个人简历

1991年获博士学位，1996年晋升教授，1998年至今任职于浙江大学数学科学学院，作为博士生导师，2000年至今已培养出22位博士生，有的已成为国内有一定学术影响的青年学者。至今共发表论文134篇，其中绝大部分在SCI刊物上，包括一些国际上有重要影响的Top期刊。研究涉及代数和表示论领域的多个方面，在丛代数、Hopf代数和量子群、代数表示论和代数的拓扑方法上取得了代表性成果。
已先后主持国家自然科学基金六项和浙江省自然科学基金重大和重点项目各一项。曾获浙江省高校科技进步一等奖等奖项，是国家教育部新世纪人才和浙江省151人才入选者。
在教学与人才培养方面，改革培养模式与课程内容,是《高等代数》课程建设的负责人，是浙江大学研究生核心课程建设项目《现代数学概论》负责人，2010年至今，为浙江大学求是科学班（拔尖人才培养）主讲老师。
每年应邀在国内外各学术会议上做邀请报告,比如：第十三届全国代数学学术会议大会报告，2013年8月，长春；第七届全球华人数学家大会做45分钟邀请报告，2016年8月，北京；中国数学会2017年学术年会代数与数论分组邀请报告，2017年10月，湘潭；等等。
现为浙江大学高等数学研究所所长、代数基层教学组织责任教授；

研究领域

代数与表示论""

近期论文

1 Li,Fang:On the spectra of P-and P0-matrices.Lin.Alg.Appl.119:1-25(1989)
2 Li,Fang:The uniqueness of Lyapunov scaling factors of matrices.J.Lanzhou Univ.(Chinese)27(3):9-17(1991)
3 Li,Fang:The weak regularity of semigroup rings.Northeastern Math.J.8(6):1-3(1992)
4 Li,Fang:Semigroup algebras over fields of Characteristic 0.J.Northwest Normal Univ.(Chinese)28(3):24-27(1992)
5 Li,Fang:Von Neumann's regularity of semigroup rings.Nature J.(Chinese)15(5):391(1992)
6 Li,Fang:Semisimplicity of semigroup rings.J.Lanzhou Univ.(Chinese)29(2):9-13(1993)
7 Li,Fang:The existence of identity of orthodox semigroup rings.Semigroup Forum 46:27-31(1993)
8 Li,Fang:Elementary operations and Laplaces theorem on quantum matrices.J.Physics(A:Math.&Gen.)26(17):4287-4297(1993)
9 Li,Fang:Existence of identity of semigroup rings.J.Math.Research&Exposition(Chinese)13(2):292(1993)
10 Li,Fang:A study on alomst cocommutative bialgebras.Proceedings of the First China Post-doctoral Academic Congress 1325-1328(1993)
11 Li,Fang:Some studies on semigroups and semigroup rings(Abstract).Adv.Math.(China)22(5):478-479(1993)
12 Li,Fang:The self-injectivity of rings and semigroup rings.Annals of Math.Researches(Chinese)26(2):58-64(1993)
13 Li,Fang:A new proof of the structure of generalized Brandt semigroups.Pure and Applied Math.(Chinese)9(2):53-56(1993)
14 Li,Fang:On the weak regularity of semigroup rings.Semigroup Forum 48(2):152-162(1994)
15 Li,Fang:Weak regularity of rings.J.Math.Research&Exposition(Chinese)14(4):607-611(1994)
16 Li,Fang:Relations among associative algebras,semigroup algebras and bialgebras.J.Southeast Univ.(English Series)10(2):13-17(1994)
17 Li,Fang:0-direct union decomposition of primitive regular semigroups.J.Lanzhou Univ.(Chinese)30(2):15-17(1994)
18 Li,Fang:The regularity of Munn rings and semigroup rings.Acta Math.Sinica(New Series)11(1):53-61(1995)
19 Li,Fang:On almost cocommutaitve bialgebras.J.Nanjing Univ.(Mathematics Biquarterly 12(2):179-190(1995)
20 Li,Fang:LU-decompositon of P0-matrices.J.Southeast Univ.(Chinese)25(3):115-119(1995)
21 Li,Fang:Regularity of semigroup rings.Semigroup Forum 53:72-81(1996)
22 Li,Fang:Left free normalized extensions and quasi-excellent extensions of rings.Acta Math.Sinica(Chinese)40(5):653-658(1997)
23 Li,Fang:Generalization of normalizing extensions and some applications.Comm.Algebra 25(3):873-885(1997)
