[1] Ding L L. Analysis and prevention of safety accidents in vehicle hydrogen energy industry chain[J]. Safety Health & Environment, 21, 20-23(2021).

[2] Hu W J, Xiong B B, Wei J T et al. Research on on-line monitoring technology of oil and gas pipeline leakage[J]. Pipeline Technique and Equipment, 33-37(2022).

[3] Baroudi U, Al-Roubaiey A A, Devendiran A. Pipeline leak detection systems and data fusion: a survey[J]. IEEE Access, 7, 97426-97439(2019).

[4] Boon-Brett L, Bousek J, Moretto P. Reliability of commercially available hydrogen sensors for detection of hydrogen at critical concentrations: part Ⅱ:selected sensor test results[J]. International Journal of Hydrogen Energy, 34, 562-571(2009).

[5] Sakthivel M, Weppner W. A portable limiting current solid-state electrochemical diffusion hole type hydrogen sensor device for biomass fuel reactors: engineering aspect[J]. International Journal of Hydrogen Energy, 33, 905-911(2008).

[6] Zhang Y, Su Y Q, Chen J S et al. Progress and prospects of research on hydrogen sensors[J]. Chinese Science Bulletin, 68, 204-219(2023).

[7] Ihokura K, Watson J[M]. The stannic oxide gas sensor: principles and applications(2017).

[8] Butler M A, Ginley D S. Hydrogen sensing with palladium-coated optical fibers[J]. Journal of Applied Physics, 64, 3706-3712(1988).

[9] Yang Y H, Wang H, Yang F L et al. Polarization-maintaining photonic crystal fiber hydrogen sensor based on Sagnac interferometer[J]. Acta Optica Sinica, 34, 0806004(2014).

[10] Chen H C, Shen C Y, Chen X M et al. High-sensitivity optical fiber hydrogen sensor based on the metal organic frameworks of UiO-66-NH2[J]. Optics Letters, 46, 5405-5408(2021).

[11] Lee S, Ryu B, Kim I et al. Temperature- and ambient pressure-independent sensing of hydrogen in fluids using cascaded interferometers incorporated in optical fibers[J]. Advanced Materials Technologies, 8, 2201273(2023).

[12] Sutapun B, Tabib-Azar M, Kazemi A. Pd-coated elastooptic fiber optic Bragg grating sensors for multiplexed hydrogen sensing[J]. Sensors and Actuators B, 60, 27-34(1999).

[13] Dai J X, Yang M H, Yu X et al. Greatly etched fiber Bragg grating hydrogen sensor with Pd/Ni composite film as sensing material[J]. Sensors and Actuators B, 174, 253-257(2012).

[14] Hu X Y, Hu W B, Dai J X et al. Performance of fiber-optic hydrogen sensor based on locally coated π-shifted FBG[J]. IEEE Sensors Journal, 22, 23982-23989(2022).

[15] Buric M, Chen T, Maklad M et al. Multiplexable low-temperature fiber Bragg grating hydrogen sensors[J]. IEEE Photonics Technology Letters, 21, 1594-1596(2009).

[16] Qi L, Jin L, Guan B O. Optically heated fiber Bragg grating in active fibers for low temperature sensing application[J]. Proceedings of SPIE, 8924, 892404(2013).

[17] Miyake K, Kaneko H, Sano M et al. Physical and electrochromic properties of the amorphous and crystalline tungsten oxide thick films prepared under reducing atmosphere[J]. Journal of Applied Physics, 55, 2747-2753(1984).

[18] Sekimoto S, Nakagawa H, Okazaki S et al. A fiber-optic evanescent-wave hydrogen gas sensor using palladium-supported tungsten oxide[J]. Sensors and Actuators B, 66, 142-145(2000).

[19] Caucheteur C, Debliquy M, Lahem D et al. Catalytic fiber Bragg grating sensor for hydrogen leak detection in air[J]. IEEE Photonics Technology Letters, 20, 96-98(2008).

[20] Dai J X, Yang M H, Yang Z et al. Performance of fiber Bragg grating hydrogen sensor coated with Pt-loaded WO3 coating[J]. Sensors and Actuators B, 190, 657-663(2014).

