基于复模态和频响修正方法的磁轴承-转子系统参数识别
|
摘要
支承的动态特性参数对磁轴承-转子系统的动力学性能有十分重要的影响。为了能准确设计系统,提高系统的性能和稳定性,识别磁轴承-转子系统的动态特性参数(支承刚度和阻尼参数)就显得犹为必要。本文围绕支承动态特性参数识别这一主题,尝试两种设计参数型修正方法,基于模型修正程序,最终得到以金属橡胶减振器为二次减振支承的磁轴承-转子系统中磁轴承和金属橡胶环结构两大子结构的动态特性参数。具体研究内容如下:
利用有限元方法和软件技术进行了金属橡胶环结构和磁轴承-转子系统的动力学建模。分析比较了分别以弹簧单元和实体单元为核心的金属橡胶环结构的有限元模型,选择更准确的弹簧单元模型用于修正。以有限元方法对含金属橡胶环的磁轴承-转子系统模型进行了动态特性分析。
利用模态实验数据,运用复模态有限元模型修正方法对金属橡胶环结构进行动态参数识别,模型修正后模态特征值误差较修正前显著降低,说明了所识别参数的准确性,为改进金属橡胶环结构设计提供了参考依据。
研究实现了基于频率响应的模型修正方法,探讨了频响函数频率点选择和残差定义等修正的关键问题。将该方法应用于磁轴承-转子系统,修正后的频响函数与实测频响函数吻合良好,说明此方法能够准确有效地识别出磁轴承的动态特性参数。
The dynamic performance of a rotor-magnetic bearings system largely depends on the bearing’s dynamic parameters. It is essential to identify the exact dynamic parameters such as the stiffness and the damping so as to accurately design the bearing system and to effectively improve the rotor system’s performance and stability. In this paper, two methods have been carried out based on model updating on complex bearing system(set metal rubber annuluse as sencondary vibration damper)and a group of identified dynamic parameters of the metal rubber annulus structure and active megnatic bearing have been obtained. Specific studies are as follows:
The model of the metal rubber was established using finite element (FE) method with related software technologies. The spring element was performed in model updating since its high accuracy compared to the solid element. The dynamic analysis of the metal rubber which attached in the magnetic bearing system was also included in this work.
Based on the data from experimental model analysis (EMA), the radial stiffness and damping parameters of the metal rubber were identified using model updating. That the errors of modal eigenvalues have a clearly decreasing trend indicates the credibility of the identified result which can be useful in the design of metal rubber structure.
This research have paid special attention on some key issues including the method of model updating based on frequency response and the selection of the frequency point of the frequency response function and the definition of the residual. The method was applied on magnetic bearing-rotor system. The results show that this method was in perfect agreement with the real frequency response function from EMA. It also indicates that this method can accurately and efficiently identify the dynamic parameters of magnetic bearing system.
利用有限元方法和软件技术进行了金属橡胶环结构和磁轴承-转子系统的动力学建模。分析比较了分别以弹簧单元和实体单元为核心的金属橡胶环结构的有限元模型,选择更准确的弹簧单元模型用于修正。以有限元方法对含金属橡胶环的磁轴承-转子系统模型进行了动态特性分析。
利用模态实验数据,运用复模态有限元模型修正方法对金属橡胶环结构进行动态参数识别,模型修正后模态特征值误差较修正前显著降低,说明了所识别参数的准确性,为改进金属橡胶环结构设计提供了参考依据。
研究实现了基于频率响应的模型修正方法,探讨了频响函数频率点选择和残差定义等修正的关键问题。将该方法应用于磁轴承-转子系统,修正后的频响函数与实测频响函数吻合良好,说明此方法能够准确有效地识别出磁轴承的动态特性参数。
The dynamic performance of a rotor-magnetic bearings system largely depends on the bearing’s dynamic parameters. It is essential to identify the exact dynamic parameters such as the stiffness and the damping so as to accurately design the bearing system and to effectively improve the rotor system’s performance and stability. In this paper, two methods have been carried out based on model updating on complex bearing system(set metal rubber annuluse as sencondary vibration damper)and a group of identified dynamic parameters of the metal rubber annulus structure and active megnatic bearing have been obtained. Specific studies are as follows:
The model of the metal rubber was established using finite element (FE) method with related software technologies. The spring element was performed in model updating since its high accuracy compared to the solid element. The dynamic analysis of the metal rubber which attached in the magnetic bearing system was also included in this work.
