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- [31] Optical Frequency Transfer with a 1284 km Coherent Fiber Link2014 EUROPEAN FREQUENCY AND TIME FORUM (EFTF), 2014, : 1 - 4Calonico, D.论文数: 0 引用数: 0 h-index: 0机构: INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyBertacco, E. K.论文数: 0 引用数: 0 h-index: 0机构: INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyCalosso, C.论文数: 0 引用数: 0 h-index: 0机构: INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyClivati, C.论文数: 0 引用数: 0 h-index: 0机构: INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyGodone, A.论文数: 0 引用数: 0 h-index: 0机构: INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyFrittelli, M.论文数: 0 引用数: 0 h-index: 0机构: INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyMura, A.论文数: 0 引用数: 0 h-index: 0机构: INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyZucco, M.论文数: 0 引用数: 0 h-index: 0机构: INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyLevi, F.论文数: 0 引用数: 0 h-index: 0机构: INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyCostanzo, G. A.论文数: 0 引用数: 0 h-index: 0机构: Politecn Torino, Dept Elect, Turin, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyPoli, N.论文数: 0 引用数: 0 h-index: 0机构: Univ Firenze, LENS, Sesto Fiorentino, FI, Italy INFN, Sesto Fiorentino, FI, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalySutyrin, D. V.论文数: 0 引用数: 0 h-index: 0机构: Univ Firenze, LENS, Sesto Fiorentino, FI, Italy INFN, Sesto Fiorentino, FI, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, ItalyTino, G. M.论文数: 0 引用数: 0 h-index: 0机构: Univ Firenze, LENS, Sesto Fiorentino, FI, Italy INFN, Sesto Fiorentino, FI, Italy INRIM, Ist Nazl Ric Metrol, Opt Div, Turin, Italy
- [32] Analysis and Reduction of Nonlinear Effects in Optical Fiber Frequency TransferAPPLIED SCIENCES-BASEL, 2023, 13 (23):Gao, Jing论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R ChinaZhang, Linbo论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R ChinaJiao, Dongdong论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R ChinaXu, Guanjun论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R ChinaBu, Jiayu论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R ChinaWu, Mengfan论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R ChinaZang, Qi论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R ChinaZhang, Xiang论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R ChinaDong, Ruifang论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R ChinaLiu, Tao论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R ChinaZhang, Shougang论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, 3 East Shuyuan Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 East Shuyuan Rd, Xian 710600, Peoples R China
- [33] Femtosecond-Level Frequency Transfer at 10 GHz over Long Fiber Link with Optical-Electronic Joint CompensationAPPLIED SCIENCES-BASEL, 2022, 12 (21):Huang, Wantao论文数: 0 引用数: 0 h-index: 0机构: Guangzhou Univ, Math & Informat Sci, Guangzhou 510006, Peoples R China Kaili Univ, Coll Sci, Kaili 556099, Peoples R China Guangzhou Univ, Math & Informat Sci, Guangzhou 510006, Peoples R ChinaLi, Yang论文数: 0 引用数: 0 h-index: 0机构: Inst Southwestern Commun, Sci & Technol Commun Secur Lab, Chengdu 610041, Peoples R China Guangzhou Univ, Math & Informat Sci, Guangzhou 510006, Peoples R ChinaZhang, Peng论文数: 0 引用数: 0 h-index: 0机构: Univ Elect Sci & Technol China, Sch Automat Engn, Chengdu 611731, Peoples R China Guangzhou Univ, Math & Informat Sci, Guangzhou 510006, Peoples R ChinaFang, Lujun论文数: 0 引用数: 0 h-index: 0机构: Univ Elect Sci & Technol China, Sch Automat Engn, Chengdu 611731, Peoples R China Guangzhou Univ, Math & Informat Sci, Guangzhou 510006, Peoples R ChinaHou, Dong论文数: 0 引用数: 0 h-index: 0机构: Univ Elect Sci & Technol China, Sch Automat Engn, Chengdu 611731, Peoples R China Guangzhou Univ, Math & Informat Sci, Guangzhou 510006, Peoples R China
