By detecting and analyzing the variations of energy parameters-torque and temperature field during friction welding, this paper describes that during quasi-stationary heating phase, quite a little mechanical work is t...By detecting and analyzing the variations of energy parameters-torque and temperature field during friction welding, this paper describes that during quasi-stationary heating phase, quite a little mechanical work is transformed into plastic deformation work, thus the efficiency of heat excited by friction is low.展开更多
A set of metallic specimens containing fatigue cracks with different sizes were tested using eddy current pulsed thermography(ECPT),therefore the relations between heating response of the crack area and the crack leng...A set of metallic specimens containing fatigue cracks with different sizes were tested using eddy current pulsed thermography(ECPT),therefore the relations between heating response of the crack area and the crack length was studied.The numerical and experimental results both showed that the increase of the crack length enhanced the crack heating response under specific test conditions.A particular form of calculated response signal,which is linearly related to the crack length,was introduced to provide a quantitative evaluation of crack length.展开更多
Tb^3＋/Eu^3＋ co-doped transparent glass ceramics containing CaF2 nanocrystals were successfully synthesized by high temperature melt-quenching method and subsequent heating. The structure and morphology of the sample...Tb^3＋/Eu^3＋ co-doped transparent glass ceramics containing CaF2 nanocrystals were successfully synthesized by high temperature melt-quenching method and subsequent heating. The structure and morphology of the samples were investigated by X-ray diffraction（XRD）, transmittance electron microscopy（TEM）, high resolution TEM（HRTEM） and selected area electron diffraction（SAED）. The photoluminescence properties and energy transfer process from Tb^3＋ to Eu^3＋ of CaF2：Tb^3＋,Eu^3＋ phosphors were also investigated through excitation spectra and decay curves. In addition, the emission spectra of the glass ceramics in a wide temperature range from 21 to 320 K were recorded under the excitation of 485 nm. It was found that the fluorescence intensity ratios of Tb^3＋ at 545 nm（^5D4→^7F5） to Eu^3＋ at 615 nm（^5D0→^7F2） was highly temperature-dependent with an approximate linear relationship, and the temperature sensitivity was about 0.4%/K. It is expected that the investigated Tb^3＋/Eu^3＋ co-doped CaF2 glass ceramics may have prospective application in optical thermometry.展开更多
LiMgPO4：Tm,Tb phosphors were synthesized using a solid-state diffusion method. Their properties were investigated using X-ray diffraction（XRD）, thermoluminescence（TL）, scanning electron microscopy（SEM）, and OSL...LiMgPO4：Tm,Tb phosphors were synthesized using a solid-state diffusion method. Their properties were investigated using X-ray diffraction（XRD）, thermoluminescence（TL）, scanning electron microscopy（SEM）, and OSL dosimetric techniques. The influence of light stimulation and thermal excitation on the TL and OSL, and the reusability of the phosphors for OSL regenaration were also studied. The LiMgPO4：Tm,Tb phosphor exhibited high sensitivity to ionizing radiation, good signal reusability and a broad linear dose response range（0.1–1000 Gy）. Fading of the OSL signal was about 16% in eight days, after that the intensity kept stable. The excellent luminescent and dosimetric properties of these LiMgPO4：Tm,Tb phosphors enable them to be promising candidates in radiation dosimetry.展开更多
文摘By detecting and analyzing the variations of energy parameters-torque and temperature field during friction welding, this paper describes that during quasi-stationary heating phase, quite a little mechanical work is transformed into plastic deformation work, thus the efficiency of heat excited by friction is low.
基金supported by the Open Foundation of Key Laboratory of Nondestructive Testing of Ministry of Education of Nanchang Aeronautical University
文摘A set of metallic specimens containing fatigue cracks with different sizes were tested using eddy current pulsed thermography(ECPT),therefore the relations between heating response of the crack area and the crack length was studied.The numerical and experimental results both showed that the increase of the crack length enhanced the crack heating response under specific test conditions.A particular form of calculated response signal,which is linearly related to the crack length,was introduced to provide a quantitative evaluation of crack length.
基金Project supported by the National Key Basic Research Program of China(2013CB921800)the National Natural Science Foundation of China(11274299,11374291,11574298,11404321)
文摘Tb^3＋/Eu^3＋ co-doped transparent glass ceramics containing CaF2 nanocrystals were successfully synthesized by high temperature melt-quenching method and subsequent heating. The structure and morphology of the samples were investigated by X-ray diffraction（XRD）, transmittance electron microscopy（TEM）, high resolution TEM（HRTEM） and selected area electron diffraction（SAED）. The photoluminescence properties and energy transfer process from Tb^3＋ to Eu^3＋ of CaF2：Tb^3＋,Eu^3＋ phosphors were also investigated through excitation spectra and decay curves. In addition, the emission spectra of the glass ceramics in a wide temperature range from 21 to 320 K were recorded under the excitation of 485 nm. It was found that the fluorescence intensity ratios of Tb^3＋ at 545 nm（^5D4→^7F5） to Eu^3＋ at 615 nm（^5D0→^7F2） was highly temperature-dependent with an approximate linear relationship, and the temperature sensitivity was about 0.4%/K. It is expected that the investigated Tb^3＋/Eu^3＋ co-doped CaF2 glass ceramics may have prospective application in optical thermometry.
基金Project supported by the National Natural Science Foundation of China(11375278)
文摘LiMgPO4：Tm,Tb phosphors were synthesized using a solid-state diffusion method. Their properties were investigated using X-ray diffraction（XRD）, thermoluminescence（TL）, scanning electron microscopy（SEM）, and OSL dosimetric techniques. The influence of light stimulation and thermal excitation on the TL and OSL, and the reusability of the phosphors for OSL regenaration were also studied. The LiMgPO4：Tm,Tb phosphor exhibited high sensitivity to ionizing radiation, good signal reusability and a broad linear dose response range（0.1–1000 Gy）. Fading of the OSL signal was about 16% in eight days, after that the intensity kept stable. The excellent luminescent and dosimetric properties of these LiMgPO4：Tm,Tb phosphors enable them to be promising candidates in radiation dosimetry.
