Acyl chloride can efficiently be converted into anhydride under solid liquid phase transfer catalysis by using bis(triphenylphosphine)cobalt dichloride or bis(triphenylphospine)palladium dichloride as the catalyst.
Liquid phase oxidation of toluene is an environmental benign route for the production of benzoic acid.In a φ48mm bubble column reactor,the commercial process of toluene liquid phase oxidation was conducted with Co(CH...Liquid phase oxidation of toluene is an environmental benign route for the production of benzoic acid.In a φ48mm bubble column reactor,the commercial process of toluene liquid phase oxidation was conducted with Co(CH3COO)2.4H2O as catalyst.The Co2+ concentration [Co2+] was determined by extraction spectrophotometry and hereby the Co3+ concentration [Co3+] was obtained by mass balance.The results showed that [Co3+] reached the maximum at about 25-30min.[Co3+] increased with increasing Co catalyst amount at total Co concentration<150 mg.L-1 of toluene.The conversion of toluene,yield and selectivity of benzoic acid increased with the increasing [Co3+/Co2+] max.A high [Co3+] and a high [Co3+]/[Co2+] ratio are beneficial to the reaction.展开更多
Phase equilibria of the R-Fe-Co pseudoternary system with R≤33.3%(mole fraction, R=Sm 0.5Dy 0.5) were determined in an isothermal section at 1 073 K and a vertical section of RFe 2-RCo 2 by using OM, X-ray diffractom...Phase equilibria of the R-Fe-Co pseudoternary system with R≤33.3%(mole fraction, R=Sm 0.5Dy 0.5) were determined in an isothermal section at 1 073 K and a vertical section of RFe 2-RCo 2 by using OM, X-ray diffractometer, EPMA DTA techniques. There are seven intermetallic phases: (Sm, Dy)(Fe, Co) 2, (Sm, Dy)(Fe, Co) 3, (Sm, Dy) 6(Fe, Co) 23, (Sm, Dy) 2(Fe, Co) 7, (Sm, Dy)(Fe, Co) 5, Th 2Ni 17-type and Th 2Zn 17-type (Sm, Dy) 2(Fe, Co) 17. The (Sm, Dy) 6(Fe, Co) 23 phase dissolves 36% Co(mole fraction) at 1 073 K. However, the (Sm, Dy) 2(Fe, Co) 7 phase in R 2(Fe 1-xCo x) 7 alloys dissolves about 19% Fe(mole fraction) at 1 073 K.展开更多
A new technology, the two-step transient liquid phase diffusion bonding （TLP-DB） technology for cobalt-based K640 superalloy, was investigated. The method consists of a short-time high temperature heating to melt in...A new technology, the two-step transient liquid phase diffusion bonding （TLP-DB） technology for cobalt-based K640 superalloy, was investigated. The method consists of a short-time high temperature heating to melt interlayer followed by isothermal solidification of liquid phase at a lower temperature than that of the conventional TLP-DB. The result indicates that the two-step TLP-DB can reliably produce an ideal joint with uniform chemical composition, which is superior to the joint welded by conventional TLP-DB in microstructure and mechanical properties. Bonding parameters of new process are 1 250℃ for 0. 5 h and 1 180℃ for 3 h. The high-temperature tensile strength of the joint by two-step TLP-DB reaches 74% of that of the base material on an equal basis, but the high-temperature tensile strength of the joint by conventional TLP-DB is only 58% of that of the base material.展开更多
文摘Acyl chloride can efficiently be converted into anhydride under solid liquid phase transfer catalysis by using bis(triphenylphosphine)cobalt dichloride or bis(triphenylphospine)palladium dichloride as the catalyst.
基金Supported by the National Natural Science Foundation of China （20576081, 20736009） and the Ph.D. Programs Foundation of Ministry of Education of China （20070610128）.
文摘Liquid phase oxidation of toluene is an environmental benign route for the production of benzoic acid.In a φ48mm bubble column reactor,the commercial process of toluene liquid phase oxidation was conducted with Co(CH3COO)2.4H2O as catalyst.The Co2+ concentration [Co2+] was determined by extraction spectrophotometry and hereby the Co3+ concentration [Co3+] was obtained by mass balance.The results showed that [Co3+] reached the maximum at about 25-30min.[Co3+] increased with increasing Co catalyst amount at total Co concentration<150 mg.L-1 of toluene.The conversion of toluene,yield and selectivity of benzoic acid increased with the increasing [Co3+/Co2+] max.A high [Co3+] and a high [Co3+]/[Co2+] ratio are beneficial to the reaction.
文摘Phase equilibria of the R-Fe-Co pseudoternary system with R≤33.3%(mole fraction, R=Sm 0.5Dy 0.5) were determined in an isothermal section at 1 073 K and a vertical section of RFe 2-RCo 2 by using OM, X-ray diffractometer, EPMA DTA techniques. There are seven intermetallic phases: (Sm, Dy)(Fe, Co) 2, (Sm, Dy)(Fe, Co) 3, (Sm, Dy) 6(Fe, Co) 23, (Sm, Dy) 2(Fe, Co) 7, (Sm, Dy)(Fe, Co) 5, Th 2Ni 17-type and Th 2Zn 17-type (Sm, Dy) 2(Fe, Co) 17. The (Sm, Dy) 6(Fe, Co) 23 phase dissolves 36% Co(mole fraction) at 1 073 K. However, the (Sm, Dy) 2(Fe, Co) 7 phase in R 2(Fe 1-xCo x) 7 alloys dissolves about 19% Fe(mole fraction) at 1 073 K.
基金Acknowledgments This work has benefited from the use of 1） Los Alamos Neutron Science Facility at Los Alamos National Laboratory and 2） ISIS Pulsed Neutron and Muon Source at Rutherford-Appleton Laboratory. The financial support of the National Science Foundation＇s 1） International Materials Institutes （IMI） under DMR-0231320, 2） Integrative Graduate Education and Research Training （IGERT） under DGE-9987548, 3） Combined Research and Curriculum Development （CRCD） under EEC-9527527 and EEC-0203415, and 4） Major Research Instrumentation （MRI） under DMR-0231320 at the University of Tennessee with Dr HUBER C, Dr Van HARTESVELDT C J, Dr DUTTA D, Dr JENNINGS W, Dr G0LDBERG L, Ms P0ATS M, and Dr B0ULDIN C R as the Program Directors, is greatly appreciated. Additional funding for this project was gratefully received from the Tennessee Advanced Materials Laboratory, with Prof. PLUMMER E W as the Director.
文摘A new technology, the two-step transient liquid phase diffusion bonding （TLP-DB） technology for cobalt-based K640 superalloy, was investigated. The method consists of a short-time high temperature heating to melt interlayer followed by isothermal solidification of liquid phase at a lower temperature than that of the conventional TLP-DB. The result indicates that the two-step TLP-DB can reliably produce an ideal joint with uniform chemical composition, which is superior to the joint welded by conventional TLP-DB in microstructure and mechanical properties. Bonding parameters of new process are 1 250℃ for 0. 5 h and 1 180℃ for 3 h. The high-temperature tensile strength of the joint by two-step TLP-DB reaches 74% of that of the base material on an equal basis, but the high-temperature tensile strength of the joint by conventional TLP-DB is only 58% of that of the base material.
