During the processes of production, storage, transportation and use of hazardous chemicals, acid–alkali corrosive liquid spatter and leakage would cause serious casualties. In order to protect the lives and health of staff, the surface of fabrics should be treated to obtain hydrophobicity and acid–alkali resistance. In this paper, polyester fabric was used as the base cloth, and polydimethylsiloxane (PDMS) and polytetrafluoroethylene (PTFE) micro-powder were used as the functional materials to fabricate waterproof and breathable fabric with good acid–alkali resistance using a method of plasma pretreatment-impregnation- and plasma-induced crosslinking. The effects of PDMS, PTFE powder and plasma-induced crosslinking on the surface and physical and chemical properties of fabric were investigated. It was found that the use of PDMS and PTFE powder had little effect on the mechanical and wearing comfort properties. However, it could significantly improve the acid–alkali resistance, as the liquid repellent rate of the treated fabric surface was higher than 80%, and the penetration index was lower than 2%.
A new Zn(II)-organic framework with 2,2-bipyridine-5,5-dicarboxylate (bpydc) ligand {[Zn(H 2 O)(bpydc)]·CH 3 OH} n was solvothermally obtained, and structurally and photophysically characterized. Structural analysis reveals that the distorted Zn II octahedra are periodically extended by the ditopic bpydc 2 ‒ connector, leading to a coplanar grid-like (4 4) layer. The complex has excellent thermal and environmental stability as well as good dispersion in water system. More interestingly, resulting from the efficient ligand to metal charge transfer, the complex can emit strong blue emission dispersed in water medium and can detect both Cr 2 O 7 2 – and Fe 3+ ions through fluorescence quenching with high quench constants (1.12×10 5 M - 1 and 2.12×10 4 M - 1 ) and low limits of detection (0.54 mM and 1.02 mM). These interesting results suggest that the complex can be potentially served as a promising dual-responsive luminescent sensor material for environmental pollutant monitoring.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Developing a confidence interval for the ratio of two quantities is an important task in statistics because of its omnipresence in real world applications. For such a problem, the MOVER-R (method of variance recovery for the ratio) technique, which is based on the recovery of variance estimates from confidence limits of the numerator and the denominator separately, was proposed as a useful and efficient approach. However, this method implicitly assumes that the confidence interval for the denominator never includes zero, which might be violated in practice. In this article, we first use a new framework to derive the MOVER-R confidence interval, which does not require the above assumption and covers the whole parameter space. We find that MOVER-R can produce an unbounded confidence interval, just like the well-known Fieller method. To overcome this issue, we further propose the penalized MOVER-R. We prove that the new method differs from MOVER-R only at the second order. It, however, always gives a bounded and analytic confidence interval. Through simulation studies and a real data application, we show that the penalized MOVER-R generally provides a better confidence interval than MOVER-R in terms of controlling the coverage probability and the median width.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
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