MAX/MAB相是一类非范德华三元层状材料, 具有丰富的元素组成和晶体结构, 兼具陶瓷和金属的物理性质, 在高温、强腐蚀、辐照等极端环境中极具应用潜力。近年来, 由MAX/MAB相衍生的二维(2D)材料(MXene和MBene)在材料物理与材料化学领域引起了广泛兴趣, 已经成为继石墨烯和过渡金属硫族化合物之后最受关注的二维范德华材料。MAX/MAB相材料结构调控不仅对这类非范德华层状材料本征性能产生重要影响, 而且对其衍生的二维范德华材料结构功能特性研究也具有重要价值。本文归纳和总结了MAX/MAB相层状材料在结构调控、理论计算和应用基础研究等方向的最新科研进展, 并展望了该类层状材料未来发展方向。

光学信息处理技术本身具有高速度、并行性、信息容量大的特点。同时，光波又具有振幅、相位、波长、偏振等多种属性，是多维信息的载体。因此，光学加密在信息安全传输领域意义重大。现有的图像加密方法存在效率低、安全性差、加密容量小等问题。为了实现多图像二次加密传输，提出了一种基于级联相位迭代与计算关联成像的多图像加密算法。该方法可以同时对多幅图像进行高效加密，计算简单，安全可靠，传输数据少。利用相关系数指标评估了该方法的加密效果，并通过仿真实验验证了该方法的有效性和安全性。

提出面向合成孔径雷达（Synthetic Aperture Radar，SAR）回波数据的复杂结构特征增强算法（Complex Structure Feature Enhancement Algorithm，CEA），面向SAR成像目标的复杂结构特征，算法利用高阶方向全变分（High-order Total Direction Variation，HOTDV）正则算子表示，面向SAR成像目标的稀疏特征，算法用𝓁1正则算子表示。算法利用交替方向多乘子法（Alternating Direction Method of Multipliers，ADMM）建立多正则约束优化框架，设计复杂结构分裂变量和稀疏分裂变量，并求出分裂变量解析更新解以实现SAR成像目标的复杂结构特征与稀疏特征的增强。多正则约束优化框架中的对偶分解保证多特征多任务处理能力，增广拉格朗日项的使用则保证了算法的收敛性和稳健性。最后，设计了仿真和实测SAR数据特征增强实验以验证算法的有效性，对比多种传统结构特征增强算法以验证所提复杂结构特征增强算法的优越性。

Transport of intensity equation (TIE) is a well-established non-interferometric phase retrieval approach that enables quantitative phase imaging (QPI) by simply measuring intensity images at multiple axially displaced planes. The advantage of a TIE-based QPI system is its compatibility with partially coherent illumination, which provides speckle-free imaging with resolution beyond the coherent diffraction limit. However, TIE is generally implemented with a brightfield (BF) configuration, and the maximum achievable imaging resolution is still limited to the incoherent diffraction limit (twice the coherent diffraction limit). It is desirable that TIE-related approaches can surpass this limit and achieve high-throughput [high-resolution and wide field of view (FOV)] QPI. We propose a hybrid BF and darkfield transport of intensity (HBDTI) approach for high-throughput quantitative phase microscopy. Two through-focus intensity stacks corresponding to BF and darkfield illuminations are acquired through a low-numerical-aperture (NA) objective lens. The high-resolution and large-FOV complex amplitude (both quantitative absorption and phase distributions) can then be synthesized based on an iterative phase retrieval algorithm taking the coherence model decomposition into account. The effectiveness of the proposed method is experimentally verified by the retrieval of the USAF resolution target and different types of biological cells. The experimental results demonstrate that the half-width imaging resolution can be improved from 1230 nm to 488 nm with 2.5 × expansion across a 4 × FOV of 7.19 mm², corresponding to a 6.25 × increase in space-bandwidth product from ∼5 to ∼30.2 megapixels. In contrast to conventional TIE-based QPI methods where only BF illumination is used, the synthetic aperture process of HBDTI further incorporates darkfield illuminations to expand the accessible object frequency, thereby significantly extending the maximum available resolution from 2NA to ∼5NA with a ∼5 × promotion of the coherent diffraction limit. Given its capability for high-throughput QPI, the proposed HBDTI approach is expected to be adopted in biomedical fields, such as personalized genomics and cancer diagnostics.

A Hardy-like proof of quantum contextuality is a compelling way to see the conflict between quantum theory and noncontextual hidden variables (NCHVs), as the latter predict that a particular probability must be zero, while quantum theory predicts a nonzero value. For the existing Hardy-like proofs, the success probability tends to 1/2 when the number of measurement settings n goes to infinity. It means the conflict between the existing Hardy-like proof and NCHV theory is weak, which is not conducive to experimental observation. Here we advance the study of a stronger Hardy-like proof of quantum contextuality, whose success probability is always higher than the previous ones generated from a certain n-cycle graph. Furthermore, the success probability tends to 1 when n goes to infinity. We perform the experimental test of the Hardy-like proof in the simplest case of n=7 by using a four-dimensional quantum system encoded in the polarization and orbital angular momentum of single photons. The experimental result agrees with the theoretical prediction within experimental errors. In addition, by starting from our Hardy-like proof, one can establish the stronger noncontextuality inequality, for which the quantum-classical ratio is higher with the same n, which provides a new method to construct some optimal noncontextuality inequalities. Our results offer a way for optimizing and enriching exclusivity graphs, helping to explore more abundant quantum properties.

研究钙钛矿晶体缺陷对于推动钙钛矿太阳能电池的发展至关重要。缺陷不仅会引起大量非辐射复合, 而且会造成器件稳定性下降。为降低材料缺陷对光伏性能的影响, 有必要深入了解钙钛矿薄膜缺陷的种类及抑制方法。根据电子特性, 缺陷可分为富电子缺陷和缺电子缺陷。利用Lewis酸碱理论, 富电子缺陷可以被Lewis酸钝化, 而缺电子缺陷可以被Lewis碱或离子液体钝化。这些钝化功能添加剂可在钙钛矿成膜过程中加入, 或对薄膜表面进行后处理。本文通过总结近年报道的缺陷钝化案例, 直观地呈现了添加剂的设计策略及缺陷钝化对光伏性能的影响,最后, 提出开发多功能钝化剂、大面积钝化策略与先进电荷传输层的建议, 期望为钙钛矿太阳能电池的发展提供助力。