- [34] Optical frequency transfer via a 660 km underground fiber link using a remote Brillouin amplifierOPTICS EXPRESS, 2014, 22 (22): : 26537 - 26547Raupach, S. M. F.论文数: 0 引用数: 0 h-index: 0机构: Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany Phys Tech Bundesanstalt, D-38116 Braunschweig, GermanyKoczwara, A.论文数: 0 引用数: 0 h-index: 0机构: Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany Phys Tech Bundesanstalt, D-38116 Braunschweig, GermanyGrosche, G.论文数: 0 引用数: 0 h-index: 0机构: Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany
- [35] Optical coherence transfer over 50-km spooled fiber with frequency instability of 2x1017 at 1 sCHINESE PHYSICS B, 2015, 24 (08)Ma Chao-Qun论文数: 0 引用数: 0 h-index: 0机构: E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R China E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R ChinaWu Li-Fei论文数: 0 引用数: 0 h-index: 0机构: E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R China E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R ChinaJiang Yan-Yi论文数: 0 引用数: 0 h-index: 0机构: E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R China E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R ChinaYu Hong-Fu论文数: 0 引用数: 0 h-index: 0机构: E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R China E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R ChinaBi Zhi-Yi论文数: 0 引用数: 0 h-index: 0机构: E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R China E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R ChinaMa Long-Sheng论文数: 0 引用数: 0 h-index: 0机构: E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R China E China Normal Univ, State Key Lab Precis Spect, Shanghai 200062, Peoples R China
- [36] Over 40-W Electric Power and Optical Data Transmission Using an Optical FiberIEEE TRANSACTIONS ON POWER ELECTRONICS, 2021, 36 (04) : 4532 - 4539Matsuura, Motoharu论文数: 0 引用数: 0 h-index: 0机构: Univ Electrocommun, Grad Sch Informat & Engn, Chofu, Tokyo 1828585, Japan Univ Electrocommun, Grad Sch Informat & Engn, Chofu, Tokyo 1828585, JapanNomoto, Hayato论文数: 0 引用数: 0 h-index: 0机构: Univ Electrocommun, Grad Sch Informat & Engn, Chofu, Tokyo 1828585, Japan Univ Electrocommun, Grad Sch Informat & Engn, Chofu, Tokyo 1828585, JapanMamiya, Hikaru论文数: 0 引用数: 0 h-index: 0机构: Univ Electrocommun, Grad Sch Informat & Engn, Chofu, Tokyo 1828585, Japan Univ Electrocommun, Grad Sch Informat & Engn, Chofu, Tokyo 1828585, JapanHiguchi, Tadanobu论文数: 0 引用数: 0 h-index: 0机构: Univ Electrocommun, Grad Sch Informat & Engn, Chofu, Tokyo 1828585, Japan Univ Electrocommun, Grad Sch Informat & Engn, Chofu, Tokyo 1828585, JapanMasson, Denis论文数: 0 引用数: 0 h-index: 0机构: Broadcom, IFPD Div, Ottawa, ON K1A 0R6, Canada Univ Electrocommun, Grad Sch Informat & Engn, Chofu, Tokyo 1828585, JapanFafard, Simon论文数: 0 引用数: 0 h-index: 0机构: Broadcom, IFPD Div, Ottawa, ON K1A 0R6, Canada Univ Electrocommun, Grad Sch Informat & Engn, Chofu, Tokyo 1828585, Japan
- [37] Coherent phase transfer via fiber using heterodyne optical phase locking as optical amplificationAPPLIED OPTICS, 2018, 57 (32) : 9620 - 9624Deng, Xue论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R China Univ Chinese Acad Sci, Beijing 100039, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R ChinaLiu, Jie论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R ChinaZang, Qi论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R ChinaJiao, Dongdong论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R China Univ Chinese Acad Sci, Beijing 100039, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R ChinaGao, Jing论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R ChinaZhang, Xiang论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R ChinaWang, Dan论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R ChinaDong, Ruifang论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R ChinaLiu, Tao论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Stand, Xian 710600, Shaanxi, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, Xian 710600, Shaanxi, Peoples R China
