目的研究HAPw/nmZnO-nmCaO对金黄色葡萄球菌、铜绿假单胞菌的体外抗菌性能。方法配制D_(595nm)=0.1的金黄色葡萄球菌、铜绿假单胞菌悬液。用灭菌纯水配制浓度为1 g/L的HAPw、Bio-oss、HAPw/nmZnO-nmCaO材料悬浊液。A组:5 m L培养基+1 m ...目的研究HAPw/nmZnO-nmCaO对金黄色葡萄球菌、铜绿假单胞菌的体外抗菌性能。方法配制D_(595nm)=0.1的金黄色葡萄球菌、铜绿假单胞菌悬液。用灭菌纯水配制浓度为1 g/L的HAPw、Bio-oss、HAPw/nmZnO-nmCaO材料悬浊液。A组:5 m L培养基+1 m L HAPw/nmZnO-nmCaO+200μL菌悬液; B组:5 m L培养基+1 m L HAPw+200μL菌悬液; C组:5 m L培养基+1 mL Bio-oss+200μL菌悬液; D空白组:5 m L培养基+1 m L灭菌纯水+200μL菌悬液。各组37℃恒温培养20 h,取样进行浓度梯度稀释。稀释后的菌液取100μL涂布于琼脂平板,37℃恒温培养20 h行平板菌落计数。结果金黄色葡萄球菌和铜绿假单胞菌HAPw/nmZnO-nmCaO组的菌落数量少于HAPw、Bio-oss、空白对照组(P<0.001),HAPw、Bio-oss、空白对照组3组之间无差异(P>0.05)。结论 HAPw/nmZnO-nmCaO对金黄色葡萄球菌、铜绿假单胞菌的生长均有抑制作用,对金黄色葡萄球菌的抑制作用强于铜绿假单胞菌。展开更多
The metallographic structure of LM-29 aluminum-silicon alloy modified by electric pulse treatment has been investigated and compared with those untreated.The solidification structure of LM-29 alloy has been analyzed b...The metallographic structure of LM-29 aluminum-silicon alloy modified by electric pulse treatment has been investigated and compared with those untreated.The solidification structure of LM-29 alloy has been analyzed by means of M1AP3 Quantimet image processing and analysis system,and then the solidification process has been analyzed by means of differential scanning calorimetry(DSC).The results indicate that the primary silicon phase was refined remarkably by electric pulse while the tensile strength and elongation properties increased accordingly.Electric pulse treatment can also increase the binding power between silicon clusters and alloy melt matrix,as a result,the precipitation of primary silicon phase is suppressed to meet the demand of supercooling degree for nucleating,correspondingly.The electric pulse modification has great influence on the size of silicon atomic cluster as well as its distribution in the melt,subsequently,leads to the refinement of solidification structure.展开更多
Based on the empirical electron theory of solids and molecules (EET), the phase valence electron structure parameters of Al-22%Si alloy are calculated, and the sensitivity of the bond network of Al-Si alloy melt to te...Based on the empirical electron theory of solids and molecules (EET), the phase valence electron structure parameters of Al-22%Si alloy are calculated, and the sensitivity of the bond network of Al-Si alloy melt to temperature (energy) and the effect of the sensitivity on the morphology are studied. The results show that the Si-Si clusters with larger nA in the slightly superheated Al-Si alloy melt supply the nucleation core to the primary silicon phase in the hypereutectic Al-22%Si alloy, and strongly generate the drag-like effect for the Al-Si clusters around them; that the variation of temperature significantly affects the stability of bonds of the core so that the solidified structure is changed; that the electric pulse applied to the alloy melt can irrecoverably alter the stability of Si-Si clusters, then the modifica- tion of the solidified structure morphology of alloys is generated; that the higher the energy of the electric pulse, the less stable the Si-Si clusters, and the more significant the electric pulse modification.展开更多
Based on the electric dipole theory, the coupled field distribution of pulse electric field (PEF) with electric dipole field around the cluster in superheated molten alloy is simulated under the effect of PEF. For the...Based on the electric dipole theory, the coupled field distribution of pulse electric field (PEF) with electric dipole field around the cluster in superheated molten alloy is simulated under the effect of PEF. For the difference of electro-migration, the atom of solute and solution will accumulate around the cluster, and then the smaller cluster may reorganize and grow up under the action of the coupled field. We also apply the electrostatic induction theory to analyze the bearing behavior of the half side of the cluster. The bigger the cluster is, the stronger the electrostatic force is, therefore, the bigger cluster's stability is weak apparently. The study indi- cates that the cluster in the superheated molten has the homogeneous tendency under the effect of PEF.展开更多
