Stable operation of aircraft engine compressions is constrained by rotating surge. In this paper, an approximate nonlinear surge margin model of aircraft engine compression system by using equilibrium manifold is pres...Stable operation of aircraft engine compressions is constrained by rotating surge. In this paper, an approximate nonlinear surge margin model of aircraft engine compression system by using equilibrium manifold is presented. Firstly, this paper gives an overview of the current state of modeling aerodynamic flow instabilities in engine compressors. Secondly, the expansion form of equilibrium manifold is introduced, and the choosing scheduling variable method is discussed. Then, this paper also gives the identification procedure of modeling the approximate nonlinear model. Finally, the modeling and simulations with high pressure （liP） compressor surge margin of the aircraft engine show that this real-time model has the same accuracy with the thermody- namic model, but has simpler structure and shorter computation time.展开更多
It is an unarguable fact that the urban-rural dual structure led to two different results. On the one hand,it had been playing a great role in the city development and prosperity,and on the other hand,it had led the s...It is an unarguable fact that the urban-rural dual structure led to two different results. On the one hand,it had been playing a great role in the city development and prosperity,and on the other hand,it had led the slow development of rural economy and the income gap between rural and urban areas. The government makes efforts to promote the process of urbanization to maintain the sustained development of China's economy and economic transformation which are the two needs of the Chinese reality. But in the top-level design of the policy,the government did not give a fair profits distribution to all social groups. On the contrary,the result of urban development is based on the expense of a part of the people's interests in exchange for the interests of another parts of the people,and especially on the government expropriation in the process of urban expansion. Under Land Administration Law of the People's Republic of China,the government monopolized the expropriation right of the rural land,and the rural collectives and farmers as the land owner and constructors respectively have no rights to decide the land use purposes. In fact,they are forced to accept the land compensation,and because of the little bargaining rights,they gain little from the land value increment. Comparatively,the governments became the biggest beneficiary who made use of the land as a source and capital to earn the achievement in their official career and more money required by the urban development. The paper mainly analyzes the current situation of the distribution of the land added value,elaborates the reasons why the government strives for the land interests,and discusses what farmers lose in the government expropriation. Last but not lest,the author reflects on the land reform and gives a proposal on distribution of land added value.展开更多
Late last November, the CITIC Industrial Bank, a Beijing-based lender, stepped up its internal restructuring process after being given the green light from the China Banking Regulatory Commission (CBRC), the nation...Late last November, the CITIC Industrial Bank, a Beijing-based lender, stepped up its internal restructuring process after being given the green light from the China Banking Regulatory Commission (CBRC), the nation's banking watchdog, to change its name to China CITIC Bank. The "Industrial"展开更多
基金National Natural Science Foundation of China (61104146)Innovation Plan of Aero Engine Complex System Safety by the Ministry of Education Chang Jiang Scholars of China (IRT0905)
文摘Stable operation of aircraft engine compressions is constrained by rotating surge. In this paper, an approximate nonlinear surge margin model of aircraft engine compression system by using equilibrium manifold is presented. Firstly, this paper gives an overview of the current state of modeling aerodynamic flow instabilities in engine compressors. Secondly, the expansion form of equilibrium manifold is introduced, and the choosing scheduling variable method is discussed. Then, this paper also gives the identification procedure of modeling the approximate nonlinear model. Finally, the modeling and simulations with high pressure （liP） compressor surge margin of the aircraft engine show that this real-time model has the same accuracy with the thermody- namic model, but has simpler structure and shorter computation time.
文摘It is an unarguable fact that the urban-rural dual structure led to two different results. On the one hand,it had been playing a great role in the city development and prosperity,and on the other hand,it had led the slow development of rural economy and the income gap between rural and urban areas. The government makes efforts to promote the process of urbanization to maintain the sustained development of China's economy and economic transformation which are the two needs of the Chinese reality. But in the top-level design of the policy,the government did not give a fair profits distribution to all social groups. On the contrary,the result of urban development is based on the expense of a part of the people's interests in exchange for the interests of another parts of the people,and especially on the government expropriation in the process of urban expansion. Under Land Administration Law of the People's Republic of China,the government monopolized the expropriation right of the rural land,and the rural collectives and farmers as the land owner and constructors respectively have no rights to decide the land use purposes. In fact,they are forced to accept the land compensation,and because of the little bargaining rights,they gain little from the land value increment. Comparatively,the governments became the biggest beneficiary who made use of the land as a source and capital to earn the achievement in their official career and more money required by the urban development. The paper mainly analyzes the current situation of the distribution of the land added value,elaborates the reasons why the government strives for the land interests,and discusses what farmers lose in the government expropriation. Last but not lest,the author reflects on the land reform and gives a proposal on distribution of land added value.
文摘Late last November, the CITIC Industrial Bank, a Beijing-based lender, stepped up its internal restructuring process after being given the green light from the China Banking Regulatory Commission (CBRC), the nation's banking watchdog, to change its name to China CITIC Bank. The "Industrial"
