为合理地分析超声速发动机在起降着陆(landing and take-off,LTO)循环中的污染物排放特性,构建了基于CFM56-7B27核心机的超声速发动机模型。通过建立排放计算模型计算了LTO污染物排放指数(emission index,EI),并分析了其排放特性;研究...为合理地分析超声速发动机在起降着陆(landing and take-off,LTO)循环中的污染物排放特性,构建了基于CFM56-7B27核心机的超声速发动机模型。通过建立排放计算模型计算了LTO污染物排放指数(emission index,EI),并分析了其排放特性;研究爬升和慢车阶段污染物排放特性对LTO超声速模式标准设定的影响,进而确定更具代表性的LTO超声速模式标准。分析结果表明:不同LTO阶段的推力设置(thrust setting,TS)和模式时间(time in mode,TIM)对污染物排放特性的影响存在差异性;在LTO标准研究方面,60%额定推力、2 min模式时间的爬升点氮氧化物的排放质量/额定推力更接近于超声速爬升轨迹,慢车点TS在不低于10%额定推力时更能满足污染物(一氧化碳、未燃烧碳氢)排放特性所限制的燃烧效率要求,因此以60%额定推力、2 min模式时间作为LTO超声速模式爬升点标准、以TS不低于10%额定推力作为LTO超声速模式慢车点标准更为合理。展开更多
The usual mixed sensitivity H ∞ design is not suitable for servo design, because there exist pole/zero cancellations and the resulting control law will include a pure differentiation factor. This paper presents an al...The usual mixed sensitivity H ∞ design is not suitable for servo design, because there exist pole/zero cancellations and the resulting control law will include a pure differentiation factor. This paper presents an alternative design, i.e. the PS/T two block design. It is proved that in the PS/T problem there is no cancellation of the plant poles by the controller. The PS/T problem can take full advantage of the two block design approach: simplicity and intuition. And the use of PS in design is more practical for it represents the system’s disturbance rejection performance. The PS/T two block design details are discussed and illustrated by an example. The results of this paper can also be used for MIMO systems.展开更多
The main subject of this work is about the effect of T-ZnOw on the toughness and stiffness of polystyrene (PS).In order to avoid the rupture of T-ZnOw during the melt processing,T-ZnOw/PS composites were obtained via ...The main subject of this work is about the effect of T-ZnOw on the toughness and stiffness of polystyrene (PS).In order to avoid the rupture of T-ZnOw during the melt processing,T-ZnOw/PS composites were obtained via the combination of solution blending and injection moulding methods.Although the tensile strength of the composites decreases slightly,the impact strength and tensile modulus increase with the increase of the T-ZnOw content in the matrix.The stiffness and toughness of the composites are enhance...展开更多
The effect of different sulfonation degree on properties of sulfonated syndiotactic polystyrene(S s PS) was investigated by 1H NMR, 13 C NMR,FTIR,DSC and WAXD.The results of 13 C NMR showed that a peak at δ =145 5 ap...The effect of different sulfonation degree on properties of sulfonated syndiotactic polystyrene(S s PS) was investigated by 1H NMR, 13 C NMR,FTIR,DSC and WAXD.The results of 13 C NMR showed that a peak at δ =145 5 appeared in all S s PS spectra,which proved that the syndiotactic structure of syndiotactic polystyrene( s PS) still existed in S s PS.With increasing degree of sulfonition,the chemical shifts of C 1 and C\|3 for sulfonated benzene ring turned out to be wider. 1 H NMR spectra showed that C\|3 for sulfonated benzene ring had a chemical shift of 7 66.FTIR spectra showed that sulfonic acid groups were introduced on the para position of benzene rings and with increasing sulfonation degree,the absorption strength of 612/1600 cm 1 ,834/1600cm -1 increased,but the absorption strength of 1078/1600cm -1 decreased.The absorption of ～1030cm -1 ,～1179cm -1 ,～1217cm -1 appeared when the sulfonation degree was higher that 6%. s PS and S s PS H 2 2 had absorption at 975 and 943cm -1 and also had double peaks around ～1175cm -1 ;DSC showed that with increasing sulfonation degree, the glass transition temperature increased, the melt temperature,crystallization temperature and crystallization degree decreased;S s PS couldn’t crystallize when sulfonation degree was higher that 6mol%;WAXD proved that s PS had the α and β crystal types, however,S s PS with 2 2% sulfonation degree only had the β crystal type, and S s PS with 6 1% sulfonation degree didn’t crystallize.展开更多
