Unlike the magma intrusion model,the in- situ melting hypothesis advanced in the lastdecade regards the upper crustas a closed system,and granite as the resultof the materialswithin system changing from order (protoli...Unlike the magma intrusion model,the in- situ melting hypothesis advanced in the lastdecade regards the upper crustas a closed system,and granite as the resultof the materialswithin system changing from order (protolith) to disorder (melts) and to new order(granite) with the variations of entropy of the system.The various geological and geochemi-cal data from the Mesozoic granitesof southeast China are explained logically and systemical-ly by the hypothesis,concluding that they should be originated from the melting of pro-toliths.According to the hypothesis,melts generated from in- situ melting are of layer- likewithin the crustand batholithsare the protruding parts of the uppersurface of the layer (de-fined as the Melting Interface,MI for short) .On the basis the author tries to discuss thesource of heatfor the Mesozoic crustal melting in southeast China.展开更多
To achieve the satellite formation control and the succeed formation missions, we present a new stealthy method to determine the relative states between formation satellites. In this method, the combination of a CCD c...To achieve the satellite formation control and the succeed formation missions, we present a new stealthy method to determine the relative states between formation satellites. In this method, the combination of a CCD camera and laser radar is used as the relative measure sensors. To reduce electromagnetic radiation, the laser radar works intermittently to minimize the probability of being discovered. And an unscented Kalman filter (UKF) is applied to estimate the relative states. The observability of this method is analyzed. The validity and effectiveness of the method is demonstrated in a typical application of formation relative navigation.展开更多
From a point of magmatic view,the rupturing Gondwana Supercontinent is registered on the South American shelf in continental flood basalts,mafic dyke swarms,basins rift and,to a lesser extent,by intrusions alkaline.Am...From a point of magmatic view,the rupturing Gondwana Supercontinent is registered on the South American shelf in continental flood basalts,mafic dyke swarms,basins rift and,to a lesser extent,by intrusions alkaline.Among those展开更多
In the field of philosophy of technology,the concept of mediation is central to understanding how technology shapes human experience and behavior.Our aim in this paper is to contribute to the understanding of technolo...In the field of philosophy of technology,the concept of mediation is central to understanding how technology shapes human experience and behavior.Our aim in this paper is to contribute to the understanding of technological mediation,in particular how and why it is possible.Technological mediation occurs within a mediation space between the technological realm and the user realm.In the technological realm,technology regularizes events and actions,while in the user realm,the user interprets the significative potential of the technology.This interpretation process is identical with use and involves the formation of user habits,which are constrained by technological,cognitive,and sociocultural factors.To provide a theoretical framework for our analysis,we propose the Semiotic Model of Technological Mediation(SMTM),which draws on Charles Peirceʼs semiotics.To illustrate our argument,we focus on assistive technology and provide a recurring example of the Medimi®Smart,a digital,comprehensive system for medication handling.展开更多
A new set of relative orbit elements（ROEs）is used to derive a new elliptical formation flying model.In-plane and out-of-plane motions can be completely decoupled,which benefts elliptical formation design.The inverse...A new set of relative orbit elements（ROEs）is used to derive a new elliptical formation flying model.In-plane and out-of-plane motions can be completely decoupled,which benefts elliptical formation design.The inverse transformation of the state transition matrix is derived to study the relative orbit control strategy.Impulsive feedback control laws are developed for both in-plane and out-of-plane relative motions.Control of in-plane and out-of-plane relative motions can be completely decoupled using the ROE-based feedback control law.A tangential impulsive control method is proposed to study the relationship of fuel consumption and maneuvering positions.An optimal analytical along-track impulsive control strategy is then derived.Different typical orbit maneuvers,including formation establishment,reconfguration,long-distance maneuvers,and formation keeping,are taken as examples to demonstrate the performance of the proposed control laws.The effects of relative measurement errors are also considered to validate the high accuracy of the proposed control method.展开更多
文摘Unlike the magma intrusion model,the in- situ melting hypothesis advanced in the lastdecade regards the upper crustas a closed system,and granite as the resultof the materialswithin system changing from order (protolith) to disorder (melts) and to new order(granite) with the variations of entropy of the system.The various geological and geochemi-cal data from the Mesozoic granitesof southeast China are explained logically and systemical-ly by the hypothesis,concluding that they should be originated from the melting of pro-toliths.According to the hypothesis,melts generated from in- situ melting are of layer- likewithin the crustand batholithsare the protruding parts of the uppersurface of the layer (de-fined as the Melting Interface,MI for short) .On the basis the author tries to discuss thesource of heatfor the Mesozoic crustal melting in southeast China.
文摘To achieve the satellite formation control and the succeed formation missions, we present a new stealthy method to determine the relative states between formation satellites. In this method, the combination of a CCD camera and laser radar is used as the relative measure sensors. To reduce electromagnetic radiation, the laser radar works intermittently to minimize the probability of being discovered. And an unscented Kalman filter (UKF) is applied to estimate the relative states. The observability of this method is analyzed. The validity and effectiveness of the method is demonstrated in a typical application of formation relative navigation.
文摘From a point of magmatic view,the rupturing Gondwana Supercontinent is registered on the South American shelf in continental flood basalts,mafic dyke swarms,basins rift and,to a lesser extent,by intrusions alkaline.Among those
文摘In the field of philosophy of technology,the concept of mediation is central to understanding how technology shapes human experience and behavior.Our aim in this paper is to contribute to the understanding of technological mediation,in particular how and why it is possible.Technological mediation occurs within a mediation space between the technological realm and the user realm.In the technological realm,technology regularizes events and actions,while in the user realm,the user interprets the significative potential of the technology.This interpretation process is identical with use and involves the formation of user habits,which are constrained by technological,cognitive,and sociocultural factors.To provide a theoretical framework for our analysis,we propose the Semiotic Model of Technological Mediation(SMTM),which draws on Charles Peirceʼs semiotics.To illustrate our argument,we focus on assistive technology and provide a recurring example of the Medimi®Smart,a digital,comprehensive system for medication handling.
基金supported by the Innovation Foundation of BUAA for PhD Graduates (No.YWF-12-RBYJ-024)the National Natural Science Foundation of China (No.11002008)National Basic Research Program of China (No.2009CB723906)
文摘A new set of relative orbit elements（ROEs）is used to derive a new elliptical formation flying model.In-plane and out-of-plane motions can be completely decoupled,which benefts elliptical formation design.The inverse transformation of the state transition matrix is derived to study the relative orbit control strategy.Impulsive feedback control laws are developed for both in-plane and out-of-plane relative motions.Control of in-plane and out-of-plane relative motions can be completely decoupled using the ROE-based feedback control law.A tangential impulsive control method is proposed to study the relationship of fuel consumption and maneuvering positions.An optimal analytical along-track impulsive control strategy is then derived.Different typical orbit maneuvers,including formation establishment,reconfguration,long-distance maneuvers,and formation keeping,are taken as examples to demonstrate the performance of the proposed control laws.The effects of relative measurement errors are also considered to validate the high accuracy of the proposed control method.
