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Orbit determination and prediction accuracy analysis for a regional tracking network

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Science china(Physics,Mechanics & Astronomy) 2010年第6期53卷 1130-1138页

作者： zhou ShanShi 1,2,3 ,HU XiaoGong 1 & wu Bin 1 1 shanghai astronomical observatory,chinese academy of sciences,shanghai 200030,china 2 Graduate University of chinese academy of sciences,Beijing 100049,china 3 Research Center of GNSS,wuhan 430079,china shanghai astronomical observatory Chinese Academy of Sciences Shanghai China Graduate University of chinese academy of sciences Beijing China Research Center of GNSS Wuhan China

china's COMPASS satellite navigation system relies on a regional tracking network to provide navigation services. Limited by its geographic border,the regional network is able to cover only 30% of the medium-earth-orbits(MEO). Accuracy of determined and predicted orbits is not able to satisfy system requirements if the tracking data processing strategy for global tracking network processing is used for the regional network. Two major error sources for orbital prediction are accuracy of initial orbital elements and dynamical modeling. To achieve better prediction accuracy,we propose a two-step orbit determination and prediction strategy. For step 1,only solar radiation pressure(SRP) parameters are estimated along with the orbital elements and other parameters; for step 2,all parameters are estimated but the SRP parameters are tightly constrained to their step 1 estimates. Experimenting with data from a regional GPS network,we conclude for orbital prediction using the proposed two-step strategy,the average user range error(URE) for 24-h prediction arcs is better than 0.6 m.

关键词： orbit determination and prediction regional tracking network URE

Early lung injury contributes to lung fibrosis via AT1 receptor in rats

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Acta Pharmacologica Sinica 2007年第2期28卷 227-237页

作者： Fang-ping CHEN~(1,2) Li-kun GONG~1 Ling ZHANG~3 Hui WANG~(1,2) xin-ming QI~(1,2) Xiong-fei wu~(1,2) Ying XIAO~(1,2) Yan CAI~(1,2) Lin-lin LIU~(1,2) Xiang-hong LI~1 Jin REN~(1,4)1 State Key Laboratory of Drug Research,shanghai Institute of Materia Medica,shanghai Institutes for Biological sciences,chinese academy of sciences,shanghai 201203,china 2 Graduate School of the chinese academy of sciences,shanghai Branch,shanghai 200031,china 3 shanghai Pulmonary Hospital,shanghai 200043,china State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China Graduate School of the chinese academy of sciences Shanghai Branch Shanghai China shanghai Pulmonary Hospital Shanghai China

Aim:Angiotensin Ⅱ is believed to play an important role in tissue repair andremodeling in lungs by the angiotensin type I(AT1)receptor via a number ofpotential ***,the role of the AT1 receptor in early lung injuryhas not been ***:Bleomycin-induced pulmonary fibrosis(PF)in rats was utilized to value the treatment with valsartan,an AT1 receptorantagonist,by measurement of body weight,wet weight of the left lung,hydroxy-proline content,mRNA expression of collagen Ⅰ/Ⅲ,and the degree of fibrosis inlung tissues on d *** injury in the early phase was assessed on d 1,3 and7 by apoptosis,malondialdehyde content,myeloperoxidase activity,inflamma-tory cell count and protein *** converting enzyme(ACE)activ-ity and the AT1 receptor in lung tissues were analyzed by biochemistry methodand Western blotting,***:Valsartan ameliorated PF induced bybleomycin in the rats on d *** bleomycin was injected intratracheally,in-creases in the lung AT1 receptor and ACE activity were observed by d 1,3 and *** injury deteriorated in the early *** reduced the increase of theAT1 receptor,ACE activity and lung injury induced by bleomycin in the ***:These observations suggest that angiotensin Ⅱ may play apotent role in early lung injury via the AT1 ***1 receptor antagonistsshould be assessed as potential new therapies for fibrotic lung disease.