24 Li,Fang and Zhang,Liang-Yun:Weak Hopf algebras and rings of fractions of semigroup rings.J.Nanjing Univ.(Math.Biquarterly)(Chinese)
14(1):98-104(1997)
25 Zhang,Liangyun and Li,Fang:Properties of smash product and double smash product.J.Southeast Univ.(Chinese)28(4):102-106(1998)
26 Li,Fang and Liu,Haisheng:Some results on Hadamard matrices.J.Southeast Univ.(Chinese)28(5):143-147(1998)
27 Li,Fang:Weak Hopf algebras and some new solutions of quantum Yang-Baxter equation.J.Algebra 208:72-100(1998)
28 Liu,Zhongkui and Li,Fang:PS-rings of generalized power series.Comm.Algebra 26(7):2283-2291(1998)
29 Liu,Zhongkui and Li,Fang:Completely A-absolutely orthodox semigroups.J.Math.(Chinese)18(2):191-195(1998)
30 Li,Fang and Tian,Rong-xiang:q-Paul matrices and a representation of quantum Heisenberg algebras.J.Hangzhou Univ.(Chinese)26(1):7-
10(1999)
31 Li,Fang:Weak Hopf algebras and regular monoids.J.Math.Research&Exposition 19(2):325-331(1999)
32 Li,Fang:Solutions of Yang-Baxter equation in endomorphism semigroups and quasi-(co)braided almost bialgebras.Comm.Algebra,
28(5):2253-2270(2000)
33 Li,Fang and Liu,Zhongkui:A sufficient condition for smash product as a transfinite left free normalizing extension and its application.Acta
Math.Sinica(Chinese Series)42(2):377-381(1999);(English Series)16(1):71-78(2000)
34 Li,Fang:Green's equivalences on coalgebras.Acta Math.Sinica(Chinese),43(3):399-414(2000)
35 Liu,Zhongkui and Li,Fang:On locally Noetherian modules.J.of Math.Research&Exposition 20(4):491-497(2000)
36 Li,Fang:Weaker structures of Hopf algebras and singular solutions of Yang-Baxter equation,Symposium on The Frontiers of Physics at
Millennium,143-147,World Scientific Publishing Co.Pte.Ltd,Singapore,2001
37 Duplij,Steven and Li,Fang:On regular solutions of Quantum Yang-Baxter equation and weak Hopf algebras.Journal of Kharkov National
University,ser.Nuclei,Particles and Fields 521,15-30(2001)
38 Li,Fang and Tong,Xiao-ping:Amendment and imporovement of some basic conclusions in'Hopf Algebra'(E.Abe),Journal of Zhejiang
University(Science Edition),28(5):473-477(2001)
39 Duplij,Steven and Li,Fang:Regular Solutions of Quantum Yang-Baxter Equation from Weak Hopf algebras,Czechoslovak J.of Physics,51(12):1306-1311(2001)
40 Li,Fang:Some weaker structures of Hopf algebras,J.of Zhejiang University(Science),29(3):246-254(2002)
41 Li,Fang and Duplij,Steven:Weak Hopf algebras and singular solutions of Quantum Yang-Baxter equation,Comm.Math.Phys.225:191-
217(2002)
42 Li,Fang:The right braids,quasi-braided pre-tensor categories and general Yang-Baxter operators,Comm.Algebra,32(2):397-441(2004)
43 Wang,Guojun,Li,Fang,Liu,Gngxiang:Advance of Researches on Weaker Structures of Hopf Algebras,Chinese Academic Forum,Vol.10:
28-33(2004)
44 Li,Fang and Trotter,P G:Concise Encyclopaedia of Supersymmetry and Noncom-mutative Structures in Mathematics and Physics,editted
