In order to solve the drifting away of thermal fog droplets during thermal spraying and the incompatibility between fog droplet carrier and conventional com- mercial agro-chemicals, the fog droplet carrier, surfactant...In order to solve the drifting away of thermal fog droplets during thermal spraying and the incompatibility between fog droplet carrier and conventional com- mercial agro-chemicals, the fog droplet carrier, surfactant, condensation nucleus ma- terial and antifreeze, dispersant, thickener and defoamer were screened and assem- bled to develop a thermal fog sedimentation stabilizer in this study, thereby provid- ing technical support for application and promotion of thermal spraying technology in pest and disease control in crops.展开更多
The influence of processing parameters on the precision of parts fabricated by fused deposition modeling （FDM） technology is studied based on a series of performed experiments. Processing parameters of FDM in terms ...The influence of processing parameters on the precision of parts fabricated by fused deposition modeling （FDM） technology is studied based on a series of performed experiments. Processing parameters of FDM in terms of wire-width compensation, extrusion velocity, filing velocity, and layer thickness are chosen as the control fac- tors. Robust design analysis and multi-index fuzzy comprehensive assessment method are used to obtain the opti- mal parameters. Results show that the influencing degrees of these four factors on the precision of as-processed parts are different. The optimizations of individual parameters and their combined effects are of the same impor- tance for a high precision manufacturing.展开更多
Microstructure stability of in situ synthesized Ti2AlN/Ti-48Al-2Cr-2Nb composite during aging at 900 ℃ was investigated by XRD, OM and TEM, and the unreinforced Ti-48Al-2Cr-2Nb alloy was also examined for comparison....Microstructure stability of in situ synthesized Ti2AlN/Ti-48Al-2Cr-2Nb composite during aging at 900 ℃ was investigated by XRD, OM and TEM, and the unreinforced Ti-48Al-2Cr-2Nb alloy was also examined for comparison. The result showed that in the TiAl alloy,α2 lamellae thinned and were broken down, and became discontinuous with increasing aging time. The decomposition ofα2 lamella toγ which was characterized by parallel decomposition and breakdown ofα2 lamellae led to the degradation of the lamellar structure. While in the composite, lamellar structure remained relatively stable even after aging at 900 ℃ for 100 h. No breakdown ofα2 lamellae except parallel decomposition and precipitation of fine nitride particles was observed. The better microstructural stability of the composite was mainly attributed to the precipitation of Ti2AlN particles at theα2/γ interface which played an important role in retarding the coarsening of lamellar microstructure in the matrix of composite.展开更多
Ni-TiN nanocomposite films were produced from a Ni plating bath containing TiN nanoparticles by using dc electroplating method. The structure and surface morphology of Ni-TiN composite coatings were analyzed by atom f...Ni-TiN nanocomposite films were produced from a Ni plating bath containing TiN nanoparticles by using dc electroplating method. The structure and surface morphology of Ni-TiN composite coatings were analyzed by atom force microscope, X-ray diffraction, and trans- mission electron microscopy. Meanwhile, the anti-corrosion properties, hardness and ther- mostability of Ni-TiN nanocomposite films were also investigated and compared with the traditional polycrystalline Ni coatings. The results show that, compared with the traditional polycrystalline Ni film, Ni-TiN nanocomposite coatings display much better corrosion resistance, higher film hardness, and thermal stability. In addition, the hardness of Ni-TiN nanocomposite coatings decreases slightly with the increase of electroplating current density, which may be due to the synergism of hydrogen evolution and faster nucleation/growth rate of nickel crystallites.展开更多
To achieve a safe treatment of arsenic-containing acid wastewater,a new process was proposed,including arsenic removal via sulfide precipitation and hydrothermal mineralization stabilization.Under optimal conditions o...To achieve a safe treatment of arsenic-containing acid wastewater,a new process was proposed,including arsenic removal via sulfide precipitation and hydrothermal mineralization stabilization.Under optimal conditions of sulfide precipitation,99.65%of arsenic from wastewater was precipitated in the form of amorphous As2S3.The As leaching concentration of amorphous As2S3 in TCLP(toxicity characteristic leaching procedure)test was up to 212.97 mg/L,therefore,hydrothermal mineralization was adopted to improve the stability of amorphous As2S3.The results showed that the As leaching concentration of mineralized As2S3 was only 4.82 mg/L.Furthermore,the amorphous As2S3 could be transformed into crystallized As2S3(orpiment)in the presence of mineralizer Na2SO4.Simultaneously,the As leaching concentration of crystallized As2S3 was further reduced to 3.86 mg/L.Hydrothermal mineralization was an effective method for the stabilization of As2S3.Therefore,this process has a greater application in the treatment of arsenic-containing wastewater.展开更多
Seafloor elongated depressions are indicators of gas seepage or slope instability. Here we report a sequence of slopeparallel elongated depressions that link to headwalls of sediment slides on upper slope. The depress...Seafloor elongated depressions are indicators of gas seepage or slope instability. Here we report a sequence of slopeparallel elongated depressions that link to headwalls of sediment slides on upper slope. The depressions of about 250 m in width and several kilometers in length are areas of focused gas discharge indicated by bubble-release into the water column and methane enriched pore waters. Sparker seismic profiles running perpendicular and parallel to the coast, show gas migration pathways and trapped gas underneath these depressions with bright spots and seismic blanking. The data indicate that upward gas migration is the initial reason for fracturing sedimentary layers. In the top sediment where two young stages of landslides can be detected, the slopeparallel sediment weakening lengthens and deepens the surficial fractures, creating the elongated depressions in the seafloor supported by sediment erosion due to slope-parallel water currents.展开更多
基金Supported by Anhui Agricultural Science and Technology Innovation Fund(16A1132)Science and Technology Major Project of Anhui Province(15CZZ03132)Special Fund for Talent Development in Anhui Province(13C1109)~~
文摘In order to solve the drifting away of thermal fog droplets during thermal spraying and the incompatibility between fog droplet carrier and conventional com- mercial agro-chemicals, the fog droplet carrier, surfactant, condensation nucleus ma- terial and antifreeze, dispersant, thickener and defoamer were screened and assem- bled to develop a thermal fog sedimentation stabilizer in this study, thereby provid- ing technical support for application and promotion of thermal spraying technology in pest and disease control in crops.