关键词： angiotensin II AT1 receptor pulmonary fibrosis lung injury

The use of laser ranging to measure space debris

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Research in Astronomy and Astrophysics 2012年第2期12卷 212-218页

作者： Zhong-Ping Zhang 1,2,Fu-Min Yang 1,Hai-Feng Zhang 1,Zhi-Bo wu 1,2,Ju-Ping Chen 1,2,Pu Li 1 and Wen-Dong Meng 1 1 shanghai astronomical observatory,chinese academy of sciences,shanghai 200030,china 2 Key Laboratory of Space Object and Debris Observation,chinese academy of Science,Nanjing 210008,china shanghai astronomical observatory Chinese Academy of Sciences Shanghai 200030 China Key Laboratory of Space Object and Debris Observation Chinese Academy of Science Nanjing 210008 China

Space debris is a major problem for all the nations that are currently active in space. Adopting high-precision measuring techniques will help produce a reliable and accurate catalog for space debris and collision avoidance. Laser ranging is a kind of real-time measuring technology with high precision for space debris observation. The first space-debris laser-ranging experiment in china was performed at the shanghai observatory in July 2008 with a ranging precision of about 60-80 cm. The experi- mental results showed that the return signals from the targets with a range of 900 km were quite strong, with a power of 40W （2J at 20 Hz） using a 10ns pulse width laser at 532 nm wavelength. The performance of the preliminary laser ranging system and the observed results in 2008 and 2010 are also introduced.

关键词： astrometry - catalogs - space debris - laser ranging - observation

Orbit determination for geostationary satellites with the combination of transfer ranging and pseudorange data

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Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1746-1754页

作者： GUO Rui1,2,3,4,HU XiaoGong2,4,LIU Li1,wu XiaoLi1,HUANG Yong2,4 & HE Feng1 1 Beijing Global Information Application and Development Center,Beijing 100094,china 2 shanghai astronomical observatory,chinese academy of sciences,shanghai 200030,china 3 Graduate University of chinese academy of sciences,Beijing 100049,china 4 Space Navigation and Positioning Technology,Laboratory of shanghai Municipal,shanghai 200030,china Beijing Global Information Application and Development Center Beijing China shanghai astronomical observatory Chinese Academy of Sciences Shanghai China Graduate University of chinese academy of sciences Beijing China Space Navigation and Positioning Technology Laboratory of Shanghai Municipal Shanghai China

Geostationary satellites(GEOs) play a significant role in the regional satellite navigation *** experiments show that the clock corrections could be mitigated through a single strategy or double differencing strategies for a navigation constellation,but for the mode of individual GEO orbit determination,high precision orbit and clock correction could not be obtained in the orbit determination based on the pseudorange data.A new GEO combined precise orbit determination(POD) strategy is studied in this paper,which combines pseudorange data and C-band transfer ranging *** strategy overcomes the deficiency of C-band transfer ranging caused by limited stations and tracking time *** the combination of transfer ranging and pseudorange data,clock corrections between the GEO and the stations can be estimated simultaneously along with orbital parameters,maintaining self-consistency between the satellite ephemeris and clock correction *** error covariance analysis is conducted to illuminate the contributions from the transfer ranging data and the psudoranging *** data collected for a chinese GEO satellite with 3 C-band transfer ranging stations and 4 L-band pseudorange tracking stations,POD experiments indicate that a meter-level accuracy is *** root-mean-square(RMS) of the post-fit C-band ranging data is about 0.203 m,and the RMS of the post-fit pseudorange is 0.408 *** component errors of the POD experiments are independently evaluated with the satellite laser ranging(SLR) data from a station in Beijing,with the residual RMS of 0.076 *** SLR evaluation also suggests that for 2-h orbital predication,the predicted radial error is about 0.404 m,and the clock correction error is about 1.38 *** for the combination of one C-band transfer ranging station and 4 pseudorange stations,POD is able to achieve a reasonable accuracy with the radial error of 0.280 m and the 2-h predicted radial error of 0.888 *** syn

关键词： satellite navigation precise orbit determination pseudorange equipment ranging delay GEO SLR

Altered expression of cytochrome P450 and possible correlation with preneoplastic changes in early stage of rat hepatocarcinogenesis

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Acta Pharmacologica Sinica 2005年第6期26卷 737-744页

