This study investigates the effect of BaHfO_(3)(BHO)addition on the optical properties of YBa_2Cu_(3)O_(7-δ)(YBCO)superconducting thin films using spectroscopic ellipsometry.Through Raman spectroscopy and SEM analysi...This study investigates the effect of BaHfO_(3)(BHO)addition on the optical properties of YBa_2Cu_(3)O_(7-δ)(YBCO)superconducting thin films using spectroscopic ellipsometry.Through Raman spectroscopy and SEM analysis,optimal 10-min Ar ion etching effectively removes surface a-axis-oriented grains and Ba–Cu–O impurities,enhancing surface quality.Optical conductivity analysis reveals a doping-dependent evolution:10%BHO doping maximizes free carrier density and interband transition efficiency,attributed to optimized Cu–O bond contraction and reduced lattice distortions.Higher doping induces defect clustering,carrier scattering,and redshifted transitions due to lattice expansion.Dielectric function and loss function analyses confirm enhanced plasmonic behavior and flux pinning at 10%doping,while excessive doping degrades electronic transitions.These results highlight the critical role of controlled BHO addition and surface treatment in tailoring the optical and superconducting properties of YBCO,offering insights into the interplay among doping,carrier dynamics,and electronic structure in high-temperature superconductors(HTS).展开更多
The development of the sensor suitable for measuring large load stress to the anchor cable becomes an important task in bridge construction and maintenance. Therefore, a new type of optical fiber sensor was developed ...The development of the sensor suitable for measuring large load stress to the anchor cable becomes an important task in bridge construction and maintenance. Therefore, a new type of optical fiber sensor was developed in the laboratory - optical fiber grating sensor for force measurement of anchor cable （OFBFMAC）. No similar report about this kind of sensor has been found up to now in China and other countries. This sensor is proved to be an effective way of monitoring in processes of anchor cable installation, cable cutting, cable force regulation, etc, with the accurate and repeatable measuring results. Its successful application in the tie bar cable force safety monitoring for Wuhan Qingchuan bridge is a new exploration of optical fiber grating sensing technology in bridge tie bar monitoring system.展开更多
Directly buried metal optical cable is a form of erecting optical fiber ring network communication system in wind farms. Although the directly buried optical cable is much less than the overhead optical cable affected...Directly buried metal optical cable is a form of erecting optical fiber ring network communication system in wind farms. Although the directly buried optical cable is much less than the overhead optical cable affected by lightning, sometimes lightning damaging optical cable and flashover discharge accidents of optical cable port occurred. In this paper, the amplitude spectrum of lightning wave, the breakdown depth and breakdown distance of lightning wave to soil, the metal components of optical cable port and the impedance characteristics of grounding wire are systematically analyzed, and the prevention methods of directly buried optical cable in wind farm to avoid lightning damage are proposed.展开更多
With the development of high speed railway traffic, the structure health monitoring for high-speed rail is necessary due to the safety issue. Optical fiber sensing technology is one of the options to solve it. Stress ...With the development of high speed railway traffic, the structure health monitoring for high-speed rail is necessary due to the safety issue. Optical fiber sensing technology is one of the options to solve it. Stress vector information is the important index to make more reasonable judgments about railway safety. However, information sensed by lots of commercial optical sensors is scalar. According to the stress filed distribution of rail, this paper proposes a new type of stress vector sensor based on optical fiber sensing cable(OFSC) with a symmetrical seven optical fibers structure and analyzes the relations between angle resolution and distance between adjacent of optical fibers through finite-element software(ANSYS) simulation. Through reasonable distance configuration, the angle resolution of the OFSC can be improved, and thus stress vector information, including the stress magnitude and the angle of stress, can be more accurately obtained. The simulation results are helpful to configure OFSC for angle resolution improvement in actual practice, and increase the safety factor in high speed railway structure health monitoring.展开更多
