The particularity and practicality of harmony operations of close-coupling multiple helicopters indicate that the researches on it are urgent and necessary, Using the model that describes two hovering helicopters carr...The particularity and practicality of harmony operations of close-coupling multiple helicopters indicate that the researches on it are urgent and necessary, Using the model that describes two hovering helicopters carrying one heavy load, an inertia coordinate system and body coordinate systems of each sub-system are established. A nonlinear force model is established too. The equilibrium computation results can be regarded as the reference control inputs of the flight control system under hovering or low-speed flight condition. After the establishment of a translation kinematics model and a posture kinematics model, a coupling dynamics model of the multiple helicopter system is set up. The results can also be regarded as the base to analyze stabilization and design a controller for a close-coupling multiple helicopters harmony operation system.展开更多
In order to meet the needs of work in numerical weather forecast and in numerical simulations for climate change and ocean current, a kind of difference scheme in high precision in the time direction developed from th...In order to meet the needs of work in numerical weather forecast and in numerical simulations for climate change and ocean current, a kind of difference scheme in high precision in the time direction developed from the completely square-conservative difference scheme in explicit way is built by means of the Taylor expansion. A numerical test with 4-wave Rossby-Haurwitz waves on them and an application of them on the monthly mean current the of South China Sea are carried out, from which, it is found that not only do the new schemes have high harmony and approximate precision but also can the time step of the schemes be lengthened and can much computational time be saved. Therefore, they are worth generalizing and applying.展开更多
Blast furnace （BF） ironmaking is dominant for reducing pollution emission and energy consumption in iron and steel industry, Under the increasingly strict environmental pressure, some innovative tech nologies of BF ...Blast furnace （BF） ironmaking is dominant for reducing pollution emission and energy consumption in iron and steel industry, Under the increasingly strict environmental pressure, some innovative tech nologies of BF ironmaking for environmental protection have been developed and applied in actual op- erating facilities. The current state of BF ironmaking in Europe, America, Japan, and China were briefly overviewed. Moreover, some innovative BF ironmaking technologies aiming at environmental harmony and operation intellectualization in the world, such as waste gas recycling sintering, BF op eration with coke oven gas injection, ferro coke, lime coating coke, BF visualization and intellectuali zation, were roundly summarized. Finally, some discussion on the technologies was carried out and the development trends of BF ironmaking were pointed out. The review could provide references and supports for the progress of environment friendly technologies of BF ironmaking, thereby promoting their practical applications and achieving sustainable development of BF ironmaking, especially for Chinese ironmaking industry.展开更多
基金National Natural Science Foundation of China(60475039)
文摘The particularity and practicality of harmony operations of close-coupling multiple helicopters indicate that the researches on it are urgent and necessary, Using the model that describes two hovering helicopters carrying one heavy load, an inertia coordinate system and body coordinate systems of each sub-system are established. A nonlinear force model is established too. The equilibrium computation results can be regarded as the reference control inputs of the flight control system under hovering or low-speed flight condition. After the establishment of a translation kinematics model and a posture kinematics model, a coupling dynamics model of the multiple helicopter system is set up. The results can also be regarded as the base to analyze stabilization and design a controller for a close-coupling multiple helicopters harmony operation system.
文摘In order to meet the needs of work in numerical weather forecast and in numerical simulations for climate change and ocean current, a kind of difference scheme in high precision in the time direction developed from the completely square-conservative difference scheme in explicit way is built by means of the Taylor expansion. A numerical test with 4-wave Rossby-Haurwitz waves on them and an application of them on the monthly mean current the of South China Sea are carried out, from which, it is found that not only do the new schemes have high harmony and approximate precision but also can the time step of the schemes be lengthened and can much computational time be saved. Therefore, they are worth generalizing and applying.
基金support by the National Natural Science Foundation of China(Nos.50804008and 51374058)the China Postdoctoral Science Foundation(No.2016M601321)the Fundamental Research Funds of the Central Universities of China(No.N162503003)
文摘Blast furnace （BF） ironmaking is dominant for reducing pollution emission and energy consumption in iron and steel industry, Under the increasingly strict environmental pressure, some innovative tech nologies of BF ironmaking for environmental protection have been developed and applied in actual op- erating facilities. The current state of BF ironmaking in Europe, America, Japan, and China were briefly overviewed. Moreover, some innovative BF ironmaking technologies aiming at environmental harmony and operation intellectualization in the world, such as waste gas recycling sintering, BF op eration with coke oven gas injection, ferro coke, lime coating coke, BF visualization and intellectuali zation, were roundly summarized. Finally, some discussion on the technologies was carried out and the development trends of BF ironmaking were pointed out. The review could provide references and supports for the progress of environment friendly technologies of BF ironmaking, thereby promoting their practical applications and achieving sustainable development of BF ironmaking, especially for Chinese ironmaking industry.
