Molecular Configuration Engineering in Hole-Transporting Materials toward Efficient and Stable Perovskite Solar Cells

The development of hole-transporting materials (HTMs) that can passivate defects in perovskite is of great significance in improving the efficiency and long-term stability of perovskite solar cells. To date, the investigation on HTMs mainly focus on exploring new structures, while molecular configuration is seldomly concerned. In this work, two small molecules are developed as HTMs with benzil and phenanthrene quinone as the core structure, respectively. With similar structure and the same defect passivation groups, whereas, the two molecules exhibit different configurations, thus distinct properties. Compared to 3,6-bis(3,6-bis(bis(4-methoxyphenyl)amino)-9H-carbazol-9-yl)phenanthrene-9,10-dione (PQ) with a rigid core structure, the benzil group in 1,2-bis(4-(3,6-bis(bis(4-methoxyphenyl)amino)-9H-carbazol-9-yl)phenyl)ethane-1,2-dione (DB) is flexible and can adjust molecular configuration to efficiently interact with the underlying perovskite material, which is confirmed from both experimental results and theoretical simulations. The DB-based device exhibits a high power conversion efficiency of 22.21% with excellent long-term stability, superior to the PQ-based device (20.22%). This study demonstrates that molecular configuration engineering will directly affect the properties of hole transport materials, as well as their interactions with perovskite, which should also be taken into consideration when devising HTMs.     

考虑宏观政策的能源需求组合预测模型

针对目前能源需求预测考虑影响因素单一、忽视宏观政策影响因素、预测精度不足等问题,提出了一种融合灰色关联度分析和BP神经网络的能源需求组合预测方法.首先,根据宏观政策的针对性和方向性进行领域划分,分析各领域的指标;其次,利用灰色关联度分析法对分析后的各领域宏观政策初始指标进行关联度计算、排序、筛选;最后,将筛选出的初始指...     

Range-gated laser image compression and encryption scheme based on bidirectional diffusion

The existing image encryption schemes are not suitable for the secure transmission of large amounts of data in range-gated laser imaging under high noise background. Aiming at this problem, a range-gated laser imaging image compression and encryption method based on bidirectional diffusion is proposed. The image data collected from the range-gated laser imaging source is sparsely represented by the discrete wavelet transform. Arnold chaotic system is used to scramble the sparse matrix, and then the measurement matrix is constructed by the quantum cellular neural network (QCNN) to compress the image. In addition, the random sequence generated by QCNN hyperchaotic system is used to carry out "bidirectional diffusion" operation on the compression result, so as to realize the security encryption of image data. The comparative analysis of the security encryption performance of different compression ratios shows that the histogram sample standard of the encrypted image can reach about 10, and the information entropy value is more than 7.99, which indicates that the encryption scheme effectively hides the plaintext information of the original image. When the encrypted image is attacked by different degrees of noise, this method can still reconstruct the image through the effective decryption process. The experimental results show that this method realizes the secure compression and encryption of gated-laser imaging image data, and effectively ensures the security of data while reducing the amount of channel transmission data.     

高海拔区特征环境驱动下混凝土坝服役性能研究进展

以青藏高原为代表的高海拔地区汇聚着中国一半以上的待开发水能资源，在国家推动实现碳达峰与碳中和目标的重大战略背景下，相关地区水利水电工程的劣化状态、运行性态、灾变模态日益受到关注。在系统梳理高海拔地区典型环境基础上，从研究方法、影响规律、主控致因、防控措施等方面介绍了低大气压力、强太阳辐射、低温、低湿度、大温度日较差等高海拔地区自然环境特征对混凝土坝服役性能影响的主要研究进展。针对现有研究在高海拔区混凝土坝工程健康诊断与灾变风险防控方面的不足，从复合特征环境工况下的大坝性态馈控、混凝土多尺度劣化规律、材料与结构长期性能演化、工程组合系统行为分析等视角给出了进一步探讨的命题。     

Dummy trajectory generation scheme based on generative adversarial networks

Neural Computing and Applications - Dummy trajectory is widely used to protect the privacy of mobile users’ locations. However, two main challenges remain: (1) Map background information has...     

环氧烷烃与硫代内酯交替共聚制备聚酯硫醚及性能探究

采用金属铬配合物/双-(三苯基正膦基)氯化铵/叔丁醇锂组成的三组分催化体系,实现了多种环氧烷烃与γ-硫代丁内酯(TBL)高活性开环共聚。发现聚合过程中叔丁醇锂可以有效稳定链末端硫负离子,抑制其回咬,保证了反应的活性以及聚合物的分子量。采用₁^H NMR、₁₃^C NMR、ESI-MS以及FTIR对聚合物结构进行了表征,通过DSC和TGA考察了不同结构聚酯硫醚的热性能。结果表明,聚酯硫醚均具有完全交替结构且呈现无定形态,玻璃化转变温度(T_g)处于?53~?18 °C之间,5%热失重温度在258~300 °C之间。通过氧化反应进一步获得含亚砜和砜结构单元的含硫聚合物,使得T_g大大提高。以叔丁基缩水甘油醚与TBL的共聚物为例,其硫醚结构被氧化为亚砜和砜结构后聚合物T_g分别提高了49和60 °C。     

Uniting Dual-Modal MRI/Chemiluminescence Nanotheranostics: Spatially and Sensitively Self-Reporting Photodynamic Therapy in Oral Cancer

Unpredictable in vivo therapeutic feedback of reactive oxygen species (ROS) efficiency is the major bottleneck of photodynamic therapy (PDT). Herein, novel PDT-based nanotheranostics Pa–Mn&CH-A@P are elaborately constructed for in vivo tracking biodistribution and in situ self-reporting PDT, which innovatively unites magnetic resonance imaging (MRI) and chemiluminescence (CL) signals. Taking advantages of the versatility of lanthanide coordination chemistry and flash nanoprecipitation (FNP) technology, photosensitizers, MRI, and CL agents are unprecedently integrated within a stable and uniform nanotheranostic. Specifically, MRI signal offers detailed dose distribution of nanotheranostics with high-spatial resolution, and CL signal timely performs in situ evaluation of ROS generation with high sensitivity. This dual-modal MRI/CL nanotheranostic makes a breakthrough in high fidelity feedback for oral tumor, conquering the inherent unpredictable obstacles on spatially and sensitively reporting PDT.