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Equilibrium configurations of the tethered three-body formation system and their nonlinear dynamics

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Acta Mechanica Sinica 2012年第6期28卷 1668-1677页

作者： Ming Xu Jian-Min Zhu Tian Tan Shi-Jie Xu School of Astronautics Beihang University R&D Centre DFH Satellite Co. Ltd.

This paper considers nonlinear dynamics of teth- ered three-body formation system with their centre of mass staying on a circular orbit around the Earth, and applies the theory of space manifold dynamics to deal with the nonlinear dynamical behaviors of the equilibrium configurations of the system. Compared with the classical circular restricted three body system, sixteen equilibrium configurations are obtained globally from the geometry of pseudo-potential energy sur- face, four of which were omitted in the previous research. The periodic Lyapunov orbits and their invariant manifolds near the hyperbolic equilibria are presented, and an iteration procedure for identifying Lyapunov orbit is proposed based on the differential correction algorithm. The non-transversal intersections between invariant manifolds are addressed to generate homoclinic and heteroclinic trajectories between the Lyapunov orbits. （3,3）- and （2,1）-heteroclinic trajecto- ries from the neighborhood of one collinear equilibrium to that of another one, and （3,6）- and （2,1）-homoclinic trajecto- ries from and to the neighborhood of the same equilibrium, are obtained based on the Poincar6 mapping technique.

关键词： Tethered satellites system - Formation flying.Lyapunov orbit - Homoclinic/heteroclinic connection - Equi-librium configuration

Developing Prototype Simulants for Surface Materials and Morphology of Near Earth Asteroid 2016 HO3

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space(Science & Technology) 2021年第1期2021卷 50-55页

作者： Xiaojing Zhang Yuechen Luo Yuan Xiao Deyun Liu Fan Guo Qian Guo Qian Xuesen Laboratory of space Technology China Academy of Space TechnologyBeijing 100029China School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China Beijing spacecraft Manufacturing Factory Co. Ltd.Beijing 100094China Beijing Institute of space System Engineering Beijing 100094China Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

There are a variety of applications for asteroid simulants in asteroid studies for science advances as well as technology *** specific purpose,it usually requires purpose-specialized *** this study,we designed and developed a set of prototype simulants as S-type asteroid surface materials analogue based on H,L,and LL ordinary chondrites’mineralogy and terrestrial observations of near-earth asteroid 2016 HO3,which is the Chinese sample return mission *** simulants are able to simulate morphology and reflectance characteristics of asteroid(469219)2016 HO3 and,thus,to be used for engineering evaluation of the optical navigation system and the sampling device of the spacecraft during the mission ***,these prototype simulants are easily to modify to reflect new findings on the asteroid surface when the spacecraft makes proximate observations.

关键词： Earth terrestrial return

A New Multiple Gateway Transmit Diversity Technique for Future Satellite Networks

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China Communications 2022年第8期19卷 214-233页

作者： Xinhua Li Huibin Wang Wenbo Zhao Qiushi Tian Zehao Xu Bo Yang space Star Technology Co. LtdZhongguancun Environmental Science and Technology ParkHaidian DistrictBeijing 100095China China Academy of space Technology Beijing 100094China

The next generation of High Throughput Satellite(HTS)will exploit Q/V band for the feeder link and Ka band for the user *** exploitation of multiple gateways(GWs)is a transmit diversity measure to compensate severe rain attenuation of Q/V band feeder *** paper introduces a new smart gateway diversity combination scheme that combinates N-active(K=2)and N+1 diversity method in detail from the working principle,gateway switching strategy,evaluation of system availability and implementation *** addition,a feeder link outage event prediction algorithm featuring combination scheme is given detailly based on modified time-adaptive linear *** with the existing N+P scheme,the proposed scheme can provide higher system availability and more stable user’s experience under the condition of properly increasing the complexity of payload *** with Nactive scheme that has been reported,it is much easier to implement in engineering and more *** a result,the combination scheme is a realistic solution based on a trade-off between performance improvement and implementation complexity.