by S.Duplij,W.Siegel,J.Bagger,Kluwer Academic Publishers,Dordrecht,2004,ISBN 1-4020-1338-8,pp.92-93,97,209,502-503
45 Li,Fang:On quasi-bicrossed products of weak Hopf algebras,Acta Math.Sinica(English Series),20(2):305-318(2004)
46 Li,Fang and Zhang,Yao-zhong:Quantum Doubles From A Class of Noncocom-mutative Weak Hopf Algebras,J.of Math.Physics 45(8):
3266-3281(2004)
47 Li,Fang:Structure theorem of a right Hopf module over a right Hopf algebra,Algebra Colloquium 11(3):301-312(2004)
48 Li,Fang:structure of quantum doubles of finite Clifford monoids,Comm.in Algebra 32(10):4085-4097(2004)
49 Li,Fang and Chen,Lili:Set-Representation Of A Quiver And Relationship With Linear-Representation,Scientiae Mathematicae Japonicae 62(1):47-56(2005);Online:139-148(e-2005)
50 Jia,Ling and Li,Fang:Rudiment of weak Doi-Hopf pi-modules,J.Zhejiang Univ.(SCI)6A(Suppl.I)(2005),144-154
51 Li,Fang and Cao,Haijun:Semilattice graded weak Hopf algebra and its related quantum G-double,Journal of Mathematical Physics 46(8):083519-1~17(2005)
52 Li,Fang and Cao,Haijun:Semilattice graded weak Hopf algebra and its quantum doubles,ADVANCES IN RING THEORY,Proceedings of the 4th China-Japan-Korea International Conference Nanjing,China 24-28 June 2004,pp.139-150 edited by J L Chen(Southeast University,China),N Q Ding(Nanjing University,China)&H Marubayashi(Naruto University of Education,Japan),
World Scientific,Pub.date:Aug 2005,ISBN 981-256-425-X
53 Liu,Gongxiang and Li,Fang:On strongly groupoid graded rings and the corresponding Clifford theorem',Algebra Colloquium 13(2):181-196(2006)
54 Shi,Meihua and Li,Fang:The categroy of modules over a triangular matrix ring of order n and its homological characterizations,Acta Math.Sinica(Chinese Series),49(1):215-224(2006)
55 Li,Fang and Liu,Gongxiang:Weak tensor category and related generalized Hopf algebras,Acta Mathematica Sinica(English Series),22(4):1027-1046(2006)
56 Zhang,Liangyun and Li,Fang:Cylinder Coalgebras and Cylinder Coproducts for Quasitriangular Hopf Algebras,数学研究与评论，26(4):635-648(2006)
57 Jia,Ling and Li,Fang:Global dimension of weak smash product,J.of Zhejiang University(Science A)2006,12(7),2088-2092
58 Li,Fang and Zhang Mianmian:Invariant properties of representations under cleft extensions,Science in China(Series A-Mathematics),2006,36(12),1377-1388(in Chinese);2007,Vol.50,No.1,pp.121-131(in English)
59 Liu,Gongxiang and Li,Fang:Pointed Hopf algebras of finite representation type and their Classification,Proc.AMS,135(2007),649-657
60贾玲和李方:弱entwined模的Frobenius性质和Maschke型定理，数学学报（中文版），50(1):105-116(2007)
61 Ye,Lixia and Li,Fang:Weak quantum Borcherds superalgebras and their representations,Journal of Mathematical Physics,2007,48(2):023502,pp.16
62 Jia,Ling and Li,Fang:On weak group entwined structure,Houston Journal of Mathematics,33(2):433-450(2007)
63 Jia Ling and Li Fang:The cohomology group of weak entwining structure，Science in China(Series A-Mathematics),37(1):55-63(2007)
