A thermodynamic model of hydrogen induced silicon surface layer splitting with the help of an oxidized silicon wafer bonded is proposed.Wafer splitting is the result of lateral growth of hydrogen blisters in the enti...A thermodynamic model of hydrogen induced silicon surface layer splitting with the help of an oxidized silicon wafer bonded is proposed.Wafer splitting is the result of lateral growth of hydrogen blisters in the entire implanted hydrogen region during annealing.The blister growth rate depends on the effective activation energies of both hydrogen complex dissociation and hydrogen diffusion.The hydrogen blister radius was studied as the function of annealing time,annealing temperature and implantation dose.The critical radius was obtained according to the Griffith energy condition.The time required for wafer splitting at the cut temperature was calculated in accordance with the growth of hydrogen blisters.展开更多
Nickel-based superalloys with and without Co by partial replacement of W were prepared using double vacuum melting.A comparison of the oxidation in air and hot corrosion behaviors under molten 75 wt.%Na2 SO4+25 wt.%Na...Nickel-based superalloys with and without Co by partial replacement of W were prepared using double vacuum melting.A comparison of the oxidation in air and hot corrosion behaviors under molten 75 wt.%Na2 SO4+25 wt.%NaCl at 900℃were systematically investigated.The results showed that partial replacement of W with Co promoted the formation of chromia scale and consequently decreased the oxidation rate.Besides,the addition of Co also retarded the internal oxidation/nitridation of Al and consequently promoted the growth of Al_(2) O3 scale,which further decreased the scaling rate and improved the adhesion of scale.Moreover,the addition of Co also further improved the hot corrosion resistance under molten Na2 SO4-NaCl salts.展开更多
TiO2/WS2/g-C3N4composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method.In this process,the WS2/g-C3N4nano-sheets were prepared by liquid-exfoliation method from the bulk WS2and C3N4in the...TiO2/WS2/g-C3N4composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method.In this process,the WS2/g-C3N4nano-sheets were prepared by liquid-exfoliation method from the bulk WS2and C3N4in the alcohol system,and then the TiO2nanoparticles(NPs)grew on the WS2/g-C3N4nano-sheets by in-situ synthesized technique.The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of methyl orange(MO).The results showed that the as-prepared samples exhibited higher photocatalytic activities as compared to the pure TiO2,g-C3N4and TiO2/g-C3N4composite.The enhanced photocatalytic activities of TiO2/WS2/g-C3N4photocatalysts could be attributed to the synergistic effect of heterostructure between TiO2NPs and WS2/g-C3N4nano-sheets,which could efficiently improve the separation of photogenerated electron/hole pairs and utilization efficiency of photons.The quenching tests of radicals indicated that?O2?had crucial effect on degradation of MO,which demonstrated that?O2?was the main active radical in photocatalytic reaction process.展开更多
Large-scale production of graphene and sub- sequent sample engineering is the key for fully-realizing the potential applications proposed to this intriguing two-dimensional nanomaterial. Herein, smart graphene dispers...Large-scale production of graphene and sub- sequent sample engineering is the key for fully-realizing the potential applications proposed to this intriguing two-dimensional nanomaterial. Herein, smart graphene dispersions with low defects and thermo-responsive properties can be obtained by liquid phase exfoliation of graphite using an alkylated Percec monodendron （3,4,5-trioctadecy- loxybenzaldehyde, 1） as the stabilizing reagent. By simply changing the temperature, the dispersed graphene and 1 can be detached, leading to the recovery of both components. Besides noncovalent wrapping, the stabilizing reagent 1 can be also covalently attached to graphene through [3＋2] cycloaddition. The covalently functionalized graphene sheets show improved dispersibility in organic solvents compared to the pristine graphene, which opens the door for their applications in various polymer matrixes. The strategy demonstrated here provides a new methodology to get smart graphene dispersions with multiple functions.展开更多
文摘A thermodynamic model of hydrogen induced silicon surface layer splitting with the help of an oxidized silicon wafer bonded is proposed.Wafer splitting is the result of lateral growth of hydrogen blisters in the entire implanted hydrogen region during annealing.The blister growth rate depends on the effective activation energies of both hydrogen complex dissociation and hydrogen diffusion.The hydrogen blister radius was studied as the function of annealing time,annealing temperature and implantation dose.The critical radius was obtained according to the Griffith energy condition.The time required for wafer splitting at the cut temperature was calculated in accordance with the growth of hydrogen blisters.
基金financial supports from the Natural Science Foundation of Shandong Province,China(No.ZR2019MEE107)Shandong Jiaotong University“Climbing”Research Innovation Team Program,China(No.SDJTC1802)PhD Scientific Research Foundation of Shandong Jiaotong University,China(No.BS2018005)。
文摘Nickel-based superalloys with and without Co by partial replacement of W were prepared using double vacuum melting.A comparison of the oxidation in air and hot corrosion behaviors under molten 75 wt.%Na2 SO4+25 wt.%NaCl at 900℃were systematically investigated.The results showed that partial replacement of W with Co promoted the formation of chromia scale and consequently decreased the oxidation rate.Besides,the addition of Co also retarded the internal oxidation/nitridation of Al and consequently promoted the growth of Al_(2) O3 scale,which further decreased the scaling rate and improved the adhesion of scale.Moreover,the addition of Co also further improved the hot corrosion resistance under molten Na2 SO4-NaCl salts.
基金Projects(21376099,21546002)supported by the National Natural Science Foundation of China
文摘TiO2/WS2/g-C3N4composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method.In this process,the WS2/g-C3N4nano-sheets were prepared by liquid-exfoliation method from the bulk WS2and C3N4in the alcohol system,and then the TiO2nanoparticles(NPs)grew on the WS2/g-C3N4nano-sheets by in-situ synthesized technique.The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of methyl orange(MO).The results showed that the as-prepared samples exhibited higher photocatalytic activities as compared to the pure TiO2,g-C3N4and TiO2/g-C3N4composite.The enhanced photocatalytic activities of TiO2/WS2/g-C3N4photocatalysts could be attributed to the synergistic effect of heterostructure between TiO2NPs and WS2/g-C3N4nano-sheets,which could efficiently improve the separation of photogenerated electron/hole pairs and utilization efficiency of photons.The quenching tests of radicals indicated that?O2?had crucial effect on degradation of MO,which demonstrated that?O2?was the main active radical in photocatalytic reaction process.
基金supported by the Hundred Talents Program of Chinese Academy of Sciences(Y20245YBR1)the National Natural Science Foundation of China(21402215 and 61474124)the financial support from Shandong Province Higher Education Science and Technology Program(J16LA01)
文摘Large-scale production of graphene and sub- sequent sample engineering is the key for fully-realizing the potential applications proposed to this intriguing two-dimensional nanomaterial. Herein, smart graphene dispersions with low defects and thermo-responsive properties can be obtained by liquid phase exfoliation of graphite using an alkylated Percec monodendron （3,4,5-trioctadecy- loxybenzaldehyde, 1） as the stabilizing reagent. By simply changing the temperature, the dispersed graphene and 1 can be detached, leading to the recovery of both components. Besides noncovalent wrapping, the stabilizing reagent 1 can be also covalently attached to graphene through [3＋2] cycloaddition. The covalently functionalized graphene sheets show improved dispersibility in organic solvents compared to the pristine graphene, which opens the door for their applications in various polymer matrixes. The strategy demonstrated here provides a new methodology to get smart graphene dispersions with multiple functions.