Based on the data from experimental model analysis (EMA), the radial stiffness and damping parameters of the metal rubber were identified using model updating. That the errors of modal eigenvalues have a clearly decreasing trend indicates the credibility of the identified result which can be useful in the design of metal rubber structure.
This research have paid special attention on some key issues including the method of model updating based on frequency response and the selection of the frequency point of the frequency response function and the definition of the residual. The method was applied on magnetic bearing-rotor system. The results show that this method was in perfect agreement with the real frequency response function from EMA. It also indicates that this method can accurately and efficiently identify the dynamic parameters of magnetic bearing system.
引文
[1]郭树涛.主动磁悬浮轴承的工作原理及发展趋势.重庆科技学院学报报,2006,8(4): 47-48.
[2] Guoxin Li,Zongli Lin,Paul E.Allaire,et al.Modeling of a High Speed Rotor Test Rig with Active Magnetic Bearings.Transactions of the ASME.Journal of Vibration and Acoustics, 2006,128::269-281.
[3] Yang Guojun,Xu Yang,Shi Zhengang,et al.Characteristic analysis of rotor dynamics and experiments of active magnetic for HTR-10GT.Nuclear Engineering and Design.2007,237:1363-1371.
[4]李慧敏,曾胜.电磁辅助支承恒压源与恒流源被动式减振之比较.机械工程学报, 2006, 42(2):119-124.
[5]谢振宇,李克雷,赵钦泉,等.带阻尼器磁悬浮轴承转子系统性能的实验分析.航空动力学报,2008,23(7):1312-1317.
[6]梁清泉,张根全.有限元与MARC实现.北京:机械工业出版社,2003:10-36.
[7]杨序贵,刘守圭.基于优化方法的有限元模型修正方法.中山大学学报(自然科学版),2005,44:161-162.
[8] Mottershead J E,Friswell M I.A Survey Model Updating in Structural Dynamics.Journal of Sound and Vibration,1993,167(2):347-375.
[9]张令弥.动态有限元模型修正技术及其在航空航天结构中的应用.强度与环境,1994(2):10-17.
[10]张亚红,赵玉成,等.弹性支承对滑动轴承转子系统稳定性的影响.强度与环境,2004, 31(4):5-18.
[11] J.E.Mottershead,M.I.Friswell.Model Updating in Structural Dynamics:ASurvey.Journal of Sound and Vibration,1993,167(2):347-375.
[12]王彤.复杂结构多输入多输出频域模态参数识别研究及软件实现,[博士学位论文].南京:南京航空航天大学,2003.
[13] R.Tiwari,V.Chakravarthy.Simultaneous Identification of Residual Unbalances and Bearing Dynamic Parameters from Impulse Responses of Rotor–bearing Systems.Mechanical Systems and Signal Processing,2006,20:1590-1614.
[14]王硕桂,夏源明.从随机振动响应中提取滚动轴承的刚度参数.振动工程学报,2004,17(4):388-392.
[15] S.ZIAEI-RAD.Finite Element Model Updating of Rotating Structures Using Different Optimisation Techniques. Iranian Journal of Science & Technology, 2005,29(B6): 569-585.
[16] S.Audebert,T.Chapron,A.C.Leger,et al.Multi-bearing Rotor Model Updating using Experimental Modal and Response Data.Proceedings of the 15th IMAC.Orlando,U.S.A,1997: 162-168.
[17]张令弥,张柏庆,袁向荣.特征向量导数计算各种模态法的比较和发展.应用力学学报,1994,11(3):68-74.
[18]孔翠芳,戴华.用不完全模态数据修正粘性阻尼矩阵.振动工程学报,2005, 18(1):85-90.
[19]杨杰,耿遵敏,谭雪琴.基于复模态的结构有限元动态模型修正理论.振动与冲击,2002, 21(1):30-32.
[20]蒋家尚,袁永新.基于复模态试验数据的粘性阻尼矩阵的修正.振动与冲击,2007, 26(5):74-80.
[21] Yong Lu, Zhenguo Yu.A Two-level Neural Network Approach for Dynamic FE Model Updating Including Damping.Journal of Sound and Vibration, 2004,275:931-952.
