Single mode-multimode-single mode （SMS） sensor is widely used for parameters measurement, such as bending, dis-placement, temperature, strain, refractive index, etc. Generally, SMS sensor has advantages of simpl...Single mode-multimode-single mode （SMS） sensor is widely used for parameters measurement, such as bending, dis-placement, temperature, strain, refractive index, etc. Generally, SMS sensor has advantages of simple structure, low cost and easy layout, therefore it has become a research hotspot in recent years. In this paper, the multimode fiber with large core is used for manufacturing SMS structure with high sensitivity. Firstly, the multimode fiber with core/cladding diameters of 105/ 125 jitm has access to the system by means of single mode optical fiber. Secondly, SMS device structure is manufactured by welding the eccentric shaft of multimode optical fiber. Afterwards, mode interference effect and spectral response characteristics of the structure of single mode-multimode-single mode optical fiber are analyzed theoretically. Finally, with the help of a wide spectrum light source and a spectrum analyzer, the transmission spectra characteristics of SMS optical fiber with strain is tested. By observing the curve that the wave changes with stress, the sensitivity is calculated and it is consistent with theoretical value .展开更多
Structure, magnetic properties, and thermal stability of ternary Sm1-xTmxCo5 compounds were studied via X-ray diffraction（XRD）, thermal magnetic analysis（TMA）, and magnetic measurements. XRD results show that all ...Structure, magnetic properties, and thermal stability of ternary Sm1-xTmxCo5 compounds were studied via X-ray diffraction（XRD）, thermal magnetic analysis（TMA）, and magnetic measurements. XRD results show that all the compounds have a main phase of hexagonal CaCu5-type crystal structure with small amount of impurity phases; increasing Tm content is associated with contraction of the hexagonal unit cell in the direction of the c axis and expansion of the a and b parameters. TMA results indicate that the Curie temperature（TC） of Sm1-xTmxCo5 compounds gets higher with the increase in Tm content.Magnetic measurements show that both the magnetic anisotropy field（HA） and the magnetization at an applied field of 7 T（M7 T） decrease with the increase of Tm content. However, the thermal stability of both the HAand M7 Tof all the Tm doped compounds is remarkably improved compared with that of the pure SmCo5 compound, leading to the result that both the M7 Tand HAof Sm0.8Tm0.2Co5 .2are higher than those of SmCo5 compound at 473 K, which indicates the good potential of Tm doped compound in the practical applications at elevated temperature.展开更多
This paper presents a long-range displacement measurement method by using a single- multi-single mode （SMS） fiber structure, attached to a flexible plate between two permanent poles and the optical time domain refle...This paper presents a long-range displacement measurement method by using a single- multi-single mode （SMS） fiber structure, attached to a flexible plate between two permanent poles and the optical time domain reflectometer （OTDR）-based interrogator. The SMS fiber structure sensors are prepared with two different configurations, i.e. straight and sinusoidal configurations. It is demonstrated that the displacement sensor can perform a displacement measurement with a range from 0 mm to 150 mm with a resolution of 0.159 mm. The sinusoidal configuration provides a better sensitivity than the straight configuration. The proposed sensor offers a low cost, and it can be implemented for quasi-distributed displacement measurement which is suitable for civil structure monitoring.展开更多
A singlemode-multimode-singlemode （SMS） fiber structure for temperature measurement using an optical time domain reflectometer （OTDR）-based interrogation system is proposed. A temperature measurement range of 40 ...A singlemode-multimode-singlemode （SMS） fiber structure for temperature measurement using an optical time domain reflectometer （OTDR）-based interrogation system is proposed. A temperature measurement range of 40 ℃-195 ℃ with a resolution of 0.12 ℃ and a linearity of 0.992 could be achieved for the multimode fiber （MMF） graded index with a length of 60mm. It was also demonstrated that two-point temperature measurement with two SMS fiber structures as temperature sensors could be made. The proposed temperature measurement system offered a high resolution and also benefited from a simple configuration with a capability of multi-point temperature measurement.展开更多
