Bi4Si3O12 (BSO) is an excellent scintillation crystal,and is becoming the desirable candidate for dual-readout calorimeters in high-energy physics.In this work,high quality BSO crystals are successfully grown by the m...Bi4Si3O12 (BSO) is an excellent scintillation crystal,and is becoming the desirable candidate for dual-readout calorimeters in high-energy physics.In this work,high quality BSO crystals are successfully grown by the modified Bridgman method.For the first time,its mechanical and thermal properties are investigated and compared with those of the famous scintillation crystal Bi4 Ge3O12 (BGO).The Vickers hardness and fracture toughness of BSO crystal are higher than those of BGO crystal.Its specific heat,thermal diffusivity and thermal conductivity are measured to be 0.319 J·g^(-1) K^(-1),1.54mm2.s^(-1) and 3.29 W·m^(-1) K^(-1) at 298K,respectively.The average thermal expansion coeffcient is calculated to be 7.07 × 10^(-6) K^(-1) from 300 to 1173K.Compared with BGO crystal,BSO crystal possesses larger specific heat,thermal conductivity and smaller thermal expansion.These results indicate that BSO crystals possess better mechanical and thermal properties,which will benefit its practical applications.展开更多
The mechanical properties of Si-doped(111)GaAs crystal for solar cells are investigated by means of a microindentation technique.Vickers'microhardness Hv exhibits a nonlinear relationship with the applied load.In ...The mechanical properties of Si-doped(111)GaAs crystal for solar cells are investigated by means of a microindentation technique.Vickers'microhardness Hv exhibits a nonlinear relationship with the applied load.In the range of 0.1–1 kg,Hv is decreased from 5.59 GPa to 5.03 GPa.Such a phenomenon is explained on the basis of indenter penetration.The Hv value can effectively be presumed by Kick's law,and Meyer's index n is calculated to be 1.90.For the fracture toughness Kc of the GaAs crystal,it also displays nonlinear behavior related to the applied load,which is caused by energy dissipation during the development process of cracks on the wafer.展开更多
Rare-earth doped inorganic ferroelectrics are considered as novel photochromic materials,with potential applications for optical switch and information storage(K0.5Na0.5)1–xEuxNbO3(KNN:xEu)ceramics were prepared by h...Rare-earth doped inorganic ferroelectrics are considered as novel photochromic materials,with potential applications for optical switch and information storage(K0.5Na0.5)1–xEuxNbO3(KNN:xEu)ceramics were prepared by high temperature calcination,with precursor powder obtained by hydrothermal method.Strong red emission at 615 nm was observed which corresponds to the 5D0→7F2 transition of Eu3+under excitation of 465 nm.Under UV light irradiation for 3 min,the color of the ceramics turned from milky white to dark gray.The colored samples returned to the original color when heated at 200℃for 10 min,showing strong photochromic behavior.Meanwhile,the luminescence intensity of Eu3+can be tuned without obvious degradation by alternating UV light and heat stimulus.Upon UV light irradiation,large luminescence modulation ratio(ΔRt)up to 83.9%was achieved for KNN:0.06Eu,indicating good luminescence switching behavior.A possible mechanism for non-radiative energy transfer from the luminescent center to the color center was proposed according to their luminescent behavior.展开更多
Objective To assess whether the use of Tanreqing(TRQ)Injection could show improvements in time to extubation,intensive care unit(ICU)mortality,ventilator-associated events(VAEs)and infection-related ventilator associa...Objective To assess whether the use of Tanreqing(TRQ)Injection could show improvements in time to extubation,intensive care unit(ICU)mortality,ventilator-associated events(VAEs)and infection-related ventilator associated complication(IVAC)among patients receiving mechanical ventilation(MV).Methods A time-dependent cox-regression analysis was conducted using data from a well-established registry of healthcare-associated infections at ICUs in China.Patients receiving continuous MV for 3 days or more were included.A time-varying exposure definition was used for TRQ Injection,which were recorded on daily basis.The outcomes included time to extubation,ICU mortality,VAEs and IVAC.Time-dependent Cox models were used to compare the clinical outcomes between TRQ Injection and non-use,after controlling for the influence of comorbidities/conditions and other medications with both fixed and time-varying covariates.For the analyses of time to extubation and ICU mortality,Fine-Gray competing risk models were also used to measure competing risks and outcomes of interest.Results Overall,7,685 patients were included for the analyses of MV duration,and 7,273 patients for the analysis of ICU mortality.Compared to non-use,patients with TRQ Injection had a lower risk of ICU mortality(Hazards ratios(HR)0.761,95%CI,0.581–0.997),and was associated with a higher hazard for time to extubation(HR 1.105,95%CI,1.005–1.216),suggesting a beneficial effect on shortened time to extubation.No significant differences were observed between TRQ Injection and non-use regarding VAEs(HR 1.057,95%CI,0.912–1.225)and IVAC(HR 1.177,95%CI,0.929–1.491).The effect estimates were robust when using alternative statistic models,applying alternative inclusion and exclusion criteria,and handling missing data by alternative approaches.Conclusion Our findings suggested that the use of TRQ Injection might lower mortality and improve time to extubation among patients receiving MV,even after controlling for the factor that the use of TRQ changed over time.展开更多
基金Supported by National Natural Science Foundation of China under Grant Nos 50972093 and 51002097the National Basic Research Program of China under Grant No 2011CB612310+1 种基金Shanghai Science and Technology Committee(Nos 10XD1403800,11JC1412400)the Shanghai Education Commission(Nos J51504,11YZ223).
