当前，超强超快激光正朝着全固态、高重复频率、新波段等方向发展，而发展新型激光材料是其关键基础之一。稀土掺杂碱土氟化物激光晶体兼具有晶体的高热导和玻璃的宽光谱特性，在全固态重复频率超强超快激光领域具有重要应用。本文简要概述了萤石型氟化物晶体稀土离子团簇结构的基本特征、稀土离子局域结构的演变规律，围绕稀土掺杂碱土氟化物激光晶体的结构设计、光谱调控及激光应用，综述了局域结构设计在探索新型宽光谱超快激光材料方面的最新研究进展，并对其发展趋势进行展望。

晶体材料的局部结构是对长程有序平均结构的偏离, 随着技术的进步和多年来的深入探究, 局部结构对材料性能的深刻影响逐渐被学界所认识, 对局部结构的探索为材料的性能提升和器件开发提供了关键理论指导。另一方面, 铁电材料往往具备十分复杂的局部结构, 并且局部结构对平均结构的偏离十分微小, 对其进行准确表征具有很大挑战性。本工作针对国际上较为通用的局部结构表征手段进行了综述, 主要包括基于X射线和中子进行的单晶漫散射实验技术和粉末全散射实验技术, 以及相关数据分析和结构模型构建方法; 此外, 对散射技术用于铁电压电材料局部结构表征的典型范例进行了回顾。

Automatic detection of a designated building area (DBA) is a research hotspot in the field of target detection using remote sensing images. Target detection is urgently needed for tasks such as illegal building monitoring, dynamic land use monitoring, antiterrorism efforts, and military reconnaissance. The existing detection methods generally have low efficiency and poor detection accuracy due to the large size and complexity of remote sensing scenes. To address the problems of the current detection methods, this paper presents a DBA detection method that uses hierarchical structural constraints in remote sensing images. Our method was conducted in two main stages. (1) During keypoint generation, we proposed a screening method based on structural pattern descriptors. The local pattern feature of the initial keypoints was described by a multilevel local pattern histogram (MLPH) feature; then, we used one-class support vector machine (OC-SVM) merely to screen those building attribute keypoints. (2) To match the screened keypoints, we proposed a reliable DBA detection method based on matching the local structural similarities of the screened keypoints. We achieved precise keypoint matching by calculating the similarities of the local skeletal structures in the neighboring areas around the roughly matched keypoints to achieve DBA detection. We tested the proposed method on building area sets of different types and at different time phases. The experimental results show that the proposed method is both highly accurate and computationally efficient.

Functional research on biological macromolecules must focus on specific local regions. PDBlocal is a web-based tool developed to overcome the limitations of traditional molecular visualization tools for three-dimensional (3D) inspection of local regions. PDBlocal provides an intuitive and easy-tomanipulate web page interface and some new useful functions. It can keep local regions flashing, display sequence text that is dynamically consistent with the 3D structure in local appearance under multiple local manipulations, use two scenes to help users inspect the same local region with different statuses, list all historical manipulation statuses with a tree structure, allow users to annotate regions of interest, and save all historical statuses and other data to a web server for future research. PDBlocal has met expectations and shown satisfactory performance for both expert and novice users. This tool is available at http://labsystem.scuec.edu.cn/pdblocal/.

为了提升红外与可见光图像融合精度,提出了一种基于局部区域奇异值分解的自适应PCNN红外与可见光图像融合算法.利用局部区域奇异值构造局部结构信息因子,作为PCNN对应神经元的链接强度.经过PCNN点火处理,获得源图像的点火映射图,通过比较选择算子,选择源图像中明显特征部分生成融合图像.采用多组红外与可见光图像进行融合实验,并对融合结果进行客观评价.实验结果表明本文提出的算法在主观和客观评价上均优于已有文献的一些典型融合算法,可获得更好的融合效果.

应用晶体场理论和不可约张量算符方法构造了3d2/3d8态离子在C3v对称晶场中包含自旋-轨道相互作用、自旋-自旋相互作用、自旋-其它轨道相互作用和其它轨道-其它轨道相互作用四种微观磁效应的45阶可完全对角化的能量哈密顿矩阵.利用该矩阵，计算了Ni2+∶α-Al2O3晶体的光谱精细结构和晶体局域结构，深入研究了Ni2+∶α-Al2O3晶体的自旋-轨道相互作用、自旋-自旋相互作用、自旋-其它轨道相互作用和其它轨道-其它轨道相互作用和它们对光谱精细结构的影响及Jahn-Teller效应.理论计算值和实验值相符合.研究发现，掺杂没有改变晶体的对称性、同时发现并合理解释了Ni2+对α-Al2O3晶体基态精细光谱中Jahn-Teller效应的存在机理.

应用晶体场理论和不可约张量算符方法构造了3d2/3d8态离子在C3v对称晶场中包含自旋-轨道相互作用、自旋-自旋相互作用、自旋-其它轨道相互作用和其它轨道-其它轨道相互作用四种微观磁效应的45阶可完全对角化的能量哈密顿矩阵.利用该矩阵，计算了V3+∶α-Al2O3和Ni2+∶α-Al2O3晶体的光谱精细结构、晶体局域结构和零场分裂参量，研究了掺入两种互补态离子Ni2+和V3+对同种晶体的光谱精细结构、晶体局域结构和零场分裂参量的影响，理论计算值和实验值相符.研究发现：掺杂没有改变晶体的光谱精细结构和能级分裂条数，但改变了能级间距；掺杂也没有改变晶体的对称性，但使晶体局域结构发生了一定程度的畸变； Ni2+∶α-Al2O3晶体局域结构的伸长畸变量大于V3+∶α-Al2O3晶体，键角的变化量小于V3+∶α-Al2O3晶体.

采用晶场参量的叠加模型，建立了结构参数与光谱之间的定量关系；利用完全对角化方法，由光谱确定Ni₂CdCl₆·12H₂O晶体中[Ni(H₂O)₆]²⁺络离子在温度为14K时的局域结构参数，较好地解释了Ni₂CdCl₆·12H₂O晶体中Ni²⁺离子的局域结构和光学吸收谱；研究结果发现，Ni₂CdCl₆·12H₂O晶体中络离子[Ni(H₂O)₆]²⁺的键长为R≈0．2009nm，键角为θ≈55．1°；所得光谱的理论结果与实验发现很好符合。