Nanocrystalline and amorphous La_（2–x）Sm_xMg_（16）Ni＋200wt.% Ni（x=0, 0.1, 0.2, 0.3, 0.4） alloys were prepared by mechanical milling technology. The structures of as-cast and milled alloys were investigated by X...Nanocrystalline and amorphous La_（2–x）Sm_xMg_（16）Ni＋200wt.% Ni（x=0, 0.1, 0.2, 0.3, 0.4） alloys were prepared by mechanical milling technology. The structures of as-cast and milled alloys were investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and transmission electron microscopy（TEM）. Electrochemical performance of the alloy was studied by using an automatic galvanostatic system. The electrochemical impedance spectra（EIS） and Tafel polarization curves were measured by electrochemical workstation. The results indicated that the structures of the as-cast and milled alloys presented a multiphase structure with nanocrystalline and amorphous phase, moreover, transforming from nanocrystalline to amorphous phase with Sm doping. With the increase of Sm content, the maximum discharge capacity of the alloy was decreased from 922.6 to 649.1 m Ah/g, the high-rate discharge ability（HRD） was decreased, the cycle stability was strengthened, and the alloy exhibited excellent electrochemical kinetics. In addition, the charge-transfer resistance（R_（ct）） of alloy was lessened from 0.05874 to 0.02953 ？ and the limiting current density（I_L） was descended from 2.08366 to 1.04592 A/g with increasing Sm content.展开更多
The alloy with nominal composition Sm_2(Fe0.94Ti0.06)17 is prepared by arc-melting, hydrogenation and nitrogenation processes. The Sm_2(Fe0.94Ti0.06)17 alloy has a single phase of Sm_3(Fe, Ti)29 with the Nd_3(Fe, Ti)...The alloy with nominal composition Sm_2(Fe0.94Ti0.06)17 is prepared by arc-melting, hydrogenation and nitrogenation processes. The Sm_2(Fe0.94Ti0.06)17 alloy has a single phase of Sm_3(Fe, Ti)29 with the Nd_3(Fe, Ti)29-type structure. The corresponding hydride phase with the same phase structure of the parent alloy was formed after a hydrogen decrepitation (HD) process at 300℃. The hydrogenation at 800℃ mainly shows a HDDR process. The HD and nitrogenation at 500℃ result in increasing the Curie temperature of the alloy by 72℃ and by 158℃ due to lattice expansions, respectively. The anisotropic and isotropic Sm_3(Fe. Ti)29N_y magnets are obtained after HD, HDDR and the consequent nitrogenation, respectively. The optimum magnetic properties of Sm_3(Fe, Ti)29N_y powders achieved in the above two processes are: (i) B_r=0;82 T, _iH_c=4.48 kA/cm. (BH)_max=54.3 kJ/m^3, (ii) B_r=0.68 T, _iH_c=8.14 kA/cm, (BH)max=66.4 kJ/m^3.展开更多
基金National Natural Science Foundation of China(No.61405127)Shanxi Province Science Foundation for Youths(No.2014021023-1)+1 种基金Scientific and Technologial Innovation Programs of Higher Education Institutions in ShanxiProgram for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi
文摘Single mode-multimode-single mode （SMS） sensor is widely used for parameters measurement, such as bending, dis-placement, temperature, strain, refractive index, etc. Generally, SMS sensor has advantages of simple structure, low cost and easy layout, therefore it has become a research hotspot in recent years. In this paper, the multimode fiber with large core is used for manufacturing SMS structure with high sensitivity. Firstly, the multimode fiber with core/cladding diameters of 105/ 125 jitm has access to the system by means of single mode optical fiber. Secondly, SMS device structure is manufactured by welding the eccentric shaft of multimode optical fiber. Afterwards, mode interference effect and spectral response characteristics of the structure of single mode-multimode-single mode optical fiber are analyzed theoretically. Finally, with the help of a wide spectrum light source and a spectrum analyzer, the transmission spectra characteristics of SMS optical fiber with strain is tested. By observing the curve that the wave changes with stress, the sensitivity is calculated and it is consistent with theoretical value .
基金financially supported by the State Key Development Program of Basic Research of China (No. 2010CB934600)State Key Laboratory of Advanced Metals and Materials (No. 2011-ZD02)the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality (No. 009000543113507)
文摘Structure, magnetic properties, and thermal stability of ternary Sm1-xTmxCo5 compounds were studied via X-ray diffraction（XRD）, thermal magnetic analysis（TMA）, and magnetic measurements. XRD results show that all the compounds have a main phase of hexagonal CaCu5-type crystal structure with small amount of impurity phases; increasing Tm content is associated with contraction of the hexagonal unit cell in the direction of the c axis and expansion of the a and b parameters. TMA results indicate that the Curie temperature（TC） of Sm1-xTmxCo5 compounds gets higher with the increase in Tm content.Magnetic measurements show that both the magnetic anisotropy field（HA） and the magnetization at an applied field of 7 T（M7 T） decrease with the increase of Tm content. However, the thermal stability of both the HAand M7 Tof all the Tm doped compounds is remarkably improved compared with that of the pure SmCo5 compound, leading to the result that both the M7 Tand HAof Sm0.8Tm0.2Co5 .2are higher than those of SmCo5 compound at 473 K, which indicates the good potential of Tm doped compound in the practical applications at elevated temperature.
