用户名: 密码: 验证码:
双频磁绝缘线振荡器的理论与实验研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
双频磁绝缘线振荡器(Bifrequency Magnetically Insulated Transmission LineOscillator,BFMILO)是一种低阻抗正交场高功率微波器件,它不仅具有磁绝缘线振荡器的优点,还具有能够稳定地同时输出两个频率的高功率微波(HPM)的特点,同时,能够产生稳定输出的双频HPM器件是一个新兴的研究方向,将具有重要的学术价值和实际应用,目前尚未见到相关报道。因此,论文提出了BFMILO的设想,建立了BFMILO的模型,开展了理论分析、粒子模拟,优化设计出了L波段BFMILO,并开展了原理性实验研究,从理论和实验上验证了产生稳定输出双频率HPM的BFMILO的可行性。同时,论文还对BFMILO的相关技术以及其它双频及多频高功率微波器件进行了初步的研究。
     论文主要研究内容包括以下几个方面:
     1.介绍了HPM研究背景,MILO的基本原理及国内外发展现状,进而阐述了BFMILO的研究意义。
     2.提出了通过在旋转对称的常规单频率MILO内部设置谐振腔深度的角向分区来实现双频率HPM输出的思想,建立了BFMILO的物理模型,分析了BFMILO的工作原理和工作特点,开展了L波段BFMILO的设计;并采用数值计算的方法研究了L波段BFMILO的高频特性,得到了BFMILO的冷腔的谐振频率,场分布,Q值等信息,分析结果表明:谐振腔深度的角向分区分别对应着BFMILO的两个工作频率,角向分区的谐振腔可以分区工作。
     3.采用三维粒子模拟程序对BFMILO进行了数值模拟研究与优化设计,研究了输出微波功率以及输出微波频率与输入电压的关系,以及微波的频谱特性;并研究了角向分区不同比例的BFMILO的微波产生特性,得到了热腔条件下的微波场分布,电子的相空图,输出微波的总功率和微波频率的变化等特性。在电子束电压为530 kV,电流为45.5 kA的条件下,所优化设计出的L波段BFMILO输出的双频微波信号频率分别为1.28GHz和1.50 GHz,周期平均功率约为2.65 GW,功率效率约为11%,两个频率谱的幅度相差约0.4 dB。粒子模拟研究进一步揭示了BFMILO内束-波互作用分区工作的规律。
     4.开展了L波段BFMILO的实验研究,建立了L波段BFMILO的实验系统和测量系统,开展了二极管与阴极材料的发射特性研究,热测试了BFMILO的辐射方向图,通过辐射场功率密度积分得到了微波的总功率,首次得到了稳定的双频率的L波段BFMILO。在电子束电压约为420 kV,管电流约为34 kA的条件下,L波段BFMILO输出的双频HPM的频率分别为1.26GHz和1.45GHz,对应的微波功率分别为398MW和222MW。实验结果验证了BFMILO产生稳定的双频HPM的可行性,为双频HPM器件研究初步探索了一个新方向。
     5.开展其它结构的双频和多频HPM器件的尝试性研究,进一步拓展了双频微波器件的研究内容。
Magnetically Insulated Transmission Line Oscillator (MILO) is a kind of cross-field device, which can generate High Power Microwave (HPM) without external magnetic field. Bifrquency Magnetically Insulated Transmission Line Oscillator (BFMILO) is a variation of that device which can generate HPM with two stable and separate frequencies, named bifrequency. This is a newly developing direction of HPM devices. A novel idea of BFMILO is put forward for the first time, and the model of BFMILO is built. An L-band BFMILO is theoretically analyzed and simulated by Particle-In-Cell (PIC) codes, and it is optimized, designed and experimented. In addition, some technologies relating to BFMILO and other bifrequency and multi-frequency HPM devices are also preliminarily investigated. The main research contents include:
     Firstly, the investigation background of HPM, the principle of MILO and the actual state of MILO investigation in the world are introduced. Then, the value of BFMILO investigation is explained.