文摘Bi4Si3O12 (BSO) is an excellent scintillation crystal,and is becoming the desirable candidate for dual-readout calorimeters in high-energy physics.In this work,high quality BSO crystals are successfully grown by the modified Bridgman method.For the first time,its mechanical and thermal properties are investigated and compared with those of the famous scintillation crystal Bi4 Ge3O12 (BGO).The Vickers hardness and fracture toughness of BSO crystal are higher than those of BGO crystal.Its specific heat,thermal diffusivity and thermal conductivity are measured to be 0.319 J·g^(-1) K^(-1),1.54mm2.s^(-1) and 3.29 W·m^(-1) K^(-1) at 298K,respectively.The average thermal expansion coeffcient is calculated to be 7.07 × 10^(-6) K^(-1) from 300 to 1173K.Compared with BGO crystal,BSO crystal possesses larger specific heat,thermal conductivity and smaller thermal expansion.These results indicate that BSO crystals possess better mechanical and thermal properties,which will benefit its practical applications.
基金by the Shanghai Science and Technology Committee under Grant Nos 09530500800 and 10520501200the National Natural Science Foundation of China under Grant No 51002096+1 种基金the Innovative Research Project of Shanghai Education Commission under Grant No 11YZ222the Key Disciplines of Shanghai Municipality under Grant No J51504.
文摘The mechanical properties of Si-doped(111)GaAs crystal for solar cells are investigated by means of a microindentation technique.Vickers'microhardness Hv exhibits a nonlinear relationship with the applied load.In the range of 0.1–1 kg,Hv is decreased from 5.59 GPa to 5.03 GPa.Such a phenomenon is explained on the basis of indenter penetration.The Hv value can effectively be presumed by Kick's law,and Meyer's index n is calculated to be 1.90.For the fracture toughness Kc of the GaAs crystal,it also displays nonlinear behavior related to the applied load,which is caused by energy dissipation during the development process of cracks on the wafer.
基金National Natural Science Foundation of China(61605116,51972213)Science and Technology Commission of Shanghai Municipality(15ZR1440600,15520503400)。
文摘Rare-earth doped inorganic ferroelectrics are considered as novel photochromic materials,with potential applications for optical switch and information storage(K0.5Na0.5)1–xEuxNbO3(KNN:xEu)ceramics were prepared by high temperature calcination,with precursor powder obtained by hydrothermal method.Strong red emission at 615 nm was observed which corresponds to the 5D0→7F2 transition of Eu3+under excitation of 465 nm.Under UV light irradiation for 3 min,the color of the ceramics turned from milky white to dark gray.The colored samples returned to the original color when heated at 200℃for 10 min,showing strong photochromic behavior.Meanwhile,the luminescence intensity of Eu3+can be tuned without obvious degradation by alternating UV light and heat stimulus.Upon UV light irradiation,large luminescence modulation ratio(ΔRt)up to 83.9%was achieved for KNN:0.06Eu,indicating good luminescence switching behavior.A possible mechanism for non-radiative energy transfer from the luminescent center to the color center was proposed according to their luminescent behavior.
基金Supported by the National Natural Science Foundation of China(No.72104155)Postdoctoral Research Project,West China Hospital,Sichuan University(No.2020HXBH148)the 1•3•5 Project for Disciplines of Excellence,West China Hospital,Sichuan University(No.ZYYC08003)。
文摘Objective To assess whether the use of Tanreqing(TRQ)Injection could show improvements in time to extubation,intensive care unit(ICU)mortality,ventilator-associated events(VAEs)and infection-related ventilator associated complication(IVAC)among patients receiving mechanical ventilation(MV).Methods A time-dependent cox-regression analysis was conducted using data from a well-established registry of healthcare-associated infections at ICUs in China.Patients receiving continuous MV for 3 days or more were included.A time-varying exposure definition was used for TRQ Injection,which were recorded on daily basis.The outcomes included time to extubation,ICU mortality,VAEs and IVAC.Time-dependent Cox models were used to compare the clinical outcomes between TRQ Injection and non-use,after controlling for the influence of comorbidities/conditions and other medications with both fixed and time-varying covariates.For the analyses of time to extubation and ICU mortality,Fine-Gray competing risk models were also used to measure competing risks and outcomes of interest.Results Overall,7,685 patients were included for the analyses of MV duration,and 7,273 patients for the analysis of ICU mortality.Compared to non-use,patients with TRQ Injection had a lower risk of ICU mortality(Hazards ratios(HR)0.761,95%CI,0.581–0.997),and was associated with a higher hazard for time to extubation(HR 1.105,95%CI,1.005–1.216),suggesting a beneficial effect on shortened time to extubation.No significant differences were observed between TRQ Injection and non-use regarding VAEs(HR 1.057,95%CI,0.912–1.225)and IVAC(HR 1.177,95%CI,0.929–1.491).The effect estimates were robust when using alternative statistic models,applying alternative inclusion and exclusion criteria,and handling missing data by alternative approaches.Conclusion Our findings suggested that the use of TRQ Injection might lower mortality and improve time to extubation among patients receiving MV,even after controlling for the factor that the use of TRQ changed over time.