Publications of Prof. G.H. Chen's Research Group

1. "The Magnon Pairing Mechanism of Superconductivity in Cuprate Ceramics", Guanhua Chen, William A. Goddard III*,Science 239, 899 (1988).

2. "Superconducting Properties of Copper Oxide High-Temperature Superconductor", Guanhua Chen, Jean-Marc Langlois, Yuejin Guo, William A. Goddard III*,Proc. Nati. Acad. Sci. USA 86, 3447 (1989).

3. "Magnon-Exchange Pairing and Superconductivity", Guanhua Chen, Jean-Marc Langlois, Yuejin Guo, William A. Goddard III*,Science 243, 547 (1989).

4. "The Quantum Chemistry View of High-T Superconductors", Y. Guo, G. Chen, H. Q. Ding, J.-M. Langlois, W. A. Goddard III*,Proceedings of the Thirty-Ninth Scottish Universities Summer School in Physics, St. Andrews, June 1991. A NATO Advanced Study Institute, edited by D. P. Tunstall, W. Barford (Adam Hilger, Bristol, 1991) (1991).

5. "Elementary Excitations for Two-Dimensional Quantum Heisenberg Antiferromagnet", Guanhua Chen, Hong-Qiang Ding, William A. Goddard III*,Phys. Rev. B 46, 2933 (1992).

6. "Mechanism of Superconductivity in K3C60", Guanhua Chen, William A. Goddard III*,Proc. Nati. Acad. Sci. USA 90, 1350 (1993).

7. "Electron-Phonon Interaction and Superconductivity in K3C60", Guanhua Chen, Yuejin Guo, Naoki Karasawa, William A. Goddard III*,Phys. Rev. B 48, 13959 (1993).

8. "Resonant Tunneling through Quantum-Dot Arrays", Guanlong Chen, Gerhard Klimeck, Supriyo Datta, Guanhua Chen, William A. Goddard III*,Phys. Rev. B 50, 8035 (1994).

9. "The Valence Bond Charge Transfer Exciton Model for Predicting Nonlinear Optical Properties of Polymeric Materials", Daqi Lu, Guanhua Chen, William A. Goddard III*,J. Chem. Phys. 101, 4920 (1994).

10. "The Valence-Bond Charge Transfer Solvation Model (VB-CT-S) Nonlinear Optical Properties of Organic Molecules in Polar Solvents", Guanhua Chen, Daqi Lu, William A. Goddard III*,J. Chem. Phys. 101, 5860 (1994).

11. "The Valence-Bond Charge Transfer Model for Nonlinear Optical Properties of Charge Transfer Organic Molecules", Daqi Lu, Guanhua Chen, Joseph W. Perry, William A. Goddard III*,J. Am. Chem. Soc. 116, 10679 (1994).

12. "Electronic Coherence and Nonlinear Susceptibilities of Conjugated Polyenes", Shaul Mukamel*, Akira Takahashi, Hong Xiang Wang, Guanhua Chen,Science 266, 250 (1994).

13. "Chemical Bonding and Off-Resonance Nonlinear Polarizabilities of Conjugated Organic Molecules", Guanhua Chen, Akira Takahashi, Shaul Mukamel*,Proc. SPIE 2143, 142 (1994).

14. "Valence-Bond Charge-Transfer Theory for Predicting Nonlinear-Optical Properties of Organic Materials", William A. Goddard III*, Daqi Lu, Guanhua Chen, Joe W. Perry,ACS Symp. S. 589, 341 (1995).

15. "Hyperpolarizabilities of push-pull polyenes - molecular-orbital and valence-bond charge-transfer models", J.W. Perry, S.R. Marder, F. Meyers, D. Lu, G. Chen, W.A. Goddard III, J.L. Bredas, B.M. Pierce,ACS Symp. S. 601, 45 (1995).

16. "Nonlinear Susceptibilities of Donor-Acceptor Conjugated Systems: Coupled-Oscillator Representation", Guanhua Chen, Shaul Mukamel*,J. Am. Chem. Soc. 117, 4945 (1995).

17. "Dominant Electronic Oscillators in the Optical of Conjugated Polyenes", Guanhua Chen, Shaul Mukamel*,Chem. Phys. Lett. 240, 296 (1995).

