This paper proposes an electromagnetic coil topology and its control strategy,which can be incorporated into the electromagnetic docking device to achieve relative pose control in satellite docking.The target satellit...This paper proposes an electromagnetic coil topology and its control strategy,which can be incorporated into the electromagnetic docking device to achieve relative pose control in satellite docking.The target satellite has a main coil;the chaser satellite possesses a main coil of the same size accompanied by six and four evenly arranged secondary coils inside and outside the main coil,respectively.The coil on the target satellite is DC energized,while the currents in the coils of the chaser satellite are regulated.To remove the coupling between the pitch/yaw torque and translational force,the internal and external secondary coils of the chaser satellite interact with the main coil of the target satellite to perform the control of relative pitch/yaw and relative translation,respectively,so relative pose control can be achieved.The torque and force vectors exerted by the secondary coils of the chaser satellite are synthesized onto the pitch and yaw axes of the body frame.According to their spatial composition relationship,the formulas are proposed,which obtain the magnetic moment vectors of the coils from the set torques and forces.The controllers regulating pitch/yaw,translation,and distance utilize a three-loop cascaded structure that consists of an outer position loop,a middle velocity loop and an inner current loop.The control strategy is verified by dynamics simulation.展开更多
In the paper,with the help of the Fa′a di Bruno formula and an identity of the Bell polynomials of the second kind,the authors define degenerateλ-array type polynomials,establish two explicit formulas,and present se...In the paper,with the help of the Fa′a di Bruno formula and an identity of the Bell polynomials of the second kind,the authors define degenerateλ-array type polynomials,establish two explicit formulas,and present several recurrence relations of degenerateλ-array type polynomials and numbers.展开更多
An electromagnetic coil topology and its control strategy,which can be incorporated into the electromagnetic docking device,have been proposed for the relative roll control of two satellites in space.The target satell...An electromagnetic coil topology and its control strategy,which can be incorporated into the electromagnetic docking device,have been proposed for the relative roll control of two satellites in space.The target satellite and the chaser satellite are respectively embarked with four and six coils evenly arranged around the docking axis.All the coils on the target satellite are Direct Current(DC)energized,while the currents in the coils of the chaser satellite are regulated to achieve the relative roll control.The electromagnetic force/torque model is built by utilizing the frequentlyused far field model.Based on the fundamental components extracted from that model,this paper proposes a real-time magnetic moment vector distribution formula that simply generates a constant roll torque.This paper not only presents an equation for calculating the relative roll angle through the Euler angles of two satellites,but also an equation that converts the roll torque setpoint to the setpoints of the coil currents.A 3-closed-loop positioning controller composed of angle,angular velocity,and current loop is developed.The proposed topology is verified by finite element simulation,and the control strategy is validated by dynamics simulation and ground-based tests.展开更多
The Delta4 3D dose verification device was commissioned in the current work for pre-treatment quality assurance (QA) of Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) plans. The cr...The Delta4 3D dose verification device was commissioned in the current work for pre-treatment quality assurance (QA) of Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) plans. The cross calibration and relative array calibration were performed to enable absolute dose comparison. The linearity of response with dose and temperature sensitivity tests were also conducted to investigate dosimetric properties of the Delta4 device. The need to modify the original CT image of the Delta4 phantom for accurate dose calculation and comparison is addressed in this work, applying a CT extension algorithm. A number of test plans varying from simple 4—field conformal to IMRT and VMAT plans were measured to evaluate the accuracy of this device. It was found that the Delta4 device measured dose accurately to within ±1%. In order to maintain this level of accuracy the machine output fluctuations need to be corrected prior to each measurement and the relative array calibration needs to be performed every six months.展开更多
