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A method of measuring the [α/Fe] ratios from the spectra of the LAMOST survey

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Research in Astronomy and Astrophysics 2016年第7期16卷 83-96页

作者： Ji Li Chen Han Mao-Sheng Xiang Jian-Rong Shi Jing-Kun Zhao Xiao-Wei Liu Hua-Wei Zhang hai-bo yuan Xuan Ci Xiao-Feng Zhang Yue-Xiang Wang Yang Huang Yong Zhang Yong-Hui Hou Yue-Fei Wang Zi-Huang Cao Department of Space Science and Astronomy Hebei Normal University Shijiazhuang 050024 China Department of Astronomy Peking University Beijing 100871 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Kavli Institute for Astronomy and Astrophysics Peking University Beijing 100871 China Department of Astronomy Beijing Normal University Beijing 100875 China Nanjing Institute of Astronomical Optics & Technology National Astronomical Observatories Chinese Academy of Sciences Nanjing 210042 China

The [α/Fe] ratios in stars are good tracers to probe the formation history of stellar populations and the chemical evolution of the Galaxy. The spectroscopic survey of LAMOST provides a good opportunity to determine [α/Fe] of millions of stars in the Galaxy. We present a method of measuring the [α/Fe]ratios from LAMOST spectra using the template-matching technique of the LSP3 pipeline. We use three test samples of stars selected from the ELODIE and MILES libraries, as well as the LEGUE survey to validate our method. Based on the test results, we conclude that our method is valid for measuring [α/Fe]from low-resolution spectra acquired by the LAMOST survey. Within the range of the stellar parameters Teff= [5000, 7500] K, log g = [1.0, 5.0] dex and [Fe/H]= [onsistent with values derived from high-resolution spectra,-1.5, ＋0.5] dex, our [α/Fe] measurements are c and the accuracy of our [α/Fe] measurements from LAMOST spectra is better than 0.1 dex with spectral signal-to-noise higher than 20.

关键词： Galaxy evolution stars abundances stars fundamental parameters techniques spectroscopy surveys methods data analysis

On the LSP3 estimates of surface gravity for LAMOST-Kepler stars with asteroseismic measurements

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Research in Astronomy and Astrophysics 2016年第3期16卷 81-90页

作者： Juan-Juan Ren Xiao-Wei Liu Mao-Sheng Xiang Yang Huang Saskia Hekker Chun Wang hai-bo yuan Alberto Rebassa-Mansergas Bing-Qiu Chen Ning-Chen Sun Hua-Wei Zhang Zhi-Ying Huo Wei Zhang Yong Zhang Yong-Hui Hou Yue-Fei Wang Department of Astronomy Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Max-Planck-Institut fiir Sonnensystemforschung Justus-von-Liebig-Weg 337077 GottingenGermany Stellar Astrophysics Centre Department of Physics and AstronomyAarhus UniversityNy Munkegade 1208000 Aarhus CDenmark Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012China Nanjing Institute of Astronomical Optics&Technology National Astronomical ObservatoriesChinese Academy of SciencesNanjing 210042China

Asteroseismology allows for deriving precise values of the surface gravity of stars. The accurate asteroseismic determinations now available for the large number of stars in the Kepler fields can be used to check and calibrate surface gravities that are currently being obtained spectroscopically for a huge number of stars targeted by large-scale spectroscopic surveys, such as the on-going Large Sky Area Multi-Object Fiber Spectroscopic Telescope （LAMOST） Galactic survey. The LAMOST spectral surveys have obtained a large number of stellar spectra in the Kepler fields. Stellar atmospheric parameters of those stars have been determined with the LAMOST Stellar Parameter Pipeline at Peking University （LSP3）, by template matching with the MILES empirical spectral library. In the current work, we compare surface gravities yielded by LSP3 with those of two asteroseismic samples-- the largest Kepler asteroseismic sample and the most accurate Kepler asteroseismic sample. We find that LSP3 surface gravities are in good agreement with asteroseismic values of Hekker et al., with a dispersion of -0.2 dex. Except for a few cases, asteroseismic surface gravities ofHuber et al. and LSP3 spectroscopic values agree for a wide range of surface gravities. However, some patterns in the differences can be identified upon close inspection. Potential ways to further improve the LSP3 spectroscopic estimation of stellar atmospheric parameters in the near future are briefly discussed. The effects of effective temperature and metallicity on asteroseismic determinations of surface gravities for giant stars are also discussed.