     Secondly, a novel method of dividing a single device into different azimuthal partition to generate HPM with two frequencies is put forward for the first time in this paper. Resorting to the azimuthal partition of cavity-depth, a novel HPM device of BFMILO is put forward. The operation principle and character of BFMILO are analyzed, and an L-band BFMILO is designed. By the method of numerical calculation, the high-frequency characteristics of BFMILO are investigated, the information such as the eigen-frequencies, field distribution, Q-value of BFMILO's resonating cavities, is obtained. The analyses show that the two different azimuthal partitions are related to two different operation frequencies of BFMILO respectively, and those two azimuthal partitions of the resonating cavities in BFMILO can operate independently.
     Thirdly, BFMILO is simulated, optimezed and designed taking the method of three-dimensional PIC simulation. The relationship between output microwave power and input voltage, output microwave frequencies and input voltage, are investigated. The spectra of microwave power and fields are also analyzed. Moreover, microwave generation characteristics of BFMILOs with different azimuthal-partition proportion are investigated, the information such as microwave field distritution in the hot cavities, particles in phase space, total output microwave power and spectra, is obtained. When the electron beam voltage is 530 kV and current is about 45.5 kA, a BFMILO can generate about 2.65 GW of HPM with two stable and separate frequencies. They are respectively 1.28 GHz and 1.50 GHz. The power conversion efficiency is about 11%. The amplitude difference of the spectrum between the two frequencies is about 0.4dB. The results confirm the rule that the interaction between electron beam and microwave in BFMILO is separately in different perticular partition once again.
     Fourthly, a preliminary experiment of L-band BFMILO is carried out. Experimental system and measurement system are built. Measurement and calibration method are introduced. The diode of BFMILO and the emission characteristics of different cathode materials are also investigated. Far-field patterns of the antenna of L-band BFMILO are obtained, and the total microwave power is obtained by integral of power density of radiation field. FFT of the radiated microwave signal gives out two stable frequencies, which indicates an L-band BFMILO is developed successfully. Employing an electron beam of 420 kV , 34kA, an L-band BFMILO can generate HPM with two stable and separate frequencies. They are respectively 1.26 GHz and 1.45 GHz with respective microwave power of 398 MW and 222 MW. The results prove the feasibility that BFMILO can generate bifrequency HPM.
     Eventually, some other bifrequency and multi-frequency HPM devices are investigated. They might exploit the investigation of bifrequency microwave devices.
引文
1 Benford James,Swegle John.High Power Microwave[M].Arech House,Norwood,MA,1991
    2 Benford J,Swedle J.高功率微波[M],中译本.成都:电子科技大学出版社,1992.1-49,307-334.
    3 Barker R J,Schamiloglu E.高功率微波源与技术[M],中译本.北京:清华大学出版社,2001.1-36,423-452.
    4 Granatstein L,Alereff I.High power microwaves sources[M].Boston:Artech House,1987.1-99,441-562.
    5 周传明,刘国治,刘永贵,等.高功率微波源[M].原子能出版社,1997.
    6 廖为民,董志伟,周海京.从DETAR合同的签署看美国高功率微波武器技术研究的现状[J].高功率微波进展,2005,4(2):1-6.
    7 王弘刚.调制型虚阴极振荡器的研究[D].博士学位论文.长沙:国防科学技术大学,2004.
    8 罗雄,廖成,孟凡宝等.同轴虚阴极谐振效应研究[J].物理学报,2006,55(11):5774-5778.
    9 陈代兵,刘庆想,何琥等.X波段五腔渡越管振荡器的理论与实验研究[D].硕士学位论文,中国工程物理研究院,2002.
    10 范植开.渡越管振荡器的理论研究与原理性实验[D].博士学位论文,北京:中国工程物理研究院,1999.
    11 何琥.X波段六腔渡越管振荡器的理论和实验研究[D].博士学位论文.北京:中国工程物理研究院北京研究生部,2003.
    12 崔学芳.C波段双间隙输出腔的理论分析和实验研究[D].硕士学位论文,北京:中国工程物理研究院,2000.
    13 黄华.S波段长脉冲相对论速调管放大器的理论和实验研究[D].博士学位论文.北京:中国工程物理研究院,2006.
    14 张晓萍.新型磁绝缘线振荡器的研究[D].博士学位论文.长沙:国防科学技术大学,2004.
    15 樊玉伟.紧凑型L波段磁绝缘线振荡器的研究[D].硕士学位论文.长沙:国防科学技术大学,2003.