The contents of indapamide and related impurities in generic indapamide sustained-release tablets were simultaneously detected by a single-run high performance liquid chromatography equipped with photodiode array dete...The contents of indapamide and related impurities in generic indapamide sustained-release tablets were simultaneously detected by a single-run high performance liquid chromatography equipped with photodiode array detector(HPLC-PDA)method for the quality control in this paper.The results showed the method had a good selectivity and was validated through linearity,limits of detection and quantification,recovery,and precision.The linear ranges of indapamide,2-methyl-1-nitroso-2,3-dihydro-1H-indole(impurity A,ImA),4-chloro-N-(2-methyl-1H-indol-1-yl)-3-sulphamoyl-benzamide(impurity B,ImB)and 4-chloro-3-sulfamoylbenzoic acid(impurity 1,Im1)were 0.028-1.80μg/mL(R=0.99995),0.060-1.20μg/mL(R=0.9996),0.0324-1.20μg/mL(R=0.99985)and 0.060-1.20μg/mL(R=0.9997)with detection limits of 0.0093,0.012,0.012 and 0.006μg/mL,respectively.ImA and Im1 were not detectable in the generic drug.The content of indapamide was 96.7%of the labeled amount with a relative standard deviation(RSD)of 1.30%,and the percentage of ImB relative to the labeled amounts of indapamide was 0.106%with an RSD of 1.82%.The content of other unspecified impurities all met the reference quality standards.The results provided references for the quality control and the quality standard study of generic indapamide sustained-release tablets.展开更多
The upcoming Square Kilometre Array (SKA) radio telescope will become the largest astronomical observation facility,and is expected to introduce revolutionary changes in major fields of natural sciences.These revoluti...The upcoming Square Kilometre Array (SKA) radio telescope will become the largest astronomical observation facility,and is expected to introduce revolutionary changes in major fields of natural sciences.These revolutionary changes help us to answer the fundamental questions related to the origins of the universe,life,cosmic magnetic field,the nature of gravity,and to search for extraterrestrial civilizations [1].展开更多
Loop pairing is one of the major concerns when designing decentralized control systems for multivariable processes.Most existing pairing tools,such as the relative gain array(RGA) method,have shortcomings both in meas...Loop pairing is one of the major concerns when designing decentralized control systems for multivariable processes.Most existing pairing tools,such as the relative gain array(RGA) method,have shortcomings both in measuring interaction and in integrity issues.To evaluate the overall interaction among loops,we propose a statistics-based criterion via enumerating all possible combinations of loop statuses.Furthermore,we quantify the traditional concept of integrity to represent the extent of integrity of a decentralized control system.Thus,we propose that a pairing decision should be made by taking both factors into consideration.Two examples are provided to illustrate the effectiveness of the proposed criterion.展开更多
基金the Beijing Institute of Spacecraft System Engineering for providing topics,putting forward requirements and granting project funding。
文摘This paper proposes an electromagnetic coil topology and its control strategy,which can be incorporated into the electromagnetic docking device to achieve relative pose control in satellite docking.The target satellite has a main coil;the chaser satellite possesses a main coil of the same size accompanied by six and four evenly arranged secondary coils inside and outside the main coil,respectively.The coil on the target satellite is DC energized,while the currents in the coils of the chaser satellite are regulated.To remove the coupling between the pitch/yaw torque and translational force,the internal and external secondary coils of the chaser satellite interact with the main coil of the target satellite to perform the control of relative pitch/yaw and relative translation,respectively,so relative pose control can be achieved.The torque and force vectors exerted by the secondary coils of the chaser satellite are synthesized onto the pitch and yaw axes of the body frame.According to their spatial composition relationship,the formulas are proposed,which obtain the magnetic moment vectors of the coils from the set torques and forces.The controllers regulating pitch/yaw,translation,and distance utilize a three-loop cascaded structure that consists of an outer position loop,a middle velocity loop and an inner current loop.The control strategy is verified by dynamics simulation.
基金The first two authors,Mrs.Lan Wu and Xue-Yan Chen,were partially supported by the College Scientific Research Project of Inner Mongolia(Grant No.NJZY19156 and Grant No.NJZZ19144)by the Natural Science Foundation Project of Inner Mongolia(Grant No.2021LHMS05030)by the Development Plan for Young Technological Talents in Colleges and Universities of Inner Mongolia(Grant No.NJYT22051)in China.
文摘In the paper,with the help of the Fa′a di Bruno formula and an identity of the Bell polynomials of the second kind,the authors define degenerateλ-array type polynomials,establish two explicit formulas,and present several recurrence relations of degenerateλ-array type polynomials and numbers.