64 Qiao,Husheng,Li,Fang:When all S-Posets Are Principally Weakly Flat,Semigroup Forum,75(2007),536–542
65 Li,Fang:Characterization of left Artinian algebras through pseudo path algebras,J.of Austr.Math.Soc.83(2007):385-416.
66 Qiao,Husheng,Li,Fang:The flatness properties of S-poset A(I)and Rees factor S-posets,Semigroup Forum,77(2008),306–315
67 Jia Ling and Li Fang:弱Hopf代数上的几乎可裂序列，数学学报（中文），2008年7月，51（4）,749-754
68Jia,Ling;Li,FangAlternative Doi-Hopf modules over weak Hopf algebras.(Chinese)Acta Math.Sci.Ser.A Chin.Ed.28 (2008), no.6,1067--1076
69 Li,Fang,Cao,Haijun and Wang Guojun:A special class of tensor categories initiated by inverse braid monoids,Discrete Mathematics 308(2008)4978-4991
70 Li,Fang and Wen,Daowei:Ordinary quiver,AR-quiver and natural quiver of an algebra,in Geometry,Analysis and Topology of Discrete Groups,271—304,Advanced Lectures in Mathematics 6,Editors:Lizhen Ji,Kefeng Liu,Lo Yang,Shing-Tung Yau,Higher Education Press&International Press,Beijing,2008
71 Munir Ahmed and Fang Li:The Representation of Clifford Monoids and Semilattice Graded Weak Hopf Algebras:A Motivating Note,Journal of Modern Mathematics and Statistics 2(3):85-92,2008
72 Wang,Guojun and Li,Fang:On minimal Horse-shoe Lemma,Taiwanese J.of Mathematics,12 (2008), no.2,373--387.
73 Li,Fang and Liu,Gongxiang:Generalized Path Coalgebra And Generalized Dual Gabriel Theorem,Acta Math.Sinica(Chinese Series),51(5),2008,853-862
74 Munir Ahmed,Fang Li：Self-Dual Weak Hopf Algebras，Acta Math.Sinica(Series B)，Dec.,2008,Vol.24,No.12,pp.1935–1948
75 Munir Ahmed and Fang Li:Ore extensions as weak Hopf algebras,The Arabian Journal for Science and Engineering,33(2C),2008,19-26(SCI)
76 Mianmian Zhang and Fang Li,Representations of skew group algebras induced
from ii-modules of path algebras,Journal of Algebra 321(2009)567–581
77 Dongming Cheng and Fang Li,THE STRUCTURE OF WEAK HOPF ALGEBRAS CORRESPONDING TO Uq(sl2),Communications in Algebra,37(2009):729–742
78 Chen,Lili and Li,Fang:Dual Hopf algebras from a quiver and dual quiver quantum groups（由箭图构造的对偶Hopf代数和量子群）,数学物理学报Acta Mathematica Scientia，2009,29A(2)：505-516
79Jia,Ling;Li,FangDoi-Hopf$pi$-modules and Yetter-Drinfeld$pi$-modules over a weak$T$-coalgebra.Adv.Math.(China)38 (2009), no.1,117—126
80Qiao,Husheng;Li,FangOn monoids for which all condition$(P)$acts are strongly flat.Comm.Algebra37 (2009), no.1,234—241
81 Ye,Li-xia;Li,Fang,Center and quasi-R-matrix of weak quantum Borcherds superalgebras,Advances in Mathematics(China),38(2009),no.5,566-578
82.Li,Fang,Chen,Lili:The natural quiver of an artinian algebra,Algebras and representation theory,Published online,28 November 2009；Volume 13,Issue 5(2010),Page 623--636.
83 Jia,Ling and Li,Fang:Quantum Double for a Weak T–Coalgebra,Algebra Colloquium,17:3(2010)475--486
84 Wang,Guojun and Li,Fang:The generalized extension closure of Koszul objects,ACTA MATHEMATICA SINICA,Chinese Series,53(6)（2010）:1065-1074
85 A.Munir,F.Li:WEAK HOPF QUIVERS,CLIFFORD MONOIDS AND WEAK HOPF ALGEBRAS,The Arabian Journal for Science and Engineering，(2011)36:375–392(SCI)
86 Haiyan Zhu and Fang Li,Weakly Ordered Multiplicative Basis of An Algebra Related to Quiver Theory,Journal of Algebra 348(2011)196-216
87.Fang Li and Qinxiu Sun,A survey on weak Hopf algebras,Quantized Algebras and Physics,Nankai Series in Pure & Applied Mathematics and Theoretical Physics-Vol.8,pp.166-186,edited by M.L.Ge,C.M.Bai,N.H.Jing,World Scientific,Oct.2011
88.Li,Fang and Chen,Lili:Hopf algebra structure over generalized path coalgebras,Pure and Applied Mathematics Quarterly,8(3),693-711(2012)
89Fang Li and Zongzhu Lin:Approach to artinian algebras via natural quivers,Transactions of The American Mathematical Society,364(3),2012:1395–1411;Article electronically published on November 7,2011
90.Fang Li：Modulation and natural valued quiver of an algebra，Pacific Journal of Mathematics，256(1):105-128(2012).
