白博峯

油氣開發與集輸工程多相流

高效相變換熱器

異質沸騰的多尺度研究

生物顆粒流

動力推進多相流 ^[1] 

1989.9-1993.7：西安交通大學動力機械系，大學本科

1993.9-1996.1：西安交通大學能源與動力工程學院熱能工程系，工學碩士

1996.3-1999.11：西安交通大學能源與動力工程學院熱能工程系，工學博士

中國工程熱物理學會理事

中國工程熱物理學會多相流專業委員會委員

中國鍋爐壓力容器標準委員會換熱設備分委會委員

1999.12-2002.7：西安交通大學動力工程多相流國家重點實驗室，講師

2002.8-2007.7：西安交通大學動力工程多相流國家重點實驗室，副教授

2007.8-至今：西安交通大學動力工程多相流國家重點實驗室，教授，博導

2002.9-至今：西安交通大學動力工程多相流國家重點實驗室，副主任 ^[1] 

[1] 郭烈錦，白博峯，張西民，張少軍，王鑫，冉新權.油氣集輸的節能減排和安全高效關鍵工藝及裝備，國家發明二等獎.2009

[2] 郭烈錦，白博峯，高暉，陳學俊，張西民，李廣軍，何利民，劉文紅，楊靖，王忠勇，顧漢洋.油氣水多相流動規律與螺旋管流除砂理論及技術.陝西省科學技術獎（自然科學類）一等獎.2003

[3] 郭烈錦，白博峯，張少軍，王鑫，張西民，顧漢洋.油氣水多相流在線監測與輸送工藝和裝備的關鍵技術及其應用.陝西省科學技術獎（技術發明類）一等獎.2007

[4] 郭烈錦，趙亮，魏進家，陳學俊，何銀年，陳斌，白博峯，張西民.氣（汽）液兩相與多相流動力學及傳熱基本規律.高等學校科學技術獎自然科學一等獎.2006

[1] 白博峯,蘇燕兵,嚴俊傑,王俊奇,多進氣道超音速旋流分離與回壓裝置,發明專利,ZL200610043158.2,授權日：2008.07.09

[2] 白博峯,左志濤,甲醇製備氫氣的方法.發明專利,ZL200610104410.6,授權日：2008.05.07

[3] 白博峯,張海濱,劉利,孫慧娟.橫流中湍流氣液摻混流場測試裝置,發明專利,ZL200910020982x,授權日期：2010.8.11

[4] 白博峯,常春,一種超音速凝結與旋流分離裝置,發明專利,ZL200910023458.8,授權日：2011.2.25

[5] 王道富,徐永高,張書平,白博峯,跨音速可控渦氣體除濕裝置,發明專利,申請號：200910081813.7,申請日：2009.04.10；公開號：CN101518709；公開日：2009.09.02

[6] 白博峯,王科,吳革生,徐永高,張書平,一種超音速旋流凝結分離組合噴管,發明專利,申請號：200610105199.X,申請日：2006.12.18；公開號：CN101002992A；公開日：2007.07.25

[7] 白博峯,常春,激波可控超音速氣體除濕裝置,發明專利,申請號：200910024347.9,申請日：2009.10.16

[8] 白博峯,孫慧娟,張海濱,劉利.一種水衝壓發動機強化湍流摻混方法,國防發明專利,申請號200910120276.2,申請日期2009.1.21

[9] 白博峯,呂孝飛,一種基於熱流物流匹配的冷流系統,發明專利,申請號：200910020983.4,申請日：2009.01.20；公開號：CN101476671A；公開日：2009.07.08

[10] 白博峯,劉茂龍.天然氣長輸管道安全投產置換計算軟件,計算機軟件著作,2008SR15575,2008

[11] 郭烈錦,白博峯,王忠勇,一種油氣水多相流流型在線識別方法,發明專利,ZL01115235.4,授權日：2004年4月21日 ^[1] 

[1]Z.Y.Luo,.FXu,B.F.Bai,T.J.Lu.Anti-bodybasedbioparticlecaptureusingmicrofluidicsforglobalhealth,inMicrofluidicApplicationsforHumanHealth(EditedbyU.Demirci,B.Langer,A.Khademhosseini,J.Blander),2010