This paper introduces a new-developed mine fire-resistant optical fiber cable (OFC)KL5004,its structural characteristics, main feature, the theory about fire resistance and its application in high output and efficienc...This paper introduces a new-developed mine fire-resistant optical fiber cable (OFC)KL5004,its structural characteristics, main feature, the theory about fire resistance and its application in high output and efficiency mine.展开更多
1. Southern Coastal Optical Cable Engineering Project. The cable was completed and put into operation in 1992, and has a total length of 2,800km, starting from Nanjing in the north, via Shanghai, Hangzhou, Fuzhou, Xia...1. Southern Coastal Optical Cable Engineering Project. The cable was completed and put into operation in 1992, and has a total length of 2,800km, starting from Nanjing in the north, via Shanghai, Hangzhou, Fuzhou, Xiamen, Huizhou, leading to Guangzhou in the south, covering Jiangsu, Shanghai, Zhejiang, Fujian and Guangdong. The whole line has展开更多
A key project of the state, the Beijing-Taiyuan-Xi’an optical cable communications trunk, is one of the 22 optical cables planned to be laid by the Ministry of Post and Telecommunications during the Eighth Five Year....A key project of the state, the Beijing-Taiyuan-Xi’an optical cable communications trunk, is one of the 22 optical cables planned to be laid by the Ministry of Post and Telecommunications during the Eighth Five Year. Plan. This communication cable trunk covers a distance of 1771 km, starting from Beijing and going via Hebei and Shanxi to Xi’an in Shaanxi, linking two provincial capitals, one municipality directly under the jurisdiction of the central government, seven other cities and 32 counties.展开更多
Distributed temperature sensing(DTS)using heated cables has been recently developed for distributed monitoring of in-situ soil moisture content.In this method,the thermal and electrical properties of heated cables hav...Distributed temperature sensing(DTS)using heated cables has been recently developed for distributed monitoring of in-situ soil moisture content.In this method,the thermal and electrical properties of heated cables have a significant influence on the measurement accuracy of soil moisture content.In this paper,the performances of two heated cables,i.e.the carbon-fiber heated cable(CFHC)and the metalnet heated cable(MNHC),are studied in the laboratory.Their structures,uniformity in the axial direction,measurement accuracy and suitability are evaluated.The test results indicate that the MNHC has a better uniformity in the axial direction than CFHC.Both CFHC and MNHC have high measurement accuracy.The CFHC is more suitable for short-distance measurement(500 m),while the MNHC can be used for longdistance measurement(>500 m).展开更多
Moisture content is a fundamental physical index that quantifies soil property and is closely associatedwith the hydrological, ecological and engineering behaviors of soil. To measure in-situ soil moisturecontents, a ...Moisture content is a fundamental physical index that quantifies soil property and is closely associatedwith the hydrological, ecological and engineering behaviors of soil. To measure in-situ soil moisturecontents, a distributed measurement system for in-situ soil moisture content （SM-DTS） is introduced.The system is based on carbon-fiber heated cable （CFHC） technology that has been developed to enhancethe measuring accuracy of in-situ soil moisture content. Using CFHC technique, a temperature characteristicvalue （Tt） can be defined from temperatureetime curves. A relationship among Tt, soil thermalimpedance coefficient and soil moisture content is then established in laboratory. The feasibility of theSM-DTS technology to provide distributed measurements of in-situ soil moisture content is verifiedthrough field tests. The research reported herein indicates that the proposed SM-DTS is capable ofmeasuring in-situ soil moisture content over long distances and large areas.展开更多
A new zero-dimensional（0D） thioborate Ba_9B_3GaS_（15） has been discovered by conventional high-temperature solid-state reaction. The compound crystallizes in orthorhombic space group Pbca with a = 8.4759（8）,b = ...A new zero-dimensional（0D） thioborate Ba_9B_3GaS_（15） has been discovered by conventional high-temperature solid-state reaction. The compound crystallizes in orthorhombic space group Pbca with a = 8.4759（8）,b = 22.266（2）,c = 31.426（3） ？,V = 5931（2） ？~3,Z = 8,Mr = 1819.11,Dc = 4.075 g/cm3,μ = 13.684 mm^（-1）,F（000） = 6320,S = 1.034,（Δρ）max = 5.039,（Δρ）min = –5.409 e/？~3,the final R = 0.0362 and w R = 0.1053 for 19243 observed reflections with I 〉 2σ（I）. The structure is constructed by discrete [BS_3]^（3–） trigonal planes and isolated [GaS_4]^（5–） tetrahedra with Ba^（2＋） and isolated S^（2–） filled among them. The UV-Vis-near-IR spectrum reveals a wide band gap of 3.15 eV that agrees with the electronic structure calculation.展开更多
