热活化延迟荧光聚合物及其电致发光器件

热活化延迟荧光(TADF)聚合物,不仅具有小分子TADF材料高的激子利用效率特性,而且还具备分子多样性好、可溶液加工、低成本、以及易实现大面积柔性器件等诸多优势,在近几年受到广泛的关注并展现了良好的应用前景。本文从TADF聚合物分子设计原理、器件结构及发光机理出发,依据TADF聚合物的构筑方法不同,概括了其结构设计策略,详述了各种类型TADF聚合物的分子结构和光电性能及其在有机电致发光器件领域应用的研究进展,最后探讨了TADF聚合物存在的问题,并展望了其发展前景。     

Antidepressant-like effect of triterpenoids extracts from Poria cocos on the CUMS rats by 16S rRNA gene sequencing and LC–MS metabolomics

Abstract

Poria cocos is an edible medicinal mushroom with the effects of inducing diuresis, excreting dampness, invigorating the spleen and tranquilizing the mind. The triterpenoids of Poria cocos as the main active ingredients have shown health benefits of the central nervous system of the human body. Accordingly, this study aimed at further understanding the antidepressant-like effect and a potential mechanism of the triterpenoids extracts from Poria cocos (TPC). As a result, the TPC significantly ameliorated depression-like behaviors on chronic unpredictable mild stress (CUMS) rats, and restored the levels of brain-derived neurotrophic factor and nerve growth factor in the hippocampus of rats. Gut microiota analysis revealed that TPC could increase the biodiversity and markedly regulate the relative abundance of [Prevotella], Allobaculum and Ochrobactrum of CUMS rats. The cecal contents metabolomics pointed to thirteen biomarkers associated with TPC antidepressant effect, which involved in primary bile acid biosynthesis, taurine and hypotaurine metabolism, arginine and proline metabolism. Correlation analysis further showed that there was a strong correlation relationship between the gut microbiota and the cecal contents metabolites, especially compounds involved in energy metabolism, inflammation and immunity. In conclusion, TPC showed a potential antidepressant effect, which was possibly mediated the gut microbiota and cecal contents metabolism.     

1,3-二羟基呫吨酮类化合物的简洁合成及清除亚硝酸根作用研究

以间苯三酚为起始原料,在伊顿试剂的催化作用下,与不同取代水杨酸反应合成1,3-二羟基呫吨酮类化合物3a~3l 12个,收率63%~87%,并探讨了反应机理及结构-反应活性关系.利用紫外分光光度法测定了所合成化合物对亚硝酸盐的清除作用,结果表明,在37℃、pH 3及反应时间为30 min条件下,1,3-呫吨酮类化合物对亚硝酸根均有较好的清除作用,其中化合物3f和3b的清除作用最强,清除率达34%.同时对1,3-二羟基呫吨酮类化合物清除亚硝酸盐的作用机制及构效关系进行了探讨.     

硅氧烷交联的咪唑基团功能化聚苯醚/聚四氟乙烯耐高温质子交换膜

以聚苯醚(PPO)为基体材料, 通过溴甲基化及咪唑基团功能化, 与聚四氟乙烯(PTFE)复合、 硅氧烷基团水解交联及磷酸掺杂, 制备了兼具高磷酸掺杂含量、 高质子电导率和良好机械性能的高温质子交换膜材料. 以甲基咪唑(MeIm)和咪唑基硅氧烷化合物(SiIm)为功能化试剂(其中咪唑基团提供了磷酸作用位点, 同时SiIm中的硅氧烷基团水解后得到Si—O—Si交联网络结构), 提高了膜材料的机械稳定性. 与PTFE的复合进一步增强了膜材料的机械强度. 结果表明, 复合膜具有较高的电导率和一定的机械强度. 当磷酸掺杂质量分数为242.5%时, PPO-50%SiIm-50%MeIm/PTFE复合膜在160 ℃不加湿条件下的电导率为0.09 S/cm, 室温下的断裂拉伸强度为3.6 MPa.     

