The finding of the robust ferroelectricity in HfO₂-based thin films is fantastic from the view point of both the fundamentals and the applications. In this review article, the current research status of the future prospects for the ferroelectric HfO₂-based thin films and devices are presented from fundamentals to applications. The related issues are discussed, which include: 1) The ferroelectric characteristics observed in HfO₂-based films and devices associated with the factors of dopant, strain, interface, thickness, defect, fabrication condition, and more; 2) physical understanding on the observed ferroelectric behaviors by the density functional theory (DFT)-based theory calculations; 3) the characterizations of microscopic and macroscopic features by transmission electron microscopes-based and electrical properties-based techniques; 4) modeling and simulations, 5) the performance optimizations, and 6) the applications of some ferroelectric-based devices such as ferroelectric random access memory, ferroelectric-based field effect transistors, and the ferroelectric tunnel junction for the novel information processing systems.

设计一种电磁加载系统应用于分离式霍普金森杆实验装置，能够克服传统气压驱动的缺点，达到精确控制入射应力波的目的。通过对电磁加载技术的调研，了解不同加载方式的电压等级，确定低压加载方式；构建系统等效RLC回路，推导回路参数与入射应力波的函数关系。结合理论计算，利用有限元软件进行耦合场仿真，仿真发现放电线圈匝数对入射应力波的幅频特性影响较大，同时为了保证电磁能量的利用效率，需要保证感应线圈的厚度大于磁渗透深度，最后根据实验要求确定电磁加载系统各参数。按照加载系统参数搭建实验平台，进行霍普金森杆冲击实验，通过对入射应力波的测量，验证了理论计算及软件仿真的正确性。

针对目前透明度遥感反演研究多以较低空间分辨率卫星数据为主的现状，采用分辨率高达10 m的Sentinel-2卫星数据进行了胶州湾海域水体透明度的遥感反演研究。构建了基于实测数据的反演模型。结果表明：模型具有较高的精度，反演值与实测值的平均相对误差为9.86%，均方根误差为0.22 m。依据构建的反演模型与卫星影像数据反演了胶州湾水体的透明度，绘制了水体的透明度分布图，分析了胶州湾海域水体透明度的空间分布规律和局部的细微变化特征。研究发现，胶州湾海域水体透明度呈现由近岸向外海逐渐升高的趋势，径流量大的河流会造成汇入海域透明度明显降低的变化，潮汐会引起透明度出现沿垂直于岸边方向的纹理变化特征，大型船只的通航会造成透明度短时降低的变化。

Plasmonic nanolaser as a new type of ultra-small laser, has gain wide interests due to its breaking diffraction limit of light and fast carrier dynamics characters. Normally, the main problem that need to be solved for plasmonic nanolaser is high loss induced by optical and ohmic losses, which leads to the low quality factor. In this work, InGaN/GaN nanoplate plasmonic nanolaser with large interface area were designed and fabricated, where the overlap between SPs and excitons can be enhanced. The lasing threshold is calculated to be ~6.36 kW/cm², where the full width at half maximum (FWHM) drops from 27 to 4 nm. And the fast decay time at 502 nm (sharp peak of stimulated lasing) is estimated to be 0.42 ns. Enhanced lasing characters are mainly attributed to the strong confinement of electromagnetic wave in the low refractive index material, which improve the near field coupling between SPs and excitons. Such plasmonic laser should be useful in data storage applications, biological application, light communication, especially for optoelectronic devices integrated into a system on a chip.

In this work, a blue gallium nitride (GaN) micro-light-emitting-diode (micro-LED)-based underwater wireless optical communication (UWOC) system was built, and UWOCs with varied Maalox, chlorophyll, and sea salt concentrations were studied. Data transmission performance of the UWOC and the influence of light attenuation were investigated systematically. Maximum data transmission rates at the distance of 2.3 m were 933, 800, 910, and 790 Mbps for experimental conditions with no impurity, 200.48 mg/m³ Maalox, 12.07 mg/m³ chlorophyll, and 5 kg/m³ sea salt, respectively, much higher than previously reported systems with commercial LEDs. It was found that increasing chlorophyll, Maalox, and sea salt concentrations in water resulted in an increase of light attenuation, which led to the performance degradation of the UWOC. Further analysis suggests two light attenuation mechanisms, e.g., absorption by chlorophyll and scattering by Maalox, are responsible for the decrease of maximum data rates and the increase of bit error rates. Based on the absorption and scattering models, excellent fitting to the experimental attenuation coefficient can be achieved, and light attenuation by absorption and scattering at different wavelengths was also investigated. We believe this work is instructive apply UWOC for practical applications.