91.Yanyong Hong,Fang Li:'Weak Hopf algebras corresponding to quantum algebras$U_q(f(K,H))$',Arabian Journal of Mathematics(2012)1:195–218
92.Fang Li and Longgang Sun:Invariants under stable equivalences of Morita type,,Acta Mathematica Scientia 2012,32B(2):605–618
93 Chen,Lili and Li,Fang:On the structure and representations of non-balanced quantum doubles,Appl.Math.J.Chinese Univ.2012,27(4):475-488
94 Fang Li,Longgang Sun,Derived Representation type and Gorenstein-projective modules of an algebra under crossed product，SCIENCE CHINA Mathematics(Math.English Series)，56(3):531-540(2013)
95 Xiuli Chen,Haiyan Zhu and Fang Li,Cotorsion dimensions and Hopf algebra
actions,Mathematical Notes,2013,Vol.93,No.4,pp.616–623
96.Chen,Xiuli,Zhu,Haiyan,Li,Fang,Invariants of FP-projective dimensions under cleft extensions,Algebra Colloquium 20:4(2013),689—700
97.LI Fang and LIU Jichun：Wedderburn principal theorem of a complete algebra in I-adic topology,Advances in Mathematics(China)42(4):501-504(2013)
98.Xingyu Dai,Fang LI,Kefeng Liu,Boltje-Maisch resolutions of Specht modules,
Pure and Applied Mathematics Quarterly,9(3):437--459(2013)
99．Haijun Cao,Fang Li,Mianmian Zhang,Constructing pointed weak Hopf
algebras by Ore-extension,Acta Mathematica Scientia,Volume 34,Issue 2,Pages
252–262(March 2014)
100.Fang Li,Jichun Liu,Yichao Yang:Genuses of cluster quivers of finite mutation type,Pacific Journal of Mathematics,269(1):133-148(2014)
101.Li Guo and Fang Li,Structure of Hochschild cohomology of path algebras and differential formulation of Euler’s polyhedron formula，Asian Journal of Math.，Vol.18,No.3,pp.545–572,July 2014;arXiv:1010.1980v2[math.RA]
102 Fang Li and Dezhan Tan，Graded Hochschild cohomology of a path algebra with oriented cycles，Acta Mathematica Sinica,English Series,Sep.,2014,Vol.30,No.9,pp.1495–1512
103.Xingyu Dai,Fang LI,Kefeng Liu,Bases of q-Schur Module A^{lambda},Pure and Applied Mathematics Quarterly，10(3),439-458(2014)
104.Fang Li,Jichun Liu,Yichao Yang:Non-planar cluster quivers from surface，
Annals of Combinatorics,18(2014)675–707,DOI 10.1007/s00026-014-0247-4,
Published online November 13,2014
105.Fang Li and Yichao Yang,'A note on section and slice for a hereditary algebra',
International Journal of Applied Mathematics and Statistics,52(9):112-119(2014).
106.李志兰，李方,量子Yang-Baxter方程的集合解的进展,科技通报，Vol.31,No.1,Jan.2015,1-3;
107.Yanyong Hong,Fang Li:On Left-Symmetric Conformal Bialgebras,Journal of Algebra and Its Applications,Vol.14,No.1(2015)1450079(37 pages)
108Steven Duplij,Yanyong Hong,Fang Li:Uq(sl(m+1))-Module Algebra Structures on the Coordinate Algebra of Quantum Vector Space,Journal of Lie Theory,Volume 25(2015)327-361
109.Fang Li,Chang Ye,Gorenstein projective modules over a class of generalized matrix algebras and their applications,Algebras and Representation Theory,(2015)18:693–710
110.Fang Li and Yichao Yang,A relation between tilting graphs and cluster-tilting graphs of hereditary algebras,Frontiers of Mathematics in China,2015,10(2):275–291
111.Fang Li,Dezhan Tan:On the first Hochschild cohomology of admissible algebras,Chinese Annals of Mathematics,(Series B),36B(6),1027--1042,2015
112 Fang Li and Dezhan Tan,Differential Grading Structures on a Path Category',Algebra Colloquium,22(4):(2015)677—686
113.Yanyong Hong,Fang Li,Left-symmetric conformal algebras and vertex algebras,Journal of Pure and Applied Algebra 219(2015)3543–3567
114.Min Huang,Fang Li,On structure of cluster algebras of geometric type,II:Green equivalences and paunched surfaces,Pure and Applied Mathematics Quarterly Volume 11,Number 3,451–490,2015(出版日期2016年11月)
115.Yong Wang,Fang Li,Gorenstein Global Dimension and Hopf algebroid Actions,Journal of Algebra and Its Applications,Vol.15,No.5(2016)1650090(31 pages)
116.Feifei Duan,Fang Li,CARTAN INVARIANTS FOR THE WITT SUPERALGEBRA W(2)in positive characteristic,Journal of Algebra and Its Applications,Vol.15,No.3(2016),1650039(24 pages).
