A series of Ba5Si8O（21）：0.02Eu^2＋,0.09RE^3＋ persistent phosphors were synthesized by the solid-state reaction method.The measurement results of photoluminescence（PL）,phosphorescence and thermoluminescence（TL）...A series of Ba5Si8O（21）：0.02Eu^2＋,0.09RE^3＋ persistent phosphors were synthesized by the solid-state reaction method.The measurement results of photoluminescence（PL）,phosphorescence and thermoluminescence（TL）were analysed and discussed.The XRD results showed that samples codoped with different RE^3＋ were Ba5Si8O（21） single pure phase.Under the excitation,all samples exhibited a broad Eu^2＋ characteristic emission,and the La^3＋ co-doped sample emitted the brightest photoluminescence even though its persistent luminescence property was the worst because of the weakest electronegativity.However,Nd^3＋ electronegativity was suitable,thus after activation,the Ba5Si8O（21）：Eu^2＋,Nd^3＋ sample had the best persistent luminescence performance with the highest phosphorescence intensity and the persistent luminescence decay time beyond 8 h.The Nd^3＋ co-doped sample also had the largest thermoluminescence integral area which proved effectively it had longer persistent luminescence time.The luminescence mechanism was also proposed to study the photoluminescence and persistent luminescence process.These results showed that RE^3＋ electronegativities were distinctly important for persistent phosphors and choosing suitable electronegativity codopant was conducive to enhancing the phosphorescent performance.展开更多
Three novel dielectric ceramics Ba5LnZnNb9O30 (Ln= La, Nd and Sm) were synthesized and characterized in the BaO-Ln2O3-ZnO-Nb2O5 quaternary system, which formed the filled tungsten-bronze structures. The present cerami...Three novel dielectric ceramics Ba5LnZnNb9O30 (Ln= La, Nd and Sm) were synthesized and characterized in the BaO-Ln2O3-ZnO-Nb2O5 quaternary system, which formed the filled tungsten-bronze structures. The present ceramics exhibit high dielectric constant (εr) up to 310, low dielectric loss in the level of 10 3 at 1 MHz. Meanwhile, the temperature coefficients of the dielectric constant (τε) of Ba5LnZnNb9O3o varies from -1 390×10-6 to -1 220×10-6/℃as the radius of Ln3+ increases. The present ceramics are promising candidates for high dielectric constant and low loss dielectric ceramics.展开更多
The New Niobate Ba5NdTi3Nb7O30 was synthesized by solid state reaction at 1250℃ for 48h. The crystal structure and dielectric properties of Ba5NdTi3Nb7O30 were determined by X ray powder diffraction and dielectric me...The New Niobate Ba5NdTi3Nb7O30 was synthesized by solid state reaction at 1250℃ for 48h. The crystal structure and dielectric properties of Ba5NdTi3Nb7O30 were determined by X ray powder diffraction and dielectric measurements. The results show that Ba5NdTi3Nb7O30 belongs to ferroelectric phase of tetragonal tungsten bronze structure at room temperature with unit cell parameters: a=1.24424(4)nm, c=0.39476(2)nm, calculated density 5.719g·cm-3. Ba5NdTi3Nb7O30 belongs to relaxor ferroelectrics. The phase transition temperature (Tc) of Ba5NdTi3Nb7O30 from ferroelectric to paraelectric is found to shift toward higher temperature side at higher frequency, and Tc is 90℃ at 1kHz. At room temperature, the dielectric constant (εr) and dielectric loss of Ba5NdTi3Nb7O30 decrease with the increase of frequency, and Ba5NdTi3Nb7O30 ceramic have high dielectric constant 489 at 1kHz.展开更多
目的建立重组Omicron BA.4/5-Delta株新冠疫苗体外相对效力的检测方法,并进行验证,以期为替代体内效力检测奠定基础。方法以人源单克隆抗体GH4作为包被抗体,HRP标记的CB6人源单克隆抗体作为酶标抗体的双抗体夹心ELISA法为基础,确定疫苗...目的建立重组Omicron BA.4/5-Delta株新冠疫苗体外相对效力的检测方法,并进行验证,以期为替代体内效力检测奠定基础。方法以人源单克隆抗体GH4作为包被抗体,HRP标记的CB6人源单克隆抗体作为酶标抗体的双抗体夹心ELISA法为基础,确定疫苗解吸附方法;再以该解吸附方法结合双抗体夹心ELISA法建立体外相对效力检测方法。并验证方法的线性范围、专属性、准确性、精密性、耐用性及定量限。采用建立的方法检测3批供试品重组Omicron BA.4/5-Delta株新冠疫苗的体外相对效力。结果确定解吸附方法为:将疫苗与处理液(1.25 mL 20%二乙醇胺,0.20 mL 10%Triton X-100,8.55 mL PBS)按等体积分数混合,于25℃解离30 min,解吸附率可达95%以上。疫苗参考品在1~26 ng/mL浓度范围内,与A_(450)呈良好的线性关系,线性方程为log(y)=1.447 log(x)-1.643,R^(2)为0.998;可特异性检测疫苗参考品的体外相对效力;90000、50000和20000 ng/mL浓度疫苗参比品检测结果的回收率均在80%~120%范围内;重复性及中间精密性验证相对标准偏差(relative standard deviation,RSD)均<20%;解离条件、检测体系孵育时间和显色时间发生微小变动时,检测结果不受影响;定量限为0.2。批号为J202301002、J202301003、J202301004供试品的体外相对效力分别为1.0,1.0和0.8,RSD为11%。结论建立的用于检测体外相对效力的方法具有良好的准确性、精密性、专属性和耐用性,可用于重组Omicron BA.4/5-Delta株新冠疫苗体外相对效力的检测。展开更多