关键词： methods: data analysis -- stars: fundamental parameters -- stars: spectroscopic -- stars general -- stars: oscillations

Comparison of drug eluting stents with bare metal stents in daily practice for bifurcation lesions in Chinese patients

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Chinese Medical Journal 2006年第14期119卷 1157-1164页

作者： KANG Sheng YANG Yue-jin XU bo CHEN Ji-lin QIAO Shu-bin YAO Min CHEN Jue WU Yong-jian LIU hai-bo DAI Jun yuan Jin-qing LI Jian-jun GAO Run-lin Department of Cardiology Cardiovascular Institute ＆ Fuwai Hospital Chinese Academy of Medical Sciences ＆ Peking Union Medical College Beijing 100037 China

Background Recently, numerous randomized and controlled trials have demonstrated great advantages of drug eluting stents （DES） with respect to significant reduction of restenosis and recurrence of symptoms and improvement of clinical outcomes after percutaneous coronary intervention （PCI）. Little is known about the comparative effects between DES and bare metal stents （BMS） for bifurcation angioplasty in the Chinese population. We compared the inpatient and 7-month follow-up outcomes between DES and BMS for the treatment of bifurcation lesions. Methods From April 2004 to October 2005, 291 Chinese patients [85.9% male, mean age （57.8± 10.4） years] underwent DES （387 lesions） and/or BMS （297 lesions） implantation for bifurcation lesions. Clinical and angiographic follow-up was performed at 7 months. Results Compared with BMS group, patients in DES group had significantly lower rates of restenosis at main branch （9.5% vs 28.7%, P 〈 0.001） or side branch （14.5% vs 37.0%, P 〈 0.001） and major adverse cardiac events （MACE）（14.0% vs 26.3%, P = 0.000）. The occurrence rate of late in-stent thrombosis did not differ between the two groups in both main （0.8% vs 0, P = 0.224） and side branches （1.4% vs 0, P =0.198）. Target lesion revascularization （TLR） was less frequent in DES group for main branch （8.3% vs 21.3%, P 〈 0.001） and for side branch （7.6% vs 23.5%, P 〈 0.001）. Multivariate regression analysis revealed that total stent length （OR = 1.029, P = 0.01）, postprocedural in-stent minimum lumen diameter （OR = 0.476, P = 0.03） and stent type （OR = 3.988, P = 0.0001） were independent predictors of TLR for main branch. Prior history of coronary intervention （OR = 2.424, P =0.041）, angulated lesion （OR = 2.337, P = 0.033）, postdilation （OR = 0.267, P = 0.035） and stent type （DES vs BMS, OR = 5.459, P = 0.000） were independent predictors of TLR for side branch. Conclusion The implantation of DES may be associated with greater reduction of restenosis and TLR than BMS in bi

关键词： percutaneous coronary intervention drug eluting stent bare metal stent bifurcation

Is adjunctive balloon postdilatation necessary with drug-eluting stents？ One center experience in Chinese patients

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Chinese Medical Journal 2008年第6期121卷 513-517页

作者： GAO Zhan YANG Yue-jin XU bo CHEN Ji-lin QIAO Shu-bin YAO Min CHEN Jue WU Yong-jian LIU hai-bo DAI Jun yuan Jin-qing LI Jian-jun GAO Run-lin Department of Cardiology Cardiovascular Institute and FuwalHospital Chinese Academy of Medical Sciences and Peking UnionMedical College Beijing 100037 China

Background With the advent of drug-eluting stents （DES） and much lower rates of target vessel revascularization （TVR）, whether adjunctive balloon postdilatation can further optimize outcome is still unknown. The present study was to compare the outcomes of postdilatation with un-postdilatation following deployment of DES. Methods From April 2004 to September 2006, 6479 consecutive Chinese patients who underwent DES implantation, including 1769 with postdilatation （1454 male, （57.9 ± 10.8） years old） and 4710 without postdilatation （3819 male, （57.9 ± 10.6） years old） were analyzed. Clinical and angiographic follow-up was performed at 7 months. Results Compared with the un-postdilatation group, the postdilatation group had more complex lesions and larger relevant vessel diameter （RVD）. In the postdilatation group, in-stent residual restenosis was significantly improved right after the procedure （（16.80±5.88）% vs （19.60±6.07）%; P=0.000）. There was no statistical difference in the major adverse cardiac events （MACE） rate between the groups （2.9% vs 3.3%; P=0.420）, and there were also no statistical differences in death, acute myocardial infarction （AMI） and target lesion revascularization （TLR） rates in the two groups （0.1% vs 0.4%, P=0.127; 1.7% vs 1.3%, P=0.229; and 1.5% vs 2.0%, P=0.206, respectively）. The in-stent thrombosis rate was almost the same in both groups （0.5% vs 0.5%; P=1.000）. Seven months angiographic follow-up results showed that both in-stent and in-segment restenosis rates were lower in the postdilatation group （8.8% vs 15.6%, P=0.000; and 10.5% vs 17.3%, P=0.000）, and so were instent and in-segment late loss （（0.32±0.12） mm vs （0.49±0.13） mm, P=0.000; and （0.24±0.08） mm vs （0.36±0.09） mm, P=0.001 ）. Conclusion Postdilatation after DES deployment was safe and could reduce the restenosis rate, especially for more complex lesions.

