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Science china(Physics,Mechanics & Astronomy) 2010年第12期53卷 2300-2306页

作者： CAI ChengLin 1,3 , LI XiaoHui 2,3 & WU HaiTao 2,3 1 Gulin University of Electronic technology, 541004, china 2 National Time service center, Chinese Academy of Sciences, Lintong 710600, china 3 Key Laboratory of Precision Navigation and Timing technology, National Time service center, Chinese Academy of Sciences, Lintong 710600, china 1. Gulin University of Electronic technology Gulin 541004 China3. Key Laboratory of Precision Navigation and Timing Technology National Time Service Center Chinese Academy of Sciences Lintong 710600 China2. National Time Service Center Chinese Academy of Sciences Lintong 710600 China

In order to solve the problems that the novel wide area differential method on the satellite clock and ephemeris relative correction (CERC) in the non-geostationary orbit satellite constellation, a virtual reference satellite (VRS) differential principle using relative correction of satellite ephemeris errors is proposed. It is referred to be as the VRS differential principle, and the elaboration is focused on the construction of pseudo-range errors of VRS. Through qualitative analysis, it can be found that the impact of the satellite’s clock and ephemeris errors on positioning can basically be removed and the users’ positioning errors are near zero. Through simulation analysis of the differential performance, it is verified that the differential method is universal in all kinds of satellite navigation systems with geostationary orbit (GEO) constellation, Medium orbit (MEO) constellation or hybrid orbit constellation, and it has insensitivity to abnormal aspects of a satellite ephemeris and clock. Moreover, the real time positioning accuracy of differential users can be maintained within several decimeters after the pseudo-range measurement noise is effectively weakened or eliminated.

关键词： wide area differential method virtual reference satellite (VRS) satellite ephemeris errors satellite clock errors constellation

An analysis of the wide area differential method of geostationary orbit satellites

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Science china(Physics,Mechanics & Astronomy) 2009年第2期52卷 310-314页

作者： CAI ChengLin1,2,3?, LI XiaoHui1 & WU HaiTao1 1 National Time service center, Chinese Academy of Sciences, Lintong 710600, china 2 Hunan Institute of Humanities, Science and technology, Loudi 417000, china 3 Graduate University of Chinese Academy of Sciences, Beijing 100049, china 1. National Time service center Chinese Academy of Sciences Lintong 710600 China 2. Hunan Institute of Humanities Science and Technology Loudi 417000 China 3. Graduate University of Chinese Academy of Sciences Beijing 100049 China

This work aims to obtain a wide area differential method for geostationary orbit (GEO) constellation. A comparison between the dilution of precision (DOP) of four-dimensional (4D) calculation including sa- tellite clock errors and ephemeris errors and that of three-dimensional (3D) calculation only including ephemeris errors with the inverse positioning theory of GPS shows the conclusion that all the 3D PDOPs are greatly reduced. Based on this, a basic idea of correcting satellite clock errors and ephem- eris errors apart is put forward, and moreover, a specific method of separation is proposed. Satellite clock errors are separated in a master station with time synchronization, and all the remaining pseu- do-range errors after the satellite clock errors have been deducted are used to work out ephemeris corrections of all GEO satellites. By a comparative analysis of user positioning accuracy before and after differential, the wide area differential method is verified to be quite valid for GEO constellation.

关键词： geostationary orbitsatellite dilution of precision satellite ephemeris errors satellite clock errors wide area differential method

SIMULATION STUDY OF GENERALIZED MINIMUM VARIANCE CONTROL FOR AN EXTRACTION TURBINE

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Chinese Journal of Mechanical Engineering 2003年第4期16卷 424-427,444页

作者： Shi XiaopingSimulation center,Harbin Institute of technology,Harbin 150001, china Simulation center Harbin Institute of Technology Harbin 150001 China

In an extraction turbine, pressure of the extracted steam and rotate speed of the rotor are two important controlled quantities. The traditional linear state feedback control method is not perfect enough to control the two quantities accurately because of existence of nonlinearity and coupling. A generalized minimum variance control method is studied for an extraction turbine. Firstly, a nonlinear mathematical model of the control system about the two quantities is transformed into a linear system with two white noises. Secondly, a generalized minimum variance control law is applied to the system. A comparative simulation is done. The simulation results indicate that precision and dynamic quality of the regulating system under the new control law are both better than those under the state feedback control law.