    16 刘松.磁绝缘线振荡器的研究[D].博士学位论文.长沙:国防科学技术大学,2001.
    17 郭焱华.C波段磁绝缘线振荡器的理论与实验研究[C].硕士学位论文.绵阳:中国工程物理研究院:2005.
    18 Friedman M,Serlin V,Lau Y.Relativistic klystron amplifier Ⅰ[A]:high power operation.Intense microwave and particle beams Ⅱ[A],Proceeding SPIE.1991,1407:20-25.
    19 Bugaev S P,Cherepenin V A,Kanavets V I,et al.Relativistic multiwave Cerenkov Generators[J].IEEE Trans.Plas.Sci.1990,18(3):525-536.
    20 Bugaev S P,Cherepenin V A,Kanavets V I,et al.Investigation of a millimeter-wavelength-range Relativistic Diffraction Generator[J].IEEE Trans.Plas.Sci.1990,18(3):518-524.
    21 Lemke R W,Clark M C.Theory and simulation of high-power microwave generation in a magnetically insulated transmission line oscillator[J].J.Appl.Phys.1987,62(8):3436-3440.
    22 Clark M C,Marder B M,Bacon L D.Magnetically insulated transmission lines oscilletor[J].Appl.Phys.Lett.1988,52(1):78-80.
    23 Marder B M.Simulated Behavior of the Magnetically insulated Oscillator[J].J.Appl.Phy.1989,65:1338.
    24 Lemke R W,DeMuth G E,Biggs A W.Theoretical and experimental investigation of axial power extraction from a magnetically insulated transmission line oscillator[A].Proc.SPIE,vol.1226.Intense Microwave and Particle Beams[C],Los Angles,CA,Jan.1990:199-208.
    25 Voss D E,et al.Experimental study of a self-magnetically insulated high power microwave cross-field oscillator device.AFWL-TR-88-32,Air Force Weapons Lab.,Kirland AFB,NM,Nov.,1988.
    26 Calico S E,Clark M C,Lemke R W,et al.Experimental and theoretical investigation of a magnetically insulated line oscillator(MILO)[A].Proc.SPIE.1995,2557:50-59.
    27 Lemke R W,Calico S E,Clark M C.Investigation of a load-limited,magnetically insulated transmission line oscillator(MILO)[J].IEEE Trans.Plasma Sci.1997,25(2):364-373.
    28 Hendricks K,Haworth M D,Ferguson P,et al.Upgrades to a 600-ns multigigawatt RKO[J].IEEE Int.Conf.Plasma Science.1998:187.
    29 Eastwood J W,Hawkins K C,Hook M P.The Tapered MILO[J].IEEE Trans.Plasma Sci.1998,26:698-713.
    30 张晓萍,钟辉煌等.利用负载电流产生微波的新型MILO[J].强激光与粒子束,2003,15(1):80-84.
    31 杨祥林.微波器件原理[M].北京:电子工业出版社,1985.
    32 王冬,范植开,陈代兵等.双阶梯阴极型磁绝缘线振荡器设计与模拟[J].强激光与粒子束,2007,19(4):647-650.
    33 陈代兵,范植开,周海京,等.L波段硬管磁绝缘线振荡器的研制[J].强激光与粒子束,2007,19(8):1352-1356
    34 Bekefi G,Orzechowski T J.Proceedings of the 1 st International Pulsed Power Conference[C].Lubbock,TX,9-11,November 1976.
    35 Davis H A,Fulton R D,Sherwood E G.Esistively loaded MILO experiments.Los Alamos Nat.Lab.,Los Alamos,NM,LA-UR-89-1199,Mar,1989.
    36 Haworth M D,Baca G,Benford J N,et al.Significant Pulse-Lengthening in a Multi-gigawatt Magnetically Insulated Transmission Line Oscillator[J].IEEE Trans.Plasma Sci.1998,26(3):312-319.
    37 Haworth M D,Luginsland J W,Lemke R W.Evidence of a new pulse-shortening mechanism in a load-limited MILO[J].IEEE Trans.Plasma Sci.2000,28:511-516.
    38 Haworth M D,Englert T J,Hendricks K J,et al.A comprehensive diagnostic suite for MILO[J].Rev.Sci.Instrum.2000,71:1539-1547.