[2]白博峯編，第四章翅片管式換熱器，換熱器手冊，中國石化出版社，2011 ^[1] 

[1] Chengzhen Sun, Wen-Qiang Lu, Jie Liu, Bofeng Bai. Molecular dynamics simulation of nanofluid’s effective thermal conductivity in high-shear-rate Couette flow. International Journal of Heat and Mass Transfer, 2011. doi:10.1016/j.ijheatmasstransfer.2011.02.005. EI: IP51292517. (SCI源刊)

[2] Bofeng Bai, Huijuan Sun, Haibin Zhang and Li Liu, Numerical Study on Turbulent Mixing of Spray Droplets in Crossflow. AIAA Journal of Propulsion and Power, 2011, 27(1): 132-143. SCI: 711EZ. / EI: 20110213569595

[3] Bofeng Bai, Maolong Liu, Wang Su, Xiaojie Zhang. An experimental study on air-water two-phase flow patterns in pebble beds. ASME Journal of Engineering for Gas Turbines and Power, 2010, 132 (4): 042903. SCI: 549AL / EI: 20104913465899

[4] Sijie Li, Bofeng Bai. Multi vapor embryos nucleation process and spinodal analyses of expandable superheated water system. Nanoscale and Microscale Thermophysical Engineering; 2010, 14(3): 174-185. SCI: 644FM

[5] Z.Y. Luo, F. Xu, T.J. Lu, B.F. Bai. Direct Numerical Simulation of Single Leukocyte Deformation in Microchannel Flow for Disease Diagnosis. Journal of Medical System. 2010. DOI: 10.1007/s10916-010-9502-3.

[6] M. Lin, F. Xu, T.J. Lu, B.F. Bai. A review of heat transfer in human tooth – Experimental characterization and mathematical modeling, Dental Materials. 2010. DOI: 10.1016/j.dental.2010.02.009. SCI: 588PS / EI: 20101712884440.

[7] M. Lin, Q.D. Liu, F. Xu, Kim T, B.F. Bai, T.J. Lu. Thermal property measurement of different human tooth layers using a modified monotonic heating regime method. Infrared Physics & Technology. 2010. DOI: 10.1016/ j.infrared. 2010.09.004. (SCI源刊)

[8] Bofeng Bai, Haibin Zhang, Li Liu, Huijuan Sun. Experimental study on turbulent mixing of spray droplets in crossflow. Experimental Thermal and Fluid Science. 2009, 33(6):1012-1020. SCI: 472WB / EI: 20092812175778

[9] 厲思傑, 白博峯. 可膨脹過熱水系統多氣核演化過程與臨界過熱度分析. 物理學報. 2009, 11, 7596-7602. SCI: 520HV / EI: 000271835200034

[10] L. J. Guo, L. Zhao, D.W. Jing, Y.J. Lu, H.H. Yang, B.F. Bai, X.M. Zhang, L.J. Ma, X.M. Wu. Solar hydrogen production and its development in China. Energy, 2009, 34 (9): 1073-1090. SCI:497QV / EI: 093312257299

[11] Jun Huang, Yanping Huang, Qiuwang Wang, Bofeng Bai. Numerical study on effect of gap width of narrow rectangular channel on critical heat flux enhancement, Nuclear Engineering and Design, 239(2): 320-326. SCI: 408TR / EI: 20090411877318

[12] Jun Lu, Bofeng Bai. Thermosolutal Convection and Solute Segregation during the vertical Bridgman growth of Hg1-xCdxTe single crystals. Journal of Crystal Growth. 2008, 12:38-46. SCI: 399JP / EI: 085211809916

[13] Bofeng Bai, Shaojun Zhang, Liang Zhao, Xin Wang, Hanyang Gu. Online recognition of the multiphase flow regime. Science in China Series E. 2008, 51(8): 1186-1194. SCI: 322UF / EI: 082911377902

[14] M. Lin, Z.Y. Luo, B.F. Bai, F. Xu, T.J. Lu. Fluid mechanics in dentinal microtubules decides the difference between hot and cold tooth pain. Plos ONE. 2011. (In press)

[15] M. Lin, Z.Y. Luo, B.F. Bai, F. Xu, T.J. Lu. Fluid dynamics analysis of shear stress on nerve endings in dentinal microtubule: A quantitative interpretation of hydrodynamic theory, Journal of Mechanics in Medicine and Biology, 2011. (In press)

