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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.

On the basis of the simplest and deterministic chemostat model, we introduce impulsive input, nutrient recycling, and distributed time-delay into the model in this paper. By using comparison theorem, Floquet theory, and small amplitude skills in the impulsive differential equation, it proves that if the period of impulsive input is too long and the parameter α of the kernel function in the delay is too small, then there exists a microorganism-eradication periodic solution that is globally asymptotically stable, and the cultivation of the microorganism fails. On the contrary, if we choose suitable impulsive strategy, such as increasing the concentration of the substrate or enhance the proportion of the concentration of the impulsive input of the substrate at periodic time to that for the microbial growth, then the system could be controlled to be permanent, and the cultivation of the microorganism will be successful. Copyright © 2013 John Wiley & Sons, Ltd.

In this paper, some asymptotic properties of a stochastic predator-prey model with Crowley-Martin functional response are studied. First, we obtain the global existence of a positive unique solution of the model. Then, the stochastically bounded of the positive solution to the stochastic model is derived. Besides, some conditions for species to be stochastically permanent are given. We also show that the species will become extinct with probability one if the noise is sufficiently large. In the end, some simulation figures are carried out to support the analytical findings.

In this article, spinel–type NiCr2O4 Nanocrystalline were prepared by the citrate method. After doping it into P25 (degussa, TiO2), NiCr2O4/TiO2 thin film photoanode were prepared by screen printing process on the surface of Fluorine Tin Oxide (FTO) Glass. And then they were assembled into Dye sensitized TiO2 Nanocrystalline solar cells (DSSC). The as–prepared NiCr2O4 powders were characterized by differential thermal analysis/thermo gravimetry (DTA/TG), X–ray diffraction (XRD) and ultraviolet visible (Uv–Vis) diffuse spectra. The properties of the solar cells were investigated by Solar Simular and Keithley Sourcemeter, respectively. The results showed that the grain size of the NiCr2O4 particles obtained at optimum synthesis temperature (1000 °C) was about 40.23 nm and the band gap was 1.8ev. The cell properties increased when the doping amount of NiCr2O4 was 1wt%. The open–circuit voltage (Voc) of Dye Sensitized TiO2 Nanocrystalline Solar Cell was from 0.71V up to 0.73V, The short–circuit photocurrent (Jsc) of DSSC increased from 5.21mA·cm-2 to 6.95mA·cm-2. The photoelectric conversion efficiency (η) was from 2.40% up to 3.14%, which was 30.8% higher than the pure TiO2 thin film photoanode.

Spinel MCr2O4(M = Cu, Ni) nanopowders were synthesized by co-precipitation technique from alcohol-aqueous system and the performance of MCr2O4/TiO2 composite film electrodes was studied. The synthesized MCr2O4 nanopowders were characterized by X-ray diffraction (XRD) and UV-vis diffuse reflectance spectrum (UV-vis). The MCr2O4 nanopowders were doped into nanocrystalline semiconductor oxide film electrode of DSSCs and the influence of doping content was investigated. Compared with the pure TiO2 film electrode, the absorbance of different MCr2O4/TiO2 composite film electrode increased significantly. Furthermore, the light respondence of CuCr2O4/TiO2 composite electrode was better than NiCr2O4/TiO2 composite electrode. When the content of CuCr2O4 2%, the photoelectric conversion efficiency increased by 54%, and doping 1% NiCr2O4 nanopowders, the photoelectric conversion efficiency was improved 30%.

Liquid electrolyte for dye-sensitized solar cells (DSSCs) was prepared by using the mixture of sulfolane and 3-methoxypropionitrile as a solvent, 4-tert-butylpyridine as an additive. The influences of sulfolane on electrolyte conductivity, photoelectric performances and the DSSCs stability were investigated. The results indicated that when the ratio of 3-methoxypropionitrile to sulfolane achieves 3:2, the cell showed the optimal photoelectric properties and stability, and the short-circuit current and photoelectric conversion efficiency achieved 7.58mA/cm2 and 2.79%, respectively.

In this paper, the internal air pressure and bottom water pressure of the buckets, the acceleration of swaying, surging and heaving of platform were determined by the sensors fixed on the platform, as a naval bucket foundation platform for example. The motion rules of heave and sway of bucket foundations are studied with different drafts. The results of this test showed that the added mass coefficient of heave, roll and pitch are declined with the increase of the draft; the natural frequency of heave is constant with different drafts but the roll frequency and pitch frequency are consistent with the changes of the draft; the frequency of heave is larger than that of roll and pitch but the added mass coefficient of heave is lesser than that of roll and pitch.

In this paper, a viral infection SVI model with lytic immune response is studied. What's more, in order to control the quantity of the virus population, periodic medication strategy is introduced to the classical SVI model. By some mathematical analysis techniques, an important threshold

Rosiglitazone (ROSI), thiazolidione peroxisome proliferator-activated receptor-gamma (PPAR-gamma) activator, reduces insulin resistance in patients with type 2 diabetes (T2DM). It also improves vascular reactivity in T2DM patients and some animal models by unclear mechanisms. In order to investigate the effect of ROSI on aortic systolic and diastolic function of insulin resistant-hypertensive rats (IRHR) and the underlying mechanism, male Sprague-Dawley (SD) rats were fed with high fructose (HF) for 8 weeks to induce IRHR model. To verify IRHR model, systolic blood pressure (SBP), fasting blood sugar (FBS), fasting serum insulin (FSI) were measured respectively in each group, and insulin sensitive index (ISI) was also calculated. Subsequently, the vascular function test was performed. The thoracic aortic ring of SD rats was mounted on a bath system. The effect of rosiglitazone on the contraction elicited by L-phenylephrine (PE) and potassium chloride (KCl) and the relaxation induced by acetylcholine (ACh) and sodium nitroprusside (SNP) were measured. To explore the mechanism, nitric oxide synthase (NOS) inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) was used and serum nitric oxide (NO) was measured. The results obtained were as follows: (1) Rosiglitazone reduced the level of SBP, serum insulin and improved insulin resistance in IRHRs. (2) The contractive responses of thoracic aortic rings to PE and KCl were enhanced and the relaxation response to ACh was depressed significantly in the HF group, and the effect was reversed by ROSI. (3) After pretreatment with L-NAME, the relaxation response to ACh was further impaired in the HF group, this effect was partly reversed by ROSI. (4) Sodium nitroprusside (SNP)-induced vasodilator responses did not differ significantly among the groups. (5) Aortic systolic and diastolic function of the control group was not affected markedly by ROSI. (6) Compared with the control group, serum nitric oxide was significantly reduced in the HF group, but after rosiglitazone treatment it was remarkably increased. These findings suggest that ROSI can improve aortic diastolic function of insulin resistant-hypertensive rats, the mechanism of this effect might be associated with an increase in nitric oxide mediated partly by NOS pathway, a decrease in the level of blood pressure, serum insulin and the improvement of insulin resistance.