关键词： Q/V frequency band smart gateway diversity outage prediction gateway switching

Recent developments in nonferrous metals and related materials for biomedical applications in China:a review

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Rare Metals 2022年第5期41卷 1410-1433页

作者： Hai-Ling Tu Hong-Bin Zhao Yan-Yan Fan Qing-Zhu Zhang State Key Laboratory of Advanced Materials for Smart Sensing GRINM Group Co.Ltd.Beijing 100088China China Academy of space Technology Beijing 100094China Key Laboratory of Microelectronics Devices&Integrated Technology Institute of MicroelectronicsCASBeijing 100029China

Biomedical materials have received increasing attention in recent decades and have been used in medical applications to advance patient care,such as prosthetic implants,tissue repair and regeneration,drug delivery systems,pharmaceutical or biological therapy products,and sensitive diagnostic *** different types of biomedical materials,nonferrous metals and related materials(NMRMs)are important and attractive *** updating of biomedical NMRMs and devices heavily relies on original research and applicationoriented ***,we provide recent research findings and succinct insights into the developments in NMRMs for biomedical applications in China,including the use of titanium,magnesium,copper,zinc,cobalt,zirconium,hafnium,niobium,rhenium,tantalum,tungsten,silver,gold,platinum,palladium,their alloys and compounds,rare earths,high-entropy alloys,and liquid ***,the literature review concludes with several possible directions of NMRMs for new and future developments in biomedical engineering.

关键词： Nonferrous metal Biomedical Implants In vitro and in vivo Imaging Cancer treatment

Ground and flight tests of AlSat-1B butane propulsion system

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Propulsion and Power Research 2022年第1期11卷 74-84页

作者： D.Darfilala D.Gibbon Satellite Development Center CDS Algerian Space Agency ASALBP 4065Ibn Rochd USTOOran31130Algeria Surrey Satellite Technology ltd. GuildfordSurrey GU27YEUnited Kingdom

On September 26,2016 Algerian space Agency launched AlSat-1B,the second in a series of medium resolution earth observation satellites ***-1B electro-thermal propulsion system follows the classic design principle that has been used on previous SSTL-100 *** a total dry weight of 5.17 kg,the system is filled with 2.35 L selfpressurized *** thruster assembly is designed to use 15 W(at 28 V)redundant heater elements,it is designed to have an average mission thrust of 50 *** a warm up time of 10 min,the temperature of the butane will be increased by over 250℃.This is the equivalent of about 35%gain in specific impulse over ambient temperature *** spacecraft dry weigh at launch site was 107 kg,the propulsion system is designed to provide at least 19 m/s Delta-v to meet the spacecraft’s mission *** investigate the system readiness for flight,a series of performance tests have been completed at the Surrey Satellite Technology ltd.laboratories(United Kingdom),Satellite Development Centre(Algeria)and Satish Dhawan space Centre rocket launch site(India),the results of these tests as well as initial flight test results are presented in this paper.

关键词： space Propulsion Butane Resistojet Heaters Specific impulse

Diagnostics of Air-Breathing Electric Thrusters

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World Journal of Engineering and Technology 2015年第3期3卷 33-39页

作者： Constantinos Stavrinidis José Gonzalez del Amo Chloe Berenguer Konstantinos Katsonis ESTEC European Space Agency Noordwijk The Netherlands DEDALOS ltd. Thessaloniki Greece

Air-Breathing Electric Thrusters (ABET) diagnostics is addressed, with on-ground prototypes in mind. It is based on detailed volume averaged Global Models and focuses on emission spectroscopy. Notably, the obtained optical emission spectroscopy diagnostics tools give important information about the thruster propellant constitution and also the ionization degree of each constituent. This allows for trade-off between various prototypes on the basis of their characterization and optimization.

关键词： Diagnostics Low Earth Orbit Electric Thrusters Air-Breathing Spectroscopy

Atmospheric Remnants in the Low Earth Orbit Region around 200 km Altitude

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World Journal of Engineering and Technology 2015年第3期3卷 26-32页

作者： Konstantinos Katsonis Chloe Berenguer José Gonzalez del Amo Constantinos Stavrinidis DEDALOS ltd. Thessaloniki Greece ESTEC European Space Agency Noordwijk The Netherlands

Study of atmospheric remnants in the low Earth orbit region (~200 km altitude) using Global Models, with application to electric thrusters of in situ resources utilization type.