关键词： percutaneous coronary intervention drug-eluting stent postdilatation

Binary Star Fractions from the LAMOST DR4

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Research in Astronomy and Astrophysics 2018年第5期18卷 47-58页

作者： Zhi-Jia Tian Xiao-Wei Liu hai-bo yuan Bing-Qiu Chen Mao-Sheng Xiang Yang Huang Chun Wang Hua-Wei Zhang Jin-Cheng Guo Juan-Juan Ren Zhi-Ying Huo Yong Yang Meng Zhang Shao-Lan Bi Wu-Ming Yang Kang Liu Xian-Fei Zhang Tan-Da Li Ya-Qian Wu Jing-Hua Zhang Department of Astronomy Peking University Beijing 100871 China Department of Astronomy Beijing Normal University Beijing 100875 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100101 China Department of Astronomy Yunnan University Kunming 650091 China

Stellar systems composed of single, double, triple or higher-order systems are rightfully regarded as the fundamental building blocks of the Milky Way. Binary stars play an important role in formation and evolution of the Galaxy. Through comparing the radial velocity variations from multiepoch observations, we analyze the binary fraction of dwarf stars observed with LAMOST. Effects of different model assumptions, such as orbital period distributions on the estimate of binary fractions,are investigated. The results based on log-normal distribution of orbital periods reproduce the previous complete analyses better than the power-law distribution. We find that the binary fraction increases with Teff and decreases with [Fe/H]. We first investigate the relation between α-elements and binary fraction in such a large sample as provided by LAMOST. The old stars with high [α/Fe] dominate with a higher binary fraction than young stars with low [α/Fe]. At the same mass, earlier forming stars possess a higher binary fraction than newly forming ones, which may be related with evolution of the Galaxy.

关键词： binaries general- binaries spectroscopic - Galaxy stellar content - stars statistics- surveys

Comparison of immediate and followup results between transradial and transfemoral approach for percutaneous coronary intervention in true bifurcational lesions

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Chinese Medical Journal 2007年第7期120卷 539-544页

作者： YANG Yue-jin XU bo CHEN Ji-lin KANG Sheng QIAO Shu-bin QIN Xue-wen YAO Min CHEN Jue WU Yong-jian LIU hai-bo yuan Jin-qing YOU Shi-jie LI Jian-jun DAI Jun GAO Run-lin Centre for Coronary Artery Disease Department of Cardiology Cardiovascular Institute and Fuwai Hospital Chinese Academy of Medical Sciences ＆ Peking Union Medical College Beijing 100037 China

Background A comparison of efficacy and safety between transradial and transfemoral approach for percutaneous coronary intervention （PCI） in bifurcations has not been done. This study evaluated feasibility of transradial PCI （TRI） and compared the immediate and followup results with transfemoral PCI （TFI） in bifurcations. Methods One hundred and thirty-four consecutive patients with bifurcations were treated with PCI in our hospital from April 2004 to October 2005. Of these, there were 60 patients （88 lesions） in TRI group and 74 patients （101 lesions） in TFI group. Bifurcations type was classified according to the Institut Cardiovasculaire Paris Sud Classification. Results TRI group had smaller stent diameter （（3.06±0.37） mm vs （3.18±0.35） mm, P=0.023） and postprocedural in-stent minimum lumen diameter （（2.62±0.37） mm vs （2.74±0.41） mm, P=0.029） than TFI, but there were not significant differences in in-stent subacute thrombosis rate （0% vs 1.0%, P=0.349）, target lesion revascularization （TLR）（0% vs 1.0%, P=0.349） following procedure and thrombosis （2.3% vs 1.0%, P=0.482）, in-stent restenosis （12.5% vs 10.9%, P=0.731）, in-segment restenosis （17.0% vs 14.9%, P=0.681）, TLR （10.2% vs 13.9%, P=0.446） and TLR-free cumulative survival rate （89.8% vs 86.1%, P=0.787） at seven months followup. No death was reported in the two groups. Conclusion Transradial intervention is feasible and appears to be as effective and safe as transfemoral PCI in treatment of true bifurcational lesions.