18. "Reduced Density Matrix, Effective Hamiltonian and Nonlinear Susceptibilities of Conjugated Polymers", Guanhua Chen, Shaul Mukamel*,J. Chem. Phys. 103, 9355 (1995).

19. "The Coupled Electronic Oscillators versus the Sum-Over-States Picture for the Optical Response of Octatetraene", Guanhua Chen, Shaul Mukamel*, David Beljonne, Jean-Luc Bredas,J. Chem. Phys. 104, 5406 (1996).

20. "Effective Hamiltonian for conjugated polyenes based on the ground state single-electron density matrix", Guanhua Chen, Shaul Mukamel*,Chem. Phys. Lett. 258, 589 (1996).

21. "Nonlinear Polarizabilities of Donor-Acceptor Substituted Conjugated Polyenes", Guanhua Chen, Shaul Mukamel*,J. Phys. Chem. 100, 11080 (1996).

22. "Linear and Nonlinear Optical Response of Di-methyl-amino-nitro-stilbene (DANS) Coupled Electronic Oscillator Representation versus Sum-Over-States", David Beljonne, Jean-Luc Bredas, Guanhua Chen, Shaul Mukamel*,Chem. Phys. 210, 353-366 (1996).

23. "Multi-dimensional entropy sampling Monte Carlo method and free energy landscape of Ar13", GuanHua Chen*, Guan-Wen Wu,Chem. Phys. Lett. 281, 343-351 (1997).

24. "Effective Hamiltonians of polymethineimine, polyazine and polyazoethene: A density matrix variation approach", GuanHua Chen*, ZhongMin Su, ZhenWen Shen, YiJing Yan*,J. Chem. Phys. 109, 2565-2571 (1998).

25. "Time domain localized-density-matrix method", Satoshi Yokojima, GuanHua Chen*,Chem. Phys. Lett. 292, 379-383 (1998).

26. "Generalized Linear-Scaling Loaclized-Density-Matrix Method", WanZhen Liang, Satoshi Yokojima, GuanHua Chen*,J. Chem. Phys. 110, 1844-1855 (1999).

27. "Linear-Scaling Loaclized-Density-Matrix Method for the Ground and Excited States of One-Dimensional Molecular Systems", Satoshi Yokojima, GuanHua Chen*,Chem. Phys. Lett. 300, 540-544 (1999).

28. "Linear-scaling computation of ground state with time-domain localized-density-matrix method", Satoshi Yokojima, DongHao Zhou, GuanHua Chen*,Chem. Phys. Lett. 302, 495-498 (1999).

29. "Linear scaling calculation of excited-state properties of polyacetylene", Satoshi Yokojima, GuanHua Chen*,Phys. Rev. B 59, 7259-7262 (1999).

30. "Ground state reduced density matrices, effective Hamiltonians, and optical properties of Schiff bases of retinal", ZhongMin Su, WanZhen Liang, GuanHua Chen*,Chem. Phys. 247, 185 (1999).

31. "Localized-Density-Matrix, Segment-Molecular-Orbitals and PPV Aggregates", Satoshi Yokojima, XiuJun Wang, DongHao Zhou, GuanHua Chen*,J. Chem. Phys. 111, 10444 (1999).

32. "Optical excitations in PPV Aggregates", Satoshi Yokojima*, XiuJun Wang, GuanHua Chen*,Thin Solid Films 363, 191 (2000).

33. "Localized-Density-Matrix Method, and its Application to Carbon Nanotubes", WanZhen Liang, Satoshi Yokojima, DongHao Zhou, GuanHua Chen*,J. Phys. Chem. A 104, 2445 (2000).

34. "Localized-Density-Matrix Method and its Application to Nanomaterials", GuanHua Chen*, Satoshi Yokojima, WanZhen Liang, XiuJun Wang,Pure Appl. Chemsitry 72, 281 (2000).

35. "Localized-density-matrix method and nonlinear optical response", WanZhen Liang, Satoshi Yokojima, GuanHua Chen*,J. Chem. Phys. 113, 1403 (2000).

36. "Linear scaling computation of excited states", Satoshi Yokojima, GuanHua Chen,RIKEN Review No. 29, 77 (2000).

37. "Theoretical investigation on effects of conjugation attenuation of poly(p-phenylenevinylene) incorpotating 2,2-bipyridines", Man-Fai Ng, Satoshi Yokojima, DongHao Zhou, GuanHua Chen*,Chem. Phys. Lett. 327, 374 (2000).