作者： Lin-lin LIU~(2,3), Li-kun GONG~(2,3), xin-ming QI~(2,3),Yan CAI~(2,3), Hui WANG~2, Xiong-fei wu~(2,3),Ying XIAO~(2,3), Jin REN~(2,4) ~2 State Key Laboratory of Drug Research, shanghai Institute of Materia Medica, shanghai Institutes for Biological sciences, chinese academy of sciences, shanghai 201203, china ~3 Graduate School of the chinese academy of sciences, shanghai 201203, china State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China Graduate School of the chinese academy of sciences Shanghai China

Aim: Correlation of cytochrome P450 (CYPs) with preneoplastic changes in the early stage of hepatocarcinogenesis is still unclear. To detect the expression of carcinogen-metabolizing related microsomal P450 enzymes, namely the CYP1 Al, CYP1A2, CYP2B1/2, CYP2E1, and CYP3A, we performed the medium-term bioas-say of Ito's model in Sprague-Dawley rats. Methods: The amount and activity of CYP were assessed by biochemical and immunohistochemical methods in week 8. The correlation between CYP expression and microsomal oxidative stress was investigated by comparing the generation of microsomal lipid peroxidation in the presence or absence of specific CYP inhibitor. Results: In the DEN-2-AAF and 2-AAF alone groups, the expression of CYP1 Al and CYP2E1 were up-regulated and the expression of CYP2B1/2 and CYP1A2 were quite the contrary. Strong staining of CYP2E1 and CYP2B1/2 was found around the centrolobular vein and weak staining in the altered hepatic foci revealed by immunohistochemical procedure. There was no significant change in the activity of CYP3A among the 4 groups. Altered hepatic tissue bore more microsomal NADPH (nicotinamide adenine dimucleotide phosphate,reduced form)-dependent lipid peroxidation than normal tissue. And the difference among the 4 groups disappeared when CYP2E1 was inhibited. More microsomal lipid peroxidation was generated when incubated with CYP1A inhibitor a-naphthoflavone. Conclusion: CYP altered their expression levels and these alterations can play important roles in the alteration of cell redox status of preneoplastic tissue in the early stage of hepatocarcinogenesis.

关键词： cytochrome P450 preneoplastic changes hepatocarcinogensis

Identification and Characterization of hmr19 Gene Encoding a Multidrug Resistance Efflux Protein from Streptomyces hygroscopicus *** Strain 10-22

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Acta Biochimica et Biophysica Sinica 2004年第8期36卷 519-528页

作者： Lei QIN , Heng-An WANG1 , Zhong-Qin wu, Xiao-Feng ZHANG, Mei-Lei JIN,Zi-xin DENG2, and Guo-Ping ZHAOshanghaiResearch Center of Biotechnology, shanghai Institute for Biological sciences, chinese academy of sciences,Graduate School of the chinese academy of sciences, shanghai 200233, china 1School of Agriculture and Biology, shanghai Jiaotong University, shanghai 201101, china 2School of Life Science and Biotechnology, shanghai Jiaotong University, shanghai 200030, china shanghai Research Center of Biotechnology Shanghai Institute for Biological Sciences Chinese Academy of Sciences Graduate School of the Chinese Academy of SciencesShanghai 200233 China School of Agriculture and Biology Shanghai Jiaotong UniversityShanghai 201101 China School of Life Science and Biotechnology Shanghai Jiaotong UniversityShanghai 200030 China

The hmr19 gene was cloned from Streptomyces hygroscopicus subsp. yingchengensis strain 10- 22, a bacterium strain producing agricultural antibiotics. Sequence similarity comparison indicates that hmr19 gene may encode a predicted protein with 14 putative transmembrane α-helical spanners, belonging to the drug:H+ antiporter-2 family of the major facilitator superfamily. The expression of hmr19 in the mycelium of strain 10-22 was detected by Western blotting analysis. Gene replacement technology was employed to construct an hmr19 disruption mutant. The growth inhibition test against different antibiotics indicated that the mutant strain was 5–20 fold more susceptible to tetracycline, vancomycin and mitomycin C than the parental wild type strain. The mutant took up tetracycline much faster and accumulated more antibiotics than the wild type strain 10-22. While with the addition of an energy uncoupler, carbonyl cyanide m- chlorophenylhydrazone, the characteristics of the accumulation of [3H]tetracycline in these two strains were almost the same. It was thus concluded that hmr19 encoded a multidrug resistance efflux protein.

