The fuzzy integration evaluation method （FIEM） is studied in order to select the best orbital elements from the multi-group initial orbits determined by a satellite TT＆C （Tracking, Telemetry and Control） center w...The fuzzy integration evaluation method （FIEM） is studied in order to select the best orbital elements from the multi-group initial orbits determined by a satellite TT＆C （Tracking, Telemetry and Control） center with all kinds of data sources. By employing FIEM together with the experience of TT＆C experts, the index system to evaluate the selection of the best initial orbits is established after the data sources and orbit determination theories are studied. Besides, the concrete steps in employing the method are presented. Moreover, by taking the objects to be evaluated as evaluation experts, the problem of how to generate evaluation matrices is solved. Through practical application, the method to select the best initial orbital elements has been proved to be flexible and effective The originality of the method is to find a new evaluation criterion （comparing the actually tracked orbits） replacing the traditional one （comparing the nominal orbits） for selecting the best orbital elements.展开更多
An intrinsic extension of Pad′e approximation method, called the generalized Pad′e approximation method, is proposed based on the classic Pad′e approximation theorem. According to the proposed method, the numerator...An intrinsic extension of Pad′e approximation method, called the generalized Pad′e approximation method, is proposed based on the classic Pad′e approximation theorem. According to the proposed method, the numerator and denominator of Pad′e approximant are extended from polynomial functions to a series composed of any kind of function, which means that the generalized Pad′e approximant is not limited to some forms, but can be constructed in different forms in solving different problems. Thus, many existing modifications of Pad′e approximation method can be considered to be the special cases of the proposed method. For solving homoclinic and heteroclinic orbits of strongly nonlinear autonomous oscillators, two novel kinds of generalized Pad′e approximants are constructed. Then, some examples are given to show the validity of the present method. To show the accuracy of the method, all solutions obtained in this paper are compared with those of the Runge–Kutta method.展开更多
Purpose: To analyze and summarize the application of a turning implantation method in artificial orbital implantation. Methods:Artificial orbital implants were implanted into 46 patients who were willing to accept art...Purpose: To analyze and summarize the application of a turning implantation method in artificial orbital implantation. Methods:Artificial orbital implants were implanted into 46 patients who were willing to accept artificial orbital implantation with a turning implantation method. Results:After the implantation, 46 cases (46 eyes) with HA orbital implants were healed with plump orbits. No ptosis appearance, deformity, or rejection was observed. The implants were qualified in appearance and flexibility. Two cases presented with chemosis and eye grinding pain during the early postoperative period,but these patients recovered after effective treatment.After 6-24 months of follow-up,no patient had artificial implant exposure or abnormal orbital stimulation. Conclusion: The turning implantation method provides a good artificial orbital implantation.展开更多
The transcendental equation of a true anomaly was written in a power series instead of a differential form. When the sufficient condition of the iterative convergence is satisfied, the relationship between the true an...The transcendental equation of a true anomaly was written in a power series instead of a differential form. When the sufficient condition of the iterative convergence is satisfied, the relationship between the true anomaly and the time was gotten by the iterative method. And for the others, the transcendental equation of an eccentric anomaly was solved by the iterative method. After the eccentric anomaly had been calculated, the relationship between the true anomaly and the time was gotten with the numerical integral method. The approximate equation, which included the first five terms in general expansion, was written for the spacecraft quasi-circular orbit. And the true anomaly as the function of the time was also gotten by the iterative method. The numerical simulation results show that these methods are efficient.展开更多
This article analyzes the shift factors of the descending node local time for sun-synchronous satellites and proposes a shift control method to keep the local time shift within an allowance range. It is found that the...This article analyzes the shift factors of the descending node local time for sun-synchronous satellites and proposes a shift control method to keep the local time shift within an allowance range. It is found that the satellite orbit design and the orbit injection deviation are the causes for the initial shift velocity, whereas the atmospheric drag and the sun gravitational perturbation produce the shift acceleration. To deal with these shift factors, a shift control method is put forward, through such methods as orbit variation design, orbit altitude, and inclination keeping control. The simulation experiment and practical application have proved the effectiveness of this control method.展开更多