- [38] High Precision Time and Frequency Integration Transfer via Optical FiberJOURNAL OF ELECTRONICS & INFORMATION TECHNOLOGY, 2019, 41 (07) : 1579 - 1586Yang Wenzhe论文数: 0 引用数: 0 h-index: 0机构: Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R China Sci & Technol Metrol & Calibrat Lab, Beijing 100854, Peoples R China Second Acad China Aerosp, Beijing 100854, Peoples R China Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R ChinaYang Honglei论文数: 0 引用数: 0 h-index: 0机构: Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R China Sci & Technol Metrol & Calibrat Lab, Beijing 100854, Peoples R China Second Acad China Aerosp, Beijing 100854, Peoples R China Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R ChinaWang Xueyun论文数: 0 引用数: 0 h-index: 0机构: Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R China Sci & Technol Metrol & Calibrat Lab, Beijing 100854, Peoples R China Second Acad China Aerosp, Beijing 100854, Peoples R China Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R ChinaZhang Shengkang论文数: 0 引用数: 0 h-index: 0机构: Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R China Sci & Technol Metrol & Calibrat Lab, Beijing 100854, Peoples R China Second Acad China Aerosp, Beijing 100854, Peoples R China Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R ChinaZhao Huan论文数: 0 引用数: 0 h-index: 0机构: Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R China Sci & Technol Metrol & Calibrat Lab, Beijing 100854, Peoples R China Second Acad China Aerosp, Beijing 100854, Peoples R China Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R ChinaYang Jun论文数: 0 引用数: 0 h-index: 0机构: Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R China Sci & Technol Metrol & Calibrat Lab, Beijing 100854, Peoples R China Second Acad China Aerosp, Beijing 100854, Peoples R China Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R ChinaFeng Keming论文数: 0 引用数: 0 h-index: 0机构: Second Acad China Aerosp, Beijing 100854, Peoples R China Beijing Inst Radio Metrol & Measurement, Beijing 100854, Peoples R China
- [39] Brillouin amplification supports 1 x 10-20 uncertainty in optical frequency transfer over 1400 km of underground fiberPHYSICAL REVIEW A, 2015, 92 (02):Raupach, Sebastian M. F.论文数: 0 引用数: 0 h-index: 0机构: Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany Phys Tech Bundesanstalt, D-38116 Braunschweig, GermanyKoczwara, Andreas论文数: 0 引用数: 0 h-index: 0机构: Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany Phys Tech Bundesanstalt, D-38116 Braunschweig, GermanyGrosche, Gesine论文数: 0 引用数: 0 h-index: 0机构: Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany
- [40] High-Precision Time-Frequency Signal Simultaneous Transfer System via a WDM-Based Fiber LinkPHOTONICS, 2021, 8 (08)论文数: 引用数: h-index:机构:论文数: 引用数: h-index:机构:论文数: 引用数: h-index:机构:论文数: 引用数: h-index:机构:论文数: 引用数: h-index:机构:Xue, Wenxiang论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 Shuyuandong Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Primary Stand, 3 Shuyuandong Rd, Xian 710600, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 Shuyuandong Rd, Xian 710600, Peoples R ChinaChen, Faxi论文数: 0 引用数: 0 h-index: 0机构: Xidian Univ, Sch Aerosp Sci & Technol, 2 Taibainan Rd, Xian 710071, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 Shuyuandong Rd, Xian 710600, Peoples R ChinaLiu, Tao论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 Shuyuandong Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Primary Stand, 3 Shuyuandong Rd, Xian 710600, Peoples R China Univ Chinese Acad Sci, 19 Yuquan Rd, Beijing 100049, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 Shuyuandong Rd, Xian 710600, Peoples R ChinaDong, Ruifang论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 Shuyuandong Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Primary Stand, 3 Shuyuandong Rd, Xian 710600, Peoples R China Univ Chinese Acad Sci, 19 Yuquan Rd, Beijing 100049, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 Shuyuandong Rd, Xian 710600, Peoples R ChinaZhang, Shougang论文数: 0 引用数: 0 h-index: 0机构: Chinese Acad Sci, Natl Time Serv Ctr, 3 Shuyuandong Rd, Xian 710600, Peoples R China Chinese Acad Sci, Key Lab Time & Frequency Primary Stand, 3 Shuyuandong Rd, Xian 710600, Peoples R China Univ Chinese Acad Sci, 19 Yuquan Rd, Beijing 100049, Peoples R China Chinese Acad Sci, Natl Time Serv Ctr, 3 Shuyuandong Rd, Xian 710600, Peoples R China