The algorithm of using one-day-arc to integrate n-days-arc by orbit overlaying is discussed in detail. An example is given, which proves that the orbit integration method can improve the precision of the orbit efficie...The algorithm of using one-day-arc to integrate n-days-arc by orbit overlaying is discussed in detail. An example is given, which proves that the orbit integration method can improve the precision of the orbit efficiently, especially in the determination of a local area＇s orbit.展开更多
This paper focuses mainly on the major errors and their reduction approaches pertaining to combined GPS/GLONASS positioning.To determine the difference in the time reference systems,different receiver clock offsets ar...This paper focuses mainly on the major errors and their reduction approaches pertaining to combined GPS/GLONASS positioning.To determine the difference in the time reference systems,different receiver clock offsets are introduced with respect to GPS and GLONASS system time.A more desirable method for introducing a independent unknown parameter of fifth receiver,which can be canceled out when forming difference measurements,is discussed.The error of orbit integration and the error of transformation parameters are addressed in detail.Results of numerical integration are given.To deal with the influence of ionospheric delay,a method for forming dual_frequency ionospheric free carrier phase measurements is detailed.展开更多
The rate constants of the nucleophilic reactions between amines and benzhydrylium ions were calculated using first-principles theoretical methods. Solvation models including PCM, CPCM, and COSMORS, as well as differen...The rate constants of the nucleophilic reactions between amines and benzhydrylium ions were calculated using first-principles theoretical methods. Solvation models including PCM, CPCM, and COSMORS, as well as different types of atomic radii including UA0, UAKS, UAHF, Bondi, and UFF, and several single-point energy calculation methods （B3LYP, B3P86, B3PW91, BHANDH, PBEPBE, BMK, M06, MP2, and ONIOM method） were examined. By comparing the correlation between experimental rate constants and the calculated values, the ONIOM（CCSD（T）/6-311＋＋G（2df,2p）：B3LYP/6-311＋＋G（2df,2p））//B3LYP/6- 31G（d）/PCM/UFF） method was found to perform the best. This method was then employed to calculate the rate constants of the reactions between diverse amines and diarylcarbenium ions. The calculated rate constants for 65 reactions of amines with diarylcarbenium ions are in agreement with the experimental values, indicating that it is feasible to predict the rate constant of a reaction between an amine and a diarylcarbenium ion through ab initio calculation.展开更多
A linear response function for zonal flows is obtained by solving the gyro-kinetic equation. This is an extension of a previous work which adopted the method of ＂integrating along particle orbit＂ to solve the drift ...A linear response function for zonal flows is obtained by solving the gyro-kinetic equation. This is an extension of a previous work which adopted the method of ＂integrating along particle orbit＂ to solve the drift kinetic equation. The formula derived in this paper is used to calculate the dispersion relation of geodesic acoustic mode, which is then compared with that of the gyro-kinetic analytic formula.展开更多
The inner-formation gravity field measurement satellite （IFS） is a novel pure gravitational orbiter. It aims to measure the Earth＇s gravity field with unprecedented accuracy and spatial resolution by means of preci...The inner-formation gravity field measurement satellite （IFS） is a novel pure gravitational orbiter. It aims to measure the Earth＇s gravity field with unprecedented accuracy and spatial resolution by means of precise orbit determination （POD） and relative state measurement. One of the key factors determining the measurement level is the outer-satellite control used for keeping the inner-satellite flying in a pure gravitational orbit stably. In this paper the integrated orbit and attitude control of IFS during steady-state phase was investigated using only thrusters. A six degree-of-freedom translational and rotational dynamics model was constructed considering nonlinearity resulted from quaternion expression and coupling induced by community thrusters. A feasible quadratic optimization model was established for the integrated orbit and attitude control using con- strained nonlinear model predictive control （CNMPC） techniques. Simulation experiment demonstrated that the presented CNMPC aigorithm can achieve rapid calculation and overcome the non-convexity of partial constraints. The thruster layout is rational with low thrust consumption, and the mission requirements of IFS are fully satisfied.展开更多
Considering the characteristic orbit of Shenzhou IV spacecraft and the advantages and disadvantages of several types of domestic orbit measurements, a scheme of IPOD is determined, which uses GPS, SLR and USB observat...Considering the characteristic orbit of Shenzhou IV spacecraft and the advantages and disadvantages of several types of domestic orbit measurements, a scheme of IPOD is determined, which uses GPS, SLR and USB observation data jointly plus precise ionosphere corrections to GPS observation data. IPOD system and mathematic models of OD are introduced. The results of different joint OD are analyzed using true observation data, and show that radial accuracy is better than 2 m.展开更多
Let W be a real symplectic space and(G,G')an irreducible dual pair in Sp(W),in the sense of Howe,with G compact.Let G be the preimage of G in the metaplectic group Sp(W).Given an irreducible unitary representation...Let W be a real symplectic space and(G,G')an irreducible dual pair in Sp(W),in the sense of Howe,with G compact.Let G be the preimage of G in the metaplectic group Sp(W).Given an irreducible unitary representation II of G that occurs in the restriction of the Weil representation to G,let On denote its character.We prove that,for a suitable embedding T of Sp(W)in the space of tempered distributions on W,the distribution T(On)admits an asymptotic limit,and the limit is a nilpotent orbital integral.As an application,we compute the wave front set of II',the representation of G dual to II,by elementary means.展开更多
基金Supported by the National 863 Program of China （No.2006AA12Z323）, the National 973 Program of China （No.2006CB701301）, the National Natural Science Foundation of China （No.40774008） and the Open Research Fund Program of Key Laboratory of Geospace Environment and Geodesy, Ministry of Education, China （No.06-10）.
