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A facile and economical approach was developed for the large-scale production of powdered core-shell structured PTFE/Al (CS-PA) energetic materials through ultrasonic-assisted mixing. The low-cost micrometer-sized PTFE and Al particles were used as starting materials. Under high-power ultrasonic waves, the PTFE powder was dispersed into nano-to sub-micrometer-sized particles and then encapsulated the Al microparticles to form the core-shell structure. The heat of combustion, burning rate, and pressurization rate of the powdered CS-PA were measured. The thermal-initiated reaction behavior was further evaluated using thermogravimetry-differential scanning calorimetry. Subsequently, the bulk CS-PA with a uniform microstructure was obtained via cold isostatic pressing of the powdered CS-PA followed by vacuum sintering. For the bulk CS-PA, the quasi-static compression behavior was characterized, and the impact-initiated reaction processes were conducted using the Split Hopkinson Pressure Bar (SHPB) and evaluated by a high-speed camera. Compared to physically mixed PTFE/Al materials, the powdered and bulk CS-PA demonstrated enhanced thermal- and impact-initiated reaction characteristics respectively, proving the effectiveness of our approach for constructing core-shell structures.

Due to the effect of unit stages, the gas-liquid flow and the interphase forces in the multistage multiphase pump are more disordered, which will affect the energy conversion efficiency. However, the characteristics of phase interaction and gas holdup in such a pump are not clear. In this study, based on a modified Euler two-fluid model, simulations of a multiphase rotodynamic pump with two stages were carried out with medium combinations of air-water and air-crude. The characteristics of phase interaction and gas holdup were analyzed at different inlet gas void fractions (IGVFs), and inlet bubble diameters. The results show that the overall changing trend of interphase forces is the same between the first and second stages at different IGVFs, but the magnitudes of interphase forces in the second stage are slightly smaller, especially for the medium combination of air-water. Moreover, the drag is more sensitive to the IGVF, while the lift and added mass force are more sensitive to the medium viscosity. As the increase of the inlet bubble diameter, the difference of the gas holdup effect in the pump increases gradually at IGVF = 9.0%, and the maximum almost occurs in the first stage guide vane (S1). When the bubble diameter increases to 0.7 mm, the degree of gas accumulation and gas-liquid velocity difference increase significantly, resulting in a significant increase of the disordered degree of lift and added mass force.

To explore non-linear flow behaviour in porous media, e.g., packed bed of particles, this study focuses on the prediction of pressure drop/gradient by establishing empirical relations for Forchheimer coefficients based on artificial neural network (ANN) development. To facilitate this process, a large set of experimental data for pressure drop of water flow in various porous media is collected: part from the present experiment and other from those available in the literature. The newly generated ANN model is developed by considering the key influencing factors such as particle density, diameter, and shape, and column porosity. The new model shows excellent performance on the prediction of flow behaviour over previous empirical formula, which is attributed to the ANN's advantages on considering the inter-factor connections and their influences on the results. This proposed approach can provide a new means for analysing the nonlinear flow regime through porous media based on limited dataset.

A pumped hydro storage energy station (PHES) is an effective and reliable station which was quickly develop. To obtain better performances, blade leans have been employed recently on pump-turbine runners. To figure out the effect of the blade leans in turbine mode, numerical simulations were performed on two blade-leaned and no-leaned runners in this work. Because blade leans were on high-pressure edges, the vaneless space was paid chiefly attention. Distinctions due to the blade leans can be found in the spanwise direction. Amplitudes of the component of blade passing frequency in pressure fluctuations show nonuniformity at different vertical locations. While in no-leaned runners, the amplitudes are almost the same. It shows close correlations between the pressure fluctuations and blade leans. In addition, this difference was more prominent in the S-shaped region. The conditions were attributed to the different separations at the inlets of runners. Separations located at the pressure side of the blades and developed vortexes located near the hub, the shroud and at the middle span for runners respectively. The vortexes generated low-pressure areas producing a higher fluctuation in the vaneless space with the same frequency of blade passing when they rotated with the runner.