38. "Reduced density matrix and combined dynamics of electrons and nuclei", Yang Zhao, Satoshi Yokojima, GuanHua Chen*,J. Chem. Phys. 113, 4016 (2000).

39. "Lattice and spin polarons in two dimensions", Yang Zhao, GuanHua Chen*, L. Yu,J. Chem. Phys. 113, 6502 (2000).

40. "Electronic Structures and Optical Properties of Open and Capped Carbon Nanotubes", WanZhen Liang, XiuJun Wang, Satoshi Yokojima, GuanHua Chen*,J. Am. Chem. Soc. 122, 11129 (2000).

41. "Localized-Density-Matrix Method, and its Application to Carbon Nanotubes", Satoshi Yokojima, WanZhen Liang, XiuJun Wang, Man Fai Ng, DongHao Zhou, GuanHua Chen*,Physics and Chemistry of Nanostructured Materials, edited S. Yang and P. Sheng (Taylor & Francis, London and New York, 2000) (2000).

42. "Photoexcitations in Poly(p-phenylenevinylene) Aggregates", Satoshi Yokojima, DongHao Zhou, GuanHua Chen*,Chem. Phys. Lett. 333, 397 (2001).

43. "Quantum dissipative master equations: Some exact results", Yang Zhao, GuanHua Chen*,J. Chem. Phys. 114, 10623 (2001).

44. "Optical Properties of Single-Walled 4 A Carbon Nanotubes", W.Z. Liang, S. Yokojima, M.F. Ng, G.H. Chen*, G. He,J. Am. Chem. Soc. 123, 9830 (2001).

45. "Optical response of small diameter single-walled carbon nanotubes", Satoshi Yokojima*, WanZhen Liang, GuanHua Chen*,Mechanics and Material Engineering for Science and Experiments, edited by Yichun Zhou, Yuanxian Gu and Zheng Li (Science Press, New York, 2001) (2001).

46. "Excitation and dissipation of interacting many-electron system", S. Yokojima, G.H. Chen*,Chem. Phys. Lett. 355, 400 (2002).

47. "Density Matrix Negativity for Two Oscillators in an Agarwal Bath", Y. Zhao, G.H. Chen*,Phys. Rev. E 65, 56120 (2002).

48. "Absorption Spectra and Chirality of Single-Walled 4 A Carbon Nanotubes", W.Z. Liang, G.H. Chen*, Z. Li, Z.-K. Tang,Appl. Phys. Lett. 80, 3415 (2002).

49. "Pathway analysis on electron transfer in ruthenium modified cytochrome c", G.H. Chen*, C.K. Tsang, G.S.M. Tong,J. Theo. Comp. Chem. 1, 93 (2002).

50. "Localized-Density-Matrix Method: a Linear-Scaling Quantum Chemistry Method for Ground and Excited States", XiuJun Wang, GuanHua Chen*,Frontiers of Theoretical Physics and Its Related Fields-Annual Academic Exchange in 2002, ed. Naiyan Wang, page 121-137 (2002).

51. "Localized-density-matrix method: a linear scaling quantum chemistry method for ground and excited states", GuanHua Chen*, Satoshi Yokojima, Chi Yung Yam,Modern Topics in Chemical Physics, page 49-85, edited Thomas F. George, Xin Sun and Guoping Zhang (Research Signpost, Kerala, India, 2002) (2002).

52. "Two oscillators in a dissipative bath", Y. Zhao, G.H. Chen*,Physica A 317, 13 (2003).

53. "A dynamic mean field theory for dissipative interactive many-electron systems", S. Yokojima, G.H. Chen*, R. Xu, Y.J. Yan*,Chem. Phys. Lett. 369, 495 (2003).

54. "Localized-density-matrix calculations of circular dichroism spectra of optically active molecular systems", WanZhen Liang, Satoshi Yokojima, GuanHua Chen*,Chem. Phys. 289, 175 (2003).

55. "Low-lying excited states of light harvesting system II in purple bacteria", Man-Fai Ng, Yang Zhao, GuanHua Chen*,J. Phys. Chem. B 107, 9589 (2003).