[21] Wang J J, Dai J X, Hu W B et al. Improved performance of fiber-optic hydrogen sensor of porous Pt/WO3 based on ZIF-8[J]. International Journal of Hydrogen Energy, 51, 909-916(2024).

[22] Dai J X, Peng W, Wang G P et al. Improved performance of fiber optic hydrogen sensor based on WO3-Pd2Pt-Pt composite film and self-referenced demodulation method[J]. Sensors and Actuators B, 249, 210-216(2017).

[23] Yaacob M H, Breedon M, Kalantar-zadeh K et al. Absorption spectral response of nanotextured WO3 thin films with Pt catalyst towards H2[J]. Sensors and Actuators B, 137, 115-120(2009).

[24] Dai J X, Ruan H B, Zhou Y C et al. Ultra-high sensitive fiber optic hydrogen sensor in air[J]. Journal of Lightwave Technology, 40, 6583-6589(2022).

[25] Xiang F, Wang G P, Qin Y H et al. Improved performance of fiber Bragg hydrogen sensors assisted by controllable optical heating system[J]. IEEE Photonics Technology Letters, 29, 1233-1236(2017).

[26] Xu B, Chang R, Li P et al. Reflective optical fiber sensor based on light polarization modulation for hydrogen sensing[J]. Journal of the Optical Society of America B, 36, 3471-3478(2019).

[27] Cai S S, González-Vila Á, Zhang X J et al. Palladium-coated plasmonic optical fiber gratings for hydrogen detection[J]. Optics Letters, 44, 4483-4486(2019).

[28] Cao R T, Wu J Y, Liang G Q et al. Functionalized PdAu alloy on nanocones fabricated on optical fibers for hydrogen sensing[J]. IEEE Sensors Journal, 20, 1922-1927(2020).

[29] Alkhabet M M, Yaseen Z M, Eldirderi M M A et al. Palladium/graphene oxide nanocomposite for hydrogen gas sensing applications based on tapered optical fiber[J]. Materials, 15, 8167(2022).

[30] Villatoro J, Monzon-Hernandez D. Low-cost optical fiber refractive-index sensor based on core diameter mismatch[J]. Journal of Lightwave Technology, 24, 1409-1413(2006).

[31] Zhang Y N, Zhang L B, Han B et al. Erbium-doped fiber ring laser with SMS modal interferometer for hydrogen sensing[J]. Optics & Laser Technology, 102, 262-267(2018).

[32] Wen L, Sun Z W, Zheng Q L et al. On-chip ultrasensitive and rapid hydrogen sensing based on plasmon-induced hot electron-molecule interaction[J]. Light: Science & Applications, 12, 76(2023).

[33] Wang G, Feng W L. On-chip Mach-Zehnder interferometer sensor with a double-slot hybrid plasmonic waveguide for high-sensitivity hydrogen detection[J]. Optics Express, 31, 39500-39513(2023).

[34] Xu T S, Zeng Z M, Huang X J et al. Pipeline leak detection based on variational mode decomposition and support vector machine using an interior spherical detector[J]. Process Safety and Environmental Protection, 153, 167-177(2021).

[35] Fletcher R, Chandrasekaran M. SmartBall™: a new approach in pipeline leak detection[C], 117-133(2009).

[36] Guo S X. Study on key technique of small leakage detection based on spherical leak detector for the long-distance oil pipeline[D](2015).

[37] Huang X J, Li Z, Li J et al. Acoustic investigation of high-sensitivity spherical leak detector for liquid-filled pipelines[J]. Applied Acoustics, 174, 107790(2021).

[38] Chen Q, Shen G D, Jiang J C et al. Effect of rubber washers on leak location for assembled pressurized liquid pipeline based on negative pressure wave method[J]. Process Safety and Environmental Protection, 119, 181-190(2018).

[39] Li J, Chen S L, Huang X J et al. Review of leakage monitoring and quasi real-time detection technologies for long gas & oil pipelines[J]. Chinese Journal of Scientific Instrument, 37, 1747-1760(2016).

[40] Lu H F, Iseley T, Behbahani S et al. Leakage detection techniques for oil and gas pipelines: state-of-the-art[J]. Tunnelling and Underground Space Technology, 98, 103249(2020).

