No abstract

A novel energetic composite with low electrostatic sensitivity was successfully synthesised in this work. Copper nanowires decorated reduced graphene oxide (CuNW@rGO) precursor was prepared through a facile one-pot hydrothermal approach. Then the precursor was deposited on silicon substrate by electrophoretic deposition, which greatly reduced the security risks of directly handling of powder sample. Copper azide nanowires(CANW)@rGO was in-situ fabricated by reaction of copper nanowire (CuNW ) @rGO with HN3 gas. The materias were characterized by SEM-EDS, TEM, XRD, DSC and Raman spectroscopy. The electrostatic sensitivity of CANW@rGO composite was investigated by electrostatic sensitivity tester JGY-50III. The discharge energy at 50%(E50%) of CANW@rGO composites with rGO contents of 15 and 25 wt% were 0.92mJ and 1.43mJ, respectively. The results indicate that the electrostatic sensitivity of the as-prepared CANW@rGO energetic composite was highly reduced with the addition of rGO.

In this paper, the biological-aerated filter (BAF) was employed to treat the wastewater containing terephthalic acid (TA). Factors that affected the efficiency of TA and CODCr removal were evaluated experimetally, including pH, hydraulic loading, hydraulic retention time (HRT) and TA volume loading. At pH 7-8, hydraulic loading rate 0.067-0.48 m3/(m2 h), HRT more than 3.5h and TA loading 0.04-0.15g/(m3 d), the TA and CODCr removal efficiency was more than 93% and 87%, respectively. The mathematical model of matrix (TA) was obtained by Monod's relation and the experimental parameters of the model were 1.972 g/(m2d) and 9.782 mg/L.

Purpose As the most common variant of microcystins (MCs), microcystin-LR (MCLR) is a kind of toxins produced by some species of harmful cyanobacteria and more and more attention has been paid to it. Biodegradation has been extensively investigated and recognized to be a cost-efficient and environmentally benign method for MC clean-up. In order to further research the growth characteristics of strain and the biodegradation characteristics of MCLR, it is necessary to use the dynamic mathematical models as powerful and useful tools. Methods In this study, strain CQ5 was screened and identified by morphological observation, physiological and biochemical tests, and 16S rDNA sequence analysis. The kinetic models of cell growth and MCLR degradation were established with the Gompertz model and revised Monod kinetic model. ResultsThe results showed that strain CQ5 had the closest phylogenetic similarity to Lysinibacillus boronitolerans (T-10a, AB199591) in the phylogenetic tree, with 99% bootstrap support. Strain CQ5 could utilize MCLR as the carbon and nitrogen source for growth. When the initial pH value was 7 and the inoculation amount was 3%, strain CQ5 grew well in MSM, in which the MCLR crude extract was used as the carbon and nitrogen source of strain CQ5. Within 244 h, the MCLR concentration changed from 14.12 to 1.57 μg/L and its degradation rate could reach 88.88%. The growth curve fitted with the Gompertz growth model (N t = 1.3119 * exp(−0.1237 * exp(−6.6341t)), R 2 > 0.99). The process of MCLR degradation agreed with the first-order reaction kinetic equation (lnS = 2.64764 − 0.01537t, R 2 > 0.99). The linkage relationship between MCLR concentration, cell density, and MCLR degradation rate was consistent with the revised Monod equation (V = 0.342S, R 2 > 0.97) at low substrate concentration, where V max / K s was 0.342. The dynamic relationship in which strain CQ5 degraded MCLR and used it as the carbon and nitrogen source to promote its own growth could be explained by the equation S = 14.12 e − 0.342 Nt (N = 1.08). ConclusionThe growth of strain CQ5 and MCLR concentration in degradation system could be simulated and predicted by the dynamic mathematical models in this study. And the predicted results were very consistent. These results could provide theoretical reference for studying the mechanism of MCLR biodegradation and promote the engineering application of strain CQ5.

The storage stability of energetic materials is important for their application. In our previous work, Al/CuO nanothermites was applied to a MEMS-based solid propellant micro thruster (SPM) array because of its short ignition delay and high reaction rate. In the current work, the storage stability of Al/CuO nanothermites, which were prepared by electrospray method and stored with different storage time, was systematically researched. The activation energy of Al/CuO nanothermites were measured by DSC. The ignition temperature and the curve pressure history of Al/CuO nanothermites were measured using T-jump and constant-volume pressurization tests, respectively. Further, the nanothermites were characterized by XRD, XPS, SEM and TEM. The results show that the morphology and mixture uniformity of the nanothermites after a long-time storage did not change significantly. The slow decomposition of NC and the thickening of oxide layer of Al NPs existed in the storage of Al/CuO nanothermites, analysed by XPS. The activation energy (Ea ) of Al/CuO nanothermites after storage for different time was determined using the method of Kissinger, as shown in Figure 1. Ea was decreased from 272.8 kJ/mol to 154 kJ/mol after storage for 13 months. When stored for 0, 7 and 13 months, the peak pressures of Al/CuO nanothermites were 685.8 kPa, 626.3 kPa and 625.5 kPa, respectively. In addition to the ignition temperature, it was 775 °C, 739 °C and 754 °C, respectively. This result indicated that the ignition and combustion properties of Al/CuO nanothermites are obviously reduced when stored for a long time, at room temperature. The full version of this extended abstract will appear in Defence Technology in 2020.