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To research serious nonlinear coupling problems among aerodynamics, flight mechanics, and flight control during high maneuvers, a virtual flight testing platform has been developed for a large-scale, high-speed wind tunnel, based on the real physical environment, and it can significantly mitigate risks and reduce the costs of subsequent flight tests. The platform of virtual flight testing is composed of three-degrees-of-freedom model support, measuring devices for aerodynamic and motion parameters, a virtual flight control system, and a test model. It provides the ability to realistically simulate real maneuvers, investigate the coupling characteristics of unsteady aerodynamics and nonlinear flight dynamics, evaluate flight performance, and verify the flight control law. The typical test results of a pitch maneuver with open-loop and closed-loop control are presented, including a one-degree-of-freedom pitch motion and a two-degrees-of-freedom pitch and roll motion. The serious pitch and roll-coupled motion during a pitch maneuver at a high angle of attack is revealed, and the flight control law for decoupled control is successfully verified. The comparison of the test results and the flight data of a real pitch maneuver proves the reliability and capability of virtual flight testing. [ABSTRACT FROM AUTHOR]

Catalysts based on different halo‐alkanes structures with durable catalytic performance were synthesized and applied to the Friedel–Crafts alkylation of long‐chain alkenes (mixed C16–24 olefins) with toluene. Surprisingly, compared with the usual industrial catalysts (~10 runs), the cyclic times of the ionic liquid (IL) catalysts reached up to 24 runs, which greatly promotes the industrialization process. Then, Lewis acids of catalysts with different precursor/AlCl3 molar ratios were investigated and a close relation was discovered between the Lewis acid and catalytic activity. In addition, a comparison of the different halo‐alkanes structures about those catalysts was made. The results showed that the [C6Et3N]Cl–AlCl3 had the strongest Lewis acid, corresponding to the highest catalytic performance. Also, the structures of precursors and the specific gravity and active site species of catalysts were investigated by Fourier transform infrared and Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR). Meanwhile, the various parameters (catalyst dosage, toluene/olefin molar ratio, reaction temperature and reaction time) of long‐chain alkenes alkylation with toluene were studied. Finally, under the optimized reaction conditions, the conversion and selectivity of long‐chain alkenes alkylation reached 99.92 and 32.99%, respectively. [ABSTRACT FROM AUTHOR]

Flower-like P-doped graphitic carbon nitride (g-C3N4) with a high surface area and porosity has been prepared via a facile, template-free, cost-effective and thermal copolymerization route, using phosphoric acid as the phosphorus source and a cyanuric acid–melamine complex as the supramolecular precursor. It could be found that phosphoric acid could stabilize the three-dimensional character of the as-prepared P-doped g-C3N4 and the g-C3N4 micro-flower consisted of ultrathin nanosheets which possessed abundant mesopores. The unique structure, combined with phosphorus heteroatom doping, promoted the utilization of visible light and improved the separation and mobility of photogenerated charges. The obtained P-doped g-C3N4 exhibited prominent photocatalytic performance in the water splitting for the hydrogen evolution reaction under visible light irradiation. The hydrogen evolution rate reached 256.4 μmol h−1, almost 24 times higher than that of pristine g-C3N4. Meanwhile, a possible mechanism for photocatalytic hydrogen evolution was proposed according to the results. [ABSTRACT FROM AUTHOR]

A series of bipolar hosts based on carbazole and phenyl benzimidazole (PBI) moieties, collectively named xCz–nPBI, were designed and synthesized. On the basis of different numbers, ratios and link-configurations of the functional groups, the influence of substitution on the chemical, photophysical and electrochemical properties of the host materials were investigated in detail. Both DFT calculations and single carrier devices demonstrate that the strategy of introducing more electron-withdrawing PBI groups in the molecules can effectively enhance the electron injection and transport ability of the bipolar host, while an increased number of carbazole units endows the hosts with a much smaller ΔEST for efficient hole injection at the cost of sacrificing their charge balance property. As a result, the solution-processed green-emitting PHOLEDs based on Cz–6PBI show an extremely low turn on voltage of 2.9 V and the highest current and power efficiency of 47.8 cd A−1 and 29.6 lm W−1, respectively. Even at luminance as high as 1000 cd m−2, their efficient roll-off was only 4.2%, which was far better than the 6Cz–PBI host device. Because the T1 energy levels and triplet state locations of these hosts are similar, their ΔEST and charge balance property should be the main factors that influence their EL performances. We conclude that it is not necessary to achieve a very small ΔEST by introducing more carbazole moieties at the cost of weakening of electron transporting ability. As for solution-processed devices, which suffer from solvent impurities and oxygen diffusion induced strong electron trapping effect, a systemic increase in the number of electron-withdrawing PBI groups in their host materials can significantly enhance the charge balance of their emission layers (EMLs) for highly power efficient solution-processed PHOLEDs. [ABSTRACT FROM AUTHOR]

A heterogeneous catalyst (HPW/mpg‐C3N4) for the alkylation of o‐xylene and styrene reaction was acquired by the immobilization of phosphotungstic acid (HPW) on mesoporous graphitic carbon nitride (mpg‐C3N4) through electrostatic interaction. The results of Fourier transform infrared spectroscopy (FT‐IR), X‐ray powder diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) proved that HPW was successfully immobilized on the protonated mpg‐C3N4 by electrostatic interaction. The textural properties and morphology of HPW/mpg‐C3N4 were characterized by N2 adsorption–desorption, scanning electron microscopy (SEM). Among them, 40% HPW/mpg‐C3N4 displays the best catalytic performance in the alkylation reaction with 91.8% yield and 96.5% selectivity to 1, 2‐diphenylethylane. Moreover, protonated mpg‐C3N4 not only displays as a support to facilitate great dispersion of HPW but also promotes the alkylation product diffusion effectively. Besides, the HPW/mpg‐C3N4 catalyst could be recycled easily without significant loss of catalytic activity, which is demonstrate by the recyclability of HPW/mpg‐C3N4 catalyst test. [ABSTRACT FROM AUTHOR]