A new velocity determination algorithm with combination of remove and restore method, outliers detection method and Chebyshev fitting method with redundant observations is proposed. An optimal selection of number of s...A new velocity determination algorithm with combination of remove and restore method, outliers detection method and Chebyshev fitting method with redundant observations is proposed. An optimal selection of number of sampling points is given. The result shows that, when the number of sampling points is 19, the three-dimension （3D） interpolation precision of velocity is superior to 0.1 mm/s, which is above 3 times better than that of Chebyshev fitting method with redundant observations and far better than those of the conventional interpolation methods.展开更多
A model of electronic intersupplemental states was presented for calculating the d orbital energies of a distorted octahedral low spin ( S =1/2) n d 5(t 5 2, 2T 2)(n=3, 4, 5) multielectron system...A model of electronic intersupplemental states was presented for calculating the d orbital energies of a distorted octahedral low spin ( S =1/2) n d 5(t 5 2, 2T 2)(n=3, 4, 5) multielectron system, and the 6 dimensional eigenmatrices of two new types in real and complex orbital representations were derived from this electron model forth. In comparison with real and complex orbital methods offered by the hole model, the real and complex orbital methods reported in this paper not only could give directly all the electronic structure parameters for the n d 5(t 5 2, 2T 2) multielectron system, but also showed many other new advantages such as standardization in theory, systematization in method, agreement in calculation and so on.展开更多
Non-Hamiltonian systems containing degenerate fixed points obtained from twodegrees of freedom near-integrable Hamiltonian systems through non-canonicaltransformations are dealt with in this paper. Two criteria .for d...Non-Hamiltonian systems containing degenerate fixed points obtained from twodegrees of freedom near-integrable Hamiltonian systems through non-canonicaltransformations are dealt with in this paper. Two criteria .for determining theexistence of transversal homoclinic and heteroclinic orbits are presented. By exploitingthese criteria the existence of the transversal homoclinic orbits and so, of thetransversal homoclinic tangle .phenomenon in the near-integrable circular planarrestricted three-body problem with sufficiently small mass ratio of the two primaries isproven. Under some assumptions, the existence of the transversal heleroclinic orbits isproven. The global qualitative phase diagram is also illustrated.展开更多
The molecular geometries and electronic structures of 30 nitrobenzenes have been calculated by using semi-empirical MO AM1 and PM3 methods. EHOMO, ELUMO, ENHOMO, ENLUMO, AE, QNO2, Qc and V were selected as the structu...The molecular geometries and electronic structures of 30 nitrobenzenes have been calculated by using semi-empirical MO AM1 and PM3 methods. EHOMO, ELUMO, ENHOMO, ENLUMO, AE, QNO2, Qc and V were selected as the structural descriptors. The acute toxicity （-log/C50） of nitrobenzenes to tetrahymena pyriformis along with the above eight structural parameters was used to establish the quantitative structure-activity relationships （QSARs）. The results indicate that the established model based on AM I method is superior to that on PM3 method not only for the stability but also for the predictive powers of the model. Based on AM1 parameters, a further classifying discussion was presented for the study of nitrobenzene toxic mechanism. The results show that the substituents, nitro group and halogen substituents on the aromatic ring are crucial to the chemicals＇ toxicity. For nitrobenzenes without halogen or other substituent, the reduction of nitro group is the main route. However, for those with halogen substituents, their next lowest unoccupied molecular orbital may take part in the toxic action betweeen the chemicals and macromolecules, and ENLUMO has the most important effect on these chemicals＇ toxicity.展开更多
A basic calculation procedure for the MOSMO method under CNDO/2 approximation is presented in this paper,and performed by using the same parameters as those used in the ordinary CNDO/2 LCAO-MO calculation.The calculat...A basic calculation procedure for the MOSMO method under CNDO/2 approximation is presented in this paper,and performed by using the same parameters as those used in the ordinary CNDO/2 LCAO-MO calculation.The calculated results on the whole are close to those obtained by use of the ordinary CNDO/2 LCAO-MO calculation,illustrating that the presented procedure is reasonable.Due to its simplicity,the presented calculation procedure may be feasible even in very large molecular s ystems.展开更多
Satellite-to-Satellite tricking (SST) data can be used to determine the orbits of spacecraft in two ways. One is combined orbit determination, which combines SST data with ground-based tracking data and exploits the ...Satellite-to-Satellite tricking (SST) data can be used to determine the orbits of spacecraft in two ways. One is combined orbit determination, which combines SST data with ground-based tracking data and exploits the enhanced tracking geometry. The other is the autonomous orbit determination, which uses only SST. The latter only fits some particular circumstances since it suffers the rank defect problem in other circumstances. The proof of this statement is presented. The nature of the problem is also investigated in order to find an effective solution. Several. methods of solution are discussed. The feasibility of the methods is demonstrated by their application to a simulation.展开更多
