This paper reports the thermodynamics of reversible oxygen binding to a dicobalt di(meso-tetraphenylporphyrin) linked by a diamido- aliphatic chain in N, Ndimethylformamide solution. Thermodynamic values(standard stat...This paper reports the thermodynamics of reversible oxygen binding to a dicobalt di(meso-tetraphenylporphyrin) linked by a diamido- aliphatic chain in N, Ndimethylformamide solution. Thermodynamic values(standard state 101325 Pa O2): △G (298K)=-3.1kJ mol-1, △H (298K)=-37.1kJ·mol-1, △S (298K)=-114 J.mol-1K-1,Co:O2=1:1. The ESR parameters of the dioxygen complex in DMF at 133K are as follows: g=2.000, g=2.046, A= 15G, A =22G, The pressure of dioxygen necessary for half-oxygenation of the system (P1/2 =42.7kPa at 288K) is comparable with that for cobalt substituted human hemoglobin at T state.展开更多
The SiCf/SiC composites containing PyC interphase were prepared by chemical vapor infiltration process. The influences of thermal oxidation on the complex permittivity and microwave absorption properties of Si Cf/Si C...The SiCf/SiC composites containing PyC interphase were prepared by chemical vapor infiltration process. The influences of thermal oxidation on the complex permittivity and microwave absorption properties of Si Cf/Si C composites were investigated in the frequency range of 8.2-12.4 GHz. Both the real and imaginary parts of the complex permittivity decreased after thermal oxidation. The composites after 100 h thermal oxidation showed that reflection loss exceeded-10 d B in the frequency of 9.7-11.9 GHz and the minimum value was-11.4 d B at 11.0 GHz. The flexural strength of composites decreased but fracture behavior was improved obviously after thermal oxidation. These results indicate that the SiCf/SiC composites containing PyC interphase after thermal oxidation possess good microwave absorbing property and fracture behavior.展开更多
文摘This paper reports the thermodynamics of reversible oxygen binding to a dicobalt di(meso-tetraphenylporphyrin) linked by a diamido- aliphatic chain in N, Ndimethylformamide solution. Thermodynamic values(standard state 101325 Pa O2): △G (298K)=-3.1kJ mol-1, △H (298K)=-37.1kJ·mol-1, △S (298K)=-114 J.mol-1K-1,Co:O2=1:1. The ESR parameters of the dioxygen complex in DMF at 133K are as follows: g=2.000, g=2.046, A= 15G, A =22G, The pressure of dioxygen necessary for half-oxygenation of the system (P1/2 =42.7kPa at 288K) is comparable with that for cobalt substituted human hemoglobin at T state.
基金Project(51072165)supported by the National Natural Science Foundation of ChinaProject(201305)supported by the Fund of State Key Laboratory of Solidification Processing,ChinaProjects(2013JK0921,2013JK0922)supported by Shaanxi Provincial Education Department of China
文摘The SiCf/SiC composites containing PyC interphase were prepared by chemical vapor infiltration process. The influences of thermal oxidation on the complex permittivity and microwave absorption properties of Si Cf/Si C composites were investigated in the frequency range of 8.2-12.4 GHz. Both the real and imaginary parts of the complex permittivity decreased after thermal oxidation. The composites after 100 h thermal oxidation showed that reflection loss exceeded-10 d B in the frequency of 9.7-11.9 GHz and the minimum value was-11.4 d B at 11.0 GHz. The flexural strength of composites decreased but fracture behavior was improved obviously after thermal oxidation. These results indicate that the SiCf/SiC composites containing PyC interphase after thermal oxidation possess good microwave absorbing property and fracture behavior.