采用反应沉积外延法在723K的Si(111)衬底上共沉积了的Ba/Si混合膜,通过时间控制得到不同厚度的混合膜,然后真空退火处理。X射线衍射表明在真空中1073K退火12小时后出现了单一的Ba5Si3薄膜。采用第一性原理对Ba5Si3的能带结构进行了计算...采用反应沉积外延法在723K的Si(111)衬底上共沉积了的Ba/Si混合膜,通过时间控制得到不同厚度的混合膜,然后真空退火处理。X射线衍射表明在真空中1073K退火12小时后出现了单一的Ba5Si3薄膜。采用第一性原理对Ba5Si3的能带结构进行了计算,带隙宽度为0 e V,表现为金属性质。展开更多
基金Project supported by the National Natural Science Foundation of China(61265004,51272097)the Foundation of Application Research of Yunnan Province,China(2011FB022)
文摘A series of Ba5Si8O（21）：0.02Eu^2＋,0.09RE^3＋ persistent phosphors were synthesized by the solid-state reaction method.The measurement results of photoluminescence（PL）,phosphorescence and thermoluminescence（TL）were analysed and discussed.The XRD results showed that samples codoped with different RE^3＋ were Ba5Si8O（21） single pure phase.Under the excitation,all samples exhibited a broad Eu^2＋ characteristic emission,and the La^3＋ co-doped sample emitted the brightest photoluminescence even though its persistent luminescence property was the worst because of the weakest electronegativity.However,Nd^3＋ electronegativity was suitable,thus after activation,the Ba5Si8O（21）：Eu^2＋,Nd^3＋ sample had the best persistent luminescence performance with the highest phosphorescence intensity and the persistent luminescence decay time beyond 8 h.The Nd^3＋ co-doped sample also had the largest thermoluminescence integral area which proved effectively it had longer persistent luminescence time.The luminescence mechanism was also proposed to study the photoluminescence and persistent luminescence process.These results showed that RE^3＋ electronegativities were distinctly important for persistent phosphors and choosing suitable electronegativity codopant was conducive to enhancing the phosphorescent performance.
基金Projects(50572078 20571059) supported by the National Natural Science Foundation of China
文摘Three novel dielectric ceramics Ba5LnZnNb9O30 (Ln= La, Nd and Sm) were synthesized and characterized in the BaO-Ln2O3-ZnO-Nb2O5 quaternary system, which formed the filled tungsten-bronze structures. The present ceramics exhibit high dielectric constant (εr) up to 310, low dielectric loss in the level of 10 3 at 1 MHz. Meanwhile, the temperature coefficients of the dielectric constant (τε) of Ba5LnZnNb9O3o varies from -1 390×10-6 to -1 220×10-6/℃as the radius of Ln3+ increases. The present ceramics are promising candidates for high dielectric constant and low loss dielectric ceramics.
文摘The New Niobate Ba5NdTi3Nb7O30 was synthesized by solid state reaction at 1250℃ for 48h. The crystal structure and dielectric properties of Ba5NdTi3Nb7O30 were determined by X ray powder diffraction and dielectric measurements. The results show that Ba5NdTi3Nb7O30 belongs to ferroelectric phase of tetragonal tungsten bronze structure at room temperature with unit cell parameters: a=1.24424(4)nm, c=0.39476(2)nm, calculated density 5.719g·cm-3. Ba5NdTi3Nb7O30 belongs to relaxor ferroelectrics. The phase transition temperature (Tc) of Ba5NdTi3Nb7O30 from ferroelectric to paraelectric is found to shift toward higher temperature side at higher frequency, and Tc is 90℃ at 1kHz. At room temperature, the dielectric constant (εr) and dielectric loss of Ba5NdTi3Nb7O30 decrease with the increase of frequency, and Ba5NdTi3Nb7O30 ceramic have high dielectric constant 489 at 1kHz.
文摘目的建立重组Omicron BA.4/5-Delta株新冠疫苗体外相对效力的检测方法,并进行验证,以期为替代体内效力检测奠定基础。方法以人源单克隆抗体GH4作为包被抗体,HRP标记的CB6人源单克隆抗体作为酶标抗体的双抗体夹心ELISA法为基础,确定疫苗解吸附方法;再以该解吸附方法结合双抗体夹心ELISA法建立体外相对效力检测方法。并验证方法的线性范围、专属性、准确性、精密性、耐用性及定量限。采用建立的方法检测3批供试品重组Omicron BA.4/5-Delta株新冠疫苗的体外相对效力。结果确定解吸附方法为:将疫苗与处理液(1.25 mL 20%二乙醇胺,0.20 mL 10%Triton X-100,8.55 mL PBS)按等体积分数混合,于25℃解离30 min,解吸附率可达95%以上。疫苗参考品在1~26 ng/mL浓度范围内,与A_(450)呈良好的线性关系,线性方程为log(y)=1.447 log(x)-1.643,R^(2)为0.998;可特异性检测疫苗参考品的体外相对效力;90000、50000和20000 ng/mL浓度疫苗参比品检测结果的回收率均在80%~120%范围内;重复性及中间精密性验证相对标准偏差(relative standard deviation,RSD)均<20%;解离条件、检测体系孵育时间和显色时间发生微小变动时,检测结果不受影响;定量限为0.2。批号为J202301002、J202301003、J202301004供试品的体外相对效力分别为1.0,1.0和0.8,RSD为11%。结论建立的用于检测体外相对效力的方法具有良好的准确性、精密性、专属性和耐用性,可用于重组Omicron BA.4/5-Delta株新冠疫苗体外相对效力的检测。