关键词： Atmospheric Composition Low Earth Orbit Air-Breathing Global Modeling

Pseudorange Bias Correction for BDSBAS Single Frequency Service

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Pseudorange Bias Correction for BDSBAS Single Frequency Serv...

Hydrocarbon accumulation conditions and key exploration and development technologies for PL 19-3 oilfield

第十三届中国卫星导航年会

作者： Liqian Zhao Biao Jin Qijia Dong Zixiao Li Ningning Liu space Star Technology Co. Ltd.

BDSBAS broadcasts SBAS corrections and integrity information via BDSBAS-B1 C signals of BeiDou-3 GEO satellites to improve the accuracy and integrity for GPS L1 CA single-frequency users in BDSBAS service area. However, if the GPS receiver type and technical status of BDSBAS reference station is quite different from the receiver of GPS ground operational control system and the BDSBAS receivers do not fully refer to the receivers of GPS ground operational control system to adjust the correlator spacing and front-end bandwidth, there will be inevitable relative pseudorange bias between the BDSBAS receivers and GPS ground operational control system receivers. Pseudorange bias is an important factor restricting the performance of BDSBAS singlefrequency service. This contribution analyzes the impact of GPS satellite pseudorange bias on the accuracy of BDSBAS single-frequency service, and then proposes a pseudorange bias correction method based on the Timing Group Delay（TGD） parameters, which can eliminate the impact of pseudorange bias on the GPS L1 CA SBAS positioning accuracy and improve the single-frequency service performance of BDSBAS. Six stations in the BDSBAS service area are used to carry out GPS L1 CA SBAS positioning experiment, the experiment results reveal that the average 95% positioning accuracy has a significant improvement after using the mentioned method to correct the pseudorange bias. The positioning errors are reduced from 1.70 m to 1.38 m and from 2.83 m to 2.29 m in the horizontal and vertical directions, respectively.

关键词： BDSBAS Reference Station Pseudorange Bias Timing Group Delay Service Performance

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Petroleum Research 2019年第1期4卷 29-51页

作者： Yong'an Xue Yunhua Deng Deying Wang Haifeng Yang Dingyou Lv Kai Kang Tianjin Branch Company China National Offshore Oil Co.Ltd.Tianjin300452China Research Institure Co.ltd China National Offshore Oil Co.Ltd.Beijing100028China

The PL 19e3 Oilfield is the only super-large monolithic oilfield with oil and gas reserves up to 1×10^(9) t in the Bohai Bay Basin,and it has been successfully *** and development practices have provided abundant data for analyzing formation conditions of this super-large *** the basis of the exploration and development history,fundamental reservoir features,and with available geological,geophysical and test data,the hydrocarbon accumulation conditions and key exploration&development technologies of the PL 19e3 Oilfield were *** key conditions for forming the super-large Neogene oilfield include four ***,the oilfield is located at the high position of the uplift that contacts the brachy-axis of the multi-ridge slope in the biggest hydrocarbon-rich sag in the Bohai Bay Basin,thus it has sufficient hydrocarbon source and extremely superior hydrocarbon migration ***,the large-scale torsional anticlines which formed in the Neogene under the control of the Tanlu strike-slipping movement provide sufficient storage spaces for oil and gas ***,the“multiple sets of composite reservoir-caprock assemblages”developing in the special shallow-water delta further contributes greatly to the effective storage space for oil and gas ***,due to the coupling of the uplift and strike slip in the neotectonic period,extensive faulting activities constantly released the pressure while the late period massive hydrocarbon expulsion of the Bozhong took place at the same time,which assures the constant and intense charging of oil and *** super-large PL 19e3 Oilfield was controlled by the coupling effects of all those special geologic *** view of this oilfield's features(*** reformation caused by strike slip,and the special sedimentary environment of shallow-water delta),some key practical technologies for exploration and development have been *** technologies include:

关键词： PL 19e3 Hydrocarbon accumulation conditions Multiple composite reservoir-caprock assemblages Constant and intense charging of oil and gas during later period Gas cloud zone Exploration and development technology