[16] Z.Y. Luo, F. Xu, T.J. Lu, B.F. Bai. Direct numerical simulation of the detachment of single captured leukocyte under different flow conditions, Journal of Mechanics in Medicine and Biology. 2010. (In press)

[17] B.F. Bai, X.J. Zhang, M.L. Liu, W. Su. Flow Regime Classification and Transition of Flow Boiling Through Porous Channel. Nuclear Engineering and Design, 2011.(Accept)

[18] Yufei Mao, Liejin Guo, Bofeng Bai and Ximin Zhang. Convective heat transfer in helical coils for constant-property and variable-property flows with high Reynolds numbers. Frontiers of Energy and Power Engineering in China. 4(4): 546-552, 2010

[19] Yanpeng Li, Bofeng Bai, Hydrodynamic resistance effect of fluid layer between two immersed approaching particles; China Particuology. 2006, 4(5): 220-228

[20] 毛宇飛, 郭烈錦, 白博峯. 混合長度理論的改進及其在變物性傳熱中的應用. 工程熱物理學報. 2011, 32(1): 58-62. EI: 20110813693216

[21] 劉茂龍, 呂友軍, 白博峯, 蘇望; 閆曉; 肖澤軍. 球牀內氣液兩相流流型及壓降實驗研究. 工程熱物理學報2010, 31(11): 1867-1871. EI: 20104913465899

[22] 張佳, 呂友軍, 張西民, 白博峯. 超聲作用下不同粗糙度表面沸騰換熱實驗研究. 工程熱物理學報. 2010, 31(9): 1524-1527. EI: 20103913261072

[23] 王科; 白博峯. 高速氣液兩相流液膜卷吸夾帶數值模擬研究. 工程熱物理學報. 2010, 31(6): 968-970. EI: 20102613046141

[24] 張海濱, 劉利, 孫慧娟, 白博峯. 橫流中單噴嘴霧化形態與兩相摻混特性研究. 西安交通大學學報. 2010, 44(7): 104-108. EI: 20101612868698

[25] 毛宇飛, 郭烈錦, 甄飛強, 郭萌, 張文斌, 白博峯. 螺旋管內汽水兩相流摩擦阻力特性實驗研究. 工程熱物理學報. 2010, 31(3): 443-446. EI: 20101612868698

[26] 毛宇飛, 郭烈錦, 白博峯. 基於第Reynolds數k-ε模型的超臨界流體對換熱的快速計算模型. 化工學報. 2010, 61(2): 281-288. EI: 20101412827226

[27] 張海濱, 劉利, 孫慧娟, 白博峯, 單噴嘴橫流氣霧兩相流摻混實驗研究. 工程熱物理學報, 2009, 30 (10):1681-1684. EI: 20094512433626

[28] 張曉傑, 蘇望, 白博峯, 閻曉. 多孔結構內流動沸騰流型分類及轉變研究. 工程熱物理學報, 2009, 30 (6): 967-970. EI: 20092612154415

[29] 孫慧娟, 白博峯, 張海濱, 劉利. 噴嘴入射方式對氣體-液滴羣摻混的影響, 固體火箭技術, 2009: 492-495+510. EI: 20101312808313

[30] 孫慧娟, 張海濱, 劉利, 白博峯. 氣體-顆粒摻混的數值模擬研究. 工程熱物理學報. 2009, 30(2): 241-245. EI: 20091011946475

[31] 張曉傑, 朱彥雷, 白博峯, 閻曉, 肖澤軍.多孔球層內沸騰現象與傳熱特性研究. 核動力工程. 2009, 30(1): 45-49+73. EI: 091111955656

[32] 張書平, 吳革生, 於志剛, 李亮, 白博峯. 含濕天然氣超音速凝結研究, 工程熱物理學報, 2008, 30 (11): 1975-1878. EI: 084711720334

[33] 陸軍, 白博峯, 郭烈錦. 二元半導體合金垂直Bridgman晶體生長的熱質對流Ⅰ-原型爐, 人工晶體學報. 2008, 37(3), 561-567. EI: 083111424558