关键词： multidrug resistance (MDR) gene replacement (knockout) Streptomyces Streptomyces hygroscopicus subsp. yingchengensis strain 10-22

Numerical simulation of hot accretion flows with thermal conduction

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 168-172页

作者： wu MaoChun,YUAN Feng & BU DeFu Key Laboratory for Research in Galaxies and Cosmology,shanghai astronomical observatory,chinese academy of sciences,shanghai 200030,china Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai China

We report on the effects of isotropic thermal conduction in non-radiative collisionless accretion flows in two *** comparison to accretion flows without conduction,we find that the disk generally becomes cooler and ***,the magnitude of this effect depends on the kinetic viscosity *** it is proportional to density,the density profile of the accretion flow is flat,therefore the effect is not very ***,if it is proportional to r1/2,as is usual for the "α" disk description,the density profile is ***,the effect will be much more obvious,with the temperature profile of the accretion flow becoming much *** will have important observational consequences.

关键词： black hole accretion disk thermal conduction

The radio structure of BL Lac object S5 2007+777

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 187-190页

作者： wu ZhongZu1,3,GU MinFeng2 & CHEN YongJun2 1 College of Science,Guizhou University,Guiyang 550025,china 2 Key Laboratory for Research in Galaxies and Cosmology,shanghai astronomical observatory,chinese academy of sciences,shanghai 200030,china 3 NAOC-GZU Sponsored Center for Astronomy,Guizhou University,Guiyang 550025,china College of Science Guizhou University Guiyang China NAOC-GZU Sponsored Center for Astronomy Guizhou University Guiyang China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai China

BL Lac object S5 2007+777 has been classified as a HYMOR(Hybrid Morphology radio source) for its hybrid FR I and FR II radio *** is one of four BL Lac objects with a kpc scale extended X-ray *** this paper,we searched the unpublished European VLBI Network(EVN) archived high resolution data for this source,and present the high resolution radio *** EVN images all show a core-jet structure in 1.6,5 and 8 *** combination with the VLA data in the literature,we found position angle differences(△PA) of about 10°-20° between pc and kpc scale jet *** brightness temperature estimated from multi-band EVN images are around 1011.2-1011.8 K,from which the Doppler factor ranges from 3.2 to *** found significant flux variations of the radio core in 1.6 and 5 GHz,from which we derived the variability in brightness temperature Tvar to be 1013.6 K and 1014.0 K,corresponding to the Doppler factors of 9.3 and 12.4,respectively.

关键词： active galactic nuclei VLBI BL Lac objects

The correlation timescale of the X-ray flux during the outbursts of soft X-ray transients

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 161-167页

作者： wu YuXiang1,2,YU WenFei1 & LI TiPei2 1 shanghai astronomical observatory,shanghai 100012,china 2 Department of Engineering Physics & Center for Astrophysics,Tsinghua University,Beijing 100084,china shanghai astronomical observatory Shanghai China Department of Engineering Physics & Center for Astrophysics Tsinghua University Beijing China

Recent studies of black hole and neutron star low mass X-ray binaries(LMXBs) show a positive correlation between the X-ray flux at which the low/hard(LH)-to-high/soft(HS) state transition occurs and the peak flux of the following HS *** analyzing the data from the All Sky Monitor(ASM) onboard the Rossi X-ray Timing Explorer(RXTE),we show that the HS state flux after the source reaches its HS flux peak still correlates with the transition flux during soft X-ray transient(SXT) *** studying large outbursts or flares of GX 339-4,Aql X-1 and 4U 1705-44,we have found that the correlation holds up to 250,40,and 50 d after the LH-to-HS state transition,*** time scales correspond to the viscous time scale in a standard accretion disk around a stellar mass black hole or a neutron star at a radius of-104-5 Rg,indicating that the mass accretion rates in the accretion flow either correlate over a large range of radii at a given time or correlate over a long period of time at a given *** the accretion geometry is a two-flow geometry composed of a sub-Keplerian inflow or outflow and a disk flow in the LH state,the disk flow with a radius up to-105 Rg would have contributed to the nearly instantaneous non-thermal radiation directly or indirectly,and therefore affects the time when the state transition occurs.

关键词： accretion disks black hole physics star:individual(Aquila X-1 GX 339-4 4U 1705-44)