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An efficient organocatalytic system was developed for the synthesis of cyclic carbonates from epoxides and CO2 (25–45 °C, 1 atm) in high-to-excellent yields (85–97%). Moreover, the 2,6-pyridinedimethanol system could be recycled several times without significant loss of activity.

Lithium-rich layered oxide materials are extremely important for improving the energy density of lithium-ion batteries. However, the electrochemical kinetics and cycle stability of these materials are still not good enough for further industrial application. Here, the effects of Nb doping on the crystalline structure, surface chemistry, cycle stability, and electrochemical kinetics of Li1.13Mn0.52Ni0.26Co0.10O2 are studied. Results show that Nb doping can significantly promote the cycle stability and electrochemical kinetics of Li1.13Mn0.52Ni0.26Co0.10O2. After 200 cycles, the discharge capacity retention increases from 59.2% (pristine material) to 78.8% (1% Nb element doping) with obvious enhanced rate performance. Via X-ray diffraction, scanning electron microscope, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and galvanostatic intermittent titration analysis, it is confirmed that Nb element has been successfully doped into the bulk of Li1.13Mn0.52Ni0.26Co0.10O2. Doping sites of Nb element in structure and influence on lithium migration has also been studied by the Rietveld refinement and first principle theoretical calculation methods. Doped Nb element efficiently changes the lattice parameters, inhibits the resistance rise, accelerates lithium ion diffusion, and finally promotes the cycle stability, and electrochemical kinetics of Li1.13Mn0.52Ni0.26Co0.10O2.

This study attempts resolution of certain ambiguities of the corporate elite -Chief Executive Officer (CEO) and Top Management Team (TMT) -effect on corporate internationalization strategy. This work hypothesized that curvilinear relationship exists between CEO position tenure, TMT size, and TMT tenure heterogeneity and a firm's internationalization, by combining previous upper echelon theory and processing international business school perspective. Our detailed empirical findings indicate that CEO and TMT characteristics show a nonlinear relationship, based on 165 samples of Taiwanese firms operating in a technologically intensive industry. An inverted U-shaped relationship exists between CEO position tenure and TMT size regarding a firm's internationalization. These associations are an inverted U-shape, when internationalization level facing TMT tenure heterogeneity is accounted for.

A new cationic polythiophene derivative poly[3-(1,1 ′ -dimethyl-4-piperidinemethylene)thiophene-2,5-diyl chloride] (PDPMT-Cl) is synthesized and applied as a colorimetric and fl uorometric probe for the detection of iodide ion and anionic surfactants with high selectivity and sensitivity. Upon adding iodide ion or anionic surfactant into the aqueous solution of PDPMT-Cl, the maximum absorption of the polymer is blue-shifted with a naked-eye color change from red-violet to yellow, signifying that iodide ion or anionic surfactants can cause the dissociation of PDPMT-Cl aggregates. More sensitive results are obtained in the fl uorometric detection to iodide ion or anionic surfactant, thereinto, the detection limit to surfactants can be extended to the order of 10 − 9 M . applied to colorimetric probes for the detection of various bioanalytes. [ 1 − 8 ] However, few of them can be used to detect anionic substrates and the number of colorimetric sensors available at present for anionic substrates remains quite limited. The well-known anionic substrates detection techniques, such as capillary electrophoresis, [ 9 − 15 ] ion chromatography, [ 16 ] normal Raman spectroscopy, [ 17 ] gas chromatography/mass spectrometry (GC-MS), [ 18 ] highperformance liquid chromatography (HPLC), and fl uorescent detection (based on synthetic receptors), [ 19 , 20 ] to some extent, exist some limitations, including time-consuming, requiring expensive equipment, poor selectivity, and sensitivity. Therefore, it is the need of the hour to design new approaches that could improve simplicity, selectivity, and sensitivity.Many systems capable of recognizing, sensing, and transporting negatively charged species are based on supramolecular chemistry. Miyaji et al. [ 21 ] ever reported colorimetric detection of anions by calix[4]pyrrole, but it couldnot monitor the exact concentration, resulting in the limitation of its application. Moreover, though using polymeric membranes doped with various metalloporphyrins or polypyrroles to detect anions were also reported, [ 22 , 23 ] all of them were not still ideal enough to apply. However, E. Li et al.