[34] 陸軍, 白博峯, 郭烈錦. 二元合金垂直Bridgman晶體生長過程的熱質對流研究II-三段熱管爐.人工晶體學報. 2008, 37(3):592-597. EI: 20083111424563

[35] 白博峯, 姜茂, 閆鵬. 流動沸騰核態抑制的實驗研究. 化學工程, 2008, 36(9): 15-18. EI: 084411669174

[36] 李贇, 白博峯, 閻曉, 肖澤軍. 微氣泡形成過程及温度影響研究. 工程熱物理學報. 2008, 29(9): 1511-1514. EI: 084411669174

[37] 姜茂, 白博峯. 流動沸騰空穴核化機理的實驗研究. 工程熱物理學報. 2008, 29(3): 434-438. EI: 083811573006

[38] 孫慧娟, 張海濱, 白博峯. 高温燃氣中單個液滴的蒸發特性.西安交通大學學報. 2008, 42(7): 833- 837. EI: 081311170785

[39] 陸軍, 白博峯, 郭烈錦. 垂直Bridgman多組元化合物晶體生長熱質對流.工程熱物理學報. 2008, 29(4): 453-458. EI: 081711223117

[40] Wang Yueshe, Bai Bofeng, Yongli Chen. Numerical Gas-liquid Stratified Flow Regime Model on Evaporation Heat Transfer in Horizontal Micro-fin Tubes. Heat Transfer-Asian Research. 2007, 36(6): 315-323. EI:74010841345

[41] 白博峯, 王彥超, 黃蓉, 肖澤軍. 同心環形管內沸騰兩相流動與傳熱試驗研究. 核動力工程. 2007, 27(6): 48-53. EI: 080411058857

[42] 王躍社, 白博峯, Hiroshi Honda. 水平微肋管內基於氣液環狀流流型的沸騰傳熱理論模型. 工程熱物理學報. 2007, 28(Suppl.1): 177-180. EI: 073410776564

[43] 白博峯, 李恆, 蘇燕兵, 王躍社. 矩形腔內純水凝固過程實驗研究. 工程熱物理學報. 2007, 41(5): 435-438. EI: 072410652526

[44] 黃軍, 王秋旺, 黃彥平, 白博峯. 窄間隙矩形通道的臨界熱流密度解析模型. 動力工程. 2007, 27(6): 923-926. EI: 080211013283

[45] 黃軍, 王秋旺, 黃彥平, 白博峯. 窄間隙矩形通道沸騰傳熱強化判定準則研究. 化學工程. 2007, 35 (11): 13-16. EI: 080211013300

[46] 黃軍, 王秋旺, 黃彥平, 白博峯. 窄間隙矩形通道間隙厚度對傳熱強化影響研究. 核動力工程. 2007, 28(6):48-53. EI: 080411058861

[47] 李恆, 白博峯, 蘇燕兵, 張磊, 郭烈錦. 用NH4Cl-H2O溶液共晶凝固實驗模擬Bridgman法晶體生長過程. 西安交通大學學報. 2007, 41: 1298-1302. EI: 075110983355

[48] 蘇燕兵, 陸軍, 白博峯. 封閉腔內水自然對流換熱數值模擬. 化工學報. 2007, 57(11): 2715-2720. EI: 074910962342

[49] 李彥鵬, 張乾隆, 白博峯. 豎直通道內相鄰氣泡對上升的直接數值模擬.熱能動力工程. 2007, 22(4): 375-379. EI: 73310766899

[50] 白博峯, 王彥超, 肖澤軍. 同心環形管強迫流動與傳熱試驗研究. 化學工程. 2007, 35(6): 12-15. EI: 73010707305

[51] 徐城傑, 白博峯, 王先元, 劉鴻運. 有限深度液體中氣泡破碎的參數影響. 核動力工程. 2006, 271 (S1): 86-90+98. EI: 063110043048

[52] 白博峯, 徐城傑, 姜茂, 劉鴻運, 王先元.有限深度液體中氣泡的破碎條件. 西安交通大學學報. 2006, 40(5): 577-581. EI: 062910013823

[53] 李恆, 白博峯, 陸軍, 郭烈錦. 圓柱腔體內水凝固過程熱對流實驗研究. 工程熱物理學報. 2006, 27(6): 977-980. EI: 070310373003

