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Huang Y.,Wuhan University | Huang Y.,Hubei Institute of Aerospace Chemotechnology | Meng X.,Central China Normal University | Gong P.,CAS Technical Institute of Physics and Chemistry | And 3 more authors.
Journal of Materials Chemistry C | Year: 2015

To search for a new nonlinear optical (NLO) material to be used in the mid-IR region with excellent comprehensive performance including high laser damage threshold (LDT), K2SbF2Cl3 has been synthesized by the hydrothermal method, and its potential as such a new material is evaluated for the first time. Its powder shows phase-matchable second harmonic generation (SHG) response of approximately 4 times as strong as that of KH2PO4 (KDP). Its optical band gap is 4.01 eV, which is much wider than the band gaps of the currently commercialised IR NLO crystals. This means that K2SbF2Cl3 will exhibit a much higher LDT. Its powder also exhibits excellent transparency in the range of 0.31-14 μm and good thermal stability. The relationship between the composition, crystal structure and properties is discussed. These results indicate that K2SbF2Cl3 is a promising candidate for IR NLO materials. © 2015 The Royal Society of Chemistry. Source

Lu S.,Hubei Institute of Aerospace Chemotechnology
Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica | Year: 2015

Strain invariant failure theory (SIFT) is a new type of strength theory for composites based on physical failure mode, which is applied to the failure analysis of composite structures widely. In order to improve the accuracy of theoretical analysis, SIFT was extended to be used to analyze the static loading compressive progressive failure mechanism and strength for carbon fiber reinforced polymer (CFRP) composite laminate open-hole structures firstly. The implementation methods of developed SIFT include two parts of material strength characterization and structure strength prediction. The structure strength prediction based on the ABAQUS platform and was realized by using the user defined material subroutine (UMAT) wrote by Fortran scripts. Then, the predicted values of SIFT as well as the predicted results of classical composites strength theories such as Tsai-Wu and Hashin theories were compared with the testing results, and the results showed that the accuracy of SIFT prediction was the best. Meanwhile, based on SIFT, the failure mechanisms evolution from initial failure to final failure of AS4/3501-6 laminate open-hole structures under static loading compression were analyzed in details. Finally, the static loading compressive failure mechanisms of AS4/3501-6 laminate open-hole structures predicted by SIFT were compared with testing results. The results show that the progressive failure mechanisms predicted by SIFT agree well with the testing results. The obtained conclusions provide new thoughts for the strength prediction of CFRP structures. © 2015, BUAA Culture Media Group Ltd.. All right reserved. Source

Gu J.,University of Western Ontario | Gu J.,Hubei Institute of Aerospace Chemotechnology | Hu M.J.,University of Western Ontario | Guo Q.Q.,University of Western Ontario | And 3 more authors.
RSC Advances | Year: 2014

A facile and high-yielding hydrothermal method for synthesizing graphene quantum dots (GQDs) from glucose is presented. The GQDs, with fluorescence quantum yield (FL QY) of 44.3%, demonstrate strong green photoluminescence (PL) and excitation-independent PL emission characteristics. This journal is © the Partner Organisations 2014. Source

Gong S.,York University | Zhu Z.H.,York University | Li J.,York University | Li J.,Hubei Institute of Aerospace Chemotechnology | Meguid S.A.,Kings College
Journal of Applied Physics | Year: 2014

This paper investigated the effect of carbon nanotube (CNT) agglomeration on the electrical conductivity of CNT-polymer composites by experimental characterization and theoretical modeling. The present experimental results show that the acid treatment of CNTs has significantly alleviated the CNT agglomeration in CNT-polymer composites and improved the electrical conductivity of the composites compared with CNT-polymer composites made from the same pristine CNTs. The improvement by the acid treatment is further studied by a multiscale CNT percolation network model that considers the CNT agglomeration based on experimental observation. Numerical results are in good agreement with the experimental data. The smaller the size of CNT agglomerates is in the experiments, the closer the measured electrical conductivity of CNT-polymer composites is to its theoretical limit. The current study verifies that (i) the CNT agglomeration is the main cause that leads to a lower electrical conductivity of CNT-polymer composites than their theoretical limit, and (ii) the current multiscale percolation network model can quantitatively predict the electrical conductivity of CNT-polymer composites with CNT agglomeration. The comprehensiveness of the developed modeling approach enables an evaluation of results in conjunction with experimental data in future works. © 2014 AIP Publishing LLC. Source

Tang G.,Huazhong University of Science and Technology | Tang G.,Hubei Institute of Aerospace Chemotechnology | Wen Y.,Huazhong University of Science and Technology | Pang A.,Hubei Institute of Aerospace Chemotechnology | And 7 more authors.
CrystEngComm | Year: 2014

Distinct from the common well faceted ZnO nanorods (R-ZnO), ZnO nanotetrapods (T-ZnO) exhibited a remarkable catalytic activity for the thermal decomposition of ammonium perchlorate (AP): the activation energy at high temperature decomposition (HTD) was significantly decreased to 111.9 kJ mol -1, much lower than 162.5 kJ mol-1 for pure AP and 156.9 kJ mol-1 for AP with R-ZnO. This was attributed to more abundant atomic steps on the surface of T-ZnO than that of R-ZnO, as evidenced by HRTEM and density function theory (DFT) calculations. It was shown that the initiation step of perchloric acid (PA) decomposition happened much faster on stepped T-ZnO edges, resulting in the formation of active oxygen atoms from HClO 4. The formed oxygen atoms would subsequently react with NH 3 to produce HNO, N2O and NO species, thus leading to an obvious decrease in the activation energy of AP decomposition. The proposed catalytic mechanism was further corroborated by the TG-IR spectroscopy results. Our work can provide atomic insights into the catalytic decomposition of AP on ZnO nanostructures. © 2014 The Royal Society of Chemistry. Source

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