Nano-ZSM-5 with large amount and high strength of acid sites were successfully synthesized by hydrothermal crystallization of pure-silica nucleus in NaAlO2 alkali solution. The concentration of NaAlO2 alkali solution was decreased by increasing the H2O/Al ratio from 200 to 2600, which strongly determined the acidic properties and crystal size of the obtained nano-ZSM-5. Low concentration of NaAlO2 alkali solution was found unfavorable for the incorporation of Al into the bulk of ZSM-5 crystal in crystallization process. Hence, more Al distributed at the exterior of crystals, which enhanced the accessibility of the acid sites during reaction. Large amount and high strength of acid sites were produced for nano-ZSM-5 by increasing H2O/Al ratio. When the H2O/Al ratio increased from 200 to 2600, the total amount of acid sites increased from 0.59 to 0.81 mmol g−1, much higher than conventional value of 0.50 mmol g−1. In addition, the acid strength increased and the ratio of Bronsted/Lewis acid sites were sharply increased from 2.3 to 4.1 when the H2O/Al ratio increased. Moreover, the size of nano-crystal was also decreased by above decreasing the concentration of the NaAlO2 alkali solution. When the H2O/Al ratio was 2600, the obtained sample possessed total acid amount of 0.81 mmol g−1 and crystal size of 60 nm, respectively. Methanol to hydrocarbon (MTH) reaction results showed that the increased acid sites of the catalyst decreased its catalytic lifetime to some extent, but the aromatics selectivity was tunable obviously. As for the catalyst prepared with H2O/Al ratio of 2000, the aromatics selectivity of the obtained catalyst reached to 66.0%. This paper provided a method for the fabrication of small-size nano-ZSM-5 with large amount and high strength of acid sites and regulated Al distribution for MTH reaction.

Weak interfacial activity and poor wettability between fiber and matrix are known to be the two main factors that restrict the mechanical properties of carbon fiber-reinforced composites (CFRCs). Herein, inspired by high strength and toughness characteristics of wing feathers of Black Kite (

LncRNA (long noncoding RNA) is often dysregulated in tumors especially hepatocellular carcinoma (HCC). However, the dysregulation mechanism of lncRNAs is largely unknown. Here, we showed that lncRNA lncAY expression was stimulated in HCC by either endogenous or exogenous sulfatide. Elevated lncAY promoted HCC cell migration or angiogenesis, whereas lncAY silence suppressed HCC cell migration and proliferation. Interestingly, the activity of lncAY gene promoter was enhanced by sulfatide. Then Myb and MEF2C were identified as the transcription factors responsible for the stimulation of lncAY promoter activity and transcription by sulfatide. Both Myb and MEF2C enrichment on lncAY promoter was further confirmed, and their occupancy on lncAY promoter was strengthened by sulfatide for Myb or MEF2C was acetylated. Mutant Myb-K456A exhibited reduced acetylation and weak stimulation for lncAY transcription. However, Myb mutation K456/503A prevented Myb from acetylation induced by sulfatide. The mutant Myb K456/503A further was unable to occupy lncAY promoter and enhance lncAY transcription. In conclusion, this study demonstrated lncAY transcription was abnormally upregulated by sulfatide in HCC through Myb/MEF2C to promote HCC progression.

This paper deals with a new concept by combining a monopile type wind turbine and a heave-type wave energy converter, that is referred as the ‘MWWC’ (Monopile-WT-WEC- Combination) system herein. Hydrodynamic responses of the MWWC system under typical operational seas cases have been investigated by using both time-domain numerical simulations and scale model tests (1:50). For the numerical model, hydrodynamic loads of the monopile and the WEC are calculated by the AQWA code, which is available for modeling multi-body systems including both mechanical and hydrodynamic couplings between the TLP and the WEC. The scale model tests have been done in State Key Laboratory of Costal and Offshore Engineering (SLCOE). The power-take-off (PTO) system of the WEC device is simulated by two nonlinear air-dampers. Main hydrodynamic characteristics of the MWWC system under typical operational sea cases have been clarified. The obtained wave power characteristic and maximum PTO damping force of the WEC are very helpful for the optimal design of the operational performance of the PTO system. Numerical and experimental results are presented and compared, and good agreements are achieved.

Three pyrazole-3-carboxylic acid (H 2 pca) complexes, Cr(Hpca) 3 ·2H 2 O ( 1 ), Ni 2 (pca) 2 (H 2 O) 6 ·2H 2 O ( 2 ) and [Pb 2 (Hpca) 4 ] n ( 3 ), have been synthesized and fully characterized. The single crystal X-ray diffraction indicate that the mononuclear Cr(III) cation in complex 1 and binuclear Ni(II) cations in complex 2 are coordinated by pyrazole-3-carboxylic acid ligands and water molecules in a distorted octahedral geometry and the binuclear Pb(II) cations in complex 3 presents a distorted seven-coordinated {PbN2O5} pentagonal-bipyramid geometry. Notably, these complexes as effective heterogeneous catalysts show efficient catalytic activities for Knoevenagel condensation (yield up to 97%) and the catalyst can be recycled without losing activity.