Recently, the research of dynamics and control of the satellite formation flying has been attracting a great deal of attentions of the researchers. The theory of the research was mainly based on Clohessy-Wiltshire'...Recently, the research of dynamics and control of the satellite formation flying has been attracting a great deal of attentions of the researchers. The theory of the research was mainly based on Clohessy-Wiltshire' s (C-W's) equations, which describe the relative motion between two satellites. But according to some special examples and qualitative analysis , neither the initial parameters nor the period of the solution of C-W' s equations accord with the actual situation, and the conservation of energy is no longer held. A new method developed from orbital element description of single satellite , named relative orbital element method ( ROEM) , was introduced. This new method, with clear physics conception and wide application range, overcomes the limitation of C-W s equation , and the periodic solution is a natural conclusion. The simplified equation of the relative motion is obtained when the eccentricity of the main satellite is small. Finally, the results of the two methods (C-W' s equation and ROEM) are compared and the limitations of C-W s equations are pointed out and explained.展开更多
The homoclinic solutions problem of the Davey-Stewartson ( DS) Equations were studied. By using the Hirota's bilinear method, the homoclinic orbits of the Davey-Stewartson Equations were obtained through the depen...The homoclinic solutions problem of the Davey-Stewartson ( DS) Equations were studied. By using the Hirota's bilinear method, the homoclinic orbits of the Davey-Stewartson Equations were obtained through the dependent variable transformation. The homoclinic orbits of the Davey-Stewartson Equations were discussed.展开更多
It this paper we obtain existence and bifurcation theorems for homoclinic orbits in three-dimeensional,time dependent and independent,perturbations of generalized Hamiltonian differential equations defined on three-d...It this paper we obtain existence and bifurcation theorems for homoclinic orbits in three-dimeensional,time dependent and independent,perturbations of generalized Hamiltonian differential equations defined on three-dimensional Poisson manifolds.Thed we apply them to a truncated spectral model of the quasi-geostrophic flow on a cyclic β-plane.展开更多
In this paper, we design a novel three-order autonomous system. Numerical simulations reveal the complex chaotic behaviors of the system. By applying the undetermined coefficient method, we find a heteroclinic orbit i...In this paper, we design a novel three-order autonomous system. Numerical simulations reveal the complex chaotic behaviors of the system. By applying the undetermined coefficient method, we find a heteroclinic orbit in the system. As a result, the Si＇lnikov criterion along with some other given conditions guarantees that the system has both Smale horseshoes and chaos of horseshoe type.展开更多
基金This project was supported by the Evaluate Quality of Satellite TT&C Mission(C0112)
文摘The fuzzy integration evaluation method （FIEM） is studied in order to select the best orbital elements from the multi-group initial orbits determined by a satellite TT＆C （Tracking, Telemetry and Control） center with all kinds of data sources. By employing FIEM together with the experience of TT＆C experts, the index system to evaluate the selection of the best initial orbits is established after the data sources and orbit determination theories are studied. Besides, the concrete steps in employing the method are presented. Moreover, by taking the objects to be evaluated as evaluation experts, the problem of how to generate evaluation matrices is solved. Through practical application, the method to select the best initial orbital elements has been proved to be flexible and effective The originality of the method is to find a new evaluation criterion （comparing the actually tracked orbits） replacing the traditional one （comparing the nominal orbits） for selecting the best orbital elements.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11172093 and 11372102)the Hunan Provincial Innovation Foundation for Postgraduate,China(Grant No.CX2012B159)
文摘An intrinsic extension of Pad′e approximation method, called the generalized Pad′e approximation method, is proposed based on the classic Pad′e approximation theorem. According to the proposed method, the numerator and denominator of Pad′e approximant are extended from polynomial functions to a series composed of any kind of function, which means that the generalized Pad′e approximant is not limited to some forms, but can be constructed in different forms in solving different problems. Thus, many existing modifications of Pad′e approximation method can be considered to be the special cases of the proposed method. For solving homoclinic and heteroclinic orbits of strongly nonlinear autonomous oscillators, two novel kinds of generalized Pad′e approximants are constructed. Then, some examples are given to show the validity of the present method. To show the accuracy of the method, all solutions obtained in this paper are compared with those of the Runge–Kutta method.