[41] Wang Z, Wang H C, Fu L et al. Pipeline detection method based on multiple-pressure sensor and negative pressure wave[J]. Transducer and Microsystem Technologies, 34, 115-118(2015).

[42] Zhang T T, Tan Y F, Zhang X D et al. A novel hybrid technique for leak detection and location in straight pipelines[J]. Journal of Loss Prevention in the Process Industries, 35, 157-168(2015).

[43] Jia Z G, Ren L, Li H N et al. Experimental study of pipeline leak detection based on hoop strain measurement[J]. Structural Control and Health Monitoring, 22, 799-812(2015).

[44] Hou C X, Zhang E H. Pipeline leak detection based on double sensor negative pressure wave[J]. Applied Mechanics and Materials, 313/314, 1225-1228(2013).

[45] Ferrante M, Brunone B, Meniconi S. Wavelets for the analysis of transient pressure signals for leak detection[J]. Journal of Hydraulic Engineering, 133, 1274-1282(2007).

[46] Liu C W, Li Y X, Wang W C et al. Theoretical study and experimental study on leak detection for natural gas pipelines based on acoustic method[J]. Acta Acustica, 38, 372-381(2013).

[47] Zhang J L, Zhang F, Wu W R et al. Experimental study on the leak detection of long distance pipeline by acoustic method[J]. Liaoning Chemical Industry, 42, 1431-1432, 1436(2013).

[48] Yu D Q. Application of infrasonic leakage detection technology in Shengli Oilfield[J]. Oil-Gasfield Surface Engineering, 30, 70-71(2011).

[49] Zheng X L, Wang Q, Xue S et al. Leakage localization for gas pipelines based on delay-and-sum using acoustic signal[J]. Chinese Journal of Scientific Instrument, 40, 241-249(2019).

[50] Jia Z G, Ren L, Li H N et al. Pipeline leak localization based on FBG hoop strain sensors combined with BP neural network[J]. Applied Sciences, 8, 146(2018).

[51] Meng Q X, Shen G T, Yu Y et al. An ultrasonic identification method of noised micro-leakage based on deep residual shrinkage networks[J]. Journal of Applied Acoustics, 41, 964-972(2022).

[52] Ashry I, Mao Y, Wang B W et al. A review of distributed fiber-optic sensing in the oil and gas industry[J]. Journal of Lightwave Technology, 40, 1407-1431(2022).

[53] Zhou Z M, Zhang J, Huang X S et al. Experimental study on distributed optical-fiber cable for high-pressure buried natural gas pipeline leakage monitoring[J]. Optical Fiber Technology, 53, 102028(2019).

[54] Signorini A, Nannipieri T, Gabella L et al. Raman distributed temperature sensor for oil leakage detection in soil: a field trial and future trends[J]. Proceedings of SPIE, 9157, 91578Y(2014).

[55] Xu Y, Li J, Zhang M J et al. Pipeline leak detection using Raman distributed fiber sensor with dynamic threshold identification method[J]. IEEE Sensors Journal, 20, 7870-7877(2020).

[56] Galindez-Jamioy C A, López-Higuera J M. Brillouin distributed fiber sensors: an overview and applications[J]. Journal of Sensors, 2012, 204121(2012).

[57] Inaudi D, Glisic B. Long-range pipeline monitoring by distributed fiber optic sensing[J]. Journal of Pressure Vessel Technology, 132, 011701(2010).

[58] Liu C, Yao D X, Ou Y C et al. Multi-physical field joint monitoring of buried gas pipeline leakage based on BOFDA[J]. Measurement Science and Technology, 33, 105202(2022).

[59] Maraval D, Gabet R, Jaouën Y et al. Slope-assisted BOTDR for pipeline vibration measurements[J]. Proceedings of SPIE, 10323, 103235Z(2017).

[60] Li H J, Zhu H H, Tan D Y et al. Detecting pipeline leakage using active distributed temperature sensing: theoretical modeling and experimental verification[J]. Tunnelling and Underground Space Technology, 135, 105065(2023).