56. "A dynamic mean field theory for dissipative interacting many-electron systems. Markovian formalism and its implementation", S. Yokojima, G.H. Chen*, R. Xu, Y.J. Yan*,J. Comp. Chem. 24, 2083 (2003).

57. "Energy dissipation mechanisms in carbon nanotube oscillators", Y. Zhao, C.C. Ma, G.H. Chen*, Q. Jiang,Phys. Rev. Lett. 91, 175504 (2003).

58. "Localized-density-matrix implementation of time-dependent density-functional theory", C.Y. Yam, S. Yokojima, G.H. Chen*,J. Chem. Phys. 119, 8794 (2003).

59. "Linear-scaling time-dependent density functional theory", ChiYung Yam, Satoshi Yokojima, GuanHua Chen*,Phys. Rev. B 68, 153105 (2003).

60. "Combined first-principles calculation and neural-network correction approach for heat of formation", L.H. Hu, X.J. Wang, L.H. Wong, G.H. Chen*,J. Chem. Phys. (Commun.) 119, 11501 (2003).

61. "A combined first-principles calculation and Neural Networks correction approach for evaluating Gibbs energy of formation", X.J. Wang, L.H. Hu, L.H. Wong, G.H. Chen*,Molecular Simulation 30, 9 (2004).

62. "Quantum mechanical investigation of field emission mechanism of a micrometer-long single-walled carbon nanotube", X. Zheng, G.H. Chen*, Z.B. Li, S.Z. Deng, N.S. Xu,Phys. Rev. Lett. 92, 106803 (2004).

63. "Low-lying excited states of light-harvesting system II in purple bacteria", Yang Zhao, ManFai Ng, GuanHua Chen*,Phys. Rev. E 69, 032902 (2004).

64. "Absorption-Spectral Features of Single-Walled Carbon Nanotubes", Y. Zhao, X.J. Wang, C.-C. Ma, G.H. Chen*,Chem. Phys. Lett. 387, 149 (2004).

65. "A generalized exchange-correlation functional: the Neural Networks approach", X. Zheng, L.H. Hu, X.J. Wang, G.H. Chen*,Chem. Phys. Lett. 390, 186 (2004).

66. "Stacking behavior of 2-D assemblies of octa-alkoxyl-substituted phthalocyanine studied by scanning tunneling microscopy", Y.-H. Liu, S.-X. Yin, C.-C. Ma, G.H. Chen*, C. Wang, L.-J. Wan, C.-L. Bai,Surf. Sci. 559, 40 (2004).

67. "Improving the accuracy of density functional theory calculation: the statistical correction approach", XiuJun Wang, LaiHo Wong, LiHong Hu, ChakYu Chan, Zhongmin Su, GuanHua Chen*,J. Phys. Chem. A 108, 8514 (2004).

68. "Identification of novel small molecule inhibitors of severe acute respiratory syndrome associated coronavirus by chemical genetics", Richard Y. Kao, Wayne H.W. Tsui, Terri S. W. Lee, Julian A. Tanner, Rory M. Watt, Jian-Dong Huang, Lihong Hu, Guanhua Chen*, Zhiwei Chen, Linqi Zhang, Tien He, Kwok-Hung Chan, Herman Tse, Amanda P. C. To, Louisa W. Y. Ng, Bonnie C. W. Wong, Hoi-Wah Tsoi, Dan Yang, David D. Ho, Kwok-Yung Yuen,Chemistry & Biology 11, 1293 (2004).

69. "Electronic Structure and Charge Distribution of Potassium-Iodide-Intercalated Single-Walled Carbon Nanotubes", C.Y. Yam, C.-C. Ma, X.J. Wang, G.H. Chen*,Appl. Phys. Lett. 85, 4484 (2004).

70. "Accurate prediction of heat of formation by combining Hartree-Fock/density functional theory calculation with linear regression correction approach", X.-M. Duan, G.-L. Song, Z.-H. Li, X.J. Wang, G.H. Chen*, K.-N. Fan,J. Chem. Phys. 121, 7086 (2004).

71. "Why Does Disubstituted Hexamolybdate with Arylimido Prefer to Form an Orthogonal Derivative? Analysis of Stability, Bonding Character, and Electronic Properties on Molybdate Derivatives by Density Functional Theory (DFT) Study", L.-K. Yan, Z.-M. Su, W. Guan, M. Zhang, G.H. Chen*, L. Xu, E.-B. Wang,J. Phys. Chem. B 108, 17337 (2004).