关键词： Extraction turbine Rotate speed Generalized minimum variance control Simulation

Friction behavior of coupling motion for natural articular cartilage by reciprocating rotation

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Chinese Science Bulletin 2009年第4期54卷 576-583页

作者： QIAN ShanHua1,2,3 & GE ShiRong1,3 1 College of Mechano-electronic Engineering, china University of Mining & technology, Xuzhou 221116, china 2 Institute of Tribology and Reliability Engineering, china University of Mining & technology, Xuzhou 221116, china 3 Biotribology center, State Key Laboratory of Tribology, Xuzhou 221116, china College of Mechano-electronic Engineering China University of Mining & Technology Xuzhou 221116 China Institute of Tribology and Reliability Engineering China University of Mining & Technology Xuzhou 221116 China Biotribology center State Key Laboratory of Tribology Xuzhou 221116 China

Based on the irregular surface of natural cartilage configurations, the tribological characteristics of coupling motion between natural cartilage pairs were investigated by the variation of rotated offset and velocity. Contact displacement, contact load, friction force and coefficient of friction from natural cartilage pairs were measured by a UMT-2 testing machine. In order to obtain the steady part and wavy part, the contact load and contact displacement were decompounded by the five-point sliding average method. These results showed that the contact load was composed of steady load and wavy load. And the contact displacement was composed of cartilage deformation and surface outline. The steady load was similar to exterior load while natural cartilage deformation increased nonlinearly with the sliding time. Wavy load had the correlative coefficient 0.235 with surface outline due to the irregular surface of friction configurations. The coefficient of friction from cartilage friction configurations was less influenced by smaller magnitude in rotated parameters. A few strange summits were obtained in the area of coef-ficient of friction, and significantly related with local minimal values corresponding to the contact loads. The rotated offsets had clear impact on contact load and a slight impact on contact displacement. Larger offset produced higher wavy magnitude of the contact load. The rotated velocities played an evident role in cartilage deformation, but had a less influence on contact load. Lower velocity brought larger cartilage deformation.

关键词：软骨构造关节软骨摩擦系数软骨变形接触装

Adsorption of surfactants onto acrylic ester resins with different pore size distribution

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Science china Chemistry 2006年第5期49卷 445-453页

作者： YANG Weiben1,2,3,LI Aimin1,3,CAI Jianguo1,3,MENG Guanhua1,3 & ZHANG Quanxing1,3 1. State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing 210093,china 2. Nanjing College of Chemical technology,Nanjing 210048,china 3. Jiangsu Engineering & technology Research center for Organic Toxicant Control and Resource Reuse,Nanjing 210038,china 1. State Key Laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanjing 210093 China 2. Nanjing College of Chemical technology Nanjing 210048 China 3. Jiangsu Engineering & technology Research center for Organic Toxicant Control and Resource Reuse Nanjing 210038 China

In this study, a series of acrylic ester resins with different pore size distribution were prepared successfully by varying the type and the amount of pore-forming agents. In order to inves-tigate the adsorption behavior and mechanism of surfactants on acrylic ester resins, three kinds of surfactants were utilized as adsorbates that were sodium 6-dodecyl benzenesulfonate (6-NaDBS), sodium 1-dodecyl benzene sulfonate (1-NaDBS) and sodium 1-dodecyl sulfonate, respectively. It was observed that the surface area was available in a particular pore size and an appropriate pore size of resins appeared to be more important for the adsorption of surfactants. As compared to commercial acrylic ester resins XAD-7 and HP2MG, 50# and 38# resins exhibited more excellent adsorption properties toward 1-NaDBS and 6-NaDBS. The experimental equilibrium data were fitted to the Langmuir, and double-Langmuir models. Two models provided very good fittings for all resins over the temperature range studied. The investigation indicated that electrostatic attraction and hydrogen bond between resins and surfactants were the main forces and had an obvious effect on adsorption proc-ess.

