Abstract:The use of a cylindrical high-explosive charge with a wave-shaper is an efficient way to obtain an ultra-high pressure and a convergent detonation wave. An analysis of flow fields corresponding to the regular and Mach reflection of detonation waves in a cylindrical high-explosive charge with a wave-shaper is presented in this paper. The pressure, flow velocity and triple point growth angle of the Mach stem were calculated. The Mach stem height was also determined by using the modified Whitham method. The results show that the Mach stem height rises from zero at the critical angle of Mach reflection and changes to the Chapman-Jouguet detonation state with the propagation of the detonation waves. Shock indentation experiments were conducted, in which a wave-shaper was used in a cylindrical high-explosive charge to form Mach reflection detonation waves. The results showed that the discrepancy between the experimental results and the theoretical calculations was less than 15%, which proves the validity of the proposed theoretical model.
The objective of this paper was to investigate the effect of dextran gel on preparation of nano-liposomes loaded with ginkgolide. During preparation, Sephadex G75, G50 and G25 were added in the aqueous phase respectively. From the experiment, nano-liposomes prepared by dextran gels were found spherical and smooth. The result indicated that aperture of dextran gels were narrower, particle size of nano-liposomes was smaller (207.13 ~ 89.16 nm) and zeta potential was greater (-36.2 ~ -29.5 mV) in more negative. The study also revealed that differences of the entrapment efficiency and drug loading among the three types of nano-liposomes were not significant. In vitro drug release test demonstrated that nano-liposomes had a better controlled release. To conclude, by using dextran gel in the preparation of nano-liposome loaded with ginkgolide, the particle size could be effectively controlled and the drug stability could be improved.
Smelting slag, a solid industrial waste, has become a major environmental pollution in Baoshan, Shanghai. This thesis makes a detailed analysis of categories, components and functions of smeling slag and puts forward approaches to treatment of steel slag waste in Baoshan District against situations in Bao Steel and its affiliates in hopes of contributing to the improvement of Shanghai’s environment.
NaA / MCM-48 micro-mesoporous molecular sieve was prepared at 100°C for 72 h by hydrothermal synthesis method, where chemicals with a equivalent ratio of n (SiO2)∶n (CTAB)∶n (H2O)∶n ( NaOH) is 1∶0.45∶60∶0.48 were added to NaA microporous molecular sieve prepared hydrothermally at 100°C for 5 h from a composite solution with a equivalent ratio of Na2O∶SiO2∶Al2O3∶H2O is 3∶2∶1∶200. The adsorption of the NaA / MCM-48 micro-mesoporous molecular sieve to cationic red X-5GN simulated dye existing in the waste water showed that, in 50 mL of 20 mg/L cationic red X-5GN solution, under the optimal conditions of a dosage of NaA/MCM-48 micro-mesoporous composite molecular sieve of 1.8g/L, a pH of 7 and an oscillation time of 30min, the decoloration rate of spent solution was above 82.5%. The XRD, SEM and TEM processes were adopted for its characterization to display the possible reasons.
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