[22]冯文贤,陈新.基于试验复模态参数的有限元模型修正.航空学报,1999,20(1):11-16.
[23] H.G.Natake.Die Korrektur des Rechenmodells Eines Elastomechanischen Systems Mittels Gemessener Erzwungener Schwingungen.Ingenieur-Archiv,1977,4(6):169-184.
[24] C.D.Foster.A Method of Improving Finite Element Models by Using Experimental Data:Application and Implications for Vibration Monitoring.International Journal of Mechanical Science,1980,32(3):191-203.
[25] M.Link.Identification and Correction of Errors in Analytical Models Using Test Data:Theoretical and Practical Bounds.Proceedings of the 8th International Modal Analysis Conference,Orlando,Kissimmee,1990,570-578.
[26] Friswell,M.I.Updating Model Parameters from Frequency Domain Data Via Reduced Order Model.Mechanical Systems and Signal Processing.1990,4(5):377-391.
[27] Cottin,N.On the Parameter Identification of Elastommechanical Systems Using Input and Output Residuals.Ingenieur Archive.1984,40(2):378-387.
[28] Fritzen,C.P.Identification of Mass,Damping and Stiffness Matrices of Mechanical Systems.Journal of Vibration,Acoustics,Stress and Reliability in Design,1986,108(4):9-16.
[29] Ljung,J.System Identification.Theory for the Uses Englewood Cliffs,1987:37-40.
[30] Larsson,P.O.Model Updating Using Force Vibration Testing Using Numerical StableFormulations.Proceedings of the 10th International Model Analysis Conference,Orlando,Kissimmee,1992:966-974.
[31]徐张明,高天明,沈荣瀛,华宏星.一种改进的利用频响函数进行有限元模型修正的方法.振动与冲击,2002,21(3):43-46.
[32]徐张明,沈荣瀛,华宏星.基于频响函数相关性的灵敏度分析的有限元模型修正.机械强度,2003,25(1):5-8.
[33]秦仙蓉.基于灵敏度分析的结构计算模型修正及相关问题研究,[博士学位论文].南京:南京航空航天大学,2001.
[34]沃德海伦.模态分析理论与实验(白化同,郭继忠).北京:北京理工大学出版社,2001:20-43.
[35]董其伍.刘启玉.CAE技术回顾与展望.计算机工程与应用,2002(14):82-84.
[36]傅永华.有限元分析基础.武汉:武汉大学出版社,2003:19-96.
[37]王助成,邵敏.有限单元法基本原理和数值方法.北京:清华大学出版社,1997:43-82.
[38]杨剑,张璞,陈火红.新编MD NASTRAN有限元实例教程.北京:机械工业出版社,2008:13-31.
[39]李宇明,郑坚,白鸿柏.金属橡胶材料的动态力学模型.材料研究学报,2003,17(5):499-504.
[40]李宇明,彭威,白鸿柏,等.金属橡胶材料宏观和细观力学模型.机械工程学报,2005, 41(9):38-41.
[41]丁杰.一种新型的梁单元—有限元法在转子动力学中的应用.火控雷达技术,2000,29: 20-28.
[42]李冬伟,白鸿柏,杨建春,等.金属橡胶动力学建模及参数识别,振动与冲击,2005,24(6):57-60.
[43]王新,朱梓根.环形金属橡胶减振器.航空动力学报,1997,12(2):143-145.
[44]马艳红,郭宝亭,朱梓根.金属橡胶材料静态特性的研究.航空动力学报,2004,19(3):326-331.
[45]夏宇宏,闫辉,姜洪源,等.环形金属橡胶隔振器弹性参数的确定.润滑与密封,2005,5(3):34-36.
[46]闫辉,夏宇宏,姜洪源.复杂形状的金属橡胶隔振器当量弹性模量研究.湖南科技大学学报,2008,23(3):46-48.
[47]郭宝亭,朱梓根,崔荣繁,等.金属橡胶材料的理论模型研究.航空动力学报,2004,19(3):314-319.
[48]夏宇宏,姜洪源,敖宏瑞,等.汽车用环形金属橡胶弹性元件的性能研究.机械设计,2002,11(3):8-10.
[49]张芳萍,樊文欣,梁佳.金属橡胶阻尼元件的力学模型及减振特性研究.新技术新工艺,2007,(8):66-68.
