Rational Design of a Near-infrared Fluorescent Material with High Solid-state Efficiency,Aggregation-induced Emission and Live Cell Imaging Property

Near-infrared(NIR) fluorescent materials with high photoluminescent quantum yields(PLQYs) have wide application prospects. Therefore, we design and synthesize a D-A type NIR organic molecule, TPATHCNE, in which triphenylamine and thiophene are utilized as the donors and fumaronitrile is applied as the acceptor. We systematically investigate its molecular structure and photophysical property. TPATHCNE shows high T_gof 110℃ and T_d of 385℃ and displays an aggregation-induced emission(AIE) property. A narrow optical bandgap of 1.65 eV is obtained. The non-doped film of TPATHCNE exhibits a high PLQY of 40.3% with an emission peak at 732 nm, which is among the best values of NIR emitters. When TPATHCNE is applied in organic light-emitting diode(OLED), the electroluminescent peak is located at 716 nm with a maximum external quantum efficiency of 0.83%. With the potential in cell imaging, the polystyrene maleic anhydride(PMSA) modified TPATHCNE nanoparticles(NPs) emit strong fluorescence when labeling HeLa cancer cells, suggesting that TPATHCNE can be used as a fluorescent carrier for specific staining or drug delivery for cellular imaging. TPATHCNE NPs fabricated by bovine serum protein(BSA) are cultivated with mononuclear yeast cells, and the intense intracellular red fluorescence indicates that it can be adopted as a specific stain for imaging.     

Developing Flexible Quinacridone-Derivatives-Based Photothermal Evaporaters for Solar Steam and Thermoelectric Power Generation

Solar-driven interfacial vaporization by localizing solar-thermal energy conversion to the air−water interface has attracted tremendous attention. In the process of converting solar energy into heat energy, photothermal materials play an essential role. Herein, a flexible solar-thermal material di-cyan substituted 5,12-dibutylquinacridone (DCN−4CQA)@Paper was developed by coating photothermal quinacridone derivatives on the cellulose paper. The DCN−4CQA@Paper combines desired chemical and physical properties, broadband light-absorbing, and shape-conforming abilities that render efficient photothermic vaporization. Notably, synergetic coupling of solar-steam and solar-electricity technologies by integrating DCN−4CQA@Paper and the thermoelectric devices is realized without trade-offs, highlighting the practical consideration toward more impactful solar heat exploitation. Such solar distillation and low-grade heat-to-electricity generation functions can provide potential opportunities for fresh water and electricity supply in off-grid or remote areas.     

Reverse Thinking of the Aggregation-Induced Emission Principle: Amplifying Molecular Motions to Boost Photothermal Efficiency of Nanofibers**

Using reverse thinking of the aggregation-induced emission (AIE) principle, we demonstrate an ingenious and universal protocol for amplifying molecular motions to boost photothermal efficiency of fibers. Core–shell nanofibers having the olive oil solution of AIE-active molecules as the core surrounded by PVDF-HFP shell were constructed by coaxial electrospinning. The molecularly dissolved state of AIE-active molecules allows them to freely rotate and/or vibrate in nanofibers upon photoexcitation and thus significantly elevates the proportion of non-radiative energy dissipation, affording impressive heat-generating efficiency. Photothermal evaluation shows that the core–shell nanofibers with excellent durability can reach up to 22.36 % of photothermal conversion efficiency, which is 26-fold as the non-core–shell counterpart. Such a core–shell fiber can be used for photothermal textiles and solar steam generation induced by natural sunlight with green and carbon-zero emission.     