117.Fang Li,Lingyu Wan,On duality preservability of Auslander-Reiten quivers of derived categories and cluster categories,Frontiers of Mathematics in China,2016,11(4):957–984
118.Munir Ahmed and Fang Li:Basic Weak Hopf Algebras and Weak Covering Quivers,Journal of Zhejiang University(Science Edition),2016,43(4):379-388,410.
119.Fang Li,Lingyu Wan,On P-derivations and P-Jordan derivations of a ring,Italian J.of Pure and Applied Mathematics 36(2016):639-650.(EI)
120.Fang Li,Chang Ye,Representations of Frobenius-type triangular matrix algebras,Acta Mathematica Sinica,English Series,2017,V.33,N.3,pp 341–361
121.Haiyan Zhu and Fang Li,Quiver approach to some ordered semigroup algebras,Communications in Algebra,46(1),2018,51-61.
122.Peigen Cao,Fang Li,Some conjectures on generalized cluster algebras via the cluster formula and D-matrix pattern,Journal of Algebra,493(2018):57-78.
123.Min Huang,Fang Li,Yichao Yang,On structure of sign-skew-symmetric cluster algebras of geometric type,I:In view of sub-seeds and seed homomorphisms,Science China(Mathematics)Vol.61 No.5:831-854,May 2018.
124.Yanyong Hong and Fang Li.:Virasoro-type Lie conformal algebras of rank 2,Chinese Annals of Mathematics(Series A),39(1),15-32(2018)(in Chinese);Chinese Journal of Contemporary Mathematics,39(1),15-30(2018)(in English).
125.Min Huang,Fang Li and Yichao Yang,Representation rings and derived rings of Nakayama truncated algebras and a viewpoint under monoidal categories,Asian J of Math.Vol.22,No.1,pp.41-74,February 2018.
126.Peigen Cao and Fang Li,Positivity of denominator vectors of skew-symmetric cluster algebras,Journal of Algebra 515(2018)448–455.
127.Min Huang,Fang Li,Unfolding of acyclic sign-skew-symmetric cluster algebras and applications to positivity and F-polynomials,Advances in Mathematics 340(2018):221–283
128.李方,叶昌.广义路代数及其在表示论中的意义.中国科学:数学,2018,48:1595-1614
129.Peigen Cao,Min Huang,Fang Li,A conjecture on$C$-matrices of cluster algebras,Nagoya Mathematical Journal.Online version,(2018),1-10.
130.Peigen Cao and Fang Li,Uniformly column sign-coherence and the existence of maximal green sequences,Journal of Algebraic Combinatorics(2019)50:403-417
131.Peigen Cao,Fang Li,Siyang Liu,Jie Pan,A conjecture on cluster automorphisms of cluster algebras,Electronic Research Archive Volume 27,Pages 1-6(August 28,2019)
132.Min Huang,Fang Li,Totality of acyclic sign-skew-symmetric matrices and some conjectures on cluster algebras,Proceedings of the 7th International Congress of Chinese Mathematicians(Aug.6-Aug.11,2016)ALM 44;Vol.II,pp:53-64,edited by Lizhen Ji,Lo Yang,Shing-Tung Yau,Higher Education Press and International Press,Beijing-Boston,2019
134.Jun Hu,Fang Li,Modified affine Hecke algebras and quiver Hecke algebras of type A,Journal of Algebra 541(2020):219–269
135.Peigen Cao and Fang Li,Unistructurality of cluster algebras,Compositio Mathematica,156(5),May 2020:946-95;Published online by Cambridge Univ.Press:17 April 2020.
中国数学会理事、第十三届中国数学会名词审定委员会委员、中国高等教育学会第四届教育数学专业委员会常务副理事长。