The lightweight worsted fabric made of Sirofil yarn was developed and its textile performance was studied. By means of conventional testing, KES and FAST, it is concluded that with the coordination of proper fabric de...The lightweight worsted fabric made of Sirofil yarn was developed and its textile performance was studied. By means of conventional testing, KES and FAST, it is concluded that with the coordination of proper fabric design and processing technique, the performance of this innovative fabric is superior to that of the conventional lightweight fabric Furthermore, it is predicted from the relevant parameters that its processability in the following suit manufacture is very desirable.展开更多
A self-tuning adaptive controller is presented which is used for the adaptive control (AC) of drlling process. The parameters of the controller can be regulated in-processly by on line system identification, so as to ...A self-tuning adaptive controller is presented which is used for the adaptive control (AC) of drlling process. The parameters of the controller can be regulated in-processly by on line system identification, so as to fit the variation of the cutting conditions. This control method has been successfully applied to the adaptive control of drilling process. The experimental results indicate that the controller has the ability to adapt to the variation of the cutting process parameters and is good in performance.展开更多
To improve the processability and thermal stability of polyimide, a series of novel phenylethynyl-endcapped oligoimides （PEPA-oligoimides） with calculated molecular weights （M_nC） were successfully prepared from t...To improve the processability and thermal stability of polyimide, a series of novel phenylethynyl-endcapped oligoimides （PEPA-oligoimides） with calculated molecular weights （M_nC） were successfully prepared from thermal imidization of 4,4＇-（9-fluorenylidene） dianiline （BAFL） as fluorenyl diamine, 4,4＇-oxy-diphthalic anhydride （ODPA） as aromatic dianhydride and 4-phenylethynylphthalic anhydride （4-PEPA） acted as reactive end-capping reagent at elevated temperatures. Experiment results indicated that the oligoimides were the mixtures of PEPA-endcapped oligomers with different degrees of polymerization characterized by MALDI-TOF mass spectra. The influence of chemical structures on the melt processabilities of the oligoimides, the thermal, dielectric and mechanical properties of the thermoset resins was studied. The typical oligoimide resin owned minimum melt viscosity of 0.2 Pa＇s at around 310 ℃and wide melting processing window, suitable for resin transfer molding （RTM）. Besides, its corresponding thermal-cured polyimide resin possessed glass transition temperature （T_g） as high as 514 ℃. The dielectric constants of polyimide resins decreased from 3.15 to 2.80 by reducing the M_nC. The mechanical properties of the polyimide neat resins were improved gradually with increasing M_nC. Finally, the carbon fiber/polyimide （C_f/PI） composite laminates showed excellent mechanical strength retention rate at 350 ℃, might be long-term served at extremely high temperature in aerospace and aviation field.展开更多
基金This research is one of the national "ninth five" key projects, supported by China Textile University and Shanghai Wool & Flax Research Institute.
文摘The lightweight worsted fabric made of Sirofil yarn was developed and its textile performance was studied. By means of conventional testing, KES and FAST, it is concluded that with the coordination of proper fabric design and processing technique, the performance of this innovative fabric is superior to that of the conventional lightweight fabric Furthermore, it is predicted from the relevant parameters that its processability in the following suit manufacture is very desirable.
文摘A self-tuning adaptive controller is presented which is used for the adaptive control (AC) of drlling process. The parameters of the controller can be regulated in-processly by on line system identification, so as to fit the variation of the cutting conditions. This control method has been successfully applied to the adaptive control of drilling process. The experimental results indicate that the controller has the ability to adapt to the variation of the cutting process parameters and is good in performance.
基金financially supported by the National Basic Research Program of China(No.2014CB643604)
文摘To improve the processability and thermal stability of polyimide, a series of novel phenylethynyl-endcapped oligoimides （PEPA-oligoimides） with calculated molecular weights （M_nC） were successfully prepared from thermal imidization of 4,4＇-（9-fluorenylidene） dianiline （BAFL） as fluorenyl diamine, 4,4＇-oxy-diphthalic anhydride （ODPA） as aromatic dianhydride and 4-phenylethynylphthalic anhydride （4-PEPA） acted as reactive end-capping reagent at elevated temperatures. Experiment results indicated that the oligoimides were the mixtures of PEPA-endcapped oligomers with different degrees of polymerization characterized by MALDI-TOF mass spectra. The influence of chemical structures on the melt processabilities of the oligoimides, the thermal, dielectric and mechanical properties of the thermoset resins was studied. The typical oligoimide resin owned minimum melt viscosity of 0.2 Pa＇s at around 310 ℃and wide melting processing window, suitable for resin transfer molding （RTM）. Besides, its corresponding thermal-cured polyimide resin possessed glass transition temperature （T_g） as high as 514 ℃. The dielectric constants of polyimide resins decreased from 3.15 to 2.80 by reducing the M_nC. The mechanical properties of the polyimide neat resins were improved gradually with increasing M_nC. Finally, the carbon fiber/polyimide （C_f/PI） composite laminates showed excellent mechanical strength retention rate at 350 ℃, might be long-term served at extremely high temperature in aerospace and aviation field.