[50]张保强.磁轴承-转子系统的有限元模型修正及相关问题研究,[硕士学位论文].南京:南京航空航天大学,2009.
[51]高华.金属橡胶磁悬浮轴承组合支承转子系统动力学特性研究,[硕士学位论文].南京:南京航空航天大学,2009.
[52]李效法.基于灵敏度分析的模型修正研究及其实现.[硕士学位论文].南京:南京航空航天大学,2007.
[53]费庆国.结构动态有限元模型修正技术若干关键问题的研究,[博士学位论文].南京:南京航空航天大学,2004.
[54] Johnson,Erwin H,et al.MSC.NASTRAN 2004 Design Sensitivity and Optimization User’s Guide.MSC.Software,Santa Ana,CA,2003:103-105.
[55] Sondipon Adhikari.Rates of change of eigenvalues and eigenvectors in damped dynamic system.AIAA Journal,1999,37 (11):1452-1458.
[56]傅志方,华宏星.模态分析理论与应用.上海:上海交通大学出版社,2000:183-184.
[57]袁爱民.基于灵敏度分析的有限元模型修正技术若干关键问题研究,[博士学位论文].南京:东南大学,2006.
[58] A.W.Lees,J.K.Sinha,M.I.Friswell,Model-based Identification of Rotating Machines.Mechanical Systems and Signal Processing,2009,(23):1884–1893.
[59]隋允康,杜家政,彭细荣.MSC.Nastran有限元动力分析与优化设计使用教程.北京:科学出版社,2004:3-10.
[60]李海涛,邓樱.MATLAB程序设计教程.北京:高等教育出版社,2002:2-8.
[61]朱凼凼,冯咬齐,向树红.基于频率响应函数的动力学模型修正方法研究.中国工程科学, 2005,(8):89-94.
[62] Kye-Si,Kwon1,Rong-Ming Lin.Frequency Selection Method for FRF-Based Model Updating.Journal of Sound and Vibration,2004,(278):285–306.
[63] Rodrigo Pascual,Roberto Schalchli,Mario Razeto.Damping Identification Using a Robust FRF-Based Model Updating Technique.Proceedings of the XXI International Modal Analysis Conference,Kissimmee,2003:1-14.
[64] D.J.Ewins.Modal Testing Theory and Practice.England:Research Studies Press,1984:153-156.
[65]许本文,焦群英.机械振动与模态分析基础.北京:机械工业出版社,1998:23-28.
[66]《N-Modal模态分析软件用户手册V4.0版》,南京航空航天大学振动工程研究所,2008.
[2] Guoxin Li,Zongli Lin,Paul E.Allaire,et al.Modeling of a High Speed Rotor Test Rig with Active Magnetic Bearings.Transactions of the ASME.Journal of Vibration and Acoustics, 2006,128::269-281.
[3] Yang Guojun,Xu Yang,Shi Zhengang,et al.Characteristic analysis of rotor dynamics and experiments of active magnetic for HTR-10GT.Nuclear Engineering and Design.2007,237:1363-1371.
[4]李慧敏,曾胜.电磁辅助支承恒压源与恒流源被动式减振之比较.机械工程学报, 2006, 42(2):119-124.
[5]谢振宇,李克雷,赵钦泉,等.带阻尼器磁悬浮轴承转子系统性能的实验分析.航空动力学报,2008,23(7):1312-1317.
[6]梁清泉,张根全.有限元与MARC实现.北京:机械工业出版社,2003:10-36.
[7]杨序贵,刘守圭.基于优化方法的有限元模型修正方法.中山大学学报(自然科学版),2005,44:161-162.
[8] Mottershead J E,Friswell M I.A Survey Model Updating in Structural Dynamics.Journal of Sound and Vibration,1993,167(2):347-375.
[9]张令弥.动态有限元模型修正技术及其在航空航天结构中的应用.强度与环境,1994(2):10-17.
[10]张亚红,赵玉成,等.弹性支承对滑动轴承转子系统稳定性的影响.强度与环境,2004, 31(4):5-18.
[11] J.E.Mottershead,M.I.Friswell.Model Updating in Structural Dynamics:ASurvey.Journal of Sound and Vibration,1993,167(2):347-375.