文摘This paper presents a long-range displacement measurement method by using a single- multi-single mode （SMS） fiber structure, attached to a flexible plate between two permanent poles and the optical time domain reflectometer （OTDR）-based interrogator. The SMS fiber structure sensors are prepared with two different configurations, i.e. straight and sinusoidal configurations. It is demonstrated that the displacement sensor can perform a displacement measurement with a range from 0 mm to 150 mm with a resolution of 0.159 mm. The sinusoidal configuration provides a better sensitivity than the straight configuration. The proposed sensor offers a low cost, and it can be implemented for quasi-distributed displacement measurement which is suitable for civil structure monitoring.
基金This work was supported Technology Research Grant Science Foundation. by Science and Indonesia Toray
文摘A singlemode-multimode-singlemode （SMS） fiber structure for temperature measurement using an optical time domain reflectometer （OTDR）-based interrogation system is proposed. A temperature measurement range of 40 ℃-195 ℃ with a resolution of 0.12 ℃ and a linearity of 0.992 could be achieved for the multimode fiber （MMF） graded index with a length of 60mm. It was also demonstrated that two-point temperature measurement with two SMS fiber structures as temperature sensors could be made. The proposed temperature measurement system offered a high resolution and also benefited from a simple configuration with a capability of multi-point temperature measurement.
基金Project supported by National Natural Science Foundation of China(51371094,51471054)Young Teachers'Training Project,School of Materials and Metallurgy,Inner Mongolia University of Science and Technology(214CY012)
文摘Nanocrystalline and amorphous La_（2–x）Sm_xMg_（16）Ni＋200wt.% Ni（x=0, 0.1, 0.2, 0.3, 0.4） alloys were prepared by mechanical milling technology. The structures of as-cast and milled alloys were investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and transmission electron microscopy（TEM）. Electrochemical performance of the alloy was studied by using an automatic galvanostatic system. The electrochemical impedance spectra（EIS） and Tafel polarization curves were measured by electrochemical workstation. The results indicated that the structures of the as-cast and milled alloys presented a multiphase structure with nanocrystalline and amorphous phase, moreover, transforming from nanocrystalline to amorphous phase with Sm doping. With the increase of Sm content, the maximum discharge capacity of the alloy was decreased from 922.6 to 649.1 m Ah/g, the high-rate discharge ability（HRD） was decreased, the cycle stability was strengthened, and the alloy exhibited excellent electrochemical kinetics. In addition, the charge-transfer resistance（R_（ct）） of alloy was lessened from 0.05874 to 0.02953 ？ and the limiting current density（I_L） was descended from 2.08366 to 1.04592 A/g with increasing Sm content.
基金National Natural Science FOundation of China!59571014National Natural Science FOundation of China!59725103National Natur
文摘The alloy with nominal composition Sm_2(Fe0.94Ti0.06)17 is prepared by arc-melting, hydrogenation and nitrogenation processes. The Sm_2(Fe0.94Ti0.06)17 alloy has a single phase of Sm_3(Fe, Ti)29 with the Nd_3(Fe, Ti)29-type structure. The corresponding hydride phase with the same phase structure of the parent alloy was formed after a hydrogen decrepitation (HD) process at 300℃. The hydrogenation at 800℃ mainly shows a HDDR process. The HD and nitrogenation at 500℃ result in increasing the Curie temperature of the alloy by 72℃ and by 158℃ due to lattice expansions, respectively. The anisotropic and isotropic Sm_3(Fe. Ti)29N_y magnets are obtained after HD, HDDR and the consequent nitrogenation, respectively. The optimum magnetic properties of Sm_3(Fe, Ti)29N_y powders achieved in the above two processes are: (i) B_r=0;82 T, _iH_c=4.48 kA/cm. (BH)_max=54.3 kJ/m^3, (ii) B_r=0.68 T, _iH_c=8.14 kA/cm, (BH)max=66.4 kJ/m^3.
