VA族元素氢化物的紫外光解和多光子电离 Ⅳ. SbH3分子的紫外激光光解和多光子电离

用ArF激光(193 nm)光解锑化氢, 首次获得了在波长为403-700 nm间的SbH_2发射光谱, 其辐射寿命为70±20 ns。还检测到了五十余条Sb(6s→5p)在紫外区的光谱谱线以及离子信号。它们都是多光子过程的产物。     

凝聚玻色子对粒子流密度的影响

基于解析和数值方法计算了两维简谐势阱中旋转玻色子的粒子流密度函数,重点讨论了凝聚玻色子的影响.结果表明：凝聚在基态的玻色子在粒子流密度的空间分布中起着决定性作用.     

一种基于胆固醇的荧光小分子胶凝剂的合成及其胶凝行为

合成并表征了一种含7-硝基苯并-2-氧杂-1,3-二唑基(7-Nitrobenzo-2-oxa-1,3-diazol-4-yl)的胆固醇衍生物(NBD-C), 考察了其在30种溶剂中的胶凝行为. 实验结果表明, NBD-C对乙腈具有很强的胶凝作用, 且该凝胶体系具有显著的剪切触变性. 对干凝胶的显微分析发现, 在不同溶剂中, NBD-C具有不同的聚集结构. 红外光谱(FTIR)、核磁共振光谱(¹H NMR)和荧光光谱研究结果表明, 除了胆固醇的范德华堆积作用之外, 分子间氢键作用也是该化合物聚集的重要驱动力.     

NIR-II Fluorescent Brightness Promoted by “Ring Fusion” for the Detection of Intestinal Inflammation

Fluorophores with emission in the second near-infrared window (NIR-II) have displayed salient advantages for biomedical applications. However, the common strategy of reducing the energy bandgap of fluorophores so as to achieve red-shifted wavelengths always leads to compromised fluorescent brightness. Herein, we propose a molecular design concept of “ring-fusion” to modify the acceptor of AIEgen that can extend the luminous wavelength from NIR-I to NIR-II. The fused-acceptor-containing fluorophore yielded, TTQP, has an enhanced absorption coefficient with a higher brightness in nanoparticle formation compared to its NIR-I emissive counterpart (TTQ-DP) with a non-fused acceptor. Theoretical calculation further confirms that the ring fusion can efficiently promote the rigidity and planarity of the electron-deficient core, leading to a lower reorganization energy and nonradiative decay. The TTQP NPs yielded thus allow sensitive NIR-II fluorescence imaging of vasculature and intestinal inflammation in mice models. Therefore, we anticipate that our work will provide a promising molecular-engineering strategy to enrich the library and broaden the application scope of NIR-II fluorophores.     

Synthesis of Enantiopure Benzo Fused Cyclic Sulfoximines Through Stereoselective [3+2] Cycloaddition between N-tert-Butanesulfinyl [(2-Pyridyl)sulfonyl]-difluoromethyl Ketimines and Arynes

The previously developed stereoselective [3+2] cycloaddition between N-tert-butanesulfinyl ketimines and arynes has been extended to the synthesis of enantiopure [(2-pyridyl)sulfonyl]difluoromethylated cyclic sulfoximines. The use of 2-PySO₂CF₂ as the facilitating group offers new opportunities for the elaboration of the [3+2] cycloaddition products by virtue of the diverse relativity of 2-pyridyl sulfones.     

Molar Mass Dispersity Control by Iodine-mediated Reversible-deactivation Radical Polymerization

Dispersity(D)of polymers has a great effect on the properties of polymeric materials,and therefore how to control D is very important but still a huge challenge in polymer synthesis,especially for reversible-deactivation radical polymerization(RDRP)strategy.Herein,we successfully developed a novel strategy to adjust D of polymers by visible light-controlled reversible complexation mediated living radical polymerization(RCMP)and combination of single-electron transfer-degenerative chain transfer living radical polymerization(SET-DTLRP)at room temperature.In RCMP system,2-iodo-2-methylpropionitrile(CP-I)and ethyl 2-iodo-2-phenylacetate(EIPA)were used as alkyl iodide initiators,by using methyl methacrylate(MMA)as the model monomer and n-butylacrylate(BA)as the end-capping reagent to regulate D of polymers.Subsequently,we successfully prepared the block copolymer PMMA-b-PBA with adjustable D by reactivating the polymer end-chains via SET-DTLRP in the presence of copper wire,fully demonstrating that it is a promising strategy that can keep the"living"feature of polymers while regulating their molar mass dispersities easily.     

Preparation and Luminescence Properties of the Ternary Europium Complex Incorporated into an Inorganic/Polymer Matrix by a Sol-Gel Method

Ternary europium complexes with thenoyltrifluoroacetone (TTA) and phenanthroline (phen) were incorporated into SiO₂/polymer matrix by a sol-gel method. The gels exhibit the characteristic emission bands of europium ion. In addition, Eu³⁺ presents a longer fluorescence lifetime in gel than in the corresponding pure complex powder. Concentration effects on the luminescence intensity were investigated. The reasons that are responsible for above results are also discussed in the context.     

One-pot synthesis of 2,5-disubstituted-1,3,4-thiadiazoles under ultrasonic irradiation

A facile one-pot synthesis of 2,5-disubstituted-1,3,4-thiadiazoles was achieved by ultrasonic irradiation of a mixture of 1- naphthylacetyl chloride,NH_4CNS,CH_2Cl_2 and PEG-400 for 1.5 h at 10-20℃and subsequent irradiation for 1.5h in the presence of N-arylglycine hydrazides.This method requires short time and gives thiadiazoles in high yields.     

考虑弹性地基切向抗力的变截面圆弧壳梁分析

本文根据弹性薄壳理论,考虑了弹性地基径向和切向抗力的影响,解决了变截面圆弧壳地基梁的难题,作者所提出的近似解析法和加权余量法、传递矩阵法较有限单元法简便.     

室内可见光通信发光二极管阵列发射性能的研究

提出了一种基于Lambert辐射模型的发光二极管光源阵列发射天线光照度计算模型,对室内可见光通信发射天线进行了优化设计.分析了光源的空间分布形式、光源间距、光源中心光束与系统光轴夹角以及空间分布层间距等因素对光照度均匀性的影响.通过仿真模拟和分析,得到了圆形阵列天线在照度均匀性和通信传输信号稳定性方面都优于相同光源数目的矩形阵列天线,并且提高了10%左右;同时得出了在满足室内照明情形下,发光二极管阵列发射天线照度均匀度随光源间距及光源中心光束与系统光轴夹角的增加均呈现出先增加后减小的变化趋势,因此,光源间距和光源中心光束与系统光轴夹角均存在最优值;照度均匀度随空间分布层间距的减小而增加,并给出了5 m×5 m×3 m普通房间内发射天线阵列设计参数的最优值,使发射性能得到了优化,同时节省光源数13%,降低了成本.这些研究为发射天线系统的设计提供了理论依据,具有实用价值.