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Regarding development of the dedicated slag for electroslag remelting, crystallization characteristics of the slag exert a strong influence on the initial solidification of liquid metal in mold and surface quality of as-cast ingot. The crystallization behavior of CaF2–CaO–Al2O3-based slag with varying SiO2and B2O3contents and their correlation with the slag structure were investigated. Increasing SiO2(0.24–8.95 mass%) and B2O3(0–3.20 mass%) contents lowers the crystallization temperature and suppresses the crystallization of the slag melts, as well as decreases the sizes of the crystalline phases. The crystalline phases precipitated during continuous cooling of the slag melts are faceted 11CaO·7Al2O3·CaF2, faceted or spherical CaF2, and non-faceted MgO·Al2O3(or MgO) in sequence irrespective of the SiO2and B2O3contents of the slag. The polymerization degree of slag melts increases with increasing either SiO2or B2O3contents. The crystallization of the slag melts is increasingly retarded with increasing the SiO2and B2O3contents of the slag caused by increased component diffusion resistance originating from increased polymerization degree of the slag melts.

In this work, we introduce a synthesis method for a nanofiber membrane made of polyacrylonitrile and verify its filtration ability with micron-size particles. The polyacrylonitrile nanofiber membrane was produced by electro-spun technique with a thickness less than 0.2 mm. The filtration experimental result from micron-size particle penetration proved that after 60-min deposition, the polyacrylonitrile nanofiber membrane successfully filtrated ~99% micron-size particles in solution. We found that uniform morphology, consistent nanofiber diameter without disordered beads will lead to a better filtration performance. This finding will provide a low-cost, environmental-friendly and straightforward filtration approach for future PM2.5 elimination in an aqueous and harsh environment.

The novel reco mbinant euka ryotic VRPIL4/ 6 p lasmid, the secretory VR1020 vector containing fused pig IL-6 and IL-4 genes, was encapsulated with chitosan nanoparticles (CNP) prepared by use of ionotropic gelat ion method and then used to inoculate intramuscularly forty 14-day-old piglets using 0.5, 1.0 or 1.5mg/per anima l, which were simu ltaneously injected with inactivated Mycoplasma hyopneumoniaevaccine and challenged on 10 weeks post vaccination, which were designated as group A1, A2 and A3. Blood was collected every two weeks fro m the piglets after vaccination to detect the changes in immunoglobulin, specific antibod y, IL-2, IL-4, IL-6, IFN-γ and immune ce lls. Co mpared to the control piglets with VR1020-CNP, the concentration of Ig G, IgA and IgM, specific antibody, interleukins and IFN-γ significantly increased in the sera of the groups treated with the fusion genes fro m 14 to 70 days after vaccination (P<0.05); furthermore, the nu mber of TH, TCand CD3+T ce lls was raised significantly in the blood of the treated piglets (P<0.05). Meanwhile, the ly mphocytes and monocytes also significantly rose in the treated groups (P<0.05). The hu mora l and ce llu lar immune inde xes of the A3 group increased to different e xtents in co mparison with those of A 1 and A 2 group fro m 14 to 56 days post inoculation (P>0.05 or P<0.05). The protection against challenge with viru lent M hyo and growth performance of the treated pigs is markedly better than those of the control anima l (P<0.05). These results indicated that VRPIL4/6 entrapped with CNP can enhance the humora l and cellu lar immunity of pigs to Mycoplasma hyopneumoniaevaccine, and elevate the immunoprotection level of treated anima l, wh ich could facilitate the development of effective immunoadjuvant against Mycoplasma hyopneumoniaeof pig.