关键词： acrylic ester resin, surfactant, adsorption, pore size distribution, isotherm.

Association between ICU quality and in-hospital mortality of V-V ECMO-supported patients—the ECMO quality improvement action(EQIA)study:a national cohort study in china from 2017 to 2019

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Frontiers of Medicine 2024年第2期18卷 315-326页

作者： Wei Cheng Jieqing Chen Xudong Ma Jialu Sun Sifa Gao Ye Wang Longxiang Su Lu Wang Wei Du Huaiwu He Yujie Chen Zunzhu Li Qi Li Jianhua Sun Hongbo Luo Jinbang Liu Guangliang Shan Bing Du Yanhong Guo Dawei Liu Chang Yin Xiang Zhou on behalf of the china National Critical Care Quality Control center-the ECMO quality improvement action(EQIA)study Department of Critical Care Medicine State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalChinese Academy of Medical Science and Peking Union Medical CollegeBeijing100730China Information center Department/Department of Information Management State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalPeking Union Medical College&Chinese Academy of Medical SciencesBeijing100730China Department of Medical Administration National Health Commission of the People’s Republic of ChinaBeijing100044China School of Population Medicine and Public Health Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing100730China Department of Epidemiology and Biostatistics Institute of Basic Medicine SciencesChinese Academy of Medical Sciences(CAMS)&School of Basic MedicinePeking Union Medical CollegeBeijing100730China National Institute of Hospital Administration National Health Commission of the People’s Republic of ChinaBeijing100044China 不详

This cohort study was performed to explore the influence of intensive care unit(ICU)quality on in-hospital mortality of veno-venous(V-V)extracorporeal membrane oxygenation(ECMO)-supported patients in *** study involved all V-V ECMO-supported patients in 318 of 1700 tertiary hospitals from 2017 to 2019,using data from the National Clinical Improvement System and china National Critical Care Quality Control *** quality was assessed by quality control indicators and capacity *** the 2563 V-V ECMO-supported patients in 318 hospitals,a significant correlation was found between ECMO-related complications and *** reintubation rate within 48 hours after extubation and the total ICU mortality rate were independent risk factors for higher in-hospital mortality of V-V ECMO-supported patients(cutoff:1.5%and 7.0%;95%confidence interval:1.05–1.48 and 1.04–1.45;odds ratios:1.25 and 1.23;P=0.012 and P=0.015,respectively).Meanwhile,the V-V ECMO center volume was a protective factor(cutoff of≥50 cases within the 3-year study period;95%confidence interval:0.57–0.83,odds ratio:0.69,P=0.0001).The subgroup analysis of 864 patients in 11 high-volume centers further strengthened these ***,ICU quality may play an important role in improving the prognosis of V-V ECMO-supported patients.

关键词： veno-venous extracorporeal membrane oxygenation in-hospital mortality high-volume centers quality control intensive care unit capacity parameters

Relations between thickness of UHMWPE’s wear debris and positive pressure of tribological system

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Chinese Science Bulletin 2008年第9期53卷 1435-1443页

作者： LIU HongTao1,2,3 & GE ShiRong1,3 1 Institute of Tribology and Reliability Engineering, china University of Mining & technology, Xuzhou 221116, china 2 College of Mechanical and Electrical Engineering, china University of Mining & technology, Xuzhou 221116, china 3 Biotribology center, State Key Laboratory of Tribology, Xuzhou 221116, china Institute of Tribology and Reliability Engineering China University of Mining & Technology Xuzhou 221116 China College of Mechanical and Electrical Engineering China University of Mining & Technology Xuzhou 221116 China Biotribology center State Key Laboratory of Tribology Xuzhou 221116 China

MiaoXAM2.5X-50X Ultrahigh Precision Surface 3D Profiler is introduced to research the relations be- tween thickness of UHMWPE’s wear debris and positive pressure of tribological system. Research re- sults show that thickness of wear debris owns evident classification, and the first grade thickness math model and the second grade thickness math model are built. By the second grade thickness math model, the true force condition in the tribological system can be gotten, and the model can be used as a tool to modify simulating parameters of the tribological system, and it is an important inspecting method to the airtight system which cannot be examined in real time. The first grade thickness math model can describe the true working load and surface condition of work piece in the tribological sys- tem, and is an effective description method for the running condition of frictional pairs. The research results at different lubricating conditions testify the relations between thicknesses of wear debris and positive pressure of the tribological system. The fractal relation between maximal thickness of wear debris and positive pressure is discussed. The conceptions of the immutability principle and charac- teristic granularity of wear debris thickness are brought forward and discussed. In conclusion, as a stable tribological parameter owning mechanical theory basis, wear debris thickness will play an im- portant part in fault diagnosis, especially for the airtight system such as artificial joint.

