emission of new light sources, i.e., UV–vis light-emitting diodes at 365–450 nm. The reactive species produced from the photoinitiating systems based on these chromophores themselves or combined with an iodonium salt, N-vinylcarbazole, or an amine were highly efficient for versatile photopolymerizations (radical, cationic, and thiol-ene polymerizations) upon soft exposure conditions (365–450 nm light-emitting diodes). The UV–vis spectra, theoretical calculation of molecular orbitals, electrochemistry, and fluorescence quenching measurements were studied to reveal the photochemical mechanism.

The iatrogenic cause of bile duct stone formation is mainly due to suture materials, especially silk sutures. In recent years, Prolene and Vicryl sutures have been widely used in biliary surgery, and bile duct stone formation related to sutures are seemingly becoming rare, as there has only been one report of bile duct stone formation caused by Prolene sutures in the literature. In the last few years we have had two cases of Prolene suture-related bile duct stone formation within our unit. We therefore suggest that Vicryl sutures should be used as the first choice in biliary surgery, in order to prevent the formation of iatrogenic bile duct stones.

Muscarinic acetylcholine receptors (mAChRs) comprise five distinct subtypes denoted M1 to M5. The antagonism of M2 subtype could increase the release of acetylcholine from vesicles into the synaptic cleft and improve postsynaptic functions in the hippocampus via M1 receptor activation, displaying therapeutic potentials for Alzheimer’s disease. However, drug development for M2 antagonists is still challenged among different receptor subtypes. In this study, by optimizing a scaffold from virtual screening, we synthesized two focused libraries and generated up to 50 derivatives. By measuring potency and binding selectivity, we discovered a novel M2 antagonist, ligand 47, featuring submicromolar IC50, high M2/M4 selectivity (~30-fold) and suitable lipophilicity (cLogP = 4.55). Further study with these compounds also illustrates the structure–activity relationship of this novel scaffold. Our study could not only provide novel lead structure, which was easy to synthesize, but also offer valuable information for further development of selective M2 ligands.

Root-induced changes play a crucial role in influencing the fate and speciation of potentially toxic elements (PTEs) in contaminated soils, but their role in the phytostabilization of waste slag sites remain unclear. The aim of this study was to determine the effect of four phytostabilization plants, Broussonetia papyrifera, Arundo donax, Robinia pseudoacacia, and Cryptomeria fortunei, planted in a zinc smelting waste slag site for 5 years on PTEs speciation and the mineral and aggregation characteristics at the interface of the waste slag-plant system. The results showed that the presence of a higher content of oxalic acid in the rhizosphere slags of the four plant species than in the bare slag. Revegetation of the waste slag with the four plant species significantly changed the mineral composition and morphology of the waste slag. The mass percentage of large particles (1-5 mm) and small particles (0.5-1 mm, 0.25-0.5 mm, and0.25 mm) in the rhizosphere slags decreased and increased, respectively. The PTEs (Cu, Pb, Zn, and Cd) in most of the rhizosphere slags were mainly distributed within the small particles, and the enrichment coefficients of PTEs in the large particles and small particles were less than and greater than 1, respectively. The bioavailability of the PTEs in the waste slag increased with decreasing particle size. Root-induced the transformation of acid-soluble PTEs into their reducible, oxidizable, and residual forms in the different waste slag particles weathered in the rhizosphere. These results suggested that there are root-induced changes in the aggregation characteristics and geochemical behaviours of PTEs in waste slag fractions during the phytoremediation of waste slag sites.