    39 Haworth M D,Luginsland J W,Lemke R W.Improved cathode design for long-pulse MILO operation[J].IEEE Trans.Plasma Sci.2001,29:388-392.
    40 Haworth M D,Cartwright K L,Luginsland J W,et al.Improved Electrostatic Design for MILO Cathodes[J].IEEE Trans.Plasma Sci.2002,30:992-997.
    41 Ashby D E T F,Eastwood J W,Allen J,et al.Comparison between Experiment and Computer Modeling for Simple MILO Configurations[J].IEEE Trans.Plasma Sci.1995,23:959-969.
    42 杨郁林,丁武.MILO物理分析与数值模拟[J].强激光与粒子束,1999,11(5):623-627.
    43 杨郁林,丁武.高频大功率磁绝缘线振荡器的理论设计[J].强激光与粒子束,2001,13(1):76-78.
    44 孙会芳,董志伟等.MILO实验模型的频移问题研究[J].信息与电子工程,2004,2(2):95-97.
    45 孙会芳,董志伟等.改进型磁绝缘线振荡器的设计和数值模拟[J].强激光与粒子束,2001,13(1):93-96.
    46 丁武.磁绝缘线振荡器中空间电荷的调制[J].强激光与粒子束,2001,13(2):213-218.
    47 丁武.磁绝缘线振荡器中空间电荷的辐射[J].强激光与粒子束,2002,14(1):743-748.
    48 Hao Jianhong,Ding Wu.The chaotic behavior of the radiation field in the Magnetically insulated transmission line oscillator[J].Phys.Rev.E.2003,67(2):
    49 Qian B L,Liu Y G et al.Two-dimensional analysis of the relativistic para-potential electron flow in a magnetically insulated line oscillator(MILO)[J].IEEE Trans.Plasma Sci.2000,28:760-766.
    50 陈代兵,范植开,周海京,等.L波段硬管磁绝缘线振荡器的研制[J].强激光与粒子束,2007,19(8):1352-1356.
    51 王晓东,范植开,孟凡宝等.虚阴极振荡器“硬管化”实验研究[J].强激光与粒子束,2006,18(6):969-971.
    52 Haworth M D,Allen K,Baca G et al.Recent progress in the Hard-Tube MILO experiment[A].Proc.SPIE,1997,3158:28-39.
    53 张晓萍,钟辉煌等.利用负载电流产生微波的新型MILO[J].强激光与粒子束,2003,15(1):80-84.
    54 樊玉伟.紧凑型L波段磁绝缘线振荡器的研究[D].硕士学位论文.长沙:国防科学技术大学,2003.
    55 Chen D B,Fan Z K,Dong Z W,et al.Experimental researches on ladder cathode MILO[C].Proceedings of The First Euro-Asian Pulsed Power Conference(EAPPC'06),Chengdu,2006:Thu-O13.
    56 陈代兵,范植开,董志伟等.阶梯阴极型L波段MILO的实验研究[J].强激光与粒子束,2007,19(5):820-824
    57 王冬,范植开,陈代兵等.双阶梯阴极型磁绝缘线振荡器设计与模拟[J].强激光与粒子束,2007,19(4):647-650.
    58 樊玉伟,钟辉煌,郑世勇等.X波段磁绝缘线振荡器的模拟研究[J].强激光与粒子束,2006,18(3):439-442.
    59 靳振兴,张晓萍,钱宝良.P波段混合型MILO的粒子模拟研究[A].第十届高功率粒子束学术交流会[C].长沙,2006:391-395.
    60 王冬,范植开,陈代兵,等.S波段磁绝缘线振荡器的数值模拟[J].强激光与粒子束,2007,19(11):
    61 孙会芳,董志伟,周海京等.虚阴极为负载的磁绝缘线振荡器设计和研究[J].强激光与粒子束,2005,17(8):1126-1128.
    62 邵福球.等离子体粒子模拟[M].北京,科学出版社,2002,1-14.
    63 陈代兵,周海京,范植开等.C波段MILO输出微波的模式诊断[J].强辐射技术与应用,2005,4(4):52-61.
    64 李天明,李家胤,孙大瑞等.S波段可调谐相对论磁控管的初步设计[J].强激光与粒子束,2004,16(3):325-320.