[12]王彤.复杂结构多输入多输出频域模态参数识别研究及软件实现,[博士学位论文].南京:南京航空航天大学,2003.
[13] R.Tiwari,V.Chakravarthy.Simultaneous Identification of Residual Unbalances and Bearing Dynamic Parameters from Impulse Responses of Rotor–bearing Systems.Mechanical Systems and Signal Processing,2006,20:1590-1614.
[14]王硕桂,夏源明.从随机振动响应中提取滚动轴承的刚度参数.振动工程学报,2004,17(4):388-392.
[15] S.ZIAEI-RAD.Finite Element Model Updating of Rotating Structures Using Different Optimisation Techniques. Iranian Journal of Science & Technology, 2005,29(B6): 569-585.
[16] S.Audebert,T.Chapron,A.C.Leger,et al.Multi-bearing Rotor Model Updating using Experimental Modal and Response Data.Proceedings of the 15th IMAC.Orlando,U.S.A,1997: 162-168.
[17]张令弥,张柏庆,袁向荣.特征向量导数计算各种模态法的比较和发展.应用力学学报,1994,11(3):68-74.
[18]孔翠芳,戴华.用不完全模态数据修正粘性阻尼矩阵.振动工程学报,2005, 18(1):85-90.
[19]杨杰,耿遵敏,谭雪琴.基于复模态的结构有限元动态模型修正理论.振动与冲击,2002, 21(1):30-32.
[20]蒋家尚,袁永新.基于复模态试验数据的粘性阻尼矩阵的修正.振动与冲击,2007, 26(5):74-80.
[21] Yong Lu, Zhenguo Yu.A Two-level Neural Network Approach for Dynamic FE Model Updating Including Damping.Journal of Sound and Vibration, 2004,275:931-952.
[22]冯文贤,陈新.基于试验复模态参数的有限元模型修正.航空学报,1999,20(1):11-16.
[23] H.G.Natake.Die Korrektur des Rechenmodells Eines Elastomechanischen Systems Mittels Gemessener Erzwungener Schwingungen.Ingenieur-Archiv,1977,4(6):169-184.
[24] C.D.Foster.A Method of Improving Finite Element Models by Using Experimental Data:Application and Implications for Vibration Monitoring.International Journal of Mechanical Science,1980,32(3):191-203.
[25] M.Link.Identification and Correction of Errors in Analytical Models Using Test Data:Theoretical and Practical Bounds.Proceedings of the 8th International Modal Analysis Conference,Orlando,Kissimmee,1990,570-578.
[26] Friswell,M.I.Updating Model Parameters from Frequency Domain Data Via Reduced Order Model.Mechanical Systems and Signal Processing.1990,4(5):377-391.
[27] Cottin,N.On the Parameter Identification of Elastommechanical Systems Using Input and Output Residuals.Ingenieur Archive.1984,40(2):378-387.
[28] Fritzen,C.P.Identification of Mass,Damping and Stiffness Matrices of Mechanical Systems.Journal of Vibration,Acoustics,Stress and Reliability in Design,1986,108(4):9-16.
[29] Ljung,J.System Identification.Theory for the Uses Englewood Cliffs,1987:37-40.
[30] Larsson,P.O.Model Updating Using Force Vibration Testing Using Numerical StableFormulations.Proceedings of the 10th International Model Analysis Conference,Orlando,Kissimmee,1992:966-974.
[31]徐张明,高天明,沈荣瀛,华宏星.一种改进的利用频响函数进行有限元模型修正的方法.振动与冲击,2002,21(3):43-46.
[32]徐张明,沈荣瀛,华宏星.基于频响函数相关性的灵敏度分析的有限元模型修正.机械强度,2003,25(1):5-8.
[33]秦仙蓉.基于灵敏度分析的结构计算模型修正及相关问题研究,[博士学位论文].南京:南京航空航天大学,2001.
[34]沃德海伦.模态分析理论与实验(白化同,郭继忠).北京:北京理工大学出版社,2001:20-43.
[35]董其伍.刘启玉.CAE技术回顾与展望.计算机工程与应用,2002(14):82-84.
[36]傅永华.有限元分析基础.武汉:武汉大学出版社,2003:19-96.
[37]王助成,邵敏.有限单元法基本原理和数值方法.北京:清华大学出版社,1997:43-82.