[61] Ren L, Jiang T, Jia Z G et al. Pipeline corrosion and leakage monitoring based on the distributed optical fiber sensing technology[J]. Measurement, 122, 57-65(2018).

[62] Jiang T, Ren L, Wang J J et al. Experimental investigation of fiber Bragg grating hoop strain sensor-based method for sudden leakage monitoring of gas pipeline[J]. Structural Health Monitoring, 20, 3024-3035(2021).

[63] Stajanca P, Chruscicki S, Homann T et al. Detection of leak-induced pipeline vibrations using fiber-optic distributed acoustic sensing[J]. Sensors, 18, 2841(2018).

[64] Yan B Q, Li H, Zhang K Q et al. Quantitative identification and localization for pipeline microleakage by fiber distributed acoustic sensor[J]. Journal of Lightwave Technology, 41, 5460-5467(2023).

[65] Yang T T, Xiao Y B, Ran Z L et al. Design of a weak fiber Bragg grating acoustic sensing system for pipeline leakage monitoring in a nuclear environment[J]. IEEE Sensors Journal, 21, 22703-22711(2021).

[66] Zhang J, Lian Z H, Zhou Z M et al. Numerical and experimental study on leakage detection for buried gas pipelines based on distributed optical fiber acoustic wave[J]. Measurement Science and Technology, 32, 125209(2021).

[67] Chen Z, Zhang C C, Shi B et al. Detecting gas pipeline leaks in sandy soil with fiber-optic distributed acoustic sensing[J]. Tunnelling and Underground Space Technology, 141, 105367(2023).

[68] Wang C, Liu Q W, Chen D et al. Monitoring pipeline leakage using fiber-optic distributed acoustic sensor[J]. Acta Optica Sinica, 39, 1006005(2019).

[69] Zuo J C, Zhang Y, Xu H X et al. Pipeline leak detection technology based on distributed optical fiber acoustic sensing system[J]. IEEE Access, 8, 30789-30796(2020).

[70] Duan Y X, Liang L, Tong X L et al. Application of pipeline leakage detection based on distributed optical fiber acoustic sensor system and convolutional neural network[J]. Journal of Physics D, 57, 105102(2024).

[71] Wang G P, Dai J X, Yang M H. Fiber-optic hydrogen sensors: a review[J]. IEEE Sensors Journal, 21, 12706-12718(2021).

[72] Guo H Y, Tang J G, Li X F et al. On-line writing identical and weak fiber Bragg grating arrays[J]. Chinese Optics Letters, 11, 030602(2013).

[73] He J, Xu B J, Xu X Z et al. Review of femtosecond-laser-inscribed fiber Bragg gratings: fabrication technologies and sensing applications[J]. Photonic Sensors, 11, 203-226(2021).

[74] Dai J X, Yin K, Chen Z N et al. Improved performance of a fiber-optic hydrogen sensor based on a controllable optical heating technology[J]. Optics Letters, 49, 2962-2965(2024).

[75] Adegboye M A, Fung W K, Karnik A. Recent advances in pipeline monitoring and oil leakage detection technologies: principles and approaches[J]. Sensors, 19, 2548(2019).

[76] Zhang X P, Zhang Y X, Wang L et al. Current status and future of research and applications for distributed fiber optic sensing technology[J]. Acta Optica Sinica, 44, 0106001(2024).

[77] Huang L J, Zhou X, Fan X Y et al. Multi-mechanism distributed fiber-optic sensing technology[J]. Acta Optica Sinica, 44, 0106007(2024).

[78] Tejedor J, Macias-Guarasa J, Martins H F et al. Towards detection of pipeline integrity threats using a smart fiber-optic surveillance system: PIT-STOP project blind field test results[J]. Proceedings of SPIE, 10323, 103231K(2017).

[79] Lang X M. Pipeline leak detection and localization based on feature extraction and information fusion[D](2018).

[80] Sun Q, Feng H, Yan X Y et al. Recognition of a phase-sensitivity OTDR sensing system based on morphologic feature extraction[J]. Sensors, 15, 15179-15197(2015).

[81] He Z Y, Liu Q W. Optical fiber distributed acoustic sensors: a review[J]. Journal of Lightwave Technology, 39, 3671-3686(2021).