    65 陈代兵,孟凡宝,王冬,等.双频磁绝缘线振荡器的粒子模拟[J].高功率微波技术,2007,15(2):1-7
    66 陈代兵,孟凡宝,王冬,等.L波段双频磁绝缘线振荡器的粒子模拟[A].四川省电子学会高能电子学专业委员会第五届学术交流会论文集[C],银川 2007.10.
    67 陈代兵,王冬,范植开,等.多频磁绝缘线振荡器的粒子模拟[J].强激光与粒子束,2007,19(10):1702-1708.
    68 张晓萍,钟辉煌等.磁绝缘线振荡器同轴慢波结构色散特性分析[J].强激光与粒子束,2004,16(3):363-366.
    69 刘松.磁绝缘线振荡器的研究[D].博士学位论文.长沙:国防科学技术大学,2001.
    70 Wang Dong,Fan Zhikai,Chen Daibing,et al.Rigorous analysis of the coaxial disk-loaded waveguide slow-wave structures[A].The 5th international conference on microwave and millimeter wave technology proceedings[C].Guilin,China,2007:591-594.
    71 Wang Dong,Fan Zhikai,Chen Daibing,et al.Investigation of dispersion characteristics in coaxial disk-loaded slow-wave structures with both symmetric and asymmetric modes[J].IEEE Trans.Plasma Sci.To be published.
    72 Minami K,Carmel Y,Granatstein V L,et al.Linear theory of electromagnetic wave generation in a plasma-loaded corrugation-wall resonator[J].IEEE Trans.Plasma Sci.1990,18(3):537-545.
    73 Minami K,Saito M,Choyal Y,et al.Linear dispersion relation of backward-wave oscillators with finite-strength axial magnetic filed[J].IEEE Trans.Plasma Sci.2002,30(3):1134-1146.
    74 Swegel J A,Poukey W,Leifeste G T.Back-ward wave oscillators with rippled wall resonators:Analytic theory and numerical simulation[J].Phys.Fluids.1985,28(9):2882-2894.
    75 Wang Haoying,Yang Ziqiang,Zhao Linxin,Liang Zheng.Numerical Computation of Dispersion Curves for Symmetric and Asymmetric Modes in an Arbitrary Cylindrical Metal SWS[J].IEEE Trans.Plasma Sci.2005,33(1):111-118.
    76 何琥.C波段磁绝缘线振荡器的开放腔高频特性分析[J].强辐射技术与应用,2006,18(1):101-104.
    77 陈代兵,何琥,刘庆想.X波段五管渡越管振荡器的高频特性研究[J].强激光与粒子束,2003,15(10):1003-1006.
    78 何琥,刘庆想.X波段六管渡越管振荡器的高频特性研究[J].强激光与粒子束.2004,16(4):481-484.
    79 杨祥林.微波器件原理[M].北京:电子工业出版社,1985.
    80 Zhang Keqian,Li Deji.Electromagnetic Theory for Microwaves and Optoelectronics[M].Beijing:Publishing House of Electronics Industry,2001.286-289,392-395.
    81 Zhang Keqian,Li Deji.Electromagnetic Theory for Microwave and Optical Devices[M].Berlin Heidelberg:Springler-Verlag,1998.
    82 Zhang Yong,Mo Yuanlong,Zhou Xiaolan.Rigorous analysis of the disk-loaded waveguide slow-wave structures[J].Int.J.Infrared Millim.Waves.2003,24(4):525-535.
    83 #12
    84 徐福锴,丁武.一种柱-锥盘荷波导的色散关系[J].强激光与粒子束,2003,15(2):180-183.
    85 王冬,邢庆子,黄峰等.渐变型磁绝缘线振荡器色散关系的研究[J].强激光与粒子束,2006,18(4):623-626.
    86 陈代兵,刘庆想,何琥,等.X波段五腔渡越管振荡器的理论与实验研究[J].强激光与粒子束,2005,17(1):93-98
    87 Tarakanov V P.User Manual of Code KARAT.1998.
    88 余国芬.功能强大的电磁粒子模拟程序-MAGIC及其应用介绍[J].电子科技导报,1997,2:27-29.
    89 Hurtig T,Moller C,Larsson A,et al.Numerical simulation of direct extraction of the TE_(11) mode in a coaxial vircator[A].Proc of EAPPC.Chengdu,China,2006.