基金the Beijing Institute of Spacecraft System Engineering for providing topics,putting forward requirements and granting project funding。
文摘An electromagnetic coil topology and its control strategy,which can be incorporated into the electromagnetic docking device,have been proposed for the relative roll control of two satellites in space.The target satellite and the chaser satellite are respectively embarked with four and six coils evenly arranged around the docking axis.All the coils on the target satellite are Direct Current(DC)energized,while the currents in the coils of the chaser satellite are regulated to achieve the relative roll control.The electromagnetic force/torque model is built by utilizing the frequentlyused far field model.Based on the fundamental components extracted from that model,this paper proposes a real-time magnetic moment vector distribution formula that simply generates a constant roll torque.This paper not only presents an equation for calculating the relative roll angle through the Euler angles of two satellites,but also an equation that converts the roll torque setpoint to the setpoints of the coil currents.A 3-closed-loop positioning controller composed of angle,angular velocity,and current loop is developed.The proposed topology is verified by finite element simulation,and the control strategy is validated by dynamics simulation and ground-based tests.
文摘The Delta4 3D dose verification device was commissioned in the current work for pre-treatment quality assurance (QA) of Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) plans. The cross calibration and relative array calibration were performed to enable absolute dose comparison. The linearity of response with dose and temperature sensitivity tests were also conducted to investigate dosimetric properties of the Delta4 device. The need to modify the original CT image of the Delta4 phantom for accurate dose calculation and comparison is addressed in this work, applying a CT extension algorithm. A number of test plans varying from simple 4—field conformal to IMRT and VMAT plans were measured to evaluate the accuracy of this device. It was found that the Delta4 device measured dose accurately to within ±1%. In order to maintain this level of accuracy the machine output fluctuations need to be corrected prior to each measurement and the relative array calibration needs to be performed every six months.
基金the Natural Science Foundation of Anhui Province,China(11040606M41)the Natural Science Project in Colleges and Universities of Anhui Province,China(kj2016A683)the Natural Science Project of Huangshan University,China(hxkt20190042,xdhz202007)。
文摘The contents of indapamide and related impurities in generic indapamide sustained-release tablets were simultaneously detected by a single-run high performance liquid chromatography equipped with photodiode array detector(HPLC-PDA)method for the quality control in this paper.The results showed the method had a good selectivity and was validated through linearity,limits of detection and quantification,recovery,and precision.The linear ranges of indapamide,2-methyl-1-nitroso-2,3-dihydro-1H-indole(impurity A,ImA),4-chloro-N-(2-methyl-1H-indol-1-yl)-3-sulphamoyl-benzamide(impurity B,ImB)and 4-chloro-3-sulfamoylbenzoic acid(impurity 1,Im1)were 0.028-1.80μg/mL(R=0.99995),0.060-1.20μg/mL(R=0.9996),0.0324-1.20μg/mL(R=0.99985)and 0.060-1.20μg/mL(R=0.9997)with detection limits of 0.0093,0.012,0.012 and 0.006μg/mL,respectively.ImA and Im1 were not detectable in the generic drug.The content of indapamide was 96.7%of the labeled amount with a relative standard deviation(RSD)of 1.30%,and the percentage of ImB relative to the labeled amounts of indapamide was 0.106%with an RSD of 1.82%.The content of other unspecified impurities all met the reference quality standards.The results provided references for the quality control and the quality standard study of generic indapamide sustained-release tablets.
基金supported by the National Key R&D Program of China(Grant No.2018YFA0404600)the International Cooperation Bureau of the Chinese Academy of Sciences(Grant No.114231KYSB20170003)
文摘The upcoming Square Kilometre Array (SKA) radio telescope will become the largest astronomical observation facility,and is expected to introduce revolutionary changes in major fields of natural sciences.These revolutionary changes help us to answer the fundamental questions related to the origins of the universe,life,cosmic magnetic field,the nature of gravity,and to search for extraterrestrial civilizations [1].
基金supported by the National High-Tech Research and Development Program (863) of China (No.2009AA04Z154)the National Natural Science Foundation of China (No.60736021)
文摘Loop pairing is one of the major concerns when designing decentralized control systems for multivariable processes.Most existing pairing tools,such as the relative gain array(RGA) method,have shortcomings both in measuring interaction and in integrity issues.To evaluate the overall interaction among loops,we propose a statistics-based criterion via enumerating all possible combinations of loop statuses.Furthermore,we quantify the traditional concept of integrity to represent the extent of integrity of a decentralized control system.Thus,we propose that a pairing decision should be made by taking both factors into consideration.Two examples are provided to illustrate the effectiveness of the proposed criterion.