文摘The algorithm of using one-day-arc to integrate n-days-arc by orbit overlaying is discussed in detail. An example is given, which proves that the orbit integration method can improve the precision of the orbit efficiently, especially in the determination of a local area＇s orbit.
文摘This paper focuses mainly on the major errors and their reduction approaches pertaining to combined GPS/GLONASS positioning.To determine the difference in the time reference systems,different receiver clock offsets are introduced with respect to GPS and GLONASS system time.A more desirable method for introducing a independent unknown parameter of fifth receiver,which can be canceled out when forming difference measurements,is discussed.The error of orbit integration and the error of transformation parameters are addressed in detail.Results of numerical integration are given.To deal with the influence of ionospheric delay,a method for forming dual_frequency ionospheric free carrier phase measurements is detailed.
文摘The rate constants of the nucleophilic reactions between amines and benzhydrylium ions were calculated using first-principles theoretical methods. Solvation models including PCM, CPCM, and COSMORS, as well as different types of atomic radii including UA0, UAKS, UAHF, Bondi, and UFF, and several single-point energy calculation methods （B3LYP, B3P86, B3PW91, BHANDH, PBEPBE, BMK, M06, MP2, and ONIOM method） were examined. By comparing the correlation between experimental rate constants and the calculated values, the ONIOM（CCSD（T）/6-311＋＋G（2df,2p）：B3LYP/6-311＋＋G（2df,2p））//B3LYP/6- 31G（d）/PCM/UFF） method was found to perform the best. This method was then employed to calculate the rate constants of the reactions between diverse amines and diarylcarbenium ions. The calculated rate constants for 65 reactions of amines with diarylcarbenium ions are in agreement with the experimental values, indicating that it is feasible to predict the rate constant of a reaction between an amine and a diarylcarbenium ion through ab initio calculation.
基金partially supported by the JSPS-CAS Core-University program in the field of 'Plasma and Nuclear Fusion'
文摘A linear response function for zonal flows is obtained by solving the gyro-kinetic equation. This is an extension of a previous work which adopted the method of ＂integrating along particle orbit＂ to solve the drift kinetic equation. The formula derived in this paper is used to calculate the dispersion relation of geodesic acoustic mode, which is then compared with that of the gyro-kinetic analytic formula.
基金supported by the National Natural Science Foundation of China (Grant No. 11002076)the National Defense Pre-Research (Grant No.51320010201)
文摘The inner-formation gravity field measurement satellite （IFS） is a novel pure gravitational orbiter. It aims to measure the Earth＇s gravity field with unprecedented accuracy and spatial resolution by means of precise orbit determination （POD） and relative state measurement. One of the key factors determining the measurement level is the outer-satellite control used for keeping the inner-satellite flying in a pure gravitational orbit stably. In this paper the integrated orbit and attitude control of IFS during steady-state phase was investigated using only thrusters. A six degree-of-freedom translational and rotational dynamics model was constructed considering nonlinearity resulted from quaternion expression and coupling induced by community thrusters. A feasible quadratic optimization model was established for the integrated orbit and attitude control using con- strained nonlinear model predictive control （CNMPC） techniques. Simulation experiment demonstrated that the presented CNMPC aigorithm can achieve rapid calculation and overcome the non-convexity of partial constraints. The thruster layout is rational with low thrust consumption, and the mission requirements of IFS are fully satisfied.
文摘Considering the characteristic orbit of Shenzhou IV spacecraft and the advantages and disadvantages of several types of domestic orbit measurements, a scheme of IPOD is determined, which uses GPS, SLR and USB observation data jointly plus precise ionosphere corrections to GPS observation data. IPOD system and mathematic models of OD are introduced. The results of different joint OD are analyzed using true observation data, and show that radial accuracy is better than 2 m.
基金the University of Oklahoma for hospitality and financial supporthospitality and financial support from the Université de Lorraine+1 种基金partial support from NSA (Grant No. H98230-13-1-0205)NSF (Grant No. DMS-2225892)
文摘Let W be a real symplectic space and(G,G')an irreducible dual pair in Sp(W),in the sense of Howe,with G compact.Let G be the preimage of G in the metaplectic group Sp(W).Given an irreducible unitary representation II of G that occurs in the restriction of the Weil representation to G,let On denote its character.We prove that,for a suitable embedding T of Sp(W)in the space of tempered distributions on W,the distribution T(On)admits an asymptotic limit,and the limit is a nilpotent orbital integral.As an application,we compute the wave front set of II',the representation of G dual to II,by elementary means.