基金Supported by the Science and Technology Support Key Project of 12th Five-Year of China(2011BAD20B00-4)~~
文摘The influence of processing parameters on the precision of parts fabricated by fused deposition modeling （FDM） technology is studied based on a series of performed experiments. Processing parameters of FDM in terms of wire-width compensation, extrusion velocity, filing velocity, and layer thickness are chosen as the control fac- tors. Robust design analysis and multi-index fuzzy comprehensive assessment method are used to obtain the opti- mal parameters. Results show that the influencing degrees of these four factors on the precision of as-processed parts are different. The optimizations of individual parameters and their combined effects are of the same impor- tance for a high precision manufacturing.
基金Project(2011CB605502)supported by the National Basic Research Program of ChinaProject(B08040)supported by Introducing Talents of Discipline to Universities,China
文摘Microstructure stability of in situ synthesized Ti2AlN/Ti-48Al-2Cr-2Nb composite during aging at 900 ℃ was investigated by XRD, OM and TEM, and the unreinforced Ti-48Al-2Cr-2Nb alloy was also examined for comparison. The result showed that in the TiAl alloy,α2 lamellae thinned and were broken down, and became discontinuous with increasing aging time. The decomposition ofα2 lamella toγ which was characterized by parallel decomposition and breakdown ofα2 lamellae led to the degradation of the lamellar structure. While in the composite, lamellar structure remained relatively stable even after aging at 900 ℃ for 100 h. No breakdown ofα2 lamellae except parallel decomposition and precipitation of fine nitride particles was observed. The better microstructural stability of the composite was mainly attributed to the precipitation of Ti2AlN particles at theα2/γ interface which played an important role in retarding the coarsening of lamellar microstructure in the matrix of composite.
文摘Ni-TiN nanocomposite films were produced from a Ni plating bath containing TiN nanoparticles by using dc electroplating method. The structure and surface morphology of Ni-TiN composite coatings were analyzed by atom force microscope, X-ray diffraction, and trans- mission electron microscopy. Meanwhile, the anti-corrosion properties, hardness and ther- mostability of Ni-TiN nanocomposite films were also investigated and compared with the traditional polycrystalline Ni coatings. The results show that, compared with the traditional polycrystalline Ni film, Ni-TiN nanocomposite coatings display much better corrosion resistance, higher film hardness, and thermal stability. In addition, the hardness of Ni-TiN nanocomposite coatings decreases slightly with the increase of electroplating current density, which may be due to the synergism of hydrogen evolution and faster nucleation/growth rate of nickel crystallites.
基金Projects(2018YFC1901601,2018YFC1901604,2018YFC1901605) supported by the National Key Research and Development Program of ChinaProject(201806375047) supported by the Visiting Scholar of China Scholarship CouncilProject(51404296) supported by the Young Scientists Fund of the National Natural Science Foundation of China
文摘To achieve a safe treatment of arsenic-containing acid wastewater,a new process was proposed,including arsenic removal via sulfide precipitation and hydrothermal mineralization stabilization.Under optimal conditions of sulfide precipitation,99.65%of arsenic from wastewater was precipitated in the form of amorphous As2S3.The As leaching concentration of amorphous As2S3 in TCLP(toxicity characteristic leaching procedure)test was up to 212.97 mg/L,therefore,hydrothermal mineralization was adopted to improve the stability of amorphous As2S3.The results showed that the As leaching concentration of mineralized As2S3 was only 4.82 mg/L.Furthermore,the amorphous As2S3 could be transformed into crystallized As2S3(orpiment)in the presence of mineralizer Na2SO4.Simultaneously,the As leaching concentration of crystallized As2S3 was further reduced to 3.86 mg/L.Hydrothermal mineralization was an effective method for the stabilization of As2S3.Therefore,this process has a greater application in the treatment of arsenic-containing wastewater.
基金funded by the European project EUROFLEETS (Seventh Framework Programme, No. 228344)
文摘Seafloor elongated depressions are indicators of gas seepage or slope instability. Here we report a sequence of slopeparallel elongated depressions that link to headwalls of sediment slides on upper slope. The depressions of about 250 m in width and several kilometers in length are areas of focused gas discharge indicated by bubble-release into the water column and methane enriched pore waters. Sparker seismic profiles running perpendicular and parallel to the coast, show gas migration pathways and trapped gas underneath these depressions with bright spots and seismic blanking. The data indicate that upward gas migration is the initial reason for fracturing sedimentary layers. In the top sediment where two young stages of landslides can be detected, the slopeparallel sediment weakening lengthens and deepens the surficial fractures, creating the elongated depressions in the seafloor supported by sediment erosion due to slope-parallel water currents.