The wind energy resource is considerably rich in the deep water of China South Sea, where wind farms have to face the challenge of extreme typhoon events. In this work, the typhoon effect on the aerodynamic performance of the 5MW OC3-Hywind floating offshore wind turbine (FOWT) system has been investigated, based on the Aero-Hydro-Servo-Elastic FAST code. First, considering the full field observation data of typhoon “Damrey” is a long duration process with significant turbulence and high wind speed, so one 3-h representative truncated typhoon wind speed time history has been selected. Second, the effects of both the (variable-speed and collective-pitch) control system of NREL 5 MW wind turbine and the motion of the floating platform on the blade aerodynamic performance of the FOWT system during the representative typhoon time history has been investigated, based on blade element momentum (BEM) theory (coupled with potential theory for the calculation of the hydrodynamic loads of the Spar platform). Finally, the effects of different wind turbine control strategies, control parameter (KP–KI) combinations, wave heights and parked modes on the rotor aerodynamic responses of the FOWT system have been clarified. The extreme typhoon event can result in considerably large extreme responses of the rotor thrust and the generated power due to the possible blade pitch angle error phenomenon. One active-parked strategy has been proposed for reducing the maximum aerodynamic responses of the FOWT system during extreme typhoon events.

By tracing the 13C NMR resonances for carbonyls and enols, four new oxidized phomaligol derivatives, phomaligols F–I (1–4), along with seven known compounds (5–11) were isolated from the culture of the fungus Aspergillus flavus BB1 isolated from the marine shellfish Meretrix meretrix collected on Hailing Island, Yangjiang, China. The chemical structures and the absolute configurations of the new compounds were elucidated by MS, NMR, ECD, optical rotation, and 13C NMR calculations. Compounds 1 and 2 represent the first examples of phomaligol derivatives that contain an unusual bicyclic skeleton. All isolated compounds were tested for their cytotoxic activity. Among them, sporogen-AO 1 (8) showed potent inhibitory activity against the cancer cell lines A549, H1299, SK-BR-3, and HCT116 with IC50 values of 0.13, 0.78, 1.19, and 1.32 μM, respectively. Phomaligol G (2) displayed cytotoxic activity against the A549 and H1299 cell lines with IC50 values of 46.86 and 51.87 μM respectively. Additionally, phomaligol H (3) demonstrated cytotoxic activity against the A549 cell line with an IC50 value of 65.53 μM. Mechanistic studies of compound 8 showed that it induced apoptosis of HCT116 cells in a dose-dependent manner.

Precursor messenger RNA (pre-mRNA) splicing is critical for cell growth and development, and errors in RNA splicing frequently cause cellular dysfunction, abnormal gene expression, and a variety of human diseases. However, there is currently a lack of reliable systems to noninvasively monitor the mRNA splicing efficiency in cells and animals. Here, we described the design of a genetically engineered ratiometric dual luciferase reporter to continuously quantify the changes in mRNA splice variants in vivo. This reporter system is encoded within a single polypeptide but on separate exons, thus generating two distinct luciferase signals derived from spliced and unspliced mRNAs. With this reporter, the two kinds of luciferase in the same individual can minimize the influence of indirect factors on splicing, and the ratio of these two luciferase intensities represents the dynamic splicing efficiency of pre-mRNA. Our study offers a convenient and robust tool for the screening and identification of small molecules or trans-acting factors that affect the efficiency of specific splicing reactions.