关键词： transradial percutaneous coronary intervention transfemoral percutaneous coronary intervention bifurcational lesions treatment outcome

变基线约束的GNSS单频单历元姿态测量新算法

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中国惯性技术学报 2017年第6期25卷 759-764页

作者：赵修斌吴洪涛庞春雷仝海波权源空军工程大学信息与导航学院西安710077

针对基于值域的GNSS姿态测量算法没有考虑工程应用中基线小动态变化的问题,推导了模糊度反约束值域搜索算法的搜索误差模型,研究了该误差模型对算法成功率的影响,分析了利用基线残差最小固定模糊度在工程应用中的不可靠性,提出了变基线... 详细信息

针对基于值域的GNSS姿态测量算法没有考虑工程应用中基线小动态变化的问题,推导了模糊度反约束值域搜索算法的搜索误差模型,研究了该误差模型对算法成功率的影响,分析了利用基线残差最小固定模糊度在工程应用中的不可靠性,提出了变基线约束的单频单历元姿态测量新算法:以基线长度小动态变化为约束,以惯性导航设备(INS)提供的粗略方位角、俯仰角为辅助,通过对基线长度、俯仰角、方位角三维搜索确定模糊度搜索域,以基于模糊度残余最小的无参化目标函数固定模糊度。试验结果表明,新算法能够在基线动态变化±10 cm、方位角偏差±5°、俯仰角偏差±5°情况下,实现模糊度的单频单历元固定和载体高精度姿态测量,并具有较高的成功率。

关键词：姿态测量基线变化直接三维搜索无参化目标函数单频单历元

FK506 contributes to peripheral nerve regeneration by inhibiting neuroinflammatory responses and promoting neuron survival

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Neural Regeneration Research 2025年第7期20卷 2108-2115页

作者： Yuhui Kou Zongxue Jin Yusong yuan bo Ma Wenyong Xie Na Han Department of Trauma and Orthopedics Peking University People’s HospitalBeijingChina National Center for Trauma Medicine Peking University People’s HospitalBeijingChina Key Laboratory of Trauma and Neural Regeneration(Peking University) Ministry of EducationBeijingChina Trauma Medicine Center Peking University People’s HospitalBeijingChina Department of Orthopedics China-Japan Friendship HospitalBeijingChina

FK506(Tacrolimus)is a systemic immunosuppressant approved by the *** and Drug ***506 has been shown to promote peripheral nerve regeneration,however,its precise mechanism of action and its pathways remain *** this study,we established a rat model of sciatic nerve injury and found that FK506 improved the morphology of the injured sciatic nerve,increased the numbers of motor and sensory neurons,reduced inflammatory responses,markedly improved the conduction function of the injured nerve,and promoted motor function *** findings suggest that FK506 promotes peripheral nerve structure recovery and functional regeneration by reducing the intensity of inflammation after neuronal injury and increasing the number of surviving neurons.

关键词： FK506 inflammation motor neurons nerve regeneration neuron peripheral nerve injury sensory neurons

New background quasars in the vicinity of the Andromeda Galaxy discovered with the Guoshoujing Telescope (LAMOST)

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Research in Astronomy and Astrophysics 2010年第7期10卷 612-620页

作者： Zhi-Ying Huo Xiao-Wei Liu hai-bo yuan Hui-Hua Zhang Yong-Heng Zhao Jian-Jun Chen Zhong-Rui Bai Hao-Tong Zhang Hua-Wei Zhang Ruben Garcia-Benito Mao-Sheng Xiang Hong-Liang Yan Juan-Juan Ren Shi-Wei Sun Yong Zhang Ye-Ping Li Qi-Shuai Lu You Wang Ji-Jun Ni hai Wang Department of Astronomy Peking University Beijing 100871 China Kavli Institute for Astronomy and Astrophysics Peking University Beijing 100871 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Department of Astronomy Beijing Normal University Beijing 100875 China Nanjing Institute of Astronomical Optics ＆ Technology Chinese Academy of Sciences Nanjing 210042 China

We present preliminary analyses of spectra of quasar candidates in two Guoshoujing Telescope （GSJT, formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope - LAMOST） test fields near M 31 where one is close to the optical center of the disk and the other is towards the northeastern outskirts of the halo, obtained during the early stage of the GSJT commissioning in the last season of 2009. both fields contain background low-redshift quasar candidates selected from the SDSS photometry. In total, 14 new quasars with redshifts up to 2 and i magnitudes between 16.7 and 19.2, are discovered, including 7 within the 2.5° central region of M 31. We briefly discuss the potential applications of these newly discovered bright quasars.

关键词： galaxies individual (M31) -- quasars general -- quasars emission lines