[38]杨剑,张璞,陈火红.新编MD NASTRAN有限元实例教程.北京:机械工业出版社,2008:13-31.
[39]李宇明,郑坚,白鸿柏.金属橡胶材料的动态力学模型.材料研究学报,2003,17(5):499-504.
[40]李宇明,彭威,白鸿柏,等.金属橡胶材料宏观和细观力学模型.机械工程学报,2005, 41(9):38-41.
[41]丁杰.一种新型的梁单元—有限元法在转子动力学中的应用.火控雷达技术,2000,29: 20-28.
[42]李冬伟,白鸿柏,杨建春,等.金属橡胶动力学建模及参数识别,振动与冲击,2005,24(6):57-60.
[43]王新,朱梓根.环形金属橡胶减振器.航空动力学报,1997,12(2):143-145.
[44]马艳红,郭宝亭,朱梓根.金属橡胶材料静态特性的研究.航空动力学报,2004,19(3):326-331.
[45]夏宇宏,闫辉,姜洪源,等.环形金属橡胶隔振器弹性参数的确定.润滑与密封,2005,5(3):34-36.
[46]闫辉,夏宇宏,姜洪源.复杂形状的金属橡胶隔振器当量弹性模量研究.湖南科技大学学报,2008,23(3):46-48.
[47]郭宝亭,朱梓根,崔荣繁,等.金属橡胶材料的理论模型研究.航空动力学报,2004,19(3):314-319.
[48]夏宇宏,姜洪源,敖宏瑞,等.汽车用环形金属橡胶弹性元件的性能研究.机械设计,2002,11(3):8-10.
[49]张芳萍,樊文欣,梁佳.金属橡胶阻尼元件的力学模型及减振特性研究.新技术新工艺,2007,(8):66-68.
[50]张保强.磁轴承-转子系统的有限元模型修正及相关问题研究,[硕士学位论文].南京:南京航空航天大学,2009.
[51]高华.金属橡胶磁悬浮轴承组合支承转子系统动力学特性研究,[硕士学位论文].南京:南京航空航天大学,2009.
[52]李效法.基于灵敏度分析的模型修正研究及其实现.[硕士学位论文].南京:南京航空航天大学,2007.
[53]费庆国.结构动态有限元模型修正技术若干关键问题的研究,[博士学位论文].南京:南京航空航天大学,2004.
[54] Johnson,Erwin H,et al.MSC.NASTRAN 2004 Design Sensitivity and Optimization User’s Guide.MSC.Software,Santa Ana,CA,2003:103-105.
[55] Sondipon Adhikari.Rates of change of eigenvalues and eigenvectors in damped dynamic system.AIAA Journal,1999,37 (11):1452-1458.
[56]傅志方,华宏星.模态分析理论与应用.上海:上海交通大学出版社,2000:183-184.
[57]袁爱民.基于灵敏度分析的有限元模型修正技术若干关键问题研究,[博士学位论文].南京:东南大学,2006.
[58] A.W.Lees,J.K.Sinha,M.I.Friswell,Model-based Identification of Rotating Machines.Mechanical Systems and Signal Processing,2009,(23):1884–1893.
[59]隋允康,杜家政,彭细荣.MSC.Nastran有限元动力分析与优化设计使用教程.北京:科学出版社,2004:3-10.
[60]李海涛,邓樱.MATLAB程序设计教程.北京:高等教育出版社,2002:2-8.
[61]朱凼凼,冯咬齐,向树红.基于频率响应函数的动力学模型修正方法研究.中国工程科学, 2005,(8):89-94.
[62] Kye-Si,Kwon1,Rong-Ming Lin.Frequency Selection Method for FRF-Based Model Updating.Journal of Sound and Vibration,2004,(278):285–306.
[63] Rodrigo Pascual,Roberto Schalchli,Mario Razeto.Damping Identification Using a Robust FRF-Based Model Updating Technique.Proceedings of the XXI International Modal Analysis Conference,Kissimmee,2003:1-14.
[64] D.J.Ewins.Modal Testing Theory and Practice.England:Research Studies Press,1984:153-156.
[65]许本文,焦群英.机械振动与模态分析基础.北京:机械工业出版社,1998:23-28.
[66]《N-Modal模态分析软件用户手册V4.0版》,南京航空航天大学振动工程研究所,2008.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |