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471.
Formic acid (FA) has attracted extensive attention as a hydrogen storage material. Here, we develop two heterogeneous catalysts based on porous organic polymers (POPs). After loading the Ru species, the catalyst bearing the triphenylphosphine ligand showed excellent performance in terms of activity and stability for the decomposition of FA to produce hydrogen. 相似文献
472.
Qian Pengcheng Qin Yingnan Lyu Yanlong Li Yunfei Wang Lei Wang Shuo Liu Yaqing 《Analytical and bioanalytical chemistry》2019,411(8):1517-1524
Analytical and Bioanalytical Chemistry - Highly sensitive detection of H2O2 and glucose is critical for fundamental research and disease diagnosis. A ratiometric sensor can simultaneously afford... 相似文献
473.
Yifan Lyu Ruizi Peng Hui Liu Hailan Kuai Liuting Mo Da Han Juan Li Weihong Tan 《Chemical science》2020,11(3):631
As the smallest unit of life, cells attract interest due to their structural complexity and functional reliability. Protocells assembled by inanimate components are created as an artificial entity to mimic the structure and some essential properties of a natural cell, and artificial reaction networks are used to program the functions of protocells. Although the bottom-up construction of a protocell that can be considered truly ‘alive’ is still an ambitious goal, these man-made constructs with a certain degree of ‘liveness’ can offer effective tools to understand fundamental processes of cellular life, and have paved the new way for bionic applications. In this review, we highlight both the milestones and recent progress of protocells programmed by artificial reaction networks, including genetic circuits, enzyme-assisted non-genetic circuits, prebiotic mimicking reaction networks, and DNA dynamic circuits. Challenges and opportunities have also been discussed.In this review, the milestones and recent progress of protocells programmed by various types of artificial reaction networks are highlighted. 相似文献
474.
Qian Xu Sigen A Manon Venet Yongsheng Gao Dezhong Zhou Wei Wang Ming Zeng Chiara Rotella Xiaolin Li Xi Wang Jing Lyu Brian J. Rodriguez Wenxin Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(31):10726-10730
Further to conventional linear, branched, crosslinked, and dendritic polymers, single chain cyclized/knotted polymers (SCKPs) have emerged as a new class of polymer structure with unique properties. Herein, the development of bacteria‐resistant SCKPs is reported and the effect of this structure on the resistance of polymer materials to bacteria is investigated. Four SCKPs were synthesized by reversible addition fragmentation chain transfer (RAFT) homopolymerization of multivinyl monomers (MVMs) and then crosslinked by UV light to form SCKP films. Regardless of MVM type used, the resulting SCKP films showed much higher resistance to bacteria, and up to 75 % less bacterial attachment and biofilm formation, in comparison with the corresponding non‐SCKP films. This is due to the altered surface morphology and hydrophobicity of the SCKP films. These results highlight the critical role of the SCKP structure in enhancing the resistance of polymeric materials to bacteria. 相似文献
475.
A self-healing supramolecular polymer composite (HSP-GO) was designed and prepared via incorporation of modified graphene oxide to hyperbranched polymer by hydrogen-bonding interactions.The polymer matrix based on amino-terminated hyperbranched polymer (HSP-NH2) was synthesized by carboxylation,Curtius rearrangement,and amination of hydroxyl-terminated hyperbranched polyester (HP-OH),while the modified graphene oxide was prepared by transformation of hydroxyl to isocyanate and further to carbamate ester.Spectroscopic methods were utilized to characterize the obtained polymer composites.Stress-strain test was selected to carefully study the self-healing property of HSP-GO.It is found that a small amount of modified graphene oxide (up to 2 wt%) improves the glass transition temperature (Tg),tensile strength,Young's modulus,and self-healing efficiency of the polymer composites.After healed at room temperature for 10 min,the addition of modified graphene oxide improves the self-healing efficiency to 3 7% of its original tensile strength.The experiment result shows that the self-healing efficiency is related to the density of hydrogen bonding site and the molecular movement. 相似文献
476.
POE-g-PMAH反应性增容PA1010/PP共混物的性能研究 总被引:4,自引:2,他引:2
乙烯-辛烯共聚物-g-聚马来酸酐(POE-g-PMAH)作为反应性增容剂,采用熔体共混的方法制备了PA1010/PP共混物,通过扫描电镜(SEM)、力学性能、傅立叶变换红外光谱(FTIR)和示差扫描量热(DSC)测试,研究了POE-g-PMAH对PA1010/PP共混物的增容作用.结果表明,POE-g-PMAH的加入可以减小共混物的相区尺寸,当PA1010/PP/POE-g-PMAH=70/30/15时,分散相尺寸小而均匀;FTIR结果表明接枝在POE上的马来酸酐基团和PA1010在熔融共混期间发生了化学反应;DSC研究结果表明共混体系中PA1010和PP的结晶温度和结晶度随POE-g-PMAH的加入而降低,表明POE-g-PMAH的增容作用对PA1010和PP的结晶有抑制作用.力学性能测试结果表明随着POE-g-PMAH的增加,共混物的冲击强度逐渐增加,当POE-g-PMAH含量增加到15%时,干态冲击强度达到21.13 kJ/m2,是不加增容剂的3.1倍,而拉伸和弯曲强度可以保持较高水平.POE-g-PMAH的增容机理在于其支链中的马来酸酐能与PA1010中的胺基(NH2—)发生化学反应,而主链POE与PP有较好的亲和性,从而降低界面张力,减少相区尺寸,大幅度提高力学性能. 相似文献
477.
不同分子量的高密度聚乙烯与茂金属线型低密度聚乙烯的相容性 总被引:1,自引:0,他引:1
采用动态流变学测试和结晶动力学的方法研究了两种分子量的高密度聚乙烯(HDPE)与茂金属线型低密度聚乙烯(m-LLDPE)共混体系的相容性.流变学研究表明,HDPE/m-LLDPE共混物在低ω区域lgG′-lgω关系曲线偏离线性规律,在熔融态为非均相体系.DSC分析发现HDPE/m-LLDPE共混物体系中HDPE的熔点随着m-LLDPE含量的增多而逐渐下降,说明HDPE与m-LLDPE二者具有机械相容性.当HDPE在m-LLDPE的熔体中等温结晶,分子量较高的HDPE结晶速率与纯HDPE相近,m-LLDPE的含量变化对Avrami指数n的影响不大;分子量较低的HDPE指数n和半结晶时间t1/2随m-LLDPE含量的增加逐渐增大,结晶速率随着m-LLDPE含量的增加逐渐下降,表明熔融态的m-LLDPE和HDPE存在着较强的分子间相互作用,二者具有一定的相容性. 相似文献
478.
Yan Lyu Li-Qing Zhang Wei Zheng Qing-Chao Pan 《International Journal of Theoretical Physics》2010,49(8):1759-1767
The radial parts of Dirac equation between the outer black hole horizon and the cosmological horizon are solved in Reissner-Nordström de Sitter (RNdS) space when it is at the phase transition point. We use an accurate polynomial approximation to approximate the modified tortoise coordinate \(\hat{r}_{*}\) in order to get the inverse function \(r=r(\hat{r}_{*})\) and the potential \(V(\hat{r}_{*})\). Then we use a quantum mechanical method to solve the wave equation numerically. We consider two cases, one is when the two horizons are lying close to each other, the other is when the two horizons are widely separated. 相似文献
479.
480.