文摘Purpose: To analyze and summarize the application of a turning implantation method in artificial orbital implantation. Methods:Artificial orbital implants were implanted into 46 patients who were willing to accept artificial orbital implantation with a turning implantation method. Results:After the implantation, 46 cases (46 eyes) with HA orbital implants were healed with plump orbits. No ptosis appearance, deformity, or rejection was observed. The implants were qualified in appearance and flexibility. Two cases presented with chemosis and eye grinding pain during the early postoperative period,but these patients recovered after effective treatment.After 6-24 months of follow-up,no patient had artificial implant exposure or abnormal orbital stimulation. Conclusion: The turning implantation method provides a good artificial orbital implantation.
文摘The transcendental equation of a true anomaly was written in a power series instead of a differential form. When the sufficient condition of the iterative convergence is satisfied, the relationship between the true anomaly and the time was gotten by the iterative method. And for the others, the transcendental equation of an eccentric anomaly was solved by the iterative method. After the eccentric anomaly had been calculated, the relationship between the true anomaly and the time was gotten with the numerical integral method. The approximate equation, which included the first five terms in general expansion, was written for the spacecraft quasi-circular orbit. And the true anomaly as the function of the time was also gotten by the iterative method. The numerical simulation results show that these methods are efficient.
基金supported by the China Postdotoral Science Foundation(20060401004)
文摘This article analyzes the shift factors of the descending node local time for sun-synchronous satellites and proposes a shift control method to keep the local time shift within an allowance range. It is found that the satellite orbit design and the orbit injection deviation are the causes for the initial shift velocity, whereas the atmospheric drag and the sun gravitational perturbation produce the shift acceleration. To deal with these shift factors, a shift control method is put forward, through such methods as orbit variation design, orbit altitude, and inclination keeping control. The simulation experiment and practical application have proved the effectiveness of this control method.
基金supported by the National Natural Science Foundation of China(41174008)the Open Foundation of State Key Laboratory of Geodesy and Earth’s Dynamics(SKLGED2013-4-2-EZ)the Foundation for the Author of National Excellent Doctoral Dissertation of China(2007B51)
文摘A new velocity determination algorithm with combination of remove and restore method, outliers detection method and Chebyshev fitting method with redundant observations is proposed. An optimal selection of number of sampling points is given. The result shows that, when the number of sampling points is 19, the three-dimension （3D） interpolation precision of velocity is superior to 0.1 mm/s, which is above 3 times better than that of Chebyshev fitting method with redundant observations and far better than those of the conventional interpolation methods.
文摘A model of electronic intersupplemental states was presented for calculating the d orbital energies of a distorted octahedral low spin ( S =1/2) n d 5(t 5 2, 2T 2)(n=3, 4, 5) multielectron system, and the 6 dimensional eigenmatrices of two new types in real and complex orbital representations were derived from this electron model forth. In comparison with real and complex orbital methods offered by the hole model, the real and complex orbital methods reported in this paper not only could give directly all the electronic structure parameters for the n d 5(t 5 2, 2T 2) multielectron system, but also showed many other new advantages such as standardization in theory, systematization in method, agreement in calculation and so on.
文摘Non-Hamiltonian systems containing degenerate fixed points obtained from twodegrees of freedom near-integrable Hamiltonian systems through non-canonicaltransformations are dealt with in this paper. Two criteria .for determining theexistence of transversal homoclinic and heteroclinic orbits are presented. By exploitingthese criteria the existence of the transversal homoclinic orbits and so, of thetransversal homoclinic tangle .phenomenon in the near-integrable circular planarrestricted three-body problem with sufficiently small mass ratio of the two primaries isproven. Under some assumptions, the existence of the transversal heleroclinic orbits isproven. The global qualitative phase diagram is also illustrated.