[54] 陸軍, 李恆, 蘇燕兵, 白博峯. 垂直Bridgman法多組元晶體生長的多場耦合模型. 西安交通大學學報. 2006, 40(5): 582-586. EI: 062910013824

[55] 王俊奇, 徐永高, 薛中天, 徐驚雷, 白博峯. 氣井井筒跨音速氣水分離與旋流排液技術. 石油學報. 2006, 27(5): 119-123. EI: 064710258443

[56] 劉文紅, 郭烈錦, 張西民, 白博峯, 吳鐵軍. 水平管內油氣水三相流分流型阻力特性實驗研究. 工程熱物理學報. 2006, 26(1): 80-83. EI: 05098866601

[57] M. Lin, Z.Y. Luo, B.F. Bai, F. Xu, T.J. Lu. Modeling of nociceptor transduction in tooth pain sensation, Proceeding of 3rd International Conference on Bioinformatics and Biomedical Technology, 2011

[58] Bofeng Bai, Sijie Li1, Xiaofei Lv. Effects of solid wall on Boiling Nucleation by Molecular Dynamics Simulation. Proceedings of the 2nd European Conference on Microfluidics - Microfluidics 2010 - Toulouse, December 8-10, 2010. µFLU10-256

[59] Bofeng Bai,Denghui He, Yong Xu, Canghai Yang, Li Li. Water cut measurement of crude oil slug flow with double-tube capacitance sensor. 6th World Congress on Industrial Process Tomography, September 6-9, 2010, Beijing, China

[60] Sijie Li, Bofeng Bai. Novel Study on Heterogeneous Boiling Nucleation with Solid Wall Condition. 7th International Conference on Multiphase Flow.ICMF 2010, Tampa, FL USA, May 30-June 4, 2010.

[61] Huijuan Sun, Haibin Zhang, Li Liu and Bofeng Bai. Effect of Nozzle Injection Mode on Mixing Characteristics of Evaporating Spray with Crossflow. 7th International Conference on Multiphase Flow. ICMF 2010, Tampa, FL USA, May 30-June 4, 2010.

[62] Bofeng Bai, Sijie Li. Vapor Embryo Nucleation in Near-Wall Region under Pool Boiling Conditions. IHTC14: Proceedings of the International Heat Transfer Conference, August 8-13, 2010, Washington, DC, USA, IHTC14-22142

[63] Bofeng Bai, Maolong Liu, Xiaofei Lv, Wang Su, et al. Single phase and Two-Phase Flow Pressure Drop in Pebble Beds. ICONE18: Proceedings of the 18th International Conference on Nuclear Engineering, May 17-21, 2010, Xi’an, China, ICONE18-30371

[64] Guo Liejin; Bai Bofeng, Zhao Liang; Wang Xin; Gu Hanyang. Online recognition of the multiphase flow regime and study of slug flow in pipeline. 6th International Symposium on Measurement Techniques for Multiphase Flows, Dec. 15-17, 2008, Japan, Plenary lecture Paper. Journal of Physics: Conference Series, 2009: 012047

[65] Lin M, Liu QD, Xu F, Bai BF, Lu TJ. In Vitro investigation of heat transfer in human tooth. 4th International Conference on Advances in Experimental Mechanics Singapore, SINGAPORE, NOV 18-20, 2009. ISTP: BSR97

[66] Bai Bofeng, Liu Maolong, Zhang Xiaojie. An Experimental Study on Air-Water Two-Phase Flow in Pebble Beds. 17th International Conference on Nuclear Engineering (ICONE17).2009. 495-501. ISTP: BRE11

[67] Bai Bofeng, Zhang Xiaojie, Liu Maolong, Su Wang. Flow Regime Classification and Transition of Flow Boiling Through Porous Channel. 17th International Conference on Nuclear Engineering (ICONE17). 2009: 487-493. ISTP: BRE11

[68] Jun Lu, Bofeng Bai, Zhixiang Wen and Liejin Guo. Thermosolutal Convection and Solute Segregation of HgCdTe Alloy during the Vertical Bridgman Single Crystal Growth. HT2008: Proceedings of the ASME Summer Heat Transfer Conference, 1: 705-711. EI:20093812319900 / ISTP:BJH88

[69] Bofeng Bai, Jun Lu, Lei Zhang and Heng Li. Experimental Study on Double-Diffusive Convection during Solidification of NH4Cl-H2O Hypereutectic Solution in Cylindrical Cavity. HT2008: Proceedings of the ASME Summer Heat Transfer Conference, 1: 713-718. EI: 093812319901 / ISTP: BJH88

[70] Li LIU, Haibin ZHANG, Huijuan SUN, Bofeng BAI. Turbulent mixing flow structure of spray droplets in crossflow. 6th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion, 2009.