Molecular insight into structures of monocationic and dicationic ionic liquids in mica slits

Structures of ionic liquids (ILs) 1-decyl-3-methylimidazolium bis(trifluoromethanesulfonyl)azanide ([C₁₀mim][TFSA]) and 1-decyl-dimethylimidazolium bis(trifluoromethanesulfonyl)azanide ([C₁₀(mim)₂](TFSA)₂) in different-sized mica slits have been investigated using molecular dynamics simulations. Ion density and angular distributions for monocationic IL [C₁₀mim][TFSA] were analysed to elucidate the IL structures under different surface charges and especially their changes in the direction perpendicular to the surfaces. [C₁₀mim][TFSA] formes in bilayers, compatible with existing models of ILs with long alkyl chains. For dicationic IL [C₁₀(mim)₂](TFSA)₂, cations adjacent to the mica surface tend to stay parallel to the surface with both positively charged rings absorbed. While near the centre of the slit, dications show the weak tendency of orientation distribution, more random than [C₁₀mim]⁺ ions. Structures of [C₁₀(mim)₂](TFSA)₂ cannot be described by bilayer models. Additionally, the in-plane arrangement of [C₁₀mim][TFSA] is more ordered when K⁺ ions completely neutralise the negative charge of the mica surface, and [C₁₀mim]⁺ ions tend to be located in hexagonal mica lattices with two aluminium atoms in replacement of silicon atoms. [TFSA]^? ions are constrained by the neighbouring K⁺ ions absorbed onto mica lattices.     

Filiform李代数Q_n的Hom-结构

首先证明了有限维Z-阶化李代数上的一个线性算子是Hom-结构的充分必要条件,即它的每个齐次分支也是Hom-结构.然后计算了特征零代数闭域上一类有限维Z-阶化Filiform李代数Qn的齐次Hom-结构,从而决定了Qn的所有Hom-结构.     

Two Aromatic Ester Organoimido Derivatives of Hexa­molybdate: Syntheses,Crystal Structures,and Spectroscopic Studies

Two alkylimido derivatives of hexamolybdate, (Bu₄N)₂[Mo₆O₁₈(≡N‐o‐COOCH₃C₆H₄)] ( 1 ) and (Bu₄N)₂[Mo₆O₁₈(≡N‐o‐COOCH₂CH₃C₆H₄)] ( 2 ), were synthesized in high purity and good yields by the reaction of [(C₄H₉)₄N]₄[α‐Mo₈O₂₆] and methyl anthranilate or ethyl‐o‐aminobenzoate hydrochloride with N,N′‐dicyclohexylcarbodiimide (DCC) as a dehydrating agent in dry acetonitrile solution, which were characterized by elemental analyses, IR, UV/Vis, and ¹H NMR spectroscopy as well as ESI‐MS, and single‐crystal X‐ray diffraction study. Compound 1 crystallizes in the monoclinic space group P2₁/n with one‐dimensional chain structure via intramolecular hydrogen bond. Compound 2 also crystallizes in the monoclinic space group P2₁/n with dimer structure by intramolecular hydrogen bonds and π–π interactions between the pairs of cluster anions.     

Structure,modification, and commercialization of high nickel ternary material (LiNi0.8Co0.1Mn0.1O2 and LiNi0.8Co0.15Al0.05O2) for lithium ion batteries

Journal of Solid State Electrochemistry - LiNi0.8Co0.1Mn0.1O2 (NCM811), as one of the most promising cathode materials for lithium ion batteries, has gained a huge market with its obvious...     

Fast-scan chip-calorimeter measurement on the melting behaviors of melt-crystallized syndiotactic polystyrene

We employed fast-scan chip-calorimeter (FSC) measurement (Flash DSC1) to study the melting of syndiotactic polystyrene after melt-crystallized at various cooling rates as well as after isothermally crystallized at various high temperatures. We attributed the observed double melting peak to a melting-recrystallization process of beta-form crystals upon heating, as evidenced by their variations with different cooling and heating rates. Our experiments demonstrated the advantages of FSC techniques in the investigation of crystallization and melting behaviors of polymer materials.