Metalens in Improving Imaging Quality: Advancements,Challenges, and Prospects for Future Display

Metalens, a metasurface with a focusing phase, has been the focus of research due to its immense potential for use in imaging and display technology. Traditional lens and optical imaging systems rely on phase accumulation, however metalens with subwavelength structures provide a disruptive path for miniaturized optical imaging systems by allowing unfettered modulation of incident light's phase and amplitude. Recently, extensive efforts have been devoted to exploring new design strategies, new functionalities, and possible applications. This paper reviews the development, principle, classification, and research status of metalens. In particular, this review focuses on the progress and challenges of improving imaging quality and expanding imaging diversity, including improvements of resolution, enhancement of depth of field, extension of field of view, and achromatism. Lastly, the prospects of metalens in the future display are summarized, and the application potentials of metalens in novel 3D display, intelligent and bionic display, as well as nano-pixelate light-emitting display (NLED) are emphasized.     

3维并行全电磁粒子模拟软件UNIPIC-3D

介绍了自行研制的3维并行全电磁粒子模拟软件UNIPIC-3D。在该软件中,电磁场量用二阶精度的时域有限差分方法迭代,粒子用相对论牛顿-洛仑兹力方程推进。该软件拥有复杂器件的几何建模和网格自动剖分的功能,具有模拟相对论返波管、虚阴极振荡器、磁绝缘线振荡器等高功率微波器件的能力。且该软件具有强大的后处理功能,可以显示电场、磁场、电流、电压、功率、频谱、粒子相空间等。在高性能并行计算机上对软件的并行效率进行了测试。通过与2.5维UNIPIC软件的结果进行比较,验证了UNIPIC-3D软件的正确性。     

真空磁绝缘传输线损失电子模拟

 真空磁绝缘传输线建立磁绝缘状态的初始阶段,损失电子轰击阳极,发生轫致辐射。针对自限制流同轴圆筒模型,通过粒子模拟获得了损失前沿在能量传输方向的推进速度、电子到达阳极时的能谱和角分布情况,在此基础上采用蒙特卡罗方法模拟得到了轫致辐射所产生的X射线能谱。数值计算结果表明:电磁波损失前沿在能量传输方向的推进速度小于光速;损失前沿电子密度稳定。在自限制流磁绝缘传输线中,损失电子处在较宽的能量范围内,其电子偏移角度较小。建立了对应于同轴圆筒真空磁绝缘传输线的电子/光子输运模型,获得了损失电子轰击阳极产生的X射线能谱。     

Synthesis of Cd-free water-soluble ZnSe(1-x)Te(x) nanocrystals with high luminescence in the blue region

Cd-free core-shell nanocrystals (ZnSe(1-x)Te(x)/ZnS, 0相似文献   

磁绝缘传输线损失电流等效电路模型

在粒子模拟的基础上,结合经典空间电荷限制流、磁绝缘临界电流的理论公式,拟合得到磁绝缘传输线中空间电荷限制流的修正计算公式,并进一步建立磁绝缘传输线损失电流的插值计算模型。该模型不需要求解广义泊松方程,计算效率高。通过对长同轴磁绝缘传输线的等效电路模拟,得到了与全尺寸粒子模拟结果基本一致的负载电压波形,插值计算模型不仅正确地反映了磁绝缘传输线中的电流损失过程,而且其等效电路模拟计算效率比粒子模拟提高3000倍以上。     

TDI CMOS图像传感器曝光时间优化方法研究

为了提高时间延迟积分互补金属氧化物半导体(TDI CMOS)图像传感器的成像质量,研究了TDI CMOS图像传感器中曝光时间的选取对成像质量的影响。基于行滚筒曝光读出原理,分别分析了曝光时间对信噪比(SNR)和调制传递函数(MTF)的影响机理,根据分析结果,提出在级数已选定的情况下,曝光时间的选取存在最优值,此时得到的图像质量较好。为验证结论,基于自主研发的TDI CMOS图像传感器芯片及现场可编程门阵列(FPGA)开发板,搭建了TDI CMOS图像传感器成像测试系统。实验中采用MTF×SNR作为评价图像质量的指标,实验结果表明,在选定的相机参数下,积分级数为8级,光强为20 lx时,TDI CMOS图像传感器曝光时间选取64 ms时所得到的图像质量最好,此时MTF×SNR最大。     

多相流局部混合型质点网格法

提出模拟多相流的局部混合型质点网格法,该方法能稳定地模拟高浓度流体颗粒两相 流. 在每一个颗粒团尺度的欧拉网格下(本文称之为欧拉微元),基于Lagrangian 追踪原理,可直接估计体积内颗粒的总量,从而准确求出欧拉微元和控制容积内颗粒的 浓度(即颗粒在容积内的体积含量). 同时,假设在新的时间步下,颗粒在欧拉微元里充分 混合,形成新颗粒团. 作者对竖直和倾斜容器中单粒径颗粒沉降和竖直容器中双粒径颗粒双 峰悬浮液沉降过程进行了计算,结果与实测数据相符.     

顺丁烯二酸酐均相配位催化氢化反应研究

研究了在室温和大气压力下，几种过渡金属络合物对顺丁烯二酸酐氢化生成琥珀酸酐的催化活性，实验结果表明，它们的催化活性顺序是：ＰｄＣｌ２（ＰｈＣＨ２ＣＮ）２〉ＲｕＣｌ２（ＰＰｈ３）３〉ＰｄＣｌ２（ＰｈＣＮ）２〉ＰｄＣｌ２（ＰＰｈ３）２＝ＲｈＣｌ（ＰＰｈ３）２，在所应用的反应条件下，其中催化活性最高的络合物，ＰｄＣｌ２（ＰｈＣＨ２ＣＮ）２，给出了琥珀酸酐的产率高达９３．０％。     

数字化机步旅抢修任务动态调度框架研究

针对一体化机动进攻作战中战场抢修任务动态分配缺乏定量化确定方法的问题,对数字化机步旅抢修任务动态调度的框架结构进行了研究。借鉴Hall三维结构方法论,从对象维、过程维和技术维3个维度建立了抢修任务动态调度的框架结构,并以此为基础,分析梳理出了抢修任务动态调度的7个核心子问题,总结了这些核心子问题的自身特性,为抢修任务动态调度的后续研究提供了宏观规划和微观指导。     

Blue native/SDS‐PAGE combined with iTRAQ analysis reveals advanced glycation end‐product‐induced changes of synaptosome proteins in C57 BL/6 mice

Evidence shows that administration of high‐level D ‐galactose induces the production of advanced glycation end‐products (AGEs) that have been implicated in the development of diabetic complications such as neuropathy. The deterioration of learning and memory during neuropathy might be associated with the altered expression of proteins in synapse. To evaluate AGE‐induced protein network alterations in synapse, blue native/SDS‐PAGE and iTRAQ proteomic methods were used to screen for differentially expressed synaptic proteins of cerebral cortex in D ‐galactose‐induced C57 BL/6 mice. In total, the expression level of 84 proteins is changed during AGE accumulation. The significantly differentially expressed proteins mainly participate in neurotransmission, energy metabolism and signal transduction pathway, suggesting that energy metabolism is damaged and neurotransmission is attenuated in synapse. The results of in vivo activities of malondialdehyde and superoxide dismutase suggested that AGE accumulation in the brain leads to the generation of reactive oxygen species. Therefore, elucidating the differentially expressed proteins underlying the AGE accumulation will open a new window to the mechanism of learning and memory impairments in neuropathy.