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Non-centrosymmetric (NCS) structure is an indispensable prerequisite for second-order nonlinear optical (NLO) material. Currently, the mainstream approach for designing new NCS structures still relies on chemical substitution, necessitating an urgent infusion of fresh ideas. In this work, two isomorphic sulfides AeMn6Ga6S16 (Ae = Ca, 1; Sr, 2) are afforded by modifying the skeleton of centrosymmetric (CS) Mn2Ga2S5via introducing strong electropositive alkaline-earth cations. Concretely, the incorporation of Ca2+/Sr2+ cations allows the elementary [MnGaS9]∞ chains to reconfigure into bumpy [MnS6]-[GaS4] layers in a new engagement manner, thus enabling the conversion from CS to NCS structure. Such modifications cause not only strong second-harmonic generation (SHG) responses (∼1.5 × benchmark AgGaS2 @1,700 nm), but also significantly feasible bandgaps (2.60–2.64 eV) compared to the sulfide Mn2Ga2S5 (1.36 eV), which ultimately facilitate ultrahigh laser-induced damage thresholds (4.4–6.6 × AgGaS2 @1,064 nm for compounds 1 and 2). The present study offers an ingenious approach for the transformation of CS to NCS structure. [ABSTRACT FROM AUTHOR]

In this study, integrate electrical resistivity tomography (ERT) tests were carried out in a large-scale (5.0 × 4.0 × 7.5 m) MSW landfill cell to investigate the possibility of detecting perched leachate mounds, leachate level, and gas accumulation zones at wet landfills. The resistivity of both bulk waste and waste components at different moisture states were measured and the three-phase volumetric relationships of the waste pile were analyzed to better interpret the ERT test results in the large-scale cell. The following observations were given: (1) The relationship between resistivity and volumetric moisture content (VMC) of waste sample can be reasonably fitted by Archie's law. The resistivity of waste components at a saturated state was all lower than 21 Ω m. (2) A significant amount of void gas was entrapped in the underwater waste, being 30.4–34.8% of the whole waste pile in volume. (3) Low-resistivity zones (< 5.0 Ω m) were observed in the waste pile being fully drained under a gravity condition, which was believed to be related to a perched leachate. (4) The average VMC values of the waste layer below and above the leachate level were in the ranges of 46.5–53.1% and 28.1–41.3%, respectively. (5) Irregular variations of high-resistivity zones (> 40 Ω m) observed in the underwater waste were associated with the accumulation and dissipation of gas pressure. It was found that the "gas-breaking value" in the gas accumulation zone was up to 10.5 kPa greater than the pore liquid pressure in the stable methanogenesis stage. These findings shone a light on the possibility of using the ERT method as an efficient tool for mapping the gas/leachate distribution and improving operations at wet landfills. [ABSTRACT FROM AUTHOR]

Invariant moment is a highly concentrated and distortion invariant image features. The goal of multi-moving object characterization and classification methods is to find a suitable description of different kinds of moving objects in the scene and match the similarity between unknown moving objects with invariant moment. This paper presents evolution and development of invariant moments family history, and designs a classification model to classify multi-moving objects. Experimental results show that this method can effectively improve the recognition rate of the moving object. [ABSTRACT FROM AUTHOR]

Synergistic photoredox and copper catalysis confers new synthetic possibilities in the pharmaceutical field, but is seriously affected by the consumptive fluorescence quenching of Cu(II). By decorating bulky auxiliaries into a photoreductive triphenylamine-based ligand to twist the conjugation between the triphenylamine-based ligand and the polar Cu(II)–carboxylate node in the coordination polymer, we report a heterogeneous approach to directly confront this inherent problem. The twisted and polar Cu(II)–dye conjunction endows the coordination polymer with diode-like photoelectronic behaviours, which hampers the inter- and intramolecular photoinduced electron transfer from the triphenylamine-moiety to the Cu(II) site and permits reversed-directional ground-state electronic conductivity, rectifying the productive loop circuit for synergising photoredox and copper catalysis in pharmaceutically valuable decarboxylative C(sp3)–heteroatom couplings. The well-retained Cu(II) sites during photoirradiation exhibit unique inner-spheric modulation effects, which endow the couplings with adaptability to different types of nucleophiles and radical precursors under concise reaction conditions, and distinguish the multi-olefinic moieties of biointeresting steride derivatives in their late-stage trifluoromethylation-chloration difunctionalisation. Synergistic photoredox–copper catalysis is limited by fluorescence quenching of Cu(II) ions to photoreductive dyes in solution. Here, the authors compromise photoreduction and Cu(II) catalysis by diode-like coordination polymer with twisted Cu(II)–dye conjugation, revealing its vast application vistas. [ABSTRACT FROM AUTHOR]