The effect of high-temperature annealing on A1N thin film grown by metalorganic chemical vapor deposition was investigated using atomic force microscopy, Raman spectroscopy, and deep ultra-violet photoluminescence （P...The effect of high-temperature annealing on A1N thin film grown by metalorganic chemical vapor deposition was investigated using atomic force microscopy, Raman spectroscopy, and deep ultra-violet photoluminescence （PL） with the excitation wavelength as short as ~ 177 nm. Annealing experiments were carded out in either N2 or vacuum atmosphere with the annealing temperature ranging from 1200 ℃ to 1600 ℃. It is found that surface roughness reduced and compres- sive strain increased with the annealing temperature increasing in both annealing atmospheres. As to optical properties, a band-edge emission peak at 6.036 eV and a very broad emission band peaking at about 4.7 eV were observed in the photoluminescence spectrum of the as-grown sample. After annealing, the intensity of the band-edge emission peak varied with the annealing temperature and atmosphere. It is also found that a much stronger emission band ranging from 2.5 eV to 4.2 eV is superimposed on the original spectra by annealing in either N2 or vacuum atmosphere. We attribute these deep-level emission peaks to the VAL--ON complex in the A1N material.展开更多
Due to the increasing demand of replacing large capacity overhead lines with underground cables in Korea, KEPCO （Korea Electric Power Corporation） and LS Cable （LS Cable ＆ System） have developed 345 kV optical fi...Due to the increasing demand of replacing large capacity overhead lines with underground cables in Korea, KEPCO （Korea Electric Power Corporation） and LS Cable （LS Cable ＆ System） have developed 345 kV optical fiber composite XLPE （cross-linked polyethylene） 2,500 mm2 cable system. This system has been installed in Cheongna district of Incheon city. KEPCO and LS Cable are also planning to build the cooling system in a tunnel in order to reduce the ambient temperature caused by currents. In this paper, the process of development, field installation, and final inspection test of the complete system will be described.展开更多
This study proposes a nondestructive optical imaging-based three-dimensional(3D)reconstruction method to analyse electrical tree propagation in polypropylene(PP)cable insulation under mechanical bending.The technique ...This study proposes a nondestructive optical imaging-based three-dimensional(3D)reconstruction method to analyse electrical tree propagation in polypropylene(PP)cable insulation under mechanical bending.The technique combines focus-stacked optical imaging with a feature fusion algorithm to segment in-focus regions across depth layers,enabling 3D reconstruction of electrical trees in PP homopolymer(PPH),block copolymer(PPB)and elastomer-blended(PP/TPE)samples.The results demonstrate that mechanical bending accelerates electrical tree propagation in PPH,and that degradation channels transition from a branch-like to a straight-stick morphology,tending to grow directionally towards stretched regions.With a bending radius of 10 mm,the breakdown time drops from 297.0 min for the undeformed samples to 6.3 min.PPB and PP/TPE delay the time to breakdown by 70.6%and 171.2%,respectively,highlighting their superior resistance under bending stress,which is attributed to maintaining elasticity rather than yield deformation under bending stresses.This study provides a novel tool for evaluating the electrical tree resistance of PP composites under the mechanical stress,guiding the development of recyclable high-voltage direct current cable insulation.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52172271,12374378,52307026,and 52477022)the National Key Research and Development Program of China(Grant No.2022YFE03150200)Shanghai Science and Technology Innovation Program(Grant No.23511101600)。
文摘This study investigates the effect of BaHfO_(3)(BHO)addition on the optical properties of YBa_2Cu_(3)O_(7-δ)(YBCO)superconducting thin films using spectroscopic ellipsometry.Through Raman spectroscopy and SEM analysis,optimal 10-min Ar ion etching effectively removes surface a-axis-oriented grains and Ba–Cu–O impurities,enhancing surface quality.Optical conductivity analysis reveals a doping-dependent evolution:10%BHO doping maximizes free carrier density and interband transition efficiency,attributed to optimized Cu–O bond contraction and reduced lattice distortions.Higher doping induces defect clustering,carrier scattering,and redshifted transitions due to lattice expansion.Dielectric function and loss function analyses confirm enhanced plasmonic behavior and flux pinning at 10%doping,while excessive doping degrades electronic transitions.These results highlight the critical role of controlled BHO addition and surface treatment in tailoring the optical and superconducting properties of YBCO,offering insights into the interplay among doping,carrier dynamics,and electronic structure in high-temperature superconductors(HTS).
