The boundary integral method（BIM） is used to simulate the 3-D gas bubble, generated within the two bubble pulsation periods in proximity to a free surface in an inviscid, incompressible and irrotational flow. The pr...The boundary integral method（BIM） is used to simulate the 3-D gas bubble, generated within the two bubble pulsation periods in proximity to a free surface in an inviscid, incompressible and irrotational flow. The present method is well validated by comparing the calculated shapes of the bubble and the free surface with both the experimental results and the numerical ones obtained by the Axisymmetric BIM code. The expansion, the collapse of the gas bubble and the further evolution of the rebounding non-spherical bubble are simulated. The various variation patterns of the free surface spike and the bubble centroid for different standoff distances, the buoyancy parameters and the strength parameters are obtained to reveal the nonlinear interaction between the bubble and the free surface. The amplitude of the second maximum bubble volume and the four typical patterns of the bubble jet and the free surface spike are examined in the context of the standoff distance. The large buoyancy is used to elevate the spray dome rather than the free surface spike.展开更多
Catalytic bubble-free hydrogenation reduction of azo dye by porous membranes loaded with palladium （Pd） nanoparticles was studied for the first time. The effects of Pd loading, dye concentration and reuse repetition...Catalytic bubble-free hydrogenation reduction of azo dye by porous membranes loaded with palladium （Pd） nanoparticles was studied for the first time. The effects of Pd loading, dye concentration and reuse repetitions of membranes were investigated. In reduction, the dye concentration decreased whereas the pH rose gradually. An optimal Pd loading was found. The catalytic membranes were able to be reused more than 3 times.展开更多
A two-step bonding process using a novel hybrid electrode is presented.The effects of different electrodes on bonding time,bond strength and the bonded interface are analyzed.The anodic bonding is studied using a dome...A two-step bonding process using a novel hybrid electrode is presented.The effects of different electrodes on bonding time,bond strength and the bonded interface are analyzed.The anodic bonding is studied using a domestic bonding system,which carries out a detailed analysis of the integrity of the bonded interface and the bond strength measurement.With the aid of the hybrid electrode,a bubble-free anodic bonding process could be accomplished within 15-20 min,with a shear strength in excess of 10 MPa.These results show that the proposed method has a high degree of application value,including in most wafer-level MEMS packaging.展开更多
An amorphous Ge（a-Ge） intermediate layer is introduced into the Si bonded interface to lower the annealing temperature and achieve good electrical characteristics. The interface and electrical characteristics of nSi...An amorphous Ge（a-Ge） intermediate layer is introduced into the Si bonded interface to lower the annealing temperature and achieve good electrical characteristics. The interface and electrical characteristics of nSi/n-Si and p-Si/n-Si junctions manufactured by low-temperature wafer bonding based on a thin amorphous Ge are investigated. It is found that the bubble density tremendously decreases when the a-Ge film is not immersed in DI water. This is due to the decrease of the –OH groups. In addition, when the samples are annealed at 400 °C for20 h, the bubbles totally disappear. This can be explained by the appearance of the polycrystalline Ge（absorption of H;） at the bonded interface. The junction resistance of the n-Si/n-Si bonded wafers decreases with the increase of the annealing temperature. This is consistent with the recrystallization of the a-Ge when high-temperature annealing is conducted. The carrier transport of the Si-based PN junction annealed at 350 °C is consistent with the trap-assisted tunneling model and that annealed at 400 °C is related to the carrier recombination model.展开更多
基金supported by the National Natural Science Foun-dation of China(Grant Nos.51221961,51279030)the National Key Basic Research Development Program of China(973 Pro-gram,Grant Nos.2013CB036101,2010CB832704)the Fundamental Research Funds for the Central Universities(Grant No.L2012016)
文摘The boundary integral method（BIM） is used to simulate the 3-D gas bubble, generated within the two bubble pulsation periods in proximity to a free surface in an inviscid, incompressible and irrotational flow. The present method is well validated by comparing the calculated shapes of the bubble and the free surface with both the experimental results and the numerical ones obtained by the Axisymmetric BIM code. The expansion, the collapse of the gas bubble and the further evolution of the rebounding non-spherical bubble are simulated. The various variation patterns of the free surface spike and the bubble centroid for different standoff distances, the buoyancy parameters and the strength parameters are obtained to reveal the nonlinear interaction between the bubble and the free surface. The amplitude of the second maximum bubble volume and the four typical patterns of the bubble jet and the free surface spike are examined in the context of the standoff distance. The large buoyancy is used to elevate the spray dome rather than the free surface spike.
基金supported by the National Natural Science Foundation of China (No. 20676016, 21076024)the State Key Laboratory of Chemical Resource Engineering
文摘Catalytic bubble-free hydrogenation reduction of azo dye by porous membranes loaded with palladium （Pd） nanoparticles was studied for the first time. The effects of Pd loading, dye concentration and reuse repetitions of membranes were investigated. In reduction, the dye concentration decreased whereas the pH rose gradually. An optimal Pd loading was found. The catalytic membranes were able to be reused more than 3 times.
基金supported by the Development Project of the Scientific Equipment of the Chinese Academy of Sciences(No.YZ200940)
文摘A two-step bonding process using a novel hybrid electrode is presented.The effects of different electrodes on bonding time,bond strength and the bonded interface are analyzed.The anodic bonding is studied using a domestic bonding system,which carries out a detailed analysis of the integrity of the bonded interface and the bond strength measurement.With the aid of the hybrid electrode,a bubble-free anodic bonding process could be accomplished within 15-20 min,with a shear strength in excess of 10 MPa.These results show that the proposed method has a high degree of application value,including in most wafer-level MEMS packaging.
基金Project supported by the National Natural Science Foundation of China(Nos.61534005,61474081)
文摘An amorphous Ge（a-Ge） intermediate layer is introduced into the Si bonded interface to lower the annealing temperature and achieve good electrical characteristics. The interface and electrical characteristics of nSi/n-Si and p-Si/n-Si junctions manufactured by low-temperature wafer bonding based on a thin amorphous Ge are investigated. It is found that the bubble density tremendously decreases when the a-Ge film is not immersed in DI water. This is due to the decrease of the –OH groups. In addition, when the samples are annealed at 400 °C for20 h, the bubbles totally disappear. This can be explained by the appearance of the polycrystalline Ge（absorption of H;） at the bonded interface. The junction resistance of the n-Si/n-Si bonded wafers decreases with the increase of the annealing temperature. This is consistent with the recrystallization of the a-Ge when high-temperature annealing is conducted. The carrier transport of the Si-based PN junction annealed at 350 °C is consistent with the trap-assisted tunneling model and that annealed at 400 °C is related to the carrier recombination model.
