Plane charge explosion technique (PCET) is one of the major techniques frequently used in large-scale blast-resistant structure tests. An FEM model was established, which can simulate the process of air releasing from...Plane charge explosion technique (PCET) is one of the major techniques frequently used in large-scale blast-resistant structure tests. An FEM model was established, which can simulate the process of air releasing from the blast cavity. The effects of the charge density, the interval of the charge strip, the distance of the charges from the structure, and the mass of backfill soil on the overpressures applied on the tested structures were analyzed by the FEM model. The quantitative relationships between the peak value and the duration of the overpressure and the above-mentioned affecting parameters were established. Agreement between numerical results and the test data was obtained.展开更多
Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to d...Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to design electrostatic charged podwer spraying system. The chargingeffectiveness of ring and pin electrode is experimentally investigated and compared each other. Theperformance of ring electrode is better than that of pin electrode.展开更多
Extracts of elephant grass （Penniseturn purpureum） blended with some intensifier halides like ammonium chloride （AMC） and potassium iodide （PTI） were investigated as corrosion inhibitor for mild steel. The corro...Extracts of elephant grass （Penniseturn purpureum） blended with some intensifier halides like ammonium chloride （AMC） and potassium iodide （PTI） were investigated as corrosion inhibitor for mild steel. The corrosion process was monitored in 3.5% HCI by mass loss and electrochemical techniques at 30, 40, 50, 60 and 90 ℃. Addition of AMC and PTI increased the inhibition efficiency with the highest inhibition efficiency obtained with PTI blend- ed extract. The blends behaved as mixed type inhibitors and were spontaneously adsorbed on mild steel surface in exothermic nature. Synergistic parameters of the intensifier ions revealed cooperative effect. Kinetic data treatment indicated increase in energy barrier by intensifier ions. The results demonstrate that elephant grass extract blended with halide ions can act as alternative ecofriendly inhibitor for mild steel at elevated temperatures.展开更多
Two kinds of W/Cu double-layer shaped charge liner（SCL） were prepared by chemical vapor deposition（CVD） combined with electroforming technique： A SCL with W inner layer and Cu outer layer, B SCL with Cu inner lay...Two kinds of W/Cu double-layer shaped charge liner（SCL） were prepared by chemical vapor deposition（CVD） combined with electroforming technique： A SCL with W inner layer and Cu outer layer, B SCL with Cu inner layer and W outer layer. The penetration properties of A and B SCLs were researched. The results show that the two SCLs can form continuous jet and the tip velocities of A and B jets are 7.4 and 6.3 km s^（-1）, respectively. The kinetic energy density（5.3 9 1011 J m-3） of A jet tip increases by 194.4 %compared with that（1.8 9 1011 J m-3） of B jet tip. B jet,however, exhibits deeper penetration depth at the same experimental conditions. The chemical component and microstructure of the area nearby the ballistic perforation were researched. Component analysis shows that both the jets are formed only from inner layer metal. Microstructure analysis shows that martensite and intermetallic form around ballistic perforation penetrated by A SCL due to the intensive interaction between W jet and steel target. The two kinds of newly formed ultrahard phases also hinder the jet from penetrating target further. As a result of relatively alleviative interaction between Cu jet and target, only solid solution rather than ultrahard phases forms around ballistic perforation penetrated by B SCL.展开更多
文摘Plane charge explosion technique (PCET) is one of the major techniques frequently used in large-scale blast-resistant structure tests. An FEM model was established, which can simulate the process of air releasing from the blast cavity. The effects of the charge density, the interval of the charge strip, the distance of the charges from the structure, and the mass of backfill soil on the overpressures applied on the tested structures were analyzed by the FEM model. The quantitative relationships between the peak value and the duration of the overpressure and the above-mentioned affecting parameters were established. Agreement between numerical results and the test data was obtained.
文摘Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to design electrostatic charged podwer spraying system. The chargingeffectiveness of ring and pin electrode is experimentally investigated and compared each other. Theperformance of ring electrode is better than that of pin electrode.
基金financial support provided by World Bank Robert S.Mc Namara Fellowship Program 2015 to carry out this research abroad
文摘Extracts of elephant grass （Penniseturn purpureum） blended with some intensifier halides like ammonium chloride （AMC） and potassium iodide （PTI） were investigated as corrosion inhibitor for mild steel. The corrosion process was monitored in 3.5% HCI by mass loss and electrochemical techniques at 30, 40, 50, 60 and 90 ℃. Addition of AMC and PTI increased the inhibition efficiency with the highest inhibition efficiency obtained with PTI blend- ed extract. The blends behaved as mixed type inhibitors and were spontaneously adsorbed on mild steel surface in exothermic nature. Synergistic parameters of the intensifier ions revealed cooperative effect. Kinetic data treatment indicated increase in energy barrier by intensifier ions. The results demonstrate that elephant grass extract blended with halide ions can act as alternative ecofriendly inhibitor for mild steel at elevated temperatures.
基金financially supported by the National Natural Science Foundation of China(No.51201013)
文摘Two kinds of W/Cu double-layer shaped charge liner（SCL） were prepared by chemical vapor deposition（CVD） combined with electroforming technique： A SCL with W inner layer and Cu outer layer, B SCL with Cu inner layer and W outer layer. The penetration properties of A and B SCLs were researched. The results show that the two SCLs can form continuous jet and the tip velocities of A and B jets are 7.4 and 6.3 km s^（-1）, respectively. The kinetic energy density（5.3 9 1011 J m-3） of A jet tip increases by 194.4 %compared with that（1.8 9 1011 J m-3） of B jet tip. B jet,however, exhibits deeper penetration depth at the same experimental conditions. The chemical component and microstructure of the area nearby the ballistic perforation were researched. Component analysis shows that both the jets are formed only from inner layer metal. Microstructure analysis shows that martensite and intermetallic form around ballistic perforation penetrated by A SCL due to the intensive interaction between W jet and steel target. The two kinds of newly formed ultrahard phases also hinder the jet from penetrating target further. As a result of relatively alleviative interaction between Cu jet and target, only solid solution rather than ultrahard phases forms around ballistic perforation penetrated by B SCL.