The phase transition behaviors from the tetragonal form II to the trigonal form I of polybutene-1 ionomers with various ion contents and branch lengths were studied by means of differential scanning calorimetry. In the ionomers studied, ionic functional groups were located at the end of the branches incorporated, so ion content was varied with the incorporation ratio and, branch length was tuned by the distinct co-monomers of 6-iodo-1-hexene and 18-iodo-1-octadecene. The results show that although the branches introduced retard the II-I phase transition in reference copolymers, after introduction of ions, the ionomers exhibit the largely accelerated kinetics of the solid II-I phase transition. Interestingly, it was found that the phase transition exhibits a non-monotonic dependence on the ion content and for the ionomers with 4-carbon branches, the optimal ion content to obtain the maximum transition degree is around 2.6 mol%. This is probably due to the cooperative effects of the formation of intercrystalline links by the ion aggregates in ionomers, 1) the enhanced transfer of internal stress for nucleation and 2) the restricted chain mobility for adjusting segmental packing. Furthermore, the II-I phase transition can be further accelerated by increasing the 4-carbon branch to the 16-carbon branch via copolymerizing 18-iodo-1-octadecene as the comonomers. These results provide the helpful guide to the molecular design of polybutene-1 ionomer materials.

Novel low dielectric constant (low-k) polycarbosilanes with tunable performance are reported in the present work. These well-defined linear-cyclopolycarbosilanes were prepared via the copolymerization of 1,5-hexadiene (1,5-HD) with 3,3-dimethyl-3-sila-1,5-hexadiene (DMSHD) using dimethyl(pyridylamido) hafnium/[Ph3C][B(C6F5)4]/AliBu3 catalytic system. They exhibited excellent dielectric properties and the dielectric constant of the film samples was all lower than 2.5. The dielectric constant decreased gradually with the increase of DMSHD content, even approaching to 1.8 for the poly(DMSHD). In addition, the thermal, surface and mechanical properties of the copolymers were improved significantly after introducing C-Si bonds and can be exquisitely modulated by tuning the incorporation of the DMSHD units. Hydrophobic polymer films with high thermal stability could be prepared by solution casting or spin-on method. It was found that there were no porous and cavity in the poly(DMSHD) film, the intrinsic low dielectric constant could be attributed to its unique structure.

This paper concerns the interaction of focused waves with uniform current and a submerged horizontal plate in the context of the two-dimensional nonlinear potential theory. A fully nonlinear NWT (numerical wave tank) based on a time domain HOBEM (higher-order boundary element method) is applied to the numerical solutions. In the model, the Goda's method is modified to discriminate incident and reflected waves, whereas the acceleration potential approach is introduced to determine the hydrodynamic forces on the structure. The corresponding experiments are also conducted in a two-dimensional glass-walled wave tank at Jiangsu University of Science and technology. The developed model is verified with published numerical results and validated with experimental test. Through a systematic parametric study, it is found that the maximum reflection or minimum transmission for different currents occur at the same plate width because of the compensating Doppler effects of current. The spectral analysis reveals that the energy dissipation occurs primarily in the fundamental waves when focused waves propagating over the plate. The current has a stronger influence on the wave forces than on wave surface elevation. Furthermore, the 'secondary loading cycle' phenomenon is also observed in the time series of the wave forces for a following current.

Streptococcus suis serotype 2 (SS2) is a zoonotic pathogen causing meningitis in humans and pigs. However, information on the comparative protein expression of the blood-brain barrier (BBB) following SS2 infection is limited. Deletion of the serine/threonine kinase (stk) gene can decrease the ability of SS2 to invade the BBB. In the present study, bEnd.3 cells were used as the BBB model, and a SILAC comparative quantitative proteomic study of bEnd.3 cells infected with the SS2 ZY05719 or Δstk strain was performed to determine the differences between these strains infections. Compared with ZY05719-infected cells, 241 proteins were highly upregulated, and 81 were significantly downregulated in Δstk-infected cells. The obtained data revealed major changes in the proteins involved in RNA process, host cytoskeleton, tight junction disruption and immune response. Some differentially expressed proteins were screened by quantitative real-time PCR to examine their regulation at the transcriptional level, and western blot analysis was used to validate the changes of some selected proteins at the translational level. The results obtained in this study may be useful to understand the host response to SS2 infection and provide crucial clues to decipher how STK expression in SS2 helps the bacteria penetrate the BBB. SIGNIFICANCE: A SILAC comparative quantitative proteomic assay was performed in bEnd.3 cells infected with the SS2 ZY05719 or Δstk strain. 241 upregulated and 81 downregulated differentially expressed proteins (DEPs) were identified. DEPs are involved in RNA process, host cytoskeleton, tight junction disruption and immune response. Some DEPs were examined by qPCR and western blot assays, which were similar to those of their corresponding proteins in the quantitative proteomics analysis.