基金Supported by the National Natural Science Foundation ofChina (60537050)
文摘The development of the sensor suitable for measuring large load stress to the anchor cable becomes an important task in bridge construction and maintenance. Therefore, a new type of optical fiber sensor was developed in the laboratory - optical fiber grating sensor for force measurement of anchor cable （OFBFMAC）. No similar report about this kind of sensor has been found up to now in China and other countries. This sensor is proved to be an effective way of monitoring in processes of anchor cable installation, cable cutting, cable force regulation, etc, with the accurate and repeatable measuring results. Its successful application in the tie bar cable force safety monitoring for Wuhan Qingchuan bridge is a new exploration of optical fiber grating sensing technology in bridge tie bar monitoring system.
基金Supported by Regional Lightning Protection Engineering Technology Research and Development Project in Guangdong Yuedian Dianbai Wind Farm (GDW-PK-21022 Phase II)。
文摘Directly buried metal optical cable is a form of erecting optical fiber ring network communication system in wind farms. Although the directly buried optical cable is much less than the overhead optical cable affected by lightning, sometimes lightning damaging optical cable and flashover discharge accidents of optical cable port occurred. In this paper, the amplitude spectrum of lightning wave, the breakdown depth and breakdown distance of lightning wave to soil, the metal components of optical cable port and the impedance characteristics of grounding wire are systematically analyzed, and the prevention methods of directly buried optical cable in wind farm to avoid lightning damage are proposed.
文摘With the development of high speed railway traffic, the structure health monitoring for high-speed rail is necessary due to the safety issue. Optical fiber sensing technology is one of the options to solve it. Stress vector information is the important index to make more reasonable judgments about railway safety. However, information sensed by lots of commercial optical sensors is scalar. According to the stress filed distribution of rail, this paper proposes a new type of stress vector sensor based on optical fiber sensing cable(OFSC) with a symmetrical seven optical fibers structure and analyzes the relations between angle resolution and distance between adjacent of optical fibers through finite-element software(ANSYS) simulation. Through reasonable distance configuration, the angle resolution of the OFSC can be improved, and thus stress vector information, including the stress magnitude and the angle of stress, can be more accurately obtained. The simulation results are helpful to configure OFSC for angle resolution improvement in actual practice, and increase the safety factor in high speed railway structure health monitoring.
文摘This paper introduces a new-developed mine fire-resistant optical fiber cable (OFC)KL5004,its structural characteristics, main feature, the theory about fire resistance and its application in high output and efficiency mine.
文摘1. Southern Coastal Optical Cable Engineering Project. The cable was completed and put into operation in 1992, and has a total length of 2,800km, starting from Nanjing in the north, via Shanghai, Hangzhou, Fuzhou, Xiamen, Huizhou, leading to Guangzhou in the south, covering Jiangsu, Shanghai, Zhejiang, Fujian and Guangdong. The whole line has
文摘A key project of the state, the Beijing-Taiyuan-Xi’an optical cable communications trunk, is one of the 22 optical cables planned to be laid by the Ministry of Post and Telecommunications during the Eighth Five Year. Plan. This communication cable trunk covers a distance of 1771 km, starting from Beijing and going via Hebei and Shanxi to Xi’an in Shaanxi, linking two provincial capitals, one municipality directly under the jurisdiction of the central government, seven other cities and 32 counties.
基金The financial supports provided by the National Natural Science Foundation of China(Grant Nos.41230636,41372265,41427801)National Basic Research Program of China(973 Project)(Grant No.2011CB710605)
文摘Distributed temperature sensing(DTS)using heated cables has been recently developed for distributed monitoring of in-situ soil moisture content.In this method,the thermal and electrical properties of heated cables have a significant influence on the measurement accuracy of soil moisture content.In this paper,the performances of two heated cables,i.e.the carbon-fiber heated cable(CFHC)and the metalnet heated cable(MNHC),are studied in the laboratory.Their structures,uniformity in the axial direction,measurement accuracy and suitability are evaluated.The test results indicate that the MNHC has a better uniformity in the axial direction than CFHC.Both CFHC and MNHC have high measurement accuracy.The CFHC is more suitable for short-distance measurement(500 m),while the MNHC can be used for longdistance measurement(>500 m).