72. "Quantum entanglement and the self-trapping transition in polaronic systems", Y. Zhao, O. Zanardi, G.H. Chen*,Phys. Rev. B 70, 195113 (2004).

73. "New Mechanism of Carbon Nanotube Field Emission", Z.B. Li, N.S. Xu, S.Z. Deng, X. Zheng, G.H. Chen*,Physics (Commun.) 33, 705 (2004).

74. "Bending Instability Characteristics of Double-Walled Carbon Nanotubes", Q. Wang, T. Hu, G.H. Chen*, Q. Jiang,Phys. Rev. B, 71, 045403 (2005).

75. "Structure, Assembly and Topology of the G185R Mutant of the Fourth Transmembrane Domain of Divalent Metal Transporter", Fei Li, Hongyan Li, LiHong Hu, Miufan Kwan, GuanHua Chen*, Qing-Yu He, Hongzhe Sun,J. Am. Chem. Soc., 127, 1414 (2005).

76. "Linear-scaling quantum mechanical methods for nanoscopic structures", C.Y. Yam, X. Zheng, G.H. Chen*,Handbook of Theoretical and Computational Nanotechnology, edited Michael Reith and Wolfram Schommers (American Scientific Publishers, California, 2005) (2005).

77. "Theoretical investigation of optical properties of single-walled carbon nanotubes", Y. Zhao, X.J. Wang, C.C. Ma, G.H. Chen*,Handbook of Theoretical and Computational Nanotechnology, edited Michael Reith and Wolfram Schommers (American Scientific Publishers, California, 2005) (2005).

78. "Neural network correction for heats of formation with a larger experimental training set and new descriptors", Xue-Mei Duan, Zhen-Hui Li, Guo-Liang Song, Wen-Ning Wang, Guan-Hua Chen*, Kang-Nian Fan,Chem. Phys. Lett. 410, 125 (2005).

79. "Quantum mechanical understanding of field dependence of the apex barrier of a single-wall carbon nanotube", J. Peng, Z.B. Li, C.S. He, S.Z. Deng, N.S. Xu, X. Zheng, G.H. Chen*,Phys. Rev. B 72, 235106 (2005).

80. "Linear regression correction to fist principle theoretical calculations - Improved descriptors and enlarged training set", Xue-Mei Duan, Zhen-Hua Li, Hai-Rong Hu, Guo-Liang Song, Wen-Ning Wang, GuanHua Chen*, Kang-Nian Fan,Chem. Phys. Lett. 409, 315 (2005).

81. "Theoretical interpretation of different nanotube morphologies among Group III (B, Al, Ga) nitrides", Min Zhang, Zhong-Min Su, Li-Kai Yan, Yong-Qing Qu, GuanHua Chen*, Rong-Shun Wang,Chem. Phys. Lett. 408, 145 (2005).

82. "A tribological study of double-walled and triple-walled carbon nanotube oscillators", Chi-Chiu Ma, Yang Zhao, Chi-Yung Yam, GuanHua Chen*, Qing Jiang,Nanotechnology 16, 1253 (2005).

83. "First-Principles Method for Open Electronic Systems", Xiao Zheng, GuanHua Chen*,arXiv:physics (2005).

84. "Quasi-Reversible Energy Flows in Carbon-Nanotube-Based Oscillation", Y. Zhao, C.-C. Ma, L.-H. Wong, G.H. Chen*, Z.P. Xu, Q.S. Zheng, Q. Jiang, A.T. Chwang,J. Comp. Theo. Nanosci. 3, 852 (2006).

85. "Some progresses in density-functional theory: efficiency, accuracy and applicability", Chi-Yung Yam, Xiao Zheng, GuanHua Chen*,J. Comp. Theo. Nanosci. 3, 857 (2006).

86. "Green Luminescence Band in ZnO: Fine Structures, Electron-Phone Coupling, and Temperature Effects", S.L. Shi, G.Q. Li, S.J. Xu, Y. Zhao, G.H. Chen*,J. Phys. Chem. B 110, 10475 (2006).

87. "Effect of temperature on field emission from a micrometer-long single-walled carbon nanotube", C.-S. Wan, Z.-H. Li, K.-N. Fan, X. Zheng, G.H. Chen*,Phys. Rev. B. 73, 165422 (2006).