[71] Haibin ZHANG, Li LIU, Huijuan SUN, Bofeng BAI. Mixing behavior of angled-injected centrifugal spray droplets in crossflow. 6th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion, 2009.

[72] Wen ZX, Lu J, Bai BF. Solute Layers and Double-Diffusive Interfaces during the Solidification of NH4Cl-H2O in Rectangular Cavities. 6th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion, 2009. ISTP: BQA50

[73] X. L. Guo, Bongfeng Bai. Study on length of mixed region during purging of gas pipeline. Asian Symposium on Computational Heat Transfer and Fluid Flow. 2007, Xi'an, China.

[74] Bai Bofeng, Li Heng, Lu Jun, Su Yanbing. Experimental Study on Double-Diffusive Convection during Solidification of NH4Cl-H2O Hypereutectic Solution in Cylindrical Cavity. International Conference on Multiphase Flow, ICMF 2007.2007, Leipzig, Germany. EI: 081711223117

[75] Bai Bofeng, Su Yanbing, Li Heng. Measurement and Simulation of Velocity Field during the Buoyancy-Driven Freezing of Water. 1st Asian Symposium on Computational Heat Transfer and Fluid Flow. 2007, Xi'an, China.

[76] Huang J., Wang Q. W., Huang Y. P., Bai B. F. Analytical model study of critical heat flux in rectangular narrow channel. International Conference on Power Engineering, 2007.1007-1010, ISTP: BHP42

[77] Jun Lu, Bofeng Bai, Liejin Guo. Thermosolutal Convection and Solute Segregation of Binary Alloys in the Vertical Bridgman Single Crystal Growth. Euromat 2007, European Congress on Advanced Materials and Processes. 2007, Nürnberg, Germany.

[78] Bofeng Bai, Liejin Guo, Yanbing Su, Heng Li, Guoxiang Wang. Measurement and Simulation of Velocity Field during the Solidification of NH4Cl-H2O. Euromat 2007, European Congress on Advanced Materials and Processes. 2007, Nürnberg, Germany.

[79] Heng Li, Yanbing Su, Bofeng Bai, Liejin Guo. Effect of Density Extremum on the Solidification of Water in Both Rectangular and Cylindrical Cavity. Euromat 2007, European Congress on Advanced Materials and Processes. 2007, Nürnberg, Germany.

[80] Jun Lu, Bofeng Bai, Liejin Guo, Yanbing Su, Guoxiang Wang. Analysis on Thermosolutal Convection during the Directional Solidification of GeSi Alloy. 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference. 2007, Vancouver, British Columbia, Canada.

[81] LuYun, BAI Bo-feng, Yan Xiao, Xiao Ze-jun. Simulation on Microbubble Generation and Temperature Effection of Argon System. Asian Symposium on Computational Heat Transfer and Fluid Flow. 2007, Xi'an, China.

[82] Bai BF, Zhao L, Wang YS. Characterization of pressure fluctuation in boiling two-phase flow. 13th Int. Heat Transfer Conference. 2006, Sydney, Australia.

[83] Bofeng Bai. Antibody Based Blood Bioparticles Capture and Separation using Micro- fluidics for Global Health. International Workshop on Biomedical Engineering & Bio- mechanics, Xi’an, China, August 20-22, 2010 (Keynote Paper)

[84] Bofeng Bai, Liejin Guo, Shaojun Zhang, et al. Gu. Innovative Techniques of Multiphase Flow in Pipeline System for Oil-Gas Gathering and Transportation with Energy-Saving and Emission-Reduction. 6th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion, Xi’an, China, 11-15 July 2009. Plenary lecture Paper No. PL01. ISTP: BQA50 ^[1]