基金This work was supported by the National Natural Science Foundation of China (No.10576030)
文摘The molecular geometries and electronic structures of 30 nitrobenzenes have been calculated by using semi-empirical MO AM1 and PM3 methods. EHOMO, ELUMO, ENHOMO, ENLUMO, AE, QNO2, Qc and V were selected as the structural descriptors. The acute toxicity （-log/C50） of nitrobenzenes to tetrahymena pyriformis along with the above eight structural parameters was used to establish the quantitative structure-activity relationships （QSARs）. The results indicate that the established model based on AM I method is superior to that on PM3 method not only for the stability but also for the predictive powers of the model. Based on AM1 parameters, a further classifying discussion was presented for the study of nitrobenzene toxic mechanism. The results show that the substituents, nitro group and halogen substituents on the aromatic ring are crucial to the chemicals＇ toxicity. For nitrobenzenes without halogen or other substituent, the reduction of nitro group is the main route. However, for those with halogen substituents, their next lowest unoccupied molecular orbital may take part in the toxic action betweeen the chemicals and macromolecules, and ENLUMO has the most important effect on these chemicals＇ toxicity.
文摘A basic calculation procedure for the MOSMO method under CNDO/2 approximation is presented in this paper,and performed by using the same parameters as those used in the ordinary CNDO/2 LCAO-MO calculation.The calculated results on the whole are close to those obtained by use of the ordinary CNDO/2 LCAO-MO calculation,illustrating that the presented procedure is reasonable.Due to its simplicity,the presented calculation procedure may be feasible even in very large molecular s ystems.
文摘Satellite-to-Satellite tricking (SST) data can be used to determine the orbits of spacecraft in two ways. One is combined orbit determination, which combines SST data with ground-based tracking data and exploits the enhanced tracking geometry. The other is the autonomous orbit determination, which uses only SST. The latter only fits some particular circumstances since it suffers the rank defect problem in other circumstances. The proof of this statement is presented. The nature of the problem is also investigated in order to find an effective solution. Several. methods of solution are discussed. The feasibility of the methods is demonstrated by their application to a simulation.
基金Foundation items: the National Natural Science Foundation of China (10202008) the Post Doctoral Science Foundation of China ((2001)31)
文摘Recently, the research of dynamics and control of the satellite formation flying has been attracting a great deal of attentions of the researchers. The theory of the research was mainly based on Clohessy-Wiltshire' s (C-W's) equations, which describe the relative motion between two satellites. But according to some special examples and qualitative analysis , neither the initial parameters nor the period of the solution of C-W' s equations accord with the actual situation, and the conservation of energy is no longer held. A new method developed from orbital element description of single satellite , named relative orbital element method ( ROEM) , was introduced. This new method, with clear physics conception and wide application range, overcomes the limitation of C-W s equation , and the periodic solution is a natural conclusion. The simplified equation of the relative motion is obtained when the eccentricity of the main satellite is small. Finally, the results of the two methods (C-W' s equation and ROEM) are compared and the limitations of C-W s equations are pointed out and explained.
文摘The homoclinic solutions problem of the Davey-Stewartson ( DS) Equations were studied. By using the Hirota's bilinear method, the homoclinic orbits of the Davey-Stewartson Equations were obtained through the dependent variable transformation. The homoclinic orbits of the Davey-Stewartson Equations were discussed.
文摘It this paper we obtain existence and bifurcation theorems for homoclinic orbits in three-dimeensional,time dependent and independent,perturbations of generalized Hamiltonian differential equations defined on three-dimensional Poisson manifolds.Thed we apply them to a truncated spectral model of the quasi-geostrophic flow on a cyclic β-plane.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61170037 and 61074192)
文摘In this paper, we design a novel three-order autonomous system. Numerical simulations reveal the complex chaotic behaviors of the system. By applying the undetermined coefficient method, we find a heteroclinic orbit in the system. As a result, the Si＇lnikov criterion along with some other given conditions guarantees that the system has both Smale horseshoes and chaos of horseshoe type.
