This study investigates the frequency-temperature behaviors in AT-cut quartz crystal resonators(QCRs).First,the dispersion relations of an infinite quartz plate are obtained through a semi-analytical finite element(SA...This study investigates the frequency-temperature behaviors in AT-cut quartz crystal resonators(QCRs).First,the dispersion relations of an infinite quartz plate are obtained through a semi-analytical finite element(SAFE)analysis,which explicitly reveals the intrinsic frequency-temperature dependence of different vibration modes.Subsequently,we address practical resonator configurations by examining finite quartz plates,where numerical simulations uncover critical interactions between the operational thickness-shear(TS)mode and coupling modes,i.e.,the flexure(F),face-shear(FS),and extension(E)modes.Through the frequency spectra analysis,we demonstrate that both the plate aspect ratio and thermal variations affect mode-coupling behaviors.Unstable frequency-temperature variations(activity dips)are observed at critical resonator dimensions.Validation through the free-vibration eigen-frequency analysis and forced-vibration admittance characterization confirms the stable or unstable states predicted by the frequency spectra.The established framework not only reveals the origin of temperatureinduced activity dips but also provides the crucial design criteria for suppressing the mode-coupling interference in high-stability resonators.展开更多
Scintillator is a key material for the development of X-ray detectors,which has a promising application in medical imaging,security inspection and industrial non-injury detection.The majority of scintillators currentl...Scintillator is a key material for the development of X-ray detectors,which has a promising application in medical imaging,security inspection and industrial non-injury detection.The majority of scintillators currently used in imaging are real-time imaging scintillators,which can cause ionization radiation damage to biological subjects or detection equipment during the imaging process and require complex,highly sensitive detection systems.Therefore,exploring stable,environmentally friendly scintillator materials that can achieve delayed imaging is of significance in the field of imaging.Herein,we devel-oped an X-ray time-lapse imaging scintillator,Sr_(2)Al_(6)O_(11):Dy^(3+)phosphor,which generates stable traps by X-ray irradiation,thus endowing it with excellent persistent luminescence and information storage properties(>42 d).Moreover,traps constructed by X-ray can be repeatedly refilled(>40 times)under UV light and carriers are released in theform of mechanical or thermal excitation when refilling is complete.By constructing the traps in the phosphor during X-ray excitation and using it for repetitive imaging,the detection limit is 74.78 nGy/s,and the spatial imaging resolution is as high as 16 lp/mm.This discovery providesa new idea for the development oftime-delayed X-ray scintillator.展开更多
基金Project supported by the National Key Research and Development Program of China(No.2023YFE0111000)the National Natural Science Foundation of China(Nos.12102183,12172171,and U24A2005)the Shenzhen Science and Technology Program of China(No.JCYJ20230807142004009)。
文摘This study investigates the frequency-temperature behaviors in AT-cut quartz crystal resonators(QCRs).First,the dispersion relations of an infinite quartz plate are obtained through a semi-analytical finite element(SAFE)analysis,which explicitly reveals the intrinsic frequency-temperature dependence of different vibration modes.Subsequently,we address practical resonator configurations by examining finite quartz plates,where numerical simulations uncover critical interactions between the operational thickness-shear(TS)mode and coupling modes,i.e.,the flexure(F),face-shear(FS),and extension(E)modes.Through the frequency spectra analysis,we demonstrate that both the plate aspect ratio and thermal variations affect mode-coupling behaviors.Unstable frequency-temperature variations(activity dips)are observed at critical resonator dimensions.Validation through the free-vibration eigen-frequency analysis and forced-vibration admittance characterization confirms the stable or unstable states predicted by the frequency spectra.The established framework not only reveals the origin of temperatureinduced activity dips but also provides the crucial design criteria for suppressing the mode-coupling interference in high-stability resonators.
基金the National Natural Science Foundation of China(12364044)Yunnan Major Scientific and Technological Projects(202202AG050004,202202AG050016,202302AQ370003)+1 种基金the International Joint Innovation Platform of Yunnan Province(202203AP140004)the Outstanding Youth Project of Yunnan Province Applied Basic Research Project(202401AV070012).
文摘Scintillator is a key material for the development of X-ray detectors,which has a promising application in medical imaging,security inspection and industrial non-injury detection.The majority of scintillators currently used in imaging are real-time imaging scintillators,which can cause ionization radiation damage to biological subjects or detection equipment during the imaging process and require complex,highly sensitive detection systems.Therefore,exploring stable,environmentally friendly scintillator materials that can achieve delayed imaging is of significance in the field of imaging.Herein,we devel-oped an X-ray time-lapse imaging scintillator,Sr_(2)Al_(6)O_(11):Dy^(3+)phosphor,which generates stable traps by X-ray irradiation,thus endowing it with excellent persistent luminescence and information storage properties(>42 d).Moreover,traps constructed by X-ray can be repeatedly refilled(>40 times)under UV light and carriers are released in theform of mechanical or thermal excitation when refilling is complete.By constructing the traps in the phosphor during X-ray excitation and using it for repetitive imaging,the detection limit is 74.78 nGy/s,and the spatial imaging resolution is as high as 16 lp/mm.This discovery providesa new idea for the development oftime-delayed X-ray scintillator.
基金National Natural Science Foundation of China (50802064)Shanghai Committee of Science and Technology (055211010)Shanghai Key Laboratory Program (07DZ22302)