88. "Grooving the carbon nanotube oscillators", Y. Zhao, L.H. Wong, G.H. Chen*, A.T. Chwang,Appl. Phys. Lett. 88, 183107 (2006).

89. "Quantum dissipation and broadening mechanisms due to electron-phonon interactions in self-formed InGaN quantum dots", S.J. Xu, G.Q. Li, Y.J. Wang, Y. Zhao, G.H. Chen*, D.G. Zhao, J.J. Zhu, H. Yang, D.P. Yu, J.N. Wang,Appl. Phys. Lett. 88, 083123 (2006).

90. "Energy exchanges in carbon nanotube oscillators", Yang Zhao, Chiu-Chiu Ma, Lai-Ho Wong, GuanHua Chen*, ZhiPing Xu, QuanShui Zheng, Qing Jiang, Allen T. Chwang,Nanotechnology 17, 1032 (2006).

91. "A neural networks-based drug discovery approach and its application for designing aldose reductase inhibitors", LiHong Hu, GuanHua Chen*, Raymond Ming-Wah Chau,J. Mol. Graph. Mod. 24, 244 (2006).

92. "Theoretical absorption spectra of silicon carbide nanocrystals", S.L. Shi, S.J. Xu, X.J. Wang, G.H. Chen*,Thin Solid Films 495, 404 (2006).

93. "Trans-phonon effects in ultrafast nano-devices", Zhiping Xu, Quanshui Zheng, Chi-Chiu Ma, Yang Zhao, GuanHua Chen*, Qing Jiang, Huajian Gao,Full text, in press (2006).

94. "Existence of A Density-Functional Theory for Open Electronic Systems", GuanHua Chen*,Lecture Series on Computer and Computational Sciences, 7, 803 (2006).

95. "The Oscillatory Characteristics of a 2C60/CNT Oscillator System", X. Wang, H. Xin, J. N. Leonard, G.H. Chen*, A. T. Chwang, Q. Jiang,J. Nanoscience and Nanotechnology 7, 1512 (2007).

96. "Atomic Decoration for Improving the Efficiency of Field Emission of Carbon Nanotubes", G. Chen, Z. Li, J. Peng, C. He, W. Wang, S. Deng, N. Xu, C. Wang, S. Wang, X. Zheng, G.H. Chen*, T. Yu,J. Phys. Chem. C 111, 4939 (2007).

97. "Structure-activity relationships of flavonoids for vascular relaxation in porcine coronary artery", Y.C. Xu, S.W.S. Leung, D.K.Y. Yeung, L.H. Hu, G.H. Chen*, C.M. Che, R.Y.K. Man,Phytochemistry 68, 1179 (2007).

98. "Maxwell's demon and Smoluchowski's trap door", J. Zheng, X. Zheng, Y. Zhao, Y. Xie, C.Y. Yam, G.H. Chen*, Q. Jiang, A.T. Chwang,Phys. Rev. E 75, 041109 (2007).

99. "Density matrix based time-dependent density functional theory and the solution of its linear response in real time domain", F. Wang, C.Y. Yam, G.H. Chen*,J. Chem. Phys. 126, 134104 (2007).

100. "Time-dependent density-functional theory for open systems", X. Zheng, F. Wang, C.Y. Yam, Y. Mo, G.H. Chen*,Phys. Rev. B 75, 195127 (2007).

101. "Thermally driven Large-amplitude fluctuations in carbon-nanotube-based devises: Molecular dynamics simulations", Z. Xu, Q.S. Zheng, G.H. Chen*,Phys. Rev. B 75 195445 (2007).

102. "Improving the accuracy of density-function theory calculation: The genetic algorithm and neural network approach", H. Li, L.L. Shi, M. Zhang, Z. Su, X.J. Wang, L.H. Hu, G.H. Chen*,J. Chem. Phys. 126, 144101 (2007).

103. "Elementary building blocks of graphene-nanoribbon-based electronic devices", Z.P. Xu, Q.S. Zheng, G.H. Chen*,Appl. Phys. Lett. 90, 223115 (2007).

1. "Computer simulation of Feynman's ratchet and pawl system", Jianzhou Zheng, Xiao Zheng, GuanHua Chen

2. "Bacteria transport in asymmetric channels", Jianzhou Zheng, GuanHua Chen