基金The financial supports provided by the National Natural Science Foundation of China(Grant Nos.41230636,41372265,41427801)National Basic Research Program of China(973 Project)(Grant No.2011CB710605)
文摘Moisture content is a fundamental physical index that quantifies soil property and is closely associatedwith the hydrological, ecological and engineering behaviors of soil. To measure in-situ soil moisturecontents, a distributed measurement system for in-situ soil moisture content （SM-DTS） is introduced.The system is based on carbon-fiber heated cable （CFHC） technology that has been developed to enhancethe measuring accuracy of in-situ soil moisture content. Using CFHC technique, a temperature characteristicvalue （Tt） can be defined from temperatureetime curves. A relationship among Tt, soil thermalimpedance coefficient and soil moisture content is then established in laboratory. The feasibility of theSM-DTS technology to provide distributed measurements of in-situ soil moisture content is verifiedthrough field tests. The research reported herein indicates that the proposed SM-DTS is capable ofmeasuring in-situ soil moisture content over long distances and large areas.
基金Supported by the National Natural Science Foundation of China(21233009,21225104,91422303,21301175 and 21171168)
文摘A new zero-dimensional（0D） thioborate Ba_9B_3GaS_（15） has been discovered by conventional high-temperature solid-state reaction. The compound crystallizes in orthorhombic space group Pbca with a = 8.4759（8）,b = 22.266（2）,c = 31.426（3） ？,V = 5931（2） ？~3,Z = 8,Mr = 1819.11,Dc = 4.075 g/cm3,μ = 13.684 mm^（-1）,F（000） = 6320,S = 1.034,（Δρ）max = 5.039,（Δρ）min = –5.409 e/？~3,the final R = 0.0362 and w R = 0.1053 for 19243 observed reflections with I 〉 2σ（I）. The structure is constructed by discrete [BS_3]^（3–） trigonal planes and isolated [GaS_4]^（5–） tetrahedra with Ba^（2＋） and isolated S^（2–） filled among them. The UV-Vis-near-IR spectrum reveals a wide band gap of 3.15 eV that agrees with the electronic structure calculation.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB619306)863 Program of China(Grant No.2011AA03A101)
文摘The effect of high-temperature annealing on A1N thin film grown by metalorganic chemical vapor deposition was investigated using atomic force microscopy, Raman spectroscopy, and deep ultra-violet photoluminescence （PL） with the excitation wavelength as short as ~ 177 nm. Annealing experiments were carded out in either N2 or vacuum atmosphere with the annealing temperature ranging from 1200 ℃ to 1600 ℃. It is found that surface roughness reduced and compres- sive strain increased with the annealing temperature increasing in both annealing atmospheres. As to optical properties, a band-edge emission peak at 6.036 eV and a very broad emission band peaking at about 4.7 eV were observed in the photoluminescence spectrum of the as-grown sample. After annealing, the intensity of the band-edge emission peak varied with the annealing temperature and atmosphere. It is also found that a much stronger emission band ranging from 2.5 eV to 4.2 eV is superimposed on the original spectra by annealing in either N2 or vacuum atmosphere. We attribute these deep-level emission peaks to the VAL--ON complex in the A1N material.
文摘Due to the increasing demand of replacing large capacity overhead lines with underground cables in Korea, KEPCO （Korea Electric Power Corporation） and LS Cable （LS Cable ＆ System） have developed 345 kV optical fiber composite XLPE （cross-linked polyethylene） 2,500 mm2 cable system. This system has been installed in Cheongna district of Incheon city. KEPCO and LS Cable are also planning to build the cooling system in a tunnel in order to reduce the ambient temperature caused by currents. In this paper, the process of development, field installation, and final inspection test of the complete system will be described.
基金supported by National Natural Science Foundation of China(Grants 52477151 and 52522702).
文摘This study proposes a nondestructive optical imaging-based three-dimensional(3D)reconstruction method to analyse electrical tree propagation in polypropylene(PP)cable insulation under mechanical bending.The technique combines focus-stacked optical imaging with a feature fusion algorithm to segment in-focus regions across depth layers,enabling 3D reconstruction of electrical trees in PP homopolymer(PPH),block copolymer(PPB)and elastomer-blended(PP/TPE)samples.The results demonstrate that mechanical bending accelerates electrical tree propagation in PPH,and that degradation channels transition from a branch-like to a straight-stick morphology,tending to grow directionally towards stretched regions.With a bending radius of 10 mm,the breakdown time drops from 297.0 min for the undeformed samples to 6.3 min.PPB and PP/TPE delay the time to breakdown by 70.6%and 171.2%,respectively,highlighting their superior resistance under bending stress,which is attributed to maintaining elasticity rather than yield deformation under bending stresses.This study provides a novel tool for evaluating the electrical tree resistance of PP composites under the mechanical stress,guiding the development of recyclable high-voltage direct current cable insulation.