    90 雷朝军,喻胜,鄢然等.PIC数值模拟中的输出功率提取探讨[A].第十届高功率粒子束学术交流会议论文集[C].长沙,2006:190-193.
    91 Mendel C W,Jr.And Rosenthal.Modeling magnetically insulated devices using flow impedance[J].Phys.Plasmas 2.1995:1332-1342.
    92 张章.高功率微波源中脉冲缩短现象的粒子模拟与机理研究[D].硕士学位论文.成都:电子科技大学,2004.
    93 王冬,陈代兵,范植开等.L波段MILO低真空下工作特性的粒子模拟与实验研究[J].强激光与粒子束,2007,19(5):793-798.
    94 张克潜,李德杰.微波与光电子学中的电磁理论[M].北京:电子工业出版社,1994.
    95 谢处方,饶克谨.电磁场与电磁波[M],第二版.北京:高等教育出版社,1998:235-237.
    96 黄宏嘉.微波原理[M],卷一.北京:科学出版社,1963.
    97 米勒.强流带电粒子束物理学导论[M].中译本.北京:原子能出版社,1990.
    98 舒挺,王勇.高功率微波的远场测量[J].强激光与粒子束,2003,15(5):485-488.
    99 宁辉,王宏军等.HPM外场实验中空间辐射测量[A].全国第五届高功率微波学术研讨会论文集[C].珠海:2002.
    100 陈代兵,范植开,黄华等.X波段高功率微波辐射场功率测量系统的标定[J].强辐射技术与应用,2004,3(2):33-37.
    101 刘庆想,袁成卫.一种新型同轴TEM-圆波导TE_(11)模式变换器[J].强激光与粒子束,2004,16(11):1421-1424.
    102 袁成卫,刘庆想,钟辉煌.大尺寸模式转换天线的设计与实验研究[J].强激光与粒子束,2005,17(9):1405-1408.
    103 刘克成,宋学诚.天线原理[M].长沙:国防科学技术大学出版社,1989.
    104 张福顺,张进民.天线测量[M].西安:西安电子科技大学出版社,1995.
    105 陈代兵,范植开等.开口波导有效接收面积的测量[J].强激光与粒子束,2004,16(4):474-476.
    106 陈代兵,周海京,刘庆想 等.圆波导斜劈辐射天线的实验研究[J].强激光与粒子束,2002,14(4):595-598.
    107 Daibing Chen,Haijing Zhou,Qingxiang Liu,etc.EXPERIMENTAL RESEARCHES ON A CIRCULAR WAVEGUIDE BEVEL CUT RADIATION ANTENNA[A].Proceedings of 2003Asia-Pacific Microwave Conference(APMC'03)[C],Seoul,Korea,2003
    108 陈代兵,范植开,周海京,等.L波段磁绝缘线振荡器一体化辐射天线[J].强激光与粒子束,2008,20(3):435-438
    109 邢庆子.向内发射同轴虚阴极振荡器的研究[D].博士后研究报告.北京:清华大学,2006.
    110 殷毅,杨建华等.温度对水电阻分压器影响的实验研究[A].全国第六届高功率微波学术研讨会[C].2004.
    111 胡海鹰,李旭东,陈代兵等.X波段渡越管振荡器频谱诊断[J].强激光与粒子束,2002,14(3):445-448.
    112 刘国治,黄文华,王宏军.单次短脉冲微波频率分析系统-环流波导色散线[J].强激光与粒子束,1999,11(2):234-238.
    113 陈代兵,范植开,孟凡宝等.一种基于热离子二极管的大功率微波探测器[J].强激光与粒子束,2006,18(5):871-875
    114 J.H.Booske,W.W.Destler,Z.Segalov,et al.Propagation of Wiggler focused relativistic sheet electron beams[J],J.Appl.phys.1988,64(6):6-11
    115 J.H.Booske,B.D.Mcvey,T.M.Antonsen Jr.Stability and confinement of nonrelativistic sheet electron beams with periodic cusped magnetic focusing[J].J.Appl.Phys.1993,73(9):4140-4155
    116 王占亮.带状电子注不稳定性研究[D].硕士学位论文,成都:电子科技大学,2006

© 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