CiADS束流负载效应前馈补偿的仿真评估

在高功率超导质子直线加速器中，束流负载效应是影响超导腔幅相稳定性的一个重要因素。本工作基于谐振腔建场模型，开发了超导腔系统束流负载效应的时域仿真程序，分析了束流负载效应对超导腔幅相稳定性的影响，并在C-ADS注入器II上通过相关实验测量对仿真结果进行了验证。利用该程序，评估了CiADS超导直线加速器脉冲束流的脉冲长度，以及前馈补偿的时序抖动和束流纹波等因素对腔中电磁场幅相稳定度的影响。仿真结果表明:在当前CiADS直线加速器设计参数下，为满足超导腔中电磁场0.1%与在高功率超导质子直线加速器中，束流负载效应是影响超导腔幅相稳定性的一个重要因素。本工作基于谐振腔建场模型，开发了超导腔系统束流负载效应的时域仿真程序，分析了束流负载效应对超导腔幅相稳定性的影响，并在C-ADS注入器II上通过相关实验测量对仿真结果进行了验证。利用该程序，评估了CiADS超导直线加速器脉冲束流的脉冲长度，以及前馈补偿的时序抖动和束流纹波等因素对腔中电磁场幅相稳定度的影响。仿真结果表明:在当前CiADS直线加速器设计参数下，为满足超导腔中电磁场0.1%与$0.1^{\circ}$的幅相稳定度指标，前馈时序抖动的偏差不能超过0.79 μs，束流流强的直流偏差不能超过0.9%，并且给出了束流纹波的最大抖动幅值与纹波频率之间的关系。这些结果将为CiADS超导直线加速器相关子系统技术指标的确定提供依据。     

Persistence properties and wave‐breaking criteria for the Geng‐Xue system

Considered herein is a two‐component Novikov equations (called Geng‐Xue system for short) with cubic nonlinearities. The persistence properties and some unique continuation properties of the solutions to the system in weighted L_p spaces are established. Moreover, a wave‐breaking criterion for strong solutions is determined in the lowest Sobolev space by using the localization analysis in the transport equation theory, and we also give a lower bound for the maximal existence time.     

Ultra-high Tg and ultra-low coefficient of thermal expansion polyimide films based on hydrogen bond interaction

To tolerate high processing temperature during the fabrication of low-temperature polycrystalline silicon thin-film transistors (LTPS–TFT) in flexible OLED devices, the polyimide (PI) films, which are used as substrate, should have ultra-high glass transition temperature (T_g > 450°C) and ultra-low coefficient of thermal expansion (CTE at 0–5 ppm K⁻¹). In this paper, two novel heterocyclic monomers, namely, N,N'-(xanthone-2,7-diyl)bis(4-aminobenzamide) (p-DAXBA) and N,N'-(xanthone-2,7-diyl)bis(3-aminobenzamide) (m-DAXBA), which contain a xanthone moiety, are prepared and polycondensed with pyromellitic dianhydride (PMDA), respectively. PI films (PIa and PIb) with intrinsic high T_g and low CTE are designed from the perspective of rigid conjugate xanthone structure and hydrogen bonding interaction. It is found that the PIa films prepared by p-DAXBA have better linear structure of molecular chains and show relatively higher T_g and lower CTE. The T_g of PIa-40 is greater than 450°C, and CTE can reach as low as 2.7 ppm K⁻¹, tensile strength of 179 MPa, modulus of 5.67 GPa, indicating potential application prospect as a flexible OLED substrate.     

Highly stable and reusable imprinted artificial antibody used for in situ detection and disinfection of pathogens

Sandwich ELISA methods have been widely used for biomarker and pathogen detection because of their high specificity and sensitivity. However, the main drawbacks of this assay are the cost, the time-consuming procedure for the isolation of antibodies and their poor stability. To overcome these restrictions, we herein fabricated artificial antibodies based on imprinting technology and developed a sandwich ELISA for pathogen detection. Both the capture and detection antibodies were obtained via an in situ method, with simplicity, rapidity and low cost. The peroxidase mimics, the CeO₂ nanoparticles, as signal generators were integrated with the detection antibody. The fabricated artificial antibodies exhibited not only natural antibody-like binding affinities and selectivities, but also superior stability and reusability. The detection limit was about 500 CFU mL^–1, which is much lower than that of traditional ELISA methods (10⁴ to 10⁵ CFU mL^–1). Furthermore, the capture antibody can disinfect pathogens in situ.