武汉理工大学材料科学与工程学院，武汉 430070
本文主要研究了CaO含量对CaOB2O3Al2O3SiO2(CBAS)玻璃/Al2O3低温共烧陶瓷结构和性能的影响。利用DSC、FTIR、XRD、SEM等测试方法对玻璃和低温共烧陶瓷的结构进行表征与分析。研究结果表明，CaO含量低于40%(质量分数，下同)时，由其引入的游离氧增加破坏了网络结构，降低玻璃黏度。CaO含量为40%及以上时，Ca2+与［SiO4］四面体形成较大的阴离子基团，增大玻璃黏度，提高玻璃化转变温度。CaO会促进CaSiO3和Ca2SiO4的析出和CaSiO3向Ca2SiO4的转变。CaO含量增加导致陶瓷的致密度先增加后减少，晶相尺寸增大，使陶瓷的密度、抗折强度和介电常数先增大后减小。当CaO含量为40%时，样品综合性能最好，密度最大为2.94 g/cm3,抗折强度为153.44 MPa,介电常数为9.69。
高CaO含量 CaOB2O3Al2O3SiO2玻璃 低温共烧陶瓷 晶相结构 烧结 high CaO content CaOB2O3Al2O3SiO2 glass low temperature cofired ceramic crystal structure sintering
Author Affiliations
Abstract
1 Center for Quantum Technology Research, School of Physics, Beijing Institute of Technology, Beijing 100081, China
2 Key Laboratory for Quantum Optics and Center for Cold Atom Physics of CAS, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
The performances of ghost imaging and conventional imaging in photon shot noise cases are investigated. We define an imaging signal-to-noise ratio called SNRtran where only the object’s transmission region is used to evaluate the imaging quality and it can be applied to ghost imaging (GI) with any random pattern. Both the values of GI and of conventional imaging in photon shot noise cases are deduced from a simple statistical analysis. The analytical results, which are backed up by numerical simulations, demonstrate that the value is related to the ratio between the object’s transmission area Ao and the number density of photons illuminating the object plane Io, which is similar to the theoretical results based on the first principle of GI with a Gaussian speckle field deduced by B. I. Erkmen and J. H. Shapiro [in Adv. Opt. Photonics 2, 405–450 (2010)]. In addition, we also show that the value will be larger than when Ao is beyond a threshold value.
ghost imaging photon shot noise signal-to-noise ratio speckle Chinese Optics Letters
2020, 18(7): 071101