文摘目的研究HAPw/nmZnO-nmCaO对金黄色葡萄球菌、铜绿假单胞菌的体外抗菌性能。方法配制D_(595nm)=0.1的金黄色葡萄球菌、铜绿假单胞菌悬液。用灭菌纯水配制浓度为1 g/L的HAPw、Bio-oss、HAPw/nmZnO-nmCaO材料悬浊液。A组:5 m L培养基+1 m L HAPw/nmZnO-nmCaO+200μL菌悬液; B组:5 m L培养基+1 m L HAPw+200μL菌悬液; C组:5 m L培养基+1 mL Bio-oss+200μL菌悬液; D空白组:5 m L培养基+1 m L灭菌纯水+200μL菌悬液。各组37℃恒温培养20 h,取样进行浓度梯度稀释。稀释后的菌液取100μL涂布于琼脂平板,37℃恒温培养20 h行平板菌落计数。结果金黄色葡萄球菌和铜绿假单胞菌HAPw/nmZnO-nmCaO组的菌落数量少于HAPw、Bio-oss、空白对照组(P<0.001),HAPw、Bio-oss、空白对照组3组之间无差异(P>0.05)。结论 HAPw/nmZnO-nmCaO对金黄色葡萄球菌、铜绿假单胞菌的生长均有抑制作用,对金黄色葡萄球菌的抑制作用强于铜绿假单胞菌。
基金supported by the National Natural Science Foundation of China (No. 50674054)the Doctorate Foundation of Science and Technology Department,Liaoning Province (20081097)
文摘The metallographic structure of LM-29 aluminum-silicon alloy modified by electric pulse treatment has been investigated and compared with those untreated.The solidification structure of LM-29 alloy has been analyzed by means of M1AP3 Quantimet image processing and analysis system,and then the solidification process has been analyzed by means of differential scanning calorimetry(DSC).The results indicate that the primary silicon phase was refined remarkably by electric pulse while the tensile strength and elongation properties increased accordingly.Electric pulse treatment can also increase the binding power between silicon clusters and alloy melt matrix,as a result,the precipitation of primary silicon phase is suppressed to meet the demand of supercooling degree for nucleating,correspondingly.The electric pulse modification has great influence on the size of silicon atomic cluster as well as its distribution in the melt,subsequently,leads to the refinement of solidification structure.
基金the National Natural Science Foundation of China (Grant No. 50674054) the College Key Laboratory Open Fund of Liaoning Province(Grant No. 200516203)
文摘Based on the empirical electron theory of solids and molecules (EET), the phase valence electron structure parameters of Al-22%Si alloy are calculated, and the sensitivity of the bond network of Al-Si alloy melt to temperature (energy) and the effect of the sensitivity on the morphology are studied. The results show that the Si-Si clusters with larger nA in the slightly superheated Al-Si alloy melt supply the nucleation core to the primary silicon phase in the hypereutectic Al-22%Si alloy, and strongly generate the drag-like effect for the Al-Si clusters around them; that the variation of temperature significantly affects the stability of bonds of the core so that the solidified structure is changed; that the electric pulse applied to the alloy melt can irrecoverably alter the stability of Si-Si clusters, then the modifica- tion of the solidified structure morphology of alloys is generated; that the higher the energy of the electric pulse, the less stable the Si-Si clusters, and the more significant the electric pulse modification.
基金Supported jointly by the National Natural Science Foundation of China (Grant No. 50674054)the College Key Laboratory Open Fund of Liaoning Province (Grant No. 200516203)
文摘Based on the electric dipole theory, the coupled field distribution of pulse electric field (PEF) with electric dipole field around the cluster in superheated molten alloy is simulated under the effect of PEF. For the difference of electro-migration, the atom of solute and solution will accumulate around the cluster, and then the smaller cluster may reorganize and grow up under the action of the coupled field. We also apply the electrostatic induction theory to analyze the bearing behavior of the half side of the cluster. The bigger the cluster is, the stronger the electrostatic force is, therefore, the bigger cluster's stability is weak apparently. The study indi- cates that the cluster in the superheated molten has the homogeneous tendency under the effect of PEF.