关键词：摩擦学磨损面厚度分形数学模型

Pre-LOI trajectory maneuvers of the CHANG'E-2 libration point mission

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Science china(Information Sciences) 2012年第6期55卷 1249-1258页

作者： WU WeiRen 1,LIU Yong 2,3,LIU Lei 2,3,ZHOU JianLiang 3,TANG GeShi 2,3 & CHEN YongZhi 3 1 Chinese Lunar Exploration and Space Project center,Beijing 100037,china 2 Science and technology on Aerospace Flight Dynamics Laboratory,Beijing 100094,china 3 Beijing Aerospace Control center,Beijing 100094,china 1. Chinese Lunar Exploration and Space Project center Beijing 100037 China2. Science and Technology on Aerospace Flight Dynamics Laboratory Beijing 100094 China3. Beijing Aerospace Control Center Beijing 100094 China

This paper addresses pre-LOI (before Lissajous orbit insertion) trajectory maneuvers for the libration point mission of CHANG'E-2,which is the first Chinese satellite to fly to the Sun-Earth L2 libration point and the first satellite ever to fly to the L2 point from lunar ***,a transfer trajectory for the mission is designed based on InterPlanetary Superhighway theory under the constraint of the remaining propellant,TT&C (telemetry,track and command) and sunlight *** effects of trajectory maneuver errors on the mission are also ***,based on the analysis results,the article investigates the trajectory maneuver schemes for the lunar escape and transfer trajectory maneuvers employing mathematical models and operational *** mission status based on our maneuver schemes is then presented,and the results of control operation and corresponding analysis are provided in ***,the future trajectory maneuver in the Lissajous orbit is *** to the analysis of the CHANG'E-2 TT&C data,the trajectory maneuver schemes proposed in the article work properly and efficiently.

关键词： CHANG’E-2 libration point trajectory maneuver escape trajectory transfer trajectory

Regional differences and determinants of built-up area expansion in china

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Science china Earth Sciences 2007年第12期50卷 1835-1843页

作者： HUANG JiKun1,2,ZHU LiFen3,1 & DENG XiangZheng1,2 1 center for Chinese agricultural Policy,Chinese Academy of Sciences,Beijing 100101,china 2 Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,china 3 Research center of the Economy of the Upper Reaches of the Yangtze River,Chongqing technology and Business University,Chongqing 400067,china 1. center for Chinese agricultural Policy Chinese Academy of Sciences Beijing 100101 China 2. Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China 3. Research center of the Economy of the Upper Reaches of the Yangtze River Chongqing Technology and Business University Chongqing 400067 China

Based on remote sensing data on land use provided by the Chinese Academy of Sciences and socio-economic data collected by the authors,this paper analyzes the trends and regional differences in built-up area(BUA) expansion in china from the late 1980s to 2000,and empirically estimates the major determinants of BUA expansion in different regions in 1996―*** 1989―2000,although china's overall BUA expansion accelerated,the trends differed significantly among *** expansion in the central and western regions accelerated significantly,but it slowed down considerably in the east-ern *** estimation results from our econometric analysis reveal that BUA expansion in the eastern region reached a period when economic growth had no further significant impact on per capita BUA,the land utilization in this region has become more intensive with further expansion of the *** the central and western regions,the BUA has expanded remarkably due to the relatively more flexible land development policies and the relatively cheap land ***,as the econ-omy continues to grow rapidly,policies relating to BUA expansion and cultivated land reductions may face more serious challenges in the central and western regions.

关键词： built-up area, land use, regional difference, determinants, china