文摘为合理地分析超声速发动机在起降着陆(landing and take-off,LTO)循环中的污染物排放特性,构建了基于CFM56-7B27核心机的超声速发动机模型。通过建立排放计算模型计算了LTO污染物排放指数(emission index,EI),并分析了其排放特性;研究爬升和慢车阶段污染物排放特性对LTO超声速模式标准设定的影响,进而确定更具代表性的LTO超声速模式标准。分析结果表明:不同LTO阶段的推力设置(thrust setting,TS)和模式时间(time in mode,TIM)对污染物排放特性的影响存在差异性;在LTO标准研究方面,60%额定推力、2 min模式时间的爬升点氮氧化物的排放质量/额定推力更接近于超声速爬升轨迹,慢车点TS在不低于10%额定推力时更能满足污染物(一氧化碳、未燃烧碳氢)排放特性所限制的燃烧效率要求,因此以60%额定推力、2 min模式时间作为LTO超声速模式爬升点标准、以TS不低于10%额定推力作为LTO超声速模式慢车点标准更为合理。
文摘The usual mixed sensitivity H ∞ design is not suitable for servo design, because there exist pole/zero cancellations and the resulting control law will include a pure differentiation factor. This paper presents an alternative design, i.e. the PS/T two block design. It is proved that in the PS/T problem there is no cancellation of the plant poles by the controller. The PS/T problem can take full advantage of the two block design approach: simplicity and intuition. And the use of PS in design is more practical for it represents the system’s disturbance rejection performance. The PS/T two block design details are discussed and illustrated by an example. The results of this paper can also be used for MIMO systems.
基金the National Natural Science Foundation of China (No.50403019)also partly supported by the Opening Project of State Key Laboratory of Polymer Materials Engineering (Sichuan University).
文摘The main subject of this work is about the effect of T-ZnOw on the toughness and stiffness of polystyrene (PS).In order to avoid the rupture of T-ZnOw during the melt processing,T-ZnOw/PS composites were obtained via the combination of solution blending and injection moulding methods.Although the tensile strength of the composites decreases slightly,the impact strength and tensile modulus increase with the increase of the T-ZnOw content in the matrix.The stiffness and toughness of the composites are enhance...
文摘The effect of different sulfonation degree on properties of sulfonated syndiotactic polystyrene(S s PS) was investigated by 1H NMR, 13 C NMR,FTIR,DSC and WAXD.The results of 13 C NMR showed that a peak at δ =145 5 appeared in all S s PS spectra,which proved that the syndiotactic structure of syndiotactic polystyrene( s PS) still existed in S s PS.With increasing degree of sulfonition,the chemical shifts of C 1 and C\|3 for sulfonated benzene ring turned out to be wider. 1 H NMR spectra showed that C\|3 for sulfonated benzene ring had a chemical shift of 7 66.FTIR spectra showed that sulfonic acid groups were introduced on the para position of benzene rings and with increasing sulfonation degree,the absorption strength of 612/1600 cm 1 ,834/1600cm -1 increased,but the absorption strength of 1078/1600cm -1 decreased.The absorption of ～1030cm -1 ,～1179cm -1 ,～1217cm -1 appeared when the sulfonation degree was higher that 6%. s PS and S s PS H 2 2 had absorption at 975 and 943cm -1 and also had double peaks around ～1175cm -1 ;DSC showed that with increasing sulfonation degree, the glass transition temperature increased, the melt temperature,crystallization temperature and crystallization degree decreased;S s PS couldn’t crystallize when sulfonation degree was higher that 6mol%;WAXD proved that s PS had the α and β crystal types, however,S s PS with 2 2% sulfonation degree only had the β crystal type, and S s PS with 6 1% sulfonation degree didn’t crystallize.
