Ferroelectric ceramics have the potential to be widely applied in the modern industry and military power systems due to their ultrafast charging/discharging speed and high energy density. Considering the structural design and electrical properties of ferroelectric capacitor, it is still a challenge to find out the optimal energy storage of ferroelectric ceramics during the phase-transition process of amorphous/nanocrystalline and polycrystalline. In this work, a finite element model suitable for the multiphase ceramic system is constructed based on the phase field breakdown theory. The nonlinear coupling relationship of multiple physical fields between multiphase ceramics was taken into account in this model. The basic structures of multiphase ceramics are generated by using the Voronoi diagram construction method. The specified structure of multiphase ceramics in the phase-transition process of amorphous/nanocrystalline and polycrystalline was further obtained through the grain boundary diffusion equation. The simulation results show that the multiphase ceramics have an optimal energy storage in the process of amorphous polycrystalline transformation, and the energy storage density reaches the maximum when the crystallinity is 13.96% and the volume fraction of grain is 2.08%. It provides a research plan and idea for revealing the correlation between microstructure and breakdown characteristics of multiphase ceramics. This simulation model realizes the nonlinear coupling of the multiphase ceramic mesoscopic structure and the phase field breakdown. It provides a reference scheme for the structural design and performance optimization of ferroelectric ceramics.

该文介绍了一种基于空腔结构的温度补偿型薄膜体声波谐振器(TC-FBAR)。通过在压电层上方生长SiO2温度补偿层，实现谐振器的低温漂。未采用温度补偿的薄膜体声波谐振器，其频率温度系数约为-25×10-6/℃。通过适当的膜层结构设计，可使其频率温度系数在±3×10-6/℃。结果表明，由于温度补偿层的增加，导致器件总体压电效应降低，使谐振器的有效机电耦合系数降低。低温漂谐振器的实现，为窄带低温漂滤波器的研制提供了有效的设计和工艺技术支撑。

针对大规模多输入多输出(MIMO)系统中线性最小均方误差(MMSE)信号检测算法复杂的高维矩阵求逆难以用于实际工程的问题,文章基于矩阵分块思想并结合Neumann级数展开算法,提出了一种低复杂度的混合迭代算法。利用MMSE算法中加权矩阵逆矩阵的Neumann级数二阶展开作为其分块矩阵求逆的迭代初始值,可以有效提高算法收敛速度。仿真结果表明,该方法能以较少迭代次数逼近传统MMSE算法较优检测性能,并降低计算复杂度。

该文介绍了一种单端口、端口阻抗50 Ω的S波段薄膜体声波谐振器(FBAR)陷波器, 其采用了梯形拓扑结构与外围匹配电路相结合的方式。对FBAR陷波器芯片的设计过程、工艺实现进行了说明。测试制备的FBAR陷波器,其陷波频段为2 399~2 412 MHz, 陷波抑制达35 dBc; 通带频率分别为1 800~2 300 MHz和2 500~2 800 MHz, 通带插损仅1 dB; 3 dBc开口宽度为69 MHz。FBAR陷波器芯片尺寸为1.2 mm×1.2 mm×0.35 mm。结果表明, 陷波器实测与仿真结果两者相吻合。

采用高温固相法制备了Sr3LiSbO6∶Eu3+(SLSO∶Eu3+)红色荧光粉。系统研究了Eu3+ 浓度对发光强度的影响, 并对样品进行了XRD、荧光光谱（PL）、荧光寿命、热稳定性和色坐标分析。结果表明, 制备的荧光粉Sr3LiSbO6∶Eu3+可被紫外光激发, 并在612 nm处表现出较强的红光发射带。研究了样品的浓度猝灭效应, 样品的最佳掺杂浓度为0.04%, 猝灭主要是因为偶极-偶极相互作用引起的。此外, 还探讨了样品的热稳定性, 在423 K时的发光强度为室温下的43.1%。最后对样品的荧光寿命和CIE进行了测试。以上结果表明制备的荧光粉Sr3LiSbO6∶Eu3+是一种新型LED红色荧光材料。

Functionalized black phosphorus (BP) nanosheets have been considered as promising nanoagents in cancer therapy due to their excellent photothermal conversion efficiency. However, it is still difficult to visually monitor the dynamic localization of BP nanoagents in cancer cells. In this paper, we systematically studied the second-harmonic generation (SHG) signals originating from exfoliated BP nanosheets. Interestingly, under the excitation of a high frequency pulsed laser at 950 nm, the SHG signals of BP nanosheets in vitro are almost undetectable because of their poor stability. However, the intracellular SHG signals from BP nanosheets could be measured by in vivo optical imaging due to the efficient enrichment of living HeLa cells. Moreover, the SHG signal intensity from BP nanosheets increases with the prolonged incubation time. It can be expected that the BP nanosheets could be a promising intracellular SHG nanoprobe employed for visually in vivo biomedical imaging in practical cancer photothermal therapy (PIT).

针对小型化双通带声表面波(SAW)滤波器的需求背景,对两端口、两通带的SAW滤波器的设计技术展开研究。通过搭建包含两组耦合模(COM)参数的双通带SAW滤波器声电协同仿真平台,分析优化滤波器性能,成功研制出CSP2520封装的双通带SAW滤波器, 其中心频率分别为1 995 MHz和2 185 MHz, 通带带宽均为40 MHz, 插入损耗小于3 dB, 通带间隔离